… | |
… | |
463 | outstanding requests. It's ignored by the synchronous backend. |
463 | outstanding requests. It's ignored by the synchronous backend. |
464 | |
464 | |
465 | By overriding this you can prolong the life of a RPC process after e.g. |
465 | By overriding this you can prolong the life of a RPC process after e.g. |
466 | the parent has exited by running the event loop in the provided function |
466 | the parent has exited by running the event loop in the provided function |
467 | (or simply calling it, for example, when your child process uses L<EV> you |
467 | (or simply calling it, for example, when your child process uses L<EV> you |
468 | could provide L<EV::loop> as C<done> function). |
468 | could provide L<EV::run> as C<done> function). |
469 | |
469 | |
470 | Of course, in that case you are responsible for exiting at the appropriate |
470 | Of course, in that case you are responsible for exiting at the appropriate |
471 | time and not returning from |
471 | time and not returning from |
472 | |
472 | |
473 | =item async => $boolean (default: 0) |
473 | =item async => $boolean (default: 0) |
… | |
… | |
494 | |
494 | |
495 | All arguments, result data and event data have to be serialised to be |
495 | All arguments, result data and event data have to be serialised to be |
496 | transferred between the processes. For this, they have to be frozen and |
496 | transferred between the processes. For this, they have to be frozen and |
497 | thawed in both parent and child processes. |
497 | thawed in both parent and child processes. |
498 | |
498 | |
499 | By default, only octet strings can be passed between the processes, which |
499 | By default, only octet strings can be passed between the processes, |
500 | is reasonably fast and efficient and requires no extra modules. |
500 | which is reasonably fast and efficient and requires no extra modules |
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|
501 | (the C<AnyEvent::Fork::RPC> distribution does not provide these extra |
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|
502 | serialiser modules). |
501 | |
503 | |
502 | For more complicated use cases, you can provide your own freeze and thaw |
504 | For more complicated use cases, you can provide your own freeze and thaw |
503 | functions, by specifying a string with perl source code. It's supposed to |
505 | functions, by specifying a string with perl source code. It's supposed to |
504 | return two code references when evaluated: the first receives a list of |
506 | return two code references when evaluated: the first receives a list of |
505 | perl values and must return an octet string. The second receives the octet |
507 | perl values and must return an octet string. The second receives the octet |
… | |
… | |
507 | |
509 | |
508 | If you need an external module for serialisation, then you can either |
510 | If you need an external module for serialisation, then you can either |
509 | pre-load it into your L<AnyEvent::Fork> process, or you can add a C<use> |
511 | pre-load it into your L<AnyEvent::Fork> process, or you can add a C<use> |
510 | or C<require> statement into the serialiser string. Or both. |
512 | or C<require> statement into the serialiser string. Or both. |
511 | |
513 | |
512 | Here are some examples - some of them are also available as global |
514 | Here are some examples - all of them are also available as global |
513 | variables that make them easier to use. |
515 | variables that make them easier to use. |
514 | |
516 | |
515 | =over 4 |
517 | =over 4 |
516 | |
518 | |
517 | =item octet strings - C<$AnyEvent::Fork::RPC::STRING_SERIALISER> |
519 | =item C<$AnyEvent::Fork::RPC::STRING_SERIALISER> - octet strings only |
518 | |
520 | |
519 | This serialiser concatenates length-prefixes octet strings, and is the |
