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Comparing IO-AIO/AIO.pm (file contents):
Revision 1.219 by root, Tue Mar 27 18:54:45 2012 UTC vs.
Revision 1.264 by root, Mon Jul 18 07:48:01 2016 UTC

68=head2 EXAMPLE 68=head2 EXAMPLE
69 69
70This is a simple example that uses the EV module and loads 70This is a simple example that uses the EV module and loads
71F</etc/passwd> asynchronously: 71F</etc/passwd> asynchronously:
72 72
73 use Fcntl;
74 use EV; 73 use EV;
75 use IO::AIO; 74 use IO::AIO;
76 75
77 # register the IO::AIO callback with EV 76 # register the IO::AIO callback with EV
78 my $aio_w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb; 77 my $aio_w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb;
95 94
96 # file contents now in $contents 95 # file contents now in $contents
97 print $contents; 96 print $contents;
98 97
99 # exit event loop and program 98 # exit event loop and program
100 EV::unloop; 99 EV::break;
101 }; 100 };
102 }; 101 };
103 102
104 # possibly queue up other requests, or open GUI windows, 103 # possibly queue up other requests, or open GUI windows,
105 # check for sockets etc. etc. 104 # check for sockets etc. etc.
106 105
107 # process events as long as there are some: 106 # process events as long as there are some:
108 EV::loop; 107 EV::run;
109 108
110=head1 REQUEST ANATOMY AND LIFETIME 109=head1 REQUEST ANATOMY AND LIFETIME
111 110
112Every C<aio_*> function creates a request. which is a C data structure not 111Every C<aio_*> function creates a request. which is a C data structure not
113directly visible to Perl. 112directly visible to Perl.
168use common::sense; 167use common::sense;
169 168
170use base 'Exporter'; 169use base 'Exporter';
171 170
172BEGIN { 171BEGIN {
173 our $VERSION = '4.12'; 172 our $VERSION = 4.34;
174 173
175 our @AIO_REQ = qw(aio_sendfile aio_read aio_write aio_open aio_close 174 our @AIO_REQ = qw(aio_sendfile aio_seek aio_read aio_write aio_open aio_close
176 aio_stat aio_lstat aio_unlink aio_rmdir aio_readdir aio_readdirx 175 aio_stat aio_lstat aio_unlink aio_rmdir aio_readdir aio_readdirx
177 aio_scandir aio_symlink aio_readlink aio_realpath aio_sync 176 aio_scandir aio_symlink aio_readlink aio_realpath aio_fcntl aio_ioctl
178 aio_fsync aio_syncfs aio_fdatasync aio_sync_file_range aio_fallocate 177 aio_sync aio_fsync aio_syncfs aio_fdatasync aio_sync_file_range
179 aio_pathsync aio_readahead 178 aio_pathsync aio_readahead aio_fiemap aio_allocate
180 aio_rename aio_link aio_move aio_copy aio_group 179 aio_rename aio_link aio_move aio_copy aio_group
181 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
182 aio_chmod aio_utime aio_truncate 181 aio_chmod aio_utime aio_truncate
183 aio_msync aio_mtouch aio_mlock aio_mlockall 182 aio_msync aio_mtouch aio_mlock aio_mlockall
184 aio_statvfs 183 aio_statvfs
202 201
203=head1 FUNCTIONS 202=head1 FUNCTIONS
204 203
205=head2 QUICK OVERVIEW 204=head2 QUICK OVERVIEW
206 205
207This section simply lists the prototypes of the most important functions 206This section simply lists the prototypes most of the functions for
208for quick reference. See the following sections for function-by-function 207quick reference. See the following sections for function-by-function
209documentation. 208documentation.
210 209
211 aio_wd $pathname, $callback->($wd) 210 aio_wd $pathname, $callback->($wd)
212 aio_open $pathname, $flags, $mode, $callback->($fh) 211 aio_open $pathname, $flags, $mode, $callback->($fh)
213 aio_close $fh, $callback->($status) 212 aio_close $fh, $callback->($status)
213 aio_seek $fh,$offset,$whence, $callback->($offs)
214 aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval) 214 aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
215 aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval) 215 aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
216 aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval) 216 aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval)
217 aio_readahead $fh,$offset,$length, $callback->($retval) 217 aio_readahead $fh,$offset,$length, $callback->($retval)
218 aio_stat $fh_or_path, $callback->($status) 218 aio_stat $fh_or_path, $callback->($status)
219 aio_lstat $fh, $callback->($status) 219 aio_lstat $fh, $callback->($status)
220 aio_statvfs $fh_or_path, $callback->($statvfs) 220 aio_statvfs $fh_or_path, $callback->($statvfs)
221 aio_utime $fh_or_path, $atime, $mtime, $callback->($status) 221 aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
222 aio_chown $fh_or_path, $uid, $gid, $callback->($status) 222 aio_chown $fh_or_path, $uid, $gid, $callback->($status)
223 aio_chmod $fh_or_path, $mode, $callback->($status)
223 aio_truncate $fh_or_path, $offset, $callback->($status) 224 aio_truncate $fh_or_path, $offset, $callback->($status)
224 aio_chmod $fh_or_path, $mode, $callback->($status) 225 aio_allocate $fh, $mode, $offset, $len, $callback->($status)
226 aio_fiemap $fh, $start, $length, $flags, $count, $cb->(\@extents)
225 aio_unlink $pathname, $callback->($status) 227 aio_unlink $pathname, $callback->($status)
226 aio_mknod $pathname, $mode, $dev, $callback->($status) 228 aio_mknod $pathname, $mode, $dev, $callback->($status)
