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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 1.143 by root, Thu Nov 20 09:01:40 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 = '3.17';
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);
213
214 push @AIO_REQ, qw(aio_busy); # not exported
206 215
207 @IO::AIO::GRP::ISA = 'IO::AIO::REQ'; 216 @IO::AIO::GRP::ISA = 'IO::AIO::REQ';
208 217
209 require XSLoader; 218 require XSLoader;
210 XSLoader::load ("IO::AIO", $VERSION); 219 XSLoader::load ("IO::AIO", $VERSION);
217All the C<aio_*> calls are more or less thin wrappers around the syscall 226All the C<aio_*> calls are more or less thin wrappers around the syscall
218with the same name (sans C<aio_>). The arguments are similar or identical, 227with the same name (sans C<aio_>). The arguments are similar or identical,
219and they all accept an additional (and optional) C<$callback> argument 228and they all accept an additional (and optional) C<$callback> argument
220which 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
221the 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
222perl, which usually delivers "false") as it's sole argument when the given 231perl, which usually delivers "false") as its sole argument after the given
223syscall has been executed asynchronously. 232syscall has been executed asynchronously.
224 233
225All functions expecting a filehandle keep a copy of the filehandle 234All functions expecting a filehandle keep a copy of the filehandle
226internally until the request has finished. 235internally until the request has finished.
227 236
241your 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
242environment, d) use Glib::filename_from_unicode on unicode filenames or e) 251environment, d) use Glib::filename_from_unicode on unicode filenames or e)
243use something else to ensure your scalar has the correct contents. 252use something else to ensure your scalar has the correct contents.
244 253
245This 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
246handles correctly wether it is set or not. 255handles correctly whether it is set or not.
247 256
248=over 4 257=over 4
249 258
250=item $prev_pri = aioreq_pri [$pri] 259=item $prev_pri = aioreq_pri [$pri]
251 260
313=item aio_close $fh, $callback->($status) 322=item aio_close $fh, $callback->($status)
314 323
315Asynchronously close a file and call the callback with the result 324Asynchronously close a file and call the callback with the result
316code. 325code.
317 326
318Unlike the other functions operating on files, this function uses the 327Unfortunately, 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 328closing 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.
326 329
327Having said that, aio_close tries to clean up the filehandle as much as 330Therefore, C<aio_close> will not close the filehandle - instead it will
328possible before handing it to an io thread, and generally does work. 331use dup2 to overwrite the file descriptor with the write-end of a pipe
332(the pipe fd will be created on demand and will be cached).
329 333
334Or in other words: the file descriptor will be closed, but it will not be
335free for reuse until the perl filehandle is closed.
336
337=cut
330 338
331=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval) 339=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
332 340
333=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval) 341=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
334 342
533memory. Status is the same as with aio_read. 541memory. Status is the same as with aio_read.
534 542
535=cut 543=cut
536 544
537sub aio_load($$;$) { 545sub aio_load($$;$) {
538 aio_block {
539 my ($path, undef, $cb) = @_; 546 my ($path, undef, $cb) = @_;
540 my $data = \$_[1]; 547 my $data = \$_[1];
541 548
542 my $pri = aioreq_pri; 549 my $pri = aioreq_pri;
543 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);
544 556
545 aioreq_pri $pri; 557 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), $$data, 0, sub { 558 add $grp aio_read $fh, 0, (-s $fh), $$data, 0, sub {
552 $grp->result ($_[0]); 559 $grp->result ($_[0]);
553 };
554 }; 560 };
555
556 $grp
557 } 561 };
562
563 $grp
558} 564}
559 565
560=item aio_copy $srcpath, $dstpath, $callback->($status) 566=item aio_copy $srcpath, $dstpath, $callback->($status)
561 567
562Try 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
563destination) from C<$srcpath> to C<$dstpath> and call the callback with 569destination) from C<$srcpath> to C<$dstpath> and call the callback with
564the C<0> (error) or C<-1> ok. 570the C<0> (error) or C<-1> ok.
565 571
566This is a composite request that it creates the destination file with 572This is a composite request that creates the destination file with
567mode 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
568C<aio_sendfile>, followed by restoring atime, mtime, access mode and 574C<aio_sendfile>, followed by restoring atime, mtime, access mode and
569uid/gid, in that order. 575uid/gid, in that order.
570 576
571If an error occurs, the partial destination file will be unlinked, if 577If an error occurs, the partial destination file will be unlinked, if
573errors are being ignored. 579errors are being ignored.
