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Revision 1.64 by root, Mon Oct 23 00:50:10 2006 UTC vs.
Revision 1.68 by root, Tue Oct 24 03:17:39 2006 UTC

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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 ...;
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51 52
52This module implements asynchronous I/O using whatever means your 53This module implements asynchronous I/O using whatever means your
53operating system supports. 54operating system supports.
54 55
55Currently, a number of threads are started that execute your read/writes 56Currently, a number of threads are started that execute your read/writes
56and signal their completion. You don't need thread support in your libc or 57and signal their completion. You don't need thread support in perl, and
57perl, and the threads created by this module will not be visible to the 58the threads created by this module will not be visible to perl. In the
58pthreads library. In the future, this module might make use of the native 59future, this module might make use of the native aio functions available
59aio functions available on many operating systems. However, they are often 60on many operating systems. However, they are often not well-supported
60not well-supported (Linux doesn't allow them on normal files currently, 61(Linux doesn't allow them on normal files currently, for example),
61for example), and they would only support aio_read and aio_write, so the 62and they would only support aio_read and aio_write, so the remaining
62remaining functionality would have to be implemented using threads anyway. 63functionality would have to be implemented using threads anyway.
63 64
64Although the module will work with in the presence of other threads, it is 65Although the module will work with in the presence of other threads,
65currently not reentrant, so use appropriate locking yourself, always call 66it is currently not reentrant in any way, so use appropriate locking
66C<poll_cb> from within the same thread, or never call C<poll_cb> (or other 67yourself, always call C<poll_cb> from within the same thread, or never
67C<aio_> functions) recursively. 68call C<poll_cb> (or other C<aio_> functions) recursively.
68 69
69=cut 70=cut
70 71
71package IO::AIO; 72package IO::AIO;
72 73
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76use base 'Exporter'; 77use base 'Exporter';
77 78
78BEGIN { 79BEGIN {
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 aio_nop); 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);
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120your pathnames to the locale (or other) encoding in effect in the user 123your pathnames to the locale (or other) encoding in effect in the user
121environment, d) use Glib::filename_from_unicode on unicode filenames or e) 124environment, d) use Glib::filename_from_unicode on unicode filenames or e)
122use something else. 125use something else.
123 126
124=over 4 127=over 4
128
129=item aioreq_pri $pri
130
131Sets the priority for the next aio request. The default priority
132is C<0>, the minimum and maximum priorities are C<-4> and C<4>,
133respectively. Requests with higher priority will be serviced first.
134
135The priority will be reset to C<0> after each call to one of the C<aio_>
136functions.
125 137
126=item aio_open $pathname, $flags, $mode, $callback->($fh) 138=item aio_open $pathname, $flags, $mode, $callback->($fh)
127 139
128Asynchronously open or create a file and call the callback with a newly 140Asynchronously open or create a file and call the callback with a newly
129created filehandle for the file. 141created filehandle for the file.
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573callback) and B<done> (request has reached the end of its lifetime and 585callback) and B<done> (request has reached the end of its lifetime and
574holds no resources anymore). 586holds no resources anymore).
575 587
576=over 4 588=over 4
577 589
578=item $req->cancel 590=item cancel $req
579 591
580Cancels the request, if possible. Has the effect of skipping execution 592Cancels the request, if possible. Has the effect of skipping execution
581when entering the B<execute> state and skipping calling the callback when 593when entering the B<execute> state and skipping calling the callback when
582entering the the B<result> state, but will leave the request otherwise 594entering the the B<result> state, but will leave the request otherwise
583untouched. That means that requests that currently execute will not be 595untouched. That means that requests that currently execute will not be
584stopped and resources held by the request will not be freed prematurely. 596stopped and resources held by the request will not be freed prematurely.
585 597
598=item cb $req $callback->(...)
599
600Replace (or simply set) the callback registered to the request.
601
586=back 602=back
587 603
588=head2 IO::AIO::GRP CLASS 604=head2 IO::AIO::GRP CLASS
589 605
590This class is a subclass of L<IO::AIO::REQ>, so all its methods apply to 606This class is a subclass of L<IO::AIO::REQ>, so all its methods apply to
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647group. And only when all those requests have finished will the the group 663group. And only when all those requests have finished will the the group
648itself finish. 664itself finish.
