1Net::Server::Multiplex(U3s)er Contributed Perl DocumentatNieotn::Server::Multiplex(3)
2
6 Net::Server::Multiplex - Multiplex several connections within one
7 process
8
10 package MyPlexer;
11 use base qw(Net::Server::Multiplex);
13 sub mux_input {
15 #...code...
16 }
17 __PACKAGE__->run();
19
21 This personality is designed to handle multiple connections all within
22 one process. It should only be used with protocols that are guaranteed
23 to be able to respond quickly on a packet by packet basis. If
24 determining a response could take a while or an unknown period of time,
25 all other connections established will block until the response
26 completes. If this condition might ever occur, this personality should
27 probably not be used.
28 This takes some nice features of Net::Server (like the server listen
30 socket setup, configuration file processing, safe signal handling,
31 convenient inet style STDIN/STDOUT handling, logging features,
32 deamonization and pid tracking, and restartability -SIGHUP) and some
33 nice features of IO::Multiplex (automatic buffered IO and per-file-
34 handle objects) and combines them for an easy-to-use interace.
35 See examples/samplechat.pl distributed with Net::Server for a simple
37 chat server that uses several of these features.
38
40 The process flow is written in an open, easy to override, easy to hook,
41 fashion. The basic flow is shown below.
42 $self->configure_hook;
44 $self->configure(@_);
46 $self->post_configure;
48 $self->post_configure_hook;
50 $self->pre_bind;
52 $self->bind;
54 if (Restarting server) {
56 $self->restart_open_hook();
57 }
58 $self->post_bind_hook;
60 $self->post_bind;
62 $self->pre_loop_hook;
64 $self->loop; # This basically just runs IO::Multiplex::loop
66 # For routines inside a $self->loop
67 # See CLIENT PROCESSING below
68 $self->pre_server_close_hook;
70 $self->post_child_cleanup_hook;
72 $self->server_close;
74 if (Restarting server) {
76 $self->restart_close_hook();
77 $self->hup_server;
78 # Redo process again starting with configure_hook
79 }
80 The server then exits.
82
84 The following represents the client processing program flow:
85 $self->{server}->{client} = Net::Server::Proto::TCP->accept(); # NOTE: Multiplexed with mux_input() below
87 if (check_for_dequeue seconds have passed) {
89 $self->run_dequeue();
90 }
91 $self->get_client_info;
93 $self->post_accept_hook; # Net::Server style
95 if ($self->allow_deny
97 && $self->allow_deny_hook) {
98 # (Net::Server style $self->process_request() is never called.)
100 # A unique client specific object is created
102 # for all mux_* methods from this point on.
103 $self = __PACKAGE__->new($self, client);
104 $self->mux_connection; # IO::Multiplex style
106 for (every packet received) {
108 $self->mux_input; # NOTE: Multiplexed with accept() above
109 }
110 } else {
112 $self->request_denied_hook;
114 # Notice that if either allow_deny or allow_deny_hook fails, then
116 # new(), mux_connection(), and mux_input() will never be called.
117 # mux_eof() and mux_close() will still be called, but using a
118 # common listen socket callback object instead of a unique client
119 # specific object.
120 }
122 $self->mux_eof;
124 $self->post_process_request_hook;
126 $self->mux_close;
128 This process then loops multiplexing between the accept() for the next
130 connection and mux_input() when input arrives to avoid blocking either
131 one.
132
134 The *_hook methods mentioned above are meant to be overridden with your
135 own subroutines if you desire to provide additional functionality.
136 The loop() method of Net::Server has been overridden to run the loop
138 routine of IO::Multiplex instead. The Net::Server methods may access
139 the IO::Multiplex object at "$self->{mux}" if desired. The
140 IO::Multiplex methods may access the Net::Server object at
141 "$self->{net_server}" if desired.
142 The process_request() method is never used with this personality.
144 The other Net::Server hooks and methods should work the same.
146 "$self->run_dequeue()"
148 This hook only gets called in conjunction with the
149 check_for_dequeue setting. It will run every check_for_dequeue
150 seconds. Since no forking is done, this hook should run fast in
151 order to prevent blocking the rest of the processing.
152
154 set_timeout
155 To utilize the optional timeout feature of IO::Multiplex, you need to
156 specify a timeout by using the set_timeout method.
157 $self->{net_server}->{mux}->set_timeout($fh, $seconds_from_now);
159 $fh may be either a client socket or a listen socket file descriptor
161 within the mux. $seconds_from_now may be fractional to achieve more
162 precise timeouts. This is used in conjunction with mux_timeout, which
163 you should define yourself.
164 mux_timeout
166 The main loop() routine will call $obj->mux_timeout($mux, $fh) when the
167 timeout specified in set_timeout is reached where $fh is the same as
168 the one specified in set_timeout() and $obj is its corresponding object
169 (either the unique client specific object or the main listen callback
170 object) and $mux is the main IO::Multiplex object itself.
171
173 Callback objects should support the following interface. You do not
174 have to provide all of these methods, just provide the ones you are
175 interested in. These are just like the IO::Multiplex hooks except that
176 STDOUT is tied to the corresponding client socket handle for your
177 convenience and to more closely emulate the Net::Server model.
178 However, unlike some other Net::Server personalities, you should never
179 read directly from STDIN yourself. You should define one or more of
180 the following methods:
181 mux_connection ($mux,$fh)
183 (OPTIONAL) Run once when the client first connects if the allow_deny
184 passes. Note that the "$self->{net_server}->{server}" property hash
185 may be modified by future connections through Net::Server. Any values
186 within it that this object may need to use later should be copied
187 within its own object at this point.
188 Example:
190 $self->{peerport} = $self->{net_server}->{server}->{peerport};
191 mux_input ($mux,$fh,\$data)
193 (REQUIRED) Run each time a packet is read. It should consume $data
194 starting at the left and leave unconsumed data in the scalar for future
195 calls to mux_input.
196 mux_eof ($mux,$fh,\$data)
198 (OPTIONAL) Run once when the client is done writing. It should consume
199 the rest of $data since mux_input() will never be run again.
200 mux_close ($mux,$fh)
202 (OPTIONAL) Run after the entire client socket has been closed. No more
203 attempts should be made to read or write to the client or to STDOUT.
204 mux_timeout ($mux,$fh)
206 (OPTIONAL) Run once when the set_timeout setting expires as explained
207 above.
208
210 This is only known to work with TCP servers.
211 If you need to use the IO::Multiplex style set_timeout / mux_timeout
213 interface, you cannot use the Net::Server style check_for_dequeue /
214 run_dequeue interface. It will not work if the check_for_dequeue
215 option is specified. The run_dequeue method is just a compatibility
216 interface to comply with the Net::Server::Fork style run_dequeue but is
217 implemented in terms of the IO::Multiplex style set_timeout and
218 mux_timeout methods.
219
221 Rob Brown <bbb@cpan.org>
222
224 Paul Seamons <paul@seamons.com>
225
227 This package may be distributed under the terms of either the
228 GNU General Public License
229 or the
230 Perl Artistic License
231 All rights reserved.
233
235 Net::Server by Paul Seamons <paul@seamons.com>,
236 IO::Multiplex by Bruce Keeler <bruce@gridpoint.com>.
238perl v5.32.1 2021-01-27 Net::Server::Multiplex(3)