… | |
… | |
4 | |
4 | |
5 | =head1 SYNOPSIS |
5 | =head1 SYNOPSIS |
6 | |
6 | |
7 | use AnyEvent::MP; |
7 | use AnyEvent::MP; |
8 | |
8 | |
9 | NODE # returns this node identifier |
|
|
10 | $NODE # contains this node identifier |
9 | $NODE # contains this node's noderef |
|
|
10 | NODE # returns this node's noderef |
|
|
11 | NODE $port # returns the noderef of the port |
11 | |
12 | |
12 | snd $port, type => data...; |
13 | snd $port, type => data...; |
|
|
14 | |
|
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15 | $SELF # receiving/own port id in rcv callbacks |
13 | |
16 | |
14 | rcv $port, smartmatch => $cb->($port, @msg); |
17 | rcv $port, smartmatch => $cb->($port, @msg); |
15 | |
18 | |
16 | # examples: |
19 | # examples: |
17 | rcv $port2, ping => sub { snd $_[0], "pong"; 0 }; |
20 | rcv $port2, ping => sub { snd $_[0], "pong"; 0 }; |
… | |
… | |
27 | This module (-family) implements a simple message passing framework. |
30 | This module (-family) implements a simple message passing framework. |
28 | |
31 | |
29 | Despite its simplicity, you can securely message other processes running |
32 | Despite its simplicity, you can securely message other processes running |
30 | on the same or other hosts. |
33 | on the same or other hosts. |
31 | |
34 | |
|
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35 | For an introduction to this module family, see the L<AnyEvent::MP::Intro> |
|
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36 | manual page. |
|
|
37 | |
32 | At the moment, this module family is severly brokena nd underdocumented, |
38 | At the moment, this module family is severly broken and underdocumented, |
33 | so do not use. This was uploaded mainly to resreve the CPAN namespace - |
39 | so do not use. This was uploaded mainly to reserve the CPAN namespace - |
34 | stay tuned! |
40 | stay tuned! The basic API should be finished, however. |
35 | |
41 | |
36 | =head1 CONCEPTS |
42 | =head1 CONCEPTS |
37 | |
43 | |
38 | =over 4 |
44 | =over 4 |
39 | |
45 | |
40 | =item port |
46 | =item port |
41 | |
47 | |
42 | A port is something you can send messages to with the C<snd> function, and |
48 | A port is something you can send messages to (with the C<snd> function). |
43 | you can register C<rcv> handlers with. All C<rcv> handlers will receive |
49 | |
44 | messages they match, messages will not be queued. |
50 | Some ports allow you to register C<rcv> handlers that can match specific |
|
|
51 | messages. All C<rcv> handlers will receive messages they match, messages |
|
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52 | will not be queued. |
45 | |
53 | |
46 | =item port id - C<noderef#portname> |
54 | =item port id - C<noderef#portname> |
47 | |
55 | |
48 | A port id is always the noderef, a hash-mark (C<#>) as separator, followed |
56 | A port id is normaly the concatenation of a noderef, a hash-mark (C<#>) as |
49 | by a port name (a printable string of unspecified format). |
57 | separator, and a port name (a printable string of unspecified format). An |
|
|
58 | exception is the the node port, whose ID is identical to its node |
|
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59 | reference. |
50 | |
60 | |
51 | =item node |
61 | =item node |
52 | |
62 | |
53 | A node is a single process containing at least one port - the node |
63 | 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, |
64 | port. You can send messages to node ports to find existing ports or to |
55 | among other things. |
65 | create new ports, among other things. |
56 | |
66 | |
57 | Initially, nodes are either private (single-process only) or hidden |
67 | Nodes are either private (single-process only), slaves (connected to a |
58 | (connected to a master node only). Only when they epxlicitly "become |
68 | master node only) or public nodes (connectable from unrelated nodes). |
59 | public" can you send them messages from unrelated other nodes. |
|
|
60 | |
69 | |
61 | =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> |
62 | |
71 | |
63 | A noderef is a string that either uniquely identifies a given node (for |
72 | A node reference is a string that either simply identifies the node (for |
64 | private and hidden nodes), or contains a recipe on how to reach a given |
73 | private and slave nodes), or contains a recipe on how to reach a given |
65 | node (for public nodes). |
74 | node (for public nodes). |
66 | |
75 | |
|
|
76 | This recipe is simply a comma-separated list of C<address:port> pairs (for |
|
|
77 | TCP/IP, other protocols might look different). |
|
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78 | |
|
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79 | Node references come in two flavours: resolved (containing only numerical |
