ViewVC Help
View File | Revision Log | Show Annotations | Download File
/cvs/AnyEvent-MP/MP.pm
(Generate patch)

Comparing AnyEvent-MP/MP.pm (file contents):
Revision 1.26 by root, Tue Aug 4 22:05:43 2009 UTC vs.
Revision 1.33 by root, Wed Aug 5 22:40:51 2009 UTC

43 43
44=over 4 44=over 4
45 45
46=item port 46=item port
47 47
48A port is something you can send messages to with the C<snd> function, and 48A port is something you can send messages to (with the C<snd> function).
49you can register C<rcv> handlers with. All C<rcv> handlers will receive 49
50messages they match, messages will not be queued. 50Some ports allow you to register C<rcv> handlers that can match specific
51messages. All C<rcv> handlers will receive messages they match, messages
52will not be queued.
51 53
52=item port id - C<noderef#portname> 54=item port id - C<noderef#portname>
53 55
54A port id is always the noderef, a hash-mark (C<#>) as separator, followed 56A port id is normaly the concatenation of a noderef, a hash-mark (C<#>) as
55by a port name (a printable string of unspecified format). 57separator, and a port name (a printable string of unspecified format). An
58exception is the the node port, whose ID is identical to its node
59reference.
56 60
57=item node 61=item node
58 62
59A node is a single process containing at least one port - the node 63A node is a single process containing at least one port - the node
60port. You can send messages to node ports to let them create new ports, 64port. You can send messages to node ports to find existing ports or to
61among other things. 65create new ports, among other things.
62 66
63Initially, nodes are either private (single-process only) or hidden 67Nodes are either private (single-process only), slaves (connected to a
64(connected to a master node only). Only when they epxlicitly "become 68master node only) or public nodes (connectable from unrelated nodes).
65public" can you send them messages from unrelated other nodes.
66 69
67=item noderef - C<host:port,host:port...>, C<id@noderef>, C<id> 70=item noderef - C<host:port,host:port...>, C<id@noderef>, C<id>
68 71
69A noderef is a string that either uniquely identifies a given node (for 72A node reference is a string that either simply identifies the node (for
70private and hidden nodes), or contains a recipe on how to reach a given 73private and slave nodes), or contains a recipe on how to reach a given
71node (for public nodes). 74node (for public nodes).
75
76This recipe is simply a comma-separated list of C<address:port> pairs (for
77TCP/IP, other protocols might look different).
78
79Node references come in two flavours: resolved (containing only numerical
80addresses) or unresolved (where hostnames are used instead of addresses).
81
82Before using an unresolved node reference in a message you first have to
83resolve it.
72 84
73=back 85=back
74 86
75=head1 VARIABLES/FUNCTIONS 87=head1 VARIABLES/FUNCTIONS
76 88
91use base "Exporter"; 103use base "Exporter";
92 104
93our $VERSION = '0.1'; 105our $VERSION = '0.1';
94our @EXPORT = qw( 106our @EXPORT = qw(
95 NODE $NODE *SELF node_of _any_ 107 NODE $NODE *SELF node_of _any_
96 become_slave become_public 108 resolve_node initialise_node
97 snd rcv mon kil reg psub 109 snd rcv mon kil reg psub
98 port 110 port
99); 111);
100 112
101our $SELF; 113our $SELF;
111The C<NODE> function returns, and the C<$NODE> variable contains 123The C<NODE> function returns, and the C<$NODE> variable contains
112the noderef of the local node. The value is initialised by a call 124the noderef of the local node. The value is initialised by a call
113to C<become_public> or C<become_slave>, after which all local port 125to C<become_public> or C<become_slave>, after which all local port
114identifiers become invalid. 126identifiers become invalid.
115 127
116=item $noderef = node_of $portid 128=item $noderef = node_of $port
117 129
118Extracts and returns the noderef from a portid or a noderef. 130Extracts and returns the noderef from a portid or a noderef.
131
132=item $cv = resolve_node $noderef
133
134Takes an unresolved node reference that may contain hostnames and
135abbreviated IDs, resolves all of them and returns a resolved node
136reference.
