… | |
… | |
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 |
|
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10 | $NODE # contains this node identifier |
9 | $NODE # contains this node's noderef |
|
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10 | NODE # returns this node's noderef |
|
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11 | NODE $port # returns the noderef of the port |
11 | |
12 | |
12 | snd $port, type => data...; |
13 | snd $port, type => data...; |
|
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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 }; |
… | |
… | |
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 | # linking two ports, so they both crash together |
|
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29 | lnk $port1, $port2; |
|
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30 | |
|
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31 | # monitoring |
|
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32 | mon $port, $cb->(@msg) # callback is invoked on death |
|
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33 | mon $port, $otherport # kill otherport on abnormal death |
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34 | mon $port, $otherport, @msg # send message on death |
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35 | |
25 | =head1 DESCRIPTION |
36 | =head1 DESCRIPTION |
26 | |
37 | |
27 | This module (-family) implements a simple message passing framework. |
38 | This module (-family) implements a simple message passing framework. |
28 | |
39 | |
29 | Despite its simplicity, you can securely message other processes running |
40 | Despite its simplicity, you can securely message other processes running |
30 | on the same or other hosts. |
41 | on the same or other hosts. |
31 | |
42 | |
|
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43 | For an introduction to this module family, see the L<AnyEvent::MP::Intro> |
|
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44 | manual page. |
|
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45 | |
32 | At the moment, this module family is severly brokena nd underdocumented, |
46 | 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 - |
47 | so do not use. This was uploaded mainly to reserve the CPAN namespace - |
34 | stay tuned! |
48 | stay tuned! The basic API should be finished, however. |
35 | |
49 | |
36 | =head1 CONCEPTS |
50 | =head1 CONCEPTS |
37 | |
51 | |
38 | =over 4 |
52 | =over 4 |
39 | |
53 | |
40 | =item port |
54 | =item port |
41 | |
55 | |
42 | A port is something you can send messages to with the C<snd> function, and |
56 | 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 |
57 | |
44 | messages they match, messages will not be queued. |
58 | Some ports allow you to register C<rcv> handlers that can match specific |
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59 | messages. All C<rcv> handlers will receive messages they match, messages |
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60 | will not be queued. |
45 | |
61 | |
46 | =item port id - C<noderef#portname> |
62 | =item port id - C<noderef#portname> |
47 | |
63 | |
48 | A port id is always the noderef, a hash-mark (C<#>) as separator, followed |
64 | 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). |
65 | separator, and a port name (a printable string of unspecified format). An |
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66 | exception is the the node port, whose ID is identical to its node |
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67 | reference. |
50 | |
68 | |
51 | =item node |
69 | =item node |
52 | |
70 | |
53 | A node is a single process containing at least one port - the node |
71 | 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, |
72 | port. You can send messages to node ports to find existing ports or to |
55 | among other things. |
73 | create new ports, among other things. |
56 | |
74 | |
57 | Initially, nodes are either private (single-process only) or hidden |
75 | Nodes are either private (single-process only), slaves (connected to a |
58 | (connected to a master node only). Only when they epxlicitly "become |
76 | master node only) or public nodes (connectable from unrelated nodes). |
59 | public" can you send them messages from unrelated other nodes. |
|
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60 | |
77 | |
61 | =item noderef - C<host:port,host:port...>, C<id@noderef>, C<id> |
78 | =item noderef - C<host:port,host:port...>, C<id@noderef>, C<id> |
62 | |
79 | |
63 | A noderef is a string that either uniquely identifies a given node (for |
80 | 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 |
81 | private and slave nodes), or contains a recipe on how to reach a given |
65 | node (for public nodes). |
82 | node (for public nodes). |
66 | |
83 | |
|
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84 | This recipe is simply a comma-separated list of C<address:port> pairs (for |
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85 | TCP/IP, other protocols might look different). |
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86 | |
