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Comparing IO-AIO/AIO.pm (file contents):
Revision 1.116 by root, Wed Oct 3 21:27:51 2007 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, POE, urxvt, pureperl...)
32 use AnyEvent::AIO;
33
31 # AnyEvent integration 34 # EV integration
32 open my $fh, "<&=" . IO::AIO::poll_fileno or die "$!"; 35 my $w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb;
33 my $w = AnyEvent->io (fh => $fh, poll => 'r', cb => sub { IO::AIO::poll_cb });
34 36
35 # Event integration 37 # Event integration
36 Event->io (fd => IO::AIO::poll_fileno, 38 Event->io (fd => IO::AIO::poll_fileno,
37 poll => 'r', 39 poll => 'r',
38 cb => \&IO::AIO::poll_cb); 40 cb => \&IO::AIO::poll_cb);
… …
183 185
184=cut 186=cut
185 187
186package IO::AIO; 188package IO::AIO;
187 189
190use Carp ();
191
188no warnings; 192no warnings;
189use strict 'vars'; 193use strict 'vars';
190 194
191use base 'Exporter'; 195use base 'Exporter';
192 196
193BEGIN { 197BEGIN {
194 our $VERSION = '2.5'; 198 our $VERSION = '3.16';
195 199
196 our @AIO_REQ = qw(aio_sendfile aio_read aio_write aio_open aio_close aio_stat 200 our @AIO_REQ = qw(aio_sendfile aio_read aio_write aio_open aio_close
197 aio_lstat aio_unlink aio_rmdir aio_readdir aio_scandir aio_symlink 201 aio_stat aio_lstat aio_unlink aio_rmdir aio_readdir
198 aio_readlink aio_fsync aio_fdatasync aio_readahead aio_rename aio_link 202 aio_scandir aio_symlink aio_readlink aio_sync aio_fsync
203 aio_fdatasync aio_sync_file_range aio_pathsync aio_readahead
204 aio_rename aio_link aio_move aio_copy aio_group
199 aio_move aio_copy aio_group aio_nop aio_mknod aio_load aio_rmtree aio_mkdir 205 aio_nop aio_mknod aio_load aio_rmtree aio_mkdir aio_chown
200 aio_chown aio_chmod aio_utime aio_truncate); 206 aio_chmod aio_utime aio_truncate);
207
201 our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice aio_block)); 208 our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice));
202 our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush 209 our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush
203 min_parallel max_parallel max_idle 210 min_parallel max_parallel max_idle
204 nreqs nready npending nthreads 211 nreqs nready npending nthreads
205 max_poll_time max_poll_reqs); 212 max_poll_time max_poll_reqs);
206 213
… …
217All the C<aio_*> calls are more or less thin wrappers around the syscall 224All the C<aio_*> calls are more or less thin wrappers around the syscall
218with the same name (sans C<aio_>). The arguments are similar or identical, 225with the same name (sans C<aio_>). The arguments are similar or identical,
219and they all accept an additional (and optional) C<$callback> argument 226and they all accept an additional (and optional) C<$callback> argument
220which 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
221the 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
222perl, which usually delivers "false") as it's sole argument when the given 229perl, which usually delivers "false") as its sole argument after the given
223syscall has been executed asynchronously. 230syscall has been executed asynchronously.
224 231
225All functions expecting a filehandle keep a copy of the filehandle 232All functions expecting a filehandle keep a copy of the filehandle
226internally until the request has finished. 233internally until the request has finished.
227 234
… …
241your 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
242environment, d) use Glib::filename_from_unicode on unicode filenames or e) 249environment, d) use Glib::filename_from_unicode on unicode filenames or e)
243use something else to ensure your scalar has the correct contents. 250use something else to ensure your scalar has the correct contents.
244 251
245This 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
246handles correctly wether it is set or not. 253handles correctly whether it is set or not.
247 254
248=over 4 255=over 4
249 256
250=item $prev_pri = aioreq_pri [$pri] 257=item $prev_pri = aioreq_pri [$pri]
251 258
… …
313=item aio_close $fh, $callback->($status) 320=item aio_close $fh, $callback->($status)
314 321
315Asynchronously close a file and call the callback with the result 322Asynchronously close a file and call the callback with the result
316code. 323code.
