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Comparing IO-AIO/AIO.pm (file contents):
Revision 1.120 by root, Sun Dec 2 21:51:36 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, 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 = '2.6'; 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
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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
… …
322 321
323Asynchronously close a file and call the callback with the result 322Asynchronously close a file and call the callback with the result
324code. 323code.
325 324
326Unfortunately, you can't do this to perl. Perl I<insists> very strongly on 325Unfortunately, you can't do this to perl. Perl I<insists> very strongly on
327closing the file descriptor associated with the filehandle itself. Here is 326closing the file descriptor associated with the filehandle itself.
328what aio_close will try:
329 327
330 1. dup()licate the fd 328Therefore, C<aio_close> will not close the filehandle - instead it will
331 2. asynchronously close() the duplicated fd 329use dup2 to overwrite the file descriptor with the write-end of a pipe
332 3. dup()licate the fd once more 330(the pipe fd will be created on demand and will be cached).
333 4. let perl close() the filehandle
334 5. asynchronously close the duplicated fd
335 331
336The idea is that the first close() flushes stuff to disk that closing an 332Or in other words: the file descriptor will be closed, but it will not be
337fd will flush, so when perl closes the fd, nothing much will need to be 333free for reuse until the perl filehandle is closed.
338flushed. The second async. close() will then flush stuff to disk that
339closing the last fd to the file will flush.
340
341Just FYI, SuSv3 has this to say on close:
342
343 All outstanding record locks owned by the process on the file
344 associated with the file descriptor shall be removed.
345
346 If fildes refers to a socket, close() shall cause the socket to be
347 destroyed. ... close() shall block for up to the current linger
348 interval until all data is transmitted.
349 [this actually sounds like a specification bug, but who knows]
350
351And at least Linux additionally actually flushes stuff on every close,
352even when the file itself is still open.
353
354Sounds enourmously inefficient and complicated? Yes... please show me how
355to nuke perl's fd out of existence...
356 334
357=cut 335=cut
358
359sub aio_close($;$) {
360 aio_block {
361 my ($fh, $cb) = @_;
362
363 my $pri = aioreq_pri;
364 my $grp = aio_group $cb;
365
366 my $fd = fileno $fh;
367
368 defined $fd or Carp::croak "aio_close called with fd-less filehandle";
369
370 # if the dups fail we will simply get EBADF
371 my $fd2 = _dup $fd;
372 aioreq_pri $pri;
373 add $grp _aio_close $fd2, sub {
374 my $fd2 = _dup $fd;
375 close $fh;
376 aioreq_pri $pri;
377 add $grp _aio_close $fd2, sub {
378 $grp->result ($_[0]);
379 };
380 };
381
382 $grp
383 }
384}
385
386 336
387=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval) 337=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
388 338
389=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval) 339=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
390 340
… …
589memory. Status is the same as with aio_read. 539memory. Status is the same as with aio_read.
590 540
591=cut 541=cut
592 542
593sub aio_load($$;$) { 543sub aio_load($$;$) {
594 aio_block {
595 my ($path, undef, $cb) = @_; 544 my ($path, undef, $cb) = @_;
596 my $data = \$_[1]; 545 my $data = \$_[1];
597 546
598 my $pri = aioreq_pri; 547 my $pri = aioreq_pri;
599 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);
600 554
601 aioreq_pri $pri; 555 aioreq_pri $pri;
602 add $grp aio_open $path, O_RDONLY, 0, sub {
603 my $fh = shift
604 or return $grp->result (-1);
605
606 aioreq_pri $pri;
607 add $grp aio_read $fh, 0, (-s $fh), $$data, 0, sub { 556 add $grp aio_read $fh, 0, (-s $fh), $$data, 0, sub {
608 $grp->result ($_[0]); 557 $grp->result ($_[0]);
609 };
610 }; 558 };
611
612 $grp
613 } 559 };
560
561 $grp
614} 562}
615 563
616=item aio_copy $srcpath, $dstpath, $callback->($status) 564=item aio_copy $srcpath, $dstpath, $callback->($status)
617 565
618Try 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
619destination) from C<$srcpath> to C<$dstpath> and call the callback with 567destination) from C<$srcpath> to C<$dstpath> and call the callback with
620the C<0> (error) or C<-1> ok. 568the C<0> (error) or C<-1> ok.
