… | |
… | |
8 | |
8 | |
9 | $NODE # contains this node's noderef |
9 | $NODE # contains this node's noderef |
10 | NODE # returns this node's noderef |
10 | NODE # returns this node's noderef |
11 | NODE $port # returns the noderef of the port |
11 | NODE $port # returns the noderef of the port |
12 | |
12 | |
|
|
13 | $SELF # receiving/own port id in rcv callbacks |
|
|
14 | |
|
|
15 | # initialise the node so it can send/receive messages |
|
|
16 | initialise_node; # -OR- |
|
|
17 | initialise_node "localhost:4040"; # -OR- |
|
|
18 | initialise_node "slave/", "localhost:4040" |
|
|
19 | |
|
|
20 | # ports are message endpoints |
|
|
21 | |
|
|
22 | # sending messages |
13 | snd $port, type => data...; |
23 | snd $port, type => data...; |
|
|
24 | snd $port, @msg; |
|
|
25 | snd @msg_with_first_element_being_a_port; |
14 | |
26 | |
15 | $SELF # receiving/own port id in rcv callbacks |
27 | # creating/using ports, the simple way |
|
|
28 | my $simple_port = port { my @msg = @_; 0 }; |
16 | |
29 | |
17 | rcv $port, smartmatch => $cb->($port, @msg); |
30 | # creating/using ports, tagged message matching |
18 | |
31 | my $port = port; |
19 | # examples: |
|
|
20 | rcv $port2, ping => sub { snd $_[0], "pong"; 0 }; |
32 | rcv $port, ping => sub { snd $_[0], "pong"; 0 }; |
21 | rcv $port1, pong => sub { warn "pong received\n" }; |
33 | rcv $port, pong => sub { warn "pong received\n"; 0 }; |
22 | snd $port2, ping => $port1; |
|
|
23 | |
34 | |
24 | # more, smarter, matches (_any_ is exported by this module) |
35 | # create a port on another node |
25 | rcv $port, [child_died => $pid] => sub { ... |
36 | my $port = spawn $node, $initfunc, @initdata; |
26 | rcv $port, [_any_, _any_, 3] => sub { .. $_[2] is 3 |
|
|
27 | |
37 | |
28 | # monitoring |
38 | # monitoring |
29 | mon $port, $cb->(@msg) # callback is invoked on death |
39 | mon $port, $cb->(@msg) # callback is invoked on death |
30 | mon $port, $otherport # kill otherport on abnormal death |
40 | mon $port, $otherport # kill otherport on abnormal death |
31 | mon $port, $otherport, @msg # send message on death |
41 | mon $port, $otherport, @msg # send message on death |
32 | |
42 | |
|
|
43 | =head1 CURRENT STATUS |
|
|
44 | |
|
|
45 | AnyEvent::MP - stable API, should work |
|
|
46 | AnyEvent::MP::Intro - outdated |
|
|
47 | AnyEvent::MP::Kernel - WIP |
|
|
48 | AnyEvent::MP::Transport - mostly stable |
|
|
49 | |
|
|
50 | stay tuned. |
|
|
51 | |
33 | =head1 DESCRIPTION |
52 | =head1 DESCRIPTION |
34 | |
53 | |
35 | This module (-family) implements a simple message passing framework. |
54 | This module (-family) implements a simple message passing framework. |
36 | |
55 | |
37 | Despite its simplicity, you can securely message other processes running |
56 | Despite its simplicity, you can securely message other processes running |
… | |
… | |
40 | For an introduction to this module family, see the L<AnyEvent::MP::Intro> |
59 | For an introduction to this module family, see the L<AnyEvent::MP::Intro> |
41 | manual page. |
60 | manual page. |
42 | |
61 | |
43 | At the moment, this module family is severly broken and underdocumented, |
62 | At the moment, this module family is severly broken and underdocumented, |
44 | so do not use. This was uploaded mainly to reserve the CPAN namespace - |
63 | so do not use. This was uploaded mainly to reserve the CPAN namespace - |
45 | stay tuned! The basic API should be finished, however. |
64 | stay tuned! |
46 | |
65 | |
47 | =head1 CONCEPTS |
66 | =head1 CONCEPTS |
48 | |
67 | |
49 | =over 4 |
68 | =over 4 |
50 | |
69 | |
51 | =item port |
70 | =item port |
52 | |
71 | |
53 | A port is something you can send messages to (with the C<snd> function). |
72 | A port is something you can send messages to (with the C<snd> function). |
54 | |
73 | |
55 | Some ports allow you to register C<rcv> handlers that can match specific |
74 | Ports allow you to register C<rcv> handlers that can match all or just |
56 | messages. All C<rcv> handlers will receive messages they match, messages |
75 | some messages. Messages will not be queued. |
57 | will not be queued. |
|
|
58 | |
76 | |
59 | =item port id - C<noderef#portname> |
77 | =item port id - C<noderef#portname> |
60 | |
78 | |
61 | A port id is normaly the concatenation of a noderef, a hash-mark (C<#>) as |
79 | A port ID is the concatenation of a noderef, a hash-mark (C<#>) as |
62 | separator, and a port name (a printable string of unspecified format). An |
80 | separator, and a port name (a printable string of unspecified format). An |
63 | exception is the the node port, whose ID is identical to its node |
81 | exception is the the node port, whose ID is identical to its node |
64 | reference. |
82 | reference. |
65 | |
83 | |
66 | =item node |
84 | =item node |
67 | |
85 | |
68 | A node is a single process containing at least one port - the node |
86 | A node is a single process containing at least one port - the node port, |
