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Comparing IO-AIO/AIO.pm (file contents):
Revision 1.227 by root, Tue May 29 03:58:02 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 = '4.15'; 172 our $VERSION = 4.34;
174 173
175 our @AIO_REQ = qw(aio_sendfile aio_seek 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 aio_fiemap 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)
221 aio_statvfs $fh_or_path, $callback->($statvfs) 220 aio_statvfs $fh_or_path, $callback->($statvfs)
222 aio_utime $fh_or_path, $atime, $mtime, $callback->($status) 221 aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
223 aio_chown $fh_or_path, $uid, $gid, $callback->($status) 222 aio_chown $fh_or_path, $uid, $gid, $callback->($status)
224 aio_chmod $fh_or_path, $mode, $callback->($status) 223 aio_chmod $fh_or_path, $mode, $callback->($status)
225 aio_truncate $fh_or_path, $offset, $callback->($status) 224 aio_truncate $fh_or_path, $offset, $callback->($status)
225 aio_allocate $fh, $mode, $offset, $len, $callback->($status)
226 aio_fiemap $fh, $start, $length, $flags, $count, $cb->(\@extents)
226 aio_unlink $pathname, $callback->($status) 227 aio_unlink $pathname, $callback->($status)
227 aio_mknod $pathname, $mode, $dev, $callback->($status) 228 aio_mknod $pathname, $mode, $dev, $callback->($status)
228 aio_link $srcpath, $dstpath, $callback->($status) 229 aio_link $srcpath, $dstpath, $callback->($status)
229 aio_symlink $srcpath, $dstpath, $callback->($status) 230 aio_symlink $srcpath, $dstpath, $callback->($status)
230 aio_readlink $pathname, $callback->($link) 231 aio_readlink $pathname, $callback->($link)
231 aio_realpath $pathname, $callback->($link) 232 aio_realpath $pathname, $callback->($path)
232 aio_rename $srcpath, $dstpath, $callback->($status) 233 aio_rename $srcpath, $dstpath, $callback->($status)
233 aio_mkdir $pathname, $mode, $callback->($status) 234 aio_mkdir $pathname, $mode, $callback->($status)
234 aio_rmdir $pathname, $callback->($status) 235 aio_rmdir $pathname, $callback->($status)
235 aio_readdir $pathname, $callback->($entries) 236 aio_readdir $pathname, $callback->($entries)
236 aio_readdirx $pathname, $flags, $callback->($entries, $flags) 237 aio_readdirx $pathname, $flags, $callback->($entries, $flags)
239 aio_scandir $pathname, $maxreq, $callback->($dirs, $nondirs) 240 aio_scandir $pathname, $maxreq, $callback->($dirs, $nondirs)
240 aio_load $pathname, $data, $callback->($status) 241 aio_load $pathname, $data, $callback->($status)
241 aio_copy $srcpath, $dstpath, $callback->($status) 242 aio_copy $srcpath, $dstpath, $callback->($status)
242 aio_move $srcpath, $dstpath, $callback->($status) 243 aio_move $srcpath, $dstpath, $callback->($status)
243 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)
244 aio_sync $callback->($status) 247 aio_sync $callback->($status)
245 aio_syncfs $fh, $callback->($status) 248 aio_syncfs $fh, $callback->($status)
246 aio_fsync $fh, $callback->($status) 249 aio_fsync $fh, $callback->($status)
247 aio_fdatasync $fh, $callback->($status) 250 aio_fdatasync $fh, $callback->($status)
248 aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status) 251 aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status)
360 363
361 364
362=item aio_open $pathname, $flags, $mode, $callback->($fh) 365=item aio_open $pathname, $flags, $mode, $callback->($fh)
363 366
364Asynchronously 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
365created filehandle for the file. 368created filehandle for the file (or C<undef> in case of an error).
366 369
367The 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,
368for an explanation. 371for an explanation.
369 372
370The 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
393following POSIX and non-POSIX constants are available (missing ones on 396following POSIX and non-POSIX constants are available (missing ones on
394your system are, as usual, C<0>): 397your system are, as usual, C<0>):
395 398
396C<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>,
397C<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>,
398C<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>.
