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Revision 1.116 by root, Wed Oct 3 21:27:51 2007 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, 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 $aio_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);
… …
50 \&IO::AIO::poll_cb); 52 \&IO::AIO::poll_cb);
51 53
52=head1 DESCRIPTION 54=head1 DESCRIPTION
53 55
54This module implements asynchronous I/O using whatever means your 56This module implements asynchronous I/O using whatever means your
55operating system supports. 57operating system supports. It is implemented as an interface to C<libeio>
58(L<http://software.schmorp.de/pkg/libeio.html>).
56 59
57Asynchronous means that operations that can normally block your program 60Asynchronous means that operations that can normally block your program
58(e.g. reading from disk) will be done asynchronously: the operation 61(e.g. reading from disk) will be done asynchronously: the operation
59will 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
60is 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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64on 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
65concurrently. 68concurrently.
66 69
67While most of this works on all types of file descriptors (for 70While most of this works on all types of file descriptors (for
68example sockets), using these functions on file descriptors that 71example sockets), using these functions on file descriptors that
69support nonblocking operation (again, sockets, pipes etc.) is very 72support nonblocking operation (again, sockets, pipes etc.) is
70inefficient. 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>
71module): IO::AIO will naturally fit into such an event loop itself. 74module): IO::AIO will naturally fit into such an event loop itself.
72 75
73In this version, a number of threads are started that execute your 76In this version, a number of threads are started that execute your
74requests and signal their completion. You don't need thread support 77requests and signal their completion. You don't need thread support
75in 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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85yourself, 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
86call C<poll_cb> (or other C<aio_> functions) recursively. 89call C<poll_cb> (or other C<aio_> functions) recursively.
87 90
88=head2 EXAMPLE 91=head2 EXAMPLE
89 92
90This is a simple example that uses the Event module and loads 93This is a simple example that uses the EV module and loads
91F</etc/passwd> asynchronously: 94F</etc/passwd> asynchronously:
92 95
93 use Fcntl; 96 use Fcntl;
94 use Event; 97 use EV;
95 use IO::AIO; 98 use IO::AIO;
96 99
97 # register the IO::AIO callback with Event 100 # register the IO::AIO callback with EV
98 Event->io (fd => IO::AIO::poll_fileno, 101 my $aio_w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb;
99 poll => 'r',
100 cb => \&IO::AIO::poll_cb);
101 102
102 # queue the request to open /etc/passwd 103 # queue the request to open /etc/passwd
103 aio_open "/etc/passwd", O_RDONLY, 0, sub { 104 aio_open "/etc/passwd", O_RDONLY, 0, sub {
104 my $fh = shift 105 my $fh = shift
105 or die "error while opening: $!"; 106 or die "error while opening: $!";
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117 118
118 # file contents now in $contents 119 # file contents now in $contents
119 print $contents; 120 print $contents;
120 121
121 # exit event loop and program 122 # exit event loop and program
122 Event::unloop; 123 EV::unloop;
123 }; 124 };
124 }; 125 };
125 126
126 # possibly queue up other requests, or open GUI windows, 127 # possibly queue up other requests, or open GUI windows,
127 # check for sockets etc. etc. 128 # check for sockets etc. etc.
128 129
129 # process events as long as there are some: 130 # process events as long as there are some:
130 Event::loop; 131 EV::loop;
131 132
132=head1 REQUEST ANATOMY AND LIFETIME 133=head1 REQUEST ANATOMY AND LIFETIME
133 134
134Every 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
135directly visible to Perl. 136directly visible to Perl.
