… | |
… | |
18 | }; |
18 | }; |
19 | |
19 | |
20 | # version 2+ has request and group objects |
20 | # version 2+ has request and group objects |
21 | use IO::AIO 2; |
21 | use IO::AIO 2; |
22 | |
22 | |
|
|
23 | aioreq_pri 4; # give next request a very high priority |
23 | my $req = aio_unlink "/tmp/file", sub { }; |
24 | my $req = aio_unlink "/tmp/file", sub { }; |
24 | $req->cancel; # cancel request if still in queue |
25 | $req->cancel; # cancel request if still in queue |
25 | |
26 | |
26 | my $grp = aio_group sub { print "all stats done\n" }; |
27 | my $grp = aio_group sub { print "all stats done\n" }; |
27 | add $grp aio_stat "..." for ...; |
28 | add $grp aio_stat "..." for ...; |
… | |
… | |
51 | |
52 | |
52 | This module implements asynchronous I/O using whatever means your |
53 | This module implements asynchronous I/O using whatever means your |
53 | operating system supports. |
54 | operating system supports. |
54 | |
55 | |
55 | Currently, a number of threads are started that execute your read/writes |
56 | Currently, a number of threads are started that execute your read/writes |
56 | and signal their completion. You don't need thread support in your libc or |
57 | and signal their completion. You don't need thread support in perl, and |
57 | perl, and the threads created by this module will not be visible to the |
58 | the threads created by this module will not be visible to perl. In the |
58 | pthreads library. In the future, this module might make use of the native |
59 | future, this module might make use of the native aio functions available |
59 | aio functions available on many operating systems. However, they are often |
60 | on many operating systems. However, they are often not well-supported |
60 | not well-supported (Linux doesn't allow them on normal files currently, |
61 | (Linux doesn't allow them on normal files currently, for example), |
61 | for example), and they would only support aio_read and aio_write, so the |
62 | and they would only support aio_read and aio_write, so the remaining |
62 | remaining functionality would have to be implemented using threads anyway. |
63 | functionality would have to be implemented using threads anyway. |
63 | |
64 | |
64 | Although the module will work with in the presence of other threads, it is |
65 | Although the module will work with in the presence of other threads, |
65 | currently not reentrant, so use appropriate locking yourself, always call |
66 | it is currently not reentrant in any way, so use appropriate locking |
66 | C<poll_cb> from within the same thread, or never call C<poll_cb> (or other |
67 | yourself, always call C<poll_cb> from within the same thread, or never |
67 | C<aio_> functions) recursively. |
68 | call C<poll_cb> (or other C<aio_> functions) recursively. |
68 | |
69 | |
69 | =cut |
70 | =cut |
70 | |
71 | |
71 | package IO::AIO; |
72 | package IO::AIO; |
72 | |
73 | |
… | |
… | |
76 | use base 'Exporter'; |
77 | use base 'Exporter'; |
77 | |
78 | |
78 | BEGIN { |
79 | BEGIN { |
79 | our $VERSION = '2.0'; |
80 | our $VERSION = '2.0'; |
80 | |
81 | |
81 | our @EXPORT = qw(aio_sendfile aio_read aio_write aio_open aio_close aio_stat |
82 | our @AIO_REQ = qw(aio_sendfile aio_read aio_write aio_open aio_close aio_stat |
82 | aio_lstat aio_unlink aio_rmdir aio_readdir aio_scandir aio_symlink |
83 | aio_lstat aio_unlink aio_rmdir aio_readdir aio_scandir aio_symlink |
83 | aio_fsync aio_fdatasync aio_readahead aio_rename aio_link aio_move |
84 | aio_fsync aio_fdatasync aio_readahead aio_rename aio_link aio_move |
84 | aio_group); |
85 | aio_group aio_nop); |
85 | our @EXPORT_OK = qw(poll_fileno poll_cb min_parallel max_parallel max_outstanding nreqs); |
86 | our @EXPORT = (@AIO_REQ, qw(aioreq_pri)); |
|
|
87 | our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush |
|
|
88 | min_parallel max_parallel max_outstanding nreqs); |
86 | |
89 | |
87 | @IO::AIO::GRP::ISA = 'IO::AIO::REQ'; |
90 | @IO::AIO::GRP::ISA = 'IO::AIO::REQ'; |
88 | |
91 | |
89 | require XSLoader; |
92 | require XSLoader; |
90 | XSLoader::load ("IO::AIO", $VERSION); |
93 | XSLoader::load ("IO::AIO", $VERSION); |
… | |
… | |
120 | your pathnames to the locale (or other) encoding in effect in the user |
123 | your pathnames to the locale (or other) encoding in effect in the user |
121 | environment, d) use Glib::filename_from_unicode on unicode filenames or e) |
