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Revision 1.175 by root, Sun Jan 10 20:37:33 2010 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
34 # EV integration
35 my $w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb;
36
37 # Event integration
38 Event->io (fd => IO::AIO::poll_fileno,
39 poll => 'r',
40 cb => \&IO::AIO::poll_cb);
41
42 # Glib/Gtk2 integration
43 add_watch Glib::IO IO::AIO::poll_fileno,
44 in => sub { IO::AIO::poll_cb; 1 };
45
46 # Tk integration
47 Tk::Event::IO->fileevent (IO::AIO::poll_fileno, "",
48 readable => \&IO::AIO::poll_cb);
49
50 # Danga::Socket integration
51 Danga::Socket->AddOtherFds (IO::AIO::poll_fileno =>
52 \&IO::AIO::poll_cb);
53
54=head1 DESCRIPTION 31=head1 DESCRIPTION
55 32
56This module implements asynchronous I/O using whatever means your 33This module implements asynchronous I/O using whatever means your
57operating system supports. 34operating system supports. It is implemented as an interface to C<libeio>
35(L<http://software.schmorp.de/pkg/libeio.html>).
58 36
59Asynchronous means that operations that can normally block your program 37Asynchronous means that operations that can normally block your program
60(e.g. reading from disk) will be done asynchronously: the operation 38(e.g. reading from disk) will be done asynchronously: the operation
61will still block, but you can do something else in the meantime. This 39will still block, but you can do something else in the meantime. This
62is extremely useful for programs that need to stay interactive even 40is extremely useful for programs that need to stay interactive even
66on a RAID volume or over NFS when you do a number of stat operations 44on a RAID volume or over NFS when you do a number of stat operations
67concurrently. 45concurrently.
68 46
69While most of this works on all types of file descriptors (for 47While most of this works on all types of file descriptors (for
70example sockets), using these functions on file descriptors that 48example sockets), using these functions on file descriptors that
71support nonblocking operation (again, sockets, pipes etc.) is very 49support nonblocking operation (again, sockets, pipes etc.) is
72inefficient. Use an event loop for that (such as the L<Event|Event> 50very inefficient. Use an event loop for that (such as the L<EV>
73module): IO::AIO will naturally fit into such an event loop itself. 51module): IO::AIO will naturally fit into such an event loop itself.
74 52
75In this version, a number of threads are started that execute your 53In this version, a number of threads are started that execute your
76requests and signal their completion. You don't need thread support 54requests and signal their completion. You don't need thread support
77in perl, and the threads created by this module will not be visible 55in perl, and the threads created by this module will not be visible
87yourself, always call C<poll_cb> from within the same thread, or never 65yourself, always call C<poll_cb> from within the same thread, or never
88call C<poll_cb> (or other C<aio_> functions) recursively. 66call C<poll_cb> (or other C<aio_> functions) recursively.
89 67
90=head2 EXAMPLE 68=head2 EXAMPLE
91 69
92This is a simple example that uses the Event module and loads 70This is a simple example that uses the EV module and loads
93F</etc/passwd> asynchronously: 71F</etc/passwd> asynchronously:
94 72
95 use Fcntl; 73 use Fcntl;
96 use Event; 74 use EV;
97 use IO::AIO; 75 use IO::AIO;
98 76
99 # register the IO::AIO callback with Event 77 # register the IO::AIO callback with EV
100 Event->io (fd => IO::AIO::poll_fileno, 78 my $aio_w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb;
101 poll => 'r',
102 cb => \&IO::AIO::poll_cb);
103 79
104 # queue the request to open /etc/passwd 80 # queue the request to open /etc/passwd
105 aio_open "/etc/passwd", O_RDONLY, 0, sub { 81 aio_open "/etc/passwd", O_RDONLY, 0, sub {
106 my $fh = shift 82 my $fh = shift
107 or die "error while opening: $!"; 83 or die "error while opening: $!";
119 95
120 # file contents now in $contents 96 # file contents now in $contents
121 print $contents; 97 print $contents;
122 98
123 # exit event loop and program 99 # exit event loop and program
124 Event::unloop; 100 EV::unloop;
125 }; 101 };
126 }; 102 };
127 103
128 # possibly queue up other requests, or open GUI windows, 104 # possibly queue up other requests, or open GUI windows,
129 # check for sockets etc. etc. 105 # check for sockets etc. etc.
130 106
131 # process events as long as there are some: 107 # process events as long as there are some:
132 Event::loop; 108 EV::loop;
133 109
134=head1 REQUEST ANATOMY AND LIFETIME 110=head1 REQUEST ANATOMY AND LIFETIME
135 111
136Every C<aio_*> function creates a request. which is a C data structure not 112Every C<aio_*> function creates a request. which is a C data structure not
137directly visible to Perl. 113directly visible to Perl.
