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Revision 1.121 by root, Wed Apr 16 16:45:18 2008 UTC vs.
Revision 1.156 by root, Tue Jun 16 23:41:59 2009 UTC

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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 $aio_w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb;
37 36
38 # Event integration 37 # Event integration
39 Event->io (fd => IO::AIO::poll_fileno, 38 Event->io (fd => IO::AIO::poll_fileno,
40 poll => 'r', 39 poll => 'r',
41 cb => \&IO::AIO::poll_cb); 40 cb => \&IO::AIO::poll_cb);
… …
53 \&IO::AIO::poll_cb); 52 \&IO::AIO::poll_cb);
54 53
55=head1 DESCRIPTION 54=head1 DESCRIPTION
56 55
57This module implements asynchronous I/O using whatever means your 56This module implements asynchronous I/O using whatever means your
58operating system supports. 57operating system supports. It is implemented as an interface to C<libeio>
58(L<http://software.schmorp.de/pkg/libeio.html>).
59 59
60Asynchronous means that operations that can normally block your program 60Asynchronous means that operations that can normally block your program
61(e.g. reading from disk) will be done asynchronously: the operation 61(e.g. reading from disk) will be done asynchronously: the operation
62will still block, but you can do something else in the meantime. This 62will still block, but you can do something else in the meantime. This
63is extremely useful for programs that need to stay interactive even 63is extremely useful for programs that need to stay interactive even
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67on a RAID volume or over NFS when you do a number of stat operations 67on a RAID volume or over NFS when you do a number of stat operations
68concurrently. 68concurrently.
69 69
70While most of this works on all types of file descriptors (for 70While most of this works on all types of file descriptors (for
71example sockets), using these functions on file descriptors that 71example sockets), using these functions on file descriptors that
72support nonblocking operation (again, sockets, pipes etc.) is very 72support nonblocking operation (again, sockets, pipes etc.) is
73inefficient. Use an event loop for that (such as the L<Event|Event> 73very inefficient. Use an event loop for that (such as the L<EV>
74module): IO::AIO will naturally fit into such an event loop itself. 74module): IO::AIO will naturally fit into such an event loop itself.
75 75
76In this version, a number of threads are started that execute your 76In this version, a number of threads are started that execute your
77requests and signal their completion. You don't need thread support 77requests and signal their completion. You don't need thread support
78in perl, and the threads created by this module will not be visible 78in perl, and the threads created by this module will not be visible
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88yourself, always call C<poll_cb> from within the same thread, or never 88yourself, always call C<poll_cb> from within the same thread, or never
89call C<poll_cb> (or other C<aio_> functions) recursively. 89call C<poll_cb> (or other C<aio_> functions) recursively.
90 90
91=head2 EXAMPLE 91=head2 EXAMPLE
92 92
93This is a simple example that uses the Event module and loads 93This is a simple example that uses the EV module and loads
94F</etc/passwd> asynchronously: 94F</etc/passwd> asynchronously:
95 95
96 use Fcntl; 96 use Fcntl;
97 use Event; 97 use EV;
98 use IO::AIO; 98 use IO::AIO;
99 99
100 # register the IO::AIO callback with Event 100 # register the IO::AIO callback with EV
101 Event->io (fd => IO::AIO::poll_fileno, 101 my $aio_w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb;
102 poll => 'r',
103 cb => \&IO::AIO::poll_cb);
104 102
105 # queue the request to open /etc/passwd 103 # queue the request to open /etc/passwd
106 aio_open "/etc/passwd", O_RDONLY, 0, sub { 104 aio_open "/etc/passwd", O_RDONLY, 0, sub {
107 my $fh = shift 105 my $fh = shift
108 or die "error while opening: $!"; 106 or die "error while opening: $!";
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120 118
121 # file contents now in $contents 119 # file contents now in $contents
122 print $contents; 120 print $contents;
123 121
124 # exit event loop and program 122 # exit event loop and program
125 Event::unloop; 123 EV::unloop;
126 }; 124 };
127 }; 125 };
128 126
129 # possibly queue up other requests, or open GUI windows, 127 # possibly queue up other requests, or open GUI windows,
130 # check for sockets etc. etc. 128 # check for sockets etc. etc.
131 129
132 # process events as long as there are some: 130 # process events as long as there are some:
133 Event::loop; 131 EV::loop;
134 132
135=head1 REQUEST ANATOMY AND LIFETIME 133=head1 REQUEST ANATOMY AND LIFETIME
136 134
137Every C<aio_*> function creates a request. which is a C data structure not 135Every C<aio_*> function creates a request. which is a C data structure not
138directly visible to Perl. 136directly visible to Perl.