|
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87 | Node references come in two flavours: resolved (containing only numerical |
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88 | addresses) or unresolved (where hostnames are used instead of addresses). |
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89 | |
|
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90 | Before using an unresolved node reference in a message you first have to |
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91 | resolve it. |
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92 | |
67 | =back |
93 | =back |
68 | |
94 | |
69 | =head1 VARIABLES/FUNCTIONS |
95 | =head1 VARIABLES/FUNCTIONS |
70 | |
96 | |
71 | =over 4 |
97 | =over 4 |
… | |
… | |
82 | |
108 | |
83 | use AE (); |
109 | use AE (); |
84 | |
110 | |
85 | use base "Exporter"; |
111 | use base "Exporter"; |
86 | |
112 | |
87 | our $VERSION = '0.02'; |
113 | our $VERSION = '0.1'; |
88 | our @EXPORT = qw( |
114 | our @EXPORT = qw( |
89 | NODE $NODE $PORT snd rcv _any_ |
115 | NODE $NODE *SELF node_of _any_ |
90 | create_port create_port_on |
116 | resolve_node initialise_node |
91 | become_slave become_public |
117 | snd rcv mon kil reg psub |
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118 | port |
92 | ); |
119 | ); |
93 | |
120 | |
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121 | our $SELF; |
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122 | |
|
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123 | sub _self_die() { |
|
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124 | my $msg = $@; |
|
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125 | $msg =~ s/\n+$// unless ref $msg; |
|
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126 | kil $SELF, die => $msg; |
|
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127 | } |
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128 | |
94 | =item NODE / $NODE |
129 | =item $thisnode = NODE / $NODE |
95 | |
130 | |
96 | The C<NODE ()> function and the C<$NODE> variable contain the noderef of |
131 | 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 |
132 | 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. |
133 | to C<become_public> or C<become_slave>, after which all local port |
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134 | identifiers become invalid. |
99 | |
135 | |
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136 | =item $noderef = node_of $port |
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137 | |
|
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138 | Extracts and returns the noderef from a portid or a noderef. |
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139 | |
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140 | =item initialise_node $noderef, $seednode, $seednode... |
|
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141 | |
|
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142 | =item initialise_node "slave/", $master, $master... |
|
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143 | |
|
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144 | Before a node can talk to other nodes on the network it has to initialise |
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145 | itself - the minimum a node needs to know is it's own name, and optionally |
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146 | it should know the noderefs of some other nodes in the network. |
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147 | |
|
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148 | This function initialises a node - it must be called exactly once (or |
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149 | never) before calling other AnyEvent::MP functions. |
|
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150 | |
|
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151 | All arguments are noderefs, which can be either resolved or unresolved. |
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152 | |
|
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153 | There are two types of networked nodes, public nodes and slave nodes: |
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154 | |
|
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155 | =over 4 |
|
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156 | |
|
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157 | =item public nodes |
|
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158 | |
|
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159 | For public nodes, C<$noderef> must either be a (possibly unresolved) |
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160 | noderef, in which case it will be resolved, or C<undef> (or missing), in |
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161 | which case the noderef will be guessed. |
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162 | |
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163 | Afterwards, the node will bind itself on all endpoints and try to connect |
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164 | to all additional C<$seednodes> that are specified. Seednodes are optional |
