… | |
… | |
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 prot 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. |
… | |
… | |
116 | seed node that blocks for long periods will slow down everybody else. |
128 | seed node that blocks for long periods will slow down everybody else. |
117 | |
129 | |
118 | =item seeds - C<host:port> |
130 | =item seeds - C<host:port> |
119 | |
131 | |
120 | Seeds are transport endpoint(s) (usually a hostname/IP address and a |
132 | Seeds are transport endpoint(s) (usually a hostname/IP address and a |
121 | TCP port) of nodes thta should be used as seed nodes. |
133 | TCP port) of nodes that should be used as seed nodes. |
122 | |
134 | |
123 | The nodes listening on those endpoints are expected to be long-running, |
135 | The nodes listening on those endpoints are expected to be long-running, |
124 | and at least one of those should always be available. When nodes run out |
136 | and at least one of those should always be available. When nodes run out |
125 | of connections (e.g. due to a network error), they try to re-establish |
137 | of connections (e.g. due to a network error), they try to re-establish |
126 | connections to some seednodes again to join the network. |
138 | connections to some seednodes again to join the network. |
… | |
… | |
143 | |
155 | |
144 | use AE (); |
156 | use AE (); |
145 | |
157 | |
146 | use base "Exporter"; |
158 | use base "Exporter"; |
147 | |
159 | |
148 | our $VERSION = $AnyEvent::MP::Kernel::VERSION; |
160 | our $VERSION = 1.23; |
149 | |
161 | |
150 | our @EXPORT = qw( |
162 | our @EXPORT = qw( |
151 | NODE $NODE *SELF node_of after |
163 | NODE $NODE *SELF node_of after |
152 | configure |
164 | configure |
153 | snd rcv mon mon_guard kil psub spawn cal |
165 | snd rcv mon mon_guard kil psub peval spawn cal |
154 | port |
166 | port |
155 | ); |
167 | ); |
156 | |
168 | |
157 | our $SELF; |
169 | our $SELF; |
158 | |
170 | |
… | |
… | |
371 | msg1 => sub { ... }, |
383 | msg1 => sub { ... }, |
372 | ... |
384 | ... |
373 | ; |
385 | ; |
374 | |
386 | |
375 | Example: temporarily register a rcv callback for a tag matching some port |
387 | 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. |
388 | (e.g. for an rpc reply) and unregister it after a message was received. |
377 | |
389 | |
378 | rcv $port, $otherport => sub { |
390 | rcv $port, $otherport => sub { |
379 | my @reply = @_; |
391 | my @reply = @_; |
380 | |
392 | |
381 | rcv $SELF, $otherport; |
393 | rcv $SELF, $otherport; |
… | |
… | |
394 | if (ref $_[0]) { |
406 | if (ref $_[0]) { |
395 | if (my $self = $PORT_DATA{$portid}) { |
407 | if (my $self = $PORT_DATA{$portid}) { |
396 | "AnyEvent::MP::Port" eq ref $self |
408 | "AnyEvent::MP::Port" eq ref $self |
397 | or Carp::croak "$port: rcv can only be called on message matching ports, caught"; |
409 | or Carp::croak "$port: rcv can only be called on message matching ports, caught"; |
398 | |
410 | |
399 | $self->[2] = shift; |
411 | $self->[0] = shift; |
400 | } else { |
412 | } else { |
401 | my $cb = shift; |
413 | my $cb = shift; |
402 | $PORT{$portid} = sub { |
414 | $PORT{$portid} = sub { |
403 | local $SELF = $port; |
415 | local $SELF = $port; |
404 | eval { &$cb }; _self_die if $@; |
416 | eval { &$cb }; _self_die if $@; |
405 | }; |
417 | }; |
406 | } |
418 | } |
407 | } elsif (defined $_[0]) { |
419 | } elsif (defined $_[0]) { |
408 | my $self = $PORT_DATA{$portid} ||= do { |
420 | my $self = $PORT_DATA{$portid} ||= do { |
409 | my $self = bless [$PORT{$port} || sub { }, { }, $port], "AnyEvent::MP::Port"; |
421 | my $self = bless [$PORT{$portid} || sub { }, { }, $port], "AnyEvent::MP::Port"; |
410 | |
422 | |
411 | $PORT{$portid} = sub { |
423 | $PORT{$portid} = sub { |
412 | local $SELF = $port; |
424 | local $SELF = $port; |
413 | |
425 | |
414 | if (my $cb = $self->[1]{$_[0]}) { |
426 | if (my $cb = $self->[1]{$_[0]}) { |
… | |
… | |
436 | } |
448 | } |
437 | |
449 | |
438 | $port |
450 | $port |
439 | } |
451 | } |
440 | |
452 | |
|
|
453 | =item peval $port, $coderef[, @args] |
|
|
454 | |
|
|
455 | Evaluates the given C<$codref> within the contetx of C<$port>, that is, |
|
|