69 | port. You can send messages to node ports to find existing ports or to |
87 | which provides nodes to manage each other remotely, and to create new |
70 | create new ports, among other things. |
88 | ports. |
71 | |
89 | |
72 | Nodes are either private (single-process only), slaves (connected to a |
90 | Nodes are either private (single-process only), slaves (connected to a |
73 | master node only) or public nodes (connectable from unrelated nodes). |
91 | master node only) or public nodes (connectable from unrelated nodes). |
74 | |
92 | |
75 | =item noderef - C<host:port,host:port...>, C<id@noderef>, C<id> |
93 | =item noderef - C<host:port,host:port...>, C<id@noderef>, C<id> |
… | |
… | |
95 | |
113 | |
96 | =cut |
114 | =cut |
97 | |
115 | |
98 | package AnyEvent::MP; |
116 | package AnyEvent::MP; |
99 | |
117 | |
100 | use AnyEvent::MP::Base; |
118 | use AnyEvent::MP::Kernel; |
101 | |
119 | |
102 | use common::sense; |
120 | use common::sense; |
103 | |
121 | |
104 | use Carp (); |
122 | use Carp (); |
105 | |
123 | |
106 | use AE (); |
124 | use AE (); |
107 | |
125 | |
108 | use base "Exporter"; |
126 | use base "Exporter"; |
109 | |
127 | |
110 | our $VERSION = '0.1'; |
128 | our $VERSION = $AnyEvent::MP::Kernel::VERSION; |
|
|
129 | |
111 | our @EXPORT = qw( |
130 | our @EXPORT = qw( |
112 | NODE $NODE *SELF node_of _any_ |
131 | NODE $NODE *SELF node_of _any_ |
113 | resolve_node initialise_node |
132 | resolve_node initialise_node |
114 | snd rcv mon kil reg psub |
133 | snd rcv mon kil reg psub spawn |
115 | port |
134 | port |
116 | ); |
135 | ); |
117 | |
136 | |
118 | our $SELF; |
137 | our $SELF; |
119 | |
138 | |
… | |
… | |
123 | kil $SELF, die => $msg; |
142 | kil $SELF, die => $msg; |
124 | } |
143 | } |
125 | |
144 | |
126 | =item $thisnode = NODE / $NODE |
145 | =item $thisnode = NODE / $NODE |
127 | |
146 | |
128 | The C<NODE> function returns, and the C<$NODE> variable contains |
147 | The C<NODE> function returns, and the C<$NODE> variable contains the |
129 | the noderef of the local node. The value is initialised by a call |
148 | noderef of the local node. The value is initialised by a call to |
130 | to C<become_public> or C<become_slave>, after which all local port |
149 | C<initialise_node>. |
131 | identifiers become invalid. |
|
|
132 | |
150 | |
133 | =item $noderef = node_of $port |
151 | =item $noderef = node_of $port |
134 | |
152 | |
135 | Extracts and returns the noderef from a portid or a noderef. |
153 | Extracts and returns the noderef from a port ID or a noderef. |
136 | |
154 | |
137 | =item initialise_node $noderef, $seednode, $seednode... |
155 | =item initialise_node $noderef, $seednode, $seednode... |
138 | |
156 | |
139 | =item initialise_node "slave/", $master, $master... |
157 | =item initialise_node "slave/", $master, $master... |
140 | |
158 | |
… | |
… | |
143 | it should know the noderefs of some other nodes in the network. |
161 | it should know the noderefs of some other nodes in the network. |
144 | |
162 | |
145 | This function initialises a node - it must be called exactly once (or |
163 | This function initialises a node - it must be called exactly once (or |
146 | never) before calling other AnyEvent::MP functions. |
164 | never) before calling other AnyEvent::MP functions. |
147 | |
165 | |
148 | All arguments are noderefs, which can be either resolved or unresolved. |
166 | All arguments (optionally except for the first) are noderefs, which can be |
|
|
167 | either resolved or unresolved. |
|
|
168 | |
|
|
169 | The first argument will be looked up in the configuration database first |
|
|
170 | (if it is C<undef> then the current nodename will be used instead) to find |
|
|
171 | the relevant configuration profile (see L<aemp>). If none is found then |
|
|
172 | the default configuration is used. The configuration supplies additional |
|
|
173 | seed/master nodes and can override the actual noderef. |
149 | |
174 | |
150 | There are two types of networked nodes, public nodes and slave nodes: |
175 | There are two types of networked nodes, public nodes and slave nodes: |
151 | |
176 | |
152 | =over 4 |
177 | =over 4 |
153 | |
178 | |
154 | =item public nodes |
179 | =item public nodes |
155 | |
180 | |
156 | For public nodes, C<$noderef> must either be a (possibly unresolved) |
181 | For public nodes, C<$noderef> (supplied either directly to |
157 | noderef, in which case it will be resolved, or C<undef> (or missing), in |
182 | C<initialise_node> or indirectly via a profile or the nodename) must be a |
158 | which case the noderef will be guessed. |
183 | noderef (possibly unresolved, in which case it will be resolved). |
159 | |
184 | |
160 | Afterwards, the node will bind itself on all endpoints and try to connect |
185 | After resolving, the node will bind itself on all endpoints and try to |
161 | to all additional C<$seednodes> that are specified. Seednodes are optional |
186 | connect to all additional C<$seednodes> that are specified. Seednodes are |
