… | |
… | |
30 | rcv $port, pong => sub { warn "pong received\n" }; |
30 | rcv $port, pong => sub { warn "pong received\n" }; |
31 | |
31 | |
32 | # create a port on another node |
32 | # create a port on another node |
33 | my $port = spawn $node, $initfunc, @initdata; |
33 | my $port = spawn $node, $initfunc, @initdata; |
34 | |
34 | |
|
|
35 | # destroy a port again |
|
|
36 | kil $port; # "normal" kill |
|
|
37 | kil $port, my_error => "everything is broken"; # error kill |
|
|
38 | |
35 | # monitoring |
39 | # monitoring |
36 | mon $localport, $cb->(@msg) # callback is invoked on death |
40 | mon $localport, $cb->(@msg) # callback is invoked on death |
37 | mon $localport, $otherport # kill otherport on abnormal death |
41 | mon $localport, $otherport # kill otherport on abnormal death |
38 | mon $localport, $otherport, @msg # send message on death |
42 | mon $localport, $otherport, @msg # send message on death |
|
|
43 | |
|
|
44 | # temporarily execute code in port context |
|
|
45 | peval $port, sub { die "kill the port!" }; |
|
|
46 | |
|
|
47 | # execute callbacks in $SELF port context |
|
|
48 | my $timer = AE::timer 1, 0, psub { |
|
|
49 | die "kill the port, delayed"; |
|
|
50 | }; |
39 | |
51 | |
40 | =head1 CURRENT STATUS |
52 | =head1 CURRENT STATUS |
41 | |
53 | |
42 | bin/aemp - stable. |
54 | bin/aemp - stable. |
43 | AnyEvent::MP - stable API, should work. |
55 | AnyEvent::MP - stable API, should work. |
… | |
… | |
66 | |
78 | |
67 | Ports allow you to register C<rcv> handlers that can match all or just |
79 | Ports allow you to register C<rcv> handlers that can match all or just |
68 | some messages. Messages send to ports will not be queued, regardless of |
80 | some messages. Messages send to ports will not be queued, regardless of |
69 | anything was listening for them or not. |
81 | anything was listening for them or not. |
70 | |
82 | |
|
|
83 | Ports are represented by (printable) strings called "port IDs". |
|
|
84 | |
71 | =item port ID - C<nodeid#portname> |
85 | =item port ID - C<nodeid#portname> |
72 | |
86 | |
73 | A port ID is the concatenation of a node ID, a hash-mark (C<#>) as |
87 | A port ID is the concatenation of a node ID, a hash-mark (C<#>) as |
74 | separator, and a port name (a printable string of unspecified format). |
88 | separator, and a port name (a printable string of unspecified format). |
75 | |
89 | |
… | |
… | |
79 | which enables nodes to manage each other remotely, and to create new |
93 | which enables nodes to manage each other remotely, and to create new |
80 | ports. |
94 | ports. |
81 | |
95 | |
82 | Nodes are either public (have one or more listening ports) or private |
96 | Nodes are either public (have one or more listening ports) or private |
83 | (no listening ports). Private nodes cannot talk to other private nodes |
97 | (no listening ports). Private nodes cannot talk to other private nodes |
84 | currently. |
98 | currently, but all nodes can talk to public nodes. |
85 | |
99 | |
|
|
100 | Nodes is represented by (printable) strings called "node IDs". |
|
|
101 | |
86 | =item node ID - C<[A-Z_][a-zA-Z0-9_\-.:]*> |
102 | =item node ID - C<[A-Za-z0-9_\-.:]*> |
87 | |
103 | |
88 | A node ID is a string that uniquely identifies the node within a |
104 | A node ID is a string that uniquely identifies the node within a |
89 | network. Depending on the configuration used, node IDs can look like a |
105 | network. Depending on the configuration used, node IDs can look like a |
90 | hostname, a hostname and a port, or a random string. AnyEvent::MP itself |
106 | hostname, a hostname and a port, or a random string. AnyEvent::MP itself |
91 | doesn't interpret node IDs in any way. |
107 | doesn't interpret node IDs in any way except to uniquely identify a node. |
92 | |
108 | |
93 | =item binds - C<ip:port> |
109 | =item binds - C<ip:port> |
94 | |
110 | |
95 | Nodes can only talk to each other by creating some kind of connection to |
111 | Nodes can only talk to each other by creating some kind of connection to |
96 | each other. To do this, nodes should listen on one or more local transport |
