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Comparing IO-AIO/AIO.pm (file contents):
Revision 1.122 by root, Sat Apr 26 12:00:23 2008 UTC vs.
Revision 1.142 by root, Wed Oct 22 18:15:36 2008 UTC

… …
26 $req->cancel; # cancel request if still in queue 26 $req->cancel; # cancel request if still in queue
27 27
28 my $grp = aio_group sub { print "all stats done\n" }; 28 my $grp = aio_group sub { print "all stats done\n" };
29 add $grp aio_stat "..." for ...; 29 add $grp aio_stat "..." for ...;
30 30
31 # AnyEvent integration (EV, Event, Glib, Tk, urxvt, pureperl...) 31 # AnyEvent integration (EV, Event, Glib, Tk, POE, urxvt, pureperl...)
32 open my $fh, "<&=" . IO::AIO::poll_fileno or die "$!"; 32 use AnyEvent::AIO;
33 my $w = AnyEvent->io (fh => $fh, poll => 'r', cb => sub { IO::AIO::poll_cb });
34 33
35 # EV integration 34 # EV integration
36 my $w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb; 35 my $w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb;
37 36
38 # Event integration 37 # Event integration
… …
194use strict 'vars'; 193use strict 'vars';
195 194
196use base 'Exporter'; 195use base 'Exporter';
197 196
198BEGIN { 197BEGIN {
199 our $VERSION = '2.62'; 198 our $VERSION = '3.16';
200 199
201 our @AIO_REQ = qw(aio_sendfile aio_read aio_write aio_open aio_close 200 our @AIO_REQ = qw(aio_sendfile aio_read aio_write aio_open aio_close
202 aio_stat aio_lstat aio_unlink aio_rmdir aio_readdir 201 aio_stat aio_lstat aio_unlink aio_rmdir aio_readdir
203 aio_scandir aio_symlink aio_readlink aio_sync aio_fsync 202 aio_scandir aio_symlink aio_readlink aio_sync aio_fsync
204 aio_fdatasync aio_pathsync aio_readahead 203 aio_fdatasync aio_sync_file_range aio_pathsync aio_readahead
205 aio_rename aio_link aio_move aio_copy aio_group 204 aio_rename aio_link aio_move aio_copy aio_group
206 aio_nop aio_mknod aio_load aio_rmtree aio_mkdir aio_chown 205 aio_nop aio_mknod aio_load aio_rmtree aio_mkdir aio_chown
207 aio_chmod aio_utime aio_truncate); 206 aio_chmod aio_utime aio_truncate);
208 207
209 our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice aio_block)); 208 our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice));
210 our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush 209 our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush
211 min_parallel max_parallel max_idle 210 min_parallel max_parallel max_idle
212 nreqs nready npending nthreads 211 nreqs nready npending nthreads
213 max_poll_time max_poll_reqs); 212 max_poll_time max_poll_reqs);
214 213
… …
225All the C<aio_*> calls are more or less thin wrappers around the syscall 224All the C<aio_*> calls are more or less thin wrappers around the syscall
226with the same name (sans C<aio_>). The arguments are similar or identical, 225with the same name (sans C<aio_>). The arguments are similar or identical,
227and they all accept an additional (and optional) C<$callback> argument 226and they all accept an additional (and optional) C<$callback> argument
228which must be a code reference. This code reference will get called with 227which must be a code reference. This code reference will get called with
229the syscall return code (e.g. most syscalls return C<-1> on error, unlike 228the syscall return code (e.g. most syscalls return C<-1> on error, unlike
230perl, which usually delivers "false") as it's sole argument when the given 229perl, which usually delivers "false") as its sole argument after the given
231syscall has been executed asynchronously. 230syscall has been executed asynchronously.
232 231
233All functions expecting a filehandle keep a copy of the filehandle 232All functions expecting a filehandle keep a copy of the filehandle
234internally until the request has finished. 233internally until the request has finished.
235 234
… …
249your pathnames to the locale (or other) encoding in effect in the user 248your pathnames to the locale (or other) encoding in effect in the user
250environment, d) use Glib::filename_from_unicode on unicode filenames or e) 249environment, d) use Glib::filename_from_unicode on unicode filenames or e)
251use something else to ensure your scalar has the correct contents. 250use something else to ensure your scalar has the correct contents.