574 580
575=cut 581=cut
576 582
577sub aio_copy($$;$) { 583sub aio_copy($$;$) {
578 aio_block {
579 my ($src, $dst, $cb) = @_; 584 my ($src, $dst, $cb) = @_;
580 585
581 my $pri = aioreq_pri; 586 my $pri = aioreq_pri;
582 my $grp = aio_group $cb; 587 my $grp = aio_group $cb;
583 588
584 aioreq_pri $pri; 589 aioreq_pri $pri;
585 add $grp aio_open $src, O_RDONLY, 0, sub { 590 add $grp aio_open $src, O_RDONLY, 0, sub {
586 if (my $src_fh = $_[0]) { 591 if (my $src_fh = $_[0]) {
587 my @stat = stat $src_fh; 592 my @stat = stat $src_fh;
588 593
589 aioreq_pri $pri; 594 aioreq_pri $pri;
590 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 {
591 if (my $dst_fh = $_[0]) { 596 if (my $dst_fh = $_[0]) {
592 aioreq_pri $pri; 597 aioreq_pri $pri;
593 add $grp aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub { 598 add $grp aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub {
594 if ($_[0] == $stat[7]) { 599 if ($_[0] == $stat[7]) {
595 $grp->result (0); 600 $grp->result (0);
596 close $src_fh; 601 close $src_fh;
597 602
598 # those should not normally block. should. should. 603 # those should not normally block. should. should.
599 utime $stat[8], $stat[9], $dst; 604 utime $stat[8], $stat[9], $dst;
600 chmod $stat[2] & 07777, $dst_fh; 605 chmod $stat[2] & 07777, $dst_fh;
601 chown $stat[4], $stat[5], $dst_fh; 606 chown $stat[4], $stat[5], $dst_fh;
607
608 aioreq_pri $pri;
602 close $dst_fh; 609 add $grp aio_close $dst_fh;
603 } else { 610 } else {
604 $grp->result (-1); 611 $grp->result (-1);
605 close $src_fh; 612 close $src_fh;
606 close $dst_fh; 613 close $dst_fh;
607 614
608 aioreq $pri; 615 aioreq $pri;
609 add $grp aio_unlink $dst; 616 add $grp aio_unlink $dst;
610 }
611 }; 617 }
612 } else {
613 $grp->result (-1);
614 } 618 };
619 } else {
620 $grp->result (-1);
615 }, 621 }
616
617 } else {
618 $grp->result (-1);
619 } 622 },
623
624 } else {
625 $grp->result (-1);
620 }; 626 }
621
622 $grp
623 } 627 };
628
629 $grp
624} 630}
625 631
626=item aio_move $srcpath, $dstpath, $callback->($status) 632=item aio_move $srcpath, $dstpath, $callback->($status)
627 633
628Try 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
629destination) from C<$srcpath> to C<$dstpath> and call the callback with 635destination) from C<$srcpath> to C<$dstpath> and call the callback with
630the C<0> (error) or C<-1> ok. 636the C<0> (error) or C<-1> ok.
631 637
632This 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
633rename 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
634that is successful, unlinking the C<$srcpath>. 640that is successful, unlinks the C<$srcpath>.
635 641
636=cut 642=cut
637 643
638sub aio_move($$;$) { 644sub aio_move($$;$) {
639 aio_block {
640 my ($src, $dst, $cb) = @_; 645 my ($src, $dst, $cb) = @_;
641 646
642 my $pri = aioreq_pri; 647 my $pri = aioreq_pri;
643 my $grp = aio_group $cb; 648 my $grp = aio_group $cb;
644 649
645 aioreq_pri $pri; 650 aioreq_pri $pri;
646 add $grp aio_rename $src, $dst, sub { 651 add $grp aio_rename $src, $dst, sub {
647 if ($_[0] && $! == EXDEV) { 652 if ($_[0] && $! == EXDEV) {
648 aioreq_pri $pri; 653 aioreq_pri $pri;
649 add $grp aio_copy $src, $dst, sub { 654 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]); 655 $grp->result ($_[0]);
656
657 if (!$_[0]) {
658 aioreq_pri $pri;
659 add $grp aio_unlink $src;
660 }
659 } 661 };
662 } else {
663 $grp->result ($_[0]);
660 }; 664 }
661
662 $grp
663 } 665 };
666
667 $grp
664} 668}
665 669
666=item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs) 670=item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs)
667 671
668Scans a directory (similar to C<aio_readdir>) but additionally tries to 672Scans a directory (similar to C<aio_readdir>) but additionally tries to
716directory counting heuristic. 720directory counting heuristic.