187 163
188package IO::AIO; 164package IO::AIO;
189 165
190use Carp (); 166use Carp ();
191 167
192no warnings; 168use common::sense;
193use strict 'vars';
194 169
195use base 'Exporter'; 170use base 'Exporter';
196 171
197BEGIN { 172BEGIN {
198 our $VERSION = '3.19'; 173 our $VERSION = '3.5';
199 174
200 our @AIO_REQ = qw(aio_sendfile aio_read aio_write aio_open aio_close 175 our @AIO_REQ = qw(aio_sendfile aio_read aio_write aio_open aio_close
201 aio_stat aio_lstat aio_unlink aio_rmdir aio_readdir aio_readdirx 176 aio_stat aio_lstat aio_unlink aio_rmdir aio_readdir aio_readdirx
202 aio_scandir aio_symlink aio_readlink aio_sync aio_fsync 177 aio_scandir aio_symlink aio_readlink aio_sync aio_fsync
203 aio_fdatasync aio_sync_file_range aio_pathsync aio_readahead 178 aio_fdatasync aio_sync_file_range aio_pathsync aio_readahead
204 aio_rename aio_link aio_move aio_copy aio_group 179 aio_rename aio_link aio_move aio_copy aio_group
205 aio_nop aio_mknod aio_load aio_rmtree aio_mkdir aio_chown 180 aio_nop aio_mknod aio_load aio_rmtree aio_mkdir aio_chown
206 aio_chmod aio_utime aio_truncate); 181 aio_chmod aio_utime aio_truncate
182 aio_msync aio_mtouch aio_statvfs);
207 183
208 our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice)); 184 our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice));
209 our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush 185 our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush
210 min_parallel max_parallel max_idle 186 min_parallel max_parallel max_idle
211 nreqs nready npending nthreads 187 nreqs nready npending nthreads
212 max_poll_time max_poll_reqs); 188 max_poll_time max_poll_reqs
189 sendfile fadvise);
213 190
214 push @AIO_REQ, qw(aio_busy); # not exported 191 push @AIO_REQ, qw(aio_busy); # not exported
215 192
216 @IO::AIO::GRP::ISA = 'IO::AIO::REQ'; 193 @IO::AIO::GRP::ISA = 'IO::AIO::REQ';
217 194
218 require XSLoader; 195 require XSLoader;
219 XSLoader::load ("IO::AIO", $VERSION); 196 XSLoader::load ("IO::AIO", $VERSION);
220} 197}
221 198
222=head1 FUNCTIONS 199=head1 FUNCTIONS
200
201=head2 QUICK OVERVIEW
202
203This section simply lists the prototypes of the most important functions
204for quick reference. See the following sections for function-by-function
205documentation.
206
207 aio_open $pathname, $flags, $mode, $callback->($fh)
208 aio_close $fh, $callback->($status)
209 aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
210 aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
211 aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval)
212 aio_readahead $fh,$offset,$length, $callback->($retval)
213 aio_stat $fh_or_path, $callback->($status)
214 aio_lstat $fh, $callback->($status)
215 aio_statvfs $fh_or_path, $callback->($statvfs)
216 aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
217 aio_chown $fh_or_path, $uid, $gid, $callback->($status)
218 aio_truncate $fh_or_path, $offset, $callback->($status)
219 aio_chmod $fh_or_path, $mode, $callback->($status)
220 aio_unlink $pathname, $callback->($status)
221 aio_mknod $path, $mode, $dev, $callback->($status)
222 aio_link $srcpath, $dstpath, $callback->($status)
223 aio_symlink $srcpath, $dstpath, $callback->($status)
224 aio_readlink $path, $callback->($link)
225 aio_rename $srcpath, $dstpath, $callback->($status)
226 aio_mkdir $pathname, $mode, $callback->($status)
227 aio_rmdir $pathname, $callback->($status)
228 aio_readdir $pathname, $callback->($entries)
229 aio_readdirx $pathname, $flags, $callback->($entries, $flags)
230 IO::AIO::READDIR_DENTS IO::AIO::READDIR_DIRS_FIRST
231 IO::AIO::READDIR_STAT_ORDER IO::AIO::READDIR_FOUND_UNKNOWN
232 aio_load $path, $data, $callback->($status)
233 aio_copy $srcpath, $dstpath, $callback->($status)
234 aio_move $srcpath, $dstpath, $callback->($status)
235 aio_scandir $path, $maxreq, $callback->($dirs, $nondirs)
236 aio_rmtree $path, $callback->($status)
237 aio_sync $callback->($status)
238 aio_fsync $fh, $callback->($status)
239 aio_fdatasync $fh, $callback->($status)
240 aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status)
241 aio_pathsync $path, $callback->($status)
242 aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
243 aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
244 aio_group $callback->(...)