252 251
253This works, btw. independent of the internal UTF-8 bit, which IO::AIO 252This works, btw. independent of the internal UTF-8 bit, which IO::AIO
254handles correctly wether it is set or not. 253handles correctly whether it is set or not.
255 254
256=over 4 255=over 4
257 256
258=item $prev_pri = aioreq_pri [$pri] 257=item $prev_pri = aioreq_pri [$pri]
259 258
… …
540memory. Status is the same as with aio_read. 539memory. Status is the same as with aio_read.
541 540
542=cut 541=cut
543 542
544sub aio_load($$;$) { 543sub aio_load($$;$) {
545 aio_block {
546 my ($path, undef, $cb) = @_; 544 my ($path, undef, $cb) = @_;
547 my $data = \$_[1]; 545 my $data = \$_[1];
548 546
549 my $pri = aioreq_pri; 547 my $pri = aioreq_pri;
550 my $grp = aio_group $cb; 548 my $grp = aio_group $cb;
549
550 aioreq_pri $pri;
551 add $grp aio_open $path, O_RDONLY, 0, sub {
552 my $fh = shift
553 or return $grp->result (-1);
551 554
552 aioreq_pri $pri; 555 aioreq_pri $pri;
553 add $grp aio_open $path, O_RDONLY, 0, sub {
554 my $fh = shift
555 or return $grp->result (-1);
556
557 aioreq_pri $pri;
558 add $grp aio_read $fh, 0, (-s $fh), $$data, 0, sub { 556 add $grp aio_read $fh, 0, (-s $fh), $$data, 0, sub {
559 $grp->result ($_[0]); 557 $grp->result ($_[0]);
560 };
561 }; 558 };
562
563 $grp
564 } 559 };
560
561 $grp
565} 562}
566 563
567=item aio_copy $srcpath, $dstpath, $callback->($status) 564=item aio_copy $srcpath, $dstpath, $callback->($status)
568 565
569Try to copy the I<file> (directories not supported as either source or 566Try to copy the I<file> (directories not supported as either source or
570destination) from C<$srcpath> to C<$dstpath> and call the callback with 567destination) from C<$srcpath> to C<$dstpath> and call the callback with
571the C<0> (error) or C<-1> ok. 568the C<0> (error) or C<-1> ok.
572 569
573This is a composite request that it creates the destination file with 570This is a composite request that creates the destination file with
574mode 0200 and copies the contents of the source file into it using 571mode 0200 and copies the contents of the source file into it using
575C<aio_sendfile>, followed by restoring atime, mtime, access mode and 572C<aio_sendfile>, followed by restoring atime, mtime, access mode and
576uid/gid, in that order. 573uid/gid, in that order.
577 574
578If an error occurs, the partial destination file will be unlinked, if 575If an error occurs, the partial destination file will be unlinked, if
… …
580errors are being ignored. 577errors are being ignored.
581 578
582=cut 579=cut
583 580
584sub aio_copy($$;$) { 581sub aio_copy($$;$) {
585 aio_block {
586 my ($src, $dst, $cb) = @_; 582 my ($src, $dst, $cb) = @_;
587 583
588 my $pri = aioreq_pri; 584 my $pri = aioreq_pri;
589 my $grp = aio_group $cb; 585 my $grp = aio_group $cb;
590 586
591 aioreq_pri $pri; 587 aioreq_pri $pri;
592 add $grp aio_open $src, O_RDONLY, 0, sub { 588 add $grp aio_open $src, O_RDONLY, 0, sub {
593 if (my $src_fh = $_[0]) { 589 if (my $src_fh = $_[0]) {
594 my @stat = stat $src_fh; 590 my @stat = stat $src_fh;
595 591
596 aioreq_pri $pri; 592 aioreq_pri $pri;
597 add $grp aio_open $dst, O_CREAT | O_WRONLY | O_TRUNC, 0200, sub { 593 add $grp aio_open $dst, O_CREAT | O_WRONLY | O_TRUNC, 0200, sub {
598 if (my $dst_fh = $_[0]) { 594 if (my $dst_fh = $_[0]) {
599 aioreq_pri $pri; 595 aioreq_pri $pri;
600 add $grp aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub { 596 add $grp aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub {
601 if ($_[0] == $stat[7]) { 597 if ($_[0] == $stat[7]) {
602 $grp->result (0); 598 $grp->result (0);
603 close $src_fh; 599 close $src_fh;
604 600
605 # those should not normally block. should. should. 601 # those should not normally block. should. should.