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80 | addresses) or unresolved (where hostnames are used instead of addresses). |
|
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81 | |
|
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82 | Before using an unresolved node reference in a message you first have to |
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83 | resolve it. |
|
|
84 | |
67 | =back |
85 | =back |
68 | |
86 | |
69 | =head1 VARIABLES/FUNCTIONS |
87 | =head1 VARIABLES/FUNCTIONS |
70 | |
88 | |
71 | =over 4 |
89 | =over 4 |
… | |
… | |
82 | |
100 | |
83 | use AE (); |
101 | use AE (); |
84 | |
102 | |
85 | use base "Exporter"; |
103 | use base "Exporter"; |
86 | |
104 | |
87 | our $VERSION = '0.02'; |
105 | our $VERSION = '0.1'; |
88 | our @EXPORT = qw( |
106 | our @EXPORT = qw( |
89 | NODE $NODE $PORT snd rcv _any_ |
107 | NODE $NODE *SELF node_of _any_ |
90 | create_port create_port_on |
108 | resolve_node initialise_node |
91 | become_slave become_public |
109 | snd rcv mon kil reg psub |
|
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110 | port |
92 | ); |
111 | ); |
93 | |
112 | |
|
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113 | our $SELF; |
|
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114 | |
|
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115 | sub _self_die() { |
|
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116 | my $msg = $@; |
|
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117 | $msg =~ s/\n+$// unless ref $msg; |
|
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118 | kil $SELF, die => $msg; |
|
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119 | } |
|
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120 | |
94 | =item NODE / $NODE |
121 | =item $thisnode = NODE / $NODE |
95 | |
122 | |
96 | The C<NODE ()> function and the C<$NODE> variable contain the noderef of |
123 | The C<NODE> function returns, and the C<$NODE> variable contains |
97 | the local node. The value is initialised by a call to C<become_public> or |
124 | the noderef of the local node. The value is initialised by a call |
98 | C<become_slave>, after which all local port identifiers become invalid. |
125 | to C<become_public> or C<become_slave>, after which all local port |
|
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126 | identifiers become invalid. |
|
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127 | |
|
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128 | =item $noderef = node_of $portid |
|
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129 | |
|
|
130 | Extracts and returns the noderef from a portid or a noderef. |
|
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131 | |
|
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132 | =item $cv = resolve_node $noderef |
|
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133 | |
|
|
134 | Takes an unresolved node reference that may contain hostnames and |
|
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135 | abbreviated IDs, resolves all of them and returns a resolved node |
|
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136 | reference. |
|
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137 | |
|
|
138 | In addition to C<address:port> pairs allowed in resolved noderefs, the |
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139 | following forms are supported: |
|
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140 | |
|
|
141 | =over 4 |
|
|
142 | |
|
|
143 | =item the empty string |
|
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144 | |
|
|
145 | An empty-string component gets resolved as if the default port (4040) was |
|
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146 | specified. |
|
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147 | |
|
|
148 | =item naked port numbers (e.g. C<1234>) |
|
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149 | |
|
|
150 | These are resolved by prepending the local nodename and a colon, to be |
|
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151 | further resolved. |
|
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152 | |
|
|
153 | =item hostnames (e.g. C<localhost:1234>, C<localhost>) |
|
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154 | |
|
|
155 | These are resolved by using AnyEvent::DNS to resolve them, optionally |
|
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156 | looking up SRV records for the C<aemp=4040> port, if no port was |
|
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157 | specified. |
|
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158 | |
|
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159 | =back |
|