245 aio_nop $callback->()
246
247 $prev_pri = aioreq_pri [$pri]
248 aioreq_nice $pri_adjust
249
250 IO::AIO::poll_wait
251 IO::AIO::poll_cb
252 IO::AIO::poll
253 IO::AIO::flush
254 IO::AIO::max_poll_reqs $nreqs
255 IO::AIO::max_poll_time $seconds
256 IO::AIO::min_parallel $nthreads
257 IO::AIO::max_parallel $nthreads
258 IO::AIO::max_idle $nthreads
259 IO::AIO::max_outstanding $maxreqs
260 IO::AIO::nreqs
261 IO::AIO::nready
262 IO::AIO::npending
263
264 IO::AIO::sendfile $ofh, $ifh, $offset, $count
265 IO::AIO::fadvise $fh, $offset, $len, $advice
266 IO::AIO::mlockall $flags
267 IO::AIO::munlockall
223 268
224=head2 AIO REQUEST FUNCTIONS 269=head2 AIO REQUEST FUNCTIONS
225 270
226All the C<aio_*> calls are more or less thin wrappers around the syscall 271All the C<aio_*> calls are more or less thin wrappers around the syscall
227with the same name (sans C<aio_>). The arguments are similar or identical, 272with the same name (sans C<aio_>). The arguments are similar or identical,
381 426
382This call tries to make use of a native C<sendfile> syscall to provide 427This call tries to make use of a native C<sendfile> syscall to provide
383zero-copy operation. For this to work, C<$out_fh> should refer to a 428zero-copy operation. For this to work, C<$out_fh> should refer to a
384socket, and C<$in_fh> should refer to mmap'able file. 429socket, and C<$in_fh> should refer to mmap'able file.
385 430
386If the native sendfile call fails or is not implemented, it will be 431If a native sendfile cannot be found or it fails with C<ENOSYS>,
432C<ENOTSUP>, C<EOPNOTSUPP>, C<EAFNOSUPPORT>, C<EPROTOTYPE> or C<ENOTSOCK>,
387emulated, so you can call C<aio_sendfile> on any type of filehandle 433it will be emulated, so you can call C<aio_sendfile> on any type of
388regardless of the limitations of the operating system. 434filehandle regardless of the limitations of the operating system.
389 435
390Please note, however, that C<aio_sendfile> can read more bytes from 436Please note, however, that C<aio_sendfile> can read more bytes from
391C<$in_fh> than are written, and there is no way to find out how many 437C<$in_fh> than are written, and there is no way to find out how many
392bytes have been read from C<aio_sendfile> alone, as C<aio_sendfile> only 438bytes have been read from C<aio_sendfile> alone, as C<aio_sendfile> only
393provides the number of bytes written to C<$out_fh>. Only if the result 439provides the number of bytes written to C<$out_fh>. Only if the result
431 $_[0] and die "stat failed: $!"; 477 $_[0] and die "stat failed: $!";
432 print "size is ", -s _, "\n"; 478 print "size is ", -s _, "\n";
433 }; 479 };
434 480
435 481
482=item aio_statvfs $fh_or_path, $callback->($statvfs)
483
484Works like the POSIX C<statvfs> or C<fstatvfs> syscalls, depending on
485whether a file handle or path was passed.
486
487On success, the callback is passed a hash reference with the following
488members: C<bsize>, C<frsize>, C<blocks>, C<bfree>, C<bavail>, C<files>,
489C<ffree>, C<favail>, C<fsid>, C<flag> and C<namemax>. On failure, C<undef>
490is passed.
491
492The following POSIX IO::AIO::ST_* constants are defined: C<ST_RDONLY> and
493C<ST_NOSUID>.
494
495The following non-POSIX IO::AIO::ST_* flag masks are defined to
496their correct value when available, or to C<0> on systems that do
497not support them: C<ST_NODEV>, C<ST_NOEXEC>, C<ST_SYNCHRONOUS>,
498C<ST_MANDLOCK>, C<ST_WRITE>, C<ST_APPEND>, C<ST_IMMUTABLE>, C<ST_NOATIME>,
499C<ST_NODIRATIME> and C<ST_RELATIME>.
500
501Example: stat C</wd> and dump out the data if successful.
502
503 aio_statvfs "/wd", sub {
504 my $f = $_[0]
505 or die "statvfs: $!";
506
507 use Data::Dumper;
508 say Dumper $f;
509 };
510
511 # result:
512 {
513 bsize => 1024,
514 bfree => 4333064312,
515 blocks => 10253828096,
516 files => 2050765568,
517 flag => 4096,
518 favail => 2042092649,
519 bavail => 4333064312,
520 ffree => 2042092649,
521 namemax => 255,
522 frsize => 1024,
523 fsid => 1810
524 }
525
526
436=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status) 527=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
437 528
438Works like perl's C<utime> function (including the special case of $atime 529Works like perl's C<utime> function (including the special case of $atime
439and $mtime being undef). Fractional times are supported if the underlying 530and $mtime being undef). Fractional times are supported if the underlying
440syscalls support them. 531syscalls support them.