717 721
718=cut 722=cut
719 723
720sub aio_scandir($$;$) { 724sub aio_scandir($$;$) {
721 aio_block {
722 my ($path, $maxreq, $cb) = @_; 725 my ($path, $maxreq, $cb) = @_;
723 726
724 my $pri = aioreq_pri; 727 my $pri = aioreq_pri;
725 728
726 my $grp = aio_group $cb; 729 my $grp = aio_group $cb;
727 730
728 $maxreq = 4 if $maxreq <= 0; 731 $maxreq = 4 if $maxreq <= 0;
729 732
730 # 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
731 aioreq_pri $pri; 741 aioreq_pri $pri;
732 add $grp aio_stat $path, sub { 742 add $grp aio_readdir $path, sub {
743 my $entries = shift
733 return $grp->result () if $_[0]; 744 or return $grp->result ();
734 my $now = time;
735 my $hash1 = join ":", (stat _)[0,1,3,7,9];
736 745
737 # read the directory entries 746 # stat the dir another time
738 aioreq_pri $pri; 747 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 { 748 add $grp aio_stat $path, sub {
746 my $hash2 = join ":", (stat _)[0,1,3,7,9]; 749 my $hash2 = join ":", (stat _)[0,1,3,7,9];
747 750
748 my $ndirs; 751 my $ndirs;
749 752
750 # take the slow route if anything looks fishy 753 # take the slow route if anything looks fishy
751 if ($hash1 ne $hash2 or (stat _)[9] == $now) { 754 if ($hash1 ne $hash2 or (stat _)[9] == $now) {
752 $ndirs = -1; 755 $ndirs = -1;
753 } else { 756 } else {
754 # if nlink == 2, we are finished 757 # if nlink == 2, we are finished
755 # on non-posix-fs's, we rely on nlink < 2 758 # on non-posix-fs's, we rely on nlink < 2
756 $ndirs = (stat _)[3] - 2 759 $ndirs = (stat _)[3] - 2
757 or return $grp->result ([], $entries); 760 or return $grp->result ([], $entries);
758 } 761 }
759 762
760 # sort into likely dirs and likely nondirs 763 # sort into likely dirs and likely nondirs
761 # dirs == files without ".", short entries first 764 # dirs == files without ".", short entries first
762 $entries = [map $_->[0], 765 $entries = [map $_->[0],
763 sort { $b->[1] cmp $a->[1] } 766 sort { $b->[1] cmp $a->[1] }
764 map [$_, sprintf "%s%04d", (/.\./ ? "1" : "0"), length], 767 map [$_, sprintf "%s%04d", (/.\./ ? "1" : "0"), length],
765 @$entries]; 768 @$entries];
766 769
767 my (@dirs, @nondirs); 770 my (@dirs, @nondirs);
768 771
769 my $statgrp = add $grp aio_group sub { 772 my $statgrp = add $grp aio_group sub {
770 $grp->result (\@dirs, \@nondirs); 773 $grp->result (\@dirs, \@nondirs);
771 }; 774 };
772 775
773 limit $statgrp $maxreq; 776 limit $statgrp $maxreq;
774 feed $statgrp sub { 777 feed $statgrp sub {
775 return unless @$entries; 778 return unless @$entries;
776 my $entry = pop @$entries; 779 my $entry = pop @$entries;
777 780
778 aioreq_pri $pri; 781 aioreq_pri $pri;
779 add $statgrp aio_stat "$path/$entry/.", sub { 782 add $statgrp aio_stat "$path/$entry/.", sub {
780 if ($_[0] < 0) { 783 if ($_[0] < 0) {
781 push @nondirs, $entry; 784 push @nondirs, $entry;
782 } else { 785 } else {
783 # need to check for real directory 786 # need to check for real directory
784 aioreq_pri $pri; 787 aioreq_pri $pri;
785 add $statgrp aio_lstat "$path/$entry", sub { 788 add $statgrp aio_lstat "$path/$entry", sub {
786 if (-d _) { 789 if (-d _) {
787 push @dirs, $entry; 790 push @dirs, $entry;
788 791
789 unless (--$ndirs) { 792 unless (--$ndirs) {
790 push @nondirs, @$entries; 793 push @nondirs, @$entries;
791 feed $statgrp; 794 feed $statgrp;
792 }
793 } else {
794 push @nondirs, $entry;
795 } 795 }
796 } else {
797 push @nondirs, $entry;
796 } 798 }
797 } 799 }
798 }; 800 }
799 }; 801 };
800 }; 802 };
801 }; 803 };
802 }; 804 };
803
804 $grp
805 } 805 };
806
807 $grp
806} 808}
807 809
808=item aio_rmtree $path, $callback->($status) 810=item aio_rmtree $path, $callback->($status)
809 811
810Delete a directory tree starting (and including) C<$path>, return the 812Delete a directory tree starting (and including) C<$path>, return the
814 816
815=cut 817=cut
816 818
817sub aio_rmtree; 819sub aio_rmtree;
818sub aio_rmtree($;$) { 820sub aio_rmtree($;$) {
819 aio_block {