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165 | and can be used to quickly bootstrap the node into an existing network. |
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166 | |
|
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167 | =item slave nodes |
|
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168 | |
|
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169 | When the C<$noderef> is the special string C<slave/>, then the node will |
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170 | become a slave node. Slave nodes cannot be contacted from outside and will |
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171 | route most of their traffic to the master node that they attach to. |
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172 | |
|
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173 | At least one additional noderef is required: The node will try to connect |
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174 | to all of them and will become a slave attached to the first node it can |
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175 | successfully connect to. |
|
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176 | |
|
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177 | =back |
|
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178 | |
|
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179 | This function will block until all nodes have been resolved and, for slave |
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180 | nodes, until it has successfully established a connection to a master |
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181 | server. |
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182 | |
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183 | Example: become a public node listening on the default node. |
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184 | |
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185 | initialise_node; |
|
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186 | |
|
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187 | Example: become a public node, and try to contact some well-known master |
|
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188 | servers to become part of the network. |
|
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189 | |
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190 | initialise_node undef, "master1", "master2"; |
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191 | |
|
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192 | Example: become a public node listening on port C<4041>. |
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193 | |
|
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194 | initialise_node 4041; |
|
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195 | |
|
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196 | Example: become a public node, only visible on localhost port 4044. |
|
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197 | |
|
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198 | initialise_node "locahost:4044"; |
|
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199 | |
|
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200 | Example: become a slave node to any of the specified master servers. |
|
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201 | |
|
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202 | initialise_node "slave/", "master1", "192.168.13.17", "mp.example.net"; |
|
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203 | |
|
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204 | =item $cv = resolve_node $noderef |
|
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205 | |
|
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206 | Takes an unresolved node reference that may contain hostnames and |
|
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207 | abbreviated IDs, resolves all of them and returns a resolved node |
|
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208 | reference. |
|
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209 | |
|
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210 | In addition to C<address:port> pairs allowed in resolved noderefs, the |
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211 | following forms are supported: |
|
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212 | |
|
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213 | =over 4 |
|
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214 | |
|
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215 | =item the empty string |
|
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216 | |
|
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217 | An empty-string component gets resolved as if the default port (4040) was |
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218 | specified. |
|
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219 | |
|
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220 | =item naked port numbers (e.g. C<1234>) |