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194use strict 'vars'; 192use strict 'vars';
195 193
196use base 'Exporter'; 194use base 'Exporter';
197 195
198BEGIN { 196BEGIN {
199 our $VERSION = '2.61'; 197 our $VERSION = '3.23';
200 198
201 our @AIO_REQ = qw(aio_sendfile aio_read aio_write aio_open aio_close 199 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 200 aio_stat aio_lstat aio_unlink aio_rmdir aio_readdir aio_readdirx
203 aio_scandir aio_symlink aio_readlink aio_sync aio_fsync 201 aio_scandir aio_symlink aio_readlink aio_sync aio_fsync
204 aio_fdatasync aio_pathsync aio_readahead 202 aio_fdatasync aio_sync_file_range aio_pathsync aio_readahead
205 aio_rename aio_link aio_move aio_copy aio_group 203 aio_rename aio_link aio_move aio_copy aio_group
206 aio_nop aio_mknod aio_load aio_rmtree aio_mkdir aio_chown 204 aio_nop aio_mknod aio_load aio_rmtree aio_mkdir aio_chown
207 aio_chmod aio_utime aio_truncate); 205 aio_chmod aio_utime aio_truncate);
208 206
209 our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice aio_block)); 207 our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice));
210 our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush 208 our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush
211 min_parallel max_parallel max_idle 209 min_parallel max_parallel max_idle
212 nreqs nready npending nthreads 210 nreqs nready npending nthreads
213 max_poll_time max_poll_reqs); 211 max_poll_time max_poll_reqs);
212
213 push @AIO_REQ, qw(aio_busy); # not exported
214 214
215 @IO::AIO::GRP::ISA = 'IO::AIO::REQ'; 215 @IO::AIO::GRP::ISA = 'IO::AIO::REQ';
216 216
217 require XSLoader; 217 require XSLoader;
218 XSLoader::load ("IO::AIO", $VERSION); 218 XSLoader::load ("IO::AIO", $VERSION);
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225All the C<aio_*> calls are more or less thin wrappers around the syscall 225All the C<aio_*> calls are more or less thin wrappers around the syscall
226with the same name (sans C<aio_>). The arguments are similar or identical, 226with the same name (sans C<aio_>). The arguments are similar or identical,
227and they all accept an additional (and optional) C<$callback> argument 227and they all accept an additional (and optional) C<$callback> argument
228which must be a code reference. This code reference will get called with 228which 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 229the 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 230perl, which usually delivers "false") as its sole argument after the given
231syscall has been executed asynchronously. 231syscall has been executed asynchronously.
232 232
233All functions expecting a filehandle keep a copy of the filehandle 233All functions expecting a filehandle keep a copy of the filehandle
234internally until the request has finished. 234internally until the request has finished.
235 235
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249your pathnames to the locale (or other) encoding in effect in the user 249your pathnames to the locale (or other) encoding in effect in the user
250environment, d) use Glib::filename_from_unicode on unicode filenames or e) 250environment, d) use Glib::filename_from_unicode on unicode filenames or e)
251use something else to ensure your scalar has the correct contents. 251use something else to ensure your scalar has the correct contents.
252 252
253This works, btw. independent of the internal UTF-8 bit, which IO::AIO 253This works, btw. independent of the internal UTF-8 bit, which IO::AIO
254handles correctly wether it is set or not. 254handles correctly whether it is set or not.
255 255
256=over 4 256=over 4
257 257
258=item $prev_pri = aioreq_pri [$pri] 258=item $prev_pri = aioreq_pri [$pri]
259 259
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337 337
338=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval) 338=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
339 339
340=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval) 340=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
341 341
342Reads or writes C<$length> bytes from the specified C<$fh> and C<$offset> 342Reads or writes C<$length> bytes from or to the specified C<$fh> and
343into the scalar given by C<$data> and offset C<$dataoffset> and calls the 343C<$offset> into the scalar given by C<$data> and offset C<$dataoffset>
344callback without the actual number of bytes read (or -1 on error, just 344and calls the callback without the actual number of bytes read (or -1 on
345like the syscall). 345error, just like the syscall).
346
347C<aio_read> will, like C<sysread>, shrink or grow the C<$data> scalar to
348offset plus the actual number of bytes read.
346 349
347If C<$offset> is undefined, then the current file descriptor offset will 350If C<$offset> is undefined, then the current file descriptor offset will
348be used (and updated), otherwise the file descriptor offset will not be 351be used (and updated), otherwise the file descriptor offset will not be
349changed by these calls. 352changed by these calls.
350 353
351If C<$length> is undefined in C<aio_write>, use the remaining length of C<$data>. 354If C<$length> is undefined in C<aio_write>, use the remaining length of
355C<$data>.
352 356
353If C<$dataoffset> is less than zero, it will be counted from the end of 357If C<$dataoffset> is less than zero, it will be counted from the end of
354C<$data>. 358C<$data>.
355 359
356The C<$data> scalar I<MUST NOT> be modified in any way while the request 360The C<$data> scalar I<MUST NOT> be modified in any way while the request
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528 532
529Unlike the POSIX call of the same name, C<aio_readdir> reads an entire 533Unlike the POSIX call of the same name, C<aio_readdir> reads an entire
530directory (i.e. opendir + readdir + closedir). The entries will not be 534directory (i.e. opendir + readdir + closedir). The entries will not be
531sorted, and will B<NOT> include the C<.> and C<..> entries. 535sorted, and will B<NOT> include the C<.> and C<..> entries.
532 536
533The callback a single argument which is either C<undef> or an array-ref 537The callback is passed a single argument which is either C<undef> or an
534with the filenames. 538array-ref with the filenames.
