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Comparing IO-AIO/AIO.pm (file contents):
Revision 1.206 by root, Sun Jul 24 03:32:51 2011 UTC vs.
Revision 1.241 by root, Fri Dec 28 07:33:41 2012 UTC

168use common::sense; 168use common::sense;
169 169
170use base 'Exporter'; 170use base 'Exporter';
171 171
172BEGIN { 172BEGIN {
173 our $VERSION = '4.0'; 173 our $VERSION = '4.18';
174 174
175 our @AIO_REQ = qw(aio_sendfile aio_read aio_write aio_open aio_close 175 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 176 aio_stat aio_lstat aio_unlink aio_rmdir aio_readdir aio_readdirx
177 aio_scandir aio_symlink aio_readlink aio_realpath aio_sync 177 aio_scandir aio_symlink aio_readlink aio_realpath aio_sync
178 aio_fsync aio_syncfs aio_fdatasync aio_sync_file_range aio_fallocate 178 aio_fsync aio_syncfs aio_fdatasync aio_sync_file_range aio_allocate
179 aio_pathsync aio_readahead 179 aio_pathsync aio_readahead aio_fiemap
180 aio_rename aio_link aio_move aio_copy aio_group 180 aio_rename aio_link aio_move aio_copy aio_group
181 aio_nop aio_mknod aio_load aio_rmtree aio_mkdir aio_chown 181 aio_nop aio_mknod aio_load aio_rmtree aio_mkdir aio_chown
182 aio_chmod aio_utime aio_truncate 182 aio_chmod aio_utime aio_truncate
183 aio_msync aio_mtouch aio_mlock aio_mlockall 183 aio_msync aio_mtouch aio_mlock aio_mlockall
184 aio_statvfs); 184 aio_statvfs
185 aio_wd);
185 186
186 our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice)); 187 our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice));
187 our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush 188 our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush
188 min_parallel max_parallel max_idle idle_timeout 189 min_parallel max_parallel max_idle idle_timeout
189 nreqs nready npending nthreads 190 nreqs nready npending nthreads
201 202
202=head1 FUNCTIONS 203=head1 FUNCTIONS
203 204
204=head2 QUICK OVERVIEW 205=head2 QUICK OVERVIEW
205 206
206This section simply lists the prototypes of the most important functions 207This section simply lists the prototypes most of the functions for
207for quick reference. See the following sections for function-by-function 208quick reference. See the following sections for function-by-function
208documentation. 209documentation.
209 210
211 aio_wd $pathname, $callback->($wd)
210 aio_open $pathname, $flags, $mode, $callback->($fh) 212 aio_open $pathname, $flags, $mode, $callback->($fh)
211 aio_close $fh, $callback->($status) 213 aio_close $fh, $callback->($status)
214 aio_seek $fh,$offset,$whence, $callback->($offs)
212 aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval) 215 aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
213 aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval) 216 aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
214 aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval) 217 aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval)
215 aio_readahead $fh,$offset,$length, $callback->($retval) 218 aio_readahead $fh,$offset,$length, $callback->($retval)
216 aio_stat $fh_or_path, $callback->($status) 219 aio_stat $fh_or_path, $callback->($status)
217 aio_lstat $fh, $callback->($status) 220 aio_lstat $fh, $callback->($status)
218 aio_statvfs $fh_or_path, $callback->($statvfs) 221 aio_statvfs $fh_or_path, $callback->($statvfs)
219 aio_utime $fh_or_path, $atime, $mtime, $callback->($status) 222 aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
220 aio_chown $fh_or_path, $uid, $gid, $callback->($status) 223 aio_chown $fh_or_path, $uid, $gid, $callback->($status)
224 aio_chmod $fh_or_path, $mode, $callback->($status)
221 aio_truncate $fh_or_path, $offset, $callback->($status) 225 aio_truncate $fh_or_path, $offset, $callback->($status)