137
138In addition to C<address:port> pairs allowed in resolved noderefs, the
139following forms are supported:
140
141=over 4
142
143=item the empty string
144
145An empty-string component gets resolved as if the default port (4040) was
146specified.
147
148=item naked port numbers (e.g. C<1234>)
149
150These are resolved by prepending the local nodename and a colon, to be
151further resolved.
152
153=item hostnames (e.g. C<localhost:1234>, C<localhost>)
154
155These are resolved by using AnyEvent::DNS to resolve them, optionally
156looking up SRV records for the C<aemp=4040> port, if no port was
157specified.
158
159=back
119 160
120=item $SELF 161=item $SELF
121 162
122Contains the current port id while executing C<rcv> callbacks or C<psub> 163Contains the current port id while executing C<rcv> callbacks or C<psub>
123blocks. 164blocks.
126 167
127Due to some quirks in how perl exports variables, it is impossible to 168Due to some quirks in how perl exports variables, it is impossible to
128just export C<$SELF>, all the symbols called C<SELF> are exported by this 169just export C<$SELF>, all the symbols called C<SELF> are exported by this
129module, but only C<$SELF> is currently used. 170module, but only C<$SELF> is currently used.
130 171
131=item snd $portid, type => @data 172=item snd $port, type => @data
132 173
133=item snd $portid, @msg 174=item snd $port, @msg
134 175
135Send the given message to the given port ID, which can identify either 176Send the given message to the given port ID, which can identify either
136a local or a remote port, and can be either a string or soemthignt hat 177a local or a remote port, and can be either a string or soemthignt hat
137stringifies a sa port ID (such as a port object :). 178stringifies a sa port ID (such as a port object :).
138 179
148JSON is used, then only strings, numbers and arrays and hashes consisting 189JSON is used, then only strings, numbers and arrays and hashes consisting
149of those are allowed (no objects). When Storable is used, then anything 190of those are allowed (no objects). When Storable is used, then anything
150that Storable can serialise and deserialise is allowed, and for the local 191that Storable can serialise and deserialise is allowed, and for the local
151node, anything can be passed. 192node, anything can be passed.
152 193
153=item kil $portid[, @reason]
154
155Kill the specified port with the given C<@reason>.
156
157If no C<@reason> is specified, then the port is killed "normally" (linked
158ports will not be kileld, or even notified).
159
160Otherwise, linked ports get killed with the same reason (second form of
161C<mon>, see below).
162
163Runtime errors while evaluating C<rcv> callbacks or inside C<psub> blocks
164will be reported as reason C<< die => $@ >>.
165
166Transport/communication errors are reported as C<< transport_error =>
167$message >>.
168
169=item $guard = mon $portid, $cb->(@reason)
170
171=item $guard = mon $portid, $otherport
172
173=item $guard = mon $portid, $otherport, @msg
174
175Monitor the given port and do something when the port is killed.
176
177In the first form, the callback is simply called with any number
178of C<@reason> elements (no @reason means that the port was deleted
179"normally"). Note also that I<< the callback B<must> never die >>, so use
180C<eval> if unsure.
181
182In the second form, the other port will be C<kil>'ed with C<@reason>, iff
183a @reason was specified, i.e. on "normal" kils nothing happens, while
184under all other conditions, the other port is killed with the same reason.
185
186In the last form, a message of the form C<@msg, @reason> will be C<snd>.
187
188Example: call a given callback when C<$port> is killed.
189
190 mon $port, sub { warn "port died because of <@_>\n" };
191
192Example: kill ourselves when C<$port> is killed abnormally.
193
194 mon $port, $self;
195
196Example: send us a restart message another C<$port> is killed.
