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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 1.144 by root, Sun Apr 19 19:17:59 2009 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 = '3.18';
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);
213
214 push @AIO_REQ, qw(aio_busy); # not exported
214 215
215 @IO::AIO::GRP::ISA = 'IO::AIO::REQ'; 216 @IO::AIO::GRP::ISA = 'IO::AIO::REQ';
216 217
217 require XSLoader; 218 require XSLoader;
218 XSLoader::load ("IO::AIO", $VERSION); 219 XSLoader::load ("IO::AIO", $VERSION);
… …
225All the C<aio_*> calls are more or less thin wrappers around the syscall 226All the C<aio_*> calls are more or less thin wrappers around the syscall
226with the same name (sans C<aio_>). The arguments are similar or identical, 227with the same name (sans C<aio_>). The arguments are similar or identical,
227and they all accept an additional (and optional) C<$callback> argument 228and they all accept an additional (and optional) C<$callback> argument
228which must be a code reference. This code reference will get called with 229which 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 230the 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 231perl, which usually delivers "false") as its sole argument after the given
231syscall has been executed asynchronously. 232syscall has been executed asynchronously.
232 233
233All functions expecting a filehandle keep a copy of the filehandle 234All functions expecting a filehandle keep a copy of the filehandle
234internally until the request has finished. 235internally until the request has finished.
235 236
… …
249your pathnames to the locale (or other) encoding in effect in the user 250your pathnames to the locale (or other) encoding in effect in the user
250environment, d) use Glib::filename_from_unicode on unicode filenames or e) 251environment, d) use Glib::filename_from_unicode on unicode filenames or e)
251use something else to ensure your scalar has the correct contents. 252use something else to ensure your scalar has the correct contents.
252 253
253This works, btw. independent of the internal UTF-8 bit, which IO::AIO 254This works, btw. independent of the internal UTF-8 bit, which IO::AIO
254handles correctly wether it is set or not. 255handles correctly whether it is set or not.
255 256
256=over 4 257=over 4
257 258
258=item $prev_pri = aioreq_pri [$pri] 259=item $prev_pri = aioreq_pri [$pri]
259 260
… …
540memory. Status is the same as with aio_read. 541memory. Status is the same as with aio_read.
541 542
542=cut 543=cut
543 544
544sub aio_load($$;$) { 545sub aio_load($$;$) {
545 aio_block {
546 my ($path, undef, $cb) = @_; 546 my ($path, undef, $cb) = @_;
547 my $data = \$_[1]; 547 my $data = \$_[1];
548 548
549 my $pri = aioreq_pri; 549 my $pri = aioreq_pri;
550 my $grp = aio_group $cb; 550 my $grp = aio_group $cb;
551
552 aioreq_pri $pri;
553 add $grp aio_open $path, O_RDONLY, 0, sub {
554 my $fh = shift
555 or return $grp->result (-1);
551 556
552 aioreq_pri $pri; 557 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), $$data, 0, sub { 558 add $grp aio_read $fh, 0, (-s $fh), $$data, 0, sub {
559 $grp->result ($_[0]); 559 $grp->result ($_[0]);
560 };
561 }; 560 };
562
563 $grp
564 } 561 };
562
563 $grp
565} 564}
566 565
567=item aio_copy $srcpath, $dstpath, $callback->($status) 566=item aio_copy $srcpath, $dstpath, $callback->($status)
568 567
569Try to copy the I<file> (directories not supported as either source or 568Try to copy the I<file> (directories not supported as either source or
570destination) from C<$srcpath> to C<$dstpath> and call the callback with 569destination) from C<$srcpath> to C<$dstpath> and call the callback with
571the C<0> (error) or C<-1> ok. 570the C<0> (error) or C<-1> ok.
572 571
573This is a composite request that it creates the destination file with 572This is a composite request that creates the destination file with
574mode 0200 and copies the contents of the source file into it using 573mode 0200 and copies the contents of the source file into it using
575C<aio_sendfile>, followed by restoring atime, mtime, access mode and 574C<aio_sendfile>, followed by restoring atime, mtime, access mode and
576uid/gid, in that order. 575uid/gid, in that order.
577 576
578If an error occurs, the partial destination file will be unlinked, if 577If an error occurs, the partial destination file will be unlinked, if
… …
580errors are being ignored. 579errors are being ignored.