227 aio_link $srcpath, $dstpath, $callback->($status) 229 aio_link $srcpath, $dstpath, $callback->($status)
228 aio_symlink $srcpath, $dstpath, $callback->($status) 230 aio_symlink $srcpath, $dstpath, $callback->($status)
229 aio_readlink $pathname, $callback->($link) 231 aio_readlink $pathname, $callback->($link)
230 aio_realpath $pathname, $callback->($link) 232 aio_realpath $pathname, $callback->($path)
231 aio_rename $srcpath, $dstpath, $callback->($status) 233 aio_rename $srcpath, $dstpath, $callback->($status)
232 aio_mkdir $pathname, $mode, $callback->($status) 234 aio_mkdir $pathname, $mode, $callback->($status)
233 aio_rmdir $pathname, $callback->($status) 235 aio_rmdir $pathname, $callback->($status)
234 aio_readdir $pathname, $callback->($entries) 236 aio_readdir $pathname, $callback->($entries)
235 aio_readdirx $pathname, $flags, $callback->($entries, $flags) 237 aio_readdirx $pathname, $flags, $callback->($entries, $flags)
238 aio_scandir $pathname, $maxreq, $callback->($dirs, $nondirs) 240 aio_scandir $pathname, $maxreq, $callback->($dirs, $nondirs)
239 aio_load $pathname, $data, $callback->($status) 241 aio_load $pathname, $data, $callback->($status)
240 aio_copy $srcpath, $dstpath, $callback->($status) 242 aio_copy $srcpath, $dstpath, $callback->($status)
241 aio_move $srcpath, $dstpath, $callback->($status) 243 aio_move $srcpath, $dstpath, $callback->($status)
242 aio_rmtree $pathname, $callback->($status) 244 aio_rmtree $pathname, $callback->($status)
245 aio_fcntl $fh, $cmd, $arg, $callback->($status)
246 aio_ioctl $fh, $request, $buf, $callback->($status)
243 aio_sync $callback->($status) 247 aio_sync $callback->($status)
244 aio_syncfs $fh, $callback->($status) 248 aio_syncfs $fh, $callback->($status)
245 aio_fsync $fh, $callback->($status) 249 aio_fsync $fh, $callback->($status)
246 aio_fdatasync $fh, $callback->($status) 250 aio_fdatasync $fh, $callback->($status)
247 aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status) 251 aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status)
271 IO::AIO::nready 275 IO::AIO::nready
272 IO::AIO::npending 276 IO::AIO::npending
273 277
274 IO::AIO::sendfile $ofh, $ifh, $offset, $count 278 IO::AIO::sendfile $ofh, $ifh, $offset, $count
275 IO::AIO::fadvise $fh, $offset, $len, $advice 279 IO::AIO::fadvise $fh, $offset, $len, $advice
280 IO::AIO::mmap $scalar, $length, $prot, $flags[, $fh[, $offset]]
281 IO::AIO::munmap $scalar
276 IO::AIO::madvise $scalar, $offset, $length, $advice 282 IO::AIO::madvise $scalar, $offset, $length, $advice
277 IO::AIO::mprotect $scalar, $offset, $length, $protect 283 IO::AIO::mprotect $scalar, $offset, $length, $protect
278 IO::AIO::munlock $scalar, $offset = 0, $length = undef 284 IO::AIO::munlock $scalar, $offset = 0, $length = undef
279 IO::AIO::munlockall 285 IO::AIO::munlockall
280 286
357 363
358 364
359=item aio_open $pathname, $flags, $mode, $callback->($fh) 365=item aio_open $pathname, $flags, $mode, $callback->($fh)
360 366
361Asynchronously open or create a file and call the callback with a newly 367Asynchronously open or create a file and call the callback with a newly
362created filehandle for the file. 368created filehandle for the file (or C<undef> in case of an error).
363 369
364The pathname passed to C<aio_open> must be absolute. See API NOTES, above, 370The pathname passed to C<aio_open> must be absolute. See API NOTES, above,
365for an explanation. 371for an explanation.
366 372
367The C<$flags> argument is a bitmask. See the C<Fcntl> module for a 373The C<$flags> argument is a bitmask. See the C<Fcntl> module for a
390following POSIX and non-POSIX constants are available (missing ones on 396following POSIX and non-POSIX constants are available (missing ones on
391your system are, as usual, C<0>): 397your system are, as usual, C<0>):
392 398
393C<O_ASYNC>, C<O_DIRECT>, C<O_NOATIME>, C<O_CLOEXEC>, C<O_NOCTTY>, C<O_NOFOLLOW>, 399C<O_ASYNC>, C<O_DIRECT>, C<O_NOATIME>, C<O_CLOEXEC>, C<O_NOCTTY>, C<O_NOFOLLOW>,
394C<O_NONBLOCK>, C<O_EXEC>, C<O_SEARCH>, C<O_DIRECTORY>, C<O_DSYNC>, 400C<O_NONBLOCK>, C<O_EXEC>, C<O_SEARCH>, C<O_DIRECTORY>, C<O_DSYNC>,
395C<O_RSYNC>, C<O_SYNC> and C<O_TTY_INIT>. 401C<O_RSYNC>, C<O_SYNC>, C<O_PATH>, C<O_TMPFILE>, and C<O_TTY_INIT>.
396 402
397 403
398=item aio_close $fh, $callback->($status) 404=item aio_close $fh, $callback->($status)
399 405
400Asynchronously close a file and call the callback with the result 406Asynchronously close a file and call the callback with the result
409 415
410Or in other words: the file descriptor will be closed, but it will not be 416Or in other words: the file descriptor will be closed, but it will not be
411free for reuse until the perl filehandle is closed. 417free for reuse until the perl filehandle is closed.
412 418
413=cut 419=cut
420
421=item aio_seek $fh, $offset, $whence, $callback->($offs)
422
423Seeks the filehandle to the new C<$offset>, similarly to perl's
424C<sysseek>. The C<$whence> can use the traditional values (C<0> for
425C<IO::AIO::SEEK_SET>, C<1> for C<IO::AIO::SEEK_CUR> or C<2> for
426C<IO::AIO::SEEK_END>).