162 | and can be used to quickly bootstrap the node into an existing network. |
187 | optional and can be used to quickly bootstrap the node into an existing |
|
|
188 | network. |
163 | |
189 | |
164 | =item slave nodes |
190 | =item slave nodes |
165 | |
191 | |
166 | When the C<$noderef> is the special string C<slave/>, then the node will |
192 | When the C<$noderef> (either as given or overriden by the config file) |
|
|
193 | is the special string C<slave/>, then the node will become a slave |
167 | become a slave node. Slave nodes cannot be contacted from outside and will |
194 | node. Slave nodes cannot be contacted from outside and will route most of |
168 | route most of their traffic to the master node that they attach to. |
195 | their traffic to the master node that they attach to. |
169 | |
196 | |
170 | At least one additional noderef is required: The node will try to connect |
197 | At least one additional noderef is required (either by specifying it |
171 | to all of them and will become a slave attached to the first node it can |
198 | directly or because it is part of the configuration profile): The node |
172 | successfully connect to. |
199 | will try to connect to all of them and will become a slave attached to the |
|
|
200 | first node it can successfully connect to. |
173 | |
201 | |
174 | =back |
202 | =back |
175 | |
203 | |
176 | This function will block until all nodes have been resolved and, for slave |
204 | This function will block until all nodes have been resolved and, for slave |
177 | nodes, until it has successfully established a connection to a master |
205 | nodes, until it has successfully established a connection to a master |
178 | server. |
206 | server. |
179 | |
207 | |
180 | Example: become a public node listening on the default node. |
208 | Example: become a public node listening on the guessed noderef, or the one |
|
|
209 | specified via C<aemp> for the current node. This should be the most common |
|
|
210 | form of invocation for "daemon"-type nodes. |
181 | |
211 | |
182 | initialise_node; |
212 | initialise_node; |
|
|
213 | |
|
|
214 | Example: become a slave node to any of the the seednodes specified via |
|
|
215 | C<aemp>. This form is often used for commandline clients. |
|
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216 | |
|
|
217 | initialise_node "slave/"; |
|
|
218 | |
|
|
219 | Example: become a slave node to any of the specified master servers. This |
|
|
220 | form is also often used for commandline clients. |
|
|
221 | |
|
|
222 | initialise_node "slave/", "master1", "192.168.13.17", "mp.example.net"; |
183 | |
223 | |
184 | Example: become a public node, and try to contact some well-known master |
224 | Example: become a public node, and try to contact some well-known master |
185 | servers to become part of the network. |
225 | servers to become part of the network. |
186 | |
226 | |
187 | initialise_node undef, "master1", "master2"; |
227 | initialise_node undef, "master1", "master2"; |
… | |
… | |
190 | |
230 | |
191 | initialise_node 4041; |
231 | initialise_node 4041; |
192 | |
232 | |
193 | Example: become a public node, only visible on localhost port 4044. |
233 | Example: become a public node, only visible on localhost port 4044. |
194 | |
234 | |
195 | initialise_node "locahost:4044"; |
235 | initialise_node "localhost:4044"; |
196 | |
|
|
197 | Example: become a slave node to any of the specified master servers. |
|
|
198 | |
|
|
199 | initialise_node "slave/", "master1", "192.168.13.17", "mp.example.net"; |
|
|
200 | |
236 | |
201 | =item $cv = resolve_node $noderef |
237 | =item $cv = resolve_node $noderef |
202 | |
238 | |
203 | Takes an unresolved node reference that may contain hostnames and |
239 | Takes an unresolved node reference that may contain hostnames and |
204 | abbreviated IDs, resolves all of them and returns a resolved node |
240 | abbreviated IDs, resolves all of them and returns a resolved node |
… | |
… | |
241 | =item snd $port, type => @data |
277 | =item snd $port, type => @data |
242 | |
278 | |
243 | =item snd $port, @msg |
279 | =item snd $port, @msg |
244 | |
280 | |
245 | Send the given message to the given port ID, which can identify either |
281 | Send the given message to the given port ID, which can identify either |
246 | a local or a remote port, and can be either a string or soemthignt hat |
282 | a local or a remote port, and must be a port ID. |
247 | stringifies a sa port ID (such as a port object :). |
|
|
248 | |
283 | |
249 | While the message can be about anything, it is highly recommended to use a |
284 | While the message can be about anything, it is highly recommended to use a |
250 | string as first element (a portid, or some word that indicates a request |
285 | string as first element (a port ID, or some word that indicates a request |
251 | type etc.). |
286 | type etc.). |
252 | |
287 | |
253 | The message data effectively becomes read-only after a call to this |