606 utime $stat[8], $stat[9], $dst; 602 utime $stat[8], $stat[9], $dst;
607 chmod $stat[2] & 07777, $dst_fh; 603 chmod $stat[2] & 07777, $dst_fh;
608 chown $stat[4], $stat[5], $dst_fh; 604 chown $stat[4], $stat[5], $dst_fh;
609 605
610 aioreq_pri $pri; 606 aioreq_pri $pri;
611 add $grp aio_close $dst_fh; 607 add $grp aio_close $dst_fh;
612 } else { 608 } else {
613 $grp->result (-1); 609 $grp->result (-1);
614 close $src_fh; 610 close $src_fh;
615 close $dst_fh; 611 close $dst_fh;
616 612
617 aioreq $pri; 613 aioreq $pri;
618 add $grp aio_unlink $dst; 614 add $grp aio_unlink $dst;
619 }
620 }; 615 }
621 } else {
622 $grp->result (-1);
623 } 616 };
617 } else {
618 $grp->result (-1);
624 }, 619 }
625
626 } else {
627 $grp->result (-1);
628 } 620 },
621
622 } else {
623 $grp->result (-1);
629 }; 624 }
630
631 $grp
632 } 625 };
626
627 $grp
633} 628}
634 629
635=item aio_move $srcpath, $dstpath, $callback->($status) 630=item aio_move $srcpath, $dstpath, $callback->($status)
636 631
637Try to move the I<file> (directories not supported as either source or 632Try to move the I<file> (directories not supported as either source or
638destination) from C<$srcpath> to C<$dstpath> and call the callback with 633destination) from C<$srcpath> to C<$dstpath> and call the callback with
639the C<0> (error) or C<-1> ok. 634the C<0> (error) or C<-1> ok.
640 635
641This is a composite request that tries to rename(2) the file first. If 636This is a composite request that tries to rename(2) the file first; if
642rename files with C<EXDEV>, it copies the file with C<aio_copy> and, if 637rename fails with C<EXDEV>, it copies the file with C<aio_copy> and, if
643that is successful, unlinking the C<$srcpath>. 638that is successful, unlinks the C<$srcpath>.
644 639
645=cut 640=cut
646 641
647sub aio_move($$;$) { 642sub aio_move($$;$) {
648 aio_block {
649 my ($src, $dst, $cb) = @_; 643 my ($src, $dst, $cb) = @_;
650 644
651 my $pri = aioreq_pri; 645 my $pri = aioreq_pri;
652 my $grp = aio_group $cb; 646 my $grp = aio_group $cb;
653 647
654 aioreq_pri $pri; 648 aioreq_pri $pri;
655 add $grp aio_rename $src, $dst, sub { 649 add $grp aio_rename $src, $dst, sub {
656 if ($_[0] && $! == EXDEV) { 650 if ($_[0] && $! == EXDEV) {
657 aioreq_pri $pri; 651 aioreq_pri $pri;
658 add $grp aio_copy $src, $dst, sub { 652 add $grp aio_copy $src, $dst, sub {
659 $grp->result ($_[0]);
660
661 if (!$_[0]) {
662 aioreq_pri $pri;
663 add $grp aio_unlink $src;
664 }
665 };
666 } else {
667 $grp->result ($_[0]); 653 $grp->result ($_[0]);
654
655 if (!$_[0]) {
656 aioreq_pri $pri;
657 add $grp aio_unlink $src;
658 }
668 } 659 };
660 } else {
661 $grp->result ($_[0]);
669 }; 662 }
670
671 $grp
672 } 663 };
664
665 $grp
673} 666}
674 667
675=item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs) 668=item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs)
676 669
677Scans a directory (similar to C<aio_readdir>) but additionally tries to 670Scans a directory (similar to C<aio_readdir>) but additionally tries to
… …
725directory counting heuristic. 718directory counting heuristic.