317 324
318Unlike the other functions operating on files, this function uses the 325Unfortunately, you can't do this to perl. Perl I<insists> very strongly on
319PerlIO layer to close the filehandle. The reason is that the PerlIO API 326closing the file descriptor associated with the filehandle itself.
320insists on closing the underlying fd itself, no matter what, and doesn't
321allow modifications to the fd. Unfortunately, it is not clear that you can
322call PerlIO from different threads (actually, its quite clear that this
323won't work in some cases), so while it likely works perfectly with simple
324file handles (such as the ones created by C<aio_open>) it might fail in
325interesting ways for others.
326 327
327Having said that, aio_close tries to clean up the filehandle as much as 328Therefore, C<aio_close> will not close the filehandle - instead it will
328possible before handing it to an io thread, and generally does work. 329use dup2 to overwrite the file descriptor with the write-end of a pipe
330(the pipe fd will be created on demand and will be cached).
329 331
332Or in other words: the file descriptor will be closed, but it will not be
333free for reuse until the perl filehandle is closed.
334
335=cut
330 336
331=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval) 337=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
332 338
333=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval) 339=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
334 340
… …
533memory. Status is the same as with aio_read. 539memory. Status is the same as with aio_read.
534 540
535=cut 541=cut
536 542
537sub aio_load($$;$) { 543sub aio_load($$;$) {
538 aio_block {
539 my ($path, undef, $cb) = @_; 544 my ($path, undef, $cb) = @_;
540 my $data = \$_[1]; 545 my $data = \$_[1];
541 546
542 my $pri = aioreq_pri; 547 my $pri = aioreq_pri;
543 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);
544 554
545 aioreq_pri $pri; 555 aioreq_pri $pri;
546 add $grp aio_open $path, O_RDONLY, 0, sub {
547 my $fh = shift
548 or return $grp->result (-1);
549
550 aioreq_pri $pri;
551 add $grp aio_read $fh, 0, (-s $fh), $$data, 0, sub { 556 add $grp aio_read $fh, 0, (-s $fh), $$data, 0, sub {
552 $grp->result ($_[0]); 557 $grp->result ($_[0]);
553 };
554 }; 558 };
555
556 $grp
557 } 559 };
560
561 $grp
558} 562}
559 563
560=item aio_copy $srcpath, $dstpath, $callback->($status) 564=item aio_copy $srcpath, $dstpath, $callback->($status)
561 565
562Try 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
563destination) from C<$srcpath> to C<$dstpath> and call the callback with 567destination) from C<$srcpath> to C<$dstpath> and call the callback with
564the C<0> (error) or C<-1> ok. 568the C<0> (error) or C<-1> ok.
565 569
566This is a composite request that it creates the destination file with 570This is a composite request that creates the destination file with
567mode 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
568C<aio_sendfile>, followed by restoring atime, mtime, access mode and 572C<aio_sendfile>, followed by restoring atime, mtime, access mode and
569uid/gid, in that order. 573uid/gid, in that order.
570 574
571If an error occurs, the partial destination file will be unlinked, if 575If an error occurs, the partial destination file will be unlinked, if
… …
573errors are being ignored. 577errors are being ignored.
574 578
575=cut 579=cut
576 580
577sub aio_copy($$;$) { 581sub aio_copy($$;$) {
578 aio_block {
579 my ($src, $dst, $cb) = @_; 582 my ($src, $dst, $cb) = @_;
580 583
581 my $pri = aioreq_pri; 584 my $pri = aioreq_pri;
582 my $grp = aio_group $cb; 585 my $grp = aio_group $cb;
583 586
584 aioreq_pri $pri; 587 aioreq_pri $pri;
585 add $grp aio_open $src, O_RDONLY, 0, sub { 588 add $grp aio_open $src, O_RDONLY, 0, sub {
586 if (my $src_fh = $_[0]) { 589 if (my $src_fh = $_[0]) {
587 my @stat = stat $src_fh; 590 my @stat = stat $src_fh;
588 591
589 aioreq_pri $pri; 592 aioreq_pri $pri;
590 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 {
591 if (my $dst_fh = $_[0]) { 594 if (my $dst_fh = $_[0]) {
592 aioreq_pri $pri; 595 aioreq_pri $pri;
593 add $grp aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub { 596 add $grp aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub {
594 if ($_[0] == $stat[7]) { 597 if ($_[0] == $stat[7]) {
595 $grp->result (0); 598 $grp->result (0);
596 close $src_fh; 599 close $src_fh;
597 600
598 # those should not normally block. should. should. 601 # those should not normally block. should. should.