581 580
582=cut 581=cut
583 582
584sub aio_copy($$;$) { 583sub aio_copy($$;$) {
585 aio_block {
586 my ($src, $dst, $cb) = @_; 584 my ($src, $dst, $cb) = @_;
587 585
588 my $pri = aioreq_pri; 586 my $pri = aioreq_pri;
589 my $grp = aio_group $cb; 587 my $grp = aio_group $cb;
590 588
591 aioreq_pri $pri; 589 aioreq_pri $pri;
592 add $grp aio_open $src, O_RDONLY, 0, sub { 590 add $grp aio_open $src, O_RDONLY, 0, sub {
593 if (my $src_fh = $_[0]) { 591 if (my $src_fh = $_[0]) {
594 my @stat = stat $src_fh; 592 my @stat = stat $src_fh;
595 593
596 aioreq_pri $pri; 594 aioreq_pri $pri;
597 add $grp aio_open $dst, O_CREAT | O_WRONLY | O_TRUNC, 0200, sub { 595 add $grp aio_open $dst, O_CREAT | O_WRONLY | O_TRUNC, 0200, sub {
598 if (my $dst_fh = $_[0]) { 596 if (my $dst_fh = $_[0]) {
599 aioreq_pri $pri; 597 aioreq_pri $pri;
600 add $grp aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub { 598 add $grp aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub {
601 if ($_[0] == $stat[7]) { 599 if ($_[0] == $stat[7]) {
602 $grp->result (0); 600 $grp->result (0);
603 close $src_fh; 601 close $src_fh;
604 602
605 # those should not normally block. should. should. 603 # those should not normally block. should. should.
606 utime $stat[8], $stat[9], $dst; 604 utime $stat[8], $stat[9], $dst;
607 chmod $stat[2] & 07777, $dst_fh; 605 chmod $stat[2] & 07777, $dst_fh;
608 chown $stat[4], $stat[5], $dst_fh; 606 chown $stat[4], $stat[5], $dst_fh;
609 607
610 aioreq_pri $pri; 608 aioreq_pri $pri;
611 add $grp aio_close $dst_fh; 609 add $grp aio_close $dst_fh;
612 } else { 610 } else {
613 $grp->result (-1); 611 $grp->result (-1);
614 close $src_fh; 612 close $src_fh;
615 close $dst_fh; 613 close $dst_fh;
616 614
617 aioreq $pri; 615 aioreq $pri;
618 add $grp aio_unlink $dst; 616 add $grp aio_unlink $dst;
619 }
620 }; 617 }
621 } else {
622 $grp->result (-1);
623 } 618 };
619 } else {
620 $grp->result (-1);
624 }, 621 }
625
626 } else {
627 $grp->result (-1);
628 } 622 },
623
624 } else {
625 $grp->result (-1);
629 }; 626 }
630
631 $grp
632 } 627 };
628
629 $grp
633} 630}
634 631
635=item aio_move $srcpath, $dstpath, $callback->($status) 632=item aio_move $srcpath, $dstpath, $callback->($status)
636 633
637Try to move the I<file> (directories not supported as either source or 634Try to move the I<file> (directories not supported as either source or
638destination) from C<$srcpath> to C<$dstpath> and call the callback with 635destination) from C<$srcpath> to C<$dstpath> and call the callback with
639the C<0> (error) or C<-1> ok. 636the C<0> (error) or C<-1> ok.
640 637
641This is a composite request that tries to rename(2) the file first. If 638This 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 639rename fails with C<EXDEV>, it copies the file with C<aio_copy> and, if
643that is successful, unlinking the C<$srcpath>. 640that is successful, unlinks the C<$srcpath>.