548The flags are a combination of the following constants, ORed together (the 639The flags are a combination of the following constants, ORed together (the
549flags will also be passed to the callback, possibly modified): 640flags will also be passed to the callback, possibly modified):
550 641
551=over 4 642=over 4
552 643
553=item AIO::READDIR_DENTS 644=item IO::AIO::READDIR_DENTS
554 645
555When this flag is off, then the callback gets an arrayref with of names 646When this flag is off, then the callback gets an arrayref with of names
556only (as with C<aio_readdir>), otherwise it gets an arrayref with 647only (as with C<aio_readdir>), otherwise it gets an arrayref with
557C<[$name, $inode, $type]> arrayrefs, each describing a single directory 648C<[$name, $type, $inode]> arrayrefs, each describing a single directory
558entry in more detail. 649entry in more detail.
559 650
560C<$name> is the name of the entry. 651C<$name> is the name of the entry.
561 652
562C<$inode> is the inode number (which might not be exact on systems with 64
563bit inode numbers and 32 bit perls). On systems that do not deliver the
564inode information, this will always be zero.
565
566C<$type> is one of the C<AIO::DT_xxx> constants: 653C<$type> is one of the C<IO::AIO::DT_xxx> constants:
567 654
568C<AIO::DT_UNKNOWN>, C<AIO::DT_FIFO>, C<AIO::DT_CHR>, C<AIO::DT_DIR>, 655C<IO::AIO::DT_UNKNOWN>, C<IO::AIO::DT_FIFO>, C<IO::AIO::DT_CHR>, C<IO::AIO::DT_DIR>,
569C<AIO::DT_BLK>, C<AIO::DT_REG>, C<AIO::DT_LNK>, C<AIO::DT_SOCK>, 656C<IO::AIO::DT_BLK>, C<IO::AIO::DT_REG>, C<IO::AIO::DT_LNK>, C<IO::AIO::DT_SOCK>,
570C<AIO::DT_WHT>. 657C<IO::AIO::DT_WHT>.
571 658
572C<AIO::DT_UNKNOWN> means just that: readdir does not know. If you need to 659C<IO::AIO::DT_UNKNOWN> means just that: readdir does not know. If you need to
573know, you have to run stat yourself. Also, for speed reasons, the C<$type> 660know, you have to run stat yourself. Also, for speed reasons, the C<$type>
574scalars are read-only: you can not modify them. 661scalars are read-only: you can not modify them.
575 662
663C<$inode> is the inode number (which might not be exact on systems with 64
664bit inode numbers and 32 bit perls). This field has unspecified content on
665systems that do not deliver the inode information.
666
576=item AIO::READDIR_DIRS_FIRST 667=item IO::AIO::READDIR_DIRS_FIRST
577 668
578When this flag is set, then the names will be returned in an order where 669When this flag is set, then the names will be returned in an order where
579likely directories come first. This is useful when you need to quickly 670likely directories come first. This is useful when you need to quickly
580find directories, or you want to find all directories while avoiding to 671find directories, or you want to find all directories while avoiding to
581stat() each entry. 672stat() each entry.
582 673
674If the system returns type information in readdir, then this is used
675to find directories directly. Otherwise, likely directories are files
676beginning with ".", or otherwise files with no dots, of which files with
677short names are tried first.
678
583=item AIO::READDIR_STAT_ORDER 679=item IO::AIO::READDIR_STAT_ORDER
584 680
585When this flag is set, then the names will be returned in an order 681When this flag is set, then the names will be returned in an order
586suitable for stat()'ing each one. That is, when you plan to stat() 682suitable for stat()'ing each one. That is, when you plan to stat()
587all files in the given directory, then the returned order will likely 683all files in the given directory, then the returned order will likely
588be fastest. 684be fastest.
589 685
590If both this flag and IO::READDIR_DIRS_FIRST are specified, then the 686If both this flag and C<IO::AIO::READDIR_DIRS_FIRST> are specified, then
591likely dirs come first, resulting in a less optimal stat order. 687the likely dirs come first, resulting in a less optimal stat order.
592 688
593=item AIO::READDIR_FOUND_UNKNOWN 689=item IO::AIO::READDIR_FOUND_UNKNOWN
594 690
595This flag should not be set when calling C<aio_readdirx>. Instead, it 691This flag should not be set when calling C<aio_readdirx>. Instead, it
596is being set by C<aio_readdirx>, when any of the C<$type>'s found were 692is being set by C<aio_readdirx>, when any of the C<$type>'s found were
597C<AIO::DT_UNKNOWN>. The absense of this flag therefore indicates that all 693C<IO::AIO::DT_UNKNOWN>. The absense of this flag therefore indicates that all
598C<$type>'s are known, which can be used to speed up some algorithms. 694C<$type>'s are known, which can be used to speed up some algorithms.