427
428The resulting absolute offset will be passed to the callback, or C<-1> in
429case of an error.
430
431In theory, the C<$whence> constants could be different than the
432corresponding values from L<Fcntl>, but perl guarantees they are the same,
433so don't panic.
434
435As a GNU/Linux (and maybe Solaris) extension, also the constants
436C<IO::AIO::SEEK_DATA> and C<IO::AIO::SEEK_HOLE> are available, if they
437could be found. No guarantees about suitability for use in C<aio_seek> or
438Perl's C<sysseek> can be made though, although I would naively assume they
439"just work".
414 440
415=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval) 441=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
416 442
417=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval) 443=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
418 444
484As native sendfile syscalls (as practically any non-POSIX interface hacked 510As native sendfile syscalls (as practically any non-POSIX interface hacked
485together in a hurry to improve benchmark numbers) tend to be rather buggy 511together in a hurry to improve benchmark numbers) tend to be rather buggy
486on many systems, this implementation tries to work around some known bugs 512on many systems, this implementation tries to work around some known bugs
487in Linux and FreeBSD kernels (probably others, too), but that might fail, 513in Linux and FreeBSD kernels (probably others, too), but that might fail,
488so you really really should check the return value of C<aio_sendfile> - 514so you really really should check the return value of C<aio_sendfile> -
489fewre bytes than expected might have been transferred. 515fewer bytes than expected might have been transferred.
490 516
491 517
492=item aio_readahead $fh,$offset,$length, $callback->($retval) 518=item aio_readahead $fh,$offset,$length, $callback->($retval)
493 519
494C<aio_readahead> populates the page cache with data from a file so that 520C<aio_readahead> populates the page cache with data from a file so that
498whole pages, so that offset is effectively rounded down to a page boundary 524whole pages, so that offset is effectively rounded down to a page boundary
499and bytes are read up to the next page boundary greater than or equal to 525and bytes are read up to the next page boundary greater than or equal to
500(off-set+length). C<aio_readahead> does not read beyond the end of the 526(off-set+length). C<aio_readahead> does not read beyond the end of the
501file. The current file offset of the file is left unchanged. 527file. The current file offset of the file is left unchanged.
502 528
503If that syscall doesn't exist (likely if your OS isn't Linux) it will be 529If that syscall doesn't exist (likely if your kernel isn't Linux) it will
504emulated by simply reading the data, which would have a similar effect. 530be emulated by simply reading the data, which would have a similar effect.
505 531
506 532
507=item aio_stat $fh_or_path, $callback->($status) 533=item aio_stat $fh_or_path, $callback->($status)
508 534
509=item aio_lstat $fh, $callback->($status) 535=item aio_lstat $fh, $callback->($status)
578 namemax => 255, 604 namemax => 255,
579 frsize => 1024, 605 frsize => 1024,
580 fsid => 1810 606 fsid => 1810
581 } 607 }
582 608
609Here is a (likely partial - send me updates!) list of fsid values used by
610Linux - it is safe to hardcode these when C<$^O> is C<linux>:
611
612 0x0000adf5 adfs
613 0x0000adff affs
614 0x5346414f afs
615 0x09041934 anon-inode filesystem
616 0x00000187 autofs
617 0x42465331 befs
618 0x1badface bfs
619 0x42494e4d binfmt_misc
620 0x9123683e btrfs
621 0x0027e0eb cgroupfs
622 0xff534d42 cifs
623 0x73757245 coda
624 0x012ff7b7 coh
625 0x28cd3d45 cramfs
626 0x453dcd28 cramfs-wend (wrong endianness)
627 0x64626720 debugfs
628 0x00001373 devfs
629 0x00001cd1 devpts
630 0x0000f15f ecryptfs
631 0x00414a53 efs
632 0x0000137d ext
633 0x0000ef53 ext2/ext3/ext4
634 0x0000ef51 ext2
635 0xf2f52010 f2fs
636 0x00004006 fat
637 0x65735546 fuseblk
638 0x65735543 fusectl
639 0x0bad1dea futexfs
640 0x01161970 gfs2
641 0x47504653 gpfs
642 0x00004244 hfs
643 0xf995e849 hpfs
644 0x00c0ffee hostfs
645 0x958458f6 hugetlbfs
646 0x2bad1dea inotifyfs
647 0x00009660 isofs
648 0x000072b6 jffs2
649 0x3153464a jfs
650 0x6b414653 k-afs
651 0x0bd00bd0 lustre
652 0x0000137f minix
653 0x0000138f minix 30 char names
654 0x00002468 minix v2
655 0x00002478 minix v2 30 char names
656 0x00004d5a minix v3
657 0x19800202 mqueue
658 0x00004d44 msdos
659 0x0000564c novell
660 0x00006969 nfs
661 0x6e667364 nfsd
662 0x00003434 nilfs
663 0x5346544e ntfs
664 0x00009fa1 openprom
665 0x7461636F ocfs2
666 0x00009fa0 proc
667 0x6165676c pstorefs
668 0x0000002f qnx4
669 0x68191122 qnx6
670 0x858458f6 ramfs
671 0x52654973 reiserfs
672 0x00007275 romfs
673 0x67596969 rpc_pipefs
674 0x73636673 securityfs
675 0xf97cff8c selinux
676 0x0000517b smb
677 0x534f434b sockfs
678 0x73717368 squashfs
679 0x62656572 sysfs
680 0x012ff7b6 sysv2
681 0x012ff7b5 sysv4
682 0x01021994 tmpfs
683 0x15013346 udf
684 0x00011954 ufs
685 0x54190100 ufs byteswapped
686 0x00009fa2 usbdevfs
687 0x01021997 v9fs
688 0xa501fcf5 vxfs
689 0xabba1974 xenfs
690 0x012ff7b4 xenix
691 0x58465342 xfs
692 0x012fd16d xia
583 693
584=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status) 694=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
585 695
586Works like perl's C<utime> function (including the special case of $atime 696Works like perl's C<utime> function (including the special case of $atime
587and $mtime being undef). Fractional times are supported if the underlying 697and $mtime being undef). Fractional times are supported if the underlying
615=item aio_truncate $fh_or_path, $offset, $callback->($status) 725=item aio_truncate $fh_or_path, $offset, $callback->($status)
616 726
617Works like truncate(2) or ftruncate(2). 727Works like truncate(2) or ftruncate(2).
