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Revision 1.26 by root, Thu Oct 4 12:50:35 2007 UTC vs.
Revision 1.31 by root, Thu May 29 03:35:03 2008 UTC

24 $req->cancel; # cancel request if still in queue 24 $req->cancel; # cancel request if still in queue
25 25
26 my $grp = aio_group sub { print "all stats done\n" }; 26 my $grp = aio_group sub { print "all stats done\n" };
27 add $grp aio_stat "..." for ...; 27 add $grp aio_stat "..." for ...;
28 28
29 # AnyEvent integration (EV, Event, Glib, Tk, POE, urxvt, pureperl...)
30 use AnyEvent::AIO;
31
29 # AnyEvent integration 32 # EV integration
30 open my $fh, "<&=" . IO::AIO::poll_fileno or die "$!"; 33 my $w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb;
31 my $w = AnyEvent->io (fh => $fh, poll => 'r', cb => sub { IO::AIO::poll_cb });
32 34
33 # Event integration 35 # Event integration
34 Event->io (fd => IO::AIO::poll_fileno, 36 Event->io (fd => IO::AIO::poll_fileno,
35 poll => 'r', 37 poll => 'r',
36 cb => \&IO::AIO::poll_cb); 38 cb => \&IO::AIO::poll_cb);
260 262
261 aio_close $fh, $callback->($status) 263 aio_close $fh, $callback->($status)
262 Asynchronously close a file and call the callback with the result 264 Asynchronously close a file and call the callback with the result
263 code. 265 code.
264 266
265 Unlike the other functions operating on files, this function uses 267 Unfortunately, you can't do this to perl. Perl *insists* very
266 the PerlIO layer to close the filehandle. The reason is that the 268 strongly on closing the file descriptor associated with the
267 PerlIO API insists on closing the underlying fd itself, no matter 269 filehandle itself.
268 what, and doesn't allow modifications to the fd. Unfortunately, it
269 is not clear that you can call PerlIO from different threads
270 (actually, its quite clear that this won't work in some cases), so
271 while it likely works perfectly with simple file handles (such as
272 the ones created by "aio_open") it might fail in interesting ways
273 for others.
274 270
275 Having said that, aio_close tries to clean up the filehandle as much 271 Therefore, "aio_close" will not close the filehandle - instead it
276 as possible before handing it to an io thread, and generally does 272 will use dup2 to overwrite the file descriptor with the write-end of
277 work. 273 a pipe (the pipe fd will be created on demand and will be cached).
274
275 Or in other words: the file descriptor will be closed, but it will
276 not be free for reuse until the perl filehandle is closed.
278 277
279 aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval) 278 aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
280 aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval) 279 aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
281 Reads or writes $length bytes from the specified $fh and $offset 280 Reads or writes $length bytes from the specified $fh and $offset
282 into the scalar given by $data and offset $dataoffset and calls the 281 into the scalar given by $data and offset $dataoffset and calls the
529 Delete a directory tree starting (and including) $path, return the 528 Delete a directory tree starting (and including) $path, return the
530 status of the final "rmdir" only. This is a composite request that 529 status of the final "rmdir" only. This is a composite request that
531 uses "aio_scandir" to recurse into and rmdir directories, and unlink 530 uses "aio_scandir" to recurse into and rmdir directories, and unlink
532 everything else. 531 everything else.
533 532
533 aio_sync $callback->($status)
534 Asynchronously call sync and call the callback when finished.
535
534 aio_fsync $fh, $callback->($status) 536 aio_fsync $fh, $callback->($status)
535 Asynchronously call fsync on the given filehandle and call the 537 Asynchronously call fsync on the given filehandle and call the
536 callback with the fsync result code. 538 callback with the fsync result code.
537 539
538 aio_fdatasync $fh, $callback->($status) 540 aio_fdatasync $fh, $callback->($status)
539 Asynchronously call fdatasync on the given filehandle and call the 541 Asynchronously call fdatasync on the given filehandle and call the
540 callback with the fdatasync result code. 542 callback with the fdatasync result code.
541 543
542 If this call isn't available because your OS lacks it or it couldn't 544 If this call isn't available because your OS lacks it or it couldn't
543 be detected, it will be emulated by calling "fsync" instead. 545 be detected, it will be emulated by calling "fsync" instead.
546
547 aio_pathsync $path, $callback->($status)
548 This request tries to open, fsync and close the given path. This is
549 a composite request intended tosync directories after directory
550 operations (E.g. rename). This might not work on all operating
551 systems or have any specific effect, but usually it makes sure that
552 directory changes get written to disc. It works for anything that
553 can be opened for read-only, not just directories.
554
555 Passes 0 when everything went ok, and -1 on error.
544 556
545 aio_group $callback->(...) 557 aio_group $callback->(...)
546 This is a very special aio request: Instead of doing something, it 558 This is a very special aio request: Instead of doing something, it
547 is a container for other aio requests, which is useful if you want 559 is a container for other aio requests, which is useful if you want
548 to bundle many requests into a single, composite, request with a 560 to bundle many requests into a single, composite, request with a
630 }; 642 };
631 643
632 This makes it very easy to create composite requests (see the source of 644 This makes it very easy to create composite requests (see the source of
633 "aio_move" for an application) that work and feel like simple requests. 645 "aio_move" for an application) that work and feel like simple requests.
634 646
635 * The IO::AIO::GRP objects will be cleaned up during calls to 647 * The IO::AIO::GRP objects will be cleaned up during calls to
636 "IO::AIO::poll_cb", just like any other request. 648 "IO::AIO::poll_cb", just like any other request.
