… | |
… | |
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 | |
|
|
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 }; |
… | |
… | |
20 | |
23 | |
21 | # more, smarter, matches (_any_ is exported by this module) |
24 | # more, smarter, matches (_any_ is exported by this module) |
22 | rcv $port, [child_died => $pid] => sub { ... |
25 | rcv $port, [child_died => $pid] => sub { ... |
23 | rcv $port, [_any_, _any_, 3] => sub { .. $_[2] is 3 |
26 | rcv $port, [_any_, _any_, 3] => sub { .. $_[2] is 3 |
24 | |
27 | |
|
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28 | # monitoring |
|
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29 | mon $port, $cb->(@msg) # callback is invoked on death |
|
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30 | mon $port, $otherport # kill otherport on abnormal death |
|
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31 | mon $port, $otherport, @msg # send message on death |
|
|
32 | |
25 | =head1 DESCRIPTION |
33 | =head1 DESCRIPTION |
26 | |
34 | |
27 | This module (-family) implements a simple message passing framework. |
35 | This module (-family) implements a simple message passing framework. |
28 | |
36 | |
29 | Despite its simplicity, you can securely message other processes running |
37 | Despite its simplicity, you can securely message other processes running |
30 | on the same or other hosts. |
38 | on the same or other hosts. |
31 | |
39 | |
|
|
40 | For an introduction to this module family, see the L<AnyEvent::MP::Intro> |
|
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41 | manual page. |
|
|
42 | |
32 | At the moment, this module family is severly brokena nd underdocumented, |
43 | At the moment, this module family is severly broken and underdocumented, |
33 | so do not use. This was uploaded mainly to reserve the CPAN namespace - |
44 | so do not use. This was uploaded mainly to reserve the CPAN namespace - |
34 | stay tuned! |
45 | stay tuned! The basic API should be finished, however. |
35 | |
46 | |
36 | =head1 CONCEPTS |
47 | =head1 CONCEPTS |
37 | |
48 | |
38 | =over 4 |
49 | =over 4 |
39 | |
50 | |
40 | =item port |
51 | =item port |
41 | |
52 | |
42 | A port is something you can send messages to with the C<snd> function, and |
53 | 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 |
54 | |
44 | messages they match, messages will not be queued. |
55 | Some ports allow you to register C<rcv> handlers that can match specific |
|
|
56 | messages. All C<rcv> handlers will receive messages they match, messages |
|
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57 | will not be queued. |
45 | |
58 | |
46 | =item port id - C<noderef#portname> |
59 | =item port id - C<noderef#portname> |
47 | |
60 | |
48 | A port id is always the noderef, a hash-mark (C<#>) as separator, followed |
61 | 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). |
62 | separator, and a port name (a printable string of unspecified format). An |
|
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63 | exception is the the node port, whose ID is identical to its node |
|
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64 | reference. |
50 | |
65 | |
51 | =item node |
66 | =item node |
52 | |
67 | |
53 | A node is a single process containing at least one port - the node |
68 | 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, |
69 | port. You can send messages to node ports to find existing ports or to |
55 | among other things. |
70 | create new ports, among other things. |
56 | |
71 | |
57 | Initially, nodes are either private (single-process only) or hidden |
72 | Nodes are either private (single-process only), slaves (connected to a |
58 | (connected to a master node only). Only when they epxlicitly "become |
73 | master node only) or public nodes (connectable from unrelated nodes). |
59 | public" can you send them messages from unrelated other nodes. |
|
|
60 | |
74 | |
61 | =item noderef - C<host:port,host:port...>, C<id@noderef>, C<id> |
75 | =item noderef - C<host:port,host:port...>, C<id@noderef>, C<id> |
62 | |
76 | |
63 | A noderef is a string that either uniquely identifies a given node (for |
77 | 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 |
78 | private and slave nodes), or contains a recipe on how to reach a given |
65 | node (for public nodes). |
79 | node (for public nodes). |
66 | |
80 | |
|
|
81 | This recipe is simply a comma-separated list of C<address:port> pairs (for |
|
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82 | TCP/IP, other protocols might look different). |
|
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83 | |
|
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84 | Node references come in two flavours: resolved (containing only numerical |
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85 | addresses) or unresolved (where hostnames are used instead of addresses). |
|
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86 | |
|
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87 | Before using an unresolved node reference in a message you first have to |
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88 | resolve it. |
|
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89 | |
67 | =back |
90 | =back |
68 | |
91 | |
69 | =head1 VARIABLES/FUNCTIONS |