618 728
619 729
730=item aio_allocate $fh, $mode, $offset, $len, $callback->($status)
731
732Allocates or frees disk space according to the C<$mode> argument. See the
733linux C<fallocate> documentation for details.
734
735C<$mode> is usually C<0> or C<IO::AIO::FALLOC_FL_KEEP_SIZE> to allocate
736space, or C<IO::AIO::FALLOC_FL_PUNCH_HOLE | IO::AIO::FALLOC_FL_KEEP_SIZE>,
737to deallocate a file range.
738
739IO::AIO also supports C<FALLOC_FL_COLLAPSE_RANGE>, to remove a range
740(without leaving a hole) and C<FALLOC_FL_ZERO_RANGE>, to zero a range (see
741your L<fallocate(2)> manpage).
742
743The file system block size used by C<fallocate> is presumably the
744C<f_bsize> returned by C<statvfs>.
745
746If C<fallocate> isn't available or cannot be emulated (currently no
747emulation will be attempted), passes C<-1> and sets C<$!> to C<ENOSYS>.
748
749
620=item aio_chmod $fh_or_path, $mode, $callback->($status) 750=item aio_chmod $fh_or_path, $mode, $callback->($status)
621 751
622Works like perl's C<chmod> function. 752Works like perl's C<chmod> function.
623 753
624 754
661 791
662 792
663=item aio_realpath $pathname, $callback->($path) 793=item aio_realpath $pathname, $callback->($path)
664 794
665Asynchronously make the path absolute and resolve any symlinks in 795Asynchronously make the path absolute and resolve any symlinks in
666C<$path>. The resulting path only consists of directories (Same as 796C<$path>. The resulting path only consists of directories (same as
667L<Cwd::realpath>). 797L<Cwd::realpath>).
668 798
669This request can be used to get the absolute path of the current working 799This request can be used to get the absolute path of the current working
670directory by passing it a path of F<.> (a single dot). 800directory by passing it a path of F<.> (a single dot).
671 801
672 802
673=item aio_rename $srcpath, $dstpath, $callback->($status) 803=item aio_rename $srcpath, $dstpath, $callback->($status)
674 804
675Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as 805Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as
676rename(2) and call the callback with the result code. 806rename(2) and call the callback with the result code.
807
808On systems that support the AIO::WD working directory abstraction
809natively, the case C<[$wd, "."]> as C<$srcpath> is specialcased - instead
810of failing, C<rename> is called on the absolute path of C<$wd>.
677 811
678 812
679=item aio_mkdir $pathname, $mode, $callback->($status) 813=item aio_mkdir $pathname, $mode, $callback->($status)
680 814
681Asynchronously mkdir (create) a directory and call the callback with 815Asynchronously mkdir (create) a directory and call the callback with
685 819
686=item aio_rmdir $pathname, $callback->($status) 820=item aio_rmdir $pathname, $callback->($status)
687 821
688Asynchronously rmdir (delete) a directory and call the callback with the 822Asynchronously rmdir (delete) a directory and call the callback with the
689result code. 823result code.
824
825On systems that support the AIO::WD working directory abstraction
826natively, the case C<[$wd, "."]> is specialcased - instead of failing,
827C<rmdir> is called on the absolute path of C<$wd>.
690 828
691 829
692=item aio_readdir $pathname, $callback->($entries) 830=item aio_readdir $pathname, $callback->($entries)
693 831
694Unlike the POSIX call of the same name, C<aio_readdir> reads an entire 832Unlike the POSIX call of the same name, C<aio_readdir> reads an entire
1059} 1197}
1060 1198
1061=item aio_rmtree $pathname, $callback->($status) 1199=item aio_rmtree $pathname, $callback->($status)
1062 1200
1063Delete a directory tree starting (and including) C<$path>, return the 1201Delete a directory tree starting (and including) C<$path>, return the
1064status of the final C<rmdir> only. This is a composite request that 1202status of the final C<rmdir> only. This is a composite request that
1065uses C<aio_scandir> to recurse into and rmdir directories, and unlink 1203uses C<aio_scandir> to recurse into and rmdir directories, and unlink
1066everything else. 1204everything else.
1067 1205
1068=cut 1206=cut
1069 1207
1090 add $grp $dirgrp; 1228 add $grp $dirgrp;
1091 }; 1229 };
1092 1230
1093 $grp 1231 $grp
1094} 1232}
1233
1234=item aio_fcntl $fh, $cmd, $arg, $callback->($status)
1235
1236=item aio_ioctl $fh, $request, $buf, $callback->($status)
1237
1238These work just like the C<fcntl> and C<ioctl> built-in functions, except
1239they execute asynchronously and pass the return value to the callback.
1240
1241Both calls can be used for a lot of things, some of which make more sense
1242to run asynchronously in their own thread, while some others make less
1243sense. For example, calls that block waiting for external events, such
1244as locking, will also lock down an I/O thread while it is waiting, which
1245can deadlock the whole I/O system. At the same time, there might be no
1246alternative to using a thread to wait.
1247
1248So in general, you should only use these calls for things that do
1249(filesystem) I/O, not for things that wait for other events (network,
1250other processes), although if you are careful and know what you are doing,
1251you still can.
1252
1253The following constants are available (missing ones are, as usual C<0>):
1254
1255C<FIFREEZE>, C<FITHAW>, C<FITRIM>, C<FICLONE>, C<FICLONERANGE>, C<FIDEDUPERANGE>.
