ViewVC Help
View File | Revision Log | Show Annotations | Download File
/cvs/AnyEvent-MP/MP.pm
Revision: 1.7
Committed: Sat Aug 1 15:04:30 2009 UTC (14 years, 9 months ago) by root
Branch: MAIN
Changes since 1.6: +12 -3 lines
Log Message:
*** empty log message ***

File Contents

# Content
1 =head1 NAME
2
3 AnyEvent::MP - multi-processing/message-passing framework
4
5 =head1 SYNOPSIS
6
7 use AnyEvent::MP;
8
9 NODE # returns this node identifier
10 $NODE # contains this node identifier
11
12 snd $port, type => data...;
13
14 rcv $port, smartmatch => $cb->($port, @msg);
15
16 # examples:
17 rcv $port2, ping => sub { snd $_[0], "pong"; 0 };
18 rcv $port1, pong => sub { warn "pong received\n" };
19 snd $port2, ping => $port1;
20
21 # more, smarter, matches (_any_ is exported by this module)
22 rcv $port, [child_died => $pid] => sub { ...
23 rcv $port, [_any_, _any_, 3] => sub { .. $_[2] is 3
24
25 =head1 DESCRIPTION
26
27 This module (-family) implements a simple message passing framework.
28
29 Despite its simplicity, you can securely message other processes running
30 on the same or other hosts.
31
32 At the moment, this module family is severly brokena nd underdocumented,
33 so do not use. This was uploaded mainly to resreve the CPAN namespace -
34 stay tuned!
35
36 =head1 CONCEPTS
37
38 =over 4
39
40 =item port
41
42 A port is something you can send messages to with the C<snd> function, and
43 you can register C<rcv> handlers with. All C<rcv> handlers will receive
44 messages they match, messages will not be queued.
45
46 =item port id - C<noderef#portname>
47
48 A port id is always the noderef, a hash-mark (C<#>) as separator, followed
49 by a port name (a printable string of unspecified format).
50
51 =item node
52
53 A node is a single process containing at least one port - the node
54 port. You can send messages to node ports to let them create new ports,
55 among other things.
56
57 Initially, nodes are either private (single-process only) or hidden
58 (connected to a master node only). Only when they epxlicitly "become
59 public" can you send them messages from unrelated other nodes.
60
61 =item noderef - C<host:port,host:port...>, C<id@noderef>, C<id>
62
63 A noderef is a string that either uniquely identifies a given node (for
64 private and hidden nodes), or contains a recipe on how to reach a given
65 node (for public nodes).
66
67 =back
68
69 =head1 VARIABLES/FUNCTIONS
70
71 =over 4
72
73 =cut
74
75 package AnyEvent::MP;
76
77 use AnyEvent::MP::Util ();
78 use AnyEvent::MP::Node;
79 use AnyEvent::MP::Transport;
80
81 use utf8;
82 use common::sense;
83
84 use Carp ();
85
86 use AE ();
87
88 use base "Exporter";
89
90 our $VERSION = '0.01';
91 our @EXPORT = qw(NODE $NODE $PORT snd rcv _any_);
92
93 our $DEFAULT_SECRET;
94 our $DEFAULT_PORT = "4040";
95
96 our $CONNECT_INTERVAL = 5; # new connect every 5s, at least
97 our $CONNECT_TIMEOUT = 30; # includes handshake
98
99 sub default_secret {
100 unless (defined $DEFAULT_SECRET) {
101 if (open my $fh, "<$ENV{HOME}/.aemp-secret") {
102 sysread $fh, $DEFAULT_SECRET, -s $fh;
103 } else {
104 $DEFAULT_SECRET = AnyEvent::MP::Util::nonce 32;
105 }
106 }
107
108 $DEFAULT_SECRET
109 }
110
111 =item NODE / $NODE
112
113 The C<NODE ()> function and the C<$NODE> variable contain the noderef of
114 the local node. The value is initialised by a call to C<become_public> or
115 C<become_slave>, after which all local port identifiers become invalid.
116
117 =cut
118
119 our $UNIQ = sprintf "%x.%x", $$, time; # per-process/node unique cookie
120 our $ID = "a0";
121 our $PUBLIC = 0;
122 our $NODE;
123 our $PORT;
124
125 our %NODE; # node id to transport mapping, or "undef", for local node
126 our %PORT; # local ports
127 our %LISTENER; # local transports
128
129 sub NODE() { $NODE }
130
131 {
132 use POSIX ();
133 my $nodename = (POSIX::uname)[1];
134 $NODE = "$$\@$nodename";
135 }
136
137 sub _ANY_() { 1 }
138 sub _any_() { \&_ANY_ }
139
140 sub add_node {
141 my ($noderef) = @_;
142
143 return $NODE{$noderef}
144 if exists $NODE{$noderef};
145
146 for (split /,/, $noderef) {
147 return $NODE{$noderef} = $NODE{$_}
148 if exists $NODE{$_};
149 }
150
151 # for indirect sends, use a different class
152 my $node = new AnyEvent::MP::Node::Direct $noderef;
153
154 $NODE{$_} = $node
155 for $noderef, split /,/, $noderef;
156
157 $node
158 }
159
160 =item snd $portid, type => @data
161
162 =item snd $portid, @msg
163
164 Send the given message to the given port ID, which can identify either a
165 local or a remote port.
