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Revision 1.45 by root, Sun Mar 4 15:12:26 2012 UTC vs.
Revision 1.46 by root, Sun Mar 4 18:48:27 2012 UTC

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13 13
14 write_log => 1251555874, "action was successful.\n" 14 write_log => 1251555874, "action was successful.\n"
15 123, ["a", "b", "c"], { foo => "bar" } 15 123, ["a", "b", "c"], { foo => "bar" }
16 16
17When using L<AnyEvent::MP> it is customary to use a descriptive string as 17When using L<AnyEvent::MP> it is customary to use a descriptive string as
18first element of a message, that indicates the type of the message. This 18first element of a message that indicates the type of the message. This
19element is called a I<tag> in L<AnyEvent::MP>, as some API functions 19element is called a I<tag> in L<AnyEvent::MP>, as some API functions
20(C<rcv>) support matching it directly. 20(C<rcv>) support matching it directly.
21 21
22Supposedly you want to send a ping message with your current time to 22Supposedly you want to send a ping message with your current time to
23somewhere, this is how such a message might look like (in Perl syntax): 23somewhere, this is how such a message might look like (in Perl syntax):
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60 60
61The strings for the I<port IDs> here are just for illustrative 61The strings for the I<port IDs> here are just for illustrative
62purposes: Even though I<ports> in L<AnyEvent::MP> are also identified by 62purposes: Even though I<ports> in L<AnyEvent::MP> are also identified by
63strings, they can't be chosen manually and are assigned by the system 63strings, they can't be chosen manually and are assigned by the system
64dynamically. These I<port IDs> are unique within a network and can also be 64dynamically. These I<port IDs> are unique within a network and can also be
65used to identify senders or as message tags for instance. 65used to identify senders, or even as message tags for instance.
66 66
67The next sections will explain the API of L<AnyEvent::MP> by going through 67The next sections will explain the API of L<AnyEvent::MP> by going through
68a few simple examples. Later some more complex idioms are introduced, 68a few simple examples. Later some more complex idioms are introduced,
69which are hopefully useful to solve some real world problems. 69which are hopefully useful to solve some real world problems.
70 70
71=head2 Passing Your First Message 71=head2 Passing Your First Message
72 72
73As a start lets have a look at the messaging API. The following example 73For starters, let's have a look at the messaging API. The following
74is just a demo to show the basic elements of message passing with 74example is just a demo to show the basic elements of message passing with
75L<AnyEvent::MP>. 75L<AnyEvent::MP>.
76 76
77The example should print: C<Ending with: 123>, in a rather complicated 77The example should print: C<Ending with: 123>, in a rather complicated
78way, by passing some message to a port. 78way, by passing some message to a port.
79 79
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92 snd $port, test => 123; 92 snd $port, test => 123;
93 93
94 print "Ending with: " . $end_cv->recv . "\n"; 94 print "Ending with: " . $end_cv->recv . "\n";
95 95
96It already uses most of the essential functions inside 96It already uses most of the essential functions inside
97L<AnyEvent::MP>: First there is the C<port> function which will create a 97L<AnyEvent::MP>: First there is the C<port> function which creates a
98I<port> and will return it's I<port ID>, a simple string. 98I<port> and will return it's I<port ID>, a simple string.
99 99
100This I<port ID> can be used to send messages to the port and install 100This I<port ID> can be used to send messages to the port and install
101handlers to receive messages on the port. Since it is a simple string 101handlers to receive messages on the port. Since it is a simple string
102it can be safely passed to other I<nodes> in the network when you want 102it can be safely passed to other I<nodes> in the network when you want
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179that you can set. The first, C<PERL_ANYEVENT_MP_WARNLEVEL> sets the 179that you can set. The first, C<PERL_ANYEVENT_MP_WARNLEVEL> sets the
180logging level. The default is C<5>, which means nothing much is 180logging level. The default is C<5>, which means nothing much is
181printed. You can increase it to C<8> or C<9> to get more verbose 181printed. You can increase it to C<8> or C<9> to get more verbose
182output. This is example output when starting a node: 182output. This is example output when starting a node:
183 183
184 2009-08-31 19:51:50 <8> node anon/5RloFvvYL8jfSScXNL8EpX starting up. 184 2012-03-04 19:41:10 <8> node cerebro starting up.
