… | |
… | |
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 | |
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13 | $SELF # receiving/own port id in rcv callbacks |
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14 | |
|
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15 | # ports are message endpoints |
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16 | |
|
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17 | # sending messages |
12 | snd $port, type => data...; |
18 | snd $port, type => data...; |
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19 | snd $port, @msg; |
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20 | snd @msg_with_first_element_being_a_port; |
13 | |
21 | |
|
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22 | # miniports |
|
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23 | my $miniport = port { my @msg = @_; 0 }; |
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24 | |
|
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25 | # full ports |
|
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26 | my $port = port; |
14 | rcv $port, smartmatch => $cb->($port, @msg); |
27 | rcv $port, smartmatch => $cb->(@msg); |
15 | |
|
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16 | # examples: |
|
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17 | rcv $port2, ping => sub { snd $_[0], "pong"; 0 }; |
28 | rcv $port, ping => sub { snd $_[0], "pong"; 0 }; |
18 | rcv $port1, pong => sub { warn "pong received\n" }; |
29 | rcv $port, pong => sub { warn "pong received\n"; 0 }; |
19 | snd $port2, ping => $port1; |
30 | |
|
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31 | # remote ports |
|
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32 | my $port = spawn $node, $initfunc, @initdata; |
20 | |
33 | |
21 | # more, smarter, matches (_any_ is exported by this module) |
34 | # more, smarter, matches (_any_ is exported by this module) |
22 | rcv $port, [child_died => $pid] => sub { ... |
35 | rcv $port, [child_died => $pid] => sub { ... |
23 | rcv $port, [_any_, _any_, 3] => sub { .. $_[2] is 3 |
36 | rcv $port, [_any_, _any_, 3] => sub { .. $_[2] is 3 |
24 | |
37 | |
|
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38 | # monitoring |
|
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39 | mon $port, $cb->(@msg) # callback is invoked on death |
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40 | mon $port, $otherport # kill otherport on abnormal death |
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41 | mon $port, $otherport, @msg # send message on death |
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42 | |
25 | =head1 DESCRIPTION |
43 | =head1 DESCRIPTION |
26 | |
44 | |
27 | This module (-family) implements a simple message passing framework. |
45 | This module (-family) implements a simple message passing framework. |
28 | |
46 | |
29 | Despite its simplicity, you can securely message other processes running |
47 | Despite its simplicity, you can securely message other processes running |
30 | on the same or other hosts. |
48 | on the same or other hosts. |
31 | |
49 | |
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50 | For an introduction to this module family, see the L<AnyEvent::MP::Intro> |
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51 | manual page. |
|
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52 | |
32 | At the moment, this module family is severly brokena nd underdocumented, |
53 | 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 - |
54 | so do not use. This was uploaded mainly to reserve the CPAN namespace - |
34 | stay tuned! |
55 | stay tuned! The basic API should be finished, however. |
35 | |
56 | |
36 | =head1 CONCEPTS |
57 | =head1 CONCEPTS |
37 | |
58 | |
38 | =over 4 |
59 | =over 4 |
39 | |
60 | |
40 | =item port |
61 | =item port |
41 | |
62 | |
42 | A port is something you can send messages to with the C<snd> function, and |
63 | 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 |
64 | |
44 | messages they match, messages will not be queued. |
65 | Some ports allow you to register C<rcv> handlers that can match specific |
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66 | messages. All C<rcv> handlers will receive messages they match, messages |
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67 | will not be queued. |
45 | |
68 | |
46 | =item port id - C<noderef#portname> |
69 | =item port id - C<noderef#portname> |
47 | |
70 | |
48 | A port id is always the noderef, a hash-mark (C<#>) as separator, followed |
71 | 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). |
72 | separator, and a port name (a printable string of unspecified format). An |
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73 | exception is the the node port, whose ID is identical to its node |
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74 | reference. |
50 | |
75 | |
51 | =item node |
76 | =item node |
52 | |
77 | |
53 | A node is a single process containing at least one port - the node |
78 | 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, |
79 | port. You can send messages to node ports to find existing ports or to |
55 | among other things. |
80 | create new ports, among other things. |
56 | |
81 | |
57 | Initially, nodes are either private (single-process only) or hidden |
82 | Nodes are either private (single-process only), slaves (connected to a |
58 | (connected to a master node only). Only when they epxlicitly "become |
83 | 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 | |
84 | |
61 | =item noderef - C<host:port,host:port...>, C<id@noderef>, C<id> |
85 | =item noderef - C<host:port,host:port...>, C<id@noderef>, C<id> |
62 | |
86 | |
63 | A noderef is a string that either uniquely identifies a given node (for |
87 | 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 |
88 | private and slave nodes), or contains a recipe on how to reach a given |
65 | node (for public nodes). |
89 | node (for public nodes). |
66 | |
90 | |