621 569
622This is a composite request that it creates the destination file with 570This is a composite request that creates the destination file with
623mode 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
624C<aio_sendfile>, followed by restoring atime, mtime, access mode and 572C<aio_sendfile>, followed by restoring atime, mtime, access mode and
625uid/gid, in that order. 573uid/gid, in that order.
626 574
627If an error occurs, the partial destination file will be unlinked, if 575If an error occurs, the partial destination file will be unlinked, if
… …
629errors are being ignored. 577errors are being ignored.
630 578
631=cut 579=cut
632 580
633sub aio_copy($$;$) { 581sub aio_copy($$;$) {
634 aio_block {
635 my ($src, $dst, $cb) = @_; 582 my ($src, $dst, $cb) = @_;
636 583
637 my $pri = aioreq_pri; 584 my $pri = aioreq_pri;
638 my $grp = aio_group $cb; 585 my $grp = aio_group $cb;
639 586
640 aioreq_pri $pri; 587 aioreq_pri $pri;
641 add $grp aio_open $src, O_RDONLY, 0, sub { 588 add $grp aio_open $src, O_RDONLY, 0, sub {
642 if (my $src_fh = $_[0]) { 589 if (my $src_fh = $_[0]) {
643 my @stat = stat $src_fh; 590 my @stat = stat $src_fh;
644 591
645 aioreq_pri $pri; 592 aioreq_pri $pri;
646 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 {
647 if (my $dst_fh = $_[0]) { 594 if (my $dst_fh = $_[0]) {
648 aioreq_pri $pri; 595 aioreq_pri $pri;
649 add $grp aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub { 596 add $grp aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub {
650 if ($_[0] == $stat[7]) { 597 if ($_[0] == $stat[7]) {
651 $grp->result (0); 598 $grp->result (0);
652 close $src_fh; 599 close $src_fh;
653 600
654 # those should not normally block. should. should. 601 # those should not normally block. should. should.
655 utime $stat[8], $stat[9], $dst; 602 utime $stat[8], $stat[9], $dst;
656 chmod $stat[2] & 07777, $dst_fh; 603 chmod $stat[2] & 07777, $dst_fh;
657 chown $stat[4], $stat[5], $dst_fh; 604 chown $stat[4], $stat[5], $dst_fh;
658 605
659 aioreq_pri $pri; 606 aioreq_pri $pri;
660 add $grp aio_close $dst_fh; 607 add $grp aio_close $dst_fh;
661 } else { 608 } else {
662 $grp->result (-1); 609 $grp->result (-1);
663 close $src_fh; 610 close $src_fh;
664 close $dst_fh; 611 close $dst_fh;
665 612
666 aioreq $pri; 613 aioreq $pri;
667 add $grp aio_unlink $dst; 614 add $grp aio_unlink $dst;
668 }
669 }; 615 }
670 } else {
671 $grp->result (-1);
672 } 616 };
617 } else {
618 $grp->result (-1);
673 }, 619 }
674
675 } else {
676 $grp->result (-1);
677 } 620 },
621
622 } else {
623 $grp->result (-1);
678 }; 624 }
679
680 $grp
681 } 625 };
626
627 $grp
682} 628}
683 629
684=item aio_move $srcpath, $dstpath, $callback->($status) 630=item aio_move $srcpath, $dstpath, $callback->($status)
685 631
686Try 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
687destination) from C<$srcpath> to C<$dstpath> and call the callback with 633destination) from C<$srcpath> to C<$dstpath> and call the callback with
688the C<0> (error) or C<-1> ok. 634the C<0> (error) or C<-1> ok.