539
540
541=item aio_readdirx $pathname, $flags, $callback->($entries, $flags)
542
543Quite similar to C<aio_readdir>, but the C<$flags> argument allows to tune
544behaviour and output format. In case of an error, C<$entries> will be
545C<undef>.
546
547The flags are a combination of the following constants, ORed together (the
548flags will also be passed to the callback, possibly modified):
549
550=over 4
551
552=item IO::AIO::READDIR_DENTS
553
554When this flag is off, then the callback gets an arrayref with of names
555only (as with C<aio_readdir>), otherwise it gets an arrayref with
556C<[$name, $type, $inode]> arrayrefs, each describing a single directory
557entry in more detail.
558
559C<$name> is the name of the entry.
560
561C<$type> is one of the C<IO::AIO::DT_xxx> constants:
562
563C<IO::AIO::DT_UNKNOWN>, C<IO::AIO::DT_FIFO>, C<IO::AIO::DT_CHR>, C<IO::AIO::DT_DIR>,
564C<IO::AIO::DT_BLK>, C<IO::AIO::DT_REG>, C<IO::AIO::DT_LNK>, C<IO::AIO::DT_SOCK>,
565C<IO::AIO::DT_WHT>.
566
567C<IO::AIO::DT_UNKNOWN> means just that: readdir does not know. If you need to
568know, you have to run stat yourself. Also, for speed reasons, the C<$type>
569scalars are read-only: you can not modify them.
570
571C<$inode> is the inode number (which might not be exact on systems with 64
572bit inode numbers and 32 bit perls). This field has unspecified content on
573systems that do not deliver the inode information.
574
575=item IO::AIO::READDIR_DIRS_FIRST
576
577When this flag is set, then the names will be returned in an order where
578likely directories come first. This is useful when you need to quickly
579find directories, or you want to find all directories while avoiding to
580stat() each entry.
581
582If the system returns type information in readdir, then this is used
583to find directories directly. Otherwise, likely directories are files
584beginning with ".", or otherwise files with no dots, of which files with
585short names are tried first.
586
587=item IO::AIO::READDIR_STAT_ORDER
588
589When this flag is set, then the names will be returned in an order
590suitable for stat()'ing each one. That is, when you plan to stat()
591all files in the given directory, then the returned order will likely
592be fastest.
593
594If both this flag and C<IO::AIO::READDIR_DIRS_FIRST> are specified, then
595the likely dirs come first, resulting in a less optimal stat order.
596
597=item IO::AIO::READDIR_FOUND_UNKNOWN
598
599This flag should not be set when calling C<aio_readdirx>. Instead, it
600is being set by C<aio_readdirx>, when any of the C<$type>'s found were
601C<IO::AIO::DT_UNKNOWN>. The absense of this flag therefore indicates that all
602C<$type>'s are known, which can be used to speed up some algorithms.
603
604=back
535 605
536 606
537=item aio_load $path, $data, $callback->($status) 607=item aio_load $path, $data, $callback->($status)
538 608
539This is a composite request that tries to fully load the given file into 609This is a composite request that tries to fully load the given file into
540memory. Status is the same as with aio_read. 610memory. Status is the same as with aio_read.
541 611
542=cut 612=cut
543 613
544sub aio_load($$;$) { 614sub aio_load($$;$) {
545 aio_block {
546 my ($path, undef, $cb) = @_; 615 my ($path, undef, $cb) = @_;
547 my $data = \$_[1]; 616 my $data = \$_[1];
548 617
549 my $pri = aioreq_pri; 618 my $pri = aioreq_pri;
550 my $grp = aio_group $cb; 619 my $grp = aio_group $cb;
620
621 aioreq_pri $pri;
622 add $grp aio_open $path, O_RDONLY, 0, sub {
623 my $fh = shift
624 or return $grp->result (-1);
551 625
552 aioreq_pri $pri; 626 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), $$data, 0, sub { 627 add $grp aio_read $fh, 0, (-s $fh), $$data, 0, sub {
559 $grp->result ($_[0]); 628 $grp->result ($_[0]);
560 };
561 }; 629 };
562
563 $grp
564 } 630 };
631
632 $grp
565} 633}
566 634
567=item aio_copy $srcpath, $dstpath, $callback->($status) 635=item aio_copy $srcpath, $dstpath, $callback->($status)
568 636
569Try to copy the I<file> (directories not supported as either source or 637Try to copy the I<file> (directories not supported as either source or
570destination) from C<$srcpath> to C<$dstpath> and call the callback with 638destination) from C<$srcpath> to C<$dstpath> and call the callback with
571the C<0> (error) or C<-1> ok. 639the C<0> (error) or C<-1> ok.
572 640
573This is a composite request that it creates the destination file with 641This is a composite request that creates the destination file with
574mode 0200 and copies the contents of the source file into it using 642mode 0200 and copies the contents of the source file into it using
575C<aio_sendfile>, followed by restoring atime, mtime, access mode and 643C<aio_sendfile>, followed by restoring atime, mtime, access mode and
576uid/gid, in that order. 644uid/gid, in that order.