92 | =head1 VARIABLES/FUNCTIONS |
70 | |
93 | |
71 | =over 4 |
94 | =over 4 |
… | |
… | |
82 | |
105 | |
83 | use AE (); |
106 | use AE (); |
84 | |
107 | |
85 | use base "Exporter"; |
108 | use base "Exporter"; |
86 | |
109 | |
87 | our $VERSION = '0.02'; |
110 | our $VERSION = '0.1'; |
88 | our @EXPORT = qw( |
111 | our @EXPORT = qw( |
89 | NODE $NODE $PORT snd rcv mon kil _any_ |
112 | NODE $NODE *SELF node_of _any_ |
90 | create_port create_port_on |
113 | resolve_node initialise_node |
|
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114 | snd rcv mon kil reg psub |
91 | miniport |
115 | port |
92 | become_slave become_public |
|
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93 | ); |
116 | ); |
94 | |
117 | |
|
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118 | our $SELF; |
|
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119 | |
|
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120 | sub _self_die() { |
|
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121 | my $msg = $@; |
|
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122 | $msg =~ s/\n+$// unless ref $msg; |
|
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123 | kil $SELF, die => $msg; |
|
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124 | } |
|
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125 | |
95 | =item NODE / $NODE |
126 | =item $thisnode = NODE / $NODE |
96 | |
127 | |
97 | The C<NODE ()> function and the C<$NODE> variable contain the noderef of |
128 | The C<NODE> function returns, and the C<$NODE> variable contains |
98 | the local node. The value is initialised by a call to C<become_public> or |
129 | the noderef of the local node. The value is initialised by a call |
99 | C<become_slave>, after which all local port identifiers become invalid. |
130 | to C<become_public> or C<become_slave>, after which all local port |
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131 | identifiers become invalid. |
100 | |
132 | |
|
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133 | =item $noderef = node_of $port |
|
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134 | |
|
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135 | Extracts and returns the noderef from a portid or a noderef. |
|
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136 | |
|
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137 | =item initialise_node $noderef, $seednode, $seednode... |
|
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138 | |
|
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139 | =item initialise_node "slave/", $master, $master... |
|
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140 | |
|
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141 | Before a node can talk to other nodes on the network it has to initialise |
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142 | itself - the minimum a node needs to know is it's own name, and optionally |
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143 | it should know the noderefs of some other nodes in the network. |
|
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144 | |
|
|
145 | This function initialises a node - it must be called exactly once (or |
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146 | never) before calling other AnyEvent::MP functions. |
|
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147 | |
|
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148 | All arguments are noderefs, which can be either resolved or unresolved. |
|
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149 | |
|
|
150 | There are two types of networked nodes, public nodes and slave nodes: |
|
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151 | |
|
|
152 | =over 4 |
|
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153 | |
|
|
154 | =item public nodes |
|
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155 | |
|
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156 | For public nodes, C<$noderef> must either be a (possibly unresolved) |
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157 | noderef, in which case it will be resolved, or C<undef> (or missing), in |
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158 | which case the noderef will be guessed. |
|
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159 | |
|
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160 | Afterwards, the node will bind itself on all endpoints and try to connect |
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161 | to all additional C<$seednodes> that are specified. Seednodes are optional |
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162 | and can be used to quickly bootstrap the node into an existing network. |
|
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163 | |
|
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164 | =item slave nodes |
|
|
165 | |
|
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166 | When the C<$noderef> is the special string C<slave/>, then the node will |
|
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167 | become a slave node. Slave nodes cannot be contacted from outside and will |
|
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168 | route most of their traffic to the master node that they attach to. |
