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Revision 1.225 by root, Tue Apr 10 05:01:33 2012 UTC vs.
Revision 1.260 by root, Sun May 1 17:19:39 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)
272 IO::AIO::nready 275 IO::AIO::nready
273 IO::AIO::npending 276 IO::AIO::npending
274 277
275 IO::AIO::sendfile $ofh, $ifh, $offset, $count 278 IO::AIO::sendfile $ofh, $ifh, $offset, $count
276 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
277 IO::AIO::madvise $scalar, $offset, $length, $advice 282 IO::AIO::madvise $scalar, $offset, $length, $advice
278 IO::AIO::mprotect $scalar, $offset, $length, $protect 283 IO::AIO::mprotect $scalar, $offset, $length, $protect
279 IO::AIO::munlock $scalar, $offset = 0, $length = undef 284 IO::AIO::munlock $scalar, $offset = 0, $length = undef
280 IO::AIO::munlockall 285 IO::AIO::munlockall
281 286
358 363
359 364
360=item aio_open $pathname, $flags, $mode, $callback->($fh) 365=item aio_open $pathname, $flags, $mode, $callback->($fh)
361 366
362Asynchronously 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
363created filehandle for the file. 368created filehandle for the file (or C<undef> in case of an error).
364 369
365The 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,
366for an explanation. 371for an explanation.
367 372
368The 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
391following POSIX and non-POSIX constants are available (missing ones on 396following POSIX and non-POSIX constants are available (missing ones on
392your system are, as usual, C<0>): 397your system are, as usual, C<0>):
393 398
394C<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>,
395C<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>,
396C<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>.
397 402
398 403
399=item aio_close $fh, $callback->($status) 404=item aio_close $fh, $callback->($status)
400 405
401Asynchronously close a file and call the callback with the result 406Asynchronously close a file and call the callback with the result
599 namemax => 255, 604 namemax => 255,
600 frsize => 1024, 605 frsize => 1024,
601 fsid => 1810 606 fsid => 1810
602 } 607 }
603 608
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
604 693
605=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status) 694=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
606 695
607Works 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
608and $mtime being undef). Fractional times are supported if the underlying 697and $mtime being undef). Fractional times are supported if the underlying
636=item aio_truncate $fh_or_path, $offset, $callback->($status) 725=item aio_truncate $fh_or_path, $offset, $callback->($status)
637 726
638Works like truncate(2) or ftruncate(2). 727Works like truncate(2) or ftruncate(2).
639 728
640 729
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
641=item aio_chmod $fh_or_path, $mode, $callback->($status) 750=item aio_chmod $fh_or_path, $mode, $callback->($status)
642 751
643Works like perl's C<chmod> function. 752Works like perl's C<chmod> function.
644 753
645 754
682 791
683 792
684=item aio_realpath $pathname, $callback->($path) 793=item aio_realpath $pathname, $callback->($path)
685 794
686Asynchronously make the path absolute and resolve any symlinks in 795Asynchronously make the path absolute and resolve any symlinks in
687C<$path>. The resulting path only consists of directories (Same as 796C<$path>. The resulting path only consists of directories (same as
688L<Cwd::realpath>). 797L<Cwd::realpath>).
689 798
690This 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
691directory by passing it a path of F<.> (a single dot). 800directory by passing it a path of F<.> (a single dot).
692 801
693 802
694=item aio_rename $srcpath, $dstpath, $callback->($status) 803=item aio_rename $srcpath, $dstpath, $callback->($status)
695 804
696Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as 805Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as
697rename(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>.
698 811
699 812
700=item aio_mkdir $pathname, $mode, $callback->($status) 813=item aio_mkdir $pathname, $mode, $callback->($status)
701 814
702Asynchronously mkdir (create) a directory and call the callback with 815Asynchronously mkdir (create) a directory and call the callback with
706 819
707=item aio_rmdir $pathname, $callback->($status) 820=item aio_rmdir $pathname, $callback->($status)
708 821
709Asynchronously rmdir (delete) a directory and call the callback with the 822Asynchronously rmdir (delete) a directory and call the callback with the
710result 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>.