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160 | |
|
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161 | =item $SELF |
|
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162 | |
|
|
163 | Contains the current port id while executing C<rcv> callbacks or C<psub> |
|
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164 | blocks. |
|
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165 | |
|
|
166 | =item SELF, %SELF, @SELF... |
|
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167 | |
|
|
168 | Due to some quirks in how perl exports variables, it is impossible to |
|
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169 | just export C<$SELF>, all the symbols called C<SELF> are exported by this |
|
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170 | module, but only C<$SELF> is currently used. |
99 | |
171 | |
100 | =item snd $portid, type => @data |
172 | =item snd $portid, type => @data |
101 | |
173 | |
102 | =item snd $portid, @msg |
174 | =item snd $portid, @msg |
103 | |
175 | |
… | |
… | |
117 | JSON is used, then only strings, numbers and arrays and hashes consisting |
189 | JSON is used, then only strings, numbers and arrays and hashes consisting |
118 | of those are allowed (no objects). When Storable is used, then anything |
190 | of those are allowed (no objects). When Storable is used, then anything |
119 | that Storable can serialise and deserialise is allowed, and for the local |
191 | that Storable can serialise and deserialise is allowed, and for the local |
120 | node, anything can be passed. |
192 | node, anything can be passed. |
121 | |
193 | |
122 | =item $local_port = create_port |
194 | =item $local_port = port |
123 | |
195 | |
124 | Create a new local port object. See the next section for allowed methods. |
196 | Create a new local port object that can be used either as a pattern |
|
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197 | matching port ("full port") or a single-callback port ("miniport"), |
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198 | depending on how C<rcv> callbacks are bound to the object. |
125 | |
199 | |
126 | =cut |
200 | =item $portid = port { my @msg = @_; $finished } |
127 | |
201 | |
128 | sub create_port { |
202 | Creates a "mini port", that is, a very lightweight port without any |
129 | my $id = "$AnyEvent::MP::Base::UNIQ." . ++$AnyEvent::MP::Base::ID; |
203 | pattern matching behind it, and returns its ID. |
130 | |
204 | |
131 | my $self = bless { |
205 | The block will be called for every message received on the port. When the |
132 | id => "$NODE#$id", |
206 | callback returns a true value its job is considered "done" and the port |
133 | names => [$id], |
207 | will be destroyed. Otherwise it will stay alive. |
134 | }, "AnyEvent::MP::Port"; |
|
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135 | |
208 | |
136 | $AnyEvent::MP::Base::PORT{$id} = sub { |
209 | The message will be passed as-is, no extra argument (i.e. no port id) will |
137 | unshift @_, $self; |
210 | be passed to the callback. |
138 | |
211 | |
139 | for (@{ $self->{rc0}{$_[1]} }) { |
212 | If you need the local port id in the callback, this works nicely: |
140 | $_ && &{$_->[0]} |
|
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141 | && undef $_; |
|
|
142 | } |
|
|
143 | |
213 | |
144 | for (@{ $self->{rcv}{$_[1]} }) { |
214 | my $port; $port = port { |
145 | $_ && [@_[1 .. @{$_->[1]}]] ~~ $_->[1] |
215 | snd $otherport, reply => $port; |
146 | && &{$_->[0]} |
|
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147 | && undef $_; |
|
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148 | } |
|
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149 | |
|
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150 | for (@{ $self->{any} }) { |
|
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151 | $_ && [@_[0 .. $#{$_->[1]}]] ~~ $_->[1] |
|
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152 | && &{$_->[0]} |
|
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153 | && undef $_; |
|
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154 | } |
|
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155 | }; |
216 | }; |
156 | |
217 | |
157 | $self |
218 | =cut |
|
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219 | |
|
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220 | sub port(;&) { |
|
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221 | my $id = "$UNIQ." . $ID++; |
|
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222 | my $port = "$NODE#$id"; |
|
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223 | |
|
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224 | if (@_) { |
|
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225 | my $cb = shift; |