|
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169 | |
|
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170 | At least one additional noderef is required: The node will try to connect |
|
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171 | to all of them and will become a slave attached to the first node it can |
|
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172 | successfully connect to. |
|
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173 | |
|
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174 | =back |
|
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175 | |
|
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176 | This function will block until all nodes have been resolved and, for slave |
|
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177 | nodes, until it has successfully established a connection to a master |
|
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178 | server. |
|
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179 | |
|
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180 | Example: become a public node listening on the default node. |
|
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181 | |
|
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182 | initialise_node; |
|
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183 | |
|
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184 | Example: become a public node, and try to contact some well-known master |
|
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185 | servers to become part of the network. |
|
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186 | |
|
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187 | initialise_node undef, "master1", "master2"; |
|
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188 | |
|
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189 | Example: become a public node listening on port C<4041>. |
|
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190 | |
|
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191 | initialise_node 4041; |
|
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192 | |
|
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193 | Example: become a public node, only visible on localhost port 4044. |
|
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194 | |
|
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195 | initialise_node "locahost:4044"; |
|
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196 | |
|
|
197 | Example: become a slave node to any of the specified master servers. |
|
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198 | |
|
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199 | initialise_node "slave/", "master1", "192.168.13.17", "mp.example.net"; |
|
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200 | |
|
|
201 | =item $cv = resolve_node $noderef |
|
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202 | |
|
|
203 | Takes an unresolved node reference that may contain hostnames and |
|
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204 | abbreviated IDs, resolves all of them and returns a resolved node |
|
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205 | reference. |
|
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206 | |
|
|
207 | In addition to C<address:port> pairs allowed in resolved noderefs, the |
|
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208 | following forms are supported: |
|
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209 | |
|
|
210 | =over 4 |
|
|
211 | |
|
|
212 | =item the empty string |
|
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213 | |
|
|
214 | An empty-string component gets resolved as if the default port (4040) was |
|
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215 | specified. |
|
|
216 | |
|
|
217 | =item naked port numbers (e.g. C<1234>) |
|
|
218 | |
|
|
219 | These are resolved by prepending the local nodename and a colon, to be |
|
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220 | further resolved. |
|
|
221 | |
|
|
222 | =item hostnames (e.g. C<localhost:1234>, C<localhost>) |
|
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223 | |
|
|
224 | These are resolved by using AnyEvent::DNS to resolve them, optionally |
|
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225 | looking up SRV records for the C<aemp=4040> port, if no port was |
|
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226 | specified. |
|
|
227 | |
|
|
228 | =back |
|
|
229 | |
|
|
230 | =item $SELF |
|
|
231 | |
|
|
232 | Contains the current port id while executing C<rcv> callbacks or C<psub> |
|
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233 | blocks. |
|
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234 | |
|
|
235 | =item SELF, %SELF, @SELF... |
|
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236 | |
|
|
237 | Due to some quirks in how perl exports variables, it is impossible to |
|
|
238 | just export C<$SELF>, all the symbols called C<SELF> are exported by this |
|
|
239 | module, but only C<$SELF> is currently used. |
|
|
240 | |
101 | =item snd $portid, type => @data |
241 | =item snd $port, type => @data |
102 | |
242 | |
103 | =item snd $portid, @msg |
243 | =item snd $port, @msg |
104 | |
244 | |