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91 | This recipe is simply a comma-separated list of C<address:port> pairs (for |
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92 | TCP/IP, other protocols might look different). |
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93 | |
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94 | Node references come in two flavours: resolved (containing only numerical |
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95 | addresses) or unresolved (where hostnames are used instead of addresses). |
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96 | |
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97 | Before using an unresolved node reference in a message you first have to |
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98 | resolve it. |
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99 | |
67 | =back |
100 | =back |
68 | |
101 | |
69 | =head1 VARIABLES/FUNCTIONS |
102 | =head1 VARIABLES/FUNCTIONS |
70 | |
103 | |
71 | =over 4 |
104 | =over 4 |
… | |
… | |
82 | |
115 | |
83 | use AE (); |
116 | use AE (); |
84 | |
117 | |
85 | use base "Exporter"; |
118 | use base "Exporter"; |
86 | |
119 | |
87 | our $VERSION = '0.02'; |
120 | our $VERSION = '0.1'; |
88 | our @EXPORT = qw( |
121 | our @EXPORT = qw( |
89 | NODE $NODE $PORT snd rcv _any_ |
122 | NODE $NODE *SELF node_of _any_ |
90 | create_port create_port_on |
123 | resolve_node initialise_node |
91 | create_miniport |
124 | snd rcv mon kil reg psub spawn |
92 | become_slave become_public |
125 | port |
93 | ); |
126 | ); |
94 | |
127 | |
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128 | our $SELF; |
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129 | |
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130 | sub _self_die() { |
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131 | my $msg = $@; |
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132 | $msg =~ s/\n+$// unless ref $msg; |
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133 | kil $SELF, die => $msg; |
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134 | } |
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135 | |
95 | =item NODE / $NODE |
136 | =item $thisnode = NODE / $NODE |
96 | |
137 | |
97 | The C<NODE ()> function and the C<$NODE> variable contain the noderef of |
138 | 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 |
139 | 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. |
140 | to C<become_public> or C<become_slave>, after which all local port |
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141 | identifiers become invalid. |
100 | |
142 | |
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143 | =item $noderef = node_of $port |
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144 | |
|
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145 | Extracts and returns the noderef from a portid or a noderef. |
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146 | |
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147 | =item initialise_node $noderef, $seednode, $seednode... |
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148 | |
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149 | =item initialise_node "slave/", $master, $master... |
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150 | |
|
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151 | Before a node can talk to other nodes on the network it has to initialise |
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152 | itself - the minimum a node needs to know is it's own name, and optionally |
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153 | it should know the noderefs of some other nodes in the network. |
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154 | |
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155 | This function initialises a node - it must be called exactly once (or |
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156 | never) before calling other AnyEvent::MP functions. |
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157 | |
|
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158 | All arguments are noderefs, which can be either resolved or unresolved. |
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159 | |
|
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160 | There are two types of networked nodes, public nodes and slave nodes: |
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161 | |
|
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162 | =over 4 |
|
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163 | |
|
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164 | =item public nodes |
|
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165 | |
|
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166 | For public nodes, C<$noderef> must either be a (possibly unresolved) |
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167 | noderef, in which case it will be resolved, or C<undef> (or missing), in |
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168 | which case the noderef will be guessed. |
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169 | |
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170 | Afterwards, the node will bind itself on all endpoints and try to connect |
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171 | to all additional C<$seednodes> that are specified. Seednodes are optional |
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172 | and can be used to quickly bootstrap the node into an existing network. |
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173 | |
|
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174 | =item slave nodes |
|
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175 | |
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176 | When the C<$noderef> is the special string C<slave/>, then the node will |
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177 | become a slave node. Slave nodes cannot be contacted from outside and will |