1256
1257C<FS_IOC_GETFLAGS>, C<FS_IOC_SETFLAGS>, C<FS_IOC_GETVERSION>, C<FS_IOC_SETVERSION>,
1258C<FS_IOC_FIEMAP>.
1259
1260C<FS_IOC_FSGETXATTR>, C<FS_IOC_FSSETXATTR>, C<FS_IOC_SET_ENCRYPTION_POLICY>,
1261C<FS_IOC_GET_ENCRYPTION_PWSALT>, C<FS_IOC_GET_ENCRYPTION_POLICY>, C<FS_KEY_DESCRIPTOR_SIZE>.
1262
1263C<FS_SECRM_FL>, C<FS_UNRM_FL>, C<FS_COMPR_FL>, C<FS_SYNC_FL>, C<FS_IMMUTABLE_FL>,
1264C<FS_APPEND_FL>, C<FS_NODUMP_FL>, C<FS_NOATIME_FL>, C<FS_DIRTY_FL>,
1265C<FS_COMPRBLK_FL>, C<FS_NOCOMP_FL>, C<FS_ENCRYPT_FL>, C<FS_BTREE_FL>,
1266C<FS_INDEX_FL>, C<FS_JOURNAL_DATA_FL>, C<FS_NOTAIL_FL>, C<FS_DIRSYNC_FL>, C<FS_TOPDIR_FL>,
1267C<FS_FL_USER_MODIFIABLE>.
1268
1269C<FS_XFLAG_REALTIME>, C<FS_XFLAG_PREALLOC>, C<FS_XFLAG_IMMUTABLE>, C<FS_XFLAG_APPEND>,
1270C<FS_XFLAG_SYNC>, C<FS_XFLAG_NOATIME>, C<FS_XFLAG_NODUMP>, C<FS_XFLAG_RTINHERIT>,
1271C<FS_XFLAG_PROJINHERIT>, C<FS_XFLAG_NOSYMLINKS>, C<FS_XFLAG_EXTSIZE>, C<FS_XFLAG_EXTSZINHERIT>,
1272C<FS_XFLAG_NODEFRAG>, C<FS_XFLAG_FILESTREAM>, C<FS_XFLAG_DAX>, C<FS_XFLAG_HASATTR>,
1095 1273
1096=item aio_sync $callback->($status) 1274=item aio_sync $callback->($status)
1097 1275
1098Asynchronously call sync and call the callback when finished. 1276Asynchronously call sync and call the callback when finished.
1099 1277
1189 1367
1190This is a rather advanced IO::AIO call, which works best on mmap(2)ed 1368This is a rather advanced IO::AIO call, which works best on mmap(2)ed
1191scalars. 1369scalars.
1192 1370
1193It touches (reads or writes) all memory pages in the specified 1371It touches (reads or writes) all memory pages in the specified
1194range inside the scalar. All caveats and parameters are the same 1372range inside the scalar. All caveats and parameters are the same
1195as for C<aio_msync>, above, except for flags, which must be either 1373as for C<aio_msync>, above, except for flags, which must be either
1196C<0> (which reads all pages and ensures they are instantiated) or 1374C<0> (which reads all pages and ensures they are instantiated) or
1197C<IO::AIO::MT_MODIFY>, which modifies the memory page s(by reading and 1375C<IO::AIO::MT_MODIFY>, which modifies the memory pages (by reading and
1198writing an octet from it, which dirties the page). 1376writing an octet from it, which dirties the page).
1199 1377
1200=item aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status) 1378=item aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status)
1201 1379
1202This is a rather advanced IO::AIO call, which works best on mmap(2)ed 1380This is a rather advanced IO::AIO call, which works best on mmap(2)ed
1233documented under L<MISCELLANEOUS FUNCTIONS>. 1411documented under L<MISCELLANEOUS FUNCTIONS>.
1234 1412
1235Example: asynchronously lock all current and future pages into memory. 1413Example: asynchronously lock all current and future pages into memory.
1236 1414
1237 aio_mlockall IO::AIO::MCL_FUTURE; 1415 aio_mlockall IO::AIO::MCL_FUTURE;
1416
1417=item aio_fiemap $fh, $start, $length, $flags, $count, $cb->(\@extents)
1418
1419Queries the extents of the given file (by calling the Linux C<FIEMAP>
1420ioctl, see L<http://cvs.schmorp.de/IO-AIO/doc/fiemap.txt> for details). If
1421the ioctl is not available on your OS, then this request will fail with
1422C<ENOSYS>.
1423
1424C<$start> is the starting offset to query extents for, C<$length> is the
1425size of the range to query - if it is C<undef>, then the whole file will
1426be queried.
1427
1428C<$flags> is a combination of flags (C<IO::AIO::FIEMAP_FLAG_SYNC> or
1429C<IO::AIO::FIEMAP_FLAG_XATTR> - C<IO::AIO::FIEMAP_FLAGS_COMPAT> is also
1430exported), and is normally C<0> or C<IO::AIO::FIEMAP_FLAG_SYNC> to query
1431the data portion.
1432
1433C<$count> is the maximum number of extent records to return. If it is
1434C<undef>, then IO::AIO queries all extents of the range. As a very special
1435case, if it is C<0>, then the callback receives the number of extents
1436instead of the extents themselves (which is unreliable, see below).
1437
1438If an error occurs, the callback receives no arguments. The special
1439C<errno> value C<IO::AIO::EBADR> is available to test for flag errors.