820 my ($path, $cb) = @_; 821 my ($path, $cb) = @_;
821 822
822 my $pri = aioreq_pri; 823 my $pri = aioreq_pri;
823 my $grp = aio_group $cb; 824 my $grp = aio_group $cb;
824 825
825 aioreq_pri $pri; 826 aioreq_pri $pri;
826 add $grp aio_scandir $path, 0, sub { 827 add $grp aio_scandir $path, 0, sub {
827 my ($dirs, $nondirs) = @_; 828 my ($dirs, $nondirs) = @_;
828 829
829 my $dirgrp = aio_group sub { 830 my $dirgrp = aio_group sub {
830 add $grp aio_rmdir $path, sub { 831 add $grp aio_rmdir $path, sub {
831 $grp->result ($_[0]); 832 $grp->result ($_[0]);
832 };
833 }; 833 };
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 }; 834 };
840 835
841 $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;
842 } 840 };
841
842 $grp
843} 843}
844
845=item aio_sync $callback->($status)
846
847Asynchronously call sync and call the callback when finished.
844 848
845=item aio_fsync $fh, $callback->($status) 849=item aio_fsync $fh, $callback->($status)
846 850
847Asynchronously call fsync on the given filehandle and call the callback 851Asynchronously call fsync on the given filehandle and call the callback
848with the fsync result code. 852with the fsync result code.
852Asynchronously call fdatasync on the given filehandle and call the 856Asynchronously call fdatasync on the given filehandle and call the
853callback with the fdatasync result code. 857callback with the fdatasync result code.
854 858
855If 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
856detected, it will be emulated by calling C<fsync> instead. 860detected, it will be emulated by calling C<fsync> instead.
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
874=item aio_pathsync $path, $callback->($status)
875
876This request tries to open, fsync and close the given path. This is a
877composite request intended to sync directories after directory operations
878(E.g. rename). This might not work on all operating systems or have any
879specific effect, but usually it makes sure that directory changes get
880written to disc. It works for anything that can be opened for read-only,
881not just directories.
882
883Passes C<0> when everything went ok, and C<-1> on error.
884
885=cut
886
887sub aio_pathsync($;$) {
888 my ($path, $cb) = @_;
889
890 my $pri = aioreq_pri;
891 my $grp = aio_group $cb;
892
893 aioreq_pri $pri;
894 add $grp aio_open $path, O_RDONLY, 0, sub {
895 my ($fh) = @_;
896 if ($fh) {
897 aioreq_pri $pri;
898 add $grp aio_fsync $fh, sub {
899 $grp->result ($_[0]);
900
901 aioreq_pri $pri;
902 add $grp aio_close $fh;
903 };
904 } else {
905 $grp->result (-1);
906 }
907 };
908
909 $grp
910}
857 911
858=item aio_group $callback->(...) 912=item aio_group $callback->(...)
859 913
860This 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
861container for other aio requests, which is useful if you want to bundle 915container for other aio requests, which is useful if you want to bundle
973Their lifetime, simplified, looks like this: when they are empty, they 1027Their lifetime, simplified, looks like this: when they are empty, they
974will 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
975C<done> state, they will also finish. Otherwise they will continue to 1029C<done> state, they will also finish. Otherwise they will continue to
976exist. 1030exist.
977 1031
978That 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
979in 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
980group. 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
981itself finish. 1035further requests to the group. And only when all those requests have
1036finished will the the group itself finish.
982 1037
983=over 4 1038=over 4
984 1039
985=item add $grp ... 1040=item add $grp ...
986 1041
998itself. Useful when you queued a lot of events but got a result early. 1053itself. Useful when you queued a lot of events but got a result early.
999 1054
1000=item $grp->result (...) 1055=item $grp->result (...)