711 828
712 829
713=item aio_readdir $pathname, $callback->($entries) 830=item aio_readdir $pathname, $callback->($entries)
714 831
715Unlike 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
1080} 1197}
1081 1198
1082=item aio_rmtree $pathname, $callback->($status) 1199=item aio_rmtree $pathname, $callback->($status)
1083 1200
1084Delete a directory tree starting (and including) C<$path>, return the 1201Delete a directory tree starting (and including) C<$path>, return the
1085status 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
1086uses C<aio_scandir> to recurse into and rmdir directories, and unlink 1203uses C<aio_scandir> to recurse into and rmdir directories, and unlink
1087everything else. 1204everything else.
1088 1205
1089=cut 1206=cut
1090 1207
1111 add $grp $dirgrp; 1228 add $grp $dirgrp;
1112 }; 1229 };
1113 1230
1114 $grp 1231 $grp
1115} 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.
1116 1252
1117=item aio_sync $callback->($status) 1253=item aio_sync $callback->($status)
1118 1254
1119Asynchronously call sync and call the callback when finished. 1255Asynchronously call sync and call the callback when finished.
1120 1256
1210 1346
1211This is a rather advanced IO::AIO call, which works best on mmap(2)ed 1347This is a rather advanced IO::AIO call, which works best on mmap(2)ed
1212scalars. 1348scalars.
1213 1349
1214It touches (reads or writes) all memory pages in the specified 1350It touches (reads or writes) all memory pages in the specified
1215range inside the scalar. All caveats and parameters are the same 1351range inside the scalar. All caveats and parameters are the same
1216as for C<aio_msync>, above, except for flags, which must be either 1352as for C<aio_msync>, above, except for flags, which must be either
1217C<0> (which reads all pages and ensures they are instantiated) or 1353C<0> (which reads all pages and ensures they are instantiated) or
1218C<IO::AIO::MT_MODIFY>, which modifies the memory page s(by reading and 1354C<IO::AIO::MT_MODIFY>, which modifies the memory pages (by reading and
1219writing an octet from it, which dirties the page). 1355writing an octet from it, which dirties the page).
1220 1356
1221=item aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status) 1357=item aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status)
1222 1358
1223This is a rather advanced IO::AIO call, which works best on mmap(2)ed 1359This is a rather advanced IO::AIO call, which works best on mmap(2)ed
1257 1393
1258 aio_mlockall IO::AIO::MCL_FUTURE; 1394 aio_mlockall IO::AIO::MCL_FUTURE;
1259 1395
1260=item aio_fiemap $fh, $start, $length, $flags, $count, $cb->(\@extents) 1396=item aio_fiemap $fh, $start, $length, $flags, $count, $cb->(\@extents)
1261 1397
1262Queries the extents of the given file (by calling the Linux FIEMAP ioctl, 1398Queries the extents of the given file (by calling the Linux C<FIEMAP>
1263see L<http://cvs.schmorp.de/IO-AIO/doc/fiemap.txt> for details). If the 1399ioctl, see L<http://cvs.schmorp.de/IO-AIO/doc/fiemap.txt> for details). If
1264C<ioctl> is not available on your OS, then this rquiest will fail with 1400the ioctl is not available on your OS, then this request will fail with
1265C<ENOSYS>. 1401C<ENOSYS>.
1266 1402
1267C<$start> is the starting offset to query extents for, C<$length> is the 1403C<$start> is the starting offset to query extents for, C<$length> is the
1268size of the range to query - if it is C<undef>, then the whole file will 1404size of the range to query - if it is C<undef>, then the whole file will
1269be queried. 1405be queried.