726 719
727=cut 720=cut
728 721
729sub aio_scandir($$;$) { 722sub aio_scandir($$;$) {
730 aio_block {
731 my ($path, $maxreq, $cb) = @_; 723 my ($path, $maxreq, $cb) = @_;
732 724
733 my $pri = aioreq_pri; 725 my $pri = aioreq_pri;
734 726
735 my $grp = aio_group $cb; 727 my $grp = aio_group $cb;
736 728
737 $maxreq = 4 if $maxreq <= 0; 729 $maxreq = 4 if $maxreq <= 0;
738 730
739 # stat once 731 # stat once
732 aioreq_pri $pri;
733 add $grp aio_stat $path, sub {
734 return $grp->result () if $_[0];
735 my $now = time;
736 my $hash1 = join ":", (stat _)[0,1,3,7,9];
737
738 # read the directory entries
740 aioreq_pri $pri; 739 aioreq_pri $pri;
741 add $grp aio_stat $path, sub { 740 add $grp aio_readdir $path, sub {
741 my $entries = shift
742 return $grp->result () if $_[0]; 742 or return $grp->result ();
743 my $now = time;
744 my $hash1 = join ":", (stat _)[0,1,3,7,9];
745 743
746 # read the directory entries 744 # stat the dir another time
747 aioreq_pri $pri; 745 aioreq_pri $pri;
748 add $grp aio_readdir $path, sub {
749 my $entries = shift
750 or return $grp->result ();
751
752 # stat the dir another time
753 aioreq_pri $pri;
754 add $grp aio_stat $path, sub { 746 add $grp aio_stat $path, sub {
755 my $hash2 = join ":", (stat _)[0,1,3,7,9]; 747 my $hash2 = join ":", (stat _)[0,1,3,7,9];
756 748
757 my $ndirs; 749 my $ndirs;
758 750
759 # take the slow route if anything looks fishy 751 # take the slow route if anything looks fishy
760 if ($hash1 ne $hash2 or (stat _)[9] == $now) { 752 if ($hash1 ne $hash2 or (stat _)[9] == $now) {
761 $ndirs = -1; 753 $ndirs = -1;
762 } else { 754 } else {
763 # if nlink == 2, we are finished 755 # if nlink == 2, we are finished
764 # on non-posix-fs's, we rely on nlink < 2 756 # on non-posix-fs's, we rely on nlink < 2
765 $ndirs = (stat _)[3] - 2 757 $ndirs = (stat _)[3] - 2
766 or return $grp->result ([], $entries); 758 or return $grp->result ([], $entries);
767 } 759 }
768 760
769 # sort into likely dirs and likely nondirs 761 # sort into likely dirs and likely nondirs
770 # dirs == files without ".", short entries first 762 # dirs == files without ".", short entries first
771 $entries = [map $_->[0], 763 $entries = [map $_->[0],
772 sort { $b->[1] cmp $a->[1] } 764 sort { $b->[1] cmp $a->[1] }
773 map [$_, sprintf "%s%04d", (/.\./ ? "1" : "0"), length], 765 map [$_, sprintf "%s%04d", (/.\./ ? "1" : "0"), length],
774 @$entries]; 766 @$entries];
775 767
776 my (@dirs, @nondirs); 768 my (@dirs, @nondirs);
777 769
778 my $statgrp = add $grp aio_group sub { 770 my $statgrp = add $grp aio_group sub {
779 $grp->result (\@dirs, \@nondirs); 771 $grp->result (\@dirs, \@nondirs);
780 }; 772 };
781 773
782 limit $statgrp $maxreq; 774 limit $statgrp $maxreq;
783 feed $statgrp sub { 775 feed $statgrp sub {
784 return unless @$entries; 776 return unless @$entries;
785 my $entry = pop @$entries; 777 my $entry = pop @$entries;
786 778
787 aioreq_pri $pri; 779 aioreq_pri $pri;
788 add $statgrp aio_stat "$path/$entry/.", sub { 780 add $statgrp aio_stat "$path/$entry/.", sub {
789 if ($_[0] < 0) { 781 if ($_[0] < 0) {
790 push @nondirs, $entry; 782 push @nondirs, $entry;
791 } else { 783 } else {
792 # need to check for real directory 784 # need to check for real directory
793 aioreq_pri $pri; 785 aioreq_pri $pri;
794 add $statgrp aio_lstat "$path/$entry", sub { 786 add $statgrp aio_lstat "$path/$entry", sub {
795 if (-d _) { 787 if (-d _) {
796 push @dirs, $entry; 788 push @dirs, $entry;
797 789
798 unless (--$ndirs) { 790 unless (--$ndirs) {
799 push @nondirs, @$entries; 791 push @nondirs, @$entries;
800 feed $statgrp; 792 feed $statgrp;
801 }
802 } else {
803 push @nondirs, $entry;
804 } 793 }
794 } else {
795 push @nondirs, $entry;