689 635
690This 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
691rename 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
692that is successful, unlinking the C<$srcpath>. 638that is successful, unlinks the C<$srcpath>.
693 639
694=cut 640=cut
695 641
696sub aio_move($$;$) { 642sub aio_move($$;$) {
697 aio_block {
698 my ($src, $dst, $cb) = @_; 643 my ($src, $dst, $cb) = @_;
699 644
700 my $pri = aioreq_pri; 645 my $pri = aioreq_pri;
701 my $grp = aio_group $cb; 646 my $grp = aio_group $cb;
702 647
703 aioreq_pri $pri; 648 aioreq_pri $pri;
704 add $grp aio_rename $src, $dst, sub { 649 add $grp aio_rename $src, $dst, sub {
705 if ($_[0] && $! == EXDEV) { 650 if ($_[0] && $! == EXDEV) {
706 aioreq_pri $pri; 651 aioreq_pri $pri;
707 add $grp aio_copy $src, $dst, sub { 652 add $grp aio_copy $src, $dst, sub {
708 $grp->result ($_[0]);
709
710 if (!$_[0]) {
711 aioreq_pri $pri;
712 add $grp aio_unlink $src;
713 }
714 };
715 } else {
716 $grp->result ($_[0]); 653 $grp->result ($_[0]);
654
655 if (!$_[0]) {
656 aioreq_pri $pri;
657 add $grp aio_unlink $src;
658 }
717 } 659 };
660 } else {
661 $grp->result ($_[0]);
718 }; 662 }
719
720 $grp
721 } 663 };
664
665 $grp
722} 666}
723 667
724=item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs) 668=item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs)
725 669
726Scans a directory (similar to C<aio_readdir>) but additionally tries to 670Scans a directory (similar to C<aio_readdir>) but additionally tries to
… …
774directory counting heuristic. 718directory counting heuristic.
775 719
776=cut 720=cut
777 721
778sub aio_scandir($$;$) { 722sub aio_scandir($$;$) {
779 aio_block {
780 my ($path, $maxreq, $cb) = @_; 723 my ($path, $maxreq, $cb) = @_;
781 724
782 my $pri = aioreq_pri; 725 my $pri = aioreq_pri;
783 726
784 my $grp = aio_group $cb; 727 my $grp = aio_group $cb;
785 728
786 $maxreq = 4 if $maxreq <= 0; 729 $maxreq = 4 if $maxreq <= 0;
787 730
788 # 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
789 aioreq_pri $pri; 739 aioreq_pri $pri;
790 add $grp aio_stat $path, sub { 740 add $grp aio_readdir $path, sub {
741 my $entries = shift
791 return $grp->result () if $_[0]; 742 or return $grp->result ();
792 my $now = time;
793 my $hash1 = join ":", (stat _)[0,1,3,7,9];
794 743
795 # read the directory entries 744 # stat the dir another time
796 aioreq_pri $pri; 745 aioreq_pri $pri;
797 add $grp aio_readdir $path, sub {
798 my $entries = shift
799 or return $grp->result ();
800
801 # stat the dir another time
802 aioreq_pri $pri;
803 add $grp aio_stat $path, sub { 746 add $grp aio_stat $path, sub {
804 my $hash2 = join ":", (stat _)[0,1,3,7,9]; 747 my $hash2 = join ":", (stat _)[0,1,3,7,9];
805 748
806 my $ndirs; 749 my $ndirs;
807 750
808 # take the slow route if anything looks fishy 751 # take the slow route if anything looks fishy
809 if ($hash1 ne $hash2 or (stat _)[9] == $now) { 752 if ($hash1 ne $hash2 or (stat _)[9] == $now) {
810 $ndirs = -1; 753 $ndirs = -1;
811 } else { 754 } else {
812 # if nlink == 2, we are finished 755 # if nlink == 2, we are finished
813 # on non-posix-fs's, we rely on nlink < 2 756 # on non-posix-fs's, we rely on nlink < 2
814 $ndirs = (stat _)[3] - 2 757 $ndirs = (stat _)[3] - 2
815 or return $grp->result ([], $entries); 758 or return $grp->result ([], $entries);
816 } 759 }
817 760