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178 | route most of their traffic to the master node that they attach to. |
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179 | |
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180 | At least one additional noderef is required: The node will try to connect |
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181 | to all of them and will become a slave attached to the first node it can |
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182 | successfully connect to. |
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183 | |
|
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184 | =back |
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185 | |
|
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186 | This function will block until all nodes have been resolved and, for slave |
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187 | nodes, until it has successfully established a connection to a master |
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188 | server. |
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189 | |
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190 | Example: become a public node listening on the default node. |
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191 | |
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192 | initialise_node; |
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193 | |
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194 | Example: become a public node, and try to contact some well-known master |
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195 | servers to become part of the network. |
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196 | |
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197 | initialise_node undef, "master1", "master2"; |
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198 | |
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199 | Example: become a public node listening on port C<4041>. |
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200 | |
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201 | initialise_node 4041; |
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202 | |
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203 | Example: become a public node, only visible on localhost port 4044. |
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204 | |
|
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205 | initialise_node "locahost:4044"; |
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206 | |
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207 | Example: become a slave node to any of the specified master servers. |
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208 | |
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209 | initialise_node "slave/", "master1", "192.168.13.17", "mp.example.net"; |
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210 | |
|
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211 | =item $cv = resolve_node $noderef |
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212 | |
|
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213 | Takes an unresolved node reference that may contain hostnames and |
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214 | abbreviated IDs, resolves all of them and returns a resolved node |
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215 | reference. |
|
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216 | |
|
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217 | In addition to C<address:port> pairs allowed in resolved noderefs, the |
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218 | following forms are supported: |
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219 | |
|
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220 | =over 4 |
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221 | |
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222 | =item the empty string |
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223 | |
|
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224 | An empty-string component gets resolved as if the default port (4040) was |
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225 | specified. |
|
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226 | |
|
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227 | =item naked port numbers (e.g. C<1234>) |
|
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228 | |
|
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229 | These are resolved by prepending the local nodename and a colon, to be |
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230 | further resolved. |
|
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231 | |
|
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232 | =item hostnames (e.g. C<localhost:1234>, C<localhost>) |
|
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233 | |
|
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234 | These are resolved by using AnyEvent::DNS to resolve them, optionally |
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235 | looking up SRV records for the C<aemp=4040> port, if no port was |
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236 | specified. |
|
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237 | |
|
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238 | =back |
|
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239 | |
|
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240 | =item $SELF |
|
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241 | |
|
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242 | Contains the current port id while executing C<rcv> callbacks or C<psub> |
|
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243 | blocks. |
|
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244 | |
|
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245 | =item SELF, %SELF, @SELF... |
|
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246 | |
|
|
247 | Due to some quirks in how perl exports variables, it is impossible to |