|
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226 | $PORT{$id} = sub { |
|
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227 | local $SELF = $port; |
|
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228 | eval { |
|
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229 | &$cb |
|
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230 | and kil $id; |
|
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231 | }; |
|
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232 | _self_die if $@; |
|
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233 | }; |
|
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234 | } else { |
|
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235 | my $self = bless { |
|
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236 | id => "$NODE#$id", |
|
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237 | }, "AnyEvent::MP::Port"; |
|
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238 | |
|
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239 | $PORT_DATA{$id} = $self; |
|
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240 | $PORT{$id} = sub { |
|
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241 | local $SELF = $port; |
|
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242 | |
|
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243 | eval { |
|
|
244 | for (@{ $self->{rc0}{$_[0]} }) { |
|
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245 | $_ && &{$_->[0]} |
|
|
246 | && undef $_; |
|
|
247 | } |
|
|
248 | |
|
|
249 | for (@{ $self->{rcv}{$_[0]} }) { |
|
|
250 | $_ && [@_[1 .. @{$_->[1]}]] ~~ $_->[1] |
|
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251 | && &{$_->[0]} |
|
|
252 | && undef $_; |
|
|
253 | } |
|
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254 | |
|
|
255 | for (@{ $self->{any} }) { |
|
|
256 | $_ && [@_[0 .. $#{$_->[1]}]] ~~ $_->[1] |
|
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257 | && &{$_->[0]} |
|
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258 | && undef $_; |
|
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259 | } |
|
|
260 | }; |
|
|
261 | _self_die if $@; |
|
|
262 | }; |
|
|
263 | } |
|
|
264 | |
|
|
265 | $port |
158 | } |
266 | } |
159 | |
267 | |
160 | =item $portid = create_miniport { } |
268 | =item reg $portid, $name |
161 | |
269 | |
162 | Creates a "mini port", that is, a port without much #TODO |
270 | Registers the given port under the name C<$name>. If the name already |
|
|
271 | exists it is replaced. |
163 | |
272 | |
164 | =cut |
273 | A port can only be registered under one well known name. |
165 | |
274 | |
166 | sub create_miniport(&) { |
275 | A port automatically becomes unregistered when it is killed. |
167 | my $cb = shift; |
|
|
168 | my $id = "$AnyEvent::MP::Base::UNIQ." . ++$AnyEvent::MP::Base::ID; |
|
|
169 | |
276 | |
170 | $AnyEvent::MP::Base::PORT{$id} = sub { |
277 | =cut |
171 | &$cb |
|
|
172 | and delete $AnyEvent::MP::Base::PORT{$id}; |
|
|
173 | }; |
|
|
174 | |
278 | |
175 | "$NODE#$id" |
279 | sub reg(@) { |
|
|
280 | my ($portid, $name) = @_; |
|
|
281 | |
|
|
282 | $REG{$name} = $portid; |
176 | } |
283 | } |
177 | |
284 | |
178 | package AnyEvent::MP::Port; |
285 | =item rcv $portid, $callback->(@msg) |
179 | |
286 | |
180 | =back |
287 | Replaces the callback on the specified miniport (or newly created port |
|
|
288 | object, see C<port>). Full ports are configured with the following calls: |
181 | |
289 | |
182 | =head1 METHODS FOR PORT OBJECTS |
290 | =item rcv $portid, tagstring => $callback->(@msg), ... |
183 | |
291 | |
184 | =over 4 |
292 | =item rcv $portid, $smartmatch => $callback->(@msg), ... |
185 | |
293 | |
186 | =item "$port" |
|
|
187 | |
|
|
188 | A port object stringifies to its port ID, so can be used directly for |
|
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189 | C<snd> operations. |
|
|
190 | |
|
|
191 | =cut |
|
|
192 | |
|
|
193 | use overload |
|
|
194 | '""' => sub { $_[0]{id} }, |
|
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195 | fallback => 1; |
|
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196 | |
|
|
197 | =item $port->rcv (type => $callback->($port, @msg)) |
|
|
198 | |
|
|
199 | =item $port->rcv ($smartmatch => $callback->($port, @msg)) |
|
|
200 | |
|
|
201 | =item $port->rcv ([$smartmatch...] => $callback->($port, @msg)) |
294 | =item rcv $portid, [$smartmatch...] => $callback->(@msg), ... |
202 | |
295 | |
203 | Register a callback on the given port. |
296 | Register callbacks to be called on matching messages on the given full |
|
|
297 | port (or newly created port). |
204 | |
298 | |
205 | The callback has to return a true value when its work is done, after |
