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Revision 1.111 by root, Mon Aug 13 12:08:13 2007 UTC vs.
Revision 1.156 by root, Tue Jun 16 23:41:59 2009 UTC

… …
26 $req->cancel; # cancel request if still in queue 26 $req->cancel; # cancel request if still in queue
27 27
28 my $grp = aio_group sub { print "all stats done\n" }; 28 my $grp = aio_group sub { print "all stats done\n" };
29 add $grp aio_stat "..." for ...; 29 add $grp aio_stat "..." for ...;
30 30
31 # AnyEvent integration (EV, Event, Glib, Tk, POE, urxvt, pureperl...)
32 use AnyEvent::AIO;
33
31 # AnyEvent integration 34 # EV integration
32 open my $fh, "<&=" . IO::AIO::poll_fileno or die "$!"; 35 my $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.
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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 = '2.4'; 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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311 319
312 320
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. I<WARNING:> although accepted, you should not pass in a perl 324code.
317filehandle here, as perl will likely close the file descriptor another
318time when the filehandle is destroyed. Normally, you can safely call perls
319C<close> or just let filehandles go out of scope.
320 325
321This is supposed to be a bug in the API, so that might change. It's 326Unfortunately, you can't do this to perl. Perl I<insists> very strongly on
322therefore best to avoid this function. 327closing the file descriptor associated with the filehandle itself.
323 328
329Therefore, C<aio_close> will not close the filehandle - instead it will
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).
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
324 337
325=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval) 338=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
326 339
327=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval) 340=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
328 341
329Reads 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<$fh> and
330into the scalar given by C<$data> and offset C<$dataoffset> and calls the 343C<$offset> into the scalar given by C<$data> and offset C<$dataoffset>
331callback 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
332like the syscall). 345error, just like the syscall).
333 346
347C<aio_read> will, like C<sysread>, shrink or grow the C<$data> scalar to
348offset plus the actual number of bytes read.
349
334If C<$offset> is undefined, then the current file offset will be used (and 350If C<$offset> is undefined, then the current file descriptor offset will
335updated), otherwise the file offset will not be changed by these calls. 351be used (and updated), otherwise the file descriptor offset will not be
352changed by these calls.
336 353
337If C<$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<$data>.
338 356
339If C<$dataoffset> is less than zero, it will be counted from the end of 357If C<$dataoffset> is less than zero, it will be counted from the end of
340C<$data>. 358C<$data>.
341 359
342The C<$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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514 532
515Unlike 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
516directory (i.e. opendir + readdir + closedir). The entries will not be 534directory (i.e. opendir + readdir + closedir). The entries will not be
517sorted, and will B<NOT> include the C<.> and C<..> entries. 535sorted, and will B<NOT> include the C<.> and C<..> entries.
518 536
519The 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
520with 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
521 605
522 606
523=item aio_load $path, $data, $callback->($status) 607=item aio_load $path, $data, $callback->($status)
524 608
525This 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
526memory. Status is the same as with aio_read. 610memory. Status is the same as with aio_read.
527 611
528=cut 612=cut
529 613
530sub aio_load($$;$) { 614sub aio_load($$;$) {
531 aio_block {
532 my ($path, undef, $cb) = @_; 615 my ($path, undef, $cb) = @_;
533 my $data = \$_[1]; 616 my $data = \$_[1];
534 617
535 my $pri = aioreq_pri; 618 my $pri = aioreq_pri;
536 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);
537 625
538 aioreq_pri $pri; 626 aioreq_pri $pri;
539 add $grp aio_open $path, O_RDONLY, 0, sub {
540 my $fh = shift
541 or return $grp->result (-1);
542
543 aioreq_pri $pri;
544 add $grp aio_read $fh, 0, (-s $fh), $$data, 0, sub { 627 add $grp aio_read $fh, 0, (-s $fh), $$data, 0, sub {
545 $grp->result ($_[0]); 628 $grp->result ($_[0]);
546 };
547 }; 629 };
548
549 $grp
550 } 630 };
631
632 $grp
551} 633}
552 634
553=item aio_copy $srcpath, $dstpath, $callback->($status) 635=item aio_copy $srcpath, $dstpath, $callback->($status)
554 636
555Try 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
556destination) from C<$srcpath> to C<$dstpath> and call the callback with 638destination) from C<$srcpath> to C<$dstpath> and call the callback with
557the C<0> (error) or C<-1> ok. 639the C<0> (error) or C<-1> ok.