521 | This serialiser (currently the default) concatenates length-prefixes octet |
520 | default. That means you can only pass (and return) strings containing |
522 | strings, and is the default. That means you can only pass (and return) |
521 | character codes 0-255. |
523 | strings containing character codes 0-255. |
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|
524 | |
|
|
525 | The main advantages of this serialiser are the high speed and that it |
|
|
526 | doesn't need another module. The main disadvantage is that you are very |
|
|
527 | limited in what you can pass - only octet strings. |
522 | |
528 | |
523 | Implementation: |
529 | Implementation: |
524 | |
530 | |
525 | ( |
531 | ( |
526 | sub { pack "(w/a*)*", @_ }, |
532 | sub { pack "(w/a*)*", @_ }, |
527 | sub { unpack "(w/a*)*", shift } |
533 | sub { unpack "(w/a*)*", shift } |
528 | ) |
534 | ) |
529 | |
535 | |
530 | =item json - C<$AnyEvent::Fork::RPC::JSON_SERIALISER> |
536 | =item C<$AnyEvent::Fork::RPC::CBOR_XS_SERIALISER> - uses L<CBOR::XS> |
|
|
537 | |
|
|
538 | This serialiser creates CBOR::XS arrays - you have to make sure the |
|
|
539 | L<CBOR::XS> module is installed for this serialiser to work. It can be |
|
|
540 | beneficial for sharing when you preload the L<CBOR::XS> module in a template |
|
|
541 | process. |
|
|
542 | |
|
|
543 | L<CBOR::XS> is about as fast as the octet string serialiser, but supports |
|
|
544 | complex data structures (similar to JSON) and is faster than any of the |
|
|
545 | other serialisers. If you have the L<CBOR::XS> module available, it's the |
|
|
546 | best choice. |
|
|
547 | |
|
|
548 | The encoder enables C<allow_sharing> (so this serialisation method can |
|
|
549 | encode cyclic and self-referencing data structures). |
|
|
550 | |
|
|
551 | Implementation: |
|
|
552 | |
|
|
553 | use CBOR::XS (); |
|
|
554 | ( |
|
|
555 | sub { CBOR::XS::encode_cbor_sharing \@_ }, |
|
|
556 | sub { @{ CBOR::XS::decode_cbor shift } } |
|
|
557 | ) |
|
|
558 | |
|
|
559 | =item C<$AnyEvent::Fork::RPC::JSON_SERIALISER> - uses L<JSON::XS> or L<JSON> |
531 | |
560 | |
532 | This serialiser creates JSON arrays - you have to make sure the L<JSON> |
561 | This serialiser creates JSON arrays - you have to make sure the L<JSON> |
533 | module is installed for this serialiser to work. It can be beneficial for |
562 | module is installed for this serialiser to work. It can be beneficial for |
534 | sharing when you preload the L<JSON> module in a template process. |
563 | sharing when you preload the L<JSON> module in a template process. |
535 | |
564 | |
… | |
… | |
543 | ( |
572 | ( |
544 | sub { JSON::encode_json \@_ }, |
573 | sub { JSON::encode_json \@_ }, |
545 | sub { @{ JSON::decode_json shift } } |
574 | sub { @{ JSON::decode_json shift } } |
546 | ) |
575 | ) |
547 | |
576 | |
548 | =item storable - C<$AnyEvent::Fork::RPC::STORABLE_SERIALISER> |
577 | =item C<$AnyEvent::Fork::RPC::STORABLE_SERIALISER> - L<Storable> |
549 | |
578 | |
550 | This serialiser uses L<Storable>, which means it has high chance of |
579 | This serialiser uses L<Storable>, which means it has high chance of |
551 | serialising just about anything you throw at it, at the cost of having |
580 | serialising just about anything you throw at it, at the cost of having |
552 | very high overhead per operation. It also comes with perl. It should be |
581 | very high overhead per operation. It also comes with perl. It should be |
553 | used when you need to serialise complex data structures. |
582 | used when you need to serialise complex data structures. |
… | |
… | |
558 | ( |
587 | ( |
559 | sub { Storable::freeze \@_ }, |
588 | sub { Storable::freeze \@_ }, |
560 | sub { @{ Storable::thaw shift } } |
589 | sub { @{ Storable::thaw shift } } |
561 | ) |
590 | ) |
562 | |
591 | |
