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Revision 1.29 by root, Wed Apr 16 16:45:30 2008 UTC vs.
Revision 1.34 by root, Thu Nov 20 09:01:40 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, urxvt, pureperl...) 29 # AnyEvent integration (EV, Event, Glib, Tk, POE, urxvt, pureperl...)
30 open my $fh, "<&=" . IO::AIO::poll_fileno or die "$!"; 30 use AnyEvent::AIO;
31 my $w = AnyEvent->io (fh => $fh, poll => 'r', cb => sub { IO::AIO::poll_cb });
32 31
33 # EV integration 32 # EV integration
34 my $w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb; 33 my $w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb;
35 34
36 # Event integration 35 # Event integration
176 All the "aio_*" calls are more or less thin wrappers around the syscall 175 All the "aio_*" calls are more or less thin wrappers around the syscall
177 with the same name (sans "aio_"). The arguments are similar or 176 with the same name (sans "aio_"). The arguments are similar or
178 identical, and they all accept an additional (and optional) $callback 177 identical, and they all accept an additional (and optional) $callback
179 argument which must be a code reference. This code reference will get 178 argument which must be a code reference. This code reference will get
180 called with the syscall return code (e.g. most syscalls return -1 on 179 called with the syscall return code (e.g. most syscalls return -1 on
181 error, unlike perl, which usually delivers "false") as it's sole 180 error, unlike perl, which usually delivers "false") as its sole argument
182 argument when the given syscall has been executed asynchronously. 181 after the given syscall has been executed asynchronously.
183 182
184 All functions expecting a filehandle keep a copy of the filehandle 183 All functions expecting a filehandle keep a copy of the filehandle
185 internally until the request has finished. 184 internally until the request has finished.
186 185
187 All functions return request objects of type IO::AIO::REQ that allow 186 All functions return request objects of type IO::AIO::REQ that allow
200 the user environment, d) use Glib::filename_from_unicode on unicode 199 the user environment, d) use Glib::filename_from_unicode on unicode
201 filenames or e) use something else to ensure your scalar has the correct 200 filenames or e) use something else to ensure your scalar has the correct
202 contents. 201 contents.
203 202
204 This works, btw. independent of the internal UTF-8 bit, which IO::AIO 203 This works, btw. independent of the internal UTF-8 bit, which IO::AIO
205 handles correctly wether it is set or not. 204 handles correctly whether it is set or not.
206 205
207 $prev_pri = aioreq_pri [$pri] 206 $prev_pri = aioreq_pri [$pri]
208 Returns the priority value that would be used for the next request 207 Returns the priority value that would be used for the next request
209 and, if $pri is given, sets the priority for the next aio request. 208 and, if $pri is given, sets the priority for the next aio request.
210 209
452 aio_copy $srcpath, $dstpath, $callback->($status) 451 aio_copy $srcpath, $dstpath, $callback->($status)
453 Try to copy the *file* (directories not supported as either source 452 Try to copy the *file* (directories not supported as either source
454 or destination) from $srcpath to $dstpath and call the callback with 453 or destination) from $srcpath to $dstpath and call the callback with
455 the 0 (error) or -1 ok. 454 the 0 (error) or -1 ok.
456 455
457 This is a composite request that it creates the destination file 456 This is a composite request that creates the destination file with
458 with mode 0200 and copies the contents of the source file into it 457 mode 0200 and copies the contents of the source file into it using
459 using "aio_sendfile", followed by restoring atime, mtime, access 458 "aio_sendfile", followed by restoring atime, mtime, access mode and
460 mode and uid/gid, in that order. 459 uid/gid, in that order.
461 460
462 If an error occurs, the partial destination file will be unlinked, 461 If an error occurs, the partial destination file will be unlinked,
463 if possible, except when setting atime, mtime, access mode and 462 if possible, except when setting atime, mtime, access mode and
464 uid/gid, where errors are being ignored. 463 uid/gid, where errors are being ignored.
465 464
466 aio_move $srcpath, $dstpath, $callback->($status) 465 aio_move $srcpath, $dstpath, $callback->($status)
467 Try to move the *file* (directories not supported as either source 466 Try to move the *file* (directories not supported as either source
468 or destination) from $srcpath to $dstpath and call the callback with 467 or destination) from $srcpath to $dstpath and call the callback with
469 the 0 (error) or -1 ok. 468 the 0 (error) or -1 ok.