577 645
578If an error occurs, the partial destination file will be unlinked, if 646If an error occurs, the partial destination file will be unlinked, if
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580errors are being ignored. 648errors are being ignored.
581 649
582=cut 650=cut
583 651
584sub aio_copy($$;$) { 652sub aio_copy($$;$) {
585 aio_block {
586 my ($src, $dst, $cb) = @_; 653 my ($src, $dst, $cb) = @_;
587 654
588 my $pri = aioreq_pri; 655 my $pri = aioreq_pri;
589 my $grp = aio_group $cb; 656 my $grp = aio_group $cb;
590 657
591 aioreq_pri $pri; 658 aioreq_pri $pri;
592 add $grp aio_open $src, O_RDONLY, 0, sub { 659 add $grp aio_open $src, O_RDONLY, 0, sub {
593 if (my $src_fh = $_[0]) { 660 if (my $src_fh = $_[0]) {
594 my @stat = stat $src_fh; 661 my @stat = stat $src_fh; # hmm, might bock over nfs?
595 662
596 aioreq_pri $pri; 663 aioreq_pri $pri;
597 add $grp aio_open $dst, O_CREAT | O_WRONLY | O_TRUNC, 0200, sub { 664 add $grp aio_open $dst, O_CREAT | O_WRONLY | O_TRUNC, 0200, sub {
598 if (my $dst_fh = $_[0]) { 665 if (my $dst_fh = $_[0]) {
599 aioreq_pri $pri; 666 aioreq_pri $pri;
600 add $grp aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub { 667 add $grp aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub {
601 if ($_[0] == $stat[7]) { 668 if ($_[0] == $stat[7]) {
602 $grp->result (0); 669 $grp->result (0);
603 close $src_fh; 670 close $src_fh;
604 671
605 # those should not normally block. should. should. 672 my $ch = sub {
606 utime $stat[8], $stat[9], $dst;
607 chmod $stat[2] & 07777, $dst_fh;
608 chown $stat[4], $stat[5], $dst_fh;
609
610 aioreq_pri $pri; 673 aioreq_pri $pri;
674 add $grp aio_chmod $dst_fh, $stat[2] & 07777, sub {
675 aioreq_pri $pri;
676 add $grp aio_chown $dst_fh, $stat[4], $stat[5], sub {
677 aioreq_pri $pri;
611 add $grp aio_close $dst_fh; 678 add $grp aio_close $dst_fh;
612 } else { 679 }
613 $grp->result (-1);
614 close $src_fh;
615 close $dst_fh;
616
617 aioreq $pri; 680 };
618 add $grp aio_unlink $dst;
619 } 681 };
682
683 aioreq_pri $pri;
684 add $grp aio_utime $dst_fh, $stat[8], $stat[9], sub {
685 if ($_[0] < 0 && $! == ENOSYS) {
686 aioreq_pri $pri;
687 add $grp aio_utime $dst, $stat[8], $stat[9], $ch;
688 } else {
689 $ch->();
690 }
691 };
692 } else {
693 $grp->result (-1);
694 close $src_fh;
695 close $dst_fh;
696
697 aioreq $pri;
698 add $grp aio_unlink $dst;
620 }; 699 }
621 } else {
622 $grp->result (-1);
623 } 700 };
701 } else {
702 $grp->result (-1);
624 }, 703 }
625
626 } else {
627 $grp->result (-1);
628 } 704 },
705
706 } else {
707 $grp->result (-1);
629 }; 708 }
630
631 $grp
632 } 709 };
710
711 $grp
633} 712}
634 713
635=item aio_move $srcpath, $dstpath, $callback->($status) 714=item aio_move $srcpath, $dstpath, $callback->($status)
636 715
637Try to move the I<file> (directories not supported as either source or 716Try to move the I<file> (directories not supported as either source or
638destination) from C<$srcpath> to C<$dstpath> and call the callback with 717destination) from C<$srcpath> to C<$dstpath> and call the callback with
639the C<0> (error) or C<-1> ok. 718the C<0> (error) or C<-1> ok.
640 719
641This is a composite request that tries to rename(2) the file first. If 720This 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 721rename fails with C<EXDEV>, it copies the file with C<aio_copy> and, if
643that is successful, unlinking the C<$srcpath>. 722that is successful, unlinks the C<$srcpath>.
644 723
645=cut 724=cut
646 725
647sub aio_move($$;$) { 726sub aio_move($$;$) {
648 aio_block {
649 my ($src, $dst, $cb) = @_; 727 my ($src, $dst, $cb) = @_;
650 728
651 my $pri = aioreq_pri; 729 my $pri = aioreq_pri;
652 my $grp = aio_group $cb; 730 my $grp = aio_group $cb;
653 731
654 aioreq_pri $pri; 732 aioreq_pri $pri;
655 add $grp aio_rename $src, $dst, sub { 733 add $grp aio_rename $src, $dst, sub {
656 if ($_[0] && $! == EXDEV) { 734 if ($_[0] && $! == EXDEV) {
657 aioreq_pri $pri; 735 aioreq_pri $pri;
658 add $grp aio_copy $src, $dst, sub { 736 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]); 737 $grp->result ($_[0]);
738
739 if (!$_[0]) {
740 aioreq_pri $pri;
741 add $grp aio_unlink $src;
742 }
668 } 743 };
744 } else {
745 $grp->result ($_[0]);
669 }; 746 }
670
671 $grp
672 } 747 };
748
749 $grp
673} 750}
674 751
675=item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs) 752=item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs)
676 753
677Scans a directory (similar to C<aio_readdir>) but additionally tries to 754Scans a directory (similar to C<aio_readdir>) but additionally tries to
… …
697 774
698Implementation notes. 775Implementation notes.