599 utime $stat[8], $stat[9], $dst; 602 utime $stat[8], $stat[9], $dst;
600 chmod $stat[2] & 07777, $dst_fh; 603 chmod $stat[2] & 07777, $dst_fh;
601 chown $stat[4], $stat[5], $dst_fh; 604 chown $stat[4], $stat[5], $dst_fh;
605
606 aioreq_pri $pri;
602 close $dst_fh; 607 add $grp aio_close $dst_fh;
603 } else { 608 } else {
604 $grp->result (-1); 609 $grp->result (-1);
605 close $src_fh; 610 close $src_fh;
606 close $dst_fh; 611 close $dst_fh;
607 612
608 aioreq $pri; 613 aioreq $pri;
609 add $grp aio_unlink $dst; 614 add $grp aio_unlink $dst;
610 }
611 }; 615 }
612 } else {
613 $grp->result (-1);
614 } 616 };
617 } else {
618 $grp->result (-1);
615 }, 619 }
616
617 } else {
618 $grp->result (-1);
619 } 620 },
621
622 } else {
623 $grp->result (-1);
620 }; 624 }
621
622 $grp
623 } 625 };
626
627 $grp
624} 628}
625 629
626=item aio_move $srcpath, $dstpath, $callback->($status) 630=item aio_move $srcpath, $dstpath, $callback->($status)
627 631
628Try 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
629destination) from C<$srcpath> to C<$dstpath> and call the callback with 633destination) from C<$srcpath> to C<$dstpath> and call the callback with
630the C<0> (error) or C<-1> ok. 634the C<0> (error) or C<-1> ok.
631 635
632This 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
633rename 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
634that is successful, unlinking the C<$srcpath>. 638that is successful, unlinks the C<$srcpath>.
635 639
636=cut 640=cut
637 641
638sub aio_move($$;$) { 642sub aio_move($$;$) {
639 aio_block {
640 my ($src, $dst, $cb) = @_; 643 my ($src, $dst, $cb) = @_;
641 644
642 my $pri = aioreq_pri; 645 my $pri = aioreq_pri;
643 my $grp = aio_group $cb; 646 my $grp = aio_group $cb;
644 647
645 aioreq_pri $pri; 648 aioreq_pri $pri;
646 add $grp aio_rename $src, $dst, sub { 649 add $grp aio_rename $src, $dst, sub {
647 if ($_[0] && $! == EXDEV) { 650 if ($_[0] && $! == EXDEV) {
648 aioreq_pri $pri; 651 aioreq_pri $pri;
649 add $grp aio_copy $src, $dst, sub { 652 add $grp aio_copy $src, $dst, sub {
650 $grp->result ($_[0]);
651
652 if (!$_[0]) {
653 aioreq_pri $pri;
654 add $grp aio_unlink $src;
655 }
656 };
657 } else {
658 $grp->result ($_[0]); 653 $grp->result ($_[0]);
654
655 if (!$_[0]) {
656 aioreq_pri $pri;
657 add $grp aio_unlink $src;
658 }
659 } 659 };
660 } else {
661 $grp->result ($_[0]);
660 }; 662 }
661
662 $grp
663 } 663 };
664
665 $grp
664} 666}
665 667
666=item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs) 668=item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs)
667 669
668Scans a directory (similar to C<aio_readdir>) but additionally tries to 670Scans a directory (similar to C<aio_readdir>) but additionally tries to
… …
716directory counting heuristic. 718directory counting heuristic.