105 | Send the given message to the given port ID, which can identify either |
245 | Send the given message to the given port ID, which can identify either |
106 | a local or a remote port, and can be either a string or soemthignt hat |
246 | a local or a remote port, and can be either a string or soemthignt hat |
107 | stringifies a sa port ID (such as a port object :). |
247 | stringifies a sa port ID (such as a port object :). |
108 | |
248 | |
… | |
… | |
118 | JSON is used, then only strings, numbers and arrays and hashes consisting |
258 | JSON is used, then only strings, numbers and arrays and hashes consisting |
119 | of those are allowed (no objects). When Storable is used, then anything |
259 | of those are allowed (no objects). When Storable is used, then anything |
120 | that Storable can serialise and deserialise is allowed, and for the local |
260 | that Storable can serialise and deserialise is allowed, and for the local |
121 | node, anything can be passed. |
261 | node, anything can be passed. |
122 | |
262 | |
|
|
263 | =item $local_port = port |
|
|
264 | |
|
|
265 | Create a new local port object that can be used either as a pattern |
|
|
266 | matching port ("full port") or a single-callback port ("miniport"), |
|
|
267 | depending on how C<rcv> callbacks are bound to the object. |
|
|
268 | |
|
|
269 | =item $port = port { my @msg = @_; $finished } |
|
|
270 | |
|
|
271 | Creates a "miniport", that is, a very lightweight port without any pattern |
|
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272 | matching behind it, and returns its ID. Semantically the same as creating |
|
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273 | a port and calling C<rcv $port, $callback> on it. |
|
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274 | |
|
|
275 | The block will be called for every message received on the port. When the |
|
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276 | callback returns a true value its job is considered "done" and the port |
|
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277 | will be destroyed. Otherwise it will stay alive. |
|
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278 | |
|
|
279 | The message will be passed as-is, no extra argument (i.e. no port id) will |
|
|
280 | be passed to the callback. |
|
|
281 | |
|
|
282 | If you need the local port id in the callback, this works nicely: |
|
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283 | |
|
|
284 | my $port; $port = port { |
|
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285 | snd $otherport, reply => $port; |
|
|
286 | }; |
|
|
287 | |
|
|
288 | =cut |
|
|
289 | |
|
|
290 | sub rcv($@); |
|
|
291 | |
|
|
292 | sub port(;&) { |
|
|
293 | my $id = "$UNIQ." . $ID++; |
|
|
294 | my $port = "$NODE#$id"; |
|
|
295 | |
|
|
296 | if (@_) { |
|
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297 | rcv $port, shift; |
|
|
298 | } else { |
|
|
299 | $PORT{$id} = sub { }; # nop |
|
|
300 | } |
|
|
301 | |
|
|
302 | $port |
|
|
303 | } |
|
|
304 | |
|
|
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) |
|
|
325 | |
|
|
326 | Replaces the callback on the specified miniport (after converting it to |
|
|
327 | one if required). |
|
|
328 | |
|
|
329 | =item rcv $port, tagstring => $callback->(@msg), ... |
|
|
330 | |
|
|
331 | =item rcv $port, $smartmatch => $callback->(@msg), ... |
|
|
332 | |
|
|
333 | =item rcv $port, [$smartmatch...] => $callback->(@msg), ... |
|
|
334 | |
|
|
335 | Register callbacks to be called on matching messages on the given full |
|
|
336 | port (after converting it to one if required) and return the port. |
|
|
337 | |
|
|
338 | The callback has to return a true value when its work is done, after |
|
|
339 | which is will be removed, or a false value in which case it will stay |
|
|
340 | registered. |
|
|
341 | |
|
|
342 | The global C<$SELF> (exported by this module) contains C<$port> while |
|
|
343 | executing the callback. |
|
|
344 | |
|
|
345 | Runtime errors wdurign callback execution will result in the port being |
|
|
346 | C<kil>ed. |
|
|
347 | |
|
|
348 | If the match is an array reference, then it will be matched against the |
|
|
349 | first elements of the message, otherwise only the first element is being |
|
|
350 | matched. |
|
|
351 | |
|
|
352 | Any element in the match that is specified as C<_any_> (a function |
|
|
353 | exported by this module) matches any single element of the message. |
|
|
354 | |
|
|
355 | While not required, it is highly recommended that the first matching |
|
|
356 | element is a string identifying the message. The one-string-only match is |
|
|
357 | also the most efficient match (by far). |
|
|
358 | |
|
|
359 | Example: create a port and bind receivers on it in one go. |
|
|
360 | |
|
|
361 | my $port = rcv port, |
|
|
362 | msg1 => sub { ...; 0 }, |
|
|
363 | msg2 => sub { ...; 0 }, |
|
|
364 | ; |
|
|
365 | |
|
|
366 | Example: create a port, bind receivers and send it in a message elsewhere |
|
|
367 | in one go: |
|
|
368 | |
|
|
369 | snd $otherport, reply => |
|
|
370 | rcv port, |
|
|
371 | msg1 => sub { ...; 0 }, |
|
|
372 | ... |
|
|
373 | ; |
|
|
374 | |
|
|
375 | =cut |
|
|
376 | |
|
|
377 | sub rcv($@) { |
|
|
378 | my $port = shift; |
|
|
379 | my ($noderef, $portid) = split /#/, $port, 2; |