558 640
559This is a composite request that it creates the destination file with 641This is a composite request that creates the destination file with
560mode 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
561C<aio_sendfile>, followed by restoring atime, mtime, access mode and 643C<aio_sendfile>, followed by restoring atime, mtime, access mode and
562uid/gid, in that order. 644uid/gid, in that order.
563 645
564If an error occurs, the partial destination file will be unlinked, if 646If an error occurs, the partial destination file will be unlinked, if
… …
566errors are being ignored. 648errors are being ignored.
567 649
568=cut 650=cut
569 651
570sub aio_copy($$;$) { 652sub aio_copy($$;$) {
571 aio_block {
572 my ($src, $dst, $cb) = @_; 653 my ($src, $dst, $cb) = @_;
573 654
574 my $pri = aioreq_pri; 655 my $pri = aioreq_pri;
575 my $grp = aio_group $cb; 656 my $grp = aio_group $cb;
576 657
577 aioreq_pri $pri; 658 aioreq_pri $pri;
578 add $grp aio_open $src, O_RDONLY, 0, sub { 659 add $grp aio_open $src, O_RDONLY, 0, sub {
579 if (my $src_fh = $_[0]) { 660 if (my $src_fh = $_[0]) {
580 my @stat = stat $src_fh; 661 my @stat = stat $src_fh; # hmm, might bock over nfs?
581 662
582 aioreq_pri $pri; 663 aioreq_pri $pri;
583 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 {
584 if (my $dst_fh = $_[0]) { 665 if (my $dst_fh = $_[0]) {
585 aioreq_pri $pri; 666 aioreq_pri $pri;
586 add $grp aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub { 667 add $grp aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub {
587 if ($_[0] == $stat[7]) { 668 if ($_[0] == $stat[7]) {
588 $grp->result (0); 669 $grp->result (0);
589 close $src_fh; 670 close $src_fh;
590 671
591 # those should not normally block. should. should.
592 utime $stat[8], $stat[9], $dst;
593 chmod $stat[2] & 07777, $dst_fh;
594 chown $stat[4], $stat[5], $dst_fh;
595 close $dst_fh;
596 } else { 672 my $ch = sub {
597 $grp->result (-1);
598 close $src_fh;
599 close $dst_fh;
600
601 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;
602 add $grp aio_unlink $dst; 678 add $grp aio_close $dst_fh;
679 }
680 };
603 } 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;
604 }; 699 }
605 } else {
606 $grp->result (-1);
607 } 700 };
701 } else {
702 $grp->result (-1);
608 }, 703 }
609
610 } else {
611 $grp->result (-1);
612 } 704 },
705
706 } else {
707 $grp->result (-1);
613 }; 708 }
614
615 $grp
616 } 709 };
710
711 $grp
617} 712}
618 713
619=item aio_move $srcpath, $dstpath, $callback->($status) 714=item aio_move $srcpath, $dstpath, $callback->($status)
620 715
621Try 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
622destination) from C<$srcpath> to C<$dstpath> and call the callback with 717destination) from C<$srcpath> to C<$dstpath> and call the callback with
623the C<0> (error) or C<-1> ok. 718the C<0> (error) or C<-1> ok.
624 719
625This 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
626rename 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
627that is successful, unlinking the C<$srcpath>. 722that is successful, unlinks the C<$srcpath>.
628 723
629=cut 724=cut
630 725
631sub aio_move($$;$) { 726sub aio_move($$;$) {
632 aio_block {
633 my ($src, $dst, $cb) = @_; 727 my ($src, $dst, $cb) = @_;
634 728
635 my $pri = aioreq_pri; 729 my $pri = aioreq_pri;
636 my $grp = aio_group $cb; 730 my $grp = aio_group $cb;
637 731
638 aioreq_pri $pri; 732 aioreq_pri $pri;
639 add $grp aio_rename $src, $dst, sub { 733 add $grp aio_rename $src, $dst, sub {
640 if ($_[0] && $! == EXDEV) { 734 if ($_[0] && $! == EXDEV) {
641 aioreq_pri $pri; 735 aioreq_pri $pri;
642 add $grp aio_copy $src, $dst, sub { 736 add $grp aio_copy $src, $dst, sub {
643 $grp->result ($_[0]);
644
645 if (!$_[0]) {
646 aioreq_pri $pri;
647 add $grp aio_unlink $src;
648 }
649 };
650 } else {
651 $grp->result ($_[0]); 737 $grp->result ($_[0]);
738
739 if (!$_[0]) {
740 aioreq_pri $pri;
741 add $grp aio_unlink $src;
742 }
652 } 743 };
744 } else {
745 $grp->result ($_[0]);
653 }; 746 }
654
655 $grp
656 } 747 };
748
749 $grp
657} 750}
658 751
659=item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs) 752=item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs)
660 753
661Scans a directory (similar to C<aio_readdir>) but additionally tries to 754Scans a directory (similar to C<aio_readdir>) but additionally tries to
… …
681 774
682Implementation notes. 775Implementation notes.