112 | each other. To do this, nodes should listen on one or more local transport |
|
|
113 | endpoints - binds. |
|
|
114 | |
97 | endpoints - binds. Currently, only standard C<ip:port> specifications can |
115 | Currently, only standard C<ip:port> specifications can be used, which |
98 | be used, which specify TCP ports to listen on. |
116 | specify TCP ports to listen on. So a bind is basically just a tcp socket |
|
|
117 | in listening mode thta accepts conenctions form other nodes. |
99 | |
118 | |
100 | =item seed nodes |
119 | =item seed nodes |
101 | |
120 | |
102 | When a node starts, it knows nothing about the network. To teach the node |
121 | When a node starts, it knows nothing about the network it is in - it |
103 | about the network it first has to contact some other node within the |
122 | needs to connect to at least one other node that is already in the |
104 | network. This node is called a seed. |
123 | network. These other nodes are called "seed nodes". |
105 | |
124 | |
106 | Apart from the fact that other nodes know them as seed nodes and they have |
125 | Seed nodes themselves are not special - they are seed nodes only because |
107 | to have fixed listening addresses, seed nodes are perfectly normal nodes - |
126 | some other node I<uses> them as such, but any node can be used as seed |
108 | any node can function as a seed node for others. |
127 | node for other nodes, and eahc node cna use a different set of seed nodes. |
109 | |
128 | |
110 | In addition to discovering the network, seed nodes are also used to |
129 | In addition to discovering the network, seed nodes are also used to |
111 | maintain the network and to connect nodes that otherwise would have |
130 | maintain the network - all nodes using the same seed node form are part of |
112 | trouble connecting. They form the backbone of an AnyEvent::MP network. |
131 | the same network. If a network is split into multiple subnets because e.g. |
|
|
132 | the network link between the parts goes down, then using the same seed |
|
|
133 | nodes for all nodes ensures that eventually the subnets get merged again. |
113 | |
134 | |
114 | Seed nodes are expected to be long-running, and at least one seed node |
135 | Seed nodes are expected to be long-running, and at least one seed node |
115 | should always be available. They should also be relatively responsive - a |
136 | should always be available. They should also be relatively responsive - a |
116 | seed node that blocks for long periods will slow down everybody else. |
137 | seed node that blocks for long periods will slow down everybody else. |
117 | |
138 | |
|
|
139 | For small networks, it's best if every node uses the same set of seed |
|
|
140 | nodes. For large networks, it can be useful to specify "regional" seed |
|
|
141 | nodes for most nodes in an area, and use all seed nodes as seed nodes for |
|
|
142 | each other. What's important is that all seed nodes connections form a |
|
|
143 | complete graph, so that the network cannot split into separate subnets |
|
|
144 | forever. |
|
|
145 | |
|
|
146 | Seed nodes are represented by seed IDs. |
|
|
147 | |
118 | =item seeds - C<host:port> |
148 | =item seed IDs - C<host:port> |
119 | |
149 | |
120 | Seeds are transport endpoint(s) (usually a hostname/IP address and a |
150 | Seed IDs are transport endpoint(s) (usually a hostname/IP address and a |
121 | TCP port) of nodes that should be used as seed nodes. |
151 | TCP port) of nodes that should be used as seed nodes. |
122 | |
152 | |
123 | The nodes listening on those endpoints are expected to be long-running, |
153 | =item global nodes |
124 | and at least one of those should always be available. When nodes run out |
154 | |
125 | of connections (e.g. due to a network error), they try to re-establish |
155 | An AEMP network needs a discovery service - nodes need to know how to |
126 | connections to some seednodes again to join the network. |
156 | connect to other nodes they only know by name. In addition, AEMP offers a |
|
|
157 | distributed "group database", which maps group names to a list of strings |
|
|
158 | - for example, to register worker ports. |