124 | environment, d) use Glib::filename_from_unicode on unicode filenames or e) |
122 | use something else. |
125 | use something else. |
123 | |
126 | |
124 | =over 4 |
127 | =over 4 |
|
|
128 | |
|
|
129 | =item aioreq_pri $pri |
|
|
130 | |
|
|
131 | Sets the priority for the next aio request. The default priority |
|
|
132 | is C<0>, the minimum and maximum priorities are C<-4> and C<4>, |
|
|
133 | respectively. Requests with higher priority will be serviced first. |
|
|
134 | |
|
|
135 | The priority will be reset to C<0> after each call to one of the C<aio_> |
|
|
136 | functions. |
125 | |
137 | |
126 | =item aio_open $pathname, $flags, $mode, $callback->($fh) |
138 | =item aio_open $pathname, $flags, $mode, $callback->($fh) |
127 | |
139 | |
128 | Asynchronously open or create a file and call the callback with a newly |
140 | Asynchronously open or create a file and call the callback with a newly |
129 | created filehandle for the file. |
141 | created filehandle for the file. |
… | |
… | |
533 | add $grp |
545 | add $grp |
534 | (aio_stat ...), |
546 | (aio_stat ...), |
535 | (aio_stat ...), |
547 | (aio_stat ...), |
536 | ...; |
548 | ...; |
537 | |
549 | |
|
|
550 | =item aio_nop $callback->() |
|
|
551 | |
|
|
552 | This is a special request - it does nothing in itself and is only used for |
|
|
553 | side effects, such as when you want to add a dummy request to a group so |
|
|
554 | that finishing the requests in the group depends on executing the given |
|
|
555 | code. |
|
|
556 | |
|
|
557 | While this request does nothing, it still goes through the execution |
|
|
558 | phase and still requires a worker thread. Thus, the callback will not |
|
|
559 | be executed immediately but only after other requests in the queue have |
|
|
560 | entered their execution phase. This can be used to measure request |
|
|
561 | latency. |
|
|
562 | |
538 | =item IO::AIO::aio_sleep $fractional_seconds, $callback->() *NOT EXPORTED* |
563 | =item IO::AIO::aio_sleep $fractional_seconds, $callback->() *NOT EXPORTED* |
539 | |
564 | |
540 | Mainly used for debugging and benchmarking, this aio request puts one of |
565 | Mainly used for debugging and benchmarking, this aio request puts one of |
541 | the request workers to sleep for the given time. |
566 | the request workers to sleep for the given time. |
542 | |
567 | |
… | |
… | |
560 | callback) and B<done> (request has reached the end of its lifetime and |
585 | callback) and B<done> (request has reached the end of its lifetime and |
561 | holds no resources anymore). |
586 | holds no resources anymore). |
562 | |
587 | |
563 | =over 4 |
588 | =over 4 |
564 | |
589 | |
565 | =item $req->cancel |
590 | =item cancel $req |
566 | |
591 | |
567 | Cancels the request, if possible. Has the effect of skipping execution |
592 | Cancels the request, if possible. Has the effect of skipping execution |
568 | when entering the B<execute> state and skipping calling the callback when |
593 | when entering the B<execute> state and skipping calling the callback when |
569 | entering the the B<result> state, but will leave the request otherwise |
594 | entering the the B<result> state, but will leave the request otherwise |
570 | untouched. That means that requests that currently execute will not be |
595 | untouched. That means that requests that currently execute will not be |
571 | stopped and resources held by the request will not be freed prematurely. |
596 | stopped and resources held by the request will not be freed prematurely. |
572 | |
597 | |
|
|
598 | =item cb $req $callback->(...) |
|
|
599 | |
|
|
600 | Replace (or simply set) the callback registered to the request. |
|
|
601 | |
573 | =back |
602 | =back |
574 | |
603 | |
575 | =head2 IO::AIO::GRP CLASS |
604 | =head2 IO::AIO::GRP CLASS |
576 | |
605 | |
577 | This class is a subclass of L<IO::AIO::REQ>, so all its methods apply to |
606 | This class is a subclass of L<IO::AIO::REQ>, so all its methods apply to |
… | |
… | |
603 | }; |
632 | }; |
604 | |
633 | |
605 | This makes it very easy to create composite requests (see the source of |
634 | This makes it very easy to create composite requests (see the source of |
606 | C<aio_move> for an application) that work and feel like simple requests. |
635 | C<aio_move> for an application) that work and feel like simple requests. |