|
|
380 | |
|
|
381 | ($NODE{$noderef} || add_node $noderef) == $NODE{""} |
|
|
382 | or Carp::croak "$port: rcv can only be called on local ports, caught"; |
|
|
383 | |
|
|
384 | if (@_ == 1) { |
|
|
385 | my $cb = shift; |
|
|
386 | delete $PORT_DATA{$portid}; |
|
|
387 | $PORT{$portid} = sub { |
|
|
388 | local $SELF = $port; |
|
|
389 | eval { |
|
|
390 | &$cb |
|
|
391 | and kil $port; |
|
|
392 | }; |
|
|
393 | _self_die if $@; |
|
|
394 | }; |
|
|
395 | } else { |
|
|
396 | my $self = $PORT_DATA{$portid} ||= do { |
|
|
397 | my $self = bless { |
|
|
398 | id => $port, |
|
|
399 | }, "AnyEvent::MP::Port"; |
|
|
400 | |
|
|
401 | $PORT{$portid} = sub { |
|
|
402 | local $SELF = $port; |
|
|
403 | |
|
|
404 | eval { |
|
|
405 | for (@{ $self->{rc0}{$_[0]} }) { |
|
|
406 | $_ && &{$_->[0]} |
|
|
407 | && undef $_; |
|
|
408 | } |
|
|
409 | |
|
|
410 | for (@{ $self->{rcv}{$_[0]} }) { |
|
|
411 | $_ && [@_[1 .. @{$_->[1]}]] ~~ $_->[1] |
|
|
412 | && &{$_->[0]} |
|
|
413 | && undef $_; |
|
|
414 | } |
|
|
415 | |
|
|
416 | for (@{ $self->{any} }) { |
|
|
417 | $_ && [@_[0 .. $#{$_->[1]}]] ~~ $_->[1] |
|
|
418 | && &{$_->[0]} |
|
|
419 | && undef $_; |
|
|
420 | } |
|
|
421 | }; |
|
|
422 | _self_die if $@; |
|
|
423 | }; |
|
|
424 | |
|
|
425 | $self |
|
|
426 | }; |
|
|
427 | |
|
|
428 | "AnyEvent::MP::Port" eq ref $self |
|
|
429 | or Carp::croak "$port: rcv can only be called on message matching ports, caught"; |
|
|
430 | |
|
|
431 | while (@_) { |
|
|
432 | my ($match, $cb) = splice @_, 0, 2; |
|
|
433 | |
|
|
434 | if (!ref $match) { |
|
|
435 | push @{ $self->{rc0}{$match} }, [$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 { |
|
|
442 | push @{ $self->{any} }, [$cb, $match]; |
|
|
443 | } |
|
|
444 | } |
|
|
445 | } |
|
|
446 | |
|
|
447 | $port |
|
|
448 | } |
|
|
449 | |
|
|
450 | =item $closure = psub { BLOCK } |
|
|
451 | |
|
|
452 | Remembers C<$SELF> and creates a closure out of the BLOCK. When the |
|
|
453 | closure is executed, sets up the environment in the same way as in C<rcv> |
|
|
454 | callbacks, i.e. runtime errors will cause the port to get C<kil>ed. |
|
|
455 | |
|
|
456 | This is useful when you register callbacks from C<rcv> callbacks: |
|
|
457 | |
|
|
458 | rcv delayed_reply => sub { |
|
|
459 | my ($delay, @reply) = @_; |
|
|
460 | my $timer = AE::timer $delay, 0, psub { |
|
|
461 | snd @reply, $SELF; |
|
|
462 | }; |
|
|
463 | }; |
|
|
464 | |
|
|
465 | =cut |
|
|
466 | |
|
|
467 | sub psub(&) { |
|
|
468 | my $cb = shift; |
|
|
469 | |
|
|
470 | my $port = $SELF |
|
|
471 | or Carp::croak "psub can only be called from within rcv or psub callbacks, not"; |
|
|
472 | |
|
|
473 | sub { |
|
|
474 | local $SELF = $port; |
|
|
475 | |
|
|
476 | if (wantarray) { |
|
|
477 | my @res = eval { &$cb }; |
|
|
478 | _self_die if $@; |
|
|
479 | @res |
|
|
480 | } else { |
|
|
481 | my $res = eval { &$cb }; |
|
|
482 | _self_die if $@; |
|
|
483 | $res |
|
|
484 | } |
|
|
485 | } |
|
|
486 | } |
|
|
487 | |
123 | =item $guard = mon $portid, $cb->() |
488 | =item $guard = mon $port, $cb->(@reason) |
124 | |
489 | |
125 | =item $guard = mon $portid, $otherport |
490 | =item $guard = mon $port, $rcvport |
126 | |
491 | |
|
|
492 | =item $guard = mon $port |
|
|
493 | |
127 | =item $guard = mon $portid, $otherport, @msg |
494 | =item $guard = mon $port, $rcvport, @msg |
128 | |
495 | |
129 | Monitor the given port and call the given callback when the port is |
496 | Monitor the given port and do something when the port is killed, and |
130 | destroyed or connection to it's node is lost. |
497 | optionally return a guard that can be used to stop monitoring again. |
131 | |
498 | |
132 | #TODO |
499 | In the first form (callback), the callback is simply called with any |
|
|
500 | number of C<@reason> elements (no @reason means that the port was deleted |
|
|
501 | "normally"). Note also that I<< the callback B<must> never die >>, so use |
|
|
502 | C<eval> if unsure. |
|
|
503 | |
|
|
504 | In the second form (another port given), the other port (C<$rcvport) |
|
|
505 | will be C<kil>'ed with C<@reason>, iff a @reason was specified, i.e. on |
|
|
506 | "normal" kils nothing happens, while under all other conditions, the other |
|
|
507 | port is killed with the same reason. |
|
|
508 | |
|
|
509 | The third form (kill self) is the same as the second form, except that |
|
|
510 | C<$rvport> defaults to C<$SELF>. |
|
|
511 | |
|
|
512 | In the last form (message), a message of the form C<@msg, @reason> will be |
|
|
513 | C<snd>. |
|
|
514 | |
|
|
515 | As a rule of thumb, monitoring requests should always monitor a port from |
|
|
516 | a local port (or callback). The reason is that kill messages might get |
|
|
517 | lost, just like any other message. Another less obvious reason is that |
|
|
518 | even monitoring requests can get lost (for exmaple, when the connection |
|
|
519 | to the other node goes down permanently). When monitoring a port locally |
|
|
520 | these problems do not exist. |
|
|
521 | |
|
|
522 | Example: call a given callback when C<$port> is killed. |
|
|
523 | |
|
|
524 | mon $port, sub { warn "port died because of <@_>\n" }; |
|
|
525 | |
|
|
526 | Example: kill ourselves when C<$port> is killed abnormally. |
|
|
527 | |
|
|
528 | mon $port; |
|
|
529 | |
|
|