563 | =item portable storable - C<$AnyEvent::Fork::RPC::NSTORABLE_SERIALISER> |
592 | =item C<$AnyEvent::Fork::RPC::NSTORABLE_SERIALISER> - portable Storable |
564 | |
593 | |
565 | This serialiser also uses L<Storable>, but uses it's "network" format |
594 | This serialiser also uses L<Storable>, but uses it's "network" format |
566 | to serialise data, which makes it possible to talk to different |
595 | to serialise data, which makes it possible to talk to different |
567 | perl binaries (for example, when talking to a process created with |
596 | perl binaries (for example, when talking to a process created with |
568 | L<AnyEvent::Fork::Remote>). |
597 | L<AnyEvent::Fork::Remote>). |
… | |
… | |
583 | examples. |
612 | examples. |
584 | |
613 | |
585 | =cut |
614 | =cut |
586 | |
615 | |
587 | our $STRING_SERIALISER = '(sub { pack "(w/a*)*", @_ }, sub { unpack "(w/a*)*", shift })'; |
616 | our $STRING_SERIALISER = '(sub { pack "(w/a*)*", @_ }, sub { unpack "(w/a*)*", shift })'; |
|
|
617 | our $CBOR_XS_SERIALISER = 'use CBOR::XS (); (sub { CBOR::XS::encode_cbor_sharing \@_ }, sub { @{ CBOR::XS::decode_cbor shift } })'; |
588 | our $JSON_SERIALISER = 'use JSON (); (sub { JSON::encode_json \@_ }, sub { @{ JSON::decode_json shift } })'; |
618 | our $JSON_SERIALISER = 'use JSON (); (sub { JSON::encode_json \@_ }, sub { @{ JSON::decode_json shift } })'; |
589 | our $STORABLE_SERIALISER = 'use Storable (); (sub { Storable::freeze \@_ }, sub { @{ Storable::thaw shift } })'; |
619 | our $STORABLE_SERIALISER = 'use Storable (); (sub { Storable::freeze \@_ }, sub { @{ Storable::thaw shift } })'; |
590 | our $NSTORABLE_SERIALISER = 'use Storable (); (sub { Storable::nfreeze \@_ }, sub { @{ Storable::thaw shift } })'; |
620 | our $NSTORABLE_SERIALISER = 'use Storable (); (sub { Storable::nfreeze \@_ }, sub { @{ Storable::thaw shift } })'; |
591 | |
621 | |
592 | sub run { |
622 | sub run { |
593 | my ($self, $function, %arg) = @_; |
623 | my ($self, $function, %arg) = @_; |
… | |
… | |
867 | are queued and the jobs are slow, they will all run concurrently. The |
897 | are queued and the jobs are slow, they will all run concurrently. The |
868 | child must implement some queueing/limiting mechanism if this causes |
898 | child must implement some queueing/limiting mechanism if this causes |
869 | problems. Alternatively, the parent could limit the amount of rpc calls |
899 | problems. Alternatively, the parent could limit the amount of rpc calls |
870 | that are outstanding. |
900 | that are outstanding. |
871 | |
901 | |
872 | Blocking use of condvars is not supported. |
902 | Blocking use of condvars is not supported (in the main thread, outside of |
|
|
903 | e.g. L<Coro> threads). |
873 | |
904 | |
874 | Using event-based modules such as L<IO::AIO>, L<Gtk2>, L<Tk> and so on is |
905 | Using event-based modules such as L<IO::AIO>, L<Gtk2>, L<Tk> and so on is |
875 | easy. |
906 | easy. |
876 | |
907 | |
877 | =back |
908 | =back |
… | |
… | |
943 | gory details. |
974 | gory details. |
944 | |
975 | |
945 | =head1 EXCEPTIONS |
976 | =head1 EXCEPTIONS |
946 | |
977 | |
947 | There are no provisions whatsoever for catching exceptions at this time - |
978 | There are no provisions whatsoever for catching exceptions at this time - |
948 | in the child, exeptions might kill the process, causing calls to be lost |
979 | in the child, exceptions might kill the process, causing calls to be lost |
949 | and the parent encountering a fatal error. In the parent, exceptions in |
980 | and the parent encountering a fatal error. In the parent, exceptions in |
950 | the result callback will not be caught and cause undefined behaviour. |
981 | the result callback will not be caught and cause undefined behaviour. |
951 | |
982 | |
952 | =head1 SEE ALSO |
983 | =head1 SEE ALSO |
953 | |
984 | |