|
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248 | just export C<$SELF>, all the symbols called C<SELF> are exported by this |
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249 | module, but only C<$SELF> is currently used. |
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250 | |
101 | =item snd $portid, type => @data |
251 | =item snd $port, type => @data |
102 | |
252 | |
103 | =item snd $portid, @msg |
253 | =item snd $port, @msg |
104 | |
254 | |
105 | Send the given message to the given port ID, which can identify either |
255 | 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 |
256 | 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 :). |
257 | stringifies a sa port ID (such as a port object :). |
108 | |
258 | |
… | |
… | |
118 | JSON is used, then only strings, numbers and arrays and hashes consisting |
268 | 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 |
269 | 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 |
270 | that Storable can serialise and deserialise is allowed, and for the local |
121 | node, anything can be passed. |
271 | node, anything can be passed. |
122 | |
272 | |
123 | =item $local_port = create_port |
273 | =item $local_port = port |
124 | |
274 | |
125 | Create a new local port object. See the next section for allowed methods. |
275 | Create a new local port object that can be used either as a pattern |
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276 | matching port ("full port") or a single-callback port ("miniport"), |
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277 | depending on how C<rcv> callbacks are bound to the object. |
126 | |
278 | |
127 | =cut |
279 | =item $port = port { my @msg = @_; $finished } |
128 | |
280 | |
129 | sub create_port { |
281 | Creates a "miniport", that is, a very lightweight port without any pattern |
130 | my $id = "$AnyEvent::MP::Base::UNIQ." . ++$AnyEvent::MP::Base::ID; |
282 | matching behind it, and returns its ID. Semantically the same as creating |
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283 | a port and calling C<rcv $port, $callback> on it. |
131 | |
284 | |
132 | my $self = bless { |
285 | The block will be called for every message received on the port. When the |
133 | id => "$NODE#$id", |
286 | callback returns a true value its job is considered "done" and the port |
134 | names => [$id], |
287 | will be destroyed. Otherwise it will stay alive. |
135 | }, "AnyEvent::MP::Port"; |
|
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136 | |
288 | |
137 | $AnyEvent::MP::Base::PORT{$id} = sub { |
289 | The message will be passed as-is, no extra argument (i.e. no port id) will |
138 | unshift @_, $self; |
290 | be passed to the callback. |
139 | |
291 | |
140 | for (@{ $self->{rc0}{$_[1]} }) { |
292 | If you need the local port id in the callback, this works nicely: |
141 | $_ && &{$_->[0]} |
|
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142 | && undef $_; |
|
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143 | } |
|
|
144 | |
293 | |
145 | for (@{ $self->{rcv}{$_[1]} }) { |
294 | my $port; $port = port { |
146 | $_ && [@_[1 .. @{$_->[1]}]] ~~ $_->[1] |
295 | snd $otherport, reply => $port; |
147 | && &{$_->[0]} |
|
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148 | && undef $_; |
|
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149 | } |
|
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150 | |
|
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151 | for (@{ $self->{any} }) { |
|
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152 | $_ && [@_[0 .. $#{$_->[1]}]] ~~ $_->[1] |
|
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153 | && &{$_->[0]} |
|
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154 | && undef $_; |
|
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155 | } |
|
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156 | }; |
296 | }; |
157 | |
297 | |
158 | $self |
298 | =cut |
|
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299 | |
|
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300 | sub rcv($@); |
|
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301 | |
|
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302 | sub port(;&) { |
|
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303 | my $id = "$UNIQ." . $ID++; |
|
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304 | my $port = "$NODE#$id"; |
|
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305 | |
|
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306 | if (@_) { |
|
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307 | rcv $port, shift; |
|
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308 | } else { |
|
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309 | $PORT{$id} = sub { }; # nop |
|
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310 | } |
|
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311 | |
|
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312 | $port |
159 | } |
313 | } |
160 | |
314 | |
161 | =item $portid = create_miniport { } |
315 | =item reg $port, $name |
162 | |
316 | |
163 | Creates a "mini port", that is, a port without much #TODO |
317 | =item reg $name |
164 | |
318 | |
165 | =cut |
319 | Registers the given port (or C<$SELF><<< if missing) under the name |
|
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320 | C<$name>. If the name already exists it is replaced. |
166 | |
321 | |
167 | sub create_miniport(&) { |
322 | A port can only be registered under one well known name. |
168 | my $cb = shift; |
|
|
169 | my $id = "$AnyEvent::MP::Base::UNIQ." . ++$AnyEvent::MP::Base::ID; |
|
|
170 | |
323 | |
171 | $AnyEvent::MP::Base::PORT{$id} = sub { |
324 | A port automatically becomes unregistered when it is killed. |
172 | # unshift @_, "$NODE#$id"; |
|
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173 | &$cb |
|
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174 | and delete $AnyEvent::MP::Base::PORT{$id}; |
|
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175 | }; |
|