644 641
645=cut 642=cut
646 643
647sub aio_move($$;$) { 644sub aio_move($$;$) {
648 aio_block {
649 my ($src, $dst, $cb) = @_; 645 my ($src, $dst, $cb) = @_;
650 646
651 my $pri = aioreq_pri; 647 my $pri = aioreq_pri;
652 my $grp = aio_group $cb; 648 my $grp = aio_group $cb;
653 649
654 aioreq_pri $pri; 650 aioreq_pri $pri;
655 add $grp aio_rename $src, $dst, sub { 651 add $grp aio_rename $src, $dst, sub {
656 if ($_[0] && $! == EXDEV) { 652 if ($_[0] && $! == EXDEV) {
657 aioreq_pri $pri; 653 aioreq_pri $pri;
658 add $grp aio_copy $src, $dst, sub { 654 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]); 655 $grp->result ($_[0]);
656
657 if (!$_[0]) {
658 aioreq_pri $pri;
659 add $grp aio_unlink $src;
660 }
668 } 661 };
662 } else {
663 $grp->result ($_[0]);
669 }; 664 }
670
671 $grp
672 } 665 };
666
667 $grp
673} 668}
674 669
675=item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs) 670=item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs)
676 671
677Scans a directory (similar to C<aio_readdir>) but additionally tries to 672Scans a directory (similar to C<aio_readdir>) but additionally tries to
… …
725directory counting heuristic. 720directory counting heuristic.
726 721
727=cut 722=cut
728 723
729sub aio_scandir($$;$) { 724sub aio_scandir($$;$) {
730 aio_block {
731 my ($path, $maxreq, $cb) = @_; 725 my ($path, $maxreq, $cb) = @_;
732 726
733 my $pri = aioreq_pri; 727 my $pri = aioreq_pri;
734 728
735 my $grp = aio_group $cb; 729 my $grp = aio_group $cb;
736 730
737 $maxreq = 4 if $maxreq <= 0; 731 $maxreq = 4 if $maxreq <= 0;
738 732
739 # stat once 733 # stat once
734 aioreq_pri $pri;
735 add $grp aio_stat $path, sub {
736 return $grp->result () if $_[0];
737 my $now = time;
738 my $hash1 = join ":", (stat _)[0,1,3,7,9];
739
740 # read the directory entries
740 aioreq_pri $pri; 741 aioreq_pri $pri;
741 add $grp aio_stat $path, sub { 742 add $grp aio_readdir $path, sub {
743 my $entries = shift
742 return $grp->result () if $_[0]; 744 or return $grp->result ();
743 my $now = time;
744 my $hash1 = join ":", (stat _)[0,1,3,7,9];
745 745
746 # read the directory entries 746 # stat the dir another time
747 aioreq_pri $pri; 747 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 { 748 add $grp aio_stat $path, sub {
755 my $hash2 = join ":", (stat _)[0,1,3,7,9]; 749 my $hash2 = join ":", (stat _)[0,1,3,7,9];
756 750
757 my $ndirs; 751 my $ndirs;
758 752
759 # take the slow route if anything looks fishy 753 # take the slow route if anything looks fishy
760 if ($hash1 ne $hash2 or (stat _)[9] == $now) { 754 if ($hash1 ne $hash2 or (stat _)[9] == $now) {
761 $ndirs = -1; 755 $ndirs = -1;
762 } else { 756 } else {
763 # if nlink == 2, we are finished 757 # if nlink == 2, we are finished
764 # on non-posix-fs's, we rely on nlink < 2 758 # on non-posix-fs's, we rely on nlink < 2
765 $ndirs = (stat _)[3] - 2 759 $ndirs = (stat _)[3] - 2
766 or return $grp->result ([], $entries); 760 or return $grp->result ([], $entries);
767 } 761 }
768 762
769 # sort into likely dirs and likely nondirs 763 # sort into likely dirs and likely nondirs
770 # dirs == files without ".", short entries first 764 # dirs == files without ".", short entries first
771 $entries = [map $_->[0], 765 $entries = [map $_->[0],
772 sort { $b->[1] cmp $a->[1] } 766 sort { $b->[1] cmp $a->[1] }
773 map [$_, sprintf "%s%04d", (/.\./ ? "1" : "0"), length], 767 map [$_, sprintf "%s%04d", (/.\./ ? "1" : "0"), length],
774 @$entries]; 768 @$entries];
775 769
776 my (@dirs, @nondirs); 770 my (@dirs, @nondirs);
777 771
778 my $statgrp = add $grp aio_group sub { 772 my $statgrp = add $grp aio_group sub {