299 | The callback has to return a true value when its work is done, after |
206 | which is will be removed, or a false value in which case it will stay |
300 | which is will be removed, or a false value in which case it will stay |
207 | registered. |
301 | registered. |
208 | |
302 | |
|
|
303 | The global C<$SELF> (exported by this module) contains C<$portid> while |
|
|
304 | executing the callback. |
|
|
305 | |
|
|
306 | Runtime errors wdurign callback execution will result in the port being |
|
|
307 | C<kil>ed. |
|
|
308 | |
209 | If the match is an array reference, then it will be matched against the |
309 | If the match is an array reference, then it will be matched against the |
210 | first elements of the message, otherwise only the first element is being |
310 | first elements of the message, otherwise only the first element is being |
211 | matched. |
311 | matched. |
212 | |
312 | |
213 | Any element in the match that is specified as C<_any_> (a function |
313 | Any element in the match that is specified as C<_any_> (a function |
… | |
… | |
218 | also the most efficient match (by far). |
318 | also the most efficient match (by far). |
219 | |
319 | |
220 | =cut |
320 | =cut |
221 | |
321 | |
222 | sub rcv($@) { |
322 | sub rcv($@) { |
223 | my ($self, $match, $cb) = @_; |
323 | my $portid = shift; |
|
|
324 | my ($noderef, $port) = split /#/, $port, 2; |
224 | |
325 | |
|
|
326 | ($NODE{$noderef} || add_node $noderef) == $NODE{""} |
|
|
327 | or Carp::croak "$noderef#$port: rcv can only be called on local ports, caught"; |
|
|
328 | |
|
|
329 | my $self = $PORT_DATA{$port} |
|
|
330 | or Carp::croak "$noderef#$port: rcv can only be called on message matching ports, caught"; |
|
|
331 | |
|
|
332 | "AnyEvent::MP::Port" eq ref $self |
|
|
333 | or Carp::croak "$noderef#$port: rcv can only be called on message matching ports, caught"; |
|
|
334 | |
|
|
335 | while (@_) { |
|
|
336 | my ($match, $cb) = splice @_, 0, 2; |
|
|
337 | |
225 | if (!ref $match) { |
338 | if (!ref $match) { |
226 | push @{ $self->{rc0}{$match} }, [$cb]; |
339 | push @{ $self->{rc0}{$match} }, [$cb]; |
227 | } elsif (("ARRAY" eq ref $match && !ref $match->[0])) { |
340 | } elsif (("ARRAY" eq ref $match && !ref $match->[0])) { |
228 | my ($type, @match) = @$match; |
341 | my ($type, @match) = @$match; |
229 | @match |
342 | @match |
230 | ? push @{ $self->{rcv}{$match->[0]} }, [$cb, \@match] |
343 | ? push @{ $self->{rcv}{$match->[0]} }, [$cb, \@match] |
231 | : push @{ $self->{rc0}{$match->[0]} }, [$cb]; |
344 | : push @{ $self->{rc0}{$match->[0]} }, [$cb]; |
232 | } else { |
345 | } else { |
233 | push @{ $self->{any} }, [$cb, $match]; |
346 | push @{ $self->{any} }, [$cb, $match]; |
|
|
347 | } |
|
|
348 | } |
|
|
349 | |
|
|
350 | $portid |
|
|
351 | } |
|
|
352 | |
|
|
353 | =item $closure = psub { BLOCK } |
|
|
354 | |
|
|
355 | Remembers C<$SELF> and creates a closure out of the BLOCK. When the |
|
|
356 | closure is executed, sets up the environment in the same way as in C<rcv> |
|
|
357 | callbacks, i.e. runtime errors will cause the port to get C<kil>ed. |
|
|
358 | |
|
|
359 | This is useful when you register callbacks from C<rcv> callbacks: |
|
|
360 | |
|
|
361 | rcv delayed_reply => sub { |
|
|
362 | my ($delay, @reply) = @_; |
|
|
363 | my $timer = AE::timer $delay, 0, psub { |
|
|
364 | snd @reply, $SELF; |
|
|
365 | }; |
|
|
366 | }; |
|
|
367 | |
|
|
368 | =cut |
|
|
369 | |
|
|
370 | sub psub(&) { |
|
|
371 | my $cb = shift; |
|
|
372 | |
|
|
373 | my $port = $SELF |
|
|
374 | or Carp::croak "psub can only be called from within rcv or psub callbacks, not"; |
|
|
375 | |
|
|
376 | sub { |
|
|
377 | local $SELF = $port; |
|
|
378 | |
|
|
379 | if (wantarray) { |
|
|
380 | my @res = eval { &$cb }; |
|
|
381 | _self_die if $@; |
|
|
382 | @res |
|
|
383 | } else { |
|
|
384 | my $res = eval { &$cb }; |
|
|
385 | _self_die if $@; |
|
|
386 | $res |
|
|
387 | } |
234 | } |
388 | } |
235 | } |
389 | } |
236 | |
390 | |
237 | =item $port->register ($name) |
391 | =item $guard = mon $portid, $cb->(@reason) |
238 | |
392 | |
239 | Registers the given port under the well known name C<$name>. If the name |
393 | =item $guard = mon $portid, $otherport |
240 | already exists it is replaced. |
|
|
241 | |
394 | |
242 | A port can only be registered under one well known name. |
395 | =item $guard = mon $portid, $otherport, @msg |
243 | |
396 | |
244 | =cut |
397 | Monitor the given port and do something when the port is killed. |
245 | |
398 | |
246 | sub register { |
399 | In the first form, the callback is simply called with any number |
247 | my ($self, $name) = @_; |
400 | of C<@reason> elements (no @reason means that the port was deleted |
|