399 402
400 403
401=item aio_close $fh, $callback->($status) 404=item aio_close $fh, $callback->($status)
402 405
403Asynchronously close a file and call the callback with the result 406Asynchronously close a file and call the callback with the result
507As native sendfile syscalls (as practically any non-POSIX interface hacked 510As native sendfile syscalls (as practically any non-POSIX interface hacked
508together 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
509on many systems, this implementation tries to work around some known bugs 512on many systems, this implementation tries to work around some known bugs
510in Linux and FreeBSD kernels (probably others, too), but that might fail, 513in Linux and FreeBSD kernels (probably others, too), but that might fail,
511so 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> -
512fewre bytes than expected might have been transferred. 515fewer bytes than expected might have been transferred.
513 516
514 517
515=item aio_readahead $fh,$offset,$length, $callback->($retval) 518=item aio_readahead $fh,$offset,$length, $callback->($retval)
516 519
517C<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
521whole 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
522and 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
523(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
524file. The current file offset of the file is left unchanged. 527file. The current file offset of the file is left unchanged.
525 528
526If 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
527emulated by simply reading the data, which would have a similar effect. 530be emulated by simply reading the data, which would have a similar effect.
528 531
529 532
530=item aio_stat $fh_or_path, $callback->($status) 533=item aio_stat $fh_or_path, $callback->($status)
531 534
532=item aio_lstat $fh, $callback->($status) 535=item aio_lstat $fh, $callback->($status)
601 namemax => 255, 604 namemax => 255,
602 frsize => 1024, 605 frsize => 1024,
603 fsid => 1810 606 fsid => 1810
604 } 607 }
605 608
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
606 693
607=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status) 694=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
608 695
609Works 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
610and $mtime being undef). Fractional times are supported if the underlying 697and $mtime being undef). Fractional times are supported if the underlying
638=item aio_truncate $fh_or_path, $offset, $callback->($status) 725=item aio_truncate $fh_or_path, $offset, $callback->($status)
639 726
640Works like truncate(2) or ftruncate(2). 727Works like truncate(2) or ftruncate(2).
641 728
642 729
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
643=item aio_chmod $fh_or_path, $mode, $callback->($status) 750=item aio_chmod $fh_or_path, $mode, $callback->($status)
644 751
645Works like perl's C<chmod> function. 752Works like perl's C<chmod> function.
646 753
647 754
684 791
685 792
686=item aio_realpath $pathname, $callback->($path) 793=item aio_realpath $pathname, $callback->($path)
687 794
688Asynchronously make the path absolute and resolve any symlinks in 795Asynchronously make the path absolute and resolve any symlinks in
689C<$path>. The resulting path only consists of directories (Same as 796C<$path>. The resulting path only consists of directories (same as
690L<Cwd::realpath>). 797L<Cwd::realpath>).
691 798
692This 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
693directory by passing it a path of F<.> (a single dot). 800directory by passing it a path of F<.> (a single dot).
694 801
695 802
696=item aio_rename $srcpath, $dstpath, $callback->($status) 803=item aio_rename $srcpath, $dstpath, $callback->($status)
697 804
698Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as 805Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as
699rename(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>.
700 811
701 812
702=item aio_mkdir $pathname, $mode, $callback->($status) 813=item aio_mkdir $pathname, $mode, $callback->($status)
703 814
704Asynchronously mkdir (create) a directory and call the callback with 815Asynchronously mkdir (create) a directory and call the callback with
708 819
709=item aio_rmdir $pathname, $callback->($status) 820=item aio_rmdir $pathname, $callback->($status)
710 821
711Asynchronously rmdir (delete) a directory and call the callback with the 822Asynchronously rmdir (delete) a directory and call the callback with the
712result 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>.
713 828
714 829
715=item aio_readdir $pathname, $callback->($entries) 830=item aio_readdir $pathname, $callback->($entries)
716 831
717Unlike 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
1082} 1197}
1083 1198
1084=item aio_rmtree $pathname, $callback->($status) 1199=item aio_rmtree $pathname, $callback->($status)
1085 1200
1086Delete a directory tree starting (and including) C<$path>, return the 1201Delete a directory tree starting (and including) C<$path>, return the
1087status 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
1088uses C<aio_scandir> to recurse into and rmdir directories, and unlink 1203uses C<aio_scandir> to recurse into and rmdir directories, and unlink
1089everything else. 1204everything else.