805 } 796 }
806 } 797 }
807 }; 798 }
808 }; 799 };
809 }; 800 };
810 }; 801 };
811 }; 802 };
812
813 $grp
814 } 803 };
804
805 $grp
815} 806}
816 807
817=item aio_rmtree $path, $callback->($status) 808=item aio_rmtree $path, $callback->($status)
818 809
819Delete a directory tree starting (and including) C<$path>, return the 810Delete a directory tree starting (and including) C<$path>, return the
… …
823 814
824=cut 815=cut
825 816
826sub aio_rmtree; 817sub aio_rmtree;
827sub aio_rmtree($;$) { 818sub aio_rmtree($;$) {
828 aio_block {
829 my ($path, $cb) = @_; 819 my ($path, $cb) = @_;
830 820
831 my $pri = aioreq_pri; 821 my $pri = aioreq_pri;
832 my $grp = aio_group $cb; 822 my $grp = aio_group $cb;
833 823
834 aioreq_pri $pri; 824 aioreq_pri $pri;
835 add $grp aio_scandir $path, 0, sub { 825 add $grp aio_scandir $path, 0, sub {
836 my ($dirs, $nondirs) = @_; 826 my ($dirs, $nondirs) = @_;
837 827
838 my $dirgrp = aio_group sub { 828 my $dirgrp = aio_group sub {
839 add $grp aio_rmdir $path, sub { 829 add $grp aio_rmdir $path, sub {
840 $grp->result ($_[0]); 830 $grp->result ($_[0]);
841 };
842 }; 831 };
843
844 (aioreq_pri $pri), add $dirgrp aio_rmtree "$path/$_" for @$dirs;
845 (aioreq_pri $pri), add $dirgrp aio_unlink "$path/$_" for @$nondirs;
846
847 add $grp $dirgrp;
848 }; 832 };
849 833
850 $grp 834 (aioreq_pri $pri), add $dirgrp aio_rmtree "$path/$_" for @$dirs;
835 (aioreq_pri $pri), add $dirgrp aio_unlink "$path/$_" for @$nondirs;
836
837 add $grp $dirgrp;
851 } 838 };
839
840 $grp
852} 841}
853 842
854=item aio_sync $callback->($status) 843=item aio_sync $callback->($status)
855 844
856Asynchronously call sync and call the callback when finished. 845Asynchronously call sync and call the callback when finished.
… …
866callback with the fdatasync result code. 855callback with the fdatasync result code.
867 856
868If this call isn't available because your OS lacks it or it couldn't be 857If this call isn't available because your OS lacks it or it couldn't be
869detected, it will be emulated by calling C<fsync> instead. 858detected, it will be emulated by calling C<fsync> instead.
870 859
860=item aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status)
861
862Sync the data portion of the file specified by C<$offset> and C<$length>
863to disk (but NOT the metadata), by calling the Linux-specific
864sync_file_range call. If sync_file_range is not available or it returns
865ENOSYS, then fdatasync or fsync is being substituted.
866
867C<$flags> can be a combination of C<IO::AIO::SYNC_FILE_RANGE_WAIT_BEFORE>,
868C<IO::AIO::SYNC_FILE_RANGE_WRITE> and
869C<IO::AIO::SYNC_FILE_RANGE_WAIT_AFTER>: refer to the sync_file_range
870manpage for details.
871
871=item aio_pathsync $path, $callback->($status) 872=item aio_pathsync $path, $callback->($status)
872 873
873This request tries to open, fsync and close the given path. This is a 874This request tries to open, fsync and close the given path. This is a
874composite request intended tosync directories after directory operations 875composite request intended to sync directories after directory operations
875(E.g. rename). This might not work on all operating systems or have any 876(E.g. rename). This might not work on all operating systems or have any
876specific effect, but usually it makes sure that directory changes get 877specific effect, but usually it makes sure that directory changes get
877written to disc. It works for anything that can be opened for read-only, 878written to disc. It works for anything that can be opened for read-only,
878not just directories. 879not just directories.
879 880
880Passes C<0> when everything went ok, and C<-1> on error. 881Passes C<0> when everything went ok, and C<-1> on error.