599 695
600=back 696=back
601 697
602 698
630 726
631=item aio_copy $srcpath, $dstpath, $callback->($status) 727=item aio_copy $srcpath, $dstpath, $callback->($status)
632 728
633Try to copy the I<file> (directories not supported as either source or 729Try to copy the I<file> (directories not supported as either source or
634destination) from C<$srcpath> to C<$dstpath> and call the callback with 730destination) from C<$srcpath> to C<$dstpath> and call the callback with
635the C<0> (error) or C<-1> ok. 731a status of C<0> (ok) or C<-1> (error, see C<$!>).
636 732
637This is a composite request that creates the destination file with 733This is a composite request that creates the destination file with
638mode 0200 and copies the contents of the source file into it using 734mode 0200 and copies the contents of the source file into it using
639C<aio_sendfile>, followed by restoring atime, mtime, access mode and 735C<aio_sendfile>, followed by restoring atime, mtime, access mode and
640uid/gid, in that order. 736uid/gid, in that order.
652 my $grp = aio_group $cb; 748 my $grp = aio_group $cb;
653 749
654 aioreq_pri $pri; 750 aioreq_pri $pri;
655 add $grp aio_open $src, O_RDONLY, 0, sub { 751 add $grp aio_open $src, O_RDONLY, 0, sub {
656 if (my $src_fh = $_[0]) { 752 if (my $src_fh = $_[0]) {
657 my @stat = stat $src_fh; # hmm, might bock over nfs? 753 my @stat = stat $src_fh; # hmm, might block over nfs?
658 754
659 aioreq_pri $pri; 755 aioreq_pri $pri;
660 add $grp aio_open $dst, O_CREAT | O_WRONLY | O_TRUNC, 0200, sub { 756 add $grp aio_open $dst, O_CREAT | O_WRONLY | O_TRUNC, 0200, sub {
661 if (my $dst_fh = $_[0]) { 757 if (my $dst_fh = $_[0]) {
662 aioreq_pri $pri; 758 aioreq_pri $pri;
709 805
710=item aio_move $srcpath, $dstpath, $callback->($status) 806=item aio_move $srcpath, $dstpath, $callback->($status)
711 807
712Try to move the I<file> (directories not supported as either source or 808Try to move the I<file> (directories not supported as either source or
713destination) from C<$srcpath> to C<$dstpath> and call the callback with 809destination) from C<$srcpath> to C<$dstpath> and call the callback with
714the C<0> (error) or C<-1> ok. 810a status of C<0> (ok) or C<-1> (error, see C<$!>).
715 811
716This is a composite request that tries to rename(2) the file first; if 812This is a composite request that tries to rename(2) the file first; if
717rename fails with C<EXDEV>, it copies the file with C<aio_copy> and, if 813rename fails with C<EXDEV>, it copies the file with C<aio_copy> and, if
718that is successful, unlinks the C<$srcpath>. 814that is successful, unlinks the C<$srcpath>.
719 815
770 866
771Implementation notes. 867Implementation notes.
772 868
773The C<aio_readdir> cannot be avoided, but C<stat()>'ing every entry can. 869The C<aio_readdir> cannot be avoided, but C<stat()>'ing every entry can.
774 870
871If readdir returns file type information, then this is used directly to
872find directories.
873
775After reading the directory, the modification time, size etc. of the 874Otherwise, after reading the directory, the modification time, size etc.
776directory before and after the readdir is checked, and if they match (and 875of the directory before and after the readdir is checked, and if they
777isn't the current time), the link count will be used to decide how many 876match (and isn't the current time), the link count will be used to decide
778entries are directories (if >= 2). Otherwise, no knowledge of the number 877how many entries are directories (if >= 2). Otherwise, no knowledge of the
779of subdirectories will be assumed. 878number of subdirectories will be assumed.
780 879
781Then entries will be sorted into likely directories (everything without 880Then entries will be sorted into likely directories a non-initial dot
782a non-initial dot currently) and likely non-directories (everything 881currently) and likely non-directories (see C<aio_readdirx>). Then every
783else). Then every entry plus an appended C</.> will be C<stat>'ed, 882entry plus an appended C</.> will be C<stat>'ed, likely directories first,
784likely directories first. If that succeeds, it assumes that the entry 883in order of their inode numbers. If that succeeds, it assumes that the
785is a directory or a symlink to directory (which will be checked 884entry is a directory or a symlink to directory (which will be checked
786seperately). This is often faster than stat'ing the entry itself because 885seperately). This is often faster than stat'ing the entry itself because
787filesystems might detect the type of the entry without reading the inode 886filesystems might detect the type of the entry without reading the inode
788data (e.g. ext2fs filetype feature). 887data (e.g. ext2fs filetype feature), even on systems that cannot return
888the filetype information on readdir.
789 889
790If the known number of directories (link count - 2) has been reached, the 890If the known number of directories (link count - 2) has been reached, the
791rest of the entries is assumed to be non-directories. 891rest of the entries is assumed to be non-directories.