699 776
700The C<aio_readdir> cannot be avoided, but C<stat()>'ing every entry can. 777The C<aio_readdir> cannot be avoided, but C<stat()>'ing every entry can.
701 778
779If readdir returns file type information, then this is used directly to
780find directories.
781
702After reading the directory, the modification time, size etc. of the 782Otherwise, after reading the directory, the modification time, size etc.
703directory before and after the readdir is checked, and if they match (and 783of the directory before and after the readdir is checked, and if they
704isn't the current time), the link count will be used to decide how many 784match (and isn't the current time), the link count will be used to decide
705entries are directories (if >= 2). Otherwise, no knowledge of the number 785how many entries are directories (if >= 2). Otherwise, no knowledge of the
706of subdirectories will be assumed. 786number of subdirectories will be assumed.
707 787
708Then entries will be sorted into likely directories (everything without 788Then entries will be sorted into likely directories a non-initial dot
709a non-initial dot currently) and likely non-directories (everything 789currently) and likely non-directories (see C<aio_readdirx>). Then every
710else). Then every entry plus an appended C</.> will be C<stat>'ed, 790entry plus an appended C</.> will be C<stat>'ed, likely directories first,
711likely directories first. If that succeeds, it assumes that the entry 791in order of their inode numbers. If that succeeds, it assumes that the
712is a directory or a symlink to directory (which will be checked 792entry is a directory or a symlink to directory (which will be checked
713seperately). This is often faster than stat'ing the entry itself because 793seperately). This is often faster than stat'ing the entry itself because
714filesystems might detect the type of the entry without reading the inode 794filesystems might detect the type of the entry without reading the inode
715data (e.g. ext2fs filetype feature). 795data (e.g. ext2fs filetype feature), even on systems that cannot return
796the filetype information on readdir.
716 797
717If the known number of directories (link count - 2) has been reached, the 798If the known number of directories (link count - 2) has been reached, the
718rest of the entries is assumed to be non-directories. 799rest of the entries is assumed to be non-directories.
719 800
720This only works with certainty on POSIX (= UNIX) filesystems, which 801This only works with certainty on POSIX (= UNIX) filesystems, which
… …
725directory counting heuristic. 806directory counting heuristic.
726 807
727=cut 808=cut
728 809
729sub aio_scandir($$;$) { 810sub aio_scandir($$;$) {
730 aio_block {
731 my ($path, $maxreq, $cb) = @_; 811 my ($path, $maxreq, $cb) = @_;
732 812
733 my $pri = aioreq_pri; 813 my $pri = aioreq_pri;
734 814
735 my $grp = aio_group $cb; 815 my $grp = aio_group $cb;
736 816
737 $maxreq = 4 if $maxreq <= 0; 817 $maxreq = 4 if $maxreq <= 0;
738 818
739 # stat once 819 # stat once
820 aioreq_pri $pri;
821 add $grp aio_stat $path, sub {
822 return $grp->result () if $_[0];
823 my $now = time;
824 my $hash1 = join ":", (stat _)[0,1,3,7,9];
825
826 # read the directory entries
740 aioreq_pri $pri; 827 aioreq_pri $pri;
741 add $grp aio_stat $path, sub { 828 add $grp aio_readdirx $path, READDIR_DIRS_FIRST, sub {
829 my $entries = shift
742 return $grp->result () if $_[0]; 830 or return $grp->result ();
743 my $now = time;
744 my $hash1 = join ":", (stat _)[0,1,3,7,9];
745 831
746 # read the directory entries 832 # stat the dir another time
747 aioreq_pri $pri; 833 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 { 834 add $grp aio_stat $path, sub {
755 my $hash2 = join ":", (stat _)[0,1,3,7,9]; 835 my $hash2 = join ":", (stat _)[0,1,3,7,9];
756 836
757 my $ndirs; 837 my $ndirs;
758 838
759 # take the slow route if anything looks fishy 839 # take the slow route if anything looks fishy
760 if ($hash1 ne $hash2 or (stat _)[9] == $now) { 840 if ($hash1 ne $hash2 or (stat _)[9] == $now) {
761 $ndirs = -1; 841 $ndirs = -1;
762 } else { 842 } else {
763 # if nlink == 2, we are finished 843 # if nlink == 2, we are finished