|
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221 | |
|
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222 | These are resolved by prepending the local nodename and a colon, to be |
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223 | further resolved. |
|
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224 | |
|
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225 | =item hostnames (e.g. C<localhost:1234>, C<localhost>) |
|
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226 | |
|
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227 | These are resolved by using AnyEvent::DNS to resolve them, optionally |
|
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228 | looking up SRV records for the C<aemp=4040> port, if no port was |
|
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229 | specified. |
|
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230 | |
|
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231 | =back |
|
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232 | |
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233 | =item $SELF |
|
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234 | |
|
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235 | Contains the current port id while executing C<rcv> callbacks or C<psub> |
|
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236 | blocks. |
|
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237 | |
|
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238 | =item SELF, %SELF, @SELF... |
|
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239 | |
|
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240 | Due to some quirks in how perl exports variables, it is impossible to |
|
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241 | just export C<$SELF>, all the symbols called C<SELF> are exported by this |
|
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242 | module, but only C<$SELF> is currently used. |
|
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243 | |
100 | =item snd $portid, type => @data |
244 | =item snd $port, type => @data |
101 | |
245 | |
102 | =item snd $portid, @msg |
246 | =item snd $port, @msg |
103 | |
247 | |
104 | Send the given message to the given port ID, which can identify either |
248 | Send the given message to the given port ID, which can identify either |
105 | a local or a remote port, and can be either a string or soemthignt hat |
249 | a local or a remote port, and can be either a string or soemthignt hat |
106 | stringifies a sa port ID (such as a port object :). |
250 | stringifies a sa port ID (such as a port object :). |
107 | |
251 | |
… | |
… | |
117 | JSON is used, then only strings, numbers and arrays and hashes consisting |
261 | 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 |
262 | 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 |
263 | that Storable can serialise and deserialise is allowed, and for the local |
120 | node, anything can be passed. |
264 | node, anything can be passed. |
121 | |
265 | |
122 | =item $local_port = create_port |
266 | =item $local_port = port |
123 | |
267 | |
124 | Create a new local port object. See the next section for allowed methods. |
268 | Create a new local port object that can be used either as a pattern |
|
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269 | matching port ("full port") or a single-callback port ("miniport"), |
|
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270 | depending on how C<rcv> callbacks are bound to the object. |
125 | |
271 | |
126 | =cut |
272 | =item $port = port { my @msg = @_; $finished } |
127 | |
273 | |
128 | sub create_port { |
274 | Creates a "miniport", that is, a very lightweight port without any pattern |
129 | my $id = "$AnyEvent::MP::Base::UNIQ." . ++$AnyEvent::MP::Base::ID; |
275 | matching behind it, and returns its ID. Semantically the same as creating |
|
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276 | a port and calling C<rcv $port, $callback> on it. |
130 | |
277 | |
131 | my $self = bless { |
278 | The block will be called for every message received on the port. When the |
132 | id => "$NODE#$id", |
279 | callback returns a true value its job is considered "done" and the port |
133 | names => [$id], |
280 | will be destroyed. Otherwise it will stay alive. |
134 | }, "AnyEvent::MP::Port"; |
|
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135 | |
281 | |
136 | $AnyEvent::MP::Base::PORT{$id} = sub { |
282 | The message will be passed as-is, no extra argument (i.e. no port id) will |
137 | unshift @_, $self; |
283 | be passed to the callback. |
138 | |
284 | |
139 | for (@{ $self->{rc0}{$_[1]} }) { |
285 | If you need the local port id in the callback, this works nicely: |
140 | $_ && &{$_->[0]} |
|
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141 | && undef $_; |
|
|
142 | } |
|
|
143 | |
286 | |
144 | for (@{ $self->{rcv}{$_[1]} }) { |
287 | my $port; $port = port { |
145 | $_ && [@_[1 .. @{$_->[1]}]] ~~ $_->[1] |
288 | snd $otherport, reply => $port; |
146 | && &{$_->[0]} |
|
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147 | && undef $_; |