1440
1441Otherwise, the callback receives an array reference with extent
1442structures. Each extent structure is an array reference itself, with the
1443following members:
1444
1445 [$logical, $physical, $length, $flags]
1446
1447Flags is any combination of the following flag values (typically either C<0>
1448or C<IO::AIO::FIEMAP_EXTENT_LAST> (1)):
1449
1450C<IO::AIO::FIEMAP_EXTENT_LAST>, C<IO::AIO::FIEMAP_EXTENT_UNKNOWN>,
1451C<IO::AIO::FIEMAP_EXTENT_DELALLOC>, C<IO::AIO::FIEMAP_EXTENT_ENCODED>,
1452C<IO::AIO::FIEMAP_EXTENT_DATA_ENCRYPTED>, C<IO::AIO::FIEMAP_EXTENT_NOT_ALIGNED>,
1453C<IO::AIO::FIEMAP_EXTENT_DATA_INLINE>, C<IO::AIO::FIEMAP_EXTENT_DATA_TAIL>,
1454C<IO::AIO::FIEMAP_EXTENT_UNWRITTEN>, C<IO::AIO::FIEMAP_EXTENT_MERGED> or
1455C<IO::AIO::FIEMAP_EXTENT_SHARED>.
1456
1457At the time of this writing (Linux 3.2), this requets is unreliable unless
1458C<$count> is C<undef>, as the kernel has all sorts of bugs preventing
1459it to return all extents of a range for files with large number of
1460extents. The code works around all these issues if C<$count> is undef.
1238 1461
1239=item aio_group $callback->(...) 1462=item aio_group $callback->(...)
1240 1463
1241This is a very special aio request: Instead of doing something, it is a 1464This is a very special aio request: Instead of doing something, it is a
1242container for other aio requests, which is useful if you want to bundle 1465container for other aio requests, which is useful if you want to bundle
1326 aio_stat [$etcdir, "passwd"], sub { 1549 aio_stat [$etcdir, "passwd"], sub {
1327 # yay 1550 # yay
1328 }; 1551 };
1329 }; 1552 };
1330 1553
1331That C<aio_wd> is a request and not a normal function shows that creating 1554The fact that C<aio_wd> is a request and not a normal function shows that
1332an IO::AIO::WD object is itself a potentially blocking operation, which is 1555creating an IO::AIO::WD object is itself a potentially blocking operation,
1333why it is done asynchronously. 1556which is why it is done asynchronously.
1334 1557
1335To stat the directory obtained with C<aio_wd> above, one could write 1558To stat the directory obtained with C<aio_wd> above, one could write
1336either of the following three request calls: 1559either of the following three request calls:
1337 1560
1338 aio_lstat "/etc" , sub { ... # pathname as normal string 1561 aio_lstat "/etc" , sub { ... # pathname as normal string
1358will still point to the original directory. Most functions accepting a 1581will still point to the original directory. Most functions accepting a
1359pathname will use the directory fd on newer systems, and the string on 1582pathname will use the directory fd on newer systems, and the string on
1360older systems. Some functions (such as realpath) will always rely on the 1583older systems. Some functions (such as realpath) will always rely on the
1361string form of the pathname. 1584string form of the pathname.
1362 1585
1363So this fucntionality is mainly useful to get some protection against 1586So this functionality is mainly useful to get some protection against
1364C<chdir>, to easily get an absolute path out of a relative path for future 1587C<chdir>, to easily get an absolute path out of a relative path for future
1365reference, and to speed up doing many operations in the same directory 1588reference, and to speed up doing many operations in the same directory
1366(e.g. when stat'ing all files in a directory). 1589(e.g. when stat'ing all files in a directory).
1367 1590
1368The following functions implement this working directory abstraction: 1591The following functions implement this working directory abstraction:
1381passing C<undef> as working directory component of a pathname fails the 1604passing C<undef> as working directory component of a pathname fails the
1382request with C<ENOENT>, there is often no need for error checking in the 1605request with C<ENOENT>, there is often no need for error checking in the
1383C<aio_wd> callback, as future requests using the value will fail in the 1606C<aio_wd> callback, as future requests using the value will fail in the
1384expected way. 1607expected way.
1385 1608
1386If this call isn't available because your OS lacks it or it couldn't be
1387detected, it will be emulated by calling C<fsync> instead.
1388
1389=item IO::AIO::CWD 1609=item IO::AIO::CWD
1390 1610
1391This is a compiletime constant (object) that represents the process 1611This is a compiletime constant (object) that represents the process
1392current working directory. 1612current working directory.
1393 1613
1394Specifying this object as working directory object for a pathname is as 1614Specifying this object as working directory object for a pathname is as if
1395if the pathname would be specified directly, without a directory object, 1615the pathname would be specified directly, without a directory object. For
1396e.g., these calls are functionally identical: 1616example, these calls are functionally identical:
1397 1617
1398 aio_stat "somefile", sub { ... }; 1618 aio_stat "somefile", sub { ... };
1399 aio_stat [IO::AIO::CWD, "somefile"], sub { ... }; 1619 aio_stat [IO::AIO::CWD, "somefile"], sub { ... };
1400 1620
1401=back 1621=back
1402 1622
1623To recover the path associated with an IO::AIO::WD object, you can use
1624C<aio_realpath>:
1625
1626 aio_realpath $wd, sub {
1627 warn "path is $_[0]\n";
1628 };
1629
1630Currently, C<aio_statvfs> always, and C<aio_rename> and C<aio_rmdir>
1631sometimes, fall back to using an absolue path.
1403 1632
1404=head2 IO::AIO::REQ CLASS 1633=head2 IO::AIO::REQ CLASS
1405 1634
1406All non-aggregate C<aio_*> functions return an object of this class when 1635All non-aggregate C<aio_*> functions return an object of this class when
1407called in non-void context. 1636called in non-void context.
1585 1814
1586See C<poll_cb> for an example. 1815See C<poll_cb> for an example.
1587 1816
1588=item IO::AIO::poll_cb 1817=item IO::AIO::poll_cb
1589 1818
1590Process some outstanding events on the result pipe. You have to call 1819Process some requests that have reached the result phase (i.e. they have
1820been executed but the results are not yet reported). You have to call
1821this "regularly" to finish outstanding requests.