288 | The message data effectively becomes read-only after a call to this |
254 | function: modifying any argument is not allowed and can cause many |
289 | function: modifying any argument is not allowed and can cause many |
255 | problems. |
290 | problems. |
… | |
… | |
260 | that Storable can serialise and deserialise is allowed, and for the local |
295 | that Storable can serialise and deserialise is allowed, and for the local |
261 | node, anything can be passed. |
296 | node, anything can be passed. |
262 | |
297 | |
263 | =item $local_port = port |
298 | =item $local_port = port |
264 | |
299 | |
265 | Create a new local port object that can be used either as a pattern |
300 | Create a new local port object and returns its port ID. Initially it has |
266 | matching port ("full port") or a single-callback port ("miniport"), |
301 | no callbacks set and will throw an error when it receives messages. |
267 | depending on how C<rcv> callbacks are bound to the object. |
|
|
268 | |
302 | |
269 | =item $port = port { my @msg = @_; $finished } |
303 | =item $local_port = port { my @msg = @_ } |
270 | |
304 | |
271 | Creates a "miniport", that is, a very lightweight port without any pattern |
305 | Creates a new local port, and returns its ID. Semantically the same as |
272 | matching behind it, and returns its ID. Semantically the same as creating |
|
|
273 | a port and calling C<rcv $port, $callback> on it. |
306 | creating a port and calling C<rcv $port, $callback> on it. |
274 | |
307 | |
275 | The block will be called for every message received on the port. When the |
308 | The block will be called for every message received on the port, with the |
276 | callback returns a true value its job is considered "done" and the port |
309 | global variable C<$SELF> set to the port ID. Runtime errors will cause the |
277 | will be destroyed. Otherwise it will stay alive. |
310 | port to be C<kil>ed. The message will be passed as-is, no extra argument |
|
|
311 | (i.e. no port ID) will be passed to the callback. |
278 | |
312 | |
279 | The message will be passed as-is, no extra argument (i.e. no port id) will |
313 | If you want to stop/destroy the port, simply C<kil> it: |
280 | be passed to the callback. |
|
|
281 | |
314 | |
282 | If you need the local port id in the callback, this works nicely: |
315 | my $port = port { |
283 | |
316 | my @msg = @_; |
284 | my $port; $port = port { |
317 | ... |
285 | snd $otherport, reply => $port; |
318 | kil $SELF; |
286 | }; |
319 | }; |
287 | |
320 | |
288 | =cut |
321 | =cut |
289 | |
322 | |
290 | sub rcv($@); |
323 | sub rcv($@); |
|
|
324 | |
|
|
325 | sub _kilme { |
|
|
326 | die "received message on port without callback"; |
|
|
327 | } |
291 | |
328 | |
292 | sub port(;&) { |
329 | sub port(;&) { |
293 | my $id = "$UNIQ." . $ID++; |
330 | my $id = "$UNIQ." . $ID++; |
294 | my $port = "$NODE#$id"; |
331 | my $port = "$NODE#$id"; |
295 | |
332 | |
296 | if (@_) { |
333 | rcv $port, shift || \&_kilme; |
297 | rcv $port, shift; |
|
|
298 | } else { |
|
|
299 | $PORT{$id} = sub { }; # nop |
|
|
300 | } |
|
|
301 | |
334 | |
302 | $port |
335 | $port |
303 | } |
336 | } |
304 | |
337 | |
305 | =item reg $port, $name |
|
|
306 | |
|
|
307 | =item reg $name |
|
|
308 | |
|
|
309 | Registers the given port (or C<$SELF><<< if missing) under the name |
|
|
310 | C<$name>. If the name already exists it is replaced. |
|
|
311 | |
|
|
312 | A port can only be registered under one well known name. |
|
|
313 | |
|
|
314 | A port automatically becomes unregistered when it is killed. |
|
|
315 | |
|
|
316 | =cut |
|
|
317 | |
|
|
318 | sub reg(@) { |
|
|
319 | my $port = @_ > 1 ? shift : $SELF || Carp::croak 'reg: called with one argument only, but $SELF not set,'; |
|
|
320 | |
|
|
321 | $REG{$_[0]} = $port; |
|
|
322 | } |
|
|
323 | |
|
|
324 | =item rcv $port, $callback->(@msg) |
338 | =item rcv $local_port, $callback->(@msg) |
325 | |
339 | |
326 | Replaces the callback on the specified miniport (after converting it to |
340 | Replaces the default callback on the specified port. There is no way to |
327 | one if required). |
341 | remove the default callback: use C<sub { }> to disable it, or better |
328 | |
342 | C<kil> the port when it is no longer needed. |
329 | =item rcv $port, tagstring => $callback->(@msg), ... |
|
|
330 | |
|
|
331 | =item rcv $port, $smartmatch => $callback->(@msg), ... |
|
|
332 | |
|
|
333 | =item rcv $port, [$smartmatch...] => $callback->(@msg), ... |
|
|
334 | |
|
|
335 | Register callbacks to be called on matching messages on the given full |
|
|
336 | port (after converting it to one if required) and return the port. |
|
|
337 | |
|
|
338 | The callback has to return a true value when its work is done, after |
|
|
339 | which is will be removed, or a false value in which case it will stay |
|
|
340 | registered. |
|
|
341 | |
343 | |
342 | The global C<$SELF> (exported by this module) contains C<$port> while |