456 | when the code throews an exception the C<$port> will be killed. |
|
|
457 | |
|
|
458 | Any remaining args will be passed to the callback. Any return values will |
|
|
459 | be returned to the caller. |
|
|
460 | |
|
|
461 | This is useful when you temporarily want to execute code in the context of |
|
|
462 | a port. |
|
|
463 | |
|
|
464 | Example: create a port and run some initialisation code in it's context. |
|
|
465 | |
|
|
466 | my $port = port { ... }; |
|
|
467 | |
|
|
468 | peval $port, sub { |
|
|
469 | init |
|
|
470 | or die "unable to init"; |
|
|
471 | }; |
|
|
472 | |
|
|
473 | =cut |
|
|
474 | |
|
|
475 | sub peval($$) { |
|
|
476 | local $SELF = shift; |
|
|
477 | my $cb = shift; |
|
|
478 | |
|
|
479 | if (wantarray) { |
|
|
480 | my @res = eval { &$cb }; |
|
|
481 | _self_die if $@; |
|
|
482 | @res |
|
|
483 | } else { |
|
|
484 | my $res = eval { &$cb }; |
|
|
485 | _self_die if $@; |
|
|
486 | $res |
|
|
487 | } |
|
|
488 | } |
|
|
489 | |
441 | =item $closure = psub { BLOCK } |
490 | =item $closure = psub { BLOCK } |
442 | |
491 | |
443 | Remembers C<$SELF> and creates a closure out of the BLOCK. When the |
492 | 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> |
493 | 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. |
494 | callbacks, i.e. runtime errors will cause the port to get C<kil>ed. |
|
|
495 | |
|
|
496 | The effect is basically as if it returned C<< sub { peval $SELF, sub { |
|
|
497 | BLOCK } } >>. |
446 | |
498 | |
447 | This is useful when you register callbacks from C<rcv> callbacks: |
499 | This is useful when you register callbacks from C<rcv> callbacks: |
448 | |
500 | |
449 | rcv delayed_reply => sub { |
501 | rcv delayed_reply => sub { |
450 | my ($delay, @reply) = @_; |
502 | my ($delay, @reply) = @_; |
… | |
… | |
523 | delivered again. |
575 | delivered again. |
524 | |
576 | |
525 | Inter-host-connection timeouts and monitoring depend on the transport |
577 | Inter-host-connection timeouts and monitoring depend on the transport |
526 | used. The only transport currently implemented is TCP, and AnyEvent::MP |
578 | used. The only transport currently implemented is TCP, and AnyEvent::MP |
527 | relies on TCP to detect node-downs (this can take 10-15 minutes on a |
579 | relies on TCP to detect node-downs (this can take 10-15 minutes on a |
528 | non-idle connection, and usually around two hours for idle conenctions). |
580 | non-idle connection, and usually around two hours for idle connections). |
529 | |
581 | |
530 | This means that monitoring is good for program errors and cleaning up |
582 | This means that monitoring is good for program errors and cleaning up |
531 | stuff eventually, but they are no replacement for a timeout when you need |
583 | stuff eventually, but they are no replacement for a timeout when you need |
532 | to ensure some maximum latency. |
584 | to ensure some maximum latency. |
533 | |
585 | |
… | |
… | |
565 | } |
617 | } |
566 | |
618 | |
567 | $node->monitor ($port, $cb); |
619 | $node->monitor ($port, $cb); |
568 | |
620 | |
569 | defined wantarray |
621 | defined wantarray |
570 | and AnyEvent::Util::guard { $node->unmonitor ($port, $cb) } |
622 | and ($cb += 0, AnyEvent::Util::guard { $node->unmonitor ($port, $cb) }) |
571 | } |
623 | } |
572 | |
624 | |
573 | =item $guard = mon_guard $port, $ref, $ref... |
625 | =item $guard = mon_guard $port, $ref, $ref... |
574 | |
626 | |
575 | Monitors the given C<$port> and keeps the passed references. When the port |
627 | Monitors the given C<$port> and keeps the passed references. When the port |
… | |
… | |
727 | |
779 | |
728 | If an optional time-out (in seconds) is given and it is not C<undef>, |
780 | If an optional time-out (in seconds) is given and it is not C<undef>, |
729 | then the callback will be called without any arguments after the time-out |
781 | then the callback will be called without any arguments after the time-out |
730 | elapsed and the port is C<kil>ed. |
782 | elapsed and the port is C<kil>ed. |
731 | |
783 | |
732 | If no time-out is given, then the local port will monitor the remote port |
784 | If no time-out is given (or it is C<undef>), then the local port will |