683 776
684The 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.
685 778
779If readdir returns file type information, then this is used directly to
780find directories.
781
686After reading the directory, the modification time, size etc. of the 782Otherwise, after reading the directory, the modification time, size etc.
687directory 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
688isn'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
689entries are directories (if >= 2). Otherwise, no knowledge of the number 785how many entries are directories (if >= 2). Otherwise, no knowledge of the
690of subdirectories will be assumed. 786number of subdirectories will be assumed.
691 787
692Then entries will be sorted into likely directories (everything without 788Then entries will be sorted into likely directories a non-initial dot
693a non-initial dot currently) and likely non-directories (everything 789currently) and likely non-directories (see C<aio_readdirx>). Then every
694else). 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,
695likely directories first. If that succeeds, it assumes that the entry 791in order of their inode numbers. If that succeeds, it assumes that the
696is a directory or a symlink to directory (which will be checked 792entry is a directory or a symlink to directory (which will be checked
697seperately). This is often faster than stat'ing the entry itself because 793seperately). This is often faster than stat'ing the entry itself because
698filesystems might detect the type of the entry without reading the inode 794filesystems might detect the type of the entry without reading the inode
699data (e.g. ext2fs filetype feature). 795data (e.g. ext2fs filetype feature), even on systems that cannot return
796the filetype information on readdir.
700 797
701If 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
702rest of the entries is assumed to be non-directories. 799rest of the entries is assumed to be non-directories.
703 800
704This only works with certainty on POSIX (= UNIX) filesystems, which 801This only works with certainty on POSIX (= UNIX) filesystems, which
… …
709directory counting heuristic. 806directory counting heuristic.
710 807
711=cut 808=cut
712 809
713sub aio_scandir($$;$) { 810sub aio_scandir($$;$) {
714 aio_block {
715 my ($path, $maxreq, $cb) = @_; 811 my ($path, $maxreq, $cb) = @_;
716 812
717 my $pri = aioreq_pri; 813 my $pri = aioreq_pri;
718 814
719 my $grp = aio_group $cb; 815 my $grp = aio_group $cb;
720 816
721 $maxreq = 4 if $maxreq <= 0; 817 $maxreq = 4 if $maxreq <= 0;
722 818
723 # 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
724 aioreq_pri $pri; 827 aioreq_pri $pri;
725 add $grp aio_stat $path, sub { 828 add $grp aio_readdirx $path, READDIR_DIRS_FIRST, sub {
829 my $entries = shift
726 return $grp->result () if $_[0]; 830 or return $grp->result ();
727 my $now = time;
728 my $hash1 = join ":", (stat _)[0,1,3,7,9];
729 831
730 # read the directory entries 832 # stat the dir another time
731 aioreq_pri $pri; 833 aioreq_pri $pri;
732 add $grp aio_readdir $path, sub {
733 my $entries = shift
734 or return $grp->result ();
735
736 # stat the dir another time
737 aioreq_pri $pri;
738 add $grp aio_stat $path, sub { 834 add $grp aio_stat $path, sub {
739 my $hash2 = join ":", (stat _)[0,1,3,7,9]; 835 my $hash2 = join ":", (stat _)[0,1,3,7,9];
740 836
741 my $ndirs; 837 my $ndirs;
742 838
743 # take the slow route if anything looks fishy 839 # take the slow route if anything looks fishy