… …
183 184
184=cut 185=cut
185 186
186package IO::AIO; 187package IO::AIO;
187 188
189use Carp ();
190
188no warnings; 191no warnings;
189use strict 'vars'; 192use strict 'vars';
190 193
191use base 'Exporter'; 194use base 'Exporter';
192 195
193BEGIN { 196BEGIN {
194 our $VERSION = '2.5'; 197 our $VERSION = '3.23';
195 198
196 our @AIO_REQ = qw(aio_sendfile aio_read aio_write aio_open aio_close aio_stat 199 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 200 aio_stat aio_lstat aio_unlink aio_rmdir aio_readdir aio_readdirx
198 aio_readlink aio_fsync aio_fdatasync aio_readahead aio_rename aio_link 201 aio_scandir aio_symlink aio_readlink aio_sync aio_fsync
202 aio_fdatasync aio_sync_file_range aio_pathsync aio_readahead
203 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 204 aio_nop aio_mknod aio_load aio_rmtree aio_mkdir aio_chown
200 aio_chown aio_chmod aio_utime aio_truncate); 205 aio_chmod aio_utime aio_truncate);
206
201 our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice aio_block)); 207 our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice));
202 our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush 208 our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush
203 min_parallel max_parallel max_idle 209 min_parallel max_parallel max_idle
204 nreqs nready npending nthreads 210 nreqs nready npending nthreads
205 max_poll_time max_poll_reqs); 211 max_poll_time max_poll_reqs);
212
213 push @AIO_REQ, qw(aio_busy); # not exported
206 214
207 @IO::AIO::GRP::ISA = 'IO::AIO::REQ'; 215 @IO::AIO::GRP::ISA = 'IO::AIO::REQ';
208 216
209 require XSLoader; 217 require XSLoader;
210 XSLoader::load ("IO::AIO", $VERSION); 218 XSLoader::load ("IO::AIO", $VERSION);
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217All the C<aio_*> calls are more or less thin wrappers around the syscall 225All the C<aio_*> calls are more or less thin wrappers around the syscall
218with the same name (sans C<aio_>). The arguments are similar or identical, 226with the same name (sans C<aio_>). The arguments are similar or identical,
219and they all accept an additional (and optional) C<$callback> argument 227and they all accept an additional (and optional) C<$callback> argument
220which 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
221the 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
222perl, which usually delivers "false") as it's sole argument when the given 230perl, which usually delivers "false") as its sole argument after the given
223syscall has been executed asynchronously. 231syscall has been executed asynchronously.
224 232
225All functions expecting a filehandle keep a copy of the filehandle 233All functions expecting a filehandle keep a copy of the filehandle
226internally until the request has finished. 234internally until the request has finished.
227 235
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241your 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
242environment, d) use Glib::filename_from_unicode on unicode filenames or e) 250environment, d) use Glib::filename_from_unicode on unicode filenames or e)
243use something else to ensure your scalar has the correct contents. 251use something else to ensure your scalar has the correct contents.
244 252
245This 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
246handles correctly wether it is set or not. 254handles correctly whether it is set or not.
247 255
248=over 4 256=over 4
249 257
250=item $prev_pri = aioreq_pri [$pri] 258=item $prev_pri = aioreq_pri [$pri]
251 259
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313=item aio_close $fh, $callback->($status) 321=item aio_close $fh, $callback->($status)
314 322
315Asynchronously close a file and call the callback with the result 323Asynchronously close a file and call the callback with the result
316code. 324code.
317 325
318Unlike the other functions operating on files, this function uses the 326Unfortunately, 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 327closing 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.
326 328
327Having said that, aio_close tries to clean up the filehandle as much as 329Therefore, C<aio_close> will not close the filehandle - instead it will
328possible before handing it to an io thread, and generally does work. 330use dup2 to overwrite the file descriptor with the write-end of a pipe
331(the pipe fd will be created on demand and will be cached).
329 332
333Or in other words: the file descriptor will be closed, but it will not be
334free for reuse until the perl filehandle is closed.
335
336=cut
330 337
331=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval) 338=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
332 339
333=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval) 340=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
334 341
335Reads 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<$fh> and
336into the scalar given by C<$data> and offset C<$dataoffset> and calls the 343C<$offset> into the scalar given by C<$data> and offset C<$dataoffset>
337callback 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
338like the syscall). 345error, just like the syscall).
