| … | |
… | |
| 4 | |
4 | |
| 5 | =head1 SYNOPSIS |
5 | =head1 SYNOPSIS |
| 6 | |
6 | |
| 7 | use AnyEvent::MP; |
7 | use AnyEvent::MP; |
| 8 | |
8 | |
| 9 | $NODE # contains this node's noderef |
9 | $NODE # contains this node's node ID |
| 10 | NODE # returns this node's noderef |
10 | NODE # returns this node's node ID |
| 11 | NODE $port # returns the noderef of the port |
|
|
| 12 | |
11 | |
| 13 | $SELF # receiving/own port id in rcv callbacks |
12 | $SELF # receiving/own port id in rcv callbacks |
| 14 | |
13 | |
| 15 | # initialise the node so it can send/receive messages |
14 | # initialise the node so it can send/receive messages |
| 16 | initialise_node; |
15 | configure; |
| 17 | |
16 | |
| 18 | # ports are message endpoints |
17 | # ports are message destinations |
| 19 | |
18 | |
| 20 | # sending messages |
19 | # sending messages |
| 21 | snd $port, type => data...; |
20 | snd $port, type => data...; |
| 22 | snd $port, @msg; |
21 | snd $port, @msg; |
| 23 | snd @msg_with_first_element_being_a_port; |
22 | snd @msg_with_first_element_being_a_port; |
| 24 | |
23 | |
| 25 | # creating/using ports, the simple way |
24 | # creating/using ports, the simple way |
| 26 | my $simple_port = port { my @msg = @_; 0 }; |
25 | my $simple_port = port { my @msg = @_ }; |
| 27 | |
26 | |
| 28 | # creating/using ports, tagged message matching |
27 | # creating/using ports, tagged message matching |
| 29 | my $port = port; |
28 | my $port = port; |
| 30 | rcv $port, ping => sub { snd $_[0], "pong"; 0 }; |
29 | rcv $port, ping => sub { snd $_[0], "pong" }; |
| 31 | rcv $port, pong => sub { warn "pong received\n"; 0 }; |
30 | rcv $port, pong => sub { warn "pong received\n" }; |
| 32 | |
31 | |
| 33 | # create a port on another node |
32 | # create a port on another node |
| 34 | my $port = spawn $node, $initfunc, @initdata; |
33 | my $port = spawn $node, $initfunc, @initdata; |
| 35 | |
34 | |
| 36 | # monitoring |
35 | # monitoring |
| … | |
… | |
| 40 | |
39 | |
| 41 | =head1 CURRENT STATUS |
40 | =head1 CURRENT STATUS |
| 42 | |
41 | |
| 43 | bin/aemp - stable. |
42 | bin/aemp - stable. |
| 44 | AnyEvent::MP - stable API, should work. |
43 | AnyEvent::MP - stable API, should work. |
| 45 | AnyEvent::MP::Intro - uptodate, but incomplete. |
44 | AnyEvent::MP::Intro - explains most concepts. |
| 46 | AnyEvent::MP::Kernel - mostly stable. |
45 | AnyEvent::MP::Kernel - mostly stable. |
| 47 | AnyEvent::MP::Global - stable API, protocol not yet final. |
46 | AnyEvent::MP::Global - stable API, protocol not yet final. |
| 48 | |
47 | |
| 49 | stay tuned. |
48 | stay tuned. |
| 50 | |
49 | |
| … | |
… | |
| 55 | Despite its simplicity, you can securely message other processes running |
54 | Despite its simplicity, you can securely message other processes running |
| 56 | on the same or other hosts, and you can supervise entities remotely. |
55 | on the same or other hosts, and you can supervise entities remotely. |
| 57 | |
56 | |
| 58 | For an introduction to this module family, see the L<AnyEvent::MP::Intro> |
57 | For an introduction to this module family, see the L<AnyEvent::MP::Intro> |
| 59 | manual page and the examples under F<eg/>. |
58 | manual page and the examples under F<eg/>. |
| 60 | |
|
|
| 61 | At the moment, this module family is a bit underdocumented. |
|
|
| 62 | |
59 | |
| 63 | =head1 CONCEPTS |
60 | =head1 CONCEPTS |
| 64 | |
61 | |
| 65 | =over 4 |
62 | =over 4 |
| 66 | |
63 | |
| … | |
… | |
| 138 | |
135 | |
| 139 | our $VERSION = $AnyEvent::MP::Kernel::VERSION; |
136 | our $VERSION = $AnyEvent::MP::Kernel::VERSION; |
| 140 | |
137 | |
| 141 | our @EXPORT = qw( |
138 | our @EXPORT = qw( |
| 142 | NODE $NODE *SELF node_of after |
139 | NODE $NODE *SELF node_of after |
| 143 | initialise_node |
140 | configure |
| 144 | snd rcv mon mon_guard kil reg psub spawn |