744 if ($hash1 ne $hash2 or (stat _)[9] == $now) { 840 if ($hash1 ne $hash2 or (stat _)[9] == $now) {
745 $ndirs = -1; 841 $ndirs = -1;
746 } else { 842 } else {
747 # if nlink == 2, we are finished 843 # if nlink == 2, we are finished
748 # on non-posix-fs's, we rely on nlink < 2 844 # for non-posix-fs's, we rely on nlink < 2
749 $ndirs = (stat _)[3] - 2 845 $ndirs = (stat _)[3] - 2
750 or return $grp->result ([], $entries); 846 or return $grp->result ([], $entries);
751 } 847 }
752 848
753 # sort into likely dirs and likely nondirs
754 # dirs == files without ".", short entries first
755 $entries = [map $_->[0],
756 sort { $b->[1] cmp $a->[1] }
757 map [$_, sprintf "%s%04d", (/.\./ ? "1" : "0"), length],
758 @$entries];
759
760 my (@dirs, @nondirs); 849 my (@dirs, @nondirs);
761 850
762 my $statgrp = add $grp aio_group sub { 851 my $statgrp = add $grp aio_group sub {
763 $grp->result (\@dirs, \@nondirs); 852 $grp->result (\@dirs, \@nondirs);
764 }; 853 };
765 854
766 limit $statgrp $maxreq; 855 limit $statgrp $maxreq;
767 feed $statgrp sub { 856 feed $statgrp sub {
768 return unless @$entries; 857 return unless @$entries;
769 my $entry = pop @$entries; 858 my $entry = shift @$entries;
770 859
771 aioreq_pri $pri; 860 aioreq_pri $pri;
772 add $statgrp aio_stat "$path/$entry/.", sub { 861 add $statgrp aio_stat "$path/$entry/.", sub {
773 if ($_[0] < 0) { 862 if ($_[0] < 0) {
774 push @nondirs, $entry; 863 push @nondirs, $entry;
775 } else { 864 } else {
776 # need to check for real directory 865 # need to check for real directory
777 aioreq_pri $pri; 866 aioreq_pri $pri;
778 add $statgrp aio_lstat "$path/$entry", sub { 867 add $statgrp aio_lstat "$path/$entry", sub {
779 if (-d _) { 868 if (-d _) {
780 push @dirs, $entry; 869 push @dirs, $entry;
781 870
782 unless (--$ndirs) { 871 unless (--$ndirs) {
783 push @nondirs, @$entries; 872 push @nondirs, @$entries;
784 feed $statgrp; 873 feed $statgrp;
785 }
786 } else {
787 push @nondirs, $entry;
788 } 874 }
875 } else {
876 push @nondirs, $entry;
789 } 877 }
790 } 878 }
791 }; 879 }
792 }; 880 };
793 }; 881 };
794 }; 882 };
795 }; 883 };
796
797 $grp
798 } 884 };
885
886 $grp
799} 887}
800 888
801=item aio_rmtree $path, $callback->($status) 889=item aio_rmtree $path, $callback->($status)
802 890
803Delete a directory tree starting (and including) C<$path>, return the 891Delete a directory tree starting (and including) C<$path>, return the
… …
807 895
808=cut 896=cut
809 897
810sub aio_rmtree; 898sub aio_rmtree;
811sub aio_rmtree($;$) { 899sub aio_rmtree($;$) {
812 aio_block {
813 my ($path, $cb) = @_; 900 my ($path, $cb) = @_;
814 901
815 my $pri = aioreq_pri; 902 my $pri = aioreq_pri;
816 my $grp = aio_group $cb; 903 my $grp = aio_group $cb;
817 904
818 aioreq_pri $pri; 905 aioreq_pri $pri;
819 add $grp aio_scandir $path, 0, sub { 906 add $grp aio_scandir $path, 0, sub {
820 my ($dirs, $nondirs) = @_; 907 my ($dirs, $nondirs) = @_;
821 908
822 my $dirgrp = aio_group sub { 909 my $dirgrp = aio_group sub {
823 add $grp aio_rmdir $path, sub { 910 add $grp aio_rmdir $path, sub {
824 $grp->result ($_[0]); 911 $grp->result ($_[0]);
825 };
826 }; 912 };
827
828 (aioreq_pri $pri), add $dirgrp aio_rmtree "$path/$_" for @$dirs;
829 (aioreq_pri $pri), add $dirgrp aio_unlink "$path/$_" for @$nondirs;
830
831 add $grp $dirgrp;
832 }; 913 };
833 914
834 $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;
835 } 919 };
920
921 $grp
836} 922}
923
924=item aio_sync $callback->($status)
925
926Asynchronously call sync and call the callback when finished.