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176 | |
325 | |
177 | "$NODE#$id" |
326 | =cut |
|
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327 | |
|
|
328 | sub reg(@) { |
|
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329 | my $port = @_ > 1 ? shift : $SELF || Carp::croak 'reg: called with one argument only, but $SELF not set,'; |
|
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330 | |
|
|
331 | $REG{$_[0]} = $port; |
178 | } |
332 | } |
179 | |
333 | |
180 | package AnyEvent::MP::Port; |
334 | =item rcv $port, $callback->(@msg) |
181 | |
335 | |
182 | =back |
336 | Replaces the callback on the specified miniport (after converting it to |
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337 | one if required). |
183 | |
338 | |
184 | =head1 METHODS FOR PORT OBJECTS |
339 | =item rcv $port, tagstring => $callback->(@msg), ... |
185 | |
340 | |
186 | =over 4 |
341 | =item rcv $port, $smartmatch => $callback->(@msg), ... |
187 | |
342 | |
188 | =item "$port" |
|
|
189 | |
|
|
190 | A port object stringifies to its port ID, so can be used directly for |
|
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191 | C<snd> operations. |
|
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192 | |
|
|
193 | =cut |
|
|
194 | |
|
|
195 | use overload |
|
|
196 | '""' => sub { $_[0]{id} }, |
|
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197 | fallback => 1; |
|
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198 | |
|
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199 | =item $port->rcv (type => $callback->($port, @msg)) |
|
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200 | |
|
|
201 | =item $port->rcv ($smartmatch => $callback->($port, @msg)) |
|
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202 | |
|
|
203 | =item $port->rcv ([$smartmatch...] => $callback->($port, @msg)) |
343 | =item rcv $port, [$smartmatch...] => $callback->(@msg), ... |
204 | |
344 | |
205 | Register a callback on the given port. |
345 | Register callbacks to be called on matching messages on the given full |
|
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346 | port (after converting it to one if required) and return the port. |
206 | |
347 | |
207 | The callback has to return a true value when its work is done, after |
348 | The callback has to return a true value when its work is done, after |
208 | which is will be removed, or a false value in which case it will stay |
349 | which is will be removed, or a false value in which case it will stay |
209 | registered. |
350 | registered. |
210 | |
351 | |
|
|
352 | The global C<$SELF> (exported by this module) contains C<$port> while |
|
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353 | executing the callback. |
|
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354 | |
|
|
355 | Runtime errors during callback execution will result in the port being |
|
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356 | C<kil>ed. |
|
|
357 | |
211 | If the match is an array reference, then it will be matched against the |
358 | If the match is an array reference, then it will be matched against the |
212 | first elements of the message, otherwise only the first element is being |
359 | first elements of the message, otherwise only the first element is being |
213 | matched. |
360 | matched. |
214 | |
361 | |
215 | Any element in the match that is specified as C<_any_> (a function |
362 | Any element in the match that is specified as C<_any_> (a function |
… | |
… | |
217 | |
364 | |
218 | While not required, it is highly recommended that the first matching |
365 | While not required, it is highly recommended that the first matching |
219 | element is a string identifying the message. The one-string-only match is |
366 | element is a string identifying the message. The one-string-only match is |
220 | also the most efficient match (by far). |
367 | also the most efficient match (by far). |
221 | |
368 | |
|
|
369 | Example: create a port and bind receivers on it in one go. |
|
|
370 | |
|
|
371 | my $port = rcv port, |
|
|
372 | msg1 => sub { ...; 0 }, |
|
|
373 | msg2 => sub { ...; 0 }, |
|
|
374 | ; |
|
|
375 | |
|
|
376 | Example: create a port, bind receivers and send it in a message elsewhere |
|
|
377 | in one go: |
|
|
378 | |
|
|
379 | snd $otherport, reply => |
|
|
380 | rcv port, |
|
|
381 | msg1 => sub { ...; 0 }, |
|
|
382 | ... |
|
|
383 | ; |
|
|
384 | |
222 | =cut |
385 | =cut |
223 | |
386 | |
224 | sub rcv($@) { |
387 | sub rcv($@) { |
225 | my ($self, $match, $cb) = @_; |
388 | my $port = shift; |
|
|
389 | my ($noderef, $portid) = split /#/, $port, 2; |
226 | |
390 | |
227 | if (!ref $match) { |
391 | ($NODE{$noderef} || add_node $noderef) == $NODE{""} |
228 | push @{ $self->{rc0}{$match} }, [$cb]; |
392 | or Carp::croak "$port: rcv can only be called on local ports, caught"; |
229 | } elsif (("ARRAY" eq ref $match && !ref $match->[0])) { |
393 | |
230 | my ($type, @match) = @$match; |
394 | if (@_ == 1) { |
231 | @match |
395 | my $cb = shift; |
232 | ? push @{ $self->{rcv}{$match->[0]} }, [$cb, \@match] |
396 | delete $PORT_DATA{$portid}; |
233 | : push @{ $self->{rc0}{$match->[0]} }, [$cb]; |
397 | $PORT{$portid} = sub { |
|
|
398 | local $SELF = $port; |
|
|
399 | eval { |
|
|
400 | &$cb |
|
|
401 | and kil $port; |
|
|
402 | }; |
|
|
403 | _self_die if $@; |
|
|
404 | }; |
234 | } else { |
405 | } else { |
|
|
406 | my $self = $PORT_DATA{$portid} ||= do { |
|
|
407 | my $self = bless { |
|
|
408 | id => $port, |
|
|
409 | }, "AnyEvent::MP::Port"; |
|
|
410 | |
|
|
411 | $PORT{$portid} = sub { |
|
|
412 | local $SELF = $port; |
|
|
413 | |
|
|
414 | eval { |
|
|
415 | for (@{ $self->{rc0}{$_[0]} }) { |
|
|
416 | $_ && &{$_->[0]} |
|
|
417 | && undef $_; |
|
|
418 | } |
|
|
419 | |
|
|
420 | for (@{ $self->{rcv}{$_[0]} }) { |
|
|
421 | $_ && [@_[1 .. @{$_->[1]}]] ~~ $_->[1] |
|
|
422 | && &{$_->[0]} |
|
|
423 | && undef $_; |
|
|
424 | } |
|
|
425 | |
|
|
426 | for (@{ $self->{any} }) { |
|
|
427 | $_ && [@_[0 .. $#{$_->[1]}]] ~~ $_->[1] |
|
|
428 | && &{$_->[0]} |