166
167 While the message can be about anything, it is highly recommended to use
168 a constant string as first element.
169
170 The message data effectively becomes read-only after a call to this
171 function: modifying any argument is not allowed and can cause many
172 problems.
173
174 The type of data you can transfer depends on the transport protocol: when
175 JSON is used, then only strings, numbers and arrays and hashes consisting
176 of those are allowed (no objects). When Storable is used, then anything
177 that Storable can serialise and deserialise is allowed, and for the local
178 node, anything can be passed.
179
180 =cut
181
182 sub snd(@) {
183 my ($noderef, $port) = split /#/, shift, 2;
184
185 add_node $noderef
186 unless exists $NODE{$noderef};
187
188 $NODE{$noderef}->send (["$port", [@_]]);
189 }
190
191 =item rcv $portid, type => $callback->(@msg)
192
193 =item rcv $portid, $smartmatch => $callback->(@msg)
194
195 =item rcv $portid, [$smartmatch...] => $callback->(@msg)
196
197 Register a callback on the port identified by C<$portid>, which I<must> be
198 a local port.
199
200 The callback has to return a true value when its work is done, after
201 which is will be removed, or a false value in which case it will stay
202 registered.
203
204 If the match is an array reference, then it will be matched against the
205 first elements of the message, otherwise only the first element is being
206 matched.
207
208 Any element in the match that is specified as C<_any_> (a function
209 exported by this module) matches any single element of the message.
210
211 While not required, it is highly recommended that the first matching
212 element is a string identifying the message. The one-string-only match is
213 also the most efficient match (by far).
214
215 =cut
216
217 sub rcv($@) {
218 my ($port, $match, $cb) = @_;
219
220 my $port = $PORT{$port}
221 or do {
222 my ($noderef, $lport) = split /#/, $port;
223 "AnyEvent::MP::Node::Self" eq ref $NODE{$noderef}
224 or Carp::croak "$port: can only rcv on local ports";
225
226 $PORT{$lport}
227 or Carp::croak "$port: port does not exist";
228
229 $PORT{$port} = $PORT{$lport} # also return
230 };
231
232 if (!ref $match) {
233 push @{ $port->{rc0}{$match} }, [$cb];
234 } elsif (("ARRAY" eq ref $match && !ref $match->[0])) {
235 my ($type, @match) = @$match;
236 @match
237 ? push @{ $port->{rcv}{$match->[0]} }, [$cb, \@match]
238 : push @{ $port->{rc0}{$match->[0]} }, [$cb];
239 } else {
240 push @{ $port->{any} }, [$cb, $match];
241 }
242 }
243
244 sub _inject {
245 my ($port, $msg) = @{+shift};
246
247 $port = $PORT{$port}
248 or return;
249
250 @_ = @$msg;
251
252 for (@{ $port->{rc0}{$msg->[0]} }) {
253 $_ && &{$_->[0]}
254 && undef $_;
255 }
256
257 for (@{ $port->{rcv}{$msg->[0]} }) {
258 $_ && [@_[1..$#{$_->[1]}]] ~~ $_->[1]
259 && &{$_->[0]}
260 && undef $_;
261 }
262
263 for (@{ $port->{any} }) {
264 $_ && [@_[0..$#{$_->[1]}]] ~~ $_->[1]
265 && &{$_->[0]}
266 && undef $_;
267 }
268 }
269
270 sub normalise_noderef($) {
271 my ($noderef) = @_;
272
273 my $cv = AE::cv;
274 my @res;
275
276 $cv->begin (sub {
277 my %seen;
278 my @refs;
279 for (sort { $a->[0] <=> $b->[0] } @res) {
280 push @refs, $_->[1] unless $seen{$_->[1]}++
281 }
282 shift->send (join ",", @refs);
283 });
284
285 $noderef = $DEFAULT_PORT unless length $noderef;
286
287 my $idx;
288 for my $t (split /,/, $noderef) {
289 my $pri = ++$idx;
290
291 #TODO: this should be outside normalise_noderef and in become_public
292 if ($t =~ /^\d*$/) {
293 my $nodename = (POSIX::uname)[1];
294
295 $cv->begin;
296 AnyEvent::Socket::resolve_sockaddr $nodename, $t || "aemp=$DEFAULT_PORT", "tcp", 0, undef, sub {