346
347C<aio_read> will, like C<sysread>, shrink or grow the C<$data> scalar to
348offset plus the actual number of bytes read.
339 349
340If C<$offset> is undefined, then the current file descriptor offset will 350If C<$offset> is undefined, then the current file descriptor offset will
341be used (and updated), otherwise the file descriptor offset will not be 351be used (and updated), otherwise the file descriptor offset will not be
342changed by these calls. 352changed by these calls.
343 353
344If C<$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<$data>.
345 356
346If C<$dataoffset> is less than zero, it will be counted from the end of 357If C<$dataoffset> is less than zero, it will be counted from the end of
347C<$data>. 358C<$data>.
348 359
349The C<$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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521 532
522Unlike 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
523directory (i.e. opendir + readdir + closedir). The entries will not be 534directory (i.e. opendir + readdir + closedir). The entries will not be
524sorted, and will B<NOT> include the C<.> and C<..> entries. 535sorted, and will B<NOT> include the C<.> and C<..> entries.
525 536
526The 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
527with 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
528 605
529 606
530=item aio_load $path, $data, $callback->($status) 607=item aio_load $path, $data, $callback->($status)
531 608
532This 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
533memory. Status is the same as with aio_read. 610memory. Status is the same as with aio_read.
534 611
535=cut 612=cut
536 613
537sub aio_load($$;$) { 614sub aio_load($$;$) {
538 aio_block {
539 my ($path, undef, $cb) = @_; 615 my ($path, undef, $cb) = @_;
540 my $data = \$_[1]; 616 my $data = \$_[1];
541 617
542 my $pri = aioreq_pri; 618 my $pri = aioreq_pri;
543 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);
544 625
545 aioreq_pri $pri; 626 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), $$data, 0, sub { 627 add $grp aio_read $fh, 0, (-s $fh), $$data, 0, sub {
552 $grp->result ($_[0]); 628 $grp->result ($_[0]);
553 };
554 }; 629 };
555
556 $grp
557 } 630 };
631
632 $grp
558} 633}
559 634
560=item aio_copy $srcpath, $dstpath, $callback->($status) 635=item aio_copy $srcpath, $dstpath, $callback->($status)
561 636
562Try 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
563destination) from C<$srcpath> to C<$dstpath> and call the callback with 638destination) from C<$srcpath> to C<$dstpath> and call the callback with
564the C<0> (error) or C<-1> ok. 639the C<0> (error) or C<-1> ok.
565 640
566This is a composite request that it creates the destination file with 641This is a composite request that creates the destination file with
567mode 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
568C<aio_sendfile>, followed by restoring atime, mtime, access mode and 643C<aio_sendfile>, followed by restoring atime, mtime, access mode and
569uid/gid, in that order. 644uid/gid, in that order.
570 645
571If an error occurs, the partial destination file will be unlinked, if 646If an error occurs, the partial destination file will be unlinked, if
… …
573errors are being ignored. 648errors are being ignored.
574 649
575=cut 650=cut
576 651
577sub aio_copy($$;$) { 652sub aio_copy($$;$) {
578 aio_block {
579 my ($src, $dst, $cb) = @_; 653 my ($src, $dst, $cb) = @_;
580 654
581 my $pri = aioreq_pri; 655 my $pri = aioreq_pri;
582 my $grp = aio_group $cb; 656 my $grp = aio_group $cb;
583 657
584 aioreq_pri $pri; 658 aioreq_pri $pri;
585 add $grp aio_open $src, O_RDONLY, 0, sub { 659 add $grp aio_open $src, O_RDONLY, 0, sub {
586 if (my $src_fh = $_[0]) { 660 if (my $src_fh = $_[0]) {
587 my @stat = stat $src_fh; 661 my @stat = stat $src_fh; # hmm, might bock over nfs?