470 469
471 This is a composite request that tries to rename(2) the file first. 470 This is a composite request that tries to rename(2) the file first;
472 If rename files with "EXDEV", it copies the file with "aio_copy" 471 if rename fails with "EXDEV", it copies the file with "aio_copy"
473 and, if that is successful, unlinking the $srcpath. 472 and, if that is successful, unlinks the $srcpath.
474 473
475 aio_scandir $path, $maxreq, $callback->($dirs, $nondirs) 474 aio_scandir $path, $maxreq, $callback->($dirs, $nondirs)
476 Scans a directory (similar to "aio_readdir") but additionally tries 475 Scans a directory (similar to "aio_readdir") but additionally tries
477 to efficiently separate the entries of directory $path into two sets 476 to efficiently separate the entries of directory $path into two sets
478 of names, directories you can recurse into (directories), and ones 477 of names, directories you can recurse into (directories), and ones
543 callback with the fdatasync result code. 542 callback with the fdatasync result code.
544 543
545 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
546 be detected, it will be emulated by calling "fsync" instead. 545 be detected, it will be emulated by calling "fsync" instead.
547 546
547 aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status)
548 Sync the data portion of the file specified by $offset and $length
549 to disk (but NOT the metadata), by calling the Linux-specific
550 sync_file_range call. If sync_file_range is not available or it
551 returns ENOSYS, then fdatasync or fsync is being substituted.
552
553 $flags can be a combination of
554 "IO::AIO::SYNC_FILE_RANGE_WAIT_BEFORE",
555 "IO::AIO::SYNC_FILE_RANGE_WRITE" and
556 "IO::AIO::SYNC_FILE_RANGE_WAIT_AFTER": refer to the sync_file_range
557 manpage for details.
558
548 aio_pathsync $path, $callback->($status) 559 aio_pathsync $path, $callback->($status)
549 This request tries to open, fsync and close the given path. This is 560 This request tries to open, fsync and close the given path. This is
550 a composite request intended tosync directories after directory 561 a composite request intended to sync directories after directory
551 operations (E.g. rename). This might not work on all operating 562 operations (E.g. rename). This might not work on all operating
552 systems or have any specific effect, but usually it makes sure that 563 systems or have any specific effect, but usually it makes sure that
553 directory changes get written to disc. It works for anything that 564 directory changes get written to disc. It works for anything that
554 can be opened for read-only, not just directories. 565 can be opened for read-only, not just directories.
555 566
659 Their lifetime, simplified, looks like this: when they are empty, they 670 Their lifetime, simplified, looks like this: when they are empty, they
660 will finish very quickly. If they contain only requests that are in the 671 will finish very quickly. If they contain only requests that are in the
661 "done" state, they will also finish. Otherwise they will continue to 672 "done" state, they will also finish. Otherwise they will continue to
662 exist. 673 exist.
663 674
664 That means after creating a group you have some time to add requests. 675 That means after creating a group you have some time to add requests
665 And in the callbacks of those requests, you can add further requests to 676 (precisely before the callback has been invoked, which is only done
666 the group. And only when all those requests have finished will the the 677 within the "poll_cb"). And in the callbacks of those requests, you can
667 group itself finish. 678 add further requests to the group. And only when all those requests have
679 finished will the the group itself finish.
668 680
669 add $grp ... 681 add $grp ...
670 $grp->add (...) 682 $grp->add (...)
671 Add one or more requests to the group. Any type of IO::AIO::REQ can 683 Add one or more requests to the group. Any type of IO::AIO::REQ can
672 be added, including other groups, as long as you do not create 684 be added, including other groups, as long as you do not create
715 does not impose any limits). 727 does not impose any limits).
716 728
717 If the feed does not queue more requests when called, it will be 729 If the feed does not queue more requests when called, it will be
718 automatically removed from the group. 730 automatically removed from the group.
719 731
720 If the feed limit is 0, it will be set to 2 automatically. 732 If the feed limit is 0 when this method is called, it will be set to
733 2 automatically.
721 734
722 Example: 735 Example:
723 736
724 # stat all files in @files, but only ever use four aio requests concurrently: 737 # stat all files in @files, but only ever use four aio requests concurrently:
725 738
735 limit $grp $num 748 limit $grp $num
736 Sets the feeder limit for the group: The feeder will be called 749 Sets the feeder limit for the group: The feeder will be called
737 whenever the group contains less than this many requests. 750 whenever the group contains less than this many requests.