818 # sort into likely dirs and likely nondirs 761 # sort into likely dirs and likely nondirs
819 # dirs == files without ".", short entries first 762 # dirs == files without ".", short entries first
820 $entries = [map $_->[0], 763 $entries = [map $_->[0],
821 sort { $b->[1] cmp $a->[1] } 764 sort { $b->[1] cmp $a->[1] }
822 map [$_, sprintf "%s%04d", (/.\./ ? "1" : "0"), length], 765 map [$_, sprintf "%s%04d", (/.\./ ? "1" : "0"), length],
823 @$entries]; 766 @$entries];
824 767
825 my (@dirs, @nondirs); 768 my (@dirs, @nondirs);
826 769
827 my $statgrp = add $grp aio_group sub { 770 my $statgrp = add $grp aio_group sub {
828 $grp->result (\@dirs, \@nondirs); 771 $grp->result (\@dirs, \@nondirs);
829 }; 772 };
830 773
831 limit $statgrp $maxreq; 774 limit $statgrp $maxreq;
832 feed $statgrp sub { 775 feed $statgrp sub {
833 return unless @$entries; 776 return unless @$entries;
834 my $entry = pop @$entries; 777 my $entry = pop @$entries;
835 778
836 aioreq_pri $pri; 779 aioreq_pri $pri;
837 add $statgrp aio_stat "$path/$entry/.", sub { 780 add $statgrp aio_stat "$path/$entry/.", sub {
838 if ($_[0] < 0) { 781 if ($_[0] < 0) {
839 push @nondirs, $entry; 782 push @nondirs, $entry;
840 } else { 783 } else {
841 # need to check for real directory 784 # need to check for real directory
842 aioreq_pri $pri; 785 aioreq_pri $pri;
843 add $statgrp aio_lstat "$path/$entry", sub { 786 add $statgrp aio_lstat "$path/$entry", sub {
844 if (-d _) { 787 if (-d _) {
845 push @dirs, $entry; 788 push @dirs, $entry;
846 789
847 unless (--$ndirs) { 790 unless (--$ndirs) {
848 push @nondirs, @$entries; 791 push @nondirs, @$entries;
849 feed $statgrp; 792 feed $statgrp;
850 }
851 } else {
852 push @nondirs, $entry;
853 } 793 }
794 } else {
795 push @nondirs, $entry;
854 } 796 }
855 } 797 }
856 }; 798 }
857 }; 799 };
858 }; 800 };
859 }; 801 };
860 }; 802 };
861
862 $grp
863 } 803 };
804
805 $grp
864} 806}
865 807
866=item aio_rmtree $path, $callback->($status) 808=item aio_rmtree $path, $callback->($status)
867 809
868Delete a directory tree starting (and including) C<$path>, return the 810Delete a directory tree starting (and including) C<$path>, return the
… …
872 814
873=cut 815=cut
874 816
875sub aio_rmtree; 817sub aio_rmtree;
876sub aio_rmtree($;$) { 818sub aio_rmtree($;$) {
877 aio_block {
878 my ($path, $cb) = @_; 819 my ($path, $cb) = @_;
879 820
880 my $pri = aioreq_pri; 821 my $pri = aioreq_pri;
881 my $grp = aio_group $cb; 822 my $grp = aio_group $cb;
882 823
883 aioreq_pri $pri; 824 aioreq_pri $pri;
884 add $grp aio_scandir $path, 0, sub { 825 add $grp aio_scandir $path, 0, sub {
885 my ($dirs, $nondirs) = @_; 826 my ($dirs, $nondirs) = @_;
886 827
887 my $dirgrp = aio_group sub { 828 my $dirgrp = aio_group sub {
888 add $grp aio_rmdir $path, sub { 829 add $grp aio_rmdir $path, sub {
889 $grp->result ($_[0]); 830 $grp->result ($_[0]);
890 };
891 }; 831 };
892
893 (aioreq_pri $pri), add $dirgrp aio_rmtree "$path/$_" for @$dirs;
894 (aioreq_pri $pri), add $dirgrp aio_unlink "$path/$_" for @$nondirs;
895
896 add $grp $dirgrp;
897 }; 832 };
898 833
899 $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;
900 } 838 };
839
840 $grp
901} 841}
902 842
903=item aio_sync $callback->($status) 843=item aio_sync $callback->($status)
904 844
905Asynchronously call sync and call the callback when finished. 845Asynchronously call sync and call the callback when finished.