1272C<IO::AIO::FIEMAP_FLAG_XATTR> - C<IO::AIO::FIEMAP_FLAGS_COMPAT> is also 1408C<IO::AIO::FIEMAP_FLAG_XATTR> - C<IO::AIO::FIEMAP_FLAGS_COMPAT> is also
1273exported), and is normally C<0> or C<IO::AIO::FIEMAP_FLAG_SYNC> to query 1409exported), and is normally C<0> or C<IO::AIO::FIEMAP_FLAG_SYNC> to query
1274the data portion. 1410the data portion.
1275 1411
1276C<$count> is the maximum number of extent records to return. If it is 1412C<$count> is the maximum number of extent records to return. If it is
1277C<undef>, then IO::AIO queries all extents of the file. As a very special 1413C<undef>, then IO::AIO queries all extents of the range. As a very special
1278case, if it is C<0>, then the callback receives the number of extents 1414case, if it is C<0>, then the callback receives the number of extents
1279instead of the extents themselves. 1415instead of the extents themselves (which is unreliable, see below).
1280 1416
1281If an error occurs, the callback receives no arguments. The special 1417If an error occurs, the callback receives no arguments. The special
1282C<errno> value C<IO::AIO::EBADR> is available to test for flag errors. 1418C<errno> value C<IO::AIO::EBADR> is available to test for flag errors.
1283 1419
1284Otherwise, the callback receives an array reference with extent 1420Otherwise, the callback receives an array reference with extent
1286following members: 1422following members:
1287 1423
1288 [$logical, $physical, $length, $flags] 1424 [$logical, $physical, $length, $flags]
1289 1425
1290Flags is any combination of the following flag values (typically either C<0> 1426Flags is any combination of the following flag values (typically either C<0>
1291or C<IO::AIO::FIEMAP_EXTENT_LAST>): 1427or C<IO::AIO::FIEMAP_EXTENT_LAST> (1)):
1292 1428
1293C<IO::AIO::FIEMAP_EXTENT_LAST>, C<IO::AIO::FIEMAP_EXTENT_UNKNOWN>, 1429C<IO::AIO::FIEMAP_EXTENT_LAST>, C<IO::AIO::FIEMAP_EXTENT_UNKNOWN>,
1294C<IO::AIO::FIEMAP_EXTENT_DELALLOC>, C<IO::AIO::FIEMAP_EXTENT_ENCODED>, 1430C<IO::AIO::FIEMAP_EXTENT_DELALLOC>, C<IO::AIO::FIEMAP_EXTENT_ENCODED>,
1295C<IO::AIO::FIEMAP_EXTENT_DATA_ENCRYPTED>, C<IO::AIO::FIEMAP_EXTENT_NOT_ALIGNED>, 1431C<IO::AIO::FIEMAP_EXTENT_DATA_ENCRYPTED>, C<IO::AIO::FIEMAP_EXTENT_NOT_ALIGNED>,
1296C<IO::AIO::FIEMAP_EXTENT_DATA_INLINE>, C<IO::AIO::FIEMAP_EXTENT_DATA_TAIL>, 1432C<IO::AIO::FIEMAP_EXTENT_DATA_INLINE>, C<IO::AIO::FIEMAP_EXTENT_DATA_TAIL>,
1297C<IO::AIO::FIEMAP_EXTENT_UNWRITTEN>, C<IO::AIO::FIEMAP_EXTENT_MERGED> or 1433C<IO::AIO::FIEMAP_EXTENT_UNWRITTEN>, C<IO::AIO::FIEMAP_EXTENT_MERGED> or
1298C<IO::AIO::FIEMAP_EXTENT_SHARED>. 1434C<IO::AIO::FIEMAP_EXTENT_SHARED>.
1299 1435
1436At the time of this writing (Linux 3.2), this requets is unreliable unless
1437C<$count> is C<undef>, as the kernel has all sorts of bugs preventing
1438it to return all extents of a range for files with large number of
1439extents. The code works around all these issues if C<$count> is undef.