607 | |
636 | |
|
|
637 | =over 4 |
|
|
638 | |
608 | The IO::AIO::GRP objects will be cleaned up during calls to |
639 | =item * The IO::AIO::GRP objects will be cleaned up during calls to |
609 | C<IO::AIO::poll_cb>, just like any other request. |
640 | C<IO::AIO::poll_cb>, just like any other request. |
610 | |
641 | |
611 | They can be canceled like any other request. Canceling will cancel not |
642 | =item * They can be canceled like any other request. Canceling will cancel not |
612 | only the request itself, but also all requests it contains. |
643 | only the request itself, but also all requests it contains. |
613 | |
644 | |
614 | They can also can also be added to other IO::AIO::GRP objects. |
645 | =item * They can also can also be added to other IO::AIO::GRP objects. |
615 | |
646 | |
616 | You must not add requests to a group from within the group callback (or |
647 | =item * You must not add requests to a group from within the group callback (or |
617 | any later time). |
648 | any later time). |
|
|
649 | |
|
|
650 | =item * This does not harmonise well with C<max_outstanding>, so best do |
|
|
651 | not combine C<aio_group> with it. Groups and feeders are recommended for |
|
|
652 | this kind of concurrency-limiting. |
|
|
653 | |
|
|
654 | =back |
618 | |
655 | |
619 | Their lifetime, simplified, looks like this: when they are empty, they |
656 | Their lifetime, simplified, looks like this: when they are empty, they |
620 | will finish very quickly. If they contain only requests that are in the |
657 | will finish very quickly. If they contain only requests that are in the |
621 | C<done> state, they will also finish. Otherwise they will continue to |
658 | C<done> state, they will also finish. Otherwise they will continue to |
622 | exist. |
659 | exist. |
… | |
… | |
626 | group. And only when all those requests have finished will the the group |
663 | group. And only when all those requests have finished will the the group |
627 | itself finish. |
664 | itself finish. |
628 | |
665 | |
629 | =over 4 |
666 | =over 4 |
630 | |
667 | |
|
|
668 | =item add $grp ... |
|
|
669 | |
631 | =item $grp->add (...) |
670 | =item $grp->add (...) |
632 | |
|
|
633 | =item add $grp ... |
|
|
634 | |
671 | |
635 | Add one or more requests to the group. Any type of L<IO::AIO::REQ> can |
672 | Add one or more requests to the group. Any type of L<IO::AIO::REQ> can |
636 | be added, including other groups, as long as you do not create circular |
673 | be added, including other groups, as long as you do not create circular |
637 | dependencies. |
674 | dependencies. |
638 | |
675 | |
… | |
… | |
641 | =item $grp->result (...) |
678 | =item $grp->result (...) |
642 | |
679 | |
643 | Set the result value(s) that will be passed to the group callback when all |
680 | Set the result value(s) that will be passed to the group callback when all |
644 | subrequests have finished. By default, no argument will be passed. |
681 | subrequests have finished. By default, no argument will be passed. |
645 | |
682 | |
646 | =item $grp->set_feeder ($callback->($grp)) |
683 | =item feed $grp $callback->($grp) |
647 | |
684 | |
648 | [VERY EXPERIMENTAL] |
685 | [VERY EXPERIMENTAL] |
649 | |
686 | |
650 | Sets a feeder/generator on this group: every group can have an attached |
687 | Sets a feeder/generator on this group: every group can have an attached |
651 | generator that generates requests if idle. The idea behind this is that, |
688 | generator that generates requests if idle. The idea behind this is that, |
… | |
… | |
654 | example, C<aio_scandir> might generate hundreds of thousands C<aio_stat> |
691 | example, C<aio_scandir> might generate hundreds of thousands C<aio_stat> |
655 | requests, delaying any later requests for a long time. |
692 | requests, delaying any later requests for a long time. |
656 | |
693 | |
657 | To avoid this, and allow incremental generation of requests, you can |
694 | To avoid this, and allow incremental generation of requests, you can |
658 | instead a group and set a feeder on it that generates those requests. The |
695 | instead a group and set a feeder on it that generates those requests. The |
659 | feeder will be called whenever there are few enough (see C<feeder_limit>, |
696 | feed callback will be called whenever there are few enough (see C<limit>, |