1090 1205
1091=cut 1206=cut
1092 1207
1113 add $grp $dirgrp; 1228 add $grp $dirgrp;
1114 }; 1229 };
1115 1230
1116 $grp 1231 $grp
1117} 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>,
1118 1273
1119=item aio_sync $callback->($status) 1274=item aio_sync $callback->($status)
1120 1275
1121Asynchronously call sync and call the callback when finished. 1276Asynchronously call sync and call the callback when finished.
1122 1277
1212 1367
1213This 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
1214scalars. 1369scalars.
1215 1370
1216It touches (reads or writes) all memory pages in the specified 1371It touches (reads or writes) all memory pages in the specified
1217range inside the scalar. All caveats and parameters are the same 1372range inside the scalar. All caveats and parameters are the same
1218as 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
1219C<0> (which reads all pages and ensures they are instantiated) or 1374C<0> (which reads all pages and ensures they are instantiated) or
1220C<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
1221writing an octet from it, which dirties the page). 1376writing an octet from it, which dirties the page).
1222 1377
1223=item aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status) 1378=item aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status)
1224 1379
1225This 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
1259 1414
1260 aio_mlockall IO::AIO::MCL_FUTURE; 1415 aio_mlockall IO::AIO::MCL_FUTURE;
1261 1416
1262=item aio_fiemap $fh, $start, $length, $flags, $count, $cb->(\@extents) 1417=item aio_fiemap $fh, $start, $length, $flags, $count, $cb->(\@extents)
1263 1418
1264Queries the extents of the given file (by calling the Linux FIEMAP ioctl, 1419Queries the extents of the given file (by calling the Linux C<FIEMAP>
1265see L<http://cvs.schmorp.de/IO-AIO/doc/fiemap.txt> for details). If the 1420ioctl, see L<http://cvs.schmorp.de/IO-AIO/doc/fiemap.txt> for details). If
1266C<ioctl> is not available on your OS, then this rquiest will fail with 1421the ioctl is not available on your OS, then this request will fail with
1267C<ENOSYS>. 1422C<ENOSYS>.
1268 1423
1269C<$start> is the starting offset to query extents for, C<$length> is the 1424C<$start> is the starting offset to query extents for, C<$length> is the
1270size of the range to query - if it is C<undef>, then the whole file will 1425size of the range to query - if it is C<undef>, then the whole file will
1271be queried. 1426be queried.
1274C<IO::AIO::FIEMAP_FLAG_XATTR> - C<IO::AIO::FIEMAP_FLAGS_COMPAT> is also 1429C<IO::AIO::FIEMAP_FLAG_XATTR> - C<IO::AIO::FIEMAP_FLAGS_COMPAT> is also
1275exported), and is normally C<0> or C<IO::AIO::FIEMAP_FLAG_SYNC> to query 1430exported), and is normally C<0> or C<IO::AIO::FIEMAP_FLAG_SYNC> to query
1276the data portion. 1431the data portion.
1277 1432
1278C<$count> is the maximum number of extent records to return. If it is 1433C<$count> is the maximum number of extent records to return. If it is
1279C<undef>, then IO::AIO queries all extents of the file. As a very special 1434C<undef>, then IO::AIO queries all extents of the range. As a very special
1280case, if it is C<0>, then the callback receives the number of extents 1435case, if it is C<0>, then the callback receives the number of extents
1281instead of the extents themselves. 1436instead of the extents themselves (which is unreliable, see below).
1282 1437
1283If an error occurs, the callback receives no arguments. The special 1438If an error occurs, the callback receives no arguments. The special
1284C<errno> value C<IO::AIO::EBADR> is available to test for flag errors. 1439C<errno> value C<IO::AIO::EBADR> is available to test for flag errors.