|
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148 | } |
|
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149 | |
|
|
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 | } |
|
|
155 | }; |
289 | }; |
156 | |
290 | |
157 | $self |
291 | =cut |
|
|
292 | |
|
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293 | sub rcv($@); |
|
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294 | |
|
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295 | sub port(;&) { |
|
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296 | my $id = "$UNIQ." . $ID++; |
|
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297 | my $port = "$NODE#$id"; |
|
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298 | |
|
|
299 | if (@_) { |
|
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300 | rcv $port, shift; |
|
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301 | } else { |
|
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302 | $PORT{$id} = sub { }; # nop |
|
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303 | } |
|
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304 | |
|
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305 | $port |
158 | } |
306 | } |
159 | |
307 | |
160 | package AnyEvent::MP::Port; |
308 | =item reg $port, $name |
161 | |
309 | |
162 | =back |
310 | Registers the given port under the name C<$name>. If the name already |
|
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311 | exists it is replaced. |
163 | |
312 | |
164 | =head1 METHODS FOR PORT OBJECTS |
313 | A port can only be registered under one well known name. |
165 | |
314 | |
166 | =over 4 |
315 | A port automatically becomes unregistered when it is killed. |
167 | |
316 | |
168 | =item "$port" |
|
|
169 | |
|
|
170 | A port object stringifies to its port ID, so can be used directly for |
|
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171 | C<snd> operations. |
|
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172 | |
|
|
173 | =cut |
317 | =cut |
174 | |
318 | |
175 | use overload |
319 | sub reg(@) { |
176 | '""' => sub { $_[0]{id} }, |
320 | my ($port, $name) = @_; |
177 | fallback => 1; |
|
|
178 | |
321 | |
179 | =item $port->rcv (type => $callback->($port, @msg)) |
322 | $REG{$name} = $port; |
|
|
323 | } |
180 | |
324 | |
181 | =item $port->rcv ($smartmatch => $callback->($port, @msg)) |
325 | =item rcv $port, $callback->(@msg) |
182 | |
326 | |
|
|
327 | Replaces the callback on the specified miniport (after converting it to |
|
|
328 | one if required). |
|
|
329 | |
|
|
330 | =item rcv $port, tagstring => $callback->(@msg), ... |
|
|
331 | |
|
|
332 | =item rcv $port, $smartmatch => $callback->(@msg), ... |
|
|
333 | |
183 | =item $port->rcv ([$smartmatch...] => $callback->($port, @msg)) |
334 | =item rcv $port, [$smartmatch...] => $callback->(@msg), ... |
184 | |
335 | |
185 | Register a callback on the given port. |
336 | Register callbacks to be called on matching messages on the given full |
|
|
337 | port (after converting it to one if required). |
186 | |
338 | |
187 | The callback has to return a true value when its work is done, after |
339 | The callback has to return a true value when its work is done, after |
188 | which is will be removed, or a false value in which case it will stay |
340 | which is will be removed, or a false value in which case it will stay |
189 | registered. |
341 | registered. |
190 | |
342 | |
|
|
343 | The global C<$SELF> (exported by this module) contains C<$port> while |
|
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344 | executing the callback. |
|
|
345 | |
|
|
346 | Runtime errors wdurign callback execution will result in the port being |
|
|
347 | C<kil>ed. |
|
|
348 | |
191 | If the match is an array reference, then it will be matched against the |
349 | If the match is an array reference, then it will be matched against the |
192 | first elements of the message, otherwise only the first element is being |
350 | first elements of the message, otherwise only the first element is being |
193 | matched. |
351 | matched. |
194 | |
352 | |
195 | Any element in the match that is specified as C<_any_> (a function |
353 | Any element in the match that is specified as C<_any_> (a function |
… | |
… | |
200 | also the most efficient match (by far). |
358 | also the most efficient match (by far). |
201 | |
359 | |
202 | =cut |
360 | =cut |
203 | |
361 | |
204 | sub rcv($@) { |
362 | sub rcv($@) { |
205 | my ($self, $match, $cb) = @_; |
363 | my $port = shift; |
|
|
364 | my ($noderef, $portid) = split /#/, $port, 2; |
206 | |
365 | |
207 | if (!ref $match) { |
366 | ($NODE{$noderef} || add_node $noderef) == $NODE{""} |
208 | push @{ $self->{rc0}{$match} }, [$cb]; |
367 | or Carp::croak "$port: rcv can only be called on local ports, caught"; |
209 | } elsif (("ARRAY" eq ref $match && !ref $match->[0])) { |
368 | |
210 | my ($type, @match) = @$match; |
369 | if (@_ == 1) { |
211 | @match |
370 | my $cb = shift; |
212 | ? push @{ $self->{rcv}{$match->[0]} }, [$cb, \@match] |
371 | delete $PORT_DATA{$portid}; |
213 | : push @{ $self->{rc0}{$match->[0]} }, [$cb]; |