649 665
650=over 4 666=over 4
651 667
668=item add $grp ...
669
652=item $grp->add (...) 670=item $grp->add (...)
653
654=item add $grp ...
655 671
656Add one or more requests to the group. Any type of L<IO::AIO::REQ> can 672Add one or more requests to the group. Any type of L<IO::AIO::REQ> can
657be added, including other groups, as long as you do not create circular 673be added, including other groups, as long as you do not create circular
658dependencies. 674dependencies.
659 675
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662=item $grp->result (...) 678=item $grp->result (...)
663 679
664Set the result value(s) that will be passed to the group callback when all 680Set the result value(s) that will be passed to the group callback when all
665subrequests have finished. By default, no argument will be passed. 681subrequests have finished. By default, no argument will be passed.
666 682
667=item $grp->set_feeder ($callback->($grp)) 683=item feed $grp $callback->($grp)
668 684
669[VERY EXPERIMENTAL] 685[VERY EXPERIMENTAL]
670 686
671Sets a feeder/generator on this group: every group can have an attached 687Sets a feeder/generator on this group: every group can have an attached
672generator that generates requests if idle. The idea behind this is that, 688generator that generates requests if idle. The idea behind this is that,
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675example, C<aio_scandir> might generate hundreds of thousands C<aio_stat> 691example, C<aio_scandir> might generate hundreds of thousands C<aio_stat>
676requests, delaying any later requests for a long time. 692requests, delaying any later requests for a long time.
677 693
678To avoid this, and allow incremental generation of requests, you can 694To avoid this, and allow incremental generation of requests, you can
679instead a group and set a feeder on it that generates those requests. The 695instead a group and set a feeder on it that generates those requests. The
680feeder will be called whenever there are few enough (see C<feeder_limit>, 696feed callback will be called whenever there are few enough (see C<limit>,
681below) requests active in the group itself and is expected to queue more 697below) requests active in the group itself and is expected to queue more
682requests. 698requests.
683 699
684The feeder can queue as many requests as it likes (i.e. C<add> does not 700The feed callback can queue as many requests as it likes (i.e. C<add> does
685impose any limits). 701not impose any limits).
686 702
687If the feeder does not queue more requests when called, it will be 703If the feed does not queue more requests when called, it will be
688automatically removed from the group. 704automatically removed from the group.
689 705
690If the feeder limit is C<0>, it will be set to C<2> automatically. 706If the feed limit is C<0>, it will be set to C<2> automatically.
691 707
692Example: 708Example:
693 709
694 # 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:
695 711
696 my $grp = aio_group sub { print "finished\n" }; 712 my $grp = aio_group sub { print "finished\n" };
697 $grp->feeder_limit (4); 713 limit $grp 4;
698 $grp->set_feeder (sub { 714 feed $grp sub {
699 my $file = pop @files 715 my $file = pop @files
700 or return; 716 or return;
701 717
702 add $grp aio_stat $file, sub { ... }; 718 add $grp aio_stat $file, sub { ... };
703 }); 719 };
704 720
705=item $grp->feeder_limit ($num) 721=item limit $grp $num
706 722
707Sets the feeder limit for the group: The feeder will be called whenever 723Sets the feeder limit for the group: The feeder will be called whenever
708the group contains less than this many requests. 724the group contains less than this many requests.
709 725
710Setting the limit to C<0> will pause the feeding process. 726Setting the limit to C<0> will pause the feeding process.
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880Each thread needs a stack area which is usually around 16k, sometimes much 896Each thread needs a stack area which is usually around 16k, sometimes much
881larger, depending on the OS. 897larger, depending on the OS.
882 898
883=head1 SEE ALSO 899=head1 SEE ALSO
884 900
885L<Coro>, L<Linux::AIO> (obsolete). 901L<Coro::AIO>.
886 902
887=head1 AUTHOR 903=head1 AUTHOR
888 904
889 Marc Lehmann <schmorp@schmorp.de> 905 Marc Lehmann <schmorp@schmorp.de>
890 http://home.schmorp.de/ 906 http://home.schmorp.de/

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