297 for (@_) {
298 my ($service, $host) = AnyEvent::Socket::unpack_sockaddr $_->[3];
299 push @res, [
300 $pri += 1e-5,
301 AnyEvent::Socket::format_hostport AnyEvent::Socket::format_address $host, $service
302 ];
303 }
304 $cv->end;
305 };
306
307 # my (undef, undef, undef, undef, @ipv4) = gethostbyname $nodename;
308 #
309 # for (@ipv4) {
310 # push @res, [
311 # $pri,
312 # AnyEvent::Socket::format_hostport AnyEvent::Socket::format_address $_, $t || $DEFAULT_PORT,
313 # ];
314 # }
315 } else {
316 my ($host, $port) = AnyEvent::Socket::parse_hostport $t, "aemp=$DEFAULT_PORT"
317 or Carp::croak "$t: unparsable transport descriptor";
318
319 $cv->begin;
320 AnyEvent::Socket::resolve_sockaddr $host, $port, "tcp", 0, undef, sub {
321 for (@_) {
322 my ($service, $host) = AnyEvent::Socket::unpack_sockaddr $_->[3];
323 push @res, [
324 $pri += 1e-5,
325 AnyEvent::Socket::format_hostport AnyEvent::Socket::format_address $host, $service
326 ];
327 }
328 $cv->end;
329 }
330 }
331 }
332
333 $cv->end;
334
335 $cv
336 }
337
338 sub become_public {
339 return if $PUBLIC;
340
341 my $noderef = join ",", ref $_[0] ? @{+shift} : shift;
342 my @args = @_;
343
344 $NODE = (normalise_noderef $noderef)->recv;
345
346 for my $t (split /,/, $NODE) {
347 $NODE{$t} = $NODE{""};
348
349 my ($host, $port) = AnyEvent::Socket::parse_hostport $t;
350
351 $LISTENER{$t} = AnyEvent::MP::Transport::mp_server $host, $port,
352 @args,
353 on_error => sub {
354 die "on_error<@_>\n";#d#
355 },
356 on_connect => sub {
357 my ($tp) = @_;
358
359 $NODE{$tp->{remote_id}} = $_[0];
360 },
361 sub {
362 my ($tp) = @_;
363
364 $NODE{"$tp->{peerhost}:$tp->{peerport}"} = $tp;
365 },
366 ;
367 }
368
369 $PUBLIC = 1;
370 }
371
372 =back
373
374 =head1 NODE MESSAGES
375
376 Nodes understand the following messages sent to them. Many of them take
377 arguments called C<@reply>, which will simply be used to compose a reply
378 message - C<$reply[0]> is the port to reply to, C<$reply[1]> the type and
379 the remaining arguments are simply the message data.
380
381 =over 4
382
383 =cut
384
385 #############################################################################
386 # self node code
387
388 sub _new_port($) {
389 my ($name) = @_;
390
391 my ($noderef, $portname) = split /#/, $name;
392
393 $PORT{$name} =
394 $PORT{$portname} = {
395 names => [$name, $portname],
396 };
397 }
398
399 $NODE{""} = new AnyEvent::MP::Node::Self noderef => $NODE;
400 _new_port "";
401
402 =item devnull => ...
403
404 Generic data sink/CPU heat conversion.
405
406 =cut
407
408 rcv "", devnull => sub { () };
409
410 =item relay => $port, @msg
411
412 Simply forwards the message to the given port.
413
414 =cut
415
416 rcv "", relay => sub { \&snd; () };
417
418 =item eval => $string[ @reply]
419
420 Evaluates the given string. If C<@reply> is given, then a message of the
421 form C<@reply, $@, @evalres> is sent.
422
423 Example: crash another node.
424
425 snd $othernode, eval => "exit";
426
427 =cut
428
429 rcv "", eval => sub {
430 my (undef, $string, @reply) = @_;
431 my @res = eval $string;
432 snd @reply, "$@", @res if @reply;
433 ()
434 };
435
436 =item time => @reply
437
438 Replies the the current node time to C<@reply>.
439
440 Example: tell the current node to send the current time to C<$myport> in a
441 C<timereply> message.
442
443 snd $NODE, time => $myport, timereply => 1, 2;
444 # => snd $myport, timereply => 1, 2, <time>
445
446 =cut
447
448 rcv "", time => sub { shift; snd @_, AE::time; () };
449
450 =back
451
452 =head1 SEE ALSO
453
454 L<AnyEvent>.
455
456 =head1 AUTHOR
457
458 Marc Lehmann <schmorp@schmorp.de>
459 http://home.schmorp.de/
460
461 =cut
462
463 1
464