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401 | "normally"). Note also that I<< the callback B<must> never die >>, so use |
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402 | C<eval> if unsure. |
248 | |
403 | |
249 | $self->{wkname} = $name; |
404 | In the second form, the other port will be C<kil>'ed with C<@reason>, iff |
250 | $AnyEvent::MP::Base::WKP{$name} = "$self"; |
405 | a @reason was specified, i.e. on "normal" kils nothing happens, while |
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406 | under all other conditions, the other port is killed with the same reason. |
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407 | |
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408 | In the last form, a message of the form C<@msg, @reason> will be C<snd>. |
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409 | |
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410 | Example: call a given callback when C<$port> is killed. |
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411 | |
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412 | mon $port, sub { warn "port died because of <@_>\n" }; |
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413 | |
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414 | Example: kill ourselves when C<$port> is killed abnormally. |
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415 | |
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416 | mon $port, $self; |
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417 | |
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418 | Example: send us a restart message another C<$port> is killed. |
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419 | |
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420 | mon $port, $self => "restart"; |
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421 | |
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422 | =cut |
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423 | |
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424 | sub mon { |
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425 | my ($noderef, $port) = split /#/, shift, 2; |
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426 | |
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427 | my $node = $NODE{$noderef} || add_node $noderef; |
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428 | |
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429 | my $cb = shift; |
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430 | |
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431 | unless (ref $cb) { |
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432 | if (@_) { |
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433 | # send a kill info message |
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434 | my (@msg) = ($cb, @_); |
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435 | $cb = sub { snd @msg, @_ }; |
|
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436 | } else { |
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437 | # simply kill other port |
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438 | my $port = $cb; |
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439 | $cb = sub { kil $port, @_ if @_ }; |
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440 | } |
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441 | } |
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442 | |
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443 | $node->monitor ($port, $cb); |
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444 | |
|
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445 | defined wantarray |
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446 | and AnyEvent::Util::guard { $node->unmonitor ($port, $cb) } |
251 | } |
447 | } |
252 | |
448 | |
253 | =item $port->destroy |
449 | =item $guard = mon_guard $port, $ref, $ref... |
254 | |
450 | |
255 | Explicitly destroy/remove/nuke/vaporise the port. |
451 | Monitors the given C<$port> and keeps the passed references. When the port |
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452 | is killed, the references will be freed. |
256 | |
453 | |
257 | Ports are normally kept alive by there mere existance alone, and need to |
454 | Optionally returns a guard that will stop the monitoring. |
258 | be destroyed explicitly. |
|
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259 | |
455 | |
260 | =cut |
456 | This function is useful when you create e.g. timers or other watchers and |
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457 | want to free them when the port gets killed: |
261 | |
458 | |
262 | sub destroy { |
459 | $port->rcv (start => sub { |
263 | my ($self) = @_; |