197
198 mon $port, $self => "restart";
199
200=cut
201
202sub mon {
203 my ($noderef, $port, $cb) = ((split /#/, shift, 2), shift);
204
205 my $node = $NODE{$noderef} || add_node $noderef;
206
207 #TODO: ports must not be references
208 if (!ref $cb or "AnyEvent::MP::Port" eq ref $cb) {
209 if (@_) {
210 # send a kill info message
211 my (@msg) = ($cb, @_);
212 $cb = sub { snd @msg, @_ };
213 } else {
214 # simply kill other port
215 my $port = $cb;
216 $cb = sub { kil $port, @_ if @_ };
217 }
218 }
219
220 $node->monitor ($port, $cb);
221
222 defined wantarray
223 and AnyEvent::Util::guard { $node->unmonitor ($port, $cb) }
224}
225
226=item $guard = mon_guard $port, $ref, $ref...
227
228Monitors the given C<$port> and keeps the passed references. When the port
229is killed, the references will be freed.
230
231Optionally returns a guard that will stop the monitoring.
232
233This function is useful when you create e.g. timers or other watchers and
234want to free them when the port gets killed:
235
236 $port->rcv (start => sub {
237 my $timer; $timer = mon_guard $port, AE::timer 1, 1, sub {
238 undef $timer if 0.9 < rand;
239 });
240 });
241
242=cut
243
244sub mon_guard {
245 my ($port, @refs) = @_;
246
247 mon $port, sub { 0 && @refs }
248}
249
250=item lnk $port1, $port2
251
252Link two ports. This is simply a shorthand for:
253
254 mon $port1, $port2;
255 mon $port2, $port1;
256
257It means that if either one is killed abnormally, the other one gets
258killed as well.
259
260=item $local_port = port 194=item $local_port = port
261 195
262Create a new local port object that supports message matching. 196Create a new local port object that can be used either as a pattern
197matching port ("full port") or a single-callback port ("miniport"),
198depending on how C<rcv> callbacks are bound to the object.
263 199
264=item $portid = port { my @msg = @_; $finished } 200=item $port = port { my @msg = @_; $finished }
265 201
266Creates a "mini port", that is, a very lightweight port without any 202Creates a "miniport", that is, a very lightweight port without any pattern
267pattern matching behind it, and returns its ID. 203matching behind it, and returns its ID. Semantically the same as creating
204a port and calling C<rcv $port, $callback> on it.
268 205
269The block will be called for every message received on the port. When the 206The block will be called for every message received on the port. When the
270callback returns a true value its job is considered "done" and the port 207callback returns a true value its job is considered "done" and the port
271will be destroyed. Otherwise it will stay alive. 208will be destroyed. Otherwise it will stay alive.
272 209
273The message will be passed as-is, no extra argument (i.e. no port id) will 210The message will be passed as-is, no extra argument (i.e. no port id) will
274be passed to the callback. 211be passed to the callback.
275 212
276If you need the local port id in the callback, this works nicely: 213If you need the local port id in the callback, this works nicely:
277 214
278 my $port; $port = miniport { 215 my $port; $port = port {
279 snd $otherport, reply => $port; 216 snd $otherport, reply => $port;
280 }; 217 };
281 218
282=cut 219=cut
220
221sub rcv($@);
283 222
284sub port(;&) { 223sub port(;&) {
285 my $id = "$UNIQ." . $ID++; 224 my $id = "$UNIQ." . $ID++;
286 my $port = "$NODE#$id"; 225 my $port = "$NODE#$id";
287 226
288 if (@_) { 227 if (@_) {
228 rcv $port, shift;
229 } else {
230 $PORT{$id} = sub { }; # nop
231 }
232
233 $port
234}
235
236=item reg $port, $name
237
238Registers the given port under the name C<$name>. If the name already
239exists it is replaced.
240
241A port can only be registered under one well known name.
242
243A port automatically becomes unregistered when it is killed.
244
245=cut
246
247sub reg(@) {
248 my ($port, $name) = @_;
249
250 $REG{$name} = $port;
251}
252
253=item rcv $port, $callback->(@msg)
254
255Replaces the callback on the specified miniport (after converting it to
256one if required).
257
258=item rcv $port, tagstring => $callback->(@msg), ...
259
260=item rcv $port, $smartmatch => $callback->(@msg), ...
261
262=item rcv $port, [$smartmatch...] => $callback->(@msg), ...