738 751
739 Setting the limit to 0 will pause the feeding process. 752 Setting the limit to 0 will pause the feeding process.
753
754 The default value for the limit is 0, but note that setting a feeder
755 automatically bumps it up to 2.
740 756
741 SUPPORT FUNCTIONS 757 SUPPORT FUNCTIONS
742 EVENT PROCESSING AND EVENT LOOP INTEGRATION 758 EVENT PROCESSING AND EVENT LOOP INTEGRATION
743 $fileno = IO::AIO::poll_fileno 759 $fileno = IO::AIO::poll_fileno
744 Return the *request result pipe file descriptor*. This filehandle 760 Return the *request result pipe file descriptor*. This filehandle
748 764
749 See "poll_cb" for an example. 765 See "poll_cb" for an example.
750 766
751 IO::AIO::poll_cb 767 IO::AIO::poll_cb
752 Process some outstanding events on the result pipe. You have to call 768 Process some outstanding events on the result pipe. You have to call
753 this regularly. Returns the number of events processed. Returns 769 this regularly. Returns 0 if all events could be processed, or -1 if
754 immediately when no events are outstanding. The amount of events 770 it returned earlier for whatever reason. Returns immediately when no
771 events are outstanding. The amount of events processed depends on
755 processed depends on the settings of "IO::AIO::max_poll_req" and 772 the settings of "IO::AIO::max_poll_req" and
756 "IO::AIO::max_poll_time". 773 "IO::AIO::max_poll_time".
757 774
758 If not all requests were processed for whatever reason, the 775 If not all requests were processed for whatever reason, the
759 filehandle will still be ready when "poll_cb" returns. 776 filehandle will still be ready when "poll_cb" returns, so normally
777 you don't have to do anything special to have it called later.
760 778
761 Example: Install an Event watcher that automatically calls 779 Example: Install an Event watcher that automatically calls
762 IO::AIO::poll_cb with high priority: 780 IO::AIO::poll_cb with high priority:
763 781
764 Event->io (fd => IO::AIO::poll_fileno, 782 Event->io (fd => IO::AIO::poll_fileno,
870 888
871 The default is probably ok in most situations, especially if thread 889 The default is probably ok in most situations, especially if thread
872 creation is fast. If thread creation is very slow on your system you 890 creation is fast. If thread creation is very slow on your system you
873 might want to use larger values. 891 might want to use larger values.
874 892
875 $oldmaxreqs = IO::AIO::max_outstanding $maxreqs 893 IO::AIO::max_outstanding $maxreqs
876 This is a very bad function to use in interactive programs because 894 This is a very bad function to use in interactive programs because
877 it blocks, and a bad way to reduce concurrency because it is 895 it blocks, and a bad way to reduce concurrency because it is
878 inexact: Better use an "aio_group" together with a feed callback. 896 inexact: Better use an "aio_group" together with a feed callback.
879 897
880 Sets the maximum number of outstanding requests to $nreqs. If you do 898 Sets the maximum number of outstanding requests to $nreqs. If you do
884 902
885 The default value is very large, so there is no practical limit on 903 The default value is very large, so there is no practical limit on
886 the number of outstanding requests. 904 the number of outstanding requests.
887 905
888 You can still queue as many requests as you want. Therefore, 906 You can still queue as many requests as you want. Therefore,
889 "max_oustsanding" is mainly useful in simple scripts (with low 907 "max_outstanding" is mainly useful in simple scripts (with low
890 values) or as a stop gap to shield against fatal memory overflow 908 values) or as a stop gap to shield against fatal memory overflow
891 (with large values). 909 (with large values).
892 910
893 STATISTICAL INFORMATION 911 STATISTICAL INFORMATION
894 IO::AIO::nreqs 912 IO::AIO::nreqs
944 962
945KNOWN BUGS 963KNOWN BUGS
946 Known bugs will be fixed in the next release. 964 Known bugs will be fixed in the next release.
947 965
948SEE ALSO 966SEE ALSO
949 Coro::AIO. 967 AnyEvent::AIO for easy integration into event loops, Coro::AIO for a
968 more natural syntax.
950 969
951AUTHOR 970AUTHOR
952 Marc Lehmann <schmorp@schmorp.de> 971 Marc Lehmann <schmorp@schmorp.de>
953 http://home.schmorp.de/ 972 http://home.schmorp.de/
954 973

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