837 927
838=item aio_fsync $fh, $callback->($status) 928=item aio_fsync $fh, $callback->($status)
839 929
840Asynchronously call fsync on the given filehandle and call the callback 930Asynchronously call fsync on the given filehandle and call the callback
841with the fsync result code. 931with the fsync result code.
… …
845Asynchronously call fdatasync on the given filehandle and call the 935Asynchronously call fdatasync on the given filehandle and call the
846callback with the fdatasync result code. 936callback with the fdatasync result code.
847 937
848If 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
849detected, 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}
850 990
851=item aio_group $callback->(...) 991=item aio_group $callback->(...)
852 992
853This 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
854container 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
… …
904=item cancel $req 1044=item cancel $req
905 1045
906Cancels the request, if possible. Has the effect of skipping execution 1046Cancels the request, if possible. Has the effect of skipping execution
907when entering the B<execute> state and skipping calling the callback when 1047when entering the B<execute> state and skipping calling the callback when
908entering the the B<result> state, but will leave the request otherwise 1048entering the the B<result> state, but will leave the request otherwise
909untouched. That means that requests that currently execute will not be 1049untouched (with the exception of readdir). That means that requests that
910stopped 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.
911 1052
912=item cb $req $callback->(...) 1053=item cb $req $callback->(...)
913 1054
914Replace (or simply set) the callback registered to the request. 1055Replace (or simply set) the callback registered to the request.
915 1056
… …
966Their lifetime, simplified, looks like this: when they are empty, they 1107Their lifetime, simplified, looks like this: when they are empty, they
967will 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
968C<done> state, they will also finish. Otherwise they will continue to 1109C<done> state, they will also finish. Otherwise they will continue to
969exist. 1110exist.
970 1111
971That 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
972in 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
973group. 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
974itself finish. 1115further requests to the group. And only when all those requests have
1116finished will the the group itself finish.
975 1117
976=over 4 1118=over 4
977 1119
978=item add $grp ... 1120=item add $grp ...
979 1121
… …
991itself. 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.
992 1134
993=item $grp->result (...) 1135=item $grp->result (...)
994 1136
995Set 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
996subrequests have finished and set thre groups errno to the current value 1138subrequests have finished and set the groups errno to the current value
997of 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,
998no argument will be passed and errno is zero. 1140no argument will be passed and errno is zero.
999 1141
1000=item $grp->errno ([$errno]) 1142=item $grp->errno ([$errno])
1001 1143
… …
1012=item feed $grp $callback->($grp) 1154=item feed $grp $callback->($grp)
1013 1155
1014Sets 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
1015generator that generates requests if idle. The idea behind this is that, 1157generator that generates requests if idle. The idea behind this is that,
1016although 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,
1017this might starve other requests for a potentially long time. For 1159this might starve other requests for a potentially long time. For example,
1018example, C<aio_scandir> might generate hundreds of thousands C<aio_stat> 1160C<aio_scandir> might generate hundreds of thousands C<aio_stat> requests,
1019requests, delaying any later requests for a long time. 1161delaying any later requests for a long time.
1020 1162
1021To avoid this, and allow incremental generation of requests, you can 1163To avoid this, and allow incremental generation of requests, you can
1022instead 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
1023feed 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>,
1024below) 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
… …
1028not impose any limits). 1170not impose any limits).
1029 1171
1030If 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
1031automatically removed from the group. 1173automatically removed from the group.
1032 1174
1033If 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.
1034 1177
1035Example: 1178Example:
1036 1179
1037 # 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:
1038 1181
… …
1050Sets 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
1051the group contains less than this many requests. 1194the group contains less than this many requests.
1052 1195
1053Setting the limit to C<0> will pause the feeding process. 1196Setting the limit to C<0> will pause the feeding process.
1054 1197
1198The default value for the limit is C<0>, but note that setting a feeder
1199automatically bumps it up to C<2>.
1200
1055=back 1201=back
1056 1202
1057=head2 SUPPORT FUNCTIONS 1203=head2 SUPPORT FUNCTIONS
1058 1204
1059=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION 1205=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION
… …
1061=over 4 1207=over 4
1062 1208
1063=item $fileno = IO::AIO::poll_fileno 1209=item $fileno = IO::AIO::poll_fileno
1064 1210
1065Return the I<request result pipe file descriptor>. This filehandle must be 1211Return the I<request result pipe file descriptor>. This filehandle must be
1066polled 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,
1067select, 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
1068to call C<poll_cb> to check the results. 1214you have to call C<poll_cb> to check the results.