588 662
589 aioreq_pri $pri; 663 aioreq_pri $pri;
590 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 {
591 if (my $dst_fh = $_[0]) { 665 if (my $dst_fh = $_[0]) {
592 aioreq_pri $pri; 666 aioreq_pri $pri;
593 add $grp aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub { 667 add $grp aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub {
594 if ($_[0] == $stat[7]) { 668 if ($_[0] == $stat[7]) {
595 $grp->result (0); 669 $grp->result (0);
596 close $src_fh; 670 close $src_fh;
597 671
598 # those should not normally block. should. should.
599 utime $stat[8], $stat[9], $dst;
600 chmod $stat[2] & 07777, $dst_fh;
601 chown $stat[4], $stat[5], $dst_fh;
602 close $dst_fh;
603 } else { 672 my $ch = sub {
604 $grp->result (-1);
605 close $src_fh;
606 close $dst_fh;
607
608 aioreq $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;
609 add $grp aio_unlink $dst; 678 add $grp aio_close $dst_fh;
679 }
680 };
610 } 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;
611 }; 699 }
612 } else {
613 $grp->result (-1);
614 } 700 };
701 } else {
702 $grp->result (-1);
615 }, 703 }
616
617 } else {
618 $grp->result (-1);
619 } 704 },
705
706 } else {
707 $grp->result (-1);
620 }; 708 }
621
622 $grp
623 } 709 };
710
711 $grp
624} 712}
625 713
626=item aio_move $srcpath, $dstpath, $callback->($status) 714=item aio_move $srcpath, $dstpath, $callback->($status)
627 715
628Try 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
629destination) from C<$srcpath> to C<$dstpath> and call the callback with 717destination) from C<$srcpath> to C<$dstpath> and call the callback with
630the C<0> (error) or C<-1> ok. 718the C<0> (error) or C<-1> ok.
631 719
632This 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
633rename 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
634that is successful, unlinking the C<$srcpath>. 722that is successful, unlinks the C<$srcpath>.
635 723
636=cut 724=cut
637 725
638sub aio_move($$;$) { 726sub aio_move($$;$) {
639 aio_block {
640 my ($src, $dst, $cb) = @_; 727 my ($src, $dst, $cb) = @_;
641 728
642 my $pri = aioreq_pri; 729 my $pri = aioreq_pri;
643 my $grp = aio_group $cb; 730 my $grp = aio_group $cb;
644 731
645 aioreq_pri $pri; 732 aioreq_pri $pri;
646 add $grp aio_rename $src, $dst, sub { 733 add $grp aio_rename $src, $dst, sub {
647 if ($_[0] && $! == EXDEV) { 734 if ($_[0] && $! == EXDEV) {
648 aioreq_pri $pri; 735 aioreq_pri $pri;
649 add $grp aio_copy $src, $dst, sub { 736 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]); 737 $grp->result ($_[0]);
738
739 if (!$_[0]) {
740 aioreq_pri $pri;
741 add $grp aio_unlink $src;
742 }
659 } 743 };
744 } else {
745 $grp->result ($_[0]);
660 }; 746 }
661
662 $grp
663 } 747 };
748
749 $grp
664} 750}
665 751
666=item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs) 752=item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs)
667 753
668Scans a directory (similar to C<aio_readdir>) but additionally tries to 754Scans a directory (similar to C<aio_readdir>) but additionally tries to
… …
688 774
689Implementation notes. 775Implementation notes.
690 776
691The 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.
692 778
779If readdir returns file type information, then this is used directly to
780find directories.
781
693After reading the directory, the modification time, size etc. of the 782Otherwise, after reading the directory, the modification time, size etc.
694directory 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
695isn'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
696entries are directories (if >= 2). Otherwise, no knowledge of the number 785how many entries are directories (if >= 2). Otherwise, no knowledge of the
697of subdirectories will be assumed. 786number of subdirectories will be assumed.