1285 1440
1286Otherwise, the callback receives an array reference with extent 1441Otherwise, the callback receives an array reference with extent
1288following members: 1443following members:
1289 1444
1290 [$logical, $physical, $length, $flags] 1445 [$logical, $physical, $length, $flags]
1291 1446
1292Flags is any combination of the following flag values (typically either C<0> 1447Flags is any combination of the following flag values (typically either C<0>
1293or C<IO::AIO::FIEMAP_EXTENT_LAST>): 1448or C<IO::AIO::FIEMAP_EXTENT_LAST> (1)):
1294 1449
1295C<IO::AIO::FIEMAP_EXTENT_LAST>, C<IO::AIO::FIEMAP_EXTENT_UNKNOWN>, 1450C<IO::AIO::FIEMAP_EXTENT_LAST>, C<IO::AIO::FIEMAP_EXTENT_UNKNOWN>,
1296C<IO::AIO::FIEMAP_EXTENT_DELALLOC>, C<IO::AIO::FIEMAP_EXTENT_ENCODED>, 1451C<IO::AIO::FIEMAP_EXTENT_DELALLOC>, C<IO::AIO::FIEMAP_EXTENT_ENCODED>,
1297C<IO::AIO::FIEMAP_EXTENT_DATA_ENCRYPTED>, C<IO::AIO::FIEMAP_EXTENT_NOT_ALIGNED>, 1452C<IO::AIO::FIEMAP_EXTENT_DATA_ENCRYPTED>, C<IO::AIO::FIEMAP_EXTENT_NOT_ALIGNED>,
1298C<IO::AIO::FIEMAP_EXTENT_DATA_INLINE>, C<IO::AIO::FIEMAP_EXTENT_DATA_TAIL>, 1453C<IO::AIO::FIEMAP_EXTENT_DATA_INLINE>, C<IO::AIO::FIEMAP_EXTENT_DATA_TAIL>,
1299C<IO::AIO::FIEMAP_EXTENT_UNWRITTEN>, C<IO::AIO::FIEMAP_EXTENT_MERGED> or 1454C<IO::AIO::FIEMAP_EXTENT_UNWRITTEN>, C<IO::AIO::FIEMAP_EXTENT_MERGED> or
1300C<IO::AIO::FIEMAP_EXTENT_SHARED>. 1455C<IO::AIO::FIEMAP_EXTENT_SHARED>.
1301 1456
1457At the time of this writing (Linux 3.2), this requets is unreliable unless
1458C<$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.
1461
1302=item aio_group $callback->(...) 1462=item aio_group $callback->(...)
1303 1463
1304This is a very special aio request: Instead of doing something, it is a 1464This is a very special aio request: Instead of doing something, it is a
1305container for other aio requests, which is useful if you want to bundle 1465container for other aio requests, which is useful if you want to bundle
1306many requests into a single, composite, request with a definite callback 1466many requests into a single, composite, request with a definite callback
1389 aio_stat [$etcdir, "passwd"], sub { 1549 aio_stat [$etcdir, "passwd"], sub {
1390 # yay 1550 # yay
1391 }; 1551 };
1392 }; 1552 };
1393 1553
1394That 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
1395an IO::AIO::WD object is itself a potentially blocking operation, which is 1555creating an IO::AIO::WD object is itself a potentially blocking operation,
1396why it is done asynchronously. 1556which is why it is done asynchronously.
1397 1557
1398To 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
1399either of the following three request calls: 1559either of the following three request calls:
1400 1560
1401 aio_lstat "/etc" , sub { ... # pathname as normal string 1561 aio_lstat "/etc" , sub { ... # pathname as normal string
1421will still point to the original directory. Most functions accepting a 1581will still point to the original directory. Most functions accepting a
1422pathname 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
1423older systems. Some functions (such as realpath) will always rely on the 1583older systems. Some functions (such as realpath) will always rely on the
1424string form of the pathname. 1584string form of the pathname.
1425 1585
1426So this fucntionality is mainly useful to get some protection against 1586So this functionality is mainly useful to get some protection against
1427C<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
1428reference, and to speed up doing many operations in the same directory 1588reference, and to speed up doing many operations in the same directory
1429(e.g. when stat'ing all files in a directory). 1589(e.g. when stat'ing all files in a directory).
1430 1590
1431The following functions implement this working directory abstraction: 1591The following functions implement this working directory abstraction:
1444passing C<undef> as working directory component of a pathname fails the 1604passing C<undef> as working directory component of a pathname fails the
1445request 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
1446C<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
1447expected way. 1607expected way.
1448 1608
1449If this call isn't available because your OS lacks it or it couldn't be
1450detected, it will be emulated by calling C<fsync> instead.
1451
1452=item IO::AIO::CWD 1609=item IO::AIO::CWD
1453 1610
1454This is a compiletime constant (object) that represents the process 1611This is a compiletime constant (object) that represents the process
1455current working directory. 1612current working directory.