460 | my $timer; $timer = mon_guard $port, AE::timer 1, 1, sub { |
|
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461 | undef $timer if 0.9 < rand; |
|
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462 | }); |
|
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463 | }); |
264 | |
464 | |
265 | delete $AnyEvent::MP::Base::WKP{ $self->{wkname} }; |
465 | =cut |
266 | |
466 | |
267 | delete $AnyEvent::MP::Base::PORT{$_} |
467 | sub mon_guard { |
268 | for @{ $self->{names} }; |
468 | my ($port, @refs) = @_; |
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|
469 | |
|
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470 | mon $port, sub { 0 && @refs } |
269 | } |
471 | } |
270 | |
472 | |
|
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473 | =item lnk $port1, $port2 |
|
|
474 | |
|
|
475 | Link two ports. This is simply a shorthand for: |
|
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476 | |
|
|
477 | mon $port1, $port2; |
|
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478 | mon $port2, $port1; |
|
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479 | |
|
|
480 | It means that if either one is killed abnormally, the other one gets |
|
|
481 | killed as well. |
|
|
482 | |
|
|
483 | =item kil $portid[, @reason] |
|
|
484 | |
|
|
485 | Kill the specified port with the given C<@reason>. |
|
|
486 | |
|
|
487 | If no C<@reason> is specified, then the port is killed "normally" (linked |
|
|
488 | ports will not be kileld, or even notified). |
|
|
489 | |
|
|
490 | Otherwise, linked ports get killed with the same reason (second form of |
|
|
491 | C<mon>, see below). |
|
|
492 | |
|
|
493 | Runtime errors while evaluating C<rcv> callbacks or inside C<psub> blocks |
|
|
494 | will be reported as reason C<< die => $@ >>. |
|
|
495 | |
|
|
496 | Transport/communication errors are reported as C<< transport_error => |
|
|
497 | $message >>. |
|
|
498 | |
271 | =back |
499 | =back |
272 | |
500 | |
273 | =head1 FUNCTIONS FOR NODES |
501 | =head1 FUNCTIONS FOR NODES |
274 | |
502 | |
275 | =over 4 |
503 | =over 4 |
276 | |
504 | |
277 | =item mon $noderef, $callback->($noderef, $status, $) |
505 | =item become_public $noderef |
278 | |
|
|
279 | Monitors the given noderef. |
|
|
280 | |
|
|
281 | =item become_public endpoint... |
|
|
282 | |
506 | |
283 | Tells the node to become a public node, i.e. reachable from other nodes. |
507 | Tells the node to become a public node, i.e. reachable from other nodes. |
284 | |
508 | |
285 | If no arguments are given, or the first argument is C<undef>, then |
509 | The first argument is the (unresolved) node reference of the local node |
286 | AnyEvent::MP tries to bind on port C<4040> on all IP addresses that the |
510 | (if missing then the empty string is used). |
287 | local nodename resolves to. |
|
|
288 | |
511 | |
289 | Otherwise the first argument must be an array-reference with transport |
512 | It is quite common to not specify anything, in which case the local node |
290 | endpoints ("ip:port", "hostname:port") or port numbers (in which case the |
513 | tries to listen on the default port, or to only specify a port number, in |
291 | local nodename is used as hostname). The endpoints are all resolved and |
514 | which case AnyEvent::MP tries to guess the local addresses. |
292 | will become the node reference. |
|
|
293 | |
515 | |
294 | =cut |
516 | =cut |
295 | |
517 | |
296 | =back |
518 | =back |
297 | |
519 | |
… | |
… | |
300 | Nodes understand the following messages sent to them. Many of them take |
522 | Nodes understand the following messages sent to them. Many of them take |
301 | arguments called C<@reply>, which will simply be used to compose a reply |
523 | arguments called C<@reply>, which will simply be used to compose a reply |
302 | message - C<$reply[0]> is the port to reply to, C<$reply[1]> the type and |
524 | message - C<$reply[0]> is the port to reply to, C<$reply[1]> the type and |
303 | the remaining arguments are simply the message data. |
525 | the remaining arguments are simply the message data. |
304 | |
526 | |
|
|
527 | While other messages exist, they are not public and subject to change. |
|
|
528 | |
305 | =over 4 |
529 | =over 4 |
306 | |
530 | |
307 | =cut |
531 | =cut |
308 | |
532 | |
309 | =item wkp => $name, @reply |
533 | =item lookup => $name, @reply |
310 | |
534 | |
311 | Replies with the port ID of the specified well-known port, or C<undef>. |
535 | Replies with the port ID of the specified well-known port, or C<undef>. |
312 | |
536 | |
313 | =item devnull => ... |
537 | =item devnull => ... |
314 | |
538 | |
… | |
… | |
337 | snd $NODE, time => $myport, timereply => 1, 2; |
561 | snd $NODE, time => $myport, timereply => 1, 2; |