263
264Register callbacks to be called on matching messages on the given full
265port (after converting it to one if required).
266
267The callback has to return a true value when its work is done, after
268which is will be removed, or a false value in which case it will stay
269registered.
270
271The global C<$SELF> (exported by this module) contains C<$port> while
272executing the callback.
273
274Runtime errors wdurign callback execution will result in the port being
275C<kil>ed.
276
277If the match is an array reference, then it will be matched against the
278first elements of the message, otherwise only the first element is being
279matched.
280
281Any element in the match that is specified as C<_any_> (a function
282exported by this module) matches any single element of the message.
283
284While not required, it is highly recommended that the first matching
285element is a string identifying the message. The one-string-only match is
286also the most efficient match (by far).
287
288=cut
289
290sub rcv($@) {
291 my $port = shift;
292 my ($noderef, $portid) = split /#/, $port, 2;
293
294 ($NODE{$noderef} || add_node $noderef) == $NODE{""}
295 or Carp::croak "$port: rcv can only be called on local ports, caught";
296
297 if (@_ == 1) {
289 my $cb = shift; 298 my $cb = shift;
299 delete $PORT_DATA{$portid};
290 $PORT{$id} = sub { 300 $PORT{$portid} = sub {
291 local $SELF = $port; 301 local $SELF = $port;
292 eval { 302 eval {
293 &$cb 303 &$cb
294 and kil $id; 304 and kil $port;
295 }; 305 };
296 _self_die if $@; 306 _self_die if $@;
297 }; 307 };
298 } else { 308 } else {
309 my $self = $PORT_DATA{$portid} ||= do {
299 my $self = bless { 310 my $self = bless {
300 id => "$NODE#$id", 311 id => $port,
301 }, "AnyEvent::MP::Port"; 312 }, "AnyEvent::MP::Port";
302 313
303 $PORT_DATA{$id} = $self;
304 $PORT{$id} = sub { 314 $PORT{$portid} = sub {
305 local $SELF = $port; 315 local $SELF = $port;
306 316
307 eval { 317 eval {
308 for (@{ $self->{rc0}{$_[0]} }) { 318 for (@{ $self->{rc0}{$_[0]} }) {
309 $_ && &{$_->[0]} 319 $_ && &{$_->[0]}
310 && undef $_; 320 && undef $_;
311 } 321 }
312 322
313 for (@{ $self->{rcv}{$_[0]} }) { 323 for (@{ $self->{rcv}{$_[0]} }) {
314 $_ && [@_[1 .. @{$_->[1]}]] ~~ $_->[1] 324 $_ && [@_[1 .. @{$_->[1]}]] ~~ $_->[1]
315 && &{$_->[0]} 325 && &{$_->[0]}
316 && undef $_; 326 && undef $_;
317 } 327 }
318 328
319 for (@{ $self->{any} }) { 329 for (@{ $self->{any} }) {
320 $_ && [@_[0 .. $#{$_->[1]}]] ~~ $_->[1] 330 $_ && [@_[0 .. $#{$_->[1]}]] ~~ $_->[1]
321 && &{$_->[0]} 331 && &{$_->[0]}
322 && undef $_; 332 && undef $_;
333 }
323 } 334 };
335 _self_die if $@;
324 }; 336 };
325 _self_die if $@; 337
338 $self
326 }; 339 };
327 }
328 340
329 $port
330}
331
332=item reg $portid, $name
333
334Registers the given port under the name C<$name>. If the name already
335exists it is replaced.
336
337A port can only be registered under one well known name.
338
339A port automatically becomes unregistered when it is killed.
340
341=cut
342
343sub reg(@) {
344 my ($portid, $name) = @_;
345
346 $REG{$name} = $portid;
347}
348
349=item rcv $portid, tagstring => $callback->(@msg), ...
350
351=item rcv $portid, $smartmatch => $callback->(@msg), ...
352
353=item rcv $portid, [$smartmatch...] => $callback->(@msg), ...
354
355Register callbacks to be called on matching messages on the given port.
356
357The callback has to return a true value when its work is done, after
358which is will be removed, or a false value in which case it will stay
359registered.