1456 1613
1457Specifying this object as working directory object for a pathname is as 1614Specifying this object as working directory object for a pathname is as if
1458if the pathname would be specified directly, without a directory object, 1615the pathname would be specified directly, without a directory object. For
1459e.g., these calls are functionally identical: 1616example, these calls are functionally identical:
1460 1617
1461 aio_stat "somefile", sub { ... }; 1618 aio_stat "somefile", sub { ... };
1462 aio_stat [IO::AIO::CWD, "somefile"], sub { ... }; 1619 aio_stat [IO::AIO::CWD, "somefile"], sub { ... };
1463 1620
1464=back 1621=back
1465 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.
1466 1632
1467=head2 IO::AIO::REQ CLASS 1633=head2 IO::AIO::REQ CLASS
1468 1634
1469All 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
1470called in non-void context. 1636called in non-void context.
1648 1814
1649See C<poll_cb> for an example. 1815See C<poll_cb> for an example.
1650 1816
1651=item IO::AIO::poll_cb 1817=item IO::AIO::poll_cb
1652 1818
1653Process 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
1654this 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
1655were 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
1656reason. Returns immediately when no events are outstanding. The amount of 1825reason. Returns immediately when no events are outstanding. The amount
1657events 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>,
1658C<IO::AIO::max_poll_time>. 1827C<IO::AIO::max_poll_time> and C<IO::AIO::max_outstanding>.
1659 1828
1660If not all requests were processed for whatever reason, the filehandle 1829If not all requests were processed for whatever reason, the poll file
1661will 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
1662do anything special to have it called later. 1831don't have to do anything special to have it called later.
1663 1832
1664Apart 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
1665ready, 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
1666a 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
1667available 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
1676 poll => 'r', async => 1, 1845 poll => 'r', async => 1,
1677 cb => \&IO::AIO::poll_cb); 1846 cb => \&IO::AIO::poll_cb);
1678 1847
1679=item IO::AIO::poll_wait 1848=item IO::AIO::poll_wait
1680 1849
1681If 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
1682phase, wait till the result filehandle becomes ready for reading (simply 1851requests are outstanding anymore.
1683does a C<select> on the filehandle. This is useful if you want to 1852
1684synchronously 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.
1685 1855
1686See C<nreqs> for an example. 1856See C<nreqs> for an example.
1687 1857
1688=item IO::AIO::poll 1858=item IO::AIO::poll
1689 1859
1810 1980
1811This 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
1812blocks, 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
1813use an C<aio_group> together with a feed callback. 1983use an C<aio_group> together with a feed callback.
1814 1984
1815It'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
1816a lot of files, you can write somehting like this: 1986a lot of files, you can write somehting like this:
1817 1987
1818 IO::AIO::max_outstanding 32; 1988 IO::AIO::max_outstanding 32;
1819 1989
1820 for my $path (...) { 1990 for my $path (...) {
1860 2030
1861=back 2031=back
1862 2032
1863=head3 MISCELLANEOUS FUNCTIONS 2033=head3 MISCELLANEOUS FUNCTIONS
1864 2034
1865IO::AIO implements some functions that might be useful, but are not 2035IO::AIO implements some functions that are useful when you want to use
1866asynchronous. 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.
1867 2039
1868=over 4 2040=over 4
1869 2041
1870=item IO::AIO::sendfile $ofh, $ifh, $offset, $count 2042=item IO::AIO::sendfile $ofh, $ifh, $offset, $count
1871 2043
1890=item IO::AIO::madvise $scalar, $offset, $len, $advice 2062=item IO::AIO::madvise $scalar, $offset, $len, $advice
1891 2063
1892Simply calls the C<posix_madvise> function (see its 2064Simply calls the C<posix_madvise> function (see its
1893manpage for details). The following advice constants are 2065manpage for details). The following advice constants are
1894available: C<IO::AIO::MADV_NORMAL>, C<IO::AIO::MADV_SEQUENTIAL>, 2066available: C<IO::AIO::MADV_NORMAL>, C<IO::AIO::MADV_SEQUENTIAL>,
1895C<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>.