530 | Example: send us a restart message when another C<$port> is killed. |
|
|
531 | |
|
|
532 | mon $port, $self => "restart"; |
133 | |
533 | |
134 | =cut |
534 | =cut |
135 | |
535 | |
136 | sub mon { |
536 | sub mon { |
137 | my ($noderef, $port, $cb) = ((split /#/, shift, 2), shift); |
537 | my ($noderef, $port) = split /#/, shift, 2; |
138 | |
538 | |
139 | my $node = AnyEvent::MP::Base::add_node $noderef; |
539 | my $node = $NODE{$noderef} || add_node $noderef; |
140 | |
540 | |
141 | #TODO: ports must not be references |
541 | my $cb = @_ ? $_[0] : $SELF || Carp::croak 'mon: called with one argument only, but $SELF not set,'; |
142 | if (!ref $cb or "AnyEvent::MP::Port" eq ref $cb) { |
542 | |
|
|
543 | unless (ref $cb) { |
143 | if (@_) { |
544 | if (@_) { |
144 | # send a kill info message |
545 | # send a kill info message |
145 | my (@msg) = ($cb, @_); |
546 | my (@msg) = @_; |
146 | $cb = sub { snd @msg, @_ }; |
547 | $cb = sub { snd @msg, @_ }; |
147 | } else { |
548 | } else { |
148 | # simply kill other port |
549 | # simply kill other port |
149 | my $port = $cb; |
550 | my $port = $cb; |
150 | $cb = sub { kil $port, @_ }; |
551 | $cb = sub { kil $port, @_ if @_ }; |
151 | } |
552 | } |
152 | } |
553 | } |
153 | |
554 | |
154 | $node->monitor ($port, $cb); |
555 | $node->monitor ($port, $cb); |
155 | |
556 | |
… | |
… | |
176 | =cut |
577 | =cut |
177 | |
578 | |
178 | sub mon_guard { |
579 | sub mon_guard { |
179 | my ($port, @refs) = @_; |
580 | my ($port, @refs) = @_; |
180 | |
581 | |
|
|
582 | #TODO: mon-less form? |
|
|
583 | |
181 | mon $port, sub { 0 && @refs } |
584 | mon $port, sub { 0 && @refs } |
182 | } |
585 | } |
183 | |
586 | |
184 | =item $local_port = create_port |
587 | =item kil $port[, @reason] |
185 | |
588 | |
186 | Create a new local port object. See the next section for allowed methods. |
589 | Kill the specified port with the given C<@reason>. |
187 | |
590 | |
188 | =cut |
591 | If no C<@reason> is specified, then the port is killed "normally" (linked |
|
|
592 | ports will not be kileld, or even notified). |
189 | |
593 | |
190 | sub create_port { |
594 | Otherwise, linked ports get killed with the same reason (second form of |
191 | my $id = "$AnyEvent::MP::Base::UNIQ." . $AnyEvent::MP::Base::ID++; |
595 | C<mon>, see below). |
192 | |
596 | |
193 | my $self = bless { |
597 | Runtime errors while evaluating C<rcv> callbacks or inside C<psub> blocks |
194 | id => "$NODE#$id", |
598 | will be reported as reason C<< die => $@ >>. |
195 | }, "AnyEvent::MP::Port"; |
|
|
196 | |
599 | |
197 | $AnyEvent::MP::Base::PORT{$id} = sub { |
600 | Transport/communication errors are reported as C<< transport_error => |
198 | unshift @_, $self; |
601 | $message >>. |
199 | |
|
|
200 | for (@{ $self->{rc0}{$_[1]} }) { |
|
|
201 | $_ && &{$_->[0]} |
|
|
202 | && undef $_; |
|
|
203 | } |
|
|
204 | |
|
|
205 | for (@{ $self->{rcv}{$_[1]} }) { |
|
|
206 | $_ && [@_[1 .. @{$_->[1]}]] ~~ $_->[1] |
|
|
207 | && &{$_->[0]} |
|
|
208 | && undef $_; |
|
|
209 | } |
|
|
210 | |
|
|
211 | for (@{ $self->{any} }) { |
|
|
212 | $_ && [@_[0 .. $#{$_->[1]}]] ~~ $_->[1] |
|
|
213 | && &{$_->[0]} |
|
|
214 | && undef $_; |
|
|
215 | } |
|
|
216 | }; |
|
|
217 | |
|
|
218 | $self |
|
|
219 | } |
|
|
220 | |
|
|
221 | =item $portid = miniport { my @msg = @_; $finished } |
|
|
222 | |
|
|
223 | Creates a "mini port", that is, a very lightweight port without any |
|
|
224 | pattern matching behind it, and returns its ID. |
|
|
225 | |
|
|
226 | The block will be called for every message received on the port. When the |
|
|
227 | callback returns a true value its job is considered "done" and the port |
|
|
228 | will be destroyed. Otherwise it will stay alive. |
|
|
229 | |
|
|
230 | The message will be passed as-is, no extra argument (i.e. no port id) will |
|
|
231 | be passed to the callback. |
|
|
232 | |
|
|
233 | If you need the local port id in the callback, this works nicely: |
|
|
234 | |
|
|
235 | my $port; $port = miniport { |
|
|
236 | snd $otherport, reply => $port; |
|
|
237 | }; |
|
|
238 | |
|
|
239 | =cut |
|
|
240 | |
|
|
241 | sub miniport(&) { |
|
|
242 | my $cb = shift; |
|
|
243 | my $id = "$AnyEvent::MP::Base::UNIQ." . $AnyEvent::MP::Base::ID++; |
|
|
244 | |
|
|
245 | $AnyEvent::MP::Base::PORT{$id} = sub { |
|
|
246 | &$cb |
|
|
247 | and kil $id; |
|
|
248 | }; |
|
|
249 | |
|
|
250 | "$NODE#$id" |
|
|
251 | } |
|
|
252 | |
|
|
253 | package AnyEvent::MP::Port; |
|
|
254 | |
|
|
255 | =back |
|
|
256 | |
|
|
257 | =head1 METHODS FOR PORT OBJECTS |
|
|
258 | |
|
|
259 | =over 4 |
|
|
260 | |
|
|
261 | =item "$port" |
|
|
262 | |
|
|
263 | A port object stringifies to its port ID, so can be used directly for |
|
|
264 | C<snd> operations. |
|
|
265 | |
|
|
266 | =cut |
|
|
267 | |
|
|
268 | use overload |
|
|
269 | '""' => sub { $_[0]{id} }, |
|
|
270 | fallback => 1; |
|
|
271 | |
|
|
272 | sub TO_JSON { $_[0]{id} } |
|
|
273 | |
|
|
274 | =item $port->rcv (type => $callback->($port, @msg)) |
|
|
275 | |
|
|
276 | =item $port->rcv ($smartmatch => $callback->($port, @msg)) |
|
|
277 | |
|
|
278 | =item $port->rcv ([$smartmatch...] => $callback->($port, @msg)) |
|
|
279 | |
|
|
280 | Register a callback on the given port. |
|
|
281 | |
|
|
282 | The callback has to return a true value when its work is done, after |