1822
1591this regularly. Returns C<0> if all events could be processed (or there 1823Returns C<0> if all events could be processed (or there were no
1592were no events to process), or C<-1> if it returned earlier for whatever 1824events to process), or C<-1> if it returned earlier for whatever
1593reason. Returns immediately when no events are outstanding. The amount of 1825reason. Returns immediately when no events are outstanding. The amount
1594events processed depends on the settings of C<IO::AIO::max_poll_req> and 1826of events processed depends on the settings of C<IO::AIO::max_poll_req>,
1595C<IO::AIO::max_poll_time>. 1827C<IO::AIO::max_poll_time> and C<IO::AIO::max_outstanding>.
1596 1828
1597If not all requests were processed for whatever reason, the filehandle 1829If not all requests were processed for whatever reason, the poll file
1598will still be ready when C<poll_cb> returns, so normally you don't have to 1830descriptor will still be ready when C<poll_cb> returns, so normally you
1599do anything special to have it called later. 1831don't have to do anything special to have it called later.
1600 1832
1601Apart from calling C<IO::AIO::poll_cb> when the event filehandle becomes 1833Apart from calling C<IO::AIO::poll_cb> when the event filehandle becomes
1602ready, it can be beneficial to call this function from loops which submit 1834ready, it can be beneficial to call this function from loops which submit
1603a lot of requests, to make sure the results get processed when they become 1835a lot of requests, to make sure the results get processed when they become
1604available and not just when the loop is finished and the event loop takes 1836available and not just when the loop is finished and the event loop takes
1613 poll => 'r', async => 1, 1845 poll => 'r', async => 1,
1614 cb => \&IO::AIO::poll_cb); 1846 cb => \&IO::AIO::poll_cb);
1615 1847
1616=item IO::AIO::poll_wait 1848=item IO::AIO::poll_wait
1617 1849
1618If there are any outstanding requests and none of them in the result 1850Wait until either at least one request is in the result phase or no
1619phase, wait till the result filehandle becomes ready for reading (simply 1851requests are outstanding anymore.
1620does a C<select> on the filehandle. This is useful if you want to 1852
1621synchronously wait for some requests to finish). 1853This is useful if you want to synchronously wait for some requests to
1854become ready, without actually handling them.
1622 1855
1623See C<nreqs> for an example. 1856See C<nreqs> for an example.
1624 1857
1625=item IO::AIO::poll 1858=item IO::AIO::poll
1626 1859
1747 1980
1748This is a very bad function to use in interactive programs because it 1981This is a very bad function to use in interactive programs because it
1749blocks, and a bad way to reduce concurrency because it is inexact: Better 1982blocks, and a bad way to reduce concurrency because it is inexact: Better
1750use an C<aio_group> together with a feed callback. 1983use an C<aio_group> together with a feed callback.
1751 1984
1752It's main use is in scripts without an event loop - when you want to stat 1985Its main use is in scripts without an event loop - when you want to stat
1753a lot of files, you can write somehting like this: 1986a lot of files, you can write somehting like this:
1754 1987
1755 IO::AIO::max_outstanding 32; 1988 IO::AIO::max_outstanding 32;
1756 1989
1757 for my $path (...) { 1990 for my $path (...) {
1797 2030
1798=back 2031=back
1799 2032
1800=head3 MISCELLANEOUS FUNCTIONS 2033=head3 MISCELLANEOUS FUNCTIONS
1801 2034
1802IO::AIO implements some functions that might be useful, but are not 2035IO::AIO implements some functions that are useful when you want to use
1803asynchronous. 2036some "Advanced I/O" function not available to in Perl, without going the
2037"Asynchronous I/O" route. Many of these have an asynchronous C<aio_*>
2038counterpart.
1804 2039
1805=over 4 2040=over 4
1806 2041
1807=item IO::AIO::sendfile $ofh, $ifh, $offset, $count 2042=item IO::AIO::sendfile $ofh, $ifh, $offset, $count
1808 2043
1827=item IO::AIO::madvise $scalar, $offset, $len, $advice 2062=item IO::AIO::madvise $scalar, $offset, $len, $advice
1828 2063
1829Simply calls the C<posix_madvise> function (see its 2064Simply calls the C<posix_madvise> function (see its
1830manpage for details). The following advice constants are 2065manpage for details). The following advice constants are
1831available: C<IO::AIO::MADV_NORMAL>, C<IO::AIO::MADV_SEQUENTIAL>, 2066available: C<IO::AIO::MADV_NORMAL>, C<IO::AIO::MADV_SEQUENTIAL>,
1832C<IO::AIO::MADV_RANDOM>, C<IO::AIO::MADV_WILLNEED>, C<IO::AIO::MADV_DONTNEED>. 2067C<IO::AIO::MADV_RANDOM>, C<IO::AIO::MADV_WILLNEED>, C<IO::AIO::MADV_DONTNEED>,
2068C<IO::AIO::MADV_FREE>.
1833 2069
1834On systems that do not implement C<posix_madvise>, this function returns 2070On systems that do not implement C<posix_madvise>, this function returns
1835ENOSYS, otherwise the return value of C<posix_madvise>. 2071ENOSYS, otherwise the return value of C<posix_madvise>.
1836 2072
1837=item IO::AIO::mprotect $scalar, $offset, $len, $protect 2073=item IO::AIO::mprotect $scalar, $offset, $len, $protect
1845ENOSYS, otherwise the return value of C<mprotect>. 2081ENOSYS, otherwise the return value of C<mprotect>.
1846 2082
1847=item IO::AIO::mmap $scalar, $length, $prot, $flags, $fh[, $offset] 2083=item IO::AIO::mmap $scalar, $length, $prot, $flags, $fh[, $offset]
1848 2084
1849Memory-maps a file (or anonymous memory range) and attaches it to the 2085Memory-maps a file (or anonymous memory range) and attaches it to the
1850given C<$scalar>, which will act like a string scalar. 2086given C<$scalar>, which will act like a string scalar. Returns true on
2087success, and false otherwise.