185 2009-08-31 19:51:50 <7> starting global service. 185 2012-03-04 19:41:10 <8> node listens on [10.0.0.1:4040].
186 2012-03-04 19:41:10 <9> trying connect to seed node 10.0.0.19:4040.
186 2009-08-31 19:51:50 <9> 10.0.0.17:4040 connected as ruth 187 2012-03-04 19:41:10 <9> 10.0.0.19:4040 connected as rain
187 2009-08-31 19:51:50 <7> ruth is up () 188 2012-03-04 19:41:10 <7> rain is up ()
188 2009-08-31 19:51:50 <9> ruth told us it knows about {"doom":["10.0.0.5:45143"],"rain":["10.0.0.19:4040"],"anon/4SYrtJ3ft5l1C16w2hto3t":["10.0.0.1:45920","[2002:58c6:438b:20:21d:60ff:fee8:6e36]:35788","[fd00::a00:1]:37104"],"frank":["10.0.0.18:4040"]}.
189 2009-08-31 19:51:50 <9> connecting to doom with [10.0.0.5:45143]
190 2009-08-31 19:51:50 <9> connecting to anon/4SYrtJ3ft5l1C16w2hto3t with [10.0.0.1:45920 [2002:58c6:438b:20:21d:60ff:fee8:6e36]:35788 [fd00::a00:1]:37104]
191 2009-08-31 19:51:50 <9> ruth told us its addresses (10.0.0.17:4040).
192 189
193A lot of info, but at least you can see that it does something. 190A lot of info, but at least you can see that it does something.
194 191
195The other environment variable that can be useful is 192The other environment variable that can be useful is
196C<PERL_ANYEVENT_MP_TRACE>, which, when set to a true value, will cause 193C<PERL_ANYEVENT_MP_TRACE>, which, when set to a true value, will cause
197most messages that are sent or received to be printed. In the above 194most messages that are sent or received to be printed. For example, F<aemp
198example you would see something like: 195restart rijk> might output these message exchanges:
199 196
200 SND ruth <- ["addr",["10.0.0.1:49358","[2002:58c6:438b:20:21d:60ff:fee8:6e36]:58884","[fd00::a00:1]:45006"]] 197 SND rijk <- [null,"eval","AnyEvent::Watchdog::Util::restart; ()","aemp/cerebro/z4kUPp2JT4#b"]
201 RCV ruth -> ["","AnyEvent::MP::_spawn","20QA7cWubCLTWUhFgBKOx2.x","AnyEvent::MP::Global::connect",0,"ruth"] 198 SND rain <- [null,"g_slave",{"'l":{"aemp/cerebro/z4kUPp2JT4":["10.0.0.1:48168"]}}]
202 RCV ruth -> ["","mon1","20QA7cWubCLTWUhFgBKOx2.x"] 199 SND rain <- [null,"g_find","rijk"]
203 RCV ruth -> ["20QA7cWubCLTWUhFgBKOx2.x","addr",["10.0.0.17:4040"]] 200 RCV rain -> ["","g_found","rijk",["10.0.0.23:4040"]]
204 RCV ruth -> ["20QA7cWubCLTWUhFgBKOx2.x","nodes",{"doom":["10.0.0.5:45143"],"rain":["10.0.0.19:4040"],"anon/4SYrtJ3ft5l1C16w2hto3t":["10.0.0.1:45920","[2002:58c6:438b:20:21d:60ff:fee8:6e36]:35788","[fd00::a00:1]:37104"],"frank":["10.0.0.18:4040"]}] 201 RCV rijk -> ["b",""]
205 202
206=head1 PART 1: Passing Messages Between Processes 203=head1 PART 1: Passing Messages Between Processes
207 204
208=head2 The Receiver 205=head2 The Receiver
209 206

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