|
|
429 | && undef $_; |
|
|
430 | } |
|
|
431 | }; |
|
|
432 | _self_die if $@; |
|
|
433 | }; |
|
|
434 | |
|
|
435 | $self |
|
|
436 | }; |
|
|
437 | |
|
|
438 | "AnyEvent::MP::Port" eq ref $self |
|
|
439 | or Carp::croak "$port: rcv can only be called on message matching ports, caught"; |
|
|
440 | |
|
|
441 | while (@_) { |
|
|
442 | my ($match, $cb) = splice @_, 0, 2; |
|
|
443 | |
|
|
444 | if (!ref $match) { |
|
|
445 | push @{ $self->{rc0}{$match} }, [$cb]; |
|
|
446 | } elsif (("ARRAY" eq ref $match && !ref $match->[0])) { |
|
|
447 | my ($type, @match) = @$match; |
|
|
448 | @match |
|
|
449 | ? push @{ $self->{rcv}{$match->[0]} }, [$cb, \@match] |
|
|
450 | : push @{ $self->{rc0}{$match->[0]} }, [$cb]; |
|
|
451 | } else { |
235 | push @{ $self->{any} }, [$cb, $match]; |
452 | push @{ $self->{any} }, [$cb, $match]; |
|
|
453 | } |
|
|
454 | } |
|
|
455 | } |
|
|
456 | |
|
|
457 | $port |
|
|
458 | } |
|
|
459 | |
|
|
460 | =item $closure = psub { BLOCK } |
|
|
461 | |
|
|
462 | Remembers C<$SELF> and creates a closure out of the BLOCK. When the |
|
|
463 | closure is executed, sets up the environment in the same way as in C<rcv> |
|
|
464 | callbacks, i.e. runtime errors will cause the port to get C<kil>ed. |
|
|
465 | |
|
|
466 | This is useful when you register callbacks from C<rcv> callbacks: |
|
|
467 | |
|
|
468 | rcv delayed_reply => sub { |
|
|
469 | my ($delay, @reply) = @_; |
|
|
470 | my $timer = AE::timer $delay, 0, psub { |
|
|
471 | snd @reply, $SELF; |
|
|
472 | }; |
|
|
473 | }; |
|
|
474 | |
|
|
475 | =cut |
|
|
476 | |
|
|
477 | sub psub(&) { |
|
|
478 | my $cb = shift; |
|
|
479 | |
|
|
480 | my $port = $SELF |
|
|
481 | or Carp::croak "psub can only be called from within rcv or psub callbacks, not"; |
|
|
482 | |
|
|
483 | sub { |
|
|
484 | local $SELF = $port; |
|
|
485 | |
|
|
486 | if (wantarray) { |
|
|
487 | my @res = eval { &$cb }; |
|
|
488 | _self_die if $@; |
|
|
489 | @res |
|
|
490 | } else { |
|
|
491 | my $res = eval { &$cb }; |
|
|
492 | _self_die if $@; |
|
|
493 | $res |
|
|
494 | } |
236 | } |
495 | } |
237 | } |
496 | } |
238 | |
497 | |
239 | =item $port->register ($name) |
498 | =item $guard = mon $port, $cb->(@reason) |
240 | |
499 | |
241 | Registers the given port under the well known name C<$name>. If the name |
500 | =item $guard = mon $port, $rcvport |
242 | already exists it is replaced. |
|
|
243 | |
501 | |
244 | A port can only be registered under one well known name. |
502 | =item $guard = mon $port |
245 | |
503 | |
246 | =cut |
504 | =item $guard = mon $port, $rcvport, @msg |
247 | |
505 | |
248 | sub register { |
506 | Monitor the given port and do something when the port is killed, and |
249 | my ($self, $name) = @_; |
507 | optionally return a guard that can be used to stop monitoring again. |
250 | |
508 | |
251 | $self->{wkname} = $name; |
509 | In the first form (callback), the callback is simply called with any |
252 | $AnyEvent::MP::Base::WKP{$name} = "$self"; |
510 | number of C<@reason> elements (no @reason means that the port was deleted |
|
|
511 | "normally"). Note also that I<< the callback B<must> never die >>, so use |
|
|
512 | C<eval> if unsure. |
|
|
513 | |
|
|
514 | In the second form (another port given), the other port (C<$rcvport) |
|
|
515 | will be C<kil>'ed with C<@reason>, iff a @reason was specified, i.e. on |
|
|
516 | "normal" kils nothing happens, while under all other conditions, the other |
|
|
517 | port is killed with the same reason. |
|
|
518 | |
|
|
519 | The third form (kill self) is the same as the second form, except that |
|
|
520 | C<$rvport> defaults to C<$SELF>. |
|
|
521 | |
|
|
522 | In the last form (message), a message of the form C<@msg, @reason> will be |
|
|
523 | C<snd>. |
|
|
524 | |
|
|
525 | As a rule of thumb, monitoring requests should always monitor a port from |
|
|
526 | a local port (or callback). The reason is that kill messages might get |
|
|
527 | lost, just like any other message. Another less obvious reason is that |
|
|
528 | even monitoring requests can get lost (for exmaple, when the connection |
|
|
529 | to the other node goes down permanently). When monitoring a port locally |
|
|
530 | these problems do not exist. |
|
|
531 | |
|
|
532 | Example: call a given callback when C<$port> is killed. |
|
|
533 | |
|
|
534 | mon $port, sub { warn "port died because of <@_>\n" }; |
|
|
535 | |
|
|
536 | Example: kill ourselves when C<$port> is killed abnormally. |
|
|
537 | |
|
|
538 | mon $port; |
|
|
539 | |
|
|
540 | Example: send us a restart message when another C<$port> is killed. |
|
|
541 | |
|
|
542 | mon $port, $self => "restart"; |
|
|
543 | |
|
|
544 | =cut |
|
|
545 | |
|
|
546 | sub mon { |
|
|
547 | my ($noderef, $port) = split /#/, shift, 2; |
|
|
548 | |
|
|
549 | my $node = $NODE{$noderef} || add_node $noderef; |
|
|
550 | |
|
|
551 | my $cb = @_ ? $_[0] : $SELF || Carp::croak 'mon: called with one argument only, but $SELF not set,'; |
|
|
552 | |
|
|
553 | unless (ref $cb) { |
|
|
554 | if (@_) { |
|
|
555 | # send a kill info message |
|
|
556 | my (@msg) = @_; |
|
|
557 | $cb = sub { snd @msg, @_ }; |
|
|
558 | } else { |
|
|
559 | # simply kill other port |
|
|
560 | my $port = $cb; |
|
|
561 | $cb = sub { kil $port, @_ if @_ }; |
|
|
562 | } |
|
|
563 | } |
|
|
564 | |
|
|
565 | $node->monitor ($port, $cb); |
|
|
566 | |
|
|
567 | defined wantarray |
|
|
568 | and AnyEvent::Util::guard { $node->unmonitor ($port, $cb) } |
253 | } |
569 | } |
254 | |
570 | |
255 | =item $port->destroy |
571 | =item $guard = mon_guard $port, $ref, $ref... |
256 | |
572 | |
257 | Explicitly destroy/remove/nuke/vaporise the port. |
573 | Monitors the given C<$port> and keeps the passed references. When the port |
|
|
574 | is killed, the references will be freed. |
258 | |
575 | |
259 | Ports are normally kept alive by there mere existance alone, and need to |
576 | Optionally returns a guard that will stop the monitoring. |
260 | be destroyed explicitly. |
|
|
261 | |
577 | |
262 | =cut |
578 | This function is useful when you create e.g. timers or other watchers and |