717 719
718=cut 720=cut
719 721
720sub aio_scandir($$;$) { 722sub aio_scandir($$;$) {
721 aio_block {
722 my ($path, $maxreq, $cb) = @_; 723 my ($path, $maxreq, $cb) = @_;
723 724
724 my $pri = aioreq_pri; 725 my $pri = aioreq_pri;
725 726
726 my $grp = aio_group $cb; 727 my $grp = aio_group $cb;
727 728
728 $maxreq = 4 if $maxreq <= 0; 729 $maxreq = 4 if $maxreq <= 0;
729 730
730 # 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
731 aioreq_pri $pri; 739 aioreq_pri $pri;
732 add $grp aio_stat $path, sub { 740 add $grp aio_readdir $path, sub {
741 my $entries = shift
733 return $grp->result () if $_[0]; 742 or return $grp->result ();
734 my $now = time;
735 my $hash1 = join ":", (stat _)[0,1,3,7,9];
736 743
737 # read the directory entries 744 # stat the dir another time
738 aioreq_pri $pri; 745 aioreq_pri $pri;
739 add $grp aio_readdir $path, sub {
740 my $entries = shift
741 or return $grp->result ();
742
743 # stat the dir another time
744 aioreq_pri $pri;
745 add $grp aio_stat $path, sub { 746 add $grp aio_stat $path, sub {
746 my $hash2 = join ":", (stat _)[0,1,3,7,9]; 747 my $hash2 = join ":", (stat _)[0,1,3,7,9];
747 748
748 my $ndirs; 749 my $ndirs;
749 750
750 # take the slow route if anything looks fishy 751 # take the slow route if anything looks fishy
751 if ($hash1 ne $hash2 or (stat _)[9] == $now) { 752 if ($hash1 ne $hash2 or (stat _)[9] == $now) {
752 $ndirs = -1; 753 $ndirs = -1;
753 } else { 754 } else {
754 # if nlink == 2, we are finished 755 # if nlink == 2, we are finished
755 # on non-posix-fs's, we rely on nlink < 2 756 # on non-posix-fs's, we rely on nlink < 2
756 $ndirs = (stat _)[3] - 2 757 $ndirs = (stat _)[3] - 2
757 or return $grp->result ([], $entries); 758 or return $grp->result ([], $entries);
758 } 759 }
759 760
760 # sort into likely dirs and likely nondirs 761 # sort into likely dirs and likely nondirs
761 # dirs == files without ".", short entries first 762 # dirs == files without ".", short entries first
762 $entries = [map $_->[0], 763 $entries = [map $_->[0],
763 sort { $b->[1] cmp $a->[1] } 764 sort { $b->[1] cmp $a->[1] }
764 map [$_, sprintf "%s%04d", (/.\./ ? "1" : "0"), length], 765 map [$_, sprintf "%s%04d", (/.\./ ? "1" : "0"), length],
765 @$entries]; 766 @$entries];
766 767
767 my (@dirs, @nondirs); 768 my (@dirs, @nondirs);
768 769
769 my $statgrp = add $grp aio_group sub { 770 my $statgrp = add $grp aio_group sub {
770 $grp->result (\@dirs, \@nondirs); 771 $grp->result (\@dirs, \@nondirs);
771 }; 772 };
772 773
773 limit $statgrp $maxreq; 774 limit $statgrp $maxreq;
774 feed $statgrp sub { 775 feed $statgrp sub {
775 return unless @$entries; 776 return unless @$entries;
776 my $entry = pop @$entries; 777 my $entry = pop @$entries;
777 778
778 aioreq_pri $pri; 779 aioreq_pri $pri;
779 add $statgrp aio_stat "$path/$entry/.", sub { 780 add $statgrp aio_stat "$path/$entry/.", sub {
780 if ($_[0] < 0) { 781 if ($_[0] < 0) {
781 push @nondirs, $entry; 782 push @nondirs, $entry;
782 } else { 783 } else {
783 # need to check for real directory 784 # need to check for real directory
784 aioreq_pri $pri; 785 aioreq_pri $pri;
785 add $statgrp aio_lstat "$path/$entry", sub { 786 add $statgrp aio_lstat "$path/$entry", sub {
786 if (-d _) { 787 if (-d _) {
787 push @dirs, $entry; 788 push @dirs, $entry;
788 789
789 unless (--$ndirs) { 790 unless (--$ndirs) {
790 push @nondirs, @$entries; 791 push @nondirs, @$entries;
791 feed $statgrp; 792 feed $statgrp;
792 }
793 } else {
794 push @nondirs, $entry;
795 } 793 }
794 } else {
795 push @nondirs, $entry;
796 } 796 }
797 } 797 }
798 }; 798 }
799 }; 799 };
800 }; 800 };
801 }; 801 };
802 }; 802 };
803
804 $grp
805 } 803 };
804
805 $grp
806} 806}
807 807
808=item aio_rmtree $path, $callback->($status) 808=item aio_rmtree $path, $callback->($status)
809 809
810Delete a directory tree starting (and including) C<$path>, return the 810Delete a directory tree starting (and including) C<$path>, return the
… …
814 814
815=cut 815=cut
816 816
817sub aio_rmtree; 817sub aio_rmtree;
818sub aio_rmtree($;$) { 818sub aio_rmtree($;$) {
819 aio_block {
820 my ($path, $cb) = @_; 819 my ($path, $cb) = @_;
821 820
822 my $pri = aioreq_pri; 821 my $pri = aioreq_pri;
823 my $grp = aio_group $cb; 822 my $grp = aio_group $cb;
824 823
825 aioreq_pri $pri; 824 aioreq_pri $pri;