|
|
283 | which is will be removed, or a false value in which case it will stay |
|
|
284 | registered. |
|
|
285 | |
|
|
286 | If the match is an array reference, then it will be matched against the |
|
|
287 | first elements of the message, otherwise only the first element is being |
|
|
288 | matched. |
|
|
289 | |
|
|
290 | Any element in the match that is specified as C<_any_> (a function |
|
|
291 | exported by this module) matches any single element of the message. |
|
|
292 | |
|
|
293 | While not required, it is highly recommended that the first matching |
|
|
294 | element is a string identifying the message. The one-string-only match is |
|
|
295 | also the most efficient match (by far). |
|
|
296 | |
|
|
297 | =cut |
|
|
298 | |
|
|
299 | sub rcv($@) { |
|
|
300 | my ($self, $match, $cb) = @_; |
|
|
301 | |
|
|
302 | if (!ref $match) { |
|
|
303 | push @{ $self->{rc0}{$match} }, [$cb]; |
|
|
304 | } elsif (("ARRAY" eq ref $match && !ref $match->[0])) { |
|
|
305 | my ($type, @match) = @$match; |
|
|
306 | @match |
|
|
307 | ? push @{ $self->{rcv}{$match->[0]} }, [$cb, \@match] |
|
|
308 | : push @{ $self->{rc0}{$match->[0]} }, [$cb]; |
|
|
309 | } else { |
|
|
310 | push @{ $self->{any} }, [$cb, $match]; |
|
|
311 | } |
|
|
312 | } |
|
|
313 | |
|
|
314 | =item $port->register ($name) |
|
|
315 | |
|
|
316 | Registers the given port under the well known name C<$name>. If the name |
|
|
317 | already exists it is replaced. |
|
|
318 | |
|
|
319 | A port can only be registered under one well known name. |
|
|
320 | |
|
|
321 | =cut |
|
|
322 | |
|
|
323 | sub register { |
|
|
324 | my ($self, $name) = @_; |
|
|
325 | |
|
|
326 | $self->{wkname} = $name; |
|
|
327 | $AnyEvent::MP::Base::WKP{$name} = "$self"; |
|
|
328 | } |
|
|
329 | |
|
|
330 | =item $port->destroy |
|
|
331 | |
|
|
332 | Explicitly destroy/remove/nuke/vaporise the port. |
|
|
333 | |
|
|
334 | Ports are normally kept alive by their mere existance alone, and need to |
|
|
335 | be destroyed explicitly. |
|
|
336 | |
|
|
337 | =cut |
|
|
338 | |
|
|
339 | sub destroy { |
|
|
340 | my ($self) = @_; |
|
|
341 | |
|
|
342 | delete $AnyEvent::MP::Base::WKP{ $self->{wkname} }; |
|
|
343 | |
|
|
344 | AnyEvent::MP::Base::kil $self->{id}; |
|
|
345 | } |
|
|
346 | |
|
|
347 | =back |
|
|
348 | |
|
|
349 | =head1 FUNCTIONS FOR NODES |
|
|
350 | |
|
|
351 | =over 4 |
|
|
352 | |
|
|
353 | =item mon $noderef, $callback->($noderef, $status, $) |
|
|
354 | |
|
|
355 | Monitors the given noderef. |
|
|
356 | |
|
|
357 | =item become_public endpoint... |
|
|
358 | |
|
|
359 | Tells the node to become a public node, i.e. reachable from other nodes. |
|
|
360 | |
|
|
361 | If no arguments are given, or the first argument is C<undef>, then |
|
|
362 | AnyEvent::MP tries to bind on port C<4040> on all IP addresses that the |
|
|
363 | local nodename resolves to. |
|
|
364 | |
|
|
365 | Otherwise the first argument must be an array-reference with transport |
|
|
366 | endpoints ("ip:port", "hostname:port") or port numbers (in which case the |
|
|
367 | local nodename is used as hostname). The endpoints are all resolved and |
|
|
368 | will become the node reference. |
|
|
369 | |
|
|
370 | =cut |
|
|
371 | |
602 | |
372 | =back |
603 | =back |
373 | |
604 | |
374 | =head1 NODE MESSAGES |
605 | =head1 NODE MESSAGES |
375 | |
606 | |
376 | Nodes understand the following messages sent to them. Many of them take |
607 | Nodes understand the following messages sent to them. Many of them take |
377 | arguments called C<@reply>, which will simply be used to compose a reply |
608 | arguments called C<@reply>, which will simply be used to compose a reply |
378 | message - C<$reply[0]> is the port to reply to, C<$reply[1]> the type and |
609 | message - C<$reply[0]> is the port to reply to, C<$reply[1]> the type and |
379 | the remaining arguments are simply the message data. |
610 | the remaining arguments are simply the message data. |
380 | |
611 | |
|
|
612 | While other messages exist, they are not public and subject to change. |
|
|
613 | |
381 | =over 4 |
614 | =over 4 |
382 | |
615 | |
383 | =cut |
616 | =cut |
384 | |
617 | |
385 | =item wkp => $name, @reply |
618 | =item lookup => $name, @reply |
386 | |
619 | |
387 | Replies with the port ID of the specified well-known port, or C<undef>. |
620 | Replies with the port ID of the specified well-known port, or C<undef>. |
388 | |
621 | |
389 | =item devnull => ... |
622 | =item devnull => ... |
390 | |
623 | |
… | |
… | |
413 | snd $NODE, time => $myport, timereply => 1, 2; |
646 | snd $NODE, time => $myport, timereply => 1, 2; |
414 | # => snd $myport, timereply => 1, 2, <time> |
647 | # => snd $myport, timereply => 1, 2, <time> |
415 | |
648 | |
416 | =back |
649 | =back |
417 | |
650 | |
|
|
651 | =head1 AnyEvent::MP vs. Distributed Erlang |
|
|
652 | |
|
|
653 | AnyEvent::MP got lots of its ideas from distributed Erlang (Erlang node |
|
|
654 | == aemp node, Erlang process == aemp port), so many of the documents and |
|
|
655 | programming techniques employed by Erlang apply to AnyEvent::MP. Here is a |
|
|
656 | sample: |
|
|
657 | |
|
|
658 | http://www.Erlang.se/doc/programming_rules.shtml |
|
|
659 | http://Erlang.org/doc/getting_started/part_frame.html # chapters 3 and 4 |
|
|