764 # on non-posix-fs's, we rely on nlink < 2 844 # for non-posix-fs's, we rely on nlink < 2
765 $ndirs = (stat _)[3] - 2 845 $ndirs = (stat _)[3] - 2
766 or return $grp->result ([], $entries); 846 or return $grp->result ([], $entries);
767 } 847 }
768 848
769 # sort into likely dirs and likely nondirs
770 # dirs == files without ".", short entries first
771 $entries = [map $_->[0],
772 sort { $b->[1] cmp $a->[1] }
773 map [$_, sprintf "%s%04d", (/.\./ ? "1" : "0"), length],
774 @$entries];
775
776 my (@dirs, @nondirs); 849 my (@dirs, @nondirs);
777 850
778 my $statgrp = add $grp aio_group sub { 851 my $statgrp = add $grp aio_group sub {
779 $grp->result (\@dirs, \@nondirs); 852 $grp->result (\@dirs, \@nondirs);
780 }; 853 };
781 854
782 limit $statgrp $maxreq; 855 limit $statgrp $maxreq;
783 feed $statgrp sub { 856 feed $statgrp sub {
784 return unless @$entries; 857 return unless @$entries;
785 my $entry = pop @$entries; 858 my $entry = shift @$entries;
786 859
787 aioreq_pri $pri; 860 aioreq_pri $pri;
788 add $statgrp aio_stat "$path/$entry/.", sub { 861 add $statgrp aio_stat "$path/$entry/.", sub {
789 if ($_[0] < 0) { 862 if ($_[0] < 0) {
790 push @nondirs, $entry; 863 push @nondirs, $entry;
791 } else { 864 } else {
792 # need to check for real directory 865 # need to check for real directory
793 aioreq_pri $pri; 866 aioreq_pri $pri;
794 add $statgrp aio_lstat "$path/$entry", sub { 867 add $statgrp aio_lstat "$path/$entry", sub {
795 if (-d _) { 868 if (-d _) {
796 push @dirs, $entry; 869 push @dirs, $entry;
797 870
798 unless (--$ndirs) { 871 unless (--$ndirs) {
799 push @nondirs, @$entries; 872 push @nondirs, @$entries;
800 feed $statgrp; 873 feed $statgrp;
801 }
802 } else {
803 push @nondirs, $entry;
804 } 874 }
875 } else {
876 push @nondirs, $entry;
805 } 877 }
806 } 878 }
807 }; 879 }
808 }; 880 };
809 }; 881 };
810 }; 882 };
811 }; 883 };
812
813 $grp
814 } 884 };
885
886 $grp
815} 887}
816 888
817=item aio_rmtree $path, $callback->($status) 889=item aio_rmtree $path, $callback->($status)
818 890
819Delete a directory tree starting (and including) C<$path>, return the 891Delete a directory tree starting (and including) C<$path>, return the
… …
823 895
824=cut 896=cut
825 897
826sub aio_rmtree; 898sub aio_rmtree;
827sub aio_rmtree($;$) { 899sub aio_rmtree($;$) {
828 aio_block {
829 my ($path, $cb) = @_; 900 my ($path, $cb) = @_;
830 901
831 my $pri = aioreq_pri; 902 my $pri = aioreq_pri;
832 my $grp = aio_group $cb; 903 my $grp = aio_group $cb;
833 904
834 aioreq_pri $pri; 905 aioreq_pri $pri;
835 add $grp aio_scandir $path, 0, sub { 906 add $grp aio_scandir $path, 0, sub {
836 my ($dirs, $nondirs) = @_; 907 my ($dirs, $nondirs) = @_;
837 908
838 my $dirgrp = aio_group sub { 909 my $dirgrp = aio_group sub {
839 add $grp aio_rmdir $path, sub { 910 add $grp aio_rmdir $path, sub {
840 $grp->result ($_[0]); 911 $grp->result ($_[0]);
841 };
842 }; 912 };
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 }; 913 };
849 914
850 $grp 915 (aioreq_pri $pri), add $dirgrp aio_rmtree "$path/$_" for @$dirs;
916 (aioreq_pri $pri), add $dirgrp aio_unlink "$path/$_" for @$nondirs;
917
918 add $grp $dirgrp;
851 } 919 };
920
921 $grp
852} 922}
853 923
854=item aio_sync $callback->($status) 924=item aio_sync $callback->($status)
855 925
856Asynchronously call sync and call the callback when finished. 926Asynchronously call sync and call the callback when finished.
… …
866callback with the fdatasync result code. 936callback with the fdatasync result code.
867 937
868If this call isn't available because your OS lacks it or it couldn't be 938If 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. 939detected, it will be emulated by calling C<fsync> instead.
870 940
941=item aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status)
942
943Sync the data portion of the file specified by C<$offset> and C<$length>
944to disk (but NOT the metadata), by calling the Linux-specific
945sync_file_range call. If sync_file_range is not available or it returns
946ENOSYS, then fdatasync or fsync is being substituted.
947
948C<$flags> can be a combination of C<IO::AIO::SYNC_FILE_RANGE_WAIT_BEFORE>,
949C<IO::AIO::SYNC_FILE_RANGE_WRITE> and
950C<IO::AIO::SYNC_FILE_RANGE_WAIT_AFTER>: refer to the sync_file_range
951manpage for details.