|
|
159 | |
|
|
160 | A network needs at least one global node to work, and allows every node to |
|
|
161 | be a global node. |
|
|
162 | |
|
|
163 | Any node that loads the L<AnyEvent::MP::Global> module becomes a global |
|
|
164 | node and tries to keep connections to all other nodes. So while it can |
|
|
165 | make sense to make every node "global" in small networks, it usually makes |
|
|
166 | sense to only make seed nodes into global nodes in large networks (nodes |
|
|
167 | keep connections to seed nodes and global nodes, so makign them the same |
|
|
168 | reduces overhead). |
127 | |
169 | |
128 | =back |
170 | =back |
129 | |
171 | |
130 | =head1 VARIABLES/FUNCTIONS |
172 | =head1 VARIABLES/FUNCTIONS |
131 | |
173 | |
… | |
… | |
143 | |
185 | |
144 | use AE (); |
186 | use AE (); |
145 | |
187 | |
146 | use base "Exporter"; |
188 | use base "Exporter"; |
147 | |
189 | |
148 | our $VERSION = 1.2; |
190 | our $VERSION = '1.30'; |
149 | |
191 | |
150 | our @EXPORT = qw( |
192 | our @EXPORT = qw( |
151 | NODE $NODE *SELF node_of after |
193 | NODE $NODE *SELF node_of after |
152 | configure |
194 | configure |
153 | snd rcv mon mon_guard kil psub spawn cal |
195 | snd rcv mon mon_guard kil psub peval spawn cal |
154 | port |
196 | port |
155 | ); |
197 | ); |
156 | |
198 | |
157 | our $SELF; |
199 | our $SELF; |
158 | |
200 | |
… | |
… | |
178 | |
220 | |
179 | Before a node can talk to other nodes on the network (i.e. enter |
221 | Before a node can talk to other nodes on the network (i.e. enter |
180 | "distributed mode") it has to configure itself - the minimum a node needs |
222 | "distributed mode") it has to configure itself - the minimum a node needs |
181 | to know is its own name, and optionally it should know the addresses of |
223 | to know is its own name, and optionally it should know the addresses of |
182 | some other nodes in the network to discover other nodes. |
224 | some other nodes in the network to discover other nodes. |
|
|
225 | |
|
|
226 | The key/value pairs are basically the same ones as documented for the |
|
|
227 | F<aemp> command line utility (sans the set/del prefix). |
183 | |
228 | |
184 | This function configures a node - it must be called exactly once (or |
229 | This function configures a node - it must be called exactly once (or |
185 | never) before calling other AnyEvent::MP functions. |
230 | never) before calling other AnyEvent::MP functions. |
186 | |
231 | |
187 | =over 4 |
232 | =over 4 |
… | |
… | |
221 | used, meaning the node will bind on a dynamically-assigned port on every |
266 | used, meaning the node will bind on a dynamically-assigned port on every |
222 | local IP address it finds. |
267 | local IP address it finds. |
223 | |
268 | |
224 | =item step 3, connect to seed nodes |
269 | =item step 3, connect to seed nodes |
225 | |
270 | |
226 | As the last step, the seeds list from the profile is passed to the |
271 | As the last step, the seed ID list from the profile is passed to the |
227 | L<AnyEvent::MP::Global> module, which will then use it to keep |
272 | L<AnyEvent::MP::Global> module, which will then use it to keep |
228 | connectivity with at least one node at any point in time. |
273 | connectivity with at least one node at any point in time. |
229 | |
274 | |
230 | =back |
275 | =back |
231 | |
276 | |
… | |
… | |
237 | Example: become an anonymous node. This form is often used for commandline |
282 | Example: become an anonymous node. This form is often used for commandline |
238 | clients. |
283 | clients. |
239 | |
284 | |
240 | configure nodeid => "anon/"; |
285 | configure nodeid => "anon/"; |
241 | |
286 | |
242 | Example: configure a node using a profile called seed, which si suitable |
287 | Example: configure a node using a profile called seed, which is suitable |
243 | for a seed node as it binds on all local addresses on a fixed port (4040, |
288 | for a seed node as it binds on all local addresses on a fixed port (4040, |
244 | customary for aemp). |
289 | customary for aemp). |
245 | |
290 | |
246 | # use the aemp commandline utility |
291 | # use the aemp commandline utility |