1440
1300=item aio_group $callback->(...) 1441=item aio_group $callback->(...)
1301 1442
1302This is a very special aio request: Instead of doing something, it is a 1443This is a very special aio request: Instead of doing something, it is a
1303container for other aio requests, which is useful if you want to bundle 1444container for other aio requests, which is useful if you want to bundle
1304many requests into a single, composite, request with a definite callback 1445many requests into a single, composite, request with a definite callback
1387 aio_stat [$etcdir, "passwd"], sub { 1528 aio_stat [$etcdir, "passwd"], sub {
1388 # yay 1529 # yay
1389 }; 1530 };
1390 }; 1531 };
1391 1532
1392That C<aio_wd> is a request and not a normal function shows that creating 1533The fact that C<aio_wd> is a request and not a normal function shows that
1393an IO::AIO::WD object is itself a potentially blocking operation, which is 1534creating an IO::AIO::WD object is itself a potentially blocking operation,
1394why it is done asynchronously. 1535which is why it is done asynchronously.
1395 1536
1396To stat the directory obtained with C<aio_wd> above, one could write 1537To stat the directory obtained with C<aio_wd> above, one could write
1397either of the following three request calls: 1538either of the following three request calls:
1398 1539
1399 aio_lstat "/etc" , sub { ... # pathname as normal string 1540 aio_lstat "/etc" , sub { ... # pathname as normal string
1419will still point to the original directory. Most functions accepting a 1560will still point to the original directory. Most functions accepting a
1420pathname will use the directory fd on newer systems, and the string on 1561pathname will use the directory fd on newer systems, and the string on
1421older systems. Some functions (such as realpath) will always rely on the 1562older systems. Some functions (such as realpath) will always rely on the
1422string form of the pathname. 1563string form of the pathname.
1423 1564
1424So this fucntionality is mainly useful to get some protection against 1565So this functionality is mainly useful to get some protection against
1425C<chdir>, to easily get an absolute path out of a relative path for future 1566C<chdir>, to easily get an absolute path out of a relative path for future
1426reference, and to speed up doing many operations in the same directory 1567reference, and to speed up doing many operations in the same directory
1427(e.g. when stat'ing all files in a directory). 1568(e.g. when stat'ing all files in a directory).
1428 1569
1429The following functions implement this working directory abstraction: 1570The following functions implement this working directory abstraction:
1442passing C<undef> as working directory component of a pathname fails the 1583passing C<undef> as working directory component of a pathname fails the
1443request with C<ENOENT>, there is often no need for error checking in the 1584request with C<ENOENT>, there is often no need for error checking in the
1444C<aio_wd> callback, as future requests using the value will fail in the 1585C<aio_wd> callback, as future requests using the value will fail in the
1445expected way. 1586expected way.
1446 1587
1447If this call isn't available because your OS lacks it or it couldn't be
1448detected, it will be emulated by calling C<fsync> instead.
1449
1450=item IO::AIO::CWD 1588=item IO::AIO::CWD
1451 1589
1452This is a compiletime constant (object) that represents the process 1590This is a compiletime constant (object) that represents the process
1453current working directory. 1591current working directory.
1454 1592
1455Specifying this object as working directory object for a pathname is as 1593Specifying this object as working directory object for a pathname is as if
1456if the pathname would be specified directly, without a directory object, 1594the pathname would be specified directly, without a directory object. For
1457e.g., these calls are functionally identical: 1595example, these calls are functionally identical:
1458 1596
1459 aio_stat "somefile", sub { ... }; 1597 aio_stat "somefile", sub { ... };
1460 aio_stat [IO::AIO::CWD, "somefile"], sub { ... }; 1598 aio_stat [IO::AIO::CWD, "somefile"], sub { ... };
1461 1599
1462=back 1600=back
1463 1601
1602To recover the path associated with an IO::AIO::WD object, you can use
1603C<aio_realpath>:
1604
1605 aio_realpath $wd, sub {
1606 warn "path is $_[0]\n";
1607 };
1608
1609Currently, C<aio_statvfs> always, and C<aio_rename> and C<aio_rmdir>
1610sometimes, fall back to using an absolue path.