792 892
793This only works with certainty on POSIX (= UNIX) filesystems, which 893This only works with certainty on POSIX (= UNIX) filesystems, which
831 # take the slow route if anything looks fishy 931 # take the slow route if anything looks fishy
832 if ($hash1 ne $hash2 or (stat _)[9] == $now) { 932 if ($hash1 ne $hash2 or (stat _)[9] == $now) {
833 $ndirs = -1; 933 $ndirs = -1;
834 } else { 934 } else {
835 # if nlink == 2, we are finished 935 # if nlink == 2, we are finished
836 # on non-posix-fs's, we rely on nlink < 2 936 # for non-posix-fs's, we rely on nlink < 2
837 $ndirs = (stat _)[3] - 2 937 $ndirs = (stat _)[3] - 2
838 or return $grp->result ([], $entries); 938 or return $grp->result ([], $entries);
839 } 939 }
840 940
841 # sort into likely dirs and likely nondirs
842 # dirs == files without ".", short entries first
843 $entries = [map $_->[0],
844 sort { $b->[1] cmp $a->[1] }
845 map [$_, sprintf "%s%04d", (/.\./ ? "1" : "0"), length],
846 @$entries];
847
848 my (@dirs, @nondirs); 941 my (@dirs, @nondirs);
849 942
850 my $statgrp = add $grp aio_group sub { 943 my $statgrp = add $grp aio_group sub {
851 $grp->result (\@dirs, \@nondirs); 944 $grp->result (\@dirs, \@nondirs);
852 }; 945 };
853 946
854 limit $statgrp $maxreq; 947 limit $statgrp $maxreq;
855 feed $statgrp sub { 948 feed $statgrp sub {
856 return unless @$entries; 949 return unless @$entries;
857 my $entry = pop @$entries; 950 my $entry = shift @$entries;
858 951
859 aioreq_pri $pri; 952 aioreq_pri $pri;
860 add $statgrp aio_stat "$path/$entry/.", sub { 953 add $statgrp aio_stat "$path/$entry/.", sub {
861 if ($_[0] < 0) { 954 if ($_[0] < 0) {
862 push @nondirs, $entry; 955 push @nondirs, $entry;
956(E.g. rename). This might not work on all operating systems or have any 1049(E.g. rename). This might not work on all operating systems or have any
957specific effect, but usually it makes sure that directory changes get 1050specific effect, but usually it makes sure that directory changes get
958written to disc. It works for anything that can be opened for read-only, 1051written to disc. It works for anything that can be opened for read-only,
959not just directories. 1052not just directories.
960 1053
1054Future versions of this function might fall back to other methods when
1055C<fsync> on the directory fails (such as calling C<sync>).
1056
961Passes C<0> when everything went ok, and C<-1> on error. 1057Passes C<0> when everything went ok, and C<-1> on error.
962 1058
963=cut 1059=cut
964 1060
965sub aio_pathsync($;$) { 1061sub aio_pathsync($;$) {
985 }; 1081 };
986 1082
987 $grp 1083 $grp
988} 1084}
989 1085
1086=item aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
1087
1088This is a rather advanced IO::AIO call, which only works on mmap(2)ed
1089scalars (see the L<Sys::Mmap> or L<Mmap> modules for details on this, note
1090that the scalar must only be modified in-place while an aio operation is
1091pending on it).
1092
1093It calls the C<msync> function of your OS, if available, with the memory
1094area starting at C<$offset> in the string and ending C<$length> bytes
1095later. If C<$length> is negative, counts from the end, and if C<$length>
1096is C<undef>, then it goes till the end of the string. The flags can be
1097a combination of C<IO::AIO::MS_ASYNC>, C<IO::AIO::MS_INVALIDATE> and
1098C<IO::AIO::MS_SYNC>.
1099
1100=item aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
1101
1102This is a rather advanced IO::AIO call, which works best on mmap(2)ed
1103scalars.
1104
1105It touches (reads or writes) all memory pages in the specified
1106range inside the scalar. All caveats and parameters are the same
1107as for C<aio_msync>, above, except for flags, which must be either
1108C<0> (which reads all pages and ensures they are instantiated) or
1109C<IO::AIO::MT_MODIFY>, which modifies the memory page s(by reading and
1110writing an octet from it, which dirties the page).
1111
990=item aio_group $callback->(...) 1112=item aio_group $callback->(...)