698 787
699Then entries will be sorted into likely directories (everything without 788Then entries will be sorted into likely directories a non-initial dot
700a non-initial dot currently) and likely non-directories (everything 789currently) and likely non-directories (see C<aio_readdirx>). Then every
701else). 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,
702likely directories first. If that succeeds, it assumes that the entry 791in order of their inode numbers. If that succeeds, it assumes that the
703is a directory or a symlink to directory (which will be checked 792entry is a directory or a symlink to directory (which will be checked
704seperately). This is often faster than stat'ing the entry itself because 793seperately). This is often faster than stat'ing the entry itself because
705filesystems might detect the type of the entry without reading the inode 794filesystems might detect the type of the entry without reading the inode
706data (e.g. ext2fs filetype feature). 795data (e.g. ext2fs filetype feature), even on systems that cannot return
796the filetype information on readdir.
707 797
708If 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
709rest of the entries is assumed to be non-directories. 799rest of the entries is assumed to be non-directories.
710 800
711This only works with certainty on POSIX (= UNIX) filesystems, which 801This only works with certainty on POSIX (= UNIX) filesystems, which
… …
716directory counting heuristic. 806directory counting heuristic.
717 807
718=cut 808=cut
719 809
720sub aio_scandir($$;$) { 810sub aio_scandir($$;$) {
721 aio_block {
722 my ($path, $maxreq, $cb) = @_; 811 my ($path, $maxreq, $cb) = @_;
723 812
724 my $pri = aioreq_pri; 813 my $pri = aioreq_pri;
725 814
726 my $grp = aio_group $cb; 815 my $grp = aio_group $cb;
727 816
728 $maxreq = 4 if $maxreq <= 0; 817 $maxreq = 4 if $maxreq <= 0;
729 818
730 # 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
731 aioreq_pri $pri; 827 aioreq_pri $pri;
732 add $grp aio_stat $path, sub { 828 add $grp aio_readdirx $path, READDIR_DIRS_FIRST, sub {
829 my $entries = shift
733 return $grp->result () if $_[0]; 830 or return $grp->result ();
734 my $now = time;
735 my $hash1 = join ":", (stat _)[0,1,3,7,9];
736 831
737 # read the directory entries 832 # stat the dir another time
738 aioreq_pri $pri; 833 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 { 834 add $grp aio_stat $path, sub {
746 my $hash2 = join ":", (stat _)[0,1,3,7,9]; 835 my $hash2 = join ":", (stat _)[0,1,3,7,9];
747 836
748 my $ndirs; 837 my $ndirs;
749 838
750 # take the slow route if anything looks fishy 839 # take the slow route if anything looks fishy
751 if ($hash1 ne $hash2 or (stat _)[9] == $now) { 840 if ($hash1 ne $hash2 or (stat _)[9] == $now) {
752 $ndirs = -1; 841 $ndirs = -1;
753 } else { 842 } else {
754 # if nlink == 2, we are finished 843 # if nlink == 2, we are finished
755 # on non-posix-fs's, we rely on nlink < 2 844 # for non-posix-fs's, we rely on nlink < 2
756 $ndirs = (stat _)[3] - 2 845 $ndirs = (stat _)[3] - 2
757 or return $grp->result ([], $entries); 846 or return $grp->result ([], $entries);
758 } 847 }
759 848
760 # sort into likely dirs and likely nondirs
761 # dirs == files without ".", short entries first
762 $entries = [map $_->[0],
763 sort { $b->[1] cmp $a->[1] }
764 map [$_, sprintf "%s%04d", (/.\./ ? "1" : "0"), length],
765 @$entries];
766
767 my (@dirs, @nondirs); 849 my (@dirs, @nondirs);
768 850
769 my $statgrp = add $grp aio_group sub { 851 my $statgrp = add $grp aio_group sub {
770 $grp->result (\@dirs, \@nondirs); 852 $grp->result (\@dirs, \@nondirs);
771 }; 853 };
772 854