779 $grp->result (\@dirs, \@nondirs); 773 $grp->result (\@dirs, \@nondirs);
780 }; 774 };
781 775
782 limit $statgrp $maxreq; 776 limit $statgrp $maxreq;
783 feed $statgrp sub { 777 feed $statgrp sub {
784 return unless @$entries; 778 return unless @$entries;
785 my $entry = pop @$entries; 779 my $entry = pop @$entries;
786 780
787 aioreq_pri $pri; 781 aioreq_pri $pri;
788 add $statgrp aio_stat "$path/$entry/.", sub { 782 add $statgrp aio_stat "$path/$entry/.", sub {
789 if ($_[0] < 0) { 783 if ($_[0] < 0) {
790 push @nondirs, $entry; 784 push @nondirs, $entry;
791 } else { 785 } else {
792 # need to check for real directory 786 # need to check for real directory
793 aioreq_pri $pri; 787 aioreq_pri $pri;
794 add $statgrp aio_lstat "$path/$entry", sub { 788 add $statgrp aio_lstat "$path/$entry", sub {
795 if (-d _) { 789 if (-d _) {
796 push @dirs, $entry; 790 push @dirs, $entry;
797 791
798 unless (--$ndirs) { 792 unless (--$ndirs) {
799 push @nondirs, @$entries; 793 push @nondirs, @$entries;
800 feed $statgrp; 794 feed $statgrp;
801 }
802 } else {
803 push @nondirs, $entry;
804 } 795 }
796 } else {
797 push @nondirs, $entry;
805 } 798 }
806 } 799 }
807 }; 800 }
808 }; 801 };
809 }; 802 };
810 }; 803 };
811 }; 804 };
812
813 $grp
814 } 805 };
806
807 $grp
815} 808}
816 809
817=item aio_rmtree $path, $callback->($status) 810=item aio_rmtree $path, $callback->($status)
818 811
819Delete a directory tree starting (and including) C<$path>, return the 812Delete a directory tree starting (and including) C<$path>, return the
… …
823 816
824=cut 817=cut
825 818
826sub aio_rmtree; 819sub aio_rmtree;
827sub aio_rmtree($;$) { 820sub aio_rmtree($;$) {
828 aio_block {
829 my ($path, $cb) = @_; 821 my ($path, $cb) = @_;
830 822
831 my $pri = aioreq_pri; 823 my $pri = aioreq_pri;
832 my $grp = aio_group $cb; 824 my $grp = aio_group $cb;
833 825
834 aioreq_pri $pri; 826 aioreq_pri $pri;
835 add $grp aio_scandir $path, 0, sub { 827 add $grp aio_scandir $path, 0, sub {
836 my ($dirs, $nondirs) = @_; 828 my ($dirs, $nondirs) = @_;
837 829
838 my $dirgrp = aio_group sub { 830 my $dirgrp = aio_group sub {
839 add $grp aio_rmdir $path, sub { 831 add $grp aio_rmdir $path, sub {
840 $grp->result ($_[0]); 832 $grp->result ($_[0]);
841 };
842 }; 833 };
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 }; 834 };
849 835
850 $grp 836 (aioreq_pri $pri), add $dirgrp aio_rmtree "$path/$_" for @$dirs;
837 (aioreq_pri $pri), add $dirgrp aio_unlink "$path/$_" for @$nondirs;
838
839 add $grp $dirgrp;
851 } 840 };
841
842 $grp
852} 843}
853 844
854=item aio_sync $callback->($status) 845=item aio_sync $callback->($status)
855 846
856Asynchronously call sync and call the callback when finished. 847Asynchronously call sync and call the callback when finished.
… …
866callback with the fdatasync result code. 857callback with the fdatasync result code.
867 858
868If this call isn't available because your OS lacks it or it couldn't be 859If 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. 860detected, it will be emulated by calling C<fsync> instead.
870 861
862=item aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status)
863
864Sync the data portion of the file specified by C<$offset> and C<$length>
865to disk (but NOT the metadata), by calling the Linux-specific
866sync_file_range call. If sync_file_range is not available or it returns
867ENOSYS, then fdatasync or fsync is being substituted.
868
869C<$flags> can be a combination of C<IO::AIO::SYNC_FILE_RANGE_WAIT_BEFORE>,
870C<IO::AIO::SYNC_FILE_RANGE_WRITE> and
871C<IO::AIO::SYNC_FILE_RANGE_WAIT_AFTER>: refer to the sync_file_range
872manpage for details.