141 | snd rcv mon mon_guard kil reg psub spawn |
| 145 | port |
142 | port |
| 146 | ); |
143 | ); |
| 147 | |
144 | |
| 148 | our $SELF; |
145 | our $SELF; |
| … | |
… | |
| 155 | |
152 | |
| 156 | =item $thisnode = NODE / $NODE |
153 | =item $thisnode = NODE / $NODE |
| 157 | |
154 | |
| 158 | The C<NODE> function returns, and the C<$NODE> variable contains, the node |
155 | The C<NODE> function returns, and the C<$NODE> variable contains, the node |
| 159 | ID of the node running in the current process. This value is initialised by |
156 | ID of the node running in the current process. This value is initialised by |
| 160 | a call to C<initialise_node>. |
157 | a call to C<configure>. |
| 161 | |
158 | |
| 162 | =item $nodeid = node_of $port |
159 | =item $nodeid = node_of $port |
| 163 | |
160 | |
| 164 | Extracts and returns the node ID from a port ID or a node ID. |
161 | Extracts and returns the node ID from a port ID or a node ID. |
| 165 | |
162 | |
| 166 | =item initialise_node $profile_name, key => value... |
163 | =item configure $profile, key => value... |
|
|
164 | |
|
|
165 | =item configure key => value... |
| 167 | |
166 | |
| 168 | Before a node can talk to other nodes on the network (i.e. enter |
167 | Before a node can talk to other nodes on the network (i.e. enter |
| 169 | "distributed mode") it has to initialise itself - the minimum a node needs |
168 | "distributed mode") it has to configure itself - the minimum a node needs |
| 170 | to know is its own name, and optionally it should know the addresses of |
169 | to know is its own name, and optionally it should know the addresses of |
| 171 | some other nodes in the network to discover other nodes. |
170 | some other nodes in the network to discover other nodes. |
| 172 | |
171 | |
| 173 | This function initialises a node - it must be called exactly once (or |
172 | This function configures a node - it must be called exactly once (or |
| 174 | never) before calling other AnyEvent::MP functions. |
173 | never) before calling other AnyEvent::MP functions. |
| 175 | |
174 | |
| 176 | The first argument is a profile name. If it is C<undef> or missing, then |
175 | =over 4 |
| 177 | the current nodename will be used instead (i.e. F<uname -n>). |
|
|
| 178 | |
176 | |
|
|
177 | =item step 1, gathering configuration from profiles |
|
|
178 | |
| 179 | The function first looks up the profile in the aemp configuration (see the |
179 | The function first looks up a profile in the aemp configuration (see the |
| 180 | L<aemp> commandline utility). the profile is calculated as follows: |
180 | L<aemp> commandline utility). The profile name can be specified via the |
|
|
181 | named C<profile> parameter or can simply be the first parameter). If it is |
|
|
182 | missing, then the nodename (F<uname -n>) will be used as profile name. |
| 181 | |
183 | |
|
|
184 | The profile data is then gathered as follows: |
|
|
185 | |
| 182 | First, all remaining key => value pairs (all of which are conviniently |
186 | First, all remaining key => value pairs (all of which are conveniently |
| 183 | undocumented at the moment) will be used. Then they will be overwritten by |
187 | undocumented at the moment) will be interpreted as configuration |
| 184 | any values specified in the global default configuration (see the F<aemp> |
188 | data. Then they will be overwritten by any values specified in the global |
| 185 | utility), then the chain of profiles selected, if any. That means that |
189 | default configuration (see the F<aemp> utility), then the chain of |
|
|
190 | profiles chosen by the profile name (and any C<parent> attributes). |
|
|
191 | |
| 186 | the values specified in the profile have highest priority and the values |
192 | That means that the values specified in the profile have highest priority |