773 limit $statgrp $maxreq; 855 limit $statgrp $maxreq;
774 feed $statgrp sub { 856 feed $statgrp sub {
775 return unless @$entries; 857 return unless @$entries;
776 my $entry = pop @$entries; 858 my $entry = shift @$entries;
777 859
778 aioreq_pri $pri; 860 aioreq_pri $pri;
779 add $statgrp aio_stat "$path/$entry/.", sub { 861 add $statgrp aio_stat "$path/$entry/.", sub {
780 if ($_[0] < 0) { 862 if ($_[0] < 0) {
781 push @nondirs, $entry; 863 push @nondirs, $entry;
782 } else { 864 } else {
783 # need to check for real directory 865 # need to check for real directory
784 aioreq_pri $pri; 866 aioreq_pri $pri;
785 add $statgrp aio_lstat "$path/$entry", sub { 867 add $statgrp aio_lstat "$path/$entry", sub {
786 if (-d _) { 868 if (-d _) {
787 push @dirs, $entry; 869 push @dirs, $entry;
788 870
789 unless (--$ndirs) { 871 unless (--$ndirs) {
790 push @nondirs, @$entries; 872 push @nondirs, @$entries;
791 feed $statgrp; 873 feed $statgrp;
792 }
793 } else {
794 push @nondirs, $entry;
795 } 874 }
875 } else {
876 push @nondirs, $entry;
796 } 877 }
797 } 878 }
798 }; 879 }
799 }; 880 };
800 }; 881 };
801 }; 882 };
802 }; 883 };
803
804 $grp
805 } 884 };
885
886 $grp
806} 887}
807 888
808=item aio_rmtree $path, $callback->($status) 889=item aio_rmtree $path, $callback->($status)
809 890
810Delete a directory tree starting (and including) C<$path>, return the 891Delete a directory tree starting (and including) C<$path>, return the
… …
814 895
815=cut 896=cut
816 897
817sub aio_rmtree; 898sub aio_rmtree;
818sub aio_rmtree($;$) { 899sub aio_rmtree($;$) {
819 aio_block {
820 my ($path, $cb) = @_; 900 my ($path, $cb) = @_;
821 901
822 my $pri = aioreq_pri; 902 my $pri = aioreq_pri;
823 my $grp = aio_group $cb; 903 my $grp = aio_group $cb;
824 904
825 aioreq_pri $pri; 905 aioreq_pri $pri;
826 add $grp aio_scandir $path, 0, sub { 906 add $grp aio_scandir $path, 0, sub {
827 my ($dirs, $nondirs) = @_; 907 my ($dirs, $nondirs) = @_;
828 908
829 my $dirgrp = aio_group sub { 909 my $dirgrp = aio_group sub {
830 add $grp aio_rmdir $path, sub { 910 add $grp aio_rmdir $path, sub {
831 $grp->result ($_[0]); 911 $grp->result ($_[0]);
832 };
833 }; 912 };
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 }; 913 };
840 914
841 $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;
842 } 919 };
920
921 $grp
843} 922}
923
924=item aio_sync $callback->($status)
925
926Asynchronously call sync and call the callback when finished.
844 927
845=item aio_fsync $fh, $callback->($status) 928=item aio_fsync $fh, $callback->($status)
846 929
847Asynchronously call fsync on the given filehandle and call the callback 930Asynchronously call fsync on the given filehandle and call the callback
848with the fsync result code. 931with the fsync result code.
… …
852Asynchronously call fdatasync on the given filehandle and call the 935Asynchronously call fdatasync on the given filehandle and call the
853callback with the fdatasync result code. 936callback with the fdatasync result code.
854 937
855If 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
856detected, it will be emulated by calling C<fsync> instead. 939detected, it will be emulated by calling C<fsync> instead.
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
953=item aio_pathsync $path, $callback->($status)
954
955This request tries to open, fsync and close the given path. This is a
956composite request intended to sync directories after directory operations
957(E.g. rename). This might not work on all operating systems or have any
958specific effect, but usually it makes sure that directory changes get
959written to disc. It works for anything that can be opened for read-only,
960not just directories.