344 | The global C<$SELF> (exported by this module) contains C<$port> while |
343 | executing the callback. |
345 | executing the callback. Runtime errors during callback execution will |
|
|
346 | result in the port being C<kil>ed. |
344 | |
347 | |
345 | Runtime errors wdurign callback execution will result in the port being |
348 | The default callback received all messages not matched by a more specific |
346 | C<kil>ed. |
349 | C<tag> match. |
347 | |
350 | |
348 | If the match is an array reference, then it will be matched against the |
351 | =item rcv $local_port, tag => $callback->(@msg_without_tag), ... |
349 | first elements of the message, otherwise only the first element is being |
|
|
350 | matched. |
|
|
351 | |
352 | |
352 | Any element in the match that is specified as C<_any_> (a function |
353 | Register (or replace) callbacks to be called on messages starting with the |
353 | exported by this module) matches any single element of the message. |
354 | given tag on the given port (and return the port), or unregister it (when |
|
|
355 | C<$callback> is C<$undef> or missing). There can only be one callback |
|
|
356 | registered for each tag. |
354 | |
357 | |
355 | While not required, it is highly recommended that the first matching |
358 | The original message will be passed to the callback, after the first |
356 | element is a string identifying the message. The one-string-only match is |
359 | element (the tag) has been removed. The callback will use the same |
357 | also the most efficient match (by far). |
360 | environment as the default callback (see above). |
358 | |
361 | |
359 | Example: create a port and bind receivers on it in one go. |
362 | Example: create a port and bind receivers on it in one go. |
360 | |
363 | |
361 | my $port = rcv port, |
364 | my $port = rcv port, |
362 | msg1 => sub { ...; 0 }, |
365 | msg1 => sub { ... }, |
363 | msg2 => sub { ...; 0 }, |
366 | msg2 => sub { ... }, |
364 | ; |
367 | ; |
365 | |
368 | |
366 | Example: create a port, bind receivers and send it in a message elsewhere |
369 | Example: create a port, bind receivers and send it in a message elsewhere |
367 | in one go: |
370 | in one go: |
368 | |
371 | |
369 | snd $otherport, reply => |
372 | snd $otherport, reply => |
370 | rcv port, |
373 | rcv port, |
371 | msg1 => sub { ...; 0 }, |
374 | msg1 => sub { ... }, |
372 | ... |
375 | ... |
373 | ; |
376 | ; |
|
|
377 | |
|
|
378 | Example: temporarily register a rcv callback for a tag matching some port |
|
|
379 | (e.g. for a rpc reply) and unregister it after a message was received. |
|
|
380 | |
|
|
381 | rcv $port, $otherport => sub { |
|
|
382 | my @reply = @_; |
|
|
383 | |
|
|
384 | rcv $SELF, $otherport; |
|
|
385 | }; |
374 | |
386 | |
375 | =cut |
387 | =cut |
376 | |
388 | |
377 | sub rcv($@) { |
389 | sub rcv($@) { |
378 | my $port = shift; |
390 | my $port = shift; |
379 | my ($noderef, $portid) = split /#/, $port, 2; |
391 | my ($noderef, $portid) = split /#/, $port, 2; |
380 | |
392 | |
381 | ($NODE{$noderef} || add_node $noderef) == $NODE{""} |
393 | ($NODE{$noderef} || add_node $noderef) == $NODE{""} |
382 | or Carp::croak "$port: rcv can only be called on local ports, caught"; |
394 | or Carp::croak "$port: rcv can only be called on local ports, caught"; |
383 | |
395 | |
384 | if (@_ == 1) { |
396 | while (@_) { |
|
|
397 | if (ref $_[0]) { |
|
|
398 | if (my $self = $PORT_DATA{$portid}) { |
|
|
399 | "AnyEvent::MP::Port" eq ref $self |
|
|
400 | or Carp::croak "$port: rcv can only be called on message matching ports, caught"; |
|
|
401 | |
|
|
402 | $self->[2] = shift; |
|
|
403 | } else { |
385 | my $cb = shift; |
404 | my $cb = shift; |
386 | delete $PORT_DATA{$portid}; |
|
|
387 | $PORT{$portid} = sub { |
405 | $PORT{$portid} = sub { |
388 | local $SELF = $port; |
406 | local $SELF = $port; |
389 | eval { |
407 | eval { &$cb }; _self_die if $@; |
390 | &$cb |
408 | }; |
391 | and kil $port; |
|
|
392 | }; |
409 | } |
393 | _self_die if $@; |
410 | } elsif (defined $_[0]) { |
394 | }; |
|
|
395 | } else { |
|
|
396 | my $self = $PORT_DATA{$portid} ||= do { |
411 | my $self = $PORT_DATA{$portid} ||= do { |
397 | my $self = bless { |
412 | my $self = bless [$PORT{$port} || sub { }, { }, $port], "AnyEvent::MP::Port"; |
398 | id => $port, |
|
|
399 | }, "AnyEvent::MP::Port"; |
|
|
400 | |
413 | |
401 | $PORT{$portid} = sub { |
414 | $PORT{$portid} = sub { |
402 | local $SELF = $port; |
415 | local $SELF = $port; |
403 | |
416 | |
404 | eval { |
|
|
405 | for (@{ $self->{rc0}{$_[0]} }) { |
417 | if (my $cb = $self->[1]{$_[0]}) { |
406 | $_ && &{$_->[0]} |
418 | shift; |
407 | && undef $_; |
419 | eval { &$cb }; _self_die if $@; |
408 | } |
420 | } else { |
409 | |
|
|
410 | for (@{ $self->{rcv}{$_[0]} }) { |
|
|
411 | $_ && [@_[1 .. @{$_->[1]}]] ~~ $_->[1] |
|
|
412 | && &{$_->[0]} |
421 | &{ $self->[0] }; |
413 | && undef $_; |
|
|
414 | } |
|
|
415 | |
|
|
416 | for (@{ $self->{any} }) { |
|
|
417 | $_ && [@_[0 .. $#{$_->[1]}]] ~~ $_->[1] |