|
|
579 | want to free them when the port gets killed: |
263 | |
580 | |
264 | sub destroy { |
581 | $port->rcv (start => sub { |
265 | my ($self) = @_; |
582 | my $timer; $timer = mon_guard $port, AE::timer 1, 1, sub { |
|
|
583 | undef $timer if 0.9 < rand; |
|
|
584 | }); |
|
|
585 | }); |
266 | |
586 | |
267 | delete $AnyEvent::MP::Base::WKP{ $self->{wkname} }; |
587 | =cut |
268 | |
588 | |
269 | delete $AnyEvent::MP::Base::PORT{$_} |
589 | sub mon_guard { |
270 | for @{ $self->{names} }; |
590 | my ($port, @refs) = @_; |
|
|
591 | |
|
|
592 | #TODO: mon-less form? |
|
|
593 | |
|
|
594 | mon $port, sub { 0 && @refs } |
271 | } |
595 | } |
272 | |
596 | |
273 | =back |
597 | =item kil $port[, @reason] |
274 | |
598 | |
275 | =head1 FUNCTIONS FOR NODES |
599 | Kill the specified port with the given C<@reason>. |
276 | |
600 | |
277 | =over 4 |
601 | If no C<@reason> is specified, then the port is killed "normally" (linked |
|
|
602 | ports will not be kileld, or even notified). |
278 | |
603 | |
279 | =item mon $noderef, $callback->($noderef, $status, $) |
604 | Otherwise, linked ports get killed with the same reason (second form of |
|
|
605 | C<mon>, see below). |
280 | |
606 | |
281 | Monitors the given noderef. |
607 | Runtime errors while evaluating C<rcv> callbacks or inside C<psub> blocks |
|
|
608 | will be reported as reason C<< die => $@ >>. |
282 | |
609 | |
283 | =item become_public endpoint... |
610 | Transport/communication errors are reported as C<< transport_error => |
|
|
611 | $message >>. |
284 | |
612 | |
285 | Tells the node to become a public node, i.e. reachable from other nodes. |
|
|
286 | |
|
|
287 | If no arguments are given, or the first argument is C<undef>, then |
|
|
288 | AnyEvent::MP tries to bind on port C<4040> on all IP addresses that the |
|
|
289 | local nodename resolves to. |
|
|
290 | |
|
|
291 | Otherwise the first argument must be an array-reference with transport |
|
|
292 | endpoints ("ip:port", "hostname:port") or port numbers (in which case the |
|
|
293 | local nodename is used as hostname). The endpoints are all resolved and |
|
|
294 | will become the node reference. |
|
|
295 | |
|
|
296 | =cut |
613 | =cut |
|
|
614 | |
|
|
615 | =item $port = spawn $node, $initfunc[, @initdata] |
|
|
616 | |
|
|
617 | Creates a port on the node C<$node> (which can also be a port ID, in which |
|
|
618 | case it's the node where that port resides). |
|
|
619 | |
|
|
620 | The port ID of the newly created port is return immediately, and it is |
|
|
621 | permissible to immediately start sending messages or monitor the port. |
|
|
622 | |
|
|
623 | After the port has been created, the init function is |
|
|
624 | called. This function must be a fully-qualified function name |
|
|
625 | (e.g. C<MyApp::Chat::Server::init>). |
|
|
626 | |
|
|
627 | If the function doesn't exist, then the node tries to C<require> |
|
|
628 | the package, then the package above the package and so on (e.g. |
|
|
629 | C<MyApp::Chat::Server>, C<MyApp::Chat>, C<MyApp>) until the function |
|
|
630 | exists or it runs out of package names. |
|
|
631 | |
|
|
632 | The init function is then called with the newly-created port as context |
|
|
633 | object (C<$SELF>) and the C<@initdata> values as arguments. |
|
|
634 | |
|
|
635 | A common idiom is to pass your own port, monitor the spawned port, and |
|
|
636 | in the init function, monitor the original port. This two-way monitoring |
|
|
637 | ensures that both ports get cleaned up when there is a problem. |
|
|
638 | |
|
|
639 | Example: spawn a chat server port on C<$othernode>. |
|
|
640 | |
|
|
641 | # this node, executed from within a port context: |
|
|
642 | my $server = spawn $othernode, "MyApp::Chat::Server::connect", $SELF; |
|
|
643 | mon $server; |
|
|
644 | |
|
|
645 | # init function on C<$othernode> |
|
|
646 | sub connect { |
|
|
647 | my ($srcport) = @_; |
|
|
648 | |
|
|
649 | mon $srcport; |
|
|
650 | |
|
|
651 | rcv $SELF, sub { |
|
|
652 | ... |
|
|
653 | }; |
|
|
654 | } |
|
|
655 | |
|
|
656 | =cut |
|
|
657 | |
|
|
658 | sub _spawn { |
|
|
659 | my $port = shift; |
|
|
660 | my $init = shift; |
|
|
661 | |
|
|
662 | local $SELF = "$NODE#$port"; |
|
|
663 | eval { |
|
|
664 | &{ load_func $init } |
|
|
665 | }; |
|
|
666 | _self_die if $@; |
|
|
667 | } |
|
|
668 | |
|
|
669 | sub spawn(@) { |
|
|
670 | my ($noderef, undef) = split /#/, shift, 2; |
|
|
671 | |
|
|
672 | my $id = "$RUNIQ." . $ID++; |
|
|
673 | |
|
|
674 | $_[0] =~ /::/ |
|
|
675 | or Carp::croak "spawn init function must be a fully-qualified name, caught"; |
|
|
676 | |
|
|
677 | ($NODE{$noderef} || add_node $noderef) |
|
|
678 | ->send (["", "AnyEvent::MP::_spawn" => $id, @_]); |
|
|
679 | |
|
|
680 | "$noderef#$id" |
|
|
681 | } |
297 | |
682 | |
298 | =back |
683 | =back |
299 | |
684 | |
300 | =head1 NODE MESSAGES |
685 | =head1 NODE MESSAGES |
301 | |
686 | |
302 | Nodes understand the following messages sent to them. Many of them take |
687 | Nodes understand the following messages sent to them. Many of them take |
303 | arguments called C<@reply>, which will simply be used to compose a reply |
688 | arguments called C<@reply>, which will simply be used to compose a reply |
304 | message - C<$reply[0]> is the port to reply to, C<$reply[1]> the type and |
689 | message - C<$reply[0]> is the port to reply to, C<$reply[1]> the type and |
305 | the remaining arguments are simply the message data. |
690 | the remaining arguments are simply the message data. |
306 | |
691 | |
|
|
692 | While other messages exist, they are not public and subject to change. |
|
|
693 | |
307 | =over 4 |
694 | =over 4 |
308 | |
695 | |
309 | =cut |
696 | =cut |
310 | |
697 | |
311 | =item wkp => $name, @reply |
698 | =item lookup => $name, @reply |
312 | |
699 | |
313 | Replies with the port ID of the specified well-known port, or C<undef>. |
700 | Replies with the port ID of the specified well-known port, or C<undef>. |
314 | |
701 | |
315 | =item devnull => ... |
702 | =item devnull => ... |
316 | |
703 | |
… | |
… | |