873
871=item aio_pathsync $path, $callback->($status) 874=item aio_pathsync $path, $callback->($status)
872 875
873This request tries to open, fsync and close the given path. This is a 876This request tries to open, fsync and close the given path. This is a
874composite request intended tosync directories after directory operations 877composite request intended to sync directories after directory operations
875(E.g. rename). This might not work on all operating systems or have any 878(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 879specific effect, but usually it makes sure that directory changes get
877written to disc. It works for anything that can be opened for read-only, 880written to disc. It works for anything that can be opened for read-only,
878not just directories. 881not just directories.
879 882
880Passes C<0> when everything went ok, and C<-1> on error. 883Passes C<0> when everything went ok, and C<-1> on error.
881 884
882=cut 885=cut
883 886
884sub aio_pathsync($;$) { 887sub aio_pathsync($;$) {
885 aio_block {
886 my ($path, $cb) = @_; 888 my ($path, $cb) = @_;
887 889
888 my $pri = aioreq_pri; 890 my $pri = aioreq_pri;
889 my $grp = aio_group $cb; 891 my $grp = aio_group $cb;
890 892
891 aioreq_pri $pri; 893 aioreq_pri $pri;
892 add $grp aio_open $path, O_RDONLY, 0, sub { 894 add $grp aio_open $path, O_RDONLY, 0, sub {
893 my ($fh) = @_; 895 my ($fh) = @_;
894 if ($fh) { 896 if ($fh) {
897 aioreq_pri $pri;
898 add $grp aio_fsync $fh, sub {
899 $grp->result ($_[0]);
900
895 aioreq_pri $pri; 901 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; 902 add $grp aio_close $fh;
901 };
902 } else {
903 $grp->result (-1);
904 } 903 };
904 } else {
905 $grp->result (-1);
905 }; 906 }
906
907 $grp
908 } 907 };
908
909 $grp
909} 910}
910 911
911=item aio_group $callback->(...) 912=item aio_group $callback->(...)
912 913
913This is a very special aio request: Instead of doing something, it is a 914This is a very special aio request: Instead of doing something, it is a
… …
1026Their lifetime, simplified, looks like this: when they are empty, they 1027Their lifetime, simplified, looks like this: when they are empty, they
1027will finish very quickly. If they contain only requests that are in the 1028will finish very quickly. If they contain only requests that are in the
1028C<done> state, they will also finish. Otherwise they will continue to 1029C<done> state, they will also finish. Otherwise they will continue to
1029exist. 1030exist.
1030 1031
1031That means after creating a group you have some time to add requests. And 1032That 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 1033(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 1034the C<poll_cb>). And in the callbacks of those requests, you can add
1034itself finish. 1035further requests to the group. And only when all those requests have
1036finished will the the group itself finish.
1035 1037
1036=over 4 1038=over 4
1037 1039
1038=item add $grp ... 1040=item add $grp ...
1039 1041
… …
1072=item feed $grp $callback->($grp) 1074=item feed $grp $callback->($grp)
1073 1075
1074Sets a feeder/generator on this group: every group can have an attached 1076Sets a feeder/generator on this group: every group can have an attached
1075generator that generates requests if idle. The idea behind this is that, 1077generator 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, 1078although you could just queue as many requests as you want in a group,
1077this might starve other requests for a potentially long time. For 1079this might starve other requests for a potentially long time. For example,
1078example, C<aio_scandir> might generate hundreds of thousands C<aio_stat> 1080C<aio_scandir> might generate hundreds of thousands C<aio_stat> requests,
1079requests, delaying any later requests for a long time. 1081delaying any later requests for a long time.
1080 1082
1081To avoid this, and allow incremental generation of requests, you can 1083To avoid this, and allow incremental generation of requests, you can
1082instead a group and set a feeder on it that generates those requests. The 1084instead 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>, 1085feed 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 1086below) requests active in the group itself and is expected to queue more
… …
1088not impose any limits). 1090not impose any limits).
1089 1091
1090If the feed does not queue more requests when called, it will be 1092If the feed does not queue more requests when called, it will be
1091automatically removed from the group. 1093automatically removed from the group.
1092 1094
1093If the feed limit is C<0>, it will be set to C<2> automatically. 1095If the feed limit is C<0> when this method is called, it will be set to
1096C<2> automatically.