|
|
418 | && &{$_->[0]} |
|
|
419 | && undef $_; |
|
|
420 | } |
422 | } |
421 | }; |
423 | }; |
422 | _self_die if $@; |
424 | |
|
|
425 | $self |
423 | }; |
426 | }; |
424 | |
427 | |
425 | $self |
|
|
426 | }; |
|
|
427 | |
|
|
428 | "AnyEvent::MP::Port" eq ref $self |
428 | "AnyEvent::MP::Port" eq ref $self |
429 | or Carp::croak "$port: rcv can only be called on message matching ports, caught"; |
429 | or Carp::croak "$port: rcv can only be called on message matching ports, caught"; |
430 | |
430 | |
431 | while (@_) { |
|
|
432 | my ($match, $cb) = splice @_, 0, 2; |
431 | my ($tag, $cb) = splice @_, 0, 2; |
433 | |
432 | |
434 | if (!ref $match) { |
433 | if (defined $cb) { |
435 | push @{ $self->{rc0}{$match} }, [$cb]; |
434 | $self->[1]{$tag} = $cb; |
436 | } elsif (("ARRAY" eq ref $match && !ref $match->[0])) { |
|
|
437 | my ($type, @match) = @$match; |
|
|
438 | @match |
|
|
439 | ? push @{ $self->{rcv}{$match->[0]} }, [$cb, \@match] |
|
|
440 | : push @{ $self->{rc0}{$match->[0]} }, [$cb]; |
|
|
441 | } else { |
435 | } else { |
442 | push @{ $self->{any} }, [$cb, $match]; |
436 | delete $self->[1]{$tag}; |
443 | } |
437 | } |
444 | } |
438 | } |
445 | } |
439 | } |
446 | |
440 | |
447 | $port |
441 | $port |
… | |
… | |
491 | |
485 | |
492 | =item $guard = mon $port |
486 | =item $guard = mon $port |
493 | |
487 | |
494 | =item $guard = mon $port, $rcvport, @msg |
488 | =item $guard = mon $port, $rcvport, @msg |
495 | |
489 | |
496 | Monitor the given port and do something when the port is killed, and |
490 | Monitor the given port and do something when the port is killed or |
497 | optionally return a guard that can be used to stop monitoring again. |
491 | messages to it were lost, and optionally return a guard that can be used |
|
|
492 | to stop monitoring again. |
|
|
493 | |
|
|
494 | C<mon> effectively guarantees that, in the absence of hardware failures, |
|
|
495 | that after starting the monitor, either all messages sent to the port |
|
|
496 | will arrive, or the monitoring action will be invoked after possible |
|
|
497 | message loss has been detected. No messages will be lost "in between" |
|
|
498 | (after the first lost message no further messages will be received by the |
|
|
499 | port). After the monitoring action was invoked, further messages might get |
|
|
500 | delivered again. |
498 | |
501 | |
499 | In the first form (callback), the callback is simply called with any |
502 | In the first form (callback), the callback is simply called with any |
500 | number of C<@reason> elements (no @reason means that the port was deleted |
503 | number of C<@reason> elements (no @reason means that the port was deleted |
501 | "normally"). Note also that I<< the callback B<must> never die >>, so use |
504 | "normally"). Note also that I<< the callback B<must> never die >>, so use |
502 | C<eval> if unsure. |
505 | C<eval> if unsure. |
503 | |
506 | |
504 | In the second form (another port given), the other port (C<$rcvport) |
507 | In the second form (another port given), the other port (C<$rcvport>) |
505 | will be C<kil>'ed with C<@reason>, iff a @reason was specified, i.e. on |
508 | will be C<kil>'ed with C<@reason>, iff a @reason was specified, i.e. on |
506 | "normal" kils nothing happens, while under all other conditions, the other |
509 | "normal" kils nothing happens, while under all other conditions, the other |
507 | port is killed with the same reason. |
510 | port is killed with the same reason. |
508 | |
511 | |
509 | The third form (kill self) is the same as the second form, except that |
512 | The third form (kill self) is the same as the second form, except that |
… | |
… | |
536 | sub mon { |
539 | sub mon { |
537 | my ($noderef, $port) = split /#/, shift, 2; |
540 | my ($noderef, $port) = split /#/, shift, 2; |
538 | |
541 | |
539 | my $node = $NODE{$noderef} || add_node $noderef; |
542 | my $node = $NODE{$noderef} || add_node $noderef; |
540 | |
543 | |
541 | my $cb = @_ ? $_[0] : $SELF || Carp::croak 'mon: called with one argument only, but $SELF not set,'; |
544 | my $cb = @_ ? shift : $SELF || Carp::croak 'mon: called with one argument only, but $SELF not set,'; |
542 | |
545 | |
543 | unless (ref $cb) { |
546 | unless (ref $cb) { |
544 | if (@_) { |
547 | if (@_) { |
545 | # send a kill info message |
548 | # send a kill info message |
546 | my (@msg) = @_; |
549 | my (@msg) = ($cb, @_); |
547 | $cb = sub { snd @msg, @_ }; |
550 | $cb = sub { snd @msg, @_ }; |
548 | } else { |
551 | } else { |
549 | # simply kill other port |
552 | # simply kill other port |
550 | my $port = $cb; |
553 | my $port = $cb; |
551 | $cb = sub { kil $port, @_ if @_ }; |
554 | $cb = sub { kil $port, @_ if @_ }; |
… | |
… | |
598 | will be reported as reason C<< die => $@ >>. |
601 | will be reported as reason C<< die => $@ >>. |
599 | |
602 | |
600 | Transport/communication errors are reported as C<< transport_error => |