372 | $PORT{$portid} = sub { |
|
|
373 | local $SELF = $port; |
|
|
374 | eval { |
|
|
375 | &$cb |
|
|
376 | and kil $port; |
|
|
377 | }; |
|
|
378 | _self_die if $@; |
|
|
379 | }; |
214 | } else { |
380 | } else { |
|
|
381 | my $self = $PORT_DATA{$portid} ||= do { |
|
|
382 | my $self = bless { |
|
|
383 | id => $port, |
|
|
384 | }, "AnyEvent::MP::Port"; |
|
|
385 | |
|
|
386 | $PORT{$portid} = sub { |
|
|
387 | local $SELF = $port; |
|
|
388 | |
|
|
389 | eval { |
|
|
390 | for (@{ $self->{rc0}{$_[0]} }) { |
|
|
391 | $_ && &{$_->[0]} |
|
|
392 | && undef $_; |
|
|
393 | } |
|
|
394 | |
|
|
395 | for (@{ $self->{rcv}{$_[0]} }) { |
|
|
396 | $_ && [@_[1 .. @{$_->[1]}]] ~~ $_->[1] |
|
|
397 | && &{$_->[0]} |
|
|
398 | && undef $_; |
|
|
399 | } |
|
|
400 | |
|
|
401 | for (@{ $self->{any} }) { |
|
|
402 | $_ && [@_[0 .. $#{$_->[1]}]] ~~ $_->[1] |
|
|
403 | && &{$_->[0]} |
|
|
404 | && undef $_; |
|
|
405 | } |
|
|
406 | }; |
|
|
407 | _self_die if $@; |
|
|
408 | }; |
|
|
409 | |
|
|
410 | $self |
|
|
411 | }; |
|
|
412 | |
|
|
413 | "AnyEvent::MP::Port" eq ref $self |
|
|
414 | or Carp::croak "$port: rcv can only be called on message matching ports, caught"; |
|
|
415 | |
|
|
416 | while (@_) { |
|
|
417 | my ($match, $cb) = splice @_, 0, 2; |
|
|
418 | |
|
|
419 | if (!ref $match) { |
|
|
420 | push @{ $self->{rc0}{$match} }, [$cb]; |
|
|
421 | } elsif (("ARRAY" eq ref $match && !ref $match->[0])) { |
|
|
422 | my ($type, @match) = @$match; |
|
|
423 | @match |
|
|
424 | ? push @{ $self->{rcv}{$match->[0]} }, [$cb, \@match] |
|
|
425 | : push @{ $self->{rc0}{$match->[0]} }, [$cb]; |
|
|
426 | } else { |
215 | push @{ $self->{any} }, [$cb, $match]; |
427 | push @{ $self->{any} }, [$cb, $match]; |
|
|
428 | } |
|
|
429 | } |
|
|
430 | } |
|
|
431 | |
|
|
432 | $port |
|
|
433 | } |
|
|
434 | |
|
|
435 | =item $closure = psub { BLOCK } |
|
|
436 | |
|
|
437 | Remembers C<$SELF> and creates a closure out of the BLOCK. When the |
|
|
438 | closure is executed, sets up the environment in the same way as in C<rcv> |
|
|
439 | callbacks, i.e. runtime errors will cause the port to get C<kil>ed. |
|
|
440 | |
|
|
441 | This is useful when you register callbacks from C<rcv> callbacks: |
|
|
442 | |
|
|
443 | rcv delayed_reply => sub { |
|
|
444 | my ($delay, @reply) = @_; |
|
|
445 | my $timer = AE::timer $delay, 0, psub { |
|
|
446 | snd @reply, $SELF; |
|
|
447 | }; |
|
|
448 | }; |
|
|
449 | |
|
|
450 | =cut |
|
|
451 | |
|
|
452 | sub psub(&) { |
|
|
453 | my $cb = shift; |
|
|
454 | |
|
|
455 | my $port = $SELF |
|
|
456 | or Carp::croak "psub can only be called from within rcv or psub callbacks, not"; |
|
|
457 | |
|
|
458 | sub { |
|
|
459 | local $SELF = $port; |
|
|
460 | |
|
|
461 | if (wantarray) { |
|
|
462 | my @res = eval { &$cb }; |
|
|
463 | _self_die if $@; |
|
|
464 | @res |
|
|
465 | } else { |
|
|
466 | my $res = eval { &$cb }; |
|
|
467 | _self_die if $@; |
|
|
468 | $res |
|
|
469 | } |
216 | } |
470 | } |
217 | } |
471 | } |
218 | |
472 | |
219 | =item $port->register ($name) |
473 | =item $guard = mon $port, $cb->(@reason) |
220 | |
474 | |
221 | Registers the given port under the well known name C<$name>. If the name |
475 | =item $guard = mon $port, $otherport |
222 | already exists it is replaced. |
|
|
223 | |
476 | |
224 | A port can only be registered under one well known name. |
477 | =item $guard = mon $port, $otherport, @msg |
225 | |
478 | |
226 | =cut |
479 | Monitor the given port and do something when the port is killed. |
227 | |
480 | |
228 | sub register { |
481 | In the first form, the callback is simply called with any number |
229 | my ($self, $name) = @_; |
482 | of C<@reason> elements (no @reason means that the port was deleted |
|
|
483 | "normally"). Note also that I<< the callback B<must> never die >>, so use |
|
|
484 | C<eval> if unsure. |
230 | |
485 | |
231 | $self->{wkname} = $name; |
486 | In the second form, the other port will be C<kil>'ed with C<@reason>, iff |
232 | $AnyEvent::MP::Base::WKP{$name} = "$self"; |
487 | a @reason was specified, i.e. on "normal" kils nothing happens, while |
|
|
488 | under all other conditions, the other port is killed with the same reason. |
|
|
489 | |
|
|
490 | In the last form, a message of the form C<@msg, @reason> will be C<snd>. |
|
|
491 | |
|
|
492 | Example: call a given callback when C<$port> is killed. |
|
|
493 | |
|
|
494 | mon $port, sub { warn "port died because of <@_>\n" }; |
|
|
495 | |
|
|
496 | Example: kill ourselves when C<$port> is killed abnormally. |
|
|
497 | |
|
|
498 | mon $port, $self; |
|
|
499 | |
|
|
500 | Example: send us a restart message another C<$port> is killed. |
|
|
501 | |
|
|
502 | mon $port, $self => "restart"; |
|
|
503 | |
|
|
504 | =cut |
|
|
505 | |
|
|
506 | sub mon { |
|
|
507 | my ($noderef, $port) = split /#/, shift, 2; |
|
|
508 | |
|
|
509 | my $node = $NODE{$noderef} || add_node $noderef; |
|
|
510 | |
|
|
511 | my $cb = shift; |
|
|
512 | |
|
|
513 | unless (ref $cb) { |
|
|
514 | if (@_) { |
|
|
515 | # send a kill info message |
|
|
516 | my (@msg) = ($cb, @_); |
|
|
517 | $cb = sub { snd @msg, @_ }; |
|
|
518 | } else { |
|
|
519 | # simply kill other port |