1464 1611
1465=head2 IO::AIO::REQ CLASS 1612=head2 IO::AIO::REQ CLASS
1466 1613
1467All non-aggregate C<aio_*> functions return an object of this class when 1614All non-aggregate C<aio_*> functions return an object of this class when
1468called in non-void context. 1615called in non-void context.
1646 1793
1647See C<poll_cb> for an example. 1794See C<poll_cb> for an example.
1648 1795
1649=item IO::AIO::poll_cb 1796=item IO::AIO::poll_cb
1650 1797
1651Process some outstanding events on the result pipe. You have to call 1798Process some requests that have reached the result phase (i.e. they have
1799been executed but the results are not yet reported). You have to call
1800this "regularly" to finish outstanding requests.
1801
1652this regularly. Returns C<0> if all events could be processed (or there 1802Returns C<0> if all events could be processed (or there were no
1653were no events to process), or C<-1> if it returned earlier for whatever 1803events to process), or C<-1> if it returned earlier for whatever
1654reason. Returns immediately when no events are outstanding. The amount of 1804reason. Returns immediately when no events are outstanding. The amount
1655events processed depends on the settings of C<IO::AIO::max_poll_req> and 1805of events processed depends on the settings of C<IO::AIO::max_poll_req>,
1656C<IO::AIO::max_poll_time>. 1806C<IO::AIO::max_poll_time> and C<IO::AIO::max_outstanding>.
1657 1807
1658If not all requests were processed for whatever reason, the filehandle 1808If not all requests were processed for whatever reason, the poll file
1659will still be ready when C<poll_cb> returns, so normally you don't have to 1809descriptor will still be ready when C<poll_cb> returns, so normally you
1660do anything special to have it called later. 1810don't have to do anything special to have it called later.
1661 1811
1662Apart from calling C<IO::AIO::poll_cb> when the event filehandle becomes 1812Apart from calling C<IO::AIO::poll_cb> when the event filehandle becomes
1663ready, it can be beneficial to call this function from loops which submit 1813ready, it can be beneficial to call this function from loops which submit
1664a lot of requests, to make sure the results get processed when they become 1814a lot of requests, to make sure the results get processed when they become
1665available and not just when the loop is finished and the event loop takes 1815available and not just when the loop is finished and the event loop takes
1674 poll => 'r', async => 1, 1824 poll => 'r', async => 1,
1675 cb => \&IO::AIO::poll_cb); 1825 cb => \&IO::AIO::poll_cb);
1676 1826
1677=item IO::AIO::poll_wait 1827=item IO::AIO::poll_wait
1678 1828
1679If there are any outstanding requests and none of them in the result 1829Wait until either at least one request is in the result phase or no
1680phase, wait till the result filehandle becomes ready for reading (simply 1830requests are outstanding anymore.
1681does a C<select> on the filehandle. This is useful if you want to 1831
1682synchronously wait for some requests to finish). 1832This is useful if you want to synchronously wait for some requests to
1833become ready, without actually handling them.
1683 1834
1684See C<nreqs> for an example. 1835See C<nreqs> for an example.
1685 1836
1686=item IO::AIO::poll 1837=item IO::AIO::poll
1687 1838
1808 1959
1809This is a very bad function to use in interactive programs because it 1960This is a very bad function to use in interactive programs because it
1810blocks, and a bad way to reduce concurrency because it is inexact: Better 1961blocks, and a bad way to reduce concurrency because it is inexact: Better
1811use an C<aio_group> together with a feed callback. 1962use an C<aio_group> together with a feed callback.