360
361The global C<$SELF> (exported by this module) contains C<$portid> while
362executing the callback.
363
364Runtime errors wdurign callback execution will result in the port being
365C<kil>ed.
366
367If the match is an array reference, then it will be matched against the
368first elements of the message, otherwise only the first element is being
369matched.
370
371Any element in the match that is specified as C<_any_> (a function
372exported by this module) matches any single element of the message.
373
374While not required, it is highly recommended that the first matching
375element is a string identifying the message. The one-string-only match is
376also the most efficient match (by far).
377
378=cut
379
380sub rcv($@) {
381 my ($noderef, $port) = split /#/, shift, 2;
382
383 ($NODE{$noderef} || add_node $noderef) == $NODE{""}
384 or Carp::croak "$noderef#$port: rcv can only be called on local ports, caught";
385
386 my $self = $PORT_DATA{$port}
387 or Carp::croak "$noderef#$port: rcv can only be called on message matching ports, caught";
388
389 "AnyEvent::MP::Port" eq ref $self 341 "AnyEvent::MP::Port" eq ref $self
390 or Carp::croak "$noderef#$port: rcv can only be called on message matching ports, caught"; 342 or Carp::croak "$port: rcv can only be called on message matching ports, caught";
391 343
392 while (@_) { 344 while (@_) {
393 my ($match, $cb) = splice @_, 0, 2; 345 my ($match, $cb) = splice @_, 0, 2;
394 346
395 if (!ref $match) { 347 if (!ref $match) {
396 push @{ $self->{rc0}{$match} }, [$cb]; 348 push @{ $self->{rc0}{$match} }, [$cb];
397 } elsif (("ARRAY" eq ref $match && !ref $match->[0])) { 349 } elsif (("ARRAY" eq ref $match && !ref $match->[0])) {
398 my ($type, @match) = @$match; 350 my ($type, @match) = @$match;
399 @match 351 @match
400 ? push @{ $self->{rcv}{$match->[0]} }, [$cb, \@match] 352 ? push @{ $self->{rcv}{$match->[0]} }, [$cb, \@match]
401 : push @{ $self->{rc0}{$match->[0]} }, [$cb]; 353 : push @{ $self->{rc0}{$match->[0]} }, [$cb];
402 } else { 354 } else {
403 push @{ $self->{any} }, [$cb, $match]; 355 push @{ $self->{any} }, [$cb, $match];
356 }
404 } 357 }
405 } 358 }
359
360 $port
406} 361}
407 362
408=item $closure = psub { BLOCK } 363=item $closure = psub { BLOCK }
409 364
410Remembers C<$SELF> and creates a closure out of the BLOCK. When the 365Remembers C<$SELF> and creates a closure out of the BLOCK. When the
441 $res 396 $res
442 } 397 }
443 } 398 }
444} 399}
445 400
401=item $guard = mon $port, $cb->(@reason)
402
403=item $guard = mon $port, $otherport
404
405=item $guard = mon $port, $otherport, @msg
406
407Monitor the given port and do something when the port is killed.
408
409In the first form, the callback is simply called with any number
410of C<@reason> elements (no @reason means that the port was deleted
411"normally"). Note also that I<< the callback B<must> never die >>, so use
412C<eval> if unsure.
413
414In the second form, the other port will be C<kil>'ed with C<@reason>, iff
415a @reason was specified, i.e. on "normal" kils nothing happens, while
416under all other conditions, the other port is killed with the same reason.
417
418In the last form, a message of the form C<@msg, @reason> will be C<snd>.
419
420Example: call a given callback when C<$port> is killed.
421
422 mon $port, sub { warn "port died because of <@_>\n" };
423
424Example: kill ourselves when C<$port> is killed abnormally.
425
426 mon $port, $self;
427
428Example: send us a restart message another C<$port> is killed.