1094 1097
1095Example: 1098Example:
1096 1099
1097 # stat all files in @files, but only ever use four aio requests concurrently: 1100 # stat all files in @files, but only ever use four aio requests concurrently:
1098 1101
… …
1110Sets the feeder limit for the group: The feeder will be called whenever 1113Sets the feeder limit for the group: The feeder will be called whenever
1111the group contains less than this many requests. 1114the group contains less than this many requests.
1112 1115
1113Setting the limit to C<0> will pause the feeding process. 1116Setting the limit to C<0> will pause the feeding process.
1114 1117
1118The default value for the limit is C<0>, but note that setting a feeder
1119automatically bumps it up to C<2>.
1120
1115=back 1121=back
1116 1122
1117=head2 SUPPORT FUNCTIONS 1123=head2 SUPPORT FUNCTIONS
1118 1124
1119=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION 1125=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION
… …
1130See C<poll_cb> for an example. 1136See C<poll_cb> for an example.
1131 1137
1132=item IO::AIO::poll_cb 1138=item IO::AIO::poll_cb
1133 1139
1134Process some outstanding events on the result pipe. You have to call this 1140Process some outstanding events on the result pipe. You have to call this
1135regularly. Returns the number of events processed. Returns immediately 1141regularly. Returns C<0> if all events could be processed, or C<-1> if it
1142returned earlier for whatever reason. Returns immediately when no events
1136when no events are outstanding. The amount of events processed depends on 1143are 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>. 1144C<IO::AIO::max_poll_req> and C<IO::AIO::max_poll_time>.
1138 1145
1139If not all requests were processed for whatever reason, the filehandle 1146If not all requests were processed for whatever reason, the filehandle
1140will still be ready when C<poll_cb> returns. 1147will still be ready when C<poll_cb> returns, so normally you don't have to
1148do anything special to have it called later.
1141 1149
1142Example: Install an Event watcher that automatically calls 1150Example: Install an Event watcher that automatically calls
1143IO::AIO::poll_cb with high priority: 1151IO::AIO::poll_cb with high priority:
1144 1152
1145 Event->io (fd => IO::AIO::poll_fileno, 1153 Event->io (fd => IO::AIO::poll_fileno,
… …
1259 1267
1260The default is probably ok in most situations, especially if thread 1268The default is probably ok in most situations, especially if thread
1261creation is fast. If thread creation is very slow on your system you might 1269creation is fast. If thread creation is very slow on your system you might
1262want to use larger values. 1270want to use larger values.
1263 1271
1264=item $oldmaxreqs = IO::AIO::max_outstanding $maxreqs 1272=item IO::AIO::max_outstanding $maxreqs
1265 1273
1266This is a very bad function to use in interactive programs because it 1274This 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 1275blocks, and a bad way to reduce concurrency because it is inexact: Better
1268use an C<aio_group> together with a feed callback. 1276use an C<aio_group> together with a feed callback.
1269 1277
… …
1274 1282
1275The default value is very large, so there is no practical limit on the 1283The default value is very large, so there is no practical limit on the
1276number of outstanding requests. 1284number of outstanding requests.
1277 1285
1278You can still queue as many requests as you want. Therefore, 1286You can still queue as many requests as you want. Therefore,
1279C<max_oustsanding> is mainly useful in simple scripts (with low values) or 1287C<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). 1288as a stop gap to shield against fatal memory overflow (with large values).
1281 1289
1282=back 1290=back
1283 1291
1284=head3 STATISTICAL INFORMATION 1292=head3 STATISTICAL INFORMATION
… …
1354 1362
1355Known bugs will be fixed in the next release. 1363Known bugs will be fixed in the next release.
1356 1364
1357=head1 SEE ALSO 1365=head1 SEE ALSO
1358 1366
1359L<Coro::AIO>. 1367L<AnyEvent::AIO> for easy integration into event loops, L<Coro::AIO> for a
1368more natural syntax.
1360 1369
1361=head1 AUTHOR 1370=head1 AUTHOR
1362 1371
1363 Marc Lehmann <schmorp@schmorp.de> 1372 Marc Lehmann <schmorp@schmorp.de>
1364 http://home.schmorp.de/ 1373 http://home.schmorp.de/

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