881 882
882=cut 883=cut
883 884
884sub aio_pathsync($;$) { 885sub aio_pathsync($;$) {
885 aio_block {
886 my ($path, $cb) = @_; 886 my ($path, $cb) = @_;
887 887
888 my $pri = aioreq_pri; 888 my $pri = aioreq_pri;
889 my $grp = aio_group $cb; 889 my $grp = aio_group $cb;
890 890
891 aioreq_pri $pri; 891 aioreq_pri $pri;
892 add $grp aio_open $path, O_RDONLY, 0, sub { 892 add $grp aio_open $path, O_RDONLY, 0, sub {
893 my ($fh) = @_; 893 my ($fh) = @_;
894 if ($fh) { 894 if ($fh) {
895 aioreq_pri $pri;
896 add $grp aio_fsync $fh, sub {
897 $grp->result ($_[0]);
898
895 aioreq_pri $pri; 899 aioreq_pri $pri;
896 add $grp aio_fsync $fh, sub {
897 $grp->result ($_[0]);
898
899 aioreq_pri $pri;
900 add $grp aio_close $fh; 900 add $grp aio_close $fh;
901 };
902 } else {
903 $grp->result (-1);
904 } 901 };
902 } else {
903 $grp->result (-1);
905 }; 904 }
906
907 $grp
908 } 905 };
906
907 $grp
909} 908}
910 909
911=item aio_group $callback->(...) 910=item aio_group $callback->(...)
912 911
913This is a very special aio request: Instead of doing something, it is a 912This is a very special aio request: Instead of doing something, it is a
… …
1026Their lifetime, simplified, looks like this: when they are empty, they 1025Their lifetime, simplified, looks like this: when they are empty, they
1027will finish very quickly. If they contain only requests that are in the 1026will finish very quickly. If they contain only requests that are in the
1028C<done> state, they will also finish. Otherwise they will continue to 1027C<done> state, they will also finish. Otherwise they will continue to
1029exist. 1028exist.
1030 1029
1031That means after creating a group you have some time to add requests. And 1030That means after creating a group you have some time to add requests
1032in the callbacks of those requests, you can add further requests to the 1031(precisely before the callback has been invoked, which is only done within
1033group. And only when all those requests have finished will the the group 1032the C<poll_cb>). And in the callbacks of those requests, you can add
1034itself finish. 1033further requests to the group. And only when all those requests have
1034finished will the the group itself finish.
1035 1035
1036=over 4 1036=over 4
1037 1037
1038=item add $grp ... 1038=item add $grp ...
1039 1039
… …
1072=item feed $grp $callback->($grp) 1072=item feed $grp $callback->($grp)
1073 1073
1074Sets a feeder/generator on this group: every group can have an attached 1074Sets a feeder/generator on this group: every group can have an attached
1075generator that generates requests if idle. The idea behind this is that, 1075generator that generates requests if idle. The idea behind this is that,
1076although you could just queue as many requests as you want in a group, 1076although you could just queue as many requests as you want in a group,
1077this might starve other requests for a potentially long time. For 1077this might starve other requests for a potentially long time. For example,
1078example, C<aio_scandir> might generate hundreds of thousands C<aio_stat> 1078C<aio_scandir> might generate hundreds of thousands C<aio_stat> requests,
1079requests, delaying any later requests for a long time. 1079delaying any later requests for a long time.
1080 1080
1081To avoid this, and allow incremental generation of requests, you can 1081To avoid this, and allow incremental generation of requests, you can
1082instead a group and set a feeder on it that generates those requests. The 1082instead a group and set a feeder on it that generates those requests. The
1083feed callback will be called whenever there are few enough (see C<limit>, 1083feed callback will be called whenever there are few enough (see C<limit>,
1084below) requests active in the group itself and is expected to queue more 1084below) requests active in the group itself and is expected to queue more
… …
1088not impose any limits). 1088not impose any limits).
1089 1089
1090If the feed does not queue more requests when called, it will be 1090If the feed does not queue more requests when called, it will be
1091automatically removed from the group. 1091automatically removed from the group.
1092 1092
1093If the feed limit is C<0>, it will be set to C<2> automatically. 1093If the feed limit is C<0> when this method is called, it will be set to
1094C<2> automatically.
1094 1095
1095Example: 1096Example:
1096 1097
1097 # stat all files in @files, but only ever use four aio requests concurrently: 1098 # stat all files in @files, but only ever use four aio requests concurrently:
1098 1099
… …
1110Sets the feeder limit for the group: The feeder will be called whenever 1111Sets the feeder limit for the group: The feeder will be called whenever
1111the group contains less than this many requests. 1112the group contains less than this many requests.