1069 1215
1070See C<poll_cb> for an example. 1216See C<poll_cb> for an example.
1071 1217
1072=item IO::AIO::poll_cb 1218=item IO::AIO::poll_cb
1073 1219
1074Process 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
1075regularly. 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
1076when no events are outstanding. The amount of events processed depends on 1223are outstanding. The amount of events processed depends on the settings of
1077the 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>.
1078 1225
1079If not all requests were processed for whatever reason, the filehandle 1226If not all requests were processed for whatever reason, the filehandle
1080will 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.
1081 1229
1082Example: Install an Event watcher that automatically calls 1230Example: Install an Event watcher that automatically calls
1083IO::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):
1084 1233
1085 Event->io (fd => IO::AIO::poll_fileno, 1234 Event->io (fd => IO::AIO::poll_fileno,
1086 poll => 'r', async => 1, 1235 poll => 'r', async => 1,
1087 cb => \&IO::AIO::poll_cb); 1236 cb => \&IO::AIO::poll_cb);
1088 1237
… …
1199 1348
1200The default is probably ok in most situations, especially if thread 1349The default is probably ok in most situations, especially if thread
1201creation 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
1202want to use larger values. 1351want to use larger values.
1203 1352
1204=item $oldmaxreqs = IO::AIO::max_outstanding $maxreqs 1353=item IO::AIO::max_outstanding $maxreqs
1205 1354
1206This is a very bad function to use in interactive programs because it 1355This is a very bad function to use in interactive programs because it
1207blocks, and a bad way to reduce concurrency because it is inexact: Better 1356blocks, and a bad way to reduce concurrency because it is inexact: Better
1208use an C<aio_group> together with a feed callback. 1357use an C<aio_group> together with a feed callback.
1209 1358
1210Sets the maximum number of outstanding requests to C<$nreqs>. If you 1359Sets the maximum number of outstanding requests to C<$nreqs>. If you
1211to queue up more than this number of requests, the next call to the 1360do queue up more than this number of requests, the next call to the
1212C<poll_cb> (and C<poll_some> and other functions calling C<poll_cb>) 1361C<poll_cb> (and C<poll_some> and other functions calling C<poll_cb>)
1213function will block until the limit is no longer exceeded. 1362function will block until the limit is no longer exceeded.
1214 1363
1215The 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
1216number of outstanding requests. 1365number of outstanding requests.
1217 1366
1218You can still queue as many requests as you want. Therefore, 1367You can still queue as many requests as you want. Therefore,
1219C<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
1220as 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).
1221 1370
1222=back 1371=back
1223 1372
1224=head3 STATISTICAL INFORMATION 1373=head3 STATISTICAL INFORMATION
… …
1246but not yet processed by poll_cb). 1395but not yet processed by poll_cb).
1247 1396
1248=back 1397=back
1249 1398
1250=cut 1399=cut
1251
1252# support function to convert a fd into a perl filehandle
1253sub _fd2fh {
1254 return undef if $_[0] < 0;
1255
1256 # try to generate nice filehandles
1257 my $sym = "IO::AIO::fd#$_[0]";
1258 local *$sym;
1259
1260 open *$sym, "+<&=$_[0]" # usually works under any unix
1261 or open *$sym, "<&=$_[0]" # cygwin needs this
1262 or open *$sym, ">&=$_[0]" # or this
1263 or return undef;
1264
1265 *$sym
1266}
1267 1400
1268min_parallel 8; 1401min_parallel 8;
1269 1402
1270END { flush } 1403END { flush }
1271 1404
… …
1310 1443
1311Known bugs will be fixed in the next release. 1444Known bugs will be fixed in the next release.
1312 1445
1313=head1 SEE ALSO 1446=head1 SEE ALSO
1314 1447
1315L<Coro::AIO>. 1448L<AnyEvent::AIO> for easy integration into event loops, L<Coro::AIO> for a
1449more natural syntax.
1316 1450
1317=head1 AUTHOR 1451=head1 AUTHOR
1318 1452
1319 Marc Lehmann <schmorp@schmorp.de> 1453 Marc Lehmann <schmorp@schmorp.de>
1320 http://home.schmorp.de/ 1454 http://home.schmorp.de/

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