… …
915callback with the fdatasync result code. 855callback with the fdatasync result code.
916 856
917If 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
918detected, it will be emulated by calling C<fsync> instead. 858detected, it will be emulated by calling C<fsync> instead.
919 859
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
920=item aio_pathsync $path, $callback->($status) 872=item aio_pathsync $path, $callback->($status)
921 873
922This 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
923composite request intended tosync directories after directory operations 875composite request intended to sync directories after directory operations
924(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
925specific effect, but usually it makes sure that directory changes get 877specific effect, but usually it makes sure that directory changes get
926written 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,
927not just directories. 879not just directories.
928 880
929Passes C<0> when everything went ok, and C<-1> on error. 881Passes C<0> when everything went ok, and C<-1> on error.
930 882
931=cut 883=cut
932 884
933sub aio_pathsync($;$) { 885sub aio_pathsync($;$) {
934 aio_block {
935 my ($path, $cb) = @_; 886 my ($path, $cb) = @_;
936 887
937 my $pri = aioreq_pri; 888 my $pri = aioreq_pri;
938 my $grp = aio_group $cb; 889 my $grp = aio_group $cb;
939 890
940 aioreq_pri $pri; 891 aioreq_pri $pri;
941 add $grp aio_open $path, O_RDONLY, 0, sub { 892 add $grp aio_open $path, O_RDONLY, 0, sub {
942 my ($fh) = @_; 893 my ($fh) = @_;
943 if ($fh) { 894 if ($fh) {
895 aioreq_pri $pri;
896 add $grp aio_fsync $fh, sub {
897 $grp->result ($_[0]);
898
944 aioreq_pri $pri; 899 aioreq_pri $pri;
945 add $grp aio_fsync $fh, sub {
946 $grp->result ($_[0]);
947
948 aioreq_pri $pri;
949 add $grp aio_close $fh; 900 add $grp aio_close $fh;
950 };
951 } else {
952 $grp->result (-1);
953 } 901 };
902 } else {
903 $grp->result (-1);
954 }; 904 }
955
956 $grp
957 } 905 };
906
907 $grp
958} 908}
959 909
960=item aio_group $callback->(...) 910=item aio_group $callback->(...)
961 911
962This 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
… …
1075Their lifetime, simplified, looks like this: when they are empty, they 1025Their lifetime, simplified, looks like this: when they are empty, they
1076will 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
1077C<done> state, they will also finish. Otherwise they will continue to 1027C<done> state, they will also finish. Otherwise they will continue to
1078exist. 1028exist.
1079 1029
1080That 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
1081in 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
1082group. 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
1083itself finish. 1033further requests to the group. And only when all those requests have
1034finished will the the group itself finish.
1084 1035
1085=over 4 1036=over 4
1086 1037
1087=item add $grp ... 1038=item add $grp ...