1112 1113
1113Setting the limit to C<0> will pause the feeding process. 1114Setting the limit to C<0> will pause the feeding process.
1114 1115
1116The default value for the limit is C<0>, but note that setting a feeder
1117automatically bumps it up to C<2>.
1118
1115=back 1119=back
1116 1120
1117=head2 SUPPORT FUNCTIONS 1121=head2 SUPPORT FUNCTIONS
1118 1122
1119=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION 1123=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION
… …
1130See C<poll_cb> for an example. 1134See C<poll_cb> for an example.
1131 1135
1132=item IO::AIO::poll_cb 1136=item IO::AIO::poll_cb
1133 1137
1134Process some outstanding events on the result pipe. You have to call this 1138Process some outstanding events on the result pipe. You have to call this
1135regularly. Returns the number of events processed. Returns immediately 1139regularly. Returns C<0> if all events could be processed, or C<-1> if it
1140returned earlier for whatever reason. Returns immediately when no events
1136when no events are outstanding. The amount of events processed depends on 1141are outstanding. The amount of events processed depends on the settings of
1137the settings of C<IO::AIO::max_poll_req> and C<IO::AIO::max_poll_time>. 1142C<IO::AIO::max_poll_req> and C<IO::AIO::max_poll_time>.
1138 1143
1139If not all requests were processed for whatever reason, the filehandle 1144If not all requests were processed for whatever reason, the filehandle
1140will still be ready when C<poll_cb> returns. 1145will still be ready when C<poll_cb> returns, so normally you don't have to
1146do anything special to have it called later.
1141 1147
1142Example: Install an Event watcher that automatically calls 1148Example: Install an Event watcher that automatically calls
1143IO::AIO::poll_cb with high priority: 1149IO::AIO::poll_cb with high priority:
1144 1150
1145 Event->io (fd => IO::AIO::poll_fileno, 1151 Event->io (fd => IO::AIO::poll_fileno,
… …
1259 1265
1260The default is probably ok in most situations, especially if thread 1266The default is probably ok in most situations, especially if thread
1261creation is fast. If thread creation is very slow on your system you might 1267creation is fast. If thread creation is very slow on your system you might
1262want to use larger values. 1268want to use larger values.
1263 1269
1264=item $oldmaxreqs = IO::AIO::max_outstanding $maxreqs 1270=item IO::AIO::max_outstanding $maxreqs
1265 1271
1266This is a very bad function to use in interactive programs because it 1272This is a very bad function to use in interactive programs because it
1267blocks, and a bad way to reduce concurrency because it is inexact: Better 1273blocks, and a bad way to reduce concurrency because it is inexact: Better
1268use an C<aio_group> together with a feed callback. 1274use an C<aio_group> together with a feed callback.
1269 1275
… …
1274 1280
1275The default value is very large, so there is no practical limit on the 1281The default value is very large, so there is no practical limit on the
1276number of outstanding requests. 1282number of outstanding requests.
1277 1283
1278You can still queue as many requests as you want. Therefore, 1284You can still queue as many requests as you want. Therefore,
1279C<max_oustsanding> is mainly useful in simple scripts (with low values) or 1285C<max_outstanding> is mainly useful in simple scripts (with low values) or
1280as a stop gap to shield against fatal memory overflow (with large values). 1286as a stop gap to shield against fatal memory overflow (with large values).
1281 1287
1282=back 1288=back
1283 1289
1284=head3 STATISTICAL INFORMATION 1290=head3 STATISTICAL INFORMATION
… …
1354 1360
1355Known bugs will be fixed in the next release. 1361Known bugs will be fixed in the next release.
1356 1362
1357=head1 SEE ALSO 1363=head1 SEE ALSO
1358 1364
1359L<Coro::AIO>. 1365L<AnyEvent::AIO> for easy integration into event loops, L<Coro::AIO> for a
1366more natural syntax.
1360 1367
1361=head1 AUTHOR 1368=head1 AUTHOR
1362 1369
1363 Marc Lehmann <schmorp@schmorp.de> 1370 Marc Lehmann <schmorp@schmorp.de>
1364 http://home.schmorp.de/ 1371 http://home.schmorp.de/

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