660 | below) requests active in the group itself and is expected to queue more |
697 | below) requests active in the group itself and is expected to queue more |
661 | requests. |
698 | requests. |
662 | |
699 | |
663 | The feeder can queue as many requests as it likes (i.e. C<add> does not |
700 | The feed callback can queue as many requests as it likes (i.e. C<add> does |
664 | impose any limits). |
701 | not impose any limits). |
665 | |
702 | |
666 | If the feeder does not queue more requests when called, it will be |
703 | If the feed does not queue more requests when called, it will be |
667 | automatically removed from the group. |
704 | automatically removed from the group. |
668 | |
705 | |
669 | If the feeder limit is C<0>, it will be set to C<2> automatically. |
706 | If the feed limit is C<0>, it will be set to C<2> automatically. |
670 | |
707 | |
671 | Example: |
708 | Example: |
672 | |
709 | |
673 | # stat all files in @files, but only ever use four aio requests concurrently: |
710 | # stat all files in @files, but only ever use four aio requests concurrently: |
674 | |
711 | |
675 | my $grp = aio_group sub { print "finished\n" }; |
712 | my $grp = aio_group sub { print "finished\n" }; |
676 | $grp->feeder_limit (4); |
713 | limit $grp 4; |
677 | $grp->set_feeder (sub { |
714 | feed $grp sub { |
678 | my $file = pop @files |
715 | my $file = pop @files |
679 | or return; |
716 | or return; |
680 | |
717 | |
681 | add $grp aio_stat $file, sub { ... }; |
718 | add $grp aio_stat $file, sub { ... }; |
682 | }); |
719 | }; |
683 | |
720 | |
684 | =item $grp->feeder_limit ($num) |
721 | =item limit $grp $num |
685 | |
722 | |
686 | Sets the feeder limit for the group: The feeder will be called whenever |
723 | Sets the feeder limit for the group: The feeder will be called whenever |
687 | the group contains less than this many requests. |
724 | the group contains less than this many requests. |
688 | |
725 | |
689 | Setting the limit to C<0> will pause the feeding process. |
726 | Setting the limit to C<0> will pause the feeding process. |
… | |
… | |
784 | |
821 | |
785 | Under normal circumstances you don't need to call this function. |
822 | Under normal circumstances you don't need to call this function. |
786 | |
823 | |
787 | =item $oldnreqs = IO::AIO::max_outstanding $nreqs |
824 | =item $oldnreqs = IO::AIO::max_outstanding $nreqs |
788 | |
825 | |
|
|
826 | [DEPRECATED] |
|
|
827 | |
789 | Sets the maximum number of outstanding requests to C<$nreqs>. If you |
828 | Sets the maximum number of outstanding requests to C<$nreqs>. If you |
790 | try to queue up more than this number of requests, the caller will block until |
829 | try to queue up more than this number of requests, the caller will block until |
791 | some requests have been handled. |
830 | some requests have been handled. |
792 | |
831 | |
793 | The default is very large, so normally there is no practical limit. If you |
832 | The default is very large, so normally there is no practical limit. If you |
794 | queue up many requests in a loop it often improves speed if you set |
833 | queue up many requests in a loop it often improves speed if you set |
795 | this to a relatively low number, such as C<100>. |
834 | this to a relatively low number, such as C<100>. |
|
|
835 | |
|
|
836 | This function does not work well together with C<aio_group>'s, and their |
|
|
837 | feeder interface is better suited to limiting concurrency, so do not use |
|
|
838 | this function. |
796 | |
839 | |
797 | Under normal circumstances you don't need to call this function. |
840 | Under normal circumstances you don't need to call this function. |
798 | |
841 | |
799 | =back |
842 | =back |
800 | |
843 | |
… | |
… | |
853 | Each thread needs a stack area which is usually around 16k, sometimes much |
896 | Each thread needs a stack area which is usually around 16k, sometimes much |
854 | larger, depending on the OS. |
897 | larger, depending on the OS. |
855 | |
898 | |
856 | =head1 SEE ALSO |
899 | =head1 SEE ALSO |
857 | |
900 | |
858 | L<Coro>, L<Linux::AIO> (obsolete). |
901 | L<Coro::AIO>. |
859 | |
902 | |
860 | =head1 AUTHOR |
903 | =head1 AUTHOR |
861 | |
904 | |
862 | Marc Lehmann <schmorp@schmorp.de> |
905 | Marc Lehmann <schmorp@schmorp.de> |
863 | http://home.schmorp.de/ |
906 | http://home.schmorp.de/ |