247 | # aemp profile seed nodeid anon/ binds '*:4040' |
292 | # aemp profile seed nodeid anon/ binds '*:4040' |
… | |
… | |
371 | msg1 => sub { ... }, |
416 | msg1 => sub { ... }, |
372 | ... |
417 | ... |
373 | ; |
418 | ; |
374 | |
419 | |
375 | Example: temporarily register a rcv callback for a tag matching some port |
420 | Example: temporarily register a rcv callback for a tag matching some port |
376 | (e.g. for a rpc reply) and unregister it after a message was received. |
421 | (e.g. for an rpc reply) and unregister it after a message was received. |
377 | |
422 | |
378 | rcv $port, $otherport => sub { |
423 | rcv $port, $otherport => sub { |
379 | my @reply = @_; |
424 | my @reply = @_; |
380 | |
425 | |
381 | rcv $SELF, $otherport; |
426 | rcv $SELF, $otherport; |
… | |
… | |
394 | if (ref $_[0]) { |
439 | if (ref $_[0]) { |
395 | if (my $self = $PORT_DATA{$portid}) { |
440 | if (my $self = $PORT_DATA{$portid}) { |
396 | "AnyEvent::MP::Port" eq ref $self |
441 | "AnyEvent::MP::Port" eq ref $self |
397 | or Carp::croak "$port: rcv can only be called on message matching ports, caught"; |
442 | or Carp::croak "$port: rcv can only be called on message matching ports, caught"; |
398 | |
443 | |
399 | $self->[2] = shift; |
444 | $self->[0] = shift; |
400 | } else { |
445 | } else { |
401 | my $cb = shift; |
446 | my $cb = shift; |
402 | $PORT{$portid} = sub { |
447 | $PORT{$portid} = sub { |
403 | local $SELF = $port; |
448 | local $SELF = $port; |
404 | eval { &$cb }; _self_die if $@; |
449 | eval { &$cb }; _self_die if $@; |
405 | }; |
450 | }; |
406 | } |
451 | } |
407 | } elsif (defined $_[0]) { |
452 | } elsif (defined $_[0]) { |
408 | my $self = $PORT_DATA{$portid} ||= do { |
453 | my $self = $PORT_DATA{$portid} ||= do { |
409 | my $self = bless [$PORT{$port} || sub { }, { }, $port], "AnyEvent::MP::Port"; |
454 | my $self = bless [$PORT{$portid} || sub { }, { }, $port], "AnyEvent::MP::Port"; |
410 | |
455 | |
411 | $PORT{$portid} = sub { |
456 | $PORT{$portid} = sub { |
412 | local $SELF = $port; |
457 | local $SELF = $port; |
413 | |
458 | |
414 | if (my $cb = $self->[1]{$_[0]}) { |
459 | if (my $cb = $self->[1]{$_[0]}) { |
… | |
… | |
436 | } |
481 | } |
437 | |
482 | |
438 | $port |
483 | $port |
439 | } |
484 | } |
440 | |
485 | |
|
|
486 | =item peval $port, $coderef[, @args] |
|
|
487 | |
|
|
488 | Evaluates the given C<$codref> within the contetx of C<$port>, that is, |
|
|
489 | when the code throews an exception the C<$port> will be killed. |
|
|
490 | |
|
|
491 | Any remaining args will be passed to the callback. Any return values will |
|
|
492 | be returned to the caller. |
|
|
493 | |
|
|
494 | This is useful when you temporarily want to execute code in the context of |
|
|
495 | a port. |
|
|
496 | |
|
|
497 | Example: create a port and run some initialisation code in it's context. |
|
|
498 | |
|
|
499 | my $port = port { ... }; |
|
|
500 | |
|
|
501 | peval $port, sub { |
|
|
502 | init |
|
|
503 | or die "unable to init"; |
|
|
504 | }; |
|
|
505 | |
|
|
506 | =cut |
|
|
507 | |
|
|
508 | sub peval($$) { |
|
|
509 | local $SELF = shift; |
|
|
510 | my $cb = shift; |
|
|
511 | |
|
|
512 | if (wantarray) { |
|
|
513 | my @res = eval { &$cb }; |
|
|
514 | _self_die if $@; |
|
|
515 | @res |
|
|
516 | } else { |
|
|
517 | my $res = eval { &$cb }; |
|
|
518 | _self_die if $@; |
|
|
519 | $res |
|
|
520 | } |
|
|
521 | } |
|
|
522 | |
441 | =item $closure = psub { BLOCK } |
523 | =item $closure = psub { BLOCK } |
442 | |
524 | |
443 | Remembers C<$SELF> and creates a closure out of the BLOCK. When the |
525 | Remembers C<$SELF> and creates a closure out of the BLOCK. When the |
444 | closure is executed, sets up the environment in the same way as in C<rcv> |
526 | closure is executed, sets up the environment in the same way as in C<rcv> |
445 | callbacks, i.e. runtime errors will cause the port to get C<kil>ed. |
527 | callbacks, i.e. runtime errors will cause the port to get C<kil>ed. |
|
|
528 | |
|
|
529 | The effect is basically as if it returned C<< sub { peval $SELF, sub { |
|
|
530 | BLOCK }, @_ } >>. |
446 | |
531 | |