429
430 mon $port, $self => "restart";
431
432=cut
433
434sub mon {
435 my ($noderef, $port) = split /#/, shift, 2;
436
437 my $node = $NODE{$noderef} || add_node $noderef;
438
439 my $cb = shift;
440
441 unless (ref $cb) {
442 if (@_) {
443 # send a kill info message
444 my (@msg) = ($cb, @_);
445 $cb = sub { snd @msg, @_ };
446 } else {
447 # simply kill other port
448 my $port = $cb;
449 $cb = sub { kil $port, @_ if @_ };
450 }
451 }
452
453 $node->monitor ($port, $cb);
454
455 defined wantarray
456 and AnyEvent::Util::guard { $node->unmonitor ($port, $cb) }
457}
458
459=item $guard = mon_guard $port, $ref, $ref...
460
461Monitors the given C<$port> and keeps the passed references. When the port
462is killed, the references will be freed.
463
464Optionally returns a guard that will stop the monitoring.
465
466This function is useful when you create e.g. timers or other watchers and
467want to free them when the port gets killed:
468
469 $port->rcv (start => sub {
470 my $timer; $timer = mon_guard $port, AE::timer 1, 1, sub {
471 undef $timer if 0.9 < rand;
472 });
473 });
474
475=cut
476
477sub mon_guard {
478 my ($port, @refs) = @_;
479
480 mon $port, sub { 0 && @refs }
481}
482
483=item lnk $port1, $port2
484
485Link two ports. This is simply a shorthand for:
486
487 mon $port1, $port2;
488 mon $port2, $port1;
489
490It means that if either one is killed abnormally, the other one gets
491killed as well.
492
493=item kil $port[, @reason]
494
495Kill the specified port with the given C<@reason>.
496
497If no C<@reason> is specified, then the port is killed "normally" (linked
498ports will not be kileld, or even notified).
499
500Otherwise, linked ports get killed with the same reason (second form of
501C<mon>, see below).
502
503Runtime errors while evaluating C<rcv> callbacks or inside C<psub> blocks
504will be reported as reason C<< die => $@ >>.
505
506Transport/communication errors are reported as C<< transport_error =>
507$message >>.
508
446=back 509=back
447 510
448=head1 FUNCTIONS FOR NODES 511=head1 FUNCTIONS FOR NODES
449 512
450=over 4 513=over 4
451 514
452=item become_public endpoint... 515=item initialise_node $noderef, $seednode, $seednode...
453 516
454Tells the node to become a public node, i.e. reachable from other nodes. 517=item initialise_node "slave/", $master, $master...
455 518
456If no arguments are given, or the first argument is C<undef>, then 519Initialises a node - must be called exactly once before calling other
457AnyEvent::MP tries to bind on port C<4040> on all IP addresses that the 520AnyEvent::MP functions when talking to other nodes is required.
458local nodename resolves to.
459 521
460Otherwise the first argument must be an array-reference with transport 522All arguments are noderefs, which can be either resolved or unresolved.
461endpoints ("ip:port", "hostname:port") or port numbers (in which case the 523
462local nodename is used as hostname). The endpoints are all resolved and 524There are two types of networked nodes, public nodes and slave nodes:
463will become the node reference. 525
526=over 4
527
528=item public nodes
529
530For public nodes, C<$noderef> must either be a (possibly unresolved)
531noderef, in which case it will be resolved, or C<undef> (or missing), in
532which case the noderef will be guessed.
533
534Afterwards, the node will bind itself on all endpoints and try to connect
535to all additional C<$seednodes> that are specified. Seednodes are optional
536and can be used to quickly bootstrap the node into an existing network.
537
538=item slave nodes
539
540When the C<$noderef> is the special string C<slave/>, then the node will
541become a slave node. Slave nodes cannot be contacted from outside and will
542route most of their traffic to the master node that they attach to.
543
544At least one additional noderef is required: The node will try to connect
545to all of them and will become a slave attached to the first node it can
546successfully connect to.
547
548=back
549
550This function will block until all nodes have been resolved and, for slave
551nodes, until it has successfully established a connection to a master
552server.
553
554Example: become a public node listening on the default node.
555
556 initialise_node;
557
558Example: become a public node, and try to contact some well-known master
559servers to become part of the network.