603 | Transport/communication errors are reported as C<< transport_error => |
601 | $message >>. |
604 | $message >>. |
602 | |
605 | |
|
|
606 | =cut |
|
|
607 | |
|
|
608 | =item $port = spawn $node, $initfunc[, @initdata] |
|
|
609 | |
|
|
610 | Creates a port on the node C<$node> (which can also be a port ID, in which |
|
|
611 | case it's the node where that port resides). |
|
|
612 | |
|
|
613 | The port ID of the newly created port is return immediately, and it is |
|
|
614 | permissible to immediately start sending messages or monitor the port. |
|
|
615 | |
|
|
616 | After the port has been created, the init function is |
|
|
617 | called. This function must be a fully-qualified function name |
|
|
618 | (e.g. C<MyApp::Chat::Server::init>). To specify a function in the main |
|
|
619 | program, use C<::name>. |
|
|
620 | |
|
|
621 | If the function doesn't exist, then the node tries to C<require> |
|
|
622 | the package, then the package above the package and so on (e.g. |
|
|
623 | C<MyApp::Chat::Server>, C<MyApp::Chat>, C<MyApp>) until the function |
|
|
624 | exists or it runs out of package names. |
|
|
625 | |
|
|
626 | The init function is then called with the newly-created port as context |
|
|
627 | object (C<$SELF>) and the C<@initdata> values as arguments. |
|
|
628 | |
|
|
629 | A common idiom is to pass your own port, monitor the spawned port, and |
|
|
630 | in the init function, monitor the original port. This two-way monitoring |
|
|
631 | ensures that both ports get cleaned up when there is a problem. |
|
|
632 | |
|
|
633 | Example: spawn a chat server port on C<$othernode>. |
|
|
634 | |
|
|
635 | # this node, executed from within a port context: |
|
|
636 | my $server = spawn $othernode, "MyApp::Chat::Server::connect", $SELF; |
|
|
637 | mon $server; |
|
|
638 | |
|
|
639 | # init function on C<$othernode> |
|
|
640 | sub connect { |
|
|
641 | my ($srcport) = @_; |
|
|
642 | |
|
|
643 | mon $srcport; |
|
|
644 | |
|
|
645 | rcv $SELF, sub { |
|
|
646 | ... |
|
|
647 | }; |
|
|
648 | } |
|
|
649 | |
|
|
650 | =cut |
|
|
651 | |
|
|
652 | sub _spawn { |
|
|
653 | my $port = shift; |
|
|
654 | my $init = shift; |
|
|
655 | |
|
|
656 | local $SELF = "$NODE#$port"; |
|
|
657 | eval { |
|
|
658 | &{ load_func $init } |
|
|
659 | }; |
|
|
660 | _self_die if $@; |
|
|
661 | } |
|
|
662 | |
|
|
663 | sub spawn(@) { |
|
|
664 | my ($noderef, undef) = split /#/, shift, 2; |
|
|
665 | |
|
|
666 | my $id = "$RUNIQ." . $ID++; |
|
|
667 | |
|
|
668 | $_[0] =~ /::/ |
|
|
669 | or Carp::croak "spawn init function must be a fully-qualified name, caught"; |
|
|
670 | |
|
|
671 | ($NODE{$noderef} || add_node $noderef) |
|
|
672 | ->send (["", "AnyEvent::MP::_spawn" => $id, @_]); |
|
|
673 | |
|
|
674 | "$noderef#$id" |
|
|
675 | } |
|
|
676 | |
603 | =back |
677 | =back |
604 | |
678 | |
605 | =head1 NODE MESSAGES |
679 | =head1 NODE MESSAGES |
606 | |
680 | |
607 | Nodes understand the following messages sent to them. Many of them take |
681 | Nodes understand the following messages sent to them. Many of them take |
… | |
… | |
671 | convenience functionality. |
745 | convenience functionality. |
672 | |
746 | |
673 | This means that AEMP requires a less tightly controlled environment at the |
747 | This means that AEMP requires a less tightly controlled environment at the |
674 | cost of longer node references and a slightly higher management overhead. |
748 | cost of longer node references and a slightly higher management overhead. |
675 | |
749 | |
|
|
750 | =item * Erlang has a "remote ports are like local ports" philosophy, AEMP |
|
|
751 | uses "local ports are like remote ports". |
|
|
752 | |
|
|
753 | The failure modes for local ports are quite different (runtime errors |
|
|
754 | only) then for remote ports - when a local port dies, you I<know> it dies, |
|
|
755 | when a connection to another node dies, you know nothing about the other |
|
|
756 | port. |
|
|
757 | |
|
|
758 | Erlang pretends remote ports are as reliable as local ports, even when |
|
|
759 | they are not. |
|
|
760 | |
|
|
761 | AEMP encourages a "treat remote ports differently" philosophy, with local |
|
|
762 | ports being the special case/exception, where transport errors cannot |
|
|
763 | occur. |
|
|
764 | |
676 | =item * Erlang uses processes and a mailbox, AEMP does not queue. |
765 | =item * Erlang uses processes and a mailbox, AEMP does not queue. |
677 | |
766 | |
678 | Erlang uses processes that selctively receive messages, and therefore |
767 | Erlang uses processes that selectively receive messages, and therefore |
679 | needs a queue. AEMP is event based, queuing messages would serve no useful |
768 | needs a queue. AEMP is event based, queuing messages would serve no |
680 | purpose. |
769 | useful purpose. For the same reason the pattern-matching abilities of |
|
|
770 | AnyEvent::MP are more limited, as there is little need to be able to |
|
|
771 | filter messages without dequeing them. |
681 | |
772 | |