1896 2069
1897On systems that do not implement C<posix_madvise>, this function returns 2070On systems that do not implement C<posix_madvise>, this function returns
1898ENOSYS, otherwise the return value of C<posix_madvise>. 2071ENOSYS, otherwise the return value of C<posix_madvise>.
1899 2072
1900=item IO::AIO::mprotect $scalar, $offset, $len, $protect 2073=item IO::AIO::mprotect $scalar, $offset, $len, $protect
1908ENOSYS, otherwise the return value of C<mprotect>. 2081ENOSYS, otherwise the return value of C<mprotect>.
1909 2082
1910=item IO::AIO::mmap $scalar, $length, $prot, $flags, $fh[, $offset] 2083=item IO::AIO::mmap $scalar, $length, $prot, $flags, $fh[, $offset]
1911 2084
1912Memory-maps a file (or anonymous memory range) and attaches it to the 2085Memory-maps a file (or anonymous memory range) and attaches it to the
1913given C<$scalar>, which will act like a string scalar. 2086given C<$scalar>, which will act like a string scalar. Returns true on
2087success, and false otherwise.
1914 2088
1915The only operations allowed on the scalar are C<substr>/C<vec> that don't 2089The only operations allowed on the scalar are C<substr>/C<vec> that don't
1916change the string length, and most read-only operations such as copying it 2090change the string length, and most read-only operations such as copying it
1917or searching it with regexes and so on. 2091or searching it with regexes and so on.
1918 2092
1929filesize. 2103filesize.
1930 2104
1931C<$prot> is a combination of C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_EXEC>, 2105C<$prot> is a combination of C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_EXEC>,
1932C<IO::AIO::PROT_READ> and/or C<IO::AIO::PROT_WRITE>, 2106C<IO::AIO::PROT_READ> and/or C<IO::AIO::PROT_WRITE>,
1933 2107
1934C<$flags> can be a combination of C<IO::AIO::MAP_SHARED> or 2108C<$flags> can be a combination of
1935C<IO::AIO::MAP_PRIVATE>, or a number of system-specific flags (when 2109C<IO::AIO::MAP_SHARED> or
1936not available, the are defined as 0): C<IO::AIO::MAP_ANONYMOUS> 2110C<IO::AIO::MAP_PRIVATE>,
2111or a number of system-specific flags (when not available, the are C<0>):
1937(which is set to C<MAP_ANON> if your system only provides this 2112C<IO::AIO::MAP_ANONYMOUS> (which is set to C<MAP_ANON> if your system only provides this constant),
1938constant), C<IO::AIO::MAP_HUGETLB>, C<IO::AIO::MAP_LOCKED>, 2113C<IO::AIO::MAP_LOCKED>,
1939C<IO::AIO::MAP_NORESERVE>, C<IO::AIO::MAP_POPULATE> or 2114C<IO::AIO::MAP_NORESERVE>,
2115C<IO::AIO::MAP_POPULATE>,
1940C<IO::AIO::MAP_NONBLOCK> 2116C<IO::AIO::MAP_NONBLOCK>,
2117C<IO::AIO::MAP_FIXED>,
2118C<IO::AIO::MAP_GROWSDOWN>,
2119C<IO::AIO::MAP_32BIT>,
2120C<IO::AIO::MAP_HUGETLB> or
2121C<IO::AIO::MAP_STACK>.
1941 2122
1942If C<$fh> is C<undef>, then a file descriptor of C<-1> is passed. 2123If C<$fh> is C<undef>, then a file descriptor of C<-1> is passed.
1943 2124
1944C<$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
1945a multiple of C<IO::AIO::PAGESIZE> and defaults to C<0>. 2126a multiple of C<IO::AIO::PAGESIZE> and defaults to C<0>.
1988 2169
1989See the C<splice(2)> manpage for details. 2170See the C<splice(2)> manpage for details.
1990 2171
1991=item IO::AIO::tee $r_fh, $w_fh, $length, $flags 2172=item IO::AIO::tee $r_fh, $w_fh, $length, $flags
1992 2173
1993Calls the GNU/Linux C<tee(2)> syscall, see it's manpage and the 2174Calls the GNU/Linux C<tee(2)> syscall, see its manpage and the
1994description for C<IO::AIO::splice> above for details. 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.
1995 2203
1996=back 2204=back
1997 2205
1998=cut 2206=cut
1999 2207

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