826 add $grp aio_scandir $path, 0, sub { 825 add $grp aio_scandir $path, 0, sub {
827 my ($dirs, $nondirs) = @_; 826 my ($dirs, $nondirs) = @_;
828 827
829 my $dirgrp = aio_group sub { 828 my $dirgrp = aio_group sub {
830 add $grp aio_rmdir $path, sub { 829 add $grp aio_rmdir $path, sub {
831 $grp->result ($_[0]); 830 $grp->result ($_[0]);
832 };
833 }; 831 };
834
835 (aioreq_pri $pri), add $dirgrp aio_rmtree "$path/$_" for @$dirs;
836 (aioreq_pri $pri), add $dirgrp aio_unlink "$path/$_" for @$nondirs;
837
838 add $grp $dirgrp;
839 }; 832 };
840 833
841 $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;
842 } 838 };
839
840 $grp
843} 841}
842
843=item aio_sync $callback->($status)
844
845Asynchronously call sync and call the callback when finished.
844 846
845=item aio_fsync $fh, $callback->($status) 847=item aio_fsync $fh, $callback->($status)
846 848
847Asynchronously call fsync on the given filehandle and call the callback 849Asynchronously call fsync on the given filehandle and call the callback
848with the fsync result code. 850with the fsync result code.
… …
852Asynchronously call fdatasync on the given filehandle and call the 854Asynchronously call fdatasync on the given filehandle and call the
853callback with the fdatasync result code. 855callback with the fdatasync result code.
854 856
855If 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
856detected, it will be emulated by calling C<fsync> instead. 858detected, it will be emulated by calling C<fsync> instead.
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
872=item aio_pathsync $path, $callback->($status)
873
874This request tries to open, fsync and close the given path. This is a
875composite request intended to sync directories after directory operations
876(E.g. rename). This might not work on all operating systems or have any
877specific effect, but usually it makes sure that directory changes get
878written to disc. It works for anything that can be opened for read-only,
879not just directories.
880
881Passes C<0> when everything went ok, and C<-1> on error.
882
883=cut
884
885sub aio_pathsync($;$) {
886 my ($path, $cb) = @_;
887
888 my $pri = aioreq_pri;
889 my $grp = aio_group $cb;
890
891 aioreq_pri $pri;
892 add $grp aio_open $path, O_RDONLY, 0, sub {
893 my ($fh) = @_;
894 if ($fh) {
895 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;
901 };
902 } else {
903 $grp->result (-1);
904 }
905 };
906
907 $grp
908}
857 909
858=item aio_group $callback->(...) 910=item aio_group $callback->(...)
859 911
860This 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
861container for other aio requests, which is useful if you want to bundle 913container for other aio requests, which is useful if you want to bundle
… …
973Their lifetime, simplified, looks like this: when they are empty, they 1025Their lifetime, simplified, looks like this: when they are empty, they
974will 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
975C<done> state, they will also finish. Otherwise they will continue to 1027C<done> state, they will also finish. Otherwise they will continue to
976exist. 1028exist.
977 1029
978That 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
979in 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
980group. 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
981itself finish. 1033further requests to the group. And only when all those requests have
1034finished will the the group itself finish.
982 1035
983=over 4 1036=over 4
984 1037
985=item add $grp ... 1038=item add $grp ...
986 1039
… …
998itself. Useful when you queued a lot of events but got a result early. 1051itself. Useful when you queued a lot of events but got a result early.
999 1052
1000=item $grp->result (...) 1053=item $grp->result (...)
1001 1054
1002Set the result value(s) that will be passed to the group callback when all 1055Set the result value(s) that will be passed to the group callback when all
1003subrequests have finished and set thre groups errno to the current value 1056subrequests have finished and set the groups errno to the current value
1004of errno (just like calling C<errno> without an error number). By default, 1057of errno (just like calling C<errno> without an error number). By default,
1005no argument will be passed and errno is zero. 1058no argument will be passed and errno is zero.