| 187 | specified via C<initialise_node> have lowest priority. |
193 | and the values specified directly via C<configure> have lowest priority, |
|
|
194 | and can only be used to specify defaults. |
| 188 | |
195 | |
| 189 | If the profile specifies a node ID, then this will become the node ID of |
196 | If the profile specifies a node ID, then this will become the node ID of |
| 190 | this process. If not, then the profile name will be used as node ID. The |
197 | this process. If not, then the profile name will be used as node ID. The |
| 191 | special node ID of C<anon/> will be replaced by a random node ID. |
198 | special node ID of C<anon/> will be replaced by a random node ID. |
|
|
199 | |
|
|
200 | =item step 2, bind listener sockets |
| 192 | |
201 | |
| 193 | The next step is to look up the binds in the profile, followed by binding |
202 | The next step is to look up the binds in the profile, followed by binding |
| 194 | aemp protocol listeners on all binds specified (it is possible and valid |
203 | aemp protocol listeners on all binds specified (it is possible and valid |
| 195 | to have no binds, meaning that the node cannot be contacted form the |
204 | to have no binds, meaning that the node cannot be contacted form the |
| 196 | outside. This means the node cannot talk to other nodes that also have no |
205 | outside. This means the node cannot talk to other nodes that also have no |
| 197 | binds, but it can still talk to all "normal" nodes). |
206 | binds, but it can still talk to all "normal" nodes). |
| 198 | |
207 | |
| 199 | If the profile does not specify a binds list, then a default of C<*> is |
208 | If the profile does not specify a binds list, then a default of C<*> is |
| 200 | used. |
209 | used, meaning the node will bind on a dynamically-assigned port on every |
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|
210 | local IP address it finds. |
| 201 | |
211 | |
|
|
212 | =item step 3, connect to seed nodes |
|
|
213 | |
| 202 | Lastly, the seeds list from the profile is passed to the |
214 | As the last step, the seeds list from the profile is passed to the |
| 203 | L<AnyEvent::MP::Global> module, which will then use it to keep |
215 | L<AnyEvent::MP::Global> module, which will then use it to keep |
| 204 | connectivity with at least on of those seed nodes at any point in time. |
216 | connectivity with at least one node at any point in time. |
| 205 | |
217 | |
| 206 | Example: become a distributed node listening on the guessed noderef, or |
218 | =back |
| 207 | the one specified via C<aemp> for the current node. This should be the |
219 | |
|
|
220 | Example: become a distributed node using the locla node name as profile. |
| 208 | most common form of invocation for "daemon"-type nodes. |
221 | This should be the most common form of invocation for "daemon"-type nodes. |
| 209 | |
222 | |
| 210 | initialise_node; |
223 | configure |
| 211 | |
224 | |
| 212 | Example: become an anonymous node. This form is often used for commandline |
225 | Example: become an anonymous node. This form is often used for commandline |
| 213 | clients. |
226 | clients. |
| 214 | |
227 | |
| 215 | initialise_node "anon/"; |
228 | configure nodeid => "anon/"; |
| 216 | |
229 | |
| 217 | Example: become a distributed node. If there is no profile of the given |
230 | Example: configure a node using a profile called seed, which si suitable |
| 218 | name, or no binds list was specified, resolve C<localhost:4044> and bind |
231 | for a seed node as it binds on all local addresses on a fixed port (4040, |
| 219 | on the resulting addresses. |
232 | customary for aemp). |
| 220 | |
233 | |
| 221 | initialise_node "localhost:4044"; |
234 | # use the aemp commandline utility |
|
|
235 | # aemp profile seed nodeid anon/ binds '*:4040' |
|
|
236 | |
|
|
237 | # then use it |
|
|
238 | configure profile => "seed"; |