991 1113
992This is a very special aio request: Instead of doing something, it is a 1114This is a very special aio request: Instead of doing something, it is a
993container for other aio requests, which is useful if you want to bundle 1115container for other aio requests, which is useful if you want to bundle
994many requests into a single, composite, request with a definite callback 1116many requests into a single, composite, request with a definite callback
1043=item cancel $req 1165=item cancel $req
1044 1166
1045Cancels the request, if possible. Has the effect of skipping execution 1167Cancels the request, if possible. Has the effect of skipping execution
1046when entering the B<execute> state and skipping calling the callback when 1168when entering the B<execute> state and skipping calling the callback when
1047entering the the B<result> state, but will leave the request otherwise 1169entering the the B<result> state, but will leave the request otherwise
1048untouched. That means that requests that currently execute will not be 1170untouched (with the exception of readdir). That means that requests that
1049stopped and resources held by the request will not be freed prematurely. 1171currently execute will not be stopped and resources held by the request
1172will not be freed prematurely.
1050 1173
1051=item cb $req $callback->(...) 1174=item cb $req $callback->(...)
1052 1175
1053Replace (or simply set) the callback registered to the request. 1176Replace (or simply set) the callback registered to the request.
1054 1177
1127 1250
1128=item $grp->cancel_subs 1251=item $grp->cancel_subs
1129 1252
1130Cancel all subrequests and clears any feeder, but not the group request 1253Cancel all subrequests and clears any feeder, but not the group request
1131itself. Useful when you queued a lot of events but got a result early. 1254itself. Useful when you queued a lot of events but got a result early.
1255
1256The group request will finish normally (you cannot add requests to the
1257group).
1132 1258
1133=item $grp->result (...) 1259=item $grp->result (...)
1134 1260
1135Set the result value(s) that will be passed to the group callback when all 1261Set the result value(s) that will be passed to the group callback when all
1136subrequests have finished and set the groups errno to the current value 1262subrequests have finished and set the groups errno to the current value
1205=over 4 1331=over 4
1206 1332
1207=item $fileno = IO::AIO::poll_fileno 1333=item $fileno = IO::AIO::poll_fileno
1208 1334
1209Return the I<request result pipe file descriptor>. This filehandle must be 1335Return the I<request result pipe file descriptor>. This filehandle must be
1210polled for reading by some mechanism outside this module (e.g. Event or 1336polled for reading by some mechanism outside this module (e.g. EV, Glib,
1211select, see below or the SYNOPSIS). If the pipe becomes readable you have 1337select and so on, see below or the SYNOPSIS). If the pipe becomes readable
1212to call C<poll_cb> to check the results. 1338you have to call C<poll_cb> to check the results.
1213 1339
1214See C<poll_cb> for an example. 1340See C<poll_cb> for an example.
1215 1341
1216=item IO::AIO::poll_cb 1342=item IO::AIO::poll_cb
1217 1343
1224If not all requests were processed for whatever reason, the filehandle 1350If not all requests were processed for whatever reason, the filehandle
1225will still be ready when C<poll_cb> returns, so normally you don't have to 1351will still be ready when C<poll_cb> returns, so normally you don't have to
1226do anything special to have it called later. 1352do anything special to have it called later.
1227 1353
1228Example: Install an Event watcher that automatically calls 1354Example: Install an Event watcher that automatically calls
1229IO::AIO::poll_cb with high priority: 1355IO::AIO::poll_cb with high priority (more examples can be found in the
1356SYNOPSIS section, at the top of this document):
1230 1357
1231 Event->io (fd => IO::AIO::poll_fileno, 1358 Event->io (fd => IO::AIO::poll_fileno,
1232 poll => 'r', async => 1, 1359 poll => 'r', async => 1,
1233 cb => \&IO::AIO::poll_cb); 1360 cb => \&IO::AIO::poll_cb);
1361
1362=item IO::AIO::poll_wait
1363
1364If there are any outstanding requests and none of them in the result
1365phase, wait till the result filehandle becomes ready for reading (simply
1366does a C<select> on the filehandle. This is useful if you want to
1367synchronously wait for some requests to finish).
1368
1369See C<nreqs> for an example.
1370
1371=item IO::AIO::poll
1372
1373Waits until some requests have been handled.
1374
1375Returns the number of requests processed, but is otherwise strictly
1376equivalent to:
1377
1378 IO::AIO::poll_wait, IO::AIO::poll_cb
1379
1380=item IO::AIO::flush
1381
1382Wait till all outstanding AIO requests have been handled.
1383
1384Strictly equivalent to:
1385
1386 IO::AIO::poll_wait, IO::AIO::poll_cb
1387 while IO::AIO::nreqs;
1234 1388
1235=item IO::AIO::max_poll_reqs $nreqs 1389=item IO::AIO::max_poll_reqs $nreqs
1236 1390
1237=item IO::AIO::max_poll_time $seconds 1391=item IO::AIO::max_poll_time $seconds
1238 1392
1263 # use a low priority so other tasks have priority 1417 # use a low priority so other tasks have priority
1264 Event->io (fd => IO::AIO::poll_fileno, 1418 Event->io (fd => IO::AIO::poll_fileno,
1265 poll => 'r', nice => 1, 1419 poll => 'r', nice => 1,
1266 cb => &IO::AIO::poll_cb); 1420 cb => &IO::AIO::poll_cb);
1267 1421
1268=item IO::AIO::poll_wait
1269
1270If there are any outstanding requests and none of them in the result
1271phase, wait till the result filehandle becomes ready for reading (simply
1272does a C<select> on the filehandle. This is useful if you want to
1273synchronously wait for some requests to finish).