447 | This is useful when you register callbacks from C<rcv> callbacks: |
532 | This is useful when you register callbacks from C<rcv> callbacks: |
448 | |
533 | |
449 | rcv delayed_reply => sub { |
534 | rcv delayed_reply => sub { |
450 | my ($delay, @reply) = @_; |
535 | my ($delay, @reply) = @_; |
… | |
… | |
598 | |
683 | |
599 | =item kil $port[, @reason] |
684 | =item kil $port[, @reason] |
600 | |
685 | |
601 | Kill the specified port with the given C<@reason>. |
686 | Kill the specified port with the given C<@reason>. |
602 | |
687 | |
603 | If no C<@reason> is specified, then the port is killed "normally" (ports |
688 | If no C<@reason> is specified, then the port is killed "normally" - |
604 | monitoring other ports will not necessarily die because a port dies |
689 | monitor callback will be invoked, but the kil will not cause linked ports |
605 | "normally"). |
690 | (C<mon $mport, $lport> form) to get killed. |
606 | |
691 | |
607 | Otherwise, linked ports get killed with the same reason (second form of |
692 | If a C<@reason> is specified, then linked ports (C<mon $mport, $lport> |
608 | C<mon>, see above). |
693 | form) get killed with the same reason. |
609 | |
694 | |
610 | Runtime errors while evaluating C<rcv> callbacks or inside C<psub> blocks |
695 | Runtime errors while evaluating C<rcv> callbacks or inside C<psub> blocks |
611 | will be reported as reason C<< die => $@ >>. |
696 | will be reported as reason C<< die => $@ >>. |
612 | |
697 | |
613 | Transport/communication errors are reported as C<< transport_error => |
698 | Transport/communication errors are reported as C<< transport_error => |
… | |
… | |
787 | |
872 | |
788 | =item * Node IDs are arbitrary strings in AEMP. |
873 | =item * Node IDs are arbitrary strings in AEMP. |
789 | |
874 | |
790 | Erlang relies on special naming and DNS to work everywhere in the same |
875 | Erlang relies on special naming and DNS to work everywhere in the same |
791 | way. AEMP relies on each node somehow knowing its own address(es) (e.g. by |
876 | way. AEMP relies on each node somehow knowing its own address(es) (e.g. by |
792 | configuration or DNS), but will otherwise discover other odes itself. |
877 | configuration or DNS), and possibly the addresses of some seed nodes, but |
|
|
878 | will otherwise discover other nodes (and their IDs) itself. |
793 | |
879 | |
794 | =item * Erlang has a "remote ports are like local ports" philosophy, AEMP |
880 | =item * Erlang has a "remote ports are like local ports" philosophy, AEMP |
795 | uses "local ports are like remote ports". |
881 | uses "local ports are like remote ports". |
796 | |
882 | |
797 | The failure modes for local ports are quite different (runtime errors |
883 | The failure modes for local ports are quite different (runtime errors |
… | |
… | |
806 | ports being the special case/exception, where transport errors cannot |
892 | ports being the special case/exception, where transport errors cannot |
807 | occur. |
893 | occur. |
808 | |
894 | |
809 | =item * Erlang uses processes and a mailbox, AEMP does not queue. |
895 | =item * Erlang uses processes and a mailbox, AEMP does not queue. |
810 | |
896 | |
811 | Erlang uses processes that selectively receive messages, and therefore |
897 | Erlang uses processes that selectively receive messages out of order, and |
812 | needs a queue. AEMP is event based, queuing messages would serve no |
898 | therefore needs a queue. AEMP is event based, queuing messages would serve |
813 | useful purpose. For the same reason the pattern-matching abilities of |
899 | no useful purpose. For the same reason the pattern-matching abilities |
814 | AnyEvent::MP are more limited, as there is little need to be able to |
900 | of AnyEvent::MP are more limited, as there is little need to be able to |
815 | filter messages without dequeuing them. |
901 | filter messages without dequeuing them. |
816 | |
902 | |
817 | (But see L<Coro::MP> for a more Erlang-like process model on top of AEMP). |
903 | This is not a philosophical difference, but simply stems from AnyEvent::MP |
|
|
904 | being event-based, while Erlang is process-based. |
|
|
905 | |
|
|