1812 1963
1813It's main use is in scripts without an event loop - when you want to stat 1964Its main use is in scripts without an event loop - when you want to stat
1814a lot of files, you can write somehting like this: 1965a lot of files, you can write somehting like this:
1815 1966
1816 IO::AIO::max_outstanding 32; 1967 IO::AIO::max_outstanding 32;
1817 1968
1818 for my $path (...) { 1969 for my $path (...) {
1858 2009
1859=back 2010=back
1860 2011
1861=head3 MISCELLANEOUS FUNCTIONS 2012=head3 MISCELLANEOUS FUNCTIONS
1862 2013
1863IO::AIO implements some functions that might be useful, but are not 2014IO::AIO implements some functions that are useful when you want to use
1864asynchronous. 2015some "Advanced I/O" function not available to in Perl, without going the
2016"Asynchronous I/O" route. Many of these have an asynchronous C<aio_*>
2017counterpart.
1865 2018
1866=over 4 2019=over 4
1867 2020
1868=item IO::AIO::sendfile $ofh, $ifh, $offset, $count 2021=item IO::AIO::sendfile $ofh, $ifh, $offset, $count
1869 2022
1906ENOSYS, otherwise the return value of C<mprotect>. 2059ENOSYS, otherwise the return value of C<mprotect>.
1907 2060
1908=item IO::AIO::mmap $scalar, $length, $prot, $flags, $fh[, $offset] 2061=item IO::AIO::mmap $scalar, $length, $prot, $flags, $fh[, $offset]
1909 2062
1910Memory-maps a file (or anonymous memory range) and attaches it to the 2063Memory-maps a file (or anonymous memory range) and attaches it to the
1911given C<$scalar>, which will act like a string scalar. 2064given C<$scalar>, which will act like a string scalar. Returns true on
2065success, and false otherwise.
1912 2066
1913The only operations allowed on the scalar are C<substr>/C<vec> that don't 2067The only operations allowed on the scalar are C<substr>/C<vec> that don't
1914change the string length, and most read-only operations such as copying it 2068change the string length, and most read-only operations such as copying it
1915or searching it with regexes and so on. 2069or searching it with regexes and so on.
1916 2070
1927filesize. 2081filesize.
1928 2082
1929C<$prot> is a combination of C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_EXEC>, 2083C<$prot> is a combination of C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_EXEC>,
1930C<IO::AIO::PROT_READ> and/or C<IO::AIO::PROT_WRITE>, 2084C<IO::AIO::PROT_READ> and/or C<IO::AIO::PROT_WRITE>,
1931 2085
1932C<$flags> can be a combination of C<IO::AIO::MAP_SHARED> or 2086C<$flags> can be a combination of
1933C<IO::AIO::MAP_PRIVATE>, or a number of system-specific flags (when 2087C<IO::AIO::MAP_SHARED> or
1934not available, the are defined as 0): C<IO::AIO::MAP_ANONYMOUS> 2088C<IO::AIO::MAP_PRIVATE>,
2089or a number of system-specific flags (when not available, the are C<0>):
1935(which is set to C<MAP_ANON> if your system only provides this 2090C<IO::AIO::MAP_ANONYMOUS> (which is set to C<MAP_ANON> if your system only provides this constant),
1936constant), C<IO::AIO::MAP_HUGETLB>, C<IO::AIO::MAP_LOCKED>, 2091C<IO::AIO::MAP_LOCKED>,
1937C<IO::AIO::MAP_NORESERVE>, C<IO::AIO::MAP_POPULATE> or 2092C<IO::AIO::MAP_NORESERVE>,
2093C<IO::AIO::MAP_POPULATE>,
1938C<IO::AIO::MAP_NONBLOCK> 2094C<IO::AIO::MAP_NONBLOCK>,
2095C<IO::AIO::MAP_FIXED>,
2096C<IO::AIO::MAP_GROWSDOWN>,
2097C<IO::AIO::MAP_32BIT>,
2098C<IO::AIO::MAP_HUGETLB> or
2099C<IO::AIO::MAP_STACK>.