649
637 * They can be canceled like any other request. Canceling will cancel not 650 * They can be canceled like any other request. Canceling will cancel
638 only the request itself, but also all requests it contains. 651 not only the request itself, but also all requests it contains.
652
639 * They can also can also be added to other IO::AIO::GRP objects. 653 * They can also can also be added to other IO::AIO::GRP objects.
654
640 * You must not add requests to a group from within the group callback 655 * You must not add requests to a group from within the group callback
641 (or any later time). 656 (or any later time).
642 657
643 Their lifetime, simplified, looks like this: when they are empty, they 658 Their lifetime, simplified, looks like this: when they are empty, they
644 will finish very quickly. If they contain only requests that are in the 659 will finish very quickly. If they contain only requests that are in the
645 "done" state, they will also finish. Otherwise they will continue to 660 "done" state, they will also finish. Otherwise they will continue to
646 exist. 661 exist.
663 request itself. Useful when you queued a lot of events but got a 678 request itself. Useful when you queued a lot of events but got a
664 result early. 679 result early.
665 680
666 $grp->result (...) 681 $grp->result (...)
667 Set the result value(s) that will be passed to the group callback 682 Set the result value(s) that will be passed to the group callback
668 when all subrequests have finished and set thre groups errno to the 683 when all subrequests have finished and set the groups errno to the
669 current value of errno (just like calling "errno" without an error 684 current value of errno (just like calling "errno" without an error
670 number). By default, no argument will be passed and errno is zero. 685 number). By default, no argument will be passed and errno is zero.
671 686
672 $grp->errno ([$errno]) 687 $grp->errno ([$errno])
673 Sets the group errno value to $errno, or the current value of errno 688 Sets the group errno value to $errno, or the current value of errno
732 747
733 See "poll_cb" for an example. 748 See "poll_cb" for an example.
734 749
735 IO::AIO::poll_cb 750 IO::AIO::poll_cb
736 Process some outstanding events on the result pipe. You have to call 751 Process some outstanding events on the result pipe. You have to call
737 this regularly. Returns the number of events processed. Returns 752 this regularly. Returns 0 if all events could be processed, or -1 if
738 immediately when no events are outstanding. The amount of events 753 it returned earlier for whatever reason. Returns immediately when no
754 events are outstanding. The amount of events processed depends on
739 processed depends on the settings of "IO::AIO::max_poll_req" and 755 the settings of "IO::AIO::max_poll_req" and
740 "IO::AIO::max_poll_time". 756 "IO::AIO::max_poll_time".
741 757
742 If not all requests were processed for whatever reason, the 758 If not all requests were processed for whatever reason, the
743 filehandle will still be ready when "poll_cb" returns. 759 filehandle will still be ready when "poll_cb" returns, so normally
760 you don't have to do anything special to have it called later.
744 761
745 Example: Install an Event watcher that automatically calls 762 Example: Install an Event watcher that automatically calls
746 IO::AIO::poll_cb with high priority: 763 IO::AIO::poll_cb with high priority:
747 764
748 Event->io (fd => IO::AIO::poll_fileno, 765 Event->io (fd => IO::AIO::poll_fileno,
854 871
855 The default is probably ok in most situations, especially if thread 872 The default is probably ok in most situations, especially if thread
856 creation is fast. If thread creation is very slow on your system you 873 creation is fast. If thread creation is very slow on your system you
857 might want to use larger values. 874 might want to use larger values.
858 875
859 $oldmaxreqs = IO::AIO::max_outstanding $maxreqs 876 IO::AIO::max_outstanding $maxreqs
860 This is a very bad function to use in interactive programs because 877 This is a very bad function to use in interactive programs because
861 it blocks, and a bad way to reduce concurrency because it is 878 it blocks, and a bad way to reduce concurrency because it is
862 inexact: Better use an "aio_group" together with a feed callback. 879 inexact: Better use an "aio_group" together with a feed callback.
863 880
864 Sets the maximum number of outstanding requests to $nreqs. If you do 881 Sets the maximum number of outstanding requests to $nreqs. If you do
868 885
869 The default value is very large, so there is no practical limit on 886 The default value is very large, so there is no practical limit on
870 the number of outstanding requests. 887 the number of outstanding requests.
871 888
872 You can still queue as many requests as you want. Therefore, 889 You can still queue as many requests as you want. Therefore,
873 "max_oustsanding" is mainly useful in simple scripts (with low 890 "max_outstanding" is mainly useful in simple scripts (with low
874 values) or as a stop gap to shield against fatal memory overflow 891 values) or as a stop gap to shield against fatal memory overflow
875 (with large values). 892 (with large values).
876 893
877 STATISTICAL INFORMATION 894 STATISTICAL INFORMATION
878 IO::AIO::nreqs 895 IO::AIO::nreqs
928 945
929KNOWN BUGS 946KNOWN BUGS
930 Known bugs will be fixed in the next release. 947 Known bugs will be fixed in the next release.
931 948
932SEE ALSO 949SEE ALSO
933 Coro::AIO. 950 AnyEvent::AIO for easy integration into event loops, Coro::AIO for a
951 more natural syntax.
934 952
935AUTHOR 953AUTHOR
936 Marc Lehmann <schmorp@schmorp.de> 954 Marc Lehmann <schmorp@schmorp.de>
937 http://home.schmorp.de/ 955 http://home.schmorp.de/
938 956

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