682 | (But see L<Coro::MP> for a more Erlang-like process model on top of AEMP). |
773 | (But see L<Coro::MP> for a more Erlang-like process model on top of AEMP). |
683 | |
774 | |
684 | =item * Erlang sends are synchronous, AEMP sends are asynchronous. |
775 | =item * Erlang sends are synchronous, AEMP sends are asynchronous. |
685 | |
776 | |
686 | Sending messages in Erlang is synchronous and blocks the process. AEMP |
777 | Sending messages in Erlang is synchronous and blocks the process (and |
687 | sends are immediate, connection establishment is handled in the |
778 | so does not need a queue that can overflow). AEMP sends are immediate, |
688 | background. |
779 | connection establishment is handled in the background. |
689 | |
780 | |
690 | =item * Erlang can silently lose messages, AEMP cannot. |
781 | =item * Erlang suffers from silent message loss, AEMP does not. |
691 | |
782 | |
692 | Erlang makes few guarantees on messages delivery - messages can get lost |
783 | Erlang makes few guarantees on messages delivery - messages can get lost |
693 | without any of the processes realising it (i.e. you send messages a, b, |
784 | without any of the processes realising it (i.e. you send messages a, b, |
694 | and c, and the other side only receives messages a and c). |
785 | and c, and the other side only receives messages a and c). |
695 | |
786 | |
… | |
… | |
707 | eventually be killed - it cannot happen that a node detects a port as dead |
798 | eventually be killed - it cannot happen that a node detects a port as dead |
708 | and then later sends messages to it, finding it is still alive. |
799 | and then later sends messages to it, finding it is still alive. |
709 | |
800 | |
710 | =item * Erlang can send messages to the wrong port, AEMP does not. |
801 | =item * Erlang can send messages to the wrong port, AEMP does not. |
711 | |
802 | |
712 | In Erlang it is quite possible that a node that restarts reuses a process |
803 | In Erlang it is quite likely that a node that restarts reuses a process ID |
713 | ID known to other nodes for a completely different process, causing |
804 | known to other nodes for a completely different process, causing messages |
714 | messages destined for that process to end up in an unrelated process. |
805 | destined for that process to end up in an unrelated process. |
715 | |
806 | |
716 | AEMP never reuses port IDs, so old messages or old port IDs floating |
807 | AEMP never reuses port IDs, so old messages or old port IDs floating |
717 | around in the network will not be sent to an unrelated port. |
808 | around in the network will not be sent to an unrelated port. |
718 | |
809 | |
719 | =item * Erlang uses unprotected connections, AEMP uses secure |
810 | =item * Erlang uses unprotected connections, AEMP uses secure |
… | |
… | |
755 | This also saves round-trips and avoids sending messages to the wrong port |
846 | This also saves round-trips and avoids sending messages to the wrong port |
756 | (hard to do in Erlang). |
847 | (hard to do in Erlang). |
757 | |
848 | |
758 | =back |
849 | =back |
759 | |
850 | |
|
|
851 | =head1 RATIONALE |
|
|
852 | |
|
|
853 | =over 4 |
|
|
854 | |
|
|
855 | =item Why strings for ports and noderefs, why not objects? |
|
|
856 | |
|
|
857 | We considered "objects", but found that the actual number of methods |
|
|
858 | thatc an be called are very low. Since port IDs and noderefs travel over |
|
|
859 | the network frequently, the serialising/deserialising would add lots of |
|
|
860 | overhead, as well as having to keep a proxy object. |
|
|
861 | |
|
|
862 | Strings can easily be printed, easily serialised etc. and need no special |
|
|
863 | procedures to be "valid". |
|
|
864 | |
|
|
865 | And a a miniport consists of a single closure stored in a global hash - it |
|
|
866 | can't become much cheaper. |
|
|
867 | |
|
|
868 | =item Why favour JSON, why not real serialising format such as Storable? |
|
|
869 | |
|
|
870 | In fact, any AnyEvent::MP node will happily accept Storable as framing |
|
|
871 | format, but currently there is no way to make a node use Storable by |
|
|
872 | default. |
|
|
873 | |
|
|
874 | The default framing protocol is JSON because a) JSON::XS is many times |
|
|
875 | faster for small messages and b) most importantly, after years of |
|
|
876 | experience we found that object serialisation is causing more problems |
|
|
877 | than it gains: Just like function calls, objects simply do not travel |
|
|
878 | easily over the network, mostly because they will always be a copy, so you |
|
|
879 | always have to re-think your design. |
|
|
880 | |
|
|
881 | Keeping your messages simple, concentrating on data structures rather than |
|
|
882 | objects, will keep your messages clean, tidy and efficient. |
|
|
883 | |
|
|
884 | =back |
|
|
885 | |
760 | =head1 SEE ALSO |
886 | =head1 SEE ALSO |
761 | |
887 | |
762 | L<AnyEvent>. |
888 | L<AnyEvent>. |
763 | |
889 | |
764 | =head1 AUTHOR |
890 | =head1 AUTHOR |