|
|
520 | my $port = $cb; |
|
|
521 | $cb = sub { kil $port, @_ if @_ }; |
|
|
522 | } |
|
|
523 | } |
|
|
524 | |
|
|
525 | $node->monitor ($port, $cb); |
|
|
526 | |
|
|
527 | defined wantarray |
|
|
528 | and AnyEvent::Util::guard { $node->unmonitor ($port, $cb) } |
233 | } |
529 | } |
234 | |
530 | |
235 | =item $port->destroy |
531 | =item $guard = mon_guard $port, $ref, $ref... |
236 | |
532 | |
237 | Explicitly destroy/remove/nuke/vaporise the port. |
533 | Monitors the given C<$port> and keeps the passed references. When the port |
|
|
534 | is killed, the references will be freed. |
238 | |
535 | |
239 | Ports are normally kept alive by there mere existance alone, and need to |
536 | Optionally returns a guard that will stop the monitoring. |
240 | be destroyed explicitly. |
|
|
241 | |
537 | |
242 | =cut |
538 | This function is useful when you create e.g. timers or other watchers and |
|
|
539 | want to free them when the port gets killed: |
243 | |
540 | |
244 | sub destroy { |
541 | $port->rcv (start => sub { |
245 | my ($self) = @_; |
542 | my $timer; $timer = mon_guard $port, AE::timer 1, 1, sub { |
|
|
543 | undef $timer if 0.9 < rand; |
|
|
544 | }); |
|
|
545 | }); |
246 | |
546 | |
247 | delete $AnyEvent::MP::Base::WKP{ $self->{wkname} }; |
547 | =cut |
248 | |
548 | |
249 | delete $AnyEvent::MP::Base::PORT{$_} |
549 | sub mon_guard { |
250 | for @{ $self->{names} }; |
550 | my ($port, @refs) = @_; |
|
|
551 | |
|
|
552 | mon $port, sub { 0 && @refs } |
251 | } |
553 | } |
252 | |
554 | |
253 | =back |
555 | =item lnk $port1, $port2 |
254 | |
556 | |
255 | =head1 FUNCTIONS FOR NODES |
557 | Link two ports. This is simply a shorthand for: |
256 | |
558 | |
257 | =over 4 |
559 | mon $port1, $port2; |
|
|
560 | mon $port2, $port1; |
258 | |
561 | |
259 | =item mon $noderef, $callback->($noderef, $status, $) |
562 | It means that if either one is killed abnormally, the other one gets |
|
|
563 | killed as well. |
260 | |
564 | |
261 | Monitors the given noderef. |
565 | =item kil $port[, @reason] |
262 | |
566 | |
263 | =item become_public endpoint... |
567 | Kill the specified port with the given C<@reason>. |
264 | |
568 | |
265 | Tells the node to become a public node, i.e. reachable from other nodes. |
569 | If no C<@reason> is specified, then the port is killed "normally" (linked |
|
|
570 | ports will not be kileld, or even notified). |
266 | |
571 | |
267 | If no arguments are given, or the first argument is C<undef>, then |
572 | Otherwise, linked ports get killed with the same reason (second form of |
268 | AnyEvent::MP tries to bind on port C<4040> on all IP addresses that the |
573 | C<mon>, see below). |
269 | local nodename resolves to. |
|
|
270 | |
574 | |
271 | Otherwise the first argument must be an array-reference with transport |
575 | Runtime errors while evaluating C<rcv> callbacks or inside C<psub> blocks |
272 | endpoints ("ip:port", "hostname:port") or port numbers (in which case the |
576 | will be reported as reason C<< die => $@ >>. |
273 | local nodename is used as hostname). The endpoints are all resolved and |
|
|
274 | will become the node reference. |
|
|
275 | |
577 | |
276 | =cut |
578 | Transport/communication errors are reported as C<< transport_error => |
|
|
579 | $message >>. |
277 | |
580 | |
278 | =back |
581 | =back |
279 | |
582 | |
280 | =head1 NODE MESSAGES |
583 | =head1 NODE MESSAGES |
281 | |
584 | |
282 | Nodes understand the following messages sent to them. Many of them take |
585 | Nodes understand the following messages sent to them. Many of them take |
283 | arguments called C<@reply>, which will simply be used to compose a reply |
586 | arguments called C<@reply>, which will simply be used to compose a reply |
284 | message - C<$reply[0]> is the port to reply to, C<$reply[1]> the type and |
587 | message - C<$reply[0]> is the port to reply to, C<$reply[1]> the type and |
285 | the remaining arguments are simply the message data. |
588 | the remaining arguments are simply the message data. |
286 | |
589 | |
|
|
590 | While other messages exist, they are not public and subject to change. |
|
|
591 | |
287 | =over 4 |
592 | =over 4 |
288 | |
593 | |
289 | =cut |
594 | =cut |
290 | |
595 | |
291 | =item wkp => $name, @reply |
596 | =item lookup => $name, @reply |
292 | |
597 | |
293 | Replies with the port ID of the specified well-known port, or C<undef>. |
598 | Replies with the port ID of the specified well-known port, or C<undef>. |
294 | |
599 | |
295 | =item devnull => ... |
600 | =item devnull => ... |
296 | |
601 | |
… | |
… | |
319 | snd $NODE, time => $myport, timereply => 1, 2; |
624 | snd $NODE, time => $myport, timereply => 1, 2; |
320 | # => snd $myport, timereply => 1, 2, <time> |
625 | # => snd $myport, timereply => 1, 2, <time> |
321 | |
626 | |
322 | =back |
627 | =back |
323 | |
628 | |
|
|
629 | =head1 AnyEvent::MP vs. Distributed Erlang |
|
|
630 | |
|
|
631 | AnyEvent::MP got lots of its ideas from distributed Erlang (Erlang node |
|
|
632 | == aemp node, Erlang process == aemp port), so many of the documents and |
|
|
633 | programming techniques employed by Erlang apply to AnyEvent::MP. Here is a |