906 | You cna have a look at L<Coro::MP> for a more Erlang-like process model on |
|
|
907 | top of AEMP and Coro threads. |
818 | |
908 | |
819 | =item * Erlang sends are synchronous, AEMP sends are asynchronous. |
909 | =item * Erlang sends are synchronous, AEMP sends are asynchronous. |
820 | |
910 | |
821 | Sending messages in Erlang is synchronous and blocks the process (and |
911 | Sending messages in Erlang is synchronous and blocks the process until |
|
|
912 | a conenction has been established and the message sent (and so does not |
822 | so does not need a queue that can overflow). AEMP sends are immediate, |
913 | need a queue that can overflow). AEMP sends return immediately, connection |
823 | connection establishment is handled in the background. |
914 | establishment is handled in the background. |
824 | |
915 | |
825 | =item * Erlang suffers from silent message loss, AEMP does not. |
916 | =item * Erlang suffers from silent message loss, AEMP does not. |
826 | |
917 | |
827 | Erlang makes few guarantees on messages delivery - messages can get lost |
918 | Erlang implements few guarantees on messages delivery - messages can get |
828 | without any of the processes realising it (i.e. you send messages a, b, |
919 | lost without any of the processes realising it (i.e. you send messages a, |
829 | and c, and the other side only receives messages a and c). |
920 | b, and c, and the other side only receives messages a and c). |
830 | |
921 | |
831 | AEMP guarantees correct ordering, and the guarantee that after one message |
922 | AEMP guarantees (modulo hardware errors) correct ordering, and the |
832 | is lost, all following ones sent to the same port are lost as well, until |
923 | guarantee that after one message is lost, all following ones sent to the |
833 | monitoring raises an error, so there are no silent "holes" in the message |
924 | same port are lost as well, until monitoring raises an error, so there are |
834 | sequence. |
925 | no silent "holes" in the message sequence. |
|
|
926 | |
|
|
927 | If you want your software to be very reliable, you have to cope with |
|
|
928 | corrupted and even out-of-order messages in both Erlang and AEMP. AEMP |
|
|
929 | simply tries to work better in common error cases, such as when a network |
|
|
930 | link goes down. |
835 | |
931 | |
836 | =item * Erlang can send messages to the wrong port, AEMP does not. |
932 | =item * Erlang can send messages to the wrong port, AEMP does not. |
837 | |
933 | |
838 | In Erlang it is quite likely that a node that restarts reuses a process ID |
934 | In Erlang it is quite likely that a node that restarts reuses an Erlang |
839 | known to other nodes for a completely different process, causing messages |
935 | process ID known to other nodes for a completely different process, |
840 | destined for that process to end up in an unrelated process. |
936 | causing messages destined for that process to end up in an unrelated |
|
|
937 | process. |
841 | |
938 | |
842 | AEMP never reuses port IDs, so old messages or old port IDs floating |
939 | AEMP does not reuse port IDs, so old messages or old port IDs floating |
843 | around in the network will not be sent to an unrelated port. |
940 | around in the network will not be sent to an unrelated port. |
844 | |
941 | |
845 | =item * Erlang uses unprotected connections, AEMP uses secure |
942 | =item * Erlang uses unprotected connections, AEMP uses secure |
846 | authentication and can use TLS. |
943 | authentication and can use TLS. |
847 | |
944 | |
… | |
… | |
850 | |
947 | |
851 | =item * The AEMP protocol is optimised for both text-based and binary |
948 | =item * The AEMP protocol is optimised for both text-based and binary |
852 | communications. |
949 | communications. |
853 | |
950 | |
854 | The AEMP protocol, unlike the Erlang protocol, supports both programming |
951 | The AEMP protocol, unlike the Erlang protocol, supports both programming |
855 | language independent text-only protocols (good for debugging) and binary, |
952 | language independent text-only protocols (good for debugging), and binary, |