1001 1056
1002Set the result value(s) that will be passed to the group callback when all 1057Set 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 1058subrequests have finished and set the groups errno to the current value
1004of errno (just like calling C<errno> without an error number). By default, 1059of errno (just like calling C<errno> without an error number). By default,
1005no argument will be passed and errno is zero. 1060no argument will be passed and errno is zero.
1006 1061
1007=item $grp->errno ([$errno]) 1062=item $grp->errno ([$errno])
1008 1063
1019=item feed $grp $callback->($grp) 1074=item feed $grp $callback->($grp)
1020 1075
1021Sets 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
1022generator that generates requests if idle. The idea behind this is that, 1077generator 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, 1078although you could just queue as many requests as you want in a group,
1024this might starve other requests for a potentially long time. For 1079this might starve other requests for a potentially long time. For example,
1025example, C<aio_scandir> might generate hundreds of thousands C<aio_stat> 1080C<aio_scandir> might generate hundreds of thousands C<aio_stat> requests,
1026requests, delaying any later requests for a long time. 1081delaying any later requests for a long time.
1027 1082
1028To avoid this, and allow incremental generation of requests, you can 1083To avoid this, and allow incremental generation of requests, you can
1029instead 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
1030feed 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>,
1031below) 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
1035not impose any limits). 1090not impose any limits).
1036 1091
1037If 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
1038automatically removed from the group. 1093automatically removed from the group.
1039 1094
1040If 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.
1041 1097
1042Example: 1098Example:
1043 1099
1044 # 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:
1045 1101
1057Sets 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
1058the group contains less than this many requests. 1114the group contains less than this many requests.
1059 1115
1060Setting the limit to C<0> will pause the feeding process. 1116Setting the limit to C<0> will pause the feeding process.
1061 1117
1118The default value for the limit is C<0>, but note that setting a feeder
1119automatically bumps it up to C<2>.
1120
1062=back 1121=back
1063 1122
1064=head2 SUPPORT FUNCTIONS 1123=head2 SUPPORT FUNCTIONS
1065 1124
1066=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION 1125=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION
1077See C<poll_cb> for an example. 1136See C<poll_cb> for an example.
1078 1137
1079=item IO::AIO::poll_cb 1138=item IO::AIO::poll_cb
1080 1139
1081Process 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
1082regularly. 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
1083when no events are outstanding. The amount of events processed depends on 1143are 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>. 1144C<IO::AIO::max_poll_req> and C<IO::AIO::max_poll_time>.
1085 1145
1086If not all requests were processed for whatever reason, the filehandle 1146If not all requests were processed for whatever reason, the filehandle
1087will 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.
1088 1149
1089Example: Install an Event watcher that automatically calls 1150Example: Install an Event watcher that automatically calls
1090IO::AIO::poll_cb with high priority: 1151IO::AIO::poll_cb with high priority:
1091 1152
1092 Event->io (fd => IO::AIO::poll_fileno, 1153 Event->io (fd => IO::AIO::poll_fileno,
1206 1267
1207The default is probably ok in most situations, especially if thread 1268The default is probably ok in most situations, especially if thread
1208creation 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
1209want to use larger values. 1270want to use larger values.
1210 1271
1211=item $oldmaxreqs = IO::AIO::max_outstanding $maxreqs 1272=item IO::AIO::max_outstanding $maxreqs
1212 1273
1213This 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
1214blocks, 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
1215use an C<aio_group> together with a feed callback. 1276use an C<aio_group> together with a feed callback.
1216 1277
1221 1282
1222The 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
1223number of outstanding requests. 1284number of outstanding requests.
1224 1285
1225You can still queue as many requests as you want. Therefore, 1286You can still queue as many requests as you want. Therefore,
1226C<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
1227as 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).
1228 1289
1229=back 1290=back
1230 1291
1231=head3 STATISTICAL INFORMATION 1292=head3 STATISTICAL INFORMATION
1301 1362
1302Known bugs will be fixed in the next release. 1363Known bugs will be fixed in the next release.
1303 1364
1304=head1 SEE ALSO 1365=head1 SEE ALSO
1305 1366
1306L<Coro::AIO>. 1367L<AnyEvent::AIO> for easy integration into event loops, L<Coro::AIO> for a
1368more natural syntax.
1307 1369
1308=head1 AUTHOR 1370=head1 AUTHOR
1309 1371
1310 Marc Lehmann <schmorp@schmorp.de> 1372 Marc Lehmann <schmorp@schmorp.de>
1311 http://home.schmorp.de/ 1373 http://home.schmorp.de/

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