|
|
634 | sample: |
|
|
635 | |
|
|
636 | http://www.Erlang.se/doc/programming_rules.shtml |
|
|
637 | http://Erlang.org/doc/getting_started/part_frame.html # chapters 3 and 4 |
|
|
638 | http://Erlang.org/download/Erlang-book-part1.pdf # chapters 5 and 6 |
|
|
639 | http://Erlang.org/download/armstrong_thesis_2003.pdf # chapters 4 and 5 |
|
|
640 | |
|
|
641 | Despite the similarities, there are also some important differences: |
|
|
642 | |
|
|
643 | =over 4 |
|
|
644 | |
|
|
645 | =item * Node references contain the recipe on how to contact them. |
|
|
646 | |
|
|
647 | Erlang relies on special naming and DNS to work everywhere in the |
|
|
648 | same way. AEMP relies on each node knowing it's own address(es), with |
|
|
649 | convenience functionality. |
|
|
650 | |
|
|
651 | This means that AEMP requires a less tightly controlled environment at the |
|
|
652 | cost of longer node references and a slightly higher management overhead. |
|
|
653 | |
|
|
654 | =item * Erlang uses processes and a mailbox, AEMP does not queue. |
|
|
655 | |
|
|
656 | Erlang uses processes that selctively receive messages, and therefore |
|
|
657 | needs a queue. AEMP is event based, queuing messages would serve no useful |
|
|
658 | purpose. |
|
|
659 | |
|
|
660 | (But see L<Coro::MP> for a more Erlang-like process model on top of AEMP). |
|
|
661 | |
|
|
662 | =item * Erlang sends are synchronous, AEMP sends are asynchronous. |
|
|
663 | |
|
|
664 | Sending messages in Erlang is synchronous and blocks the process. AEMP |
|
|
665 | sends are immediate, connection establishment is handled in the |
|
|
666 | background. |
|
|
667 | |
|
|
668 | =item * Erlang can silently lose messages, AEMP cannot. |
|
|
669 | |
|
|
670 | Erlang makes few guarantees on messages delivery - messages can get lost |
|
|
671 | without any of the processes realising it (i.e. you send messages a, b, |
|
|
672 | and c, and the other side only receives messages a and c). |
|
|
673 | |
|
|
674 | AEMP guarantees correct ordering, and the guarantee that there are no |
|
|
675 | holes in the message sequence. |
|
|
676 | |
|
|
677 | =item * In Erlang, processes can be declared dead and later be found to be |
|
|
678 | alive. |
|
|
679 | |
|
|
680 | In Erlang it can happen that a monitored process is declared dead and |
|
|
681 | linked processes get killed, but later it turns out that the process is |
|
|
682 | still alive - and can receive messages. |
|
|
683 | |
|
|
684 | In AEMP, when port monitoring detects a port as dead, then that port will |
|
|
685 | eventually be killed - it cannot happen that a node detects a port as dead |
|
|
686 | and then later sends messages to it, finding it is still alive. |
|
|
687 | |
|
|
688 | =item * Erlang can send messages to the wrong port, AEMP does not. |
|
|
689 | |
|
|
690 | In Erlang it is quite possible that a node that restarts reuses a process |
|
|
691 | ID known to other nodes for a completely different process, causing |
|
|
692 | messages destined for that process to end up in an unrelated process. |
|
|
693 | |
|
|
694 | AEMP never reuses port IDs, so old messages or old port IDs floating |
|
|
695 | around in the network will not be sent to an unrelated port. |
|
|
696 | |
|
|
697 | =item * Erlang uses unprotected connections, AEMP uses secure |
|
|
698 | authentication and can use TLS. |
|
|
699 | |
|
|
700 | AEMP can use a proven protocol - SSL/TLS - to protect connections and |
|
|
701 | securely authenticate nodes. |
|
|
702 | |
|
|
703 | =item * The AEMP protocol is optimised for both text-based and binary |
|
|
704 | communications. |
|
|
705 | |
|
|
706 | The AEMP protocol, unlike the Erlang protocol, supports both |
|
|
707 | language-independent text-only protocols (good for debugging) and binary, |
|
|
708 | language-specific serialisers (e.g. Storable). |
|
|
709 | |
|
|
710 | It has also been carefully designed to be implementable in other languages |
|
|
711 | with a minimum of work while gracefully degrading fucntionality to make the |
|
|
712 | protocol simple. |
|
|
713 | |
|
|
714 | =item * AEMP has more flexible monitoring options than Erlang. |
|
|
715 | |
|
|
716 | In Erlang, you can chose to receive I<all> exit signals as messages |
|
|
717 | or I<none>, there is no in-between, so monitoring single processes is |
|
|
718 | difficult to implement. Monitoring in AEMP is more flexible than in |
|
|
719 | Erlang, as one can choose between automatic kill, exit message or callback |
|
|
720 | on a per-process basis. |
|
|
721 | |
|
|
722 | =item * Erlang has different semantics for monitoring and linking, AEMP has the same. |
|
|
723 | |
|
|
724 | Monitoring in Erlang is not an indicator of process death/crashes, |
|
|
725 | as linking is (except linking is unreliable in Erlang). In AEMP, the |
|
|
726 | semantics of monitoring and linking are identical, linking is simply |
|
|
727 | two-way monitoring with automatic kill. |
|
|
728 | |
|
|
729 | =back |
|
|
730 | |
324 | =head1 SEE ALSO |
731 | =head1 SEE ALSO |
325 | |
732 | |
326 | L<AnyEvent>. |
733 | L<AnyEvent>. |
327 | |
734 | |
328 | =head1 AUTHOR |
735 | =head1 AUTHOR |