560
561 initialise_node undef, "master1", "master2";
562
563Example: become a public node listening on port C<4041>.
564
565 initialise_node 4041;
566
567Example: become a public node, only visible on localhost port 4044.
568
569 initialise_node "locahost:4044";
570
571Example: become a slave node to any of the specified master servers.
572
573 initialise_node "slave/", "master1", "192.168.13.17", "mp.example.net";
464 574
465=cut 575=cut
466 576
467=back 577=back
468 578
471Nodes understand the following messages sent to them. Many of them take 581Nodes understand the following messages sent to them. Many of them take
472arguments called C<@reply>, which will simply be used to compose a reply 582arguments called C<@reply>, which will simply be used to compose a reply
473message - C<$reply[0]> is the port to reply to, C<$reply[1]> the type and 583message - C<$reply[0]> is the port to reply to, C<$reply[1]> the type and
474the remaining arguments are simply the message data. 584the remaining arguments are simply the message data.
475 585
586While other messages exist, they are not public and subject to change.
587
476=over 4 588=over 4
477 589
478=cut 590=cut
479 591
480=item lookup => $name, @reply 592=item lookup => $name, @reply
510 622
511=back 623=back
512 624
513=head1 AnyEvent::MP vs. Distributed Erlang 625=head1 AnyEvent::MP vs. Distributed Erlang
514 626
515AnyEvent::MP got lots of its ideas from distributed erlang. Despite the 627AnyEvent::MP got lots of its ideas from distributed erlang (erlang node
516similarities (erlang node == aemp node, erlang process == aemp port and so 628== aemp node, erlang process == aemp port), so many of the documents and
629programming techniques employed by erlang apply to AnyEvent::MP. Here is a
630sample:
631
632 http://www.erlang.se/doc/programming_rules.shtml
633 http://erlang.org/doc/getting_started/part_frame.html # chapters 3 and 4
634 http://erlang.org/download/erlang-book-part1.pdf # chapters 5 and 6
635 http://erlang.org/download/armstrong_thesis_2003.pdf # chapters 4 and 5
636
517on), there are also some important differences: 637Despite the similarities, there are also some important differences:
518 638
519=over 4 639=over 4
520 640
521=item * Node references contain the recipe on how to contact them. 641=item * Node references contain the recipe on how to contact them.
522 642
523Erlang relies on special naming and DNS to work everywhere in the 643Erlang relies on special naming and DNS to work everywhere in the
524same way. AEMP relies on each node knowing it's own address(es), with 644same way. AEMP relies on each node knowing it's own address(es), with
525convenience functionality. 645convenience functionality.
526 646
647This means that AEMP requires a less tightly controlled environment at the
648cost of longer node references and a slightly higher management overhead.
649
527=item * Erlang uses processes and a mailbox, AEMP does not queue. 650=item * Erlang uses processes and a mailbox, AEMP does not queue.
528 651
529Erlang uses processes that selctively receive messages, and therefore 652Erlang uses processes that selctively receive messages, and therefore
530needs a queue. AEMP is event based, queuing messages would serve no useful 653needs a queue. AEMP is event based, queuing messages would serve no useful
531purpose. 654purpose.
571authentication and can use TLS. 694authentication and can use TLS.
572 695
573AEMP can use a proven protocol - SSL/TLS - to protect connections and 696AEMP can use a proven protocol - SSL/TLS - to protect connections and
574securely authenticate nodes. 697securely authenticate nodes.
575 698
699=item * The AEMP protocol is optimised for both text-based and binary
700communications.
701
702The AEMP protocol, unlike the erlang protocol, supports both
703language-independent text-only protocols (good for debugging) and binary,
704language-specific serialisers (e.g. Storable).
705
706It has also been carefully designed to be implementable in other languages
707with a minimum of work while gracefully degrading fucntionality to make the
708protocol simple.
709
576=back 710=back
577 711
578=head1 SEE ALSO 712=head1 SEE ALSO
579 713
580L<AnyEvent>. 714L<AnyEvent>.

Diff Legend

Removed lines
+ Added lines
< Changed lines
> Changed lines