338 | # => snd $myport, timereply => 1, 2, <time> |
562 | # => snd $myport, timereply => 1, 2, <time> |
339 | |
563 | |
340 | =back |
564 | =back |
341 | |
565 | |
|
|
566 | =head1 AnyEvent::MP vs. Distributed Erlang |
|
|
567 | |
|
|
568 | AnyEvent::MP got lots of its ideas from distributed erlang (erlang node |
|
|
569 | == aemp node, erlang process == aemp port), so many of the documents and |
|
|
570 | programming techniques employed by erlang apply to AnyEvent::MP. Here is a |
|
|
571 | sample: |
|
|
572 | |
|
|
573 | http://www.erlang.se/doc/programming_rules.shtml |
|
|
574 | http://erlang.org/doc/getting_started/part_frame.html # chapters 3 and 4 |
|
|
575 | http://erlang.org/download/erlang-book-part1.pdf # chapters 5 and 6 |
|
|
576 | http://erlang.org/download/armstrong_thesis_2003.pdf # chapters 4 and 5 |
|
|
577 | |
|
|
578 | Despite the similarities, there are also some important differences: |
|
|
579 | |
|
|
580 | =over 4 |
|
|
581 | |
|
|
582 | =item * Node references contain the recipe on how to contact them. |
|
|
583 | |
|
|
584 | Erlang relies on special naming and DNS to work everywhere in the |
|
|
585 | same way. AEMP relies on each node knowing it's own address(es), with |
|
|
586 | convenience functionality. |
|
|
587 | |
|
|
588 | This means that AEMP requires a less tightly controlled environment at the |
|
|
589 | cost of longer node references and a slightly higher management overhead. |
|
|
590 | |
|
|
591 | =item * Erlang uses processes and a mailbox, AEMP does not queue. |
|
|
592 | |
|
|
593 | Erlang uses processes that selctively receive messages, and therefore |
|
|
594 | needs a queue. AEMP is event based, queuing messages would serve no useful |
|
|
595 | purpose. |
|
|
596 | |
|
|
597 | (But see L<Coro::MP> for a more erlang-like process model on top of AEMP). |
|
|
598 | |
|
|
599 | =item * Erlang sends are synchronous, AEMP sends are asynchronous. |
|
|
600 | |
|
|
601 | Sending messages in erlang is synchronous and blocks the process. AEMP |
|
|
602 | sends are immediate, connection establishment is handled in the |
|
|
603 | background. |
|
|
604 | |
|
|
605 | =item * Erlang can silently lose messages, AEMP cannot. |
|
|
606 | |
|
|
607 | Erlang makes few guarantees on messages delivery - messages can get lost |
|
|
608 | without any of the processes realising it (i.e. you send messages a, b, |
|
|
609 | and c, and the other side only receives messages a and c). |
|
|
610 | |
|
|
611 | AEMP guarantees correct ordering, and the guarantee that there are no |
|
|
612 | holes in the message sequence. |
|
|
613 | |
|
|
614 | =item * In erlang, processes can be declared dead and later be found to be |
|
|
615 | alive. |
|
|
616 | |
|
|
617 | In erlang it can happen that a monitored process is declared dead and |
|
|
618 | linked processes get killed, but later it turns out that the process is |
|
|
619 | still alive - and can receive messages. |
|
|
620 | |
|
|
621 | In AEMP, when port monitoring detects a port as dead, then that port will |
|
|
622 | eventually be killed - it cannot happen that a node detects a port as dead |
|
|
623 | and then later sends messages to it, finding it is still alive. |
|
|
624 | |
|
|
625 | =item * Erlang can send messages to the wrong port, AEMP does not. |
|
|
626 | |
|
|
627 | In erlang it is quite possible that a node that restarts reuses a process |
|
|
628 | ID known to other nodes for a completely different process, causing |
|
|
629 | messages destined for that process to end up in an unrelated process. |
|
|
630 | |
|
|
631 | AEMP never reuses port IDs, so old messages or old port IDs floating |
|
|
632 | around in the network will not be sent to an unrelated port. |
|
|
633 | |
|
|
634 | =item * Erlang uses unprotected connections, AEMP uses secure |
|
|
635 | authentication and can use TLS. |
|
|
636 | |
|
|
637 | AEMP can use a proven protocol - SSL/TLS - to protect connections and |
|
|
638 | securely authenticate nodes. |
|
|
639 | |
|
|
640 | =item * The AEMP protocol is optimised for both text-based and binary |
|
|
641 | communications. |
|
|
642 | |
|
|
643 | The AEMP protocol, unlike the erlang protocol, supports both |
|
|
644 | language-independent text-only protocols (good for debugging) and binary, |
|
|
645 | language-specific serialisers (e.g. Storable). |
|
|
646 | |
|
|
647 | It has also been carefully designed to be implementable in other languages |
|
|
648 | with a minimum of work while gracefully degrading fucntionality to make the |
|
|
649 | protocol simple. |
|
|
650 | |
|
|
651 | =back |
|
|
652 | |
342 | =head1 SEE ALSO |
653 | =head1 SEE ALSO |
343 | |
654 | |
344 | L<AnyEvent>. |
655 | L<AnyEvent>. |
345 | |
656 | |
346 | =head1 AUTHOR |
657 | =head1 AUTHOR |