952
871=item aio_pathsync $path, $callback->($status) 953=item aio_pathsync $path, $callback->($status)
872 954
873This request tries to open, fsync and close the given path. This is a 955This request tries to open, fsync and close the given path. This is a
874composite request intended tosync directories after directory operations 956composite request intended to sync directories after directory operations
875(E.g. rename). This might not work on all operating systems or have any 957(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 958specific effect, but usually it makes sure that directory changes get
877written to disc. It works for anything that can be opened for read-only, 959written to disc. It works for anything that can be opened for read-only,
878not just directories. 960not just directories.
879 961
880Passes C<0> when everything went ok, and C<-1> on error. 962Passes C<0> when everything went ok, and C<-1> on error.
881 963
882=cut 964=cut
883 965
884sub aio_pathsync($;$) { 966sub aio_pathsync($;$) {
885 aio_block {
886 my ($path, $cb) = @_; 967 my ($path, $cb) = @_;
887 968
888 my $pri = aioreq_pri; 969 my $pri = aioreq_pri;
889 my $grp = aio_group $cb; 970 my $grp = aio_group $cb;
890 971
891 aioreq_pri $pri; 972 aioreq_pri $pri;
892 add $grp aio_open $path, O_RDONLY, 0, sub { 973 add $grp aio_open $path, O_RDONLY, 0, sub {
893 my ($fh) = @_; 974 my ($fh) = @_;
894 if ($fh) { 975 if ($fh) {
976 aioreq_pri $pri;
977 add $grp aio_fsync $fh, sub {
978 $grp->result ($_[0]);
979
895 aioreq_pri $pri; 980 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; 981 add $grp aio_close $fh;
901 };
902 } else {
903 $grp->result (-1);
904 } 982 };
983 } else {
984 $grp->result (-1);
905 }; 985 }
906
907 $grp
908 } 986 };
987
988 $grp
909} 989}
910 990
911=item aio_group $callback->(...) 991=item aio_group $callback->(...)
912 992
913This is a very special aio request: Instead of doing something, it is a 993This is a very special aio request: Instead of doing something, it is a
… …
964=item cancel $req 1044=item cancel $req
965 1045
966Cancels the request, if possible. Has the effect of skipping execution 1046Cancels the request, if possible. Has the effect of skipping execution
967when entering the B<execute> state and skipping calling the callback when 1047when entering the B<execute> state and skipping calling the callback when
968entering the the B<result> state, but will leave the request otherwise 1048entering the the B<result> state, but will leave the request otherwise
969untouched. That means that requests that currently execute will not be 1049untouched (with the exception of readdir). That means that requests that
970stopped and resources held by the request will not be freed prematurely. 1050currently execute will not be stopped and resources held by the request
1051will not be freed prematurely.
971 1052
972=item cb $req $callback->(...) 1053=item cb $req $callback->(...)
973 1054
974Replace (or simply set) the callback registered to the request. 1055Replace (or simply set) the callback registered to the request.
975 1056
… …
1026Their lifetime, simplified, looks like this: when they are empty, they 1107Their lifetime, simplified, looks like this: when they are empty, they
1027will finish very quickly. If they contain only requests that are in the 1108will finish very quickly. If they contain only requests that are in the
1028C<done> state, they will also finish. Otherwise they will continue to 1109C<done> state, they will also finish. Otherwise they will continue to
1029exist. 1110exist.
1030 1111
1031That means after creating a group you have some time to add requests. And 1112That 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 1113(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 1114the C<poll_cb>). And in the callbacks of those requests, you can add
1034itself finish. 1115further requests to the group. And only when all those requests have
1116finished will the the group itself finish.
1035 1117
1036=over 4 1118=over 4
1037 1119
1038=item add $grp ... 1120=item add $grp ...
1039 1121
… …
1072=item feed $grp $callback->($grp) 1154=item feed $grp $callback->($grp)
1073 1155
1074Sets a feeder/generator on this group: every group can have an attached 1156Sets a feeder/generator on this group: every group can have an attached
1075generator that generates requests if idle. The idea behind this is that, 1157generator 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, 1158although you could just queue as many requests as you want in a group,
1077this might starve other requests for a potentially long time. For 1159this might starve other requests for a potentially long time. For example,
1078example, C<aio_scandir> might generate hundreds of thousands C<aio_stat> 1160C<aio_scandir> might generate hundreds of thousands C<aio_stat> requests,
1079requests, delaying any later requests for a long time. 1161delaying any later requests for a long time.
1080 1162
1081To avoid this, and allow incremental generation of requests, you can 1163To avoid this, and allow incremental generation of requests, you can
1082instead a group and set a feeder on it that generates those requests. The 1164instead 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>, 1165feed 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 1166below) requests active in the group itself and is expected to queue more
… …
1088not impose any limits). 1170not impose any limits).
1089 1171
1090If the feed does not queue more requests when called, it will be 1172If the feed does not queue more requests when called, it will be
1091automatically removed from the group. 1173automatically removed from the group.
1092 1174
1093If the feed limit is C<0>, it will be set to C<2> automatically. 1175If the feed limit is C<0> when this method is called, it will be set to
1176C<2> automatically.