961
962Passes C<0> when everything went ok, and C<-1> on error.
963
964=cut
965
966sub aio_pathsync($;$) {
967 my ($path, $cb) = @_;
968
969 my $pri = aioreq_pri;
970 my $grp = aio_group $cb;
971
972 aioreq_pri $pri;
973 add $grp aio_open $path, O_RDONLY, 0, sub {
974 my ($fh) = @_;
975 if ($fh) {
976 aioreq_pri $pri;
977 add $grp aio_fsync $fh, sub {
978 $grp->result ($_[0]);
979
980 aioreq_pri $pri;
981 add $grp aio_close $fh;
982 };
983 } else {
984 $grp->result (-1);
985 }
986 };
987
988 $grp
989}
857 990
858=item aio_group $callback->(...) 991=item aio_group $callback->(...)
859 992
860This 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
861container for other aio requests, which is useful if you want to bundle 994container for other aio requests, which is useful if you want to bundle
… …
911=item cancel $req 1044=item cancel $req
912 1045
913Cancels the request, if possible. Has the effect of skipping execution 1046Cancels the request, if possible. Has the effect of skipping execution
914when entering the B<execute> state and skipping calling the callback when 1047when entering the B<execute> state and skipping calling the callback when
915entering the the B<result> state, but will leave the request otherwise 1048entering the the B<result> state, but will leave the request otherwise
916untouched. That means that requests that currently execute will not be 1049untouched (with the exception of readdir). That means that requests that
917stopped 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.
918 1052
919=item cb $req $callback->(...) 1053=item cb $req $callback->(...)
920 1054
921Replace (or simply set) the callback registered to the request. 1055Replace (or simply set) the callback registered to the request.
922 1056
… …
973Their lifetime, simplified, looks like this: when they are empty, they 1107Their lifetime, simplified, looks like this: when they are empty, they
974will 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
975C<done> state, they will also finish. Otherwise they will continue to 1109C<done> state, they will also finish. Otherwise they will continue to
976exist. 1110exist.
977 1111
978That 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
979in 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
980group. 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
981itself finish. 1115further requests to the group. And only when all those requests have
1116finished will the the group itself finish.
982 1117
983=over 4 1118=over 4
984 1119
985=item add $grp ... 1120=item add $grp ...
986 1121
… …
998itself. Useful when you queued a lot of events but got a result early. 1133itself. Useful when you queued a lot of events but got a result early.
999 1134
1000=item $grp->result (...) 1135=item $grp->result (...)
1001 1136
1002Set the result value(s) that will be passed to the group callback when all 1137Set 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 1138subrequests have finished and set the groups errno to the current value
1004of errno (just like calling C<errno> without an error number). By default, 1139of errno (just like calling C<errno> without an error number). By default,
1005no argument will be passed and errno is zero. 1140no argument will be passed and errno is zero.
1006 1141
1007=item $grp->errno ([$errno]) 1142=item $grp->errno ([$errno])
1008 1143
… …
1019=item feed $grp $callback->($grp) 1154=item feed $grp $callback->($grp)
1020 1155
1021Sets 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
1022generator that generates requests if idle. The idea behind this is that, 1157generator 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, 1158although you could just queue as many requests as you want in a group,
1024this might starve other requests for a potentially long time. For 1159this might starve other requests for a potentially long time. For example,
1025example, C<aio_scandir> might generate hundreds of thousands C<aio_stat> 1160C<aio_scandir> might generate hundreds of thousands C<aio_stat> requests,
1026requests, delaying any later requests for a long time. 1161delaying any later requests for a long time.
1027 1162
1028To avoid this, and allow incremental generation of requests, you can 1163To avoid this, and allow incremental generation of requests, you can
1029instead 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
1030feed 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>,
1031below) 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
… …
1035not impose any limits). 1170not impose any limits).