|
|
239 | |
|
|
240 | # or simply use aemp from the shell again: |
|
|
241 | # aemp run profile seed |
|
|
242 | |
|
|
243 | # or provide a nicer-to-remember nodeid |
|
|
244 | # aemp run profile seed nodeid "$(hostname)" |
| 222 | |
245 | |
| 223 | =item $SELF |
246 | =item $SELF |
| 224 | |
247 | |
| 225 | Contains the current port id while executing C<rcv> callbacks or C<psub> |
248 | Contains the current port id while executing C<rcv> callbacks or C<psub> |
| 226 | blocks. |
249 | blocks. |
| … | |
… | |
| 348 | |
371 | |
| 349 | =cut |
372 | =cut |
| 350 | |
373 | |
| 351 | sub rcv($@) { |
374 | sub rcv($@) { |
| 352 | my $port = shift; |
375 | my $port = shift; |
| 353 | my ($noderef, $portid) = split /#/, $port, 2; |
376 | my ($nodeid, $portid) = split /#/, $port, 2; |
| 354 | |
377 | |
| 355 | $NODE{$noderef} == $NODE{""} |
378 | $NODE{$nodeid} == $NODE{""} |
| 356 | or Carp::croak "$port: rcv can only be called on local ports, caught"; |
379 | or Carp::croak "$port: rcv can only be called on local ports, caught"; |
| 357 | |
380 | |
| 358 | while (@_) { |
381 | while (@_) { |
| 359 | if (ref $_[0]) { |
382 | if (ref $_[0]) { |
| 360 | if (my $self = $PORT_DATA{$portid}) { |
383 | if (my $self = $PORT_DATA{$portid}) { |
| … | |
… | |
| 468 | number of C<@reason> elements (no @reason means that the port was deleted |
491 | number of C<@reason> elements (no @reason means that the port was deleted |
| 469 | "normally"). Note also that I<< the callback B<must> never die >>, so use |
492 | "normally"). Note also that I<< the callback B<must> never die >>, so use |
| 470 | C<eval> if unsure. |
493 | C<eval> if unsure. |
| 471 | |
494 | |
| 472 | In the second form (another port given), the other port (C<$rcvport>) |
495 | In the second form (another port given), the other port (C<$rcvport>) |
| 473 | will be C<kil>'ed with C<@reason>, iff a @reason was specified, i.e. on |
496 | will be C<kil>'ed with C<@reason>, if a @reason was specified, i.e. on |
| 474 | "normal" kils nothing happens, while under all other conditions, the other |
497 | "normal" kils nothing happens, while under all other conditions, the other |
| 475 | port is killed with the same reason. |
498 | port is killed with the same reason. |
| 476 | |
499 | |
| 477 | The third form (kill self) is the same as the second form, except that |
500 | The third form (kill self) is the same as the second form, except that |
| 478 | C<$rvport> defaults to C<$SELF>. |
501 | C<$rvport> defaults to C<$SELF>. |
| … | |
… | |
| 481 | C<snd>. |
504 | C<snd>. |
| 482 | |
505 | |
| 483 | As a rule of thumb, monitoring requests should always monitor a port from |
506 | As a rule of thumb, monitoring requests should always monitor a port from |
| 484 | a local port (or callback). The reason is that kill messages might get |
507 | a local port (or callback). The reason is that kill messages might get |
| 485 | lost, just like any other message. Another less obvious reason is that |
508 | lost, just like any other message. Another less obvious reason is that |
| 486 | even monitoring requests can get lost (for exmaple, when the connection |
509 | even monitoring requests can get lost (for example, when the connection |
| 487 | to the other node goes down permanently). When monitoring a port locally |
510 | to the other node goes down permanently). When monitoring a port locally |
| 488 | these problems do not exist. |
511 | these problems do not exist. |
| 489 | |
512 | |
| 490 | Example: call a given callback when C<$port> is killed. |
513 | Example: call a given callback when C<$port> is killed. |
| 491 | |
514 | |
| … | |
… | |
| 500 | mon $port, $self => "restart"; |
523 | mon $port, $self => "restart"; |
| 501 | |
524 | |
| 502 | =cut |
525 | =cut |
| 503 | |
526 | |
| 504 | sub mon { |
527 | sub mon { |