1094 1177
1095Example: 1178Example:
1096 1179
1097 # stat all files in @files, but only ever use four aio requests concurrently: 1180 # stat all files in @files, but only ever use four aio requests concurrently:
1098 1181
… …
1110Sets the feeder limit for the group: The feeder will be called whenever 1193Sets the feeder limit for the group: The feeder will be called whenever
1111the group contains less than this many requests. 1194the group contains less than this many requests.
1112 1195
1113Setting the limit to C<0> will pause the feeding process. 1196Setting the limit to C<0> will pause the feeding process.
1114 1197
1198The default value for the limit is C<0>, but note that setting a feeder
1199automatically bumps it up to C<2>.
1200
1115=back 1201=back
1116 1202
1117=head2 SUPPORT FUNCTIONS 1203=head2 SUPPORT FUNCTIONS
1118 1204
1119=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION 1205=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION
… …
1121=over 4 1207=over 4
1122 1208
1123=item $fileno = IO::AIO::poll_fileno 1209=item $fileno = IO::AIO::poll_fileno
1124 1210
1125Return the I<request result pipe file descriptor>. This filehandle must be 1211Return the I<request result pipe file descriptor>. This filehandle must be
1126polled for reading by some mechanism outside this module (e.g. Event or 1212polled for reading by some mechanism outside this module (e.g. EV, Glib,
1127select, see below or the SYNOPSIS). If the pipe becomes readable you have 1213select and so on, see below or the SYNOPSIS). If the pipe becomes readable
1128to call C<poll_cb> to check the results. 1214you have to call C<poll_cb> to check the results.
1129 1215
1130See C<poll_cb> for an example. 1216See C<poll_cb> for an example.
1131 1217
1132=item IO::AIO::poll_cb 1218=item IO::AIO::poll_cb
1133 1219
1134Process some outstanding events on the result pipe. You have to call this 1220Process some outstanding events on the result pipe. You have to call this
1135regularly. Returns the number of events processed. Returns immediately 1221regularly. Returns C<0> if all events could be processed, or C<-1> if it
1222returned earlier for whatever reason. Returns immediately when no events
1136when no events are outstanding. The amount of events processed depends on 1223are 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>. 1224C<IO::AIO::max_poll_req> and C<IO::AIO::max_poll_time>.
1138 1225
1139If not all requests were processed for whatever reason, the filehandle 1226If not all requests were processed for whatever reason, the filehandle
1140will still be ready when C<poll_cb> returns. 1227will still be ready when C<poll_cb> returns, so normally you don't have to
1228do anything special to have it called later.
1141 1229
1142Example: Install an Event watcher that automatically calls 1230Example: Install an Event watcher that automatically calls
1143IO::AIO::poll_cb with high priority: 1231IO::AIO::poll_cb with high priority (more examples can be found in the
1232SYNOPSIS section, at the top of this document):
1144 1233
1145 Event->io (fd => IO::AIO::poll_fileno, 1234 Event->io (fd => IO::AIO::poll_fileno,
1146 poll => 'r', async => 1, 1235 poll => 'r', async => 1,
1147 cb => \&IO::AIO::poll_cb); 1236 cb => \&IO::AIO::poll_cb);
1148 1237
… …
1259 1348
1260The default is probably ok in most situations, especially if thread 1349The default is probably ok in most situations, especially if thread
1261creation is fast. If thread creation is very slow on your system you might 1350creation is fast. If thread creation is very slow on your system you might
1262want to use larger values. 1351want to use larger values.
1263 1352
1264=item $oldmaxreqs = IO::AIO::max_outstanding $maxreqs 1353=item IO::AIO::max_outstanding $maxreqs
1265 1354
1266This is a very bad function to use in interactive programs because it 1355This 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 1356blocks, and a bad way to reduce concurrency because it is inexact: Better
1268use an C<aio_group> together with a feed callback. 1357use an C<aio_group> together with a feed callback.
1269 1358
… …
1274 1363
1275The default value is very large, so there is no practical limit on the 1364The default value is very large, so there is no practical limit on the
1276number of outstanding requests. 1365number of outstanding requests.
1277 1366
1278You can still queue as many requests as you want. Therefore, 1367You can still queue as many requests as you want. Therefore,
1279C<max_oustsanding> is mainly useful in simple scripts (with low values) or 1368C<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). 1369as a stop gap to shield against fatal memory overflow (with large values).
1281 1370
1282=back 1371=back
1283 1372
1284=head3 STATISTICAL INFORMATION 1373=head3 STATISTICAL INFORMATION
… …
1354 1443
1355Known bugs will be fixed in the next release. 1444Known bugs will be fixed in the next release.
1356 1445
1357=head1 SEE ALSO 1446=head1 SEE ALSO
1358 1447
1359L<Coro::AIO>. 1448L<AnyEvent::AIO> for easy integration into event loops, L<Coro::AIO> for a
1449more natural syntax.
1360 1450
1361=head1 AUTHOR 1451=head1 AUTHOR
1362 1452
1363 Marc Lehmann <schmorp@schmorp.de> 1453 Marc Lehmann <schmorp@schmorp.de>
1364 http://home.schmorp.de/ 1454 http://home.schmorp.de/

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