856 | language-specific serialisers (e.g. Storable). By default, unless TLS is |
953 | language-specific serialisers (e.g. Storable). By default, unless TLS is |
857 | used, the protocol is actually completely text-based. |
954 | used, the protocol is actually completely text-based. |
858 | |
955 | |
859 | It has also been carefully designed to be implementable in other languages |
956 | It has also been carefully designed to be implementable in other languages |
860 | with a minimum of work while gracefully degrading functionality to make the |
957 | with a minimum of work while gracefully degrading functionality to make the |
861 | protocol simple. |
958 | protocol simple. |
862 | |
959 | |
863 | =item * AEMP has more flexible monitoring options than Erlang. |
960 | =item * AEMP has more flexible monitoring options than Erlang. |
864 | |
961 | |
865 | In Erlang, you can chose to receive I<all> exit signals as messages |
962 | In Erlang, you can chose to receive I<all> exit signals as messages or |
866 | or I<none>, there is no in-between, so monitoring single processes is |
963 | I<none>, there is no in-between, so monitoring single Erlang processes is |
867 | difficult to implement. Monitoring in AEMP is more flexible than in |
964 | difficult to implement. |
868 | Erlang, as one can choose between automatic kill, exit message or callback |
965 | |
869 | on a per-process basis. |
966 | Monitoring in AEMP is more flexible than in Erlang, as one can choose |
|
|
967 | between automatic kill, exit message or callback on a per-port basis. |
870 | |
968 | |
871 | =item * Erlang tries to hide remote/local connections, AEMP does not. |
969 | =item * Erlang tries to hide remote/local connections, AEMP does not. |
872 | |
970 | |
873 | Monitoring in Erlang is not an indicator of process death/crashes, in the |
971 | Monitoring in Erlang is not an indicator of process death/crashes, in the |
874 | same way as linking is (except linking is unreliable in Erlang). |
972 | same way as linking is (except linking is unreliable in Erlang). |
… | |
… | |
896 | overhead, as well as having to keep a proxy object everywhere. |
994 | overhead, as well as having to keep a proxy object everywhere. |
897 | |
995 | |
898 | Strings can easily be printed, easily serialised etc. and need no special |
996 | Strings can easily be printed, easily serialised etc. and need no special |
899 | procedures to be "valid". |
997 | procedures to be "valid". |
900 | |
998 | |
901 | And as a result, a miniport consists of a single closure stored in a |
999 | And as a result, a port with just a default receiver consists of a single |
902 | global hash - it can't become much cheaper. |
1000 | code reference stored in a global hash - it can't become much cheaper. |
903 | |
1001 | |
904 | =item Why favour JSON, why not a real serialising format such as Storable? |
1002 | =item Why favour JSON, why not a real serialising format such as Storable? |
905 | |
1003 | |
906 | In fact, any AnyEvent::MP node will happily accept Storable as framing |
1004 | In fact, any AnyEvent::MP node will happily accept Storable as framing |
907 | format, but currently there is no way to make a node use Storable by |
1005 | format, but currently there is no way to make a node use Storable by |
… | |
… | |
923 | |
1021 | |
924 | L<AnyEvent::MP::Intro> - a gentle introduction. |
1022 | L<AnyEvent::MP::Intro> - a gentle introduction. |
925 | |
1023 | |
926 | L<AnyEvent::MP::Kernel> - more, lower-level, stuff. |
1024 | L<AnyEvent::MP::Kernel> - more, lower-level, stuff. |
927 | |
1025 | |
928 | L<AnyEvent::MP::Global> - network maintainance and port groups, to find |
1026 | L<AnyEvent::MP::Global> - network maintenance and port groups, to find |
929 | your applications. |
1027 | your applications. |
|
|
1028 | |
|
|
1029 | L<AnyEvent::MP::DataConn> - establish data connections between nodes. |
930 | |
1030 | |
931 | L<AnyEvent::MP::LogCatcher> - simple service to display log messages from |
1031 | L<AnyEvent::MP::LogCatcher> - simple service to display log messages from |
932 | all nodes. |
1032 | all nodes. |
933 | |
1033 | |
934 | L<AnyEvent>. |
1034 | L<AnyEvent>. |