ViewVC Help
View File | Revision Log | Show Annotations | Download File
/cvs/IO-AIO/README
(Generate patch)

Comparing IO-AIO/README (file contents):
Revision 1.25 by root, Mon Sep 24 19:28:50 2007 UTC vs.
Revision 1.30 by root, Sat May 10 22:58:16 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);
258 } 260 }
259 }; 261 };
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. *WARNING:* although accepted, you should not pass in a perl 265 code.
264 filehandle here, as perl will likely close the file descriptor
265 another time when the filehandle is destroyed. Normally, you can
266 safely call perls "close" or just let filehandles go out of scope.
267 266
268 This is supposed to be a bug in the API, so that might change. It's 267 Unfortunately, you can't do this to perl. Perl *insists* very
269 therefore best to avoid this function. 268 strongly on closing the file descriptor associated with the
269 filehandle itself.
270
271 Therefore, "aio_close" will not close the filehandle - instead it
272 will use dup2 to overwrite the file descriptor with the write-end of
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.
270 277
271 aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval) 278 aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
272 aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval) 279 aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
273 Reads or writes $length bytes from the specified $fh and $offset 280 Reads or writes $length bytes from the specified $fh and $offset
274 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
521 Delete a directory tree starting (and including) $path, return the 528 Delete a directory tree starting (and including) $path, return the
522 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
523 uses "aio_scandir" to recurse into and rmdir directories, and unlink 530 uses "aio_scandir" to recurse into and rmdir directories, and unlink
524 everything else. 531 everything else.
525 532
533 aio_sync $callback->($status)
534 Asynchronously call sync and call the callback when finished.
535
526 aio_fsync $fh, $callback->($status) 536 aio_fsync $fh, $callback->($status)
527 Asynchronously call fsync on the given filehandle and call the 537 Asynchronously call fsync on the given filehandle and call the
528 callback with the fsync result code. 538 callback with the fsync result code.
529 539
530 aio_fdatasync $fh, $callback->($status) 540 aio_fdatasync $fh, $callback->($status)
531 Asynchronously call fdatasync on the given filehandle and call the 541 Asynchronously call fdatasync on the given filehandle and call the
532 callback with the fdatasync result code. 542 callback with the fdatasync result code.
533 543
534 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
535 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.
536 556
537 aio_group $callback->(...) 557 aio_group $callback->(...)
538 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
539 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
540 to bundle many requests into a single, composite, request with a 560 to bundle many requests into a single, composite, request with a
622 }; 642 };
623 643
624 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
625 "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.
626 646
627 * 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
628 "IO::AIO::poll_cb", just like any other request. 648 "IO::AIO::poll_cb", just like any other request.
649
629 * They can be canceled like any other request. Canceling will cancel not 650 * They can be canceled like any other request. Canceling will cancel
630 only the request itself, but also all requests it contains. 651 not only the request itself, but also all requests it contains.
652
631 * 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
632 * 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
633 (or any later time). 656 (or any later time).
634 657
635 Their lifetime, simplified, looks like this: when they are empty, they 658 Their lifetime, simplified, looks like this: when they are empty, they
636 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
637 "done" state, they will also finish. Otherwise they will continue to 660 "done" state, they will also finish. Otherwise they will continue to
638 exist. 661 exist.
655 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
656 result early. 679 result early.
657 680
658 $grp->result (...) 681 $grp->result (...)
659 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
660 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
661 current value of errno (just like calling "errno" without an error 684 current value of errno (just like calling "errno" without an error
662 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.
663 686
664 $grp->errno ([$errno]) 687 $grp->errno ([$errno])
665 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
846 869
847 The default is probably ok in most situations, especially if thread 870 The default is probably ok in most situations, especially if thread
848 creation is fast. If thread creation is very slow on your system you 871 creation is fast. If thread creation is very slow on your system you
849 might want to use larger values. 872 might want to use larger values.
850 873
851 $oldmaxreqs = IO::AIO::max_outstanding $maxreqs 874 IO::AIO::max_outstanding $maxreqs
852 This is a very bad function to use in interactive programs because 875 This is a very bad function to use in interactive programs because
853 it blocks, and a bad way to reduce concurrency because it is 876 it blocks, and a bad way to reduce concurrency because it is
854 inexact: Better use an "aio_group" together with a feed callback. 877 inexact: Better use an "aio_group" together with a feed callback.
855 878
856 Sets the maximum number of outstanding requests to $nreqs. If you do 879 Sets the maximum number of outstanding requests to $nreqs. If you do
860 883
861 The default value is very large, so there is no practical limit on 884 The default value is very large, so there is no practical limit on
862 the number of outstanding requests. 885 the number of outstanding requests.
863 886
864 You can still queue as many requests as you want. Therefore, 887 You can still queue as many requests as you want. Therefore,
865 "max_oustsanding" is mainly useful in simple scripts (with low 888 "max_outstanding" is mainly useful in simple scripts (with low
866 values) or as a stop gap to shield against fatal memory overflow 889 values) or as a stop gap to shield against fatal memory overflow
867 (with large values). 890 (with large values).
868 891
869 STATISTICAL INFORMATION 892 STATISTICAL INFORMATION
870 IO::AIO::nreqs 893 IO::AIO::nreqs
920 943
921KNOWN BUGS 944KNOWN BUGS
922 Known bugs will be fixed in the next release. 945 Known bugs will be fixed in the next release.
923 946
924SEE ALSO 947SEE ALSO
925 Coro::AIO. 948 AnyEvent::AIO for easy integration into event loops, Coro::AIO for a
949 more natural syntax.
926 950
927AUTHOR 951AUTHOR
928 Marc Lehmann <schmorp@schmorp.de> 952 Marc Lehmann <schmorp@schmorp.de>
929 http://home.schmorp.de/ 953 http://home.schmorp.de/
930 954

Diff Legend

Removed lines
+ Added lines
< Changed lines
> Changed lines