1274
1275See C<nreqs> for an example.
1276
1277=item IO::AIO::poll
1278
1279Waits until some requests have been handled.
1280
1281Returns the number of requests processed, but is otherwise strictly
1282equivalent to:
1283
1284 IO::AIO::poll_wait, IO::AIO::poll_cb
1285
1286=item IO::AIO::flush
1287
1288Wait till all outstanding AIO requests have been handled.
1289
1290Strictly equivalent to:
1291
1292 IO::AIO::poll_wait, IO::AIO::poll_cb
1293 while IO::AIO::nreqs;
1294
1295=back 1422=back
1296 1423
1297=head3 CONTROLLING THE NUMBER OF THREADS 1424=head3 CONTROLLING THE NUMBER OF THREADS
1298 1425
1299=over 1426=over
1391Returns the number of requests currently in the pending state (executed, 1518Returns the number of requests currently in the pending state (executed,
1392but not yet processed by poll_cb). 1519but not yet processed by poll_cb).
1393 1520
1394=back 1521=back
1395 1522
1523=head3 MISCELLANEOUS FUNCTIONS
1524
1525IO::AIO implements some functions that might be useful, but are not
1526asynchronous.
1527
1528=over 4
1529
1530=item IO::AIO::sendfile $ofh, $ifh, $offset, $count
1531
1532Calls the C<eio_sendfile_sync> function, which is like C<aio_sendfile>,
1533but is blocking (this makes most sense if you know the input data is
1534likely cached already and the output filehandle is set to non-blocking
1535operations).
1536
1537Returns the number of bytes copied, or C<-1> on error.
1538
1539=item IO::AIO::fadvise $fh, $offset, $len, $advice
1540
1541Simply calls the C<posix_fadvise> function (see it's
1542manpage for details). The following advice constants are
1543avaiable: C<IO::AIO::FADV_NORMAL>, C<IO::AIO::FADV_SEQUENTIAL>,
1544C<IO::AIO::FADV_RANDOM>, C<IO::AIO::FADV_NOREUSE>,
1545C<IO::AIO::FADV_WILLNEED>, C<IO::AIO::FADV_DONTNEED>.
1546
1547On systems that do not implement C<posix_fadvise>, this function returns
1548ENOSYS, otherwise the return value of C<posix_fadvise>.
1549
1550=item IO::AIO::mlockall $flags
1551
1552Calls the C<mlockall> function with the given C<$flags> (a combination of
1553C<IO::AIO::MCL_CURRENT> and C<IO::AIO::MCL__FUTURE>).
1554
1555On systems that do not implement C<mlockall>, this function returns
1556ENOSYS, otherwise the return value of C<mlockall>.
1557
1558=item IO::AIO::munlockall
1559
1560Calls the C<munlockall> function.
1561
1562On systems that do not implement C<munlockall>, this function returns
1563ENOSYS, otherwise the return value of C<munlockall>.
1564
1565=back
1566
1396=cut 1567=cut
1397 1568
1398min_parallel 8; 1569min_parallel 8;
1399 1570
1400END { flush } 1571END { flush }
1401 1572
14021; 15731;
1574
1575=head1 EVENT LOOP INTEGRATION
1576
1577It is recommended to use L<AnyEvent::AIO> to integrate IO::AIO
1578automatically into many event loops:
1579
1580 # AnyEvent integration (EV, Event, Glib, Tk, POE, urxvt, pureperl...)
1581 use AnyEvent::AIO;
1582
1583You can also integrate IO::AIO manually into many event loops, here are
1584some examples of how to do this:
1585
1586 # EV integration
1587 my $aio_w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb;
1588
1589 # Event integration
1590 Event->io (fd => IO::AIO::poll_fileno,
1591 poll => 'r',
1592 cb => \&IO::AIO::poll_cb);
1593
1594 # Glib/Gtk2 integration
1595 add_watch Glib::IO IO::AIO::poll_fileno,
1596 in => sub { IO::AIO::poll_cb; 1 };
1597
1598 # Tk integration
1599 Tk::Event::IO->fileevent (IO::AIO::poll_fileno, "",
1600 readable => \&IO::AIO::poll_cb);
1601
1602 # Danga::Socket integration
1603 Danga::Socket->AddOtherFds (IO::AIO::poll_fileno =>
1604 \&IO::AIO::poll_cb);
1403 1605
1404=head2 FORK BEHAVIOUR 1606=head2 FORK BEHAVIOUR
1405 1607
1406This module should do "the right thing" when the process using it forks: 1608This module should do "the right thing" when the process using it forks:
1407 1609

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