1006 1059
1007=item $grp->errno ([$errno]) 1060=item $grp->errno ([$errno])
1008 1061
… …
1019=item feed $grp $callback->($grp) 1072=item feed $grp $callback->($grp)
1020 1073
1021Sets 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
1022generator that generates requests if idle. The idea behind this is that, 1075generator that generates requests if idle. The idea behind this is that,
1023although 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,
1024this might starve other requests for a potentially long time. For 1077this might starve other requests for a potentially long time. For example,
1025example, C<aio_scandir> might generate hundreds of thousands C<aio_stat> 1078C<aio_scandir> might generate hundreds of thousands C<aio_stat> requests,
1026requests, delaying any later requests for a long time. 1079delaying any later requests for a long time.
1027 1080
1028To avoid this, and allow incremental generation of requests, you can 1081To avoid this, and allow incremental generation of requests, you can
1029instead 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
1030feed 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>,
1031below) 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
… …
1035not impose any limits). 1088not impose any limits).
1036 1089
1037If 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
1038automatically removed from the group. 1091automatically removed from the group.
1039 1092
1040If 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.
1041 1095
1042Example: 1096Example:
1043 1097
1044 # 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:
1045 1099
… …
1057Sets 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
1058the group contains less than this many requests. 1112the group contains less than this many requests.
1059 1113
1060Setting the limit to C<0> will pause the feeding process. 1114Setting the limit to C<0> will pause the feeding process.
1061 1115
1116The default value for the limit is C<0>, but note that setting a feeder
1117automatically bumps it up to C<2>.
1118
1062=back 1119=back
1063 1120
1064=head2 SUPPORT FUNCTIONS 1121=head2 SUPPORT FUNCTIONS
1065 1122
1066=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION 1123=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION
… …
1077See C<poll_cb> for an example. 1134See C<poll_cb> for an example.
1078 1135
1079=item IO::AIO::poll_cb 1136=item IO::AIO::poll_cb
1080 1137
1081Process 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
1082regularly. 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
1083when no events are outstanding. The amount of events processed depends on 1141are outstanding. The amount of events processed depends on the settings of
1084the 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>.
1085 1143
1086If not all requests were processed for whatever reason, the filehandle 1144If not all requests were processed for whatever reason, the filehandle
1087will 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.
1088 1147
1089Example: Install an Event watcher that automatically calls 1148Example: Install an Event watcher that automatically calls
1090IO::AIO::poll_cb with high priority: 1149IO::AIO::poll_cb with high priority:
1091 1150
1092 Event->io (fd => IO::AIO::poll_fileno, 1151 Event->io (fd => IO::AIO::poll_fileno,
… …
1206 1265
1207The default is probably ok in most situations, especially if thread 1266The default is probably ok in most situations, especially if thread
1208creation 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
1209want to use larger values. 1268want to use larger values.
1210 1269
1211=item $oldmaxreqs = IO::AIO::max_outstanding $maxreqs 1270=item IO::AIO::max_outstanding $maxreqs
1212 1271
1213This 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
1214blocks, 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
1215use an C<aio_group> together with a feed callback. 1274use an C<aio_group> together with a feed callback.
1216 1275
… …
1221 1280
1222The 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
1223number of outstanding requests. 1282number of outstanding requests.
1224 1283
1225You can still queue as many requests as you want. Therefore, 1284You can still queue as many requests as you want. Therefore,
1226C<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
1227as 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).
1228 1287
1229=back 1288=back
1230 1289
1231=head3 STATISTICAL INFORMATION 1290=head3 STATISTICAL INFORMATION
… …
1301 1360
1302Known bugs will be fixed in the next release. 1361Known bugs will be fixed in the next release.
1303 1362
1304=head1 SEE ALSO 1363=head1 SEE ALSO
1305 1364
1306L<Coro::AIO>. 1365L<AnyEvent::AIO> for easy integration into event loops, L<Coro::AIO> for a
1366more natural syntax.
1307 1367
1308=head1 AUTHOR 1368=head1 AUTHOR
1309 1369
1310 Marc Lehmann <schmorp@schmorp.de> 1370 Marc Lehmann <schmorp@schmorp.de>
1311 http://home.schmorp.de/ 1371 http://home.schmorp.de/

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