660 | http://Erlang.org/download/Erlang-book-part1.pdf # chapters 5 and 6 |
|
|
661 | http://Erlang.org/download/armstrong_thesis_2003.pdf # chapters 4 and 5 |
|
|
662 | |
|
|
663 | Despite the similarities, there are also some important differences: |
|
|
664 | |
|
|
665 | =over 4 |
|
|
666 | |
|
|
667 | =item * Node references contain the recipe on how to contact them. |
|
|
668 | |
|
|
669 | Erlang relies on special naming and DNS to work everywhere in the |
|
|
670 | same way. AEMP relies on each node knowing it's own address(es), with |
|
|
671 | convenience functionality. |
|
|
672 | |
|
|
673 | This means that AEMP requires a less tightly controlled environment at the |
|
|
674 | cost of longer node references and a slightly higher management overhead. |
|
|
675 | |
|
|
676 | =item * Erlang uses processes and a mailbox, AEMP does not queue. |
|
|
677 | |
|
|
678 | Erlang uses processes that selctively receive messages, and therefore |
|
|
679 | needs a queue. AEMP is event based, queuing messages would serve no useful |
|
|
680 | purpose. |
|
|
681 | |
|
|
682 | (But see L<Coro::MP> for a more Erlang-like process model on top of AEMP). |
|
|
683 | |
|
|
684 | =item * Erlang sends are synchronous, AEMP sends are asynchronous. |
|
|
685 | |
|
|
686 | Sending messages in Erlang is synchronous and blocks the process. AEMP |
|
|
687 | sends are immediate, connection establishment is handled in the |
|
|
688 | background. |
|
|
689 | |
|
|
690 | =item * Erlang can silently lose messages, AEMP cannot. |
|
|
691 | |
|
|
692 | 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, |
|
|
694 | and c, and the other side only receives messages a and c). |
|
|
695 | |
|
|
696 | AEMP guarantees correct ordering, and the guarantee that there are no |
|
|
697 | holes in the message sequence. |
|
|
698 | |
|
|
699 | =item * In Erlang, processes can be declared dead and later be found to be |
|
|
700 | alive. |
|
|
701 | |
|
|
702 | In Erlang it can happen that a monitored process is declared dead and |
|
|
703 | linked processes get killed, but later it turns out that the process is |
|
|
704 | still alive - and can receive messages. |
|
|
705 | |
|
|
706 | In AEMP, when port monitoring detects a port as dead, then that port will |
|
|
707 | 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. |
|
|
709 | |
|
|
710 | =item * Erlang can send messages to the wrong port, AEMP does not. |
|
|
711 | |
|
|
712 | In Erlang it is quite possible that a node that restarts reuses a process |
|
|
713 | ID known to other nodes for a completely different process, causing |
|
|
714 | messages destined for that process to end up in an unrelated process. |
|
|
715 | |
|
|
716 | 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. |
|
|
718 | |
|
|
719 | =item * Erlang uses unprotected connections, AEMP uses secure |
|
|
720 | authentication and can use TLS. |
|
|
721 | |
|
|
722 | AEMP can use a proven protocol - SSL/TLS - to protect connections and |
|
|
723 | securely authenticate nodes. |
|
|
724 | |
|
|
725 | =item * The AEMP protocol is optimised for both text-based and binary |
|
|
726 | communications. |
|
|
727 | |
|
|
728 | The AEMP protocol, unlike the Erlang protocol, supports both |
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|
729 | language-independent text-only protocols (good for debugging) and binary, |
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|
730 | language-specific serialisers (e.g. Storable). |
|
|
731 | |
|
|
732 | It has also been carefully designed to be implementable in other languages |
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|
733 | with a minimum of work while gracefully degrading fucntionality to make the |
|
|
734 | protocol simple. |
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|
735 | |
|
|
736 | =item * AEMP has more flexible monitoring options than Erlang. |
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|
737 | |
|
|
738 | In Erlang, you can chose to receive I<all> exit signals as messages |
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|
739 | or I<none>, there is no in-between, so monitoring single processes is |
|
|
740 | difficult to implement. Monitoring in AEMP is more flexible than in |
|
|
741 | Erlang, as one can choose between automatic kill, exit message or callback |
|
|
742 | on a per-process basis. |
|
|
743 | |
|
|
744 | =item * Erlang tries to hide remote/local connections, AEMP does not. |
|
|
745 | |
|
|
746 | Monitoring in Erlang is not an indicator of process death/crashes, |
|
|
747 | as linking is (except linking is unreliable in Erlang). |
|
|
748 | |
|
|
749 | In AEMP, you don't "look up" registered port names or send to named ports |
|
|
750 | that might or might not be persistent. Instead, you normally spawn a port |
|
|
751 | on the remote node. The init function monitors the you, and you monitor |
|
|
752 | the remote port. Since both monitors are local to the node, they are much |
|
|
753 | more reliable. |
|
|
754 | |
|
|
755 | This also saves round-trips and avoids sending messages to the wrong port |
|
|
756 | (hard to do in Erlang). |
|
|
757 | |
|
|
758 | =back |
|
|
759 | |
418 | =head1 SEE ALSO |
760 | =head1 SEE ALSO |
419 | |
761 | |
420 | L<AnyEvent>. |
762 | L<AnyEvent>. |
421 | |
763 | |
422 | =head1 AUTHOR |
764 | =head1 AUTHOR |