1088 1039
… …
1121=item feed $grp $callback->($grp) 1072=item feed $grp $callback->($grp)
1122 1073
1123Sets 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
1124generator that generates requests if idle. The idea behind this is that, 1075generator that generates requests if idle. The idea behind this is that,
1125although 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,
1126this might starve other requests for a potentially long time. For 1077this might starve other requests for a potentially long time. For example,
1127example, C<aio_scandir> might generate hundreds of thousands C<aio_stat> 1078C<aio_scandir> might generate hundreds of thousands C<aio_stat> requests,
1128requests, delaying any later requests for a long time. 1079delaying any later requests for a long time.
1129 1080
1130To avoid this, and allow incremental generation of requests, you can 1081To avoid this, and allow incremental generation of requests, you can
1131instead 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
1132feed 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>,
1133below) 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
… …
1137not impose any limits). 1088not impose any limits).
1138 1089
1139If 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
1140automatically removed from the group. 1091automatically removed from the group.
1141 1092
1142If 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.
1143 1095
1144Example: 1096Example:
1145 1097
1146 # 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:
1147 1099
… …
1159Sets 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
1160the group contains less than this many requests. 1112the group contains less than this many requests.
1161 1113
1162Setting the limit to C<0> will pause the feeding process. 1114Setting the limit to C<0> will pause the feeding process.
1163 1115
1116The default value for the limit is C<0>, but note that setting a feeder
1117automatically bumps it up to C<2>.
1118
1164=back 1119=back
1165 1120
1166=head2 SUPPORT FUNCTIONS 1121=head2 SUPPORT FUNCTIONS
1167 1122
1168=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION 1123=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION
… …
1179See C<poll_cb> for an example. 1134See C<poll_cb> for an example.
1180 1135
1181=item IO::AIO::poll_cb 1136=item IO::AIO::poll_cb
1182 1137
1183Process 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
1184regularly. 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
1185when no events are outstanding. The amount of events processed depends on 1141are outstanding. The amount of events processed depends on the settings of
1186the 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>.
1187 1143
1188If not all requests were processed for whatever reason, the filehandle 1144If not all requests were processed for whatever reason, the filehandle
1189will 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.
1190 1147
1191Example: Install an Event watcher that automatically calls 1148Example: Install an Event watcher that automatically calls
1192IO::AIO::poll_cb with high priority: 1149IO::AIO::poll_cb with high priority:
1193 1150
1194 Event->io (fd => IO::AIO::poll_fileno, 1151 Event->io (fd => IO::AIO::poll_fileno,
… …
1308 1265
1309The default is probably ok in most situations, especially if thread 1266The default is probably ok in most situations, especially if thread
1310creation 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
1311want to use larger values. 1268want to use larger values.
1312 1269
1313=item $oldmaxreqs = IO::AIO::max_outstanding $maxreqs 1270=item IO::AIO::max_outstanding $maxreqs
1314 1271
1315This 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
1316blocks, 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
1317use an C<aio_group> together with a feed callback. 1274use an C<aio_group> together with a feed callback.
1318 1275
… …
1323 1280
1324The 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
1325number of outstanding requests. 1282number of outstanding requests.
1326 1283
1327You can still queue as many requests as you want. Therefore, 1284You can still queue as many requests as you want. Therefore,
1328C<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
1329as 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).
1330 1287
1331=back 1288=back
1332 1289
1333=head3 STATISTICAL INFORMATION 1290=head3 STATISTICAL INFORMATION
… …
1403 1360
1404Known bugs will be fixed in the next release. 1361Known bugs will be fixed in the next release.
1405 1362
1406=head1 SEE ALSO 1363=head1 SEE ALSO
1407 1364
1408L<Coro::AIO>. 1365L<AnyEvent::AIO> for easy integration into event loops, L<Coro::AIO> for a
1366more natural syntax.
1409 1367
1410=head1 AUTHOR 1368=head1 AUTHOR
1411 1369
1412 Marc Lehmann <schmorp@schmorp.de> 1370 Marc Lehmann <schmorp@schmorp.de>
1413 http://home.schmorp.de/ 1371 http://home.schmorp.de/

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