733 | instead, so it eventually gets cleaned-up. |
785 | monitor the remote port instead, so it eventually gets cleaned-up. |
734 | |
786 | |
735 | Currently this function returns the temporary port, but this "feature" |
787 | Currently this function returns the temporary port, but this "feature" |
736 | might go in future versions unless you can make a convincing case that |
788 | might go in future versions unless you can make a convincing case that |
737 | this is indeed useful for something. |
789 | this is indeed useful for something. |
738 | |
790 | |
… | |
… | |
774 | AnyEvent::MP got lots of its ideas from distributed Erlang (Erlang node |
826 | AnyEvent::MP got lots of its ideas from distributed Erlang (Erlang node |
775 | == aemp node, Erlang process == aemp port), so many of the documents and |
827 | == aemp node, Erlang process == aemp port), so many of the documents and |
776 | programming techniques employed by Erlang apply to AnyEvent::MP. Here is a |
828 | programming techniques employed by Erlang apply to AnyEvent::MP. Here is a |
777 | sample: |
829 | sample: |
778 | |
830 | |
779 | http://www.Erlang.se/doc/programming_rules.shtml |
831 | http://www.erlang.se/doc/programming_rules.shtml |
780 | http://Erlang.org/doc/getting_started/part_frame.html # chapters 3 and 4 |
832 | http://erlang.org/doc/getting_started/part_frame.html # chapters 3 and 4 |
781 | http://Erlang.org/download/Erlang-book-part1.pdf # chapters 5 and 6 |
833 | http://erlang.org/download/erlang-book-part1.pdf # chapters 5 and 6 |
782 | http://Erlang.org/download/armstrong_thesis_2003.pdf # chapters 4 and 5 |
834 | http://erlang.org/download/armstrong_thesis_2003.pdf # chapters 4 and 5 |
783 | |
835 | |
784 | Despite the similarities, there are also some important differences: |
836 | Despite the similarities, there are also some important differences: |
785 | |
837 | |
786 | =over 4 |
838 | =over 4 |
787 | |
839 | |
788 | =item * Node IDs are arbitrary strings in AEMP. |
840 | =item * Node IDs are arbitrary strings in AEMP. |
789 | |
841 | |
790 | Erlang relies on special naming and DNS to work everywhere in the same |
842 | 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 |
843 | 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. |
844 | configuration or DNS), and possibly the addresses of some seed nodes, but |
|
|
845 | will otherwise discover other nodes (and their IDs) itself. |
793 | |
846 | |
794 | =item * Erlang has a "remote ports are like local ports" philosophy, AEMP |
847 | =item * Erlang has a "remote ports are like local ports" philosophy, AEMP |
795 | uses "local ports are like remote ports". |
848 | uses "local ports are like remote ports". |
796 | |
849 | |
797 | The failure modes for local ports are quite different (runtime errors |
850 | The failure modes for local ports are quite different (runtime errors |
… | |
… | |
822 | so does not need a queue that can overflow). AEMP sends are immediate, |
875 | so does not need a queue that can overflow). AEMP sends are immediate, |
823 | connection establishment is handled in the background. |
876 | connection establishment is handled in the background. |
824 | |
877 | |
825 | =item * Erlang suffers from silent message loss, AEMP does not. |
878 | =item * Erlang suffers from silent message loss, AEMP does not. |
826 | |
879 | |
827 | Erlang makes few guarantees on messages delivery - messages can get lost |
880 | 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, |
881 | 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). |
882 | b, and c, and the other side only receives messages a and c). |
830 | |
883 | |
831 | AEMP guarantees correct ordering, and the guarantee that after one message |
884 | AEMP guarantees correct ordering, and the guarantee that after one message |
832 | is lost, all following ones sent to the same port are lost as well, until |
885 | is lost, all following ones sent to the same port are lost as well, until |
833 | monitoring raises an error, so there are no silent "holes" in the message |
886 | monitoring raises an error, so there are no silent "holes" in the message |
834 | sequence. |
887 | sequence. |