339 | snd $NODE, time => $myport, timereply => 1, 2; |
726 | snd $NODE, time => $myport, timereply => 1, 2; |
340 | # => snd $myport, timereply => 1, 2, <time> |
727 | # => snd $myport, timereply => 1, 2, <time> |
341 | |
728 | |
342 | =back |
729 | =back |
343 | |
730 | |
|
|
731 | =head1 AnyEvent::MP vs. Distributed Erlang |
|
|
732 | |
|
|
733 | AnyEvent::MP got lots of its ideas from distributed Erlang (Erlang node |
|
|
734 | == aemp node, Erlang process == aemp port), so many of the documents and |
|
|
735 | programming techniques employed by Erlang apply to AnyEvent::MP. Here is a |
|
|
736 | sample: |
|
|
737 | |
|
|
738 | http://www.Erlang.se/doc/programming_rules.shtml |
|
|
739 | http://Erlang.org/doc/getting_started/part_frame.html # chapters 3 and 4 |
|
|
740 | http://Erlang.org/download/Erlang-book-part1.pdf # chapters 5 and 6 |
|
|
741 | http://Erlang.org/download/armstrong_thesis_2003.pdf # chapters 4 and 5 |
|
|
742 | |
|
|
743 | Despite the similarities, there are also some important differences: |
|
|
744 | |
|
|
745 | =over 4 |
|
|
746 | |
|
|
747 | =item * Node references contain the recipe on how to contact them. |
|
|
748 | |
|
|
749 | Erlang relies on special naming and DNS to work everywhere in the |
|
|
750 | same way. AEMP relies on each node knowing it's own address(es), with |
|
|
751 | convenience functionality. |
|
|
752 | |
|
|
753 | This means that AEMP requires a less tightly controlled environment at the |
|
|
754 | cost of longer node references and a slightly higher management overhead. |
|
|
755 | |
|
|
756 | =item * Erlang uses processes and a mailbox, AEMP does not queue. |
|
|
757 | |
|
|
758 | Erlang uses processes that selctively receive messages, and therefore |
|
|
759 | needs a queue. AEMP is event based, queuing messages would serve no useful |
|
|
760 | purpose. |
|
|
761 | |
|
|
762 | (But see L<Coro::MP> for a more Erlang-like process model on top of AEMP). |
|
|
763 | |
|
|
764 | =item * Erlang sends are synchronous, AEMP sends are asynchronous. |
|
|
765 | |
|
|
766 | Sending messages in Erlang is synchronous and blocks the process. AEMP |
|
|
767 | sends are immediate, connection establishment is handled in the |
|
|
768 | background. |
|
|
769 | |
|
|
770 | =item * Erlang can silently lose messages, AEMP cannot. |
|
|
771 | |
|
|
772 | Erlang makes few guarantees on messages delivery - messages can get lost |
|
|
773 | without any of the processes realising it (i.e. you send messages a, b, |
|
|
774 | and c, and the other side only receives messages a and c). |
|
|
775 | |
|
|
776 | AEMP guarantees correct ordering, and the guarantee that there are no |
|
|
777 | holes in the message sequence. |
|
|
778 | |
|
|
779 | =item * In Erlang, processes can be declared dead and later be found to be |
|
|
780 | alive. |
|
|
781 | |
|
|
782 | In Erlang it can happen that a monitored process is declared dead and |
|
|
783 | linked processes get killed, but later it turns out that the process is |
|
|
784 | still alive - and can receive messages. |
|
|
785 | |
|
|
786 | In AEMP, when port monitoring detects a port as dead, then that port will |
|
|
787 | eventually be killed - it cannot happen that a node detects a port as dead |
|
|
788 | and then later sends messages to it, finding it is still alive. |
|
|
789 | |
|
|
790 | =item * Erlang can send messages to the wrong port, AEMP does not. |
|
|
791 | |
|
|
792 | In Erlang it is quite possible that a node that restarts reuses a process |
|
|
793 | ID known to other nodes for a completely different process, causing |
|
|
794 | messages destined for that process to end up in an unrelated process. |
|
|
795 | |
|
|
796 | AEMP never reuses port IDs, so old messages or old port IDs floating |
|
|
797 | around in the network will not be sent to an unrelated port. |
|
|
798 | |
|
|
799 | =item * Erlang uses unprotected connections, AEMP uses secure |
|
|
800 | authentication and can use TLS. |
|
|
801 | |
|
|
802 | AEMP can use a proven protocol - SSL/TLS - to protect connections and |
|
|
803 | securely authenticate nodes. |
|
|
804 | |
|
|
805 | =item * The AEMP protocol is optimised for both text-based and binary |
|
|
806 | communications. |
|
|
807 | |
|
|
808 | The AEMP protocol, unlike the Erlang protocol, supports both |
|
|
809 | language-independent text-only protocols (good for debugging) and binary, |
|
|
810 | language-specific serialisers (e.g. Storable). |
|
|
811 | |
|
|
812 | It has also been carefully designed to be implementable in other languages |
|
|
813 | with a minimum of work while gracefully degrading fucntionality to make the |
|
|
814 | protocol simple. |
|
|
815 | |
|
|
816 | =item * AEMP has more flexible monitoring options than Erlang. |
|
|
817 | |
|
|
818 | In Erlang, you can chose to receive I<all> exit signals as messages |
|
|
819 | or I<none>, there is no in-between, so monitoring single processes is |
|
|
820 | difficult to implement. Monitoring in AEMP is more flexible than in |
|
|
821 | Erlang, as one can choose between automatic kill, exit message or callback |
|
|
822 | on a per-process basis. |
|
|
823 | |
|
|
824 | =item * Erlang tries to hide remote/local connections, AEMP does not. |
|
|
825 | |
|
|
826 | Monitoring in Erlang is not an indicator of process death/crashes, |
|
|
827 | as linking is (except linking is unreliable in Erlang). |
|
|
828 | |
|
|
829 | In AEMP, you don't "look up" registered port names or send to named ports |
|
|
830 | that might or might not be persistent. Instead, you normally spawn a port |
|
|
831 | on the remote node. The init function monitors the you, and you monitor |
|
|
832 | the remote port. Since both monitors are local to the node, they are much |
|
|
833 | more reliable. |
|
|
834 | |
|
|
835 | This also saves round-trips and avoids sending messages to the wrong port |
|
|
836 | (hard to do in Erlang). |
|
|
837 | |
|
|
838 | =back |
|
|
839 | |
344 | =head1 SEE ALSO |
840 | =head1 SEE ALSO |
345 | |
841 | |
346 | L<AnyEvent>. |
842 | L<AnyEvent>. |
347 | |
843 | |
348 | =head1 AUTHOR |
844 | =head1 AUTHOR |