| 505 | my ($noderef, $port) = split /#/, shift, 2; |
528 | my ($nodeid, $port) = split /#/, shift, 2; |
| 506 | |
529 | |
| 507 | my $node = $NODE{$noderef} || add_node $noderef; |
530 | my $node = $NODE{$nodeid} || add_node $nodeid; |
| 508 | |
531 | |
| 509 | my $cb = @_ ? shift : $SELF || Carp::croak 'mon: called with one argument only, but $SELF not set,'; |
532 | my $cb = @_ ? shift : $SELF || Carp::croak 'mon: called with one argument only, but $SELF not set,'; |
| 510 | |
533 | |
| 511 | unless (ref $cb) { |
534 | unless (ref $cb) { |
| 512 | if (@_) { |
535 | if (@_) { |
| … | |
… | |
| 626 | }; |
649 | }; |
| 627 | _self_die if $@; |
650 | _self_die if $@; |
| 628 | } |
651 | } |
| 629 | |
652 | |
| 630 | sub spawn(@) { |
653 | sub spawn(@) { |
| 631 | my ($noderef, undef) = split /#/, shift, 2; |
654 | my ($nodeid, undef) = split /#/, shift, 2; |
| 632 | |
655 | |
| 633 | my $id = "$RUNIQ." . $ID++; |
656 | my $id = "$RUNIQ." . $ID++; |
| 634 | |
657 | |
| 635 | $_[0] =~ /::/ |
658 | $_[0] =~ /::/ |
| 636 | or Carp::croak "spawn init function must be a fully-qualified name, caught"; |
659 | or Carp::croak "spawn init function must be a fully-qualified name, caught"; |
| 637 | |
660 | |
| 638 | snd_to_func $noderef, "AnyEvent::MP::_spawn" => $id, @_; |
661 | snd_to_func $nodeid, "AnyEvent::MP::_spawn" => $id, @_; |
| 639 | |
662 | |
| 640 | "$noderef#$id" |
663 | "$nodeid#$id" |
| 641 | } |
664 | } |
| 642 | |
665 | |
| 643 | =item after $timeout, @msg |
666 | =item after $timeout, @msg |
| 644 | |
667 | |
| 645 | =item after $timeout, $callback |
668 | =item after $timeout, $callback |
| … | |
… | |
| 684 | |
707 | |
| 685 | =item * Node IDs are arbitrary strings in AEMP. |
708 | =item * Node IDs are arbitrary strings in AEMP. |
| 686 | |
709 | |
| 687 | Erlang relies on special naming and DNS to work everywhere in the same |
710 | Erlang relies on special naming and DNS to work everywhere in the same |
| 688 | way. AEMP relies on each node somehow knowing its own address(es) (e.g. by |
711 | way. AEMP relies on each node somehow knowing its own address(es) (e.g. by |
| 689 | configuraiton or DNS), but will otherwise discover other odes itself. |
712 | configuration or DNS), but will otherwise discover other odes itself. |
| 690 | |
713 | |
| 691 | =item * Erlang has a "remote ports are like local ports" philosophy, AEMP |
714 | =item * Erlang has a "remote ports are like local ports" philosophy, AEMP |
| 692 | uses "local ports are like remote ports". |
715 | uses "local ports are like remote ports". |
| 693 | |
716 | |
| 694 | The failure modes for local ports are quite different (runtime errors |
717 | The failure modes for local ports are quite different (runtime errors |
| … | |
… | |
| 707 | |
730 | |
| 708 | Erlang uses processes that selectively receive messages, and therefore |
731 | Erlang uses processes that selectively receive messages, and therefore |
| 709 | needs a queue. AEMP is event based, queuing messages would serve no |
732 | needs a queue. AEMP is event based, queuing messages would serve no |
| 710 | useful purpose. For the same reason the pattern-matching abilities of |
733 | useful purpose. For the same reason the pattern-matching abilities of |
| 711 | AnyEvent::MP are more limited, as there is little need to be able to |
734 | AnyEvent::MP are more limited, as there is little need to be able to |
| 712 | filter messages without dequeing them. |
735 | filter messages without dequeuing them. |
| 713 | |
736 | |
| 714 | (But see L<Coro::MP> for a more Erlang-like process model on top of AEMP). |
737 | (But see L<Coro::MP> for a more Erlang-like process model on top of AEMP). |
| 715 | |
738 | |
| 716 | =item * Erlang sends are synchronous, AEMP sends are asynchronous. |
739 | =item * Erlang sends are synchronous, AEMP sends are asynchronous. |
| 717 | |
740 | |