1939 2100
1940If C<$fh> is C<undef>, then a file descriptor of C<-1> is passed. 2101If C<$fh> is C<undef>, then a file descriptor of C<-1> is passed.
1941 2102
1942C<$offset> is the offset from the start of the file - it generally must be 2103C<$offset> is the offset from the start of the file - it generally must be
1943a multiple of C<IO::AIO::PAGESIZE> and defaults to C<0>. 2104a multiple of C<IO::AIO::PAGESIZE> and defaults to C<0>.
1975 2136
1976Calls the GNU/Linux C<splice(2)> syscall, if available. If C<$r_off> or 2137Calls the GNU/Linux C<splice(2)> syscall, if available. If C<$r_off> or
1977C<$w_off> are C<undef>, then C<NULL> is passed for these, otherwise they 2138C<$w_off> are C<undef>, then C<NULL> is passed for these, otherwise they
1978should be the file offset. 2139should be the file offset.
1979 2140
2141C<$r_fh> and C<$w_fh> should not refer to the same file, as splice might
2142silently corrupt the data in this case.
2143
1980The following symbol flag values are available: C<IO::AIO::SPLICE_F_MOVE>, 2144The following symbol flag values are available: C<IO::AIO::SPLICE_F_MOVE>,
1981C<IO::AIO::SPLICE_F_NONBLOCK>, C<IO::AIO::SPLICE_F_MORE> and 2145C<IO::AIO::SPLICE_F_NONBLOCK>, C<IO::AIO::SPLICE_F_MORE> and
1982C<IO::AIO::SPLICE_F_GIFT>. 2146C<IO::AIO::SPLICE_F_GIFT>.
1983 2147
1984See the C<splice(2)> manpage for details. 2148See the C<splice(2)> manpage for details.
1985 2149
1986=item IO::AIO::tee $r_fh, $w_fh, $length, $flags 2150=item IO::AIO::tee $r_fh, $w_fh, $length, $flags
1987 2151
1988Calls the GNU/Linux C<tee(2)> syscall, see it's manpage and the 2152Calls the GNU/Linux C<tee(2)> syscall, see its manpage and the
1989description for C<IO::AIO::splice> above for details. 2153description for C<IO::AIO::splice> above for details.
2154
2155=item $actual_size = IO::AIO::pipesize $r_fh[, $new_size]
2156
2157Attempts to query or change the pipe buffer size. Obviously works only
2158on pipes, and currently works only on GNU/Linux systems, and fails with
2159C<-1>/C<ENOSYS> everywhere else. If anybody knows how to influence pipe buffer
2160size on other systems, drop me a note.
2161
2162=item ($rfh, $wfh) = IO::AIO::pipe2 [$flags]
2163
2164This is a direct interface to the Linux L<pipe2(2)> system call. If
2165C<$flags> is missing or C<0>, then this should be the same as a call to
2166perl's built-in C<pipe> function and create a new pipe, and works on
2167systems that lack the pipe2 syscall. On win32, this case invokes C<_pipe
2168(..., 4096, O_BINARY)>.
2169
2170If C<$flags> is non-zero, it tries to invoke the pipe2 system call with
2171the given flags (Linux 2.6.27, glibc 2.9).
2172
2173On success, the read and write file handles are returned.
2174
2175On error, nothing will be returned. If the pipe2 syscall is missing and
2176C<$flags> is non-zero, fails with C<ENOSYS>.
2177
2178Please refer to L<pipe2(2)> for more info on the C<$flags>, but at the
2179time of this writing, C<IO::AIO::O_CLOEXEC>, C<IO::AIO::O_NONBLOCK> and
2180C<IO::AIO::O_DIRECT> (Linux 3.4, for packet-based pipes) were supported.
1990 2181
1991=back 2182=back
1992 2183
1993=cut 2184=cut
1994 2185

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