1851 2088
1852The only operations allowed on the scalar are C<substr>/C<vec> that don't 2089The only operations allowed on the scalar are C<substr>/C<vec> that don't
1853change the string length, and most read-only operations such as copying it 2090change the string length, and most read-only operations such as copying it
1854or searching it with regexes and so on. 2091or searching it with regexes and so on.
1855 2092
1866filesize. 2103filesize.
1867 2104
1868C<$prot> is a combination of C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_EXEC>, 2105C<$prot> is a combination of C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_EXEC>,
1869C<IO::AIO::PROT_READ> and/or C<IO::AIO::PROT_WRITE>, 2106C<IO::AIO::PROT_READ> and/or C<IO::AIO::PROT_WRITE>,
1870 2107
1871C<$flags> can be a combination of C<IO::AIO::MAP_SHARED> or 2108C<$flags> can be a combination of
1872C<IO::AIO::MAP_PRIVATE>, or a number of system-specific flags (when 2109C<IO::AIO::MAP_SHARED> or
1873not available, the are defined as 0): C<IO::AIO::MAP_ANONYMOUS> 2110C<IO::AIO::MAP_PRIVATE>,
2111or a number of system-specific flags (when not available, the are C<0>):
1874(which is set to C<MAP_ANON> if your system only provides this 2112C<IO::AIO::MAP_ANONYMOUS> (which is set to C<MAP_ANON> if your system only provides this constant),
1875constant), C<IO::AIO::MAP_HUGETLB>, C<IO::AIO::MAP_LOCKED>, 2113C<IO::AIO::MAP_LOCKED>,
1876C<IO::AIO::MAP_NORESERVE>, C<IO::AIO::MAP_POPULATE> or 2114C<IO::AIO::MAP_NORESERVE>,
2115C<IO::AIO::MAP_POPULATE>,
1877C<IO::AIO::MAP_NONBLOCK> 2116C<IO::AIO::MAP_NONBLOCK>,
2117C<IO::AIO::MAP_FIXED>,
2118C<IO::AIO::MAP_GROWSDOWN>,
2119C<IO::AIO::MAP_32BIT>,
2120C<IO::AIO::MAP_HUGETLB> or
2121C<IO::AIO::MAP_STACK>.
1878 2122
1879If C<$fh> is C<undef>, then a file descriptor of C<-1> is passed. 2123If C<$fh> is C<undef>, then a file descriptor of C<-1> is passed.
1880 2124
1881C<$offset> is the offset from the start of the file - it generally must be 2125C<$offset> is the offset from the start of the file - it generally must be
1882a multiple of C<IO::AIO::PAGESIZE> and defaults to C<0>. 2126a multiple of C<IO::AIO::PAGESIZE> and defaults to C<0>.
1907 2151
1908Calls the C<munlockall> function. 2152Calls the C<munlockall> function.
1909 2153
1910On systems that do not implement C<munlockall>, this function returns 2154On systems that do not implement C<munlockall>, this function returns
1911ENOSYS, otherwise the return value of C<munlockall>. 2155ENOSYS, otherwise the return value of C<munlockall>.
2156
2157=item IO::AIO::splice $r_fh, $r_off, $w_fh, $w_off, $length, $flags
2158
2159Calls the GNU/Linux C<splice(2)> syscall, if available. If C<$r_off> or
2160C<$w_off> are C<undef>, then C<NULL> is passed for these, otherwise they
2161should be the file offset.
2162
2163C<$r_fh> and C<$w_fh> should not refer to the same file, as splice might
2164silently corrupt the data in this case.
2165
2166The following symbol flag values are available: C<IO::AIO::SPLICE_F_MOVE>,
2167C<IO::AIO::SPLICE_F_NONBLOCK>, C<IO::AIO::SPLICE_F_MORE> and
2168C<IO::AIO::SPLICE_F_GIFT>.
2169
2170See the C<splice(2)> manpage for details.
2171
2172=item IO::AIO::tee $r_fh, $w_fh, $length, $flags
2173
2174Calls the GNU/Linux C<tee(2)> syscall, see its manpage and the
2175description for C<IO::AIO::splice> above for details.
2176
2177=item $actual_size = IO::AIO::pipesize $r_fh[, $new_size]
2178
2179Attempts to query or change the pipe buffer size. Obviously works only
2180on pipes, and currently works only on GNU/Linux systems, and fails with
2181C<-1>/C<ENOSYS> everywhere else. If anybody knows how to influence pipe buffer
2182size on other systems, drop me a note.
2183
2184=item ($rfh, $wfh) = IO::AIO::pipe2 [$flags]
2185
2186This is a direct interface to the Linux L<pipe2(2)> system call. If
2187C<$flags> is missing or C<0>, then this should be the same as a call to
2188perl's built-in C<pipe> function and create a new pipe, and works on
2189systems that lack the pipe2 syscall. On win32, this case invokes C<_pipe
2190(..., 4096, O_BINARY)>.
2191
2192If C<$flags> is non-zero, it tries to invoke the pipe2 system call with
2193the given flags (Linux 2.6.27, glibc 2.9).
2194
2195On success, the read and write file handles are returned.
2196
2197On error, nothing will be returned. If the pipe2 syscall is missing and
2198C<$flags> is non-zero, fails with C<ENOSYS>.
2199
2200Please refer to L<pipe2(2)> for more info on the C<$flags>, but at the
2201time of this writing, C<IO::AIO::O_CLOEXEC>, C<IO::AIO::O_NONBLOCK> and
2202C<IO::AIO::O_DIRECT> (Linux 3.4, for packet-based pipes) were supported.
1912 2203
1913=back 2204=back
1914 2205
1915=cut 2206=cut
1916 2207

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