1036 1171
1037If 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
1038automatically removed from the group. 1173automatically removed from the group.
1039 1174
1040If 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.
1041 1177
1042Example: 1178Example:
1043 1179
1044 # 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:
1045 1181
… …
1057Sets 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
1058the group contains less than this many requests. 1194the group contains less than this many requests.
1059 1195
1060Setting the limit to C<0> will pause the feeding process. 1196Setting the limit to C<0> will pause the feeding process.
1061 1197
1198The default value for the limit is C<0>, but note that setting a feeder
1199automatically bumps it up to C<2>.
1200
1062=back 1201=back
1063 1202
1064=head2 SUPPORT FUNCTIONS 1203=head2 SUPPORT FUNCTIONS
1065 1204
1066=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION 1205=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION
… …
1068=over 4 1207=over 4
1069 1208
1070=item $fileno = IO::AIO::poll_fileno 1209=item $fileno = IO::AIO::poll_fileno
1071 1210
1072Return the I<request result pipe file descriptor>. This filehandle must be 1211Return the I<request result pipe file descriptor>. This filehandle must be
1073polled 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,
1074select, 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
1075to call C<poll_cb> to check the results. 1214you have to call C<poll_cb> to check the results.
1076 1215
1077See C<poll_cb> for an example. 1216See C<poll_cb> for an example.
1078 1217
1079=item IO::AIO::poll_cb 1218=item IO::AIO::poll_cb
1080 1219
1081Process 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
1082regularly. 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
1083when no events are outstanding. The amount of events processed depends on 1223are 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>. 1224C<IO::AIO::max_poll_req> and C<IO::AIO::max_poll_time>.
1085 1225
1086If not all requests were processed for whatever reason, the filehandle 1226If not all requests were processed for whatever reason, the filehandle
1087will 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.
1088 1229
1089Example: Install an Event watcher that automatically calls 1230Example: Install an Event watcher that automatically calls
1090IO::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):
1091 1233
1092 Event->io (fd => IO::AIO::poll_fileno, 1234 Event->io (fd => IO::AIO::poll_fileno,
1093 poll => 'r', async => 1, 1235 poll => 'r', async => 1,
1094 cb => \&IO::AIO::poll_cb); 1236 cb => \&IO::AIO::poll_cb);
1095 1237
… …
1206 1348
1207The default is probably ok in most situations, especially if thread 1349The default is probably ok in most situations, especially if thread
1208creation 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
1209want to use larger values. 1351want to use larger values.
1210 1352
1211=item $oldmaxreqs = IO::AIO::max_outstanding $maxreqs 1353=item IO::AIO::max_outstanding $maxreqs
1212 1354
1213This 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
1214blocks, 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
1215use an C<aio_group> together with a feed callback. 1357use an C<aio_group> together with a feed callback.
1216 1358
… …
1221 1363
1222The 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
1223number of outstanding requests. 1365number of outstanding requests.
1224 1366
1225You can still queue as many requests as you want. Therefore, 1367You can still queue as many requests as you want. Therefore,
1226C<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
1227as 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).
1228 1370
1229=back 1371=back
1230 1372
1231=head3 STATISTICAL INFORMATION 1373=head3 STATISTICAL INFORMATION
… …
1301 1443
1302Known bugs will be fixed in the next release. 1444Known bugs will be fixed in the next release.
1303 1445
1304=head1 SEE ALSO 1446=head1 SEE ALSO
1305 1447
1306L<Coro::AIO>. 1448L<AnyEvent::AIO> for easy integration into event loops, L<Coro::AIO> for a
1449more natural syntax.
1307 1450
1308=head1 AUTHOR 1451=head1 AUTHOR
1309 1452
1310 Marc Lehmann <schmorp@schmorp.de> 1453 Marc Lehmann <schmorp@schmorp.de>
1311 http://home.schmorp.de/ 1454 http://home.schmorp.de/

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