222 aio_chmod $fh_or_path, $mode, $callback->($status) 226 aio_allocate $fh, $mode, $offset, $len, $callback->($status)
227 aio_fiemap $fh, $start, $length, $flags, $count, $cb->(\@extents)
223 aio_unlink $pathname, $callback->($status) 228 aio_unlink $pathname, $callback->($status)
224 aio_mknod $path, $mode, $dev, $callback->($status) 229 aio_mknod $pathname, $mode, $dev, $callback->($status)
225 aio_link $srcpath, $dstpath, $callback->($status) 230 aio_link $srcpath, $dstpath, $callback->($status)
226 aio_symlink $srcpath, $dstpath, $callback->($status) 231 aio_symlink $srcpath, $dstpath, $callback->($status)
227 aio_readlink $path, $callback->($link) 232 aio_readlink $pathname, $callback->($link)
228 aio_realpath $path, $callback->($link) 233 aio_realpath $pathname, $callback->($link)
229 aio_rename $srcpath, $dstpath, $callback->($status) 234 aio_rename $srcpath, $dstpath, $callback->($status)
230 aio_mkdir $pathname, $mode, $callback->($status) 235 aio_mkdir $pathname, $mode, $callback->($status)
231 aio_rmdir $pathname, $callback->($status) 236 aio_rmdir $pathname, $callback->($status)
232 aio_readdir $pathname, $callback->($entries) 237 aio_readdir $pathname, $callback->($entries)
233 aio_readdirx $pathname, $flags, $callback->($entries, $flags) 238 aio_readdirx $pathname, $flags, $callback->($entries, $flags)
234 IO::AIO::READDIR_DENTS IO::AIO::READDIR_DIRS_FIRST 239 IO::AIO::READDIR_DENTS IO::AIO::READDIR_DIRS_FIRST
235 IO::AIO::READDIR_STAT_ORDER IO::AIO::READDIR_FOUND_UNKNOWN 240 IO::AIO::READDIR_STAT_ORDER IO::AIO::READDIR_FOUND_UNKNOWN
241 aio_scandir $pathname, $maxreq, $callback->($dirs, $nondirs)
236 aio_load $path, $data, $callback->($status) 242 aio_load $pathname, $data, $callback->($status)
237 aio_copy $srcpath, $dstpath, $callback->($status) 243 aio_copy $srcpath, $dstpath, $callback->($status)
238 aio_move $srcpath, $dstpath, $callback->($status) 244 aio_move $srcpath, $dstpath, $callback->($status)
239 aio_scandir $path, $maxreq, $callback->($dirs, $nondirs)
240 aio_rmtree $path, $callback->($status) 245 aio_rmtree $pathname, $callback->($status)
241 aio_sync $callback->($status) 246 aio_sync $callback->($status)
242 aio_syncfs $fh, $callback->($status) 247 aio_syncfs $fh, $callback->($status)
243 aio_fsync $fh, $callback->($status) 248 aio_fsync $fh, $callback->($status)
244 aio_fdatasync $fh, $callback->($status) 249 aio_fdatasync $fh, $callback->($status)
245 aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status) 250 aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status)
246 aio_pathsync $path, $callback->($status) 251 aio_pathsync $pathname, $callback->($status)
247 aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status) 252 aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
248 aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status) 253 aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
249 aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status) 254 aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status)
250 aio_mlockall $flags, $callback->($status) 255 aio_mlockall $flags, $callback->($status)
251 aio_group $callback->(...) 256 aio_group $callback->(...)
269 IO::AIO::nready 274 IO::AIO::nready
270 IO::AIO::npending 275 IO::AIO::npending
271 276
272 IO::AIO::sendfile $ofh, $ifh, $offset, $count 277 IO::AIO::sendfile $ofh, $ifh, $offset, $count
273 IO::AIO::fadvise $fh, $offset, $len, $advice 278 IO::AIO::fadvise $fh, $offset, $len, $advice
279 IO::AIO::mmap $scalar, $length, $prot, $flags[, $fh[, $offset]]
280 IO::AIO::munmap $scalar
274 IO::AIO::madvise $scalar, $offset, $length, $advice 281 IO::AIO::madvise $scalar, $offset, $length, $advice
275 IO::AIO::mprotect $scalar, $offset, $length, $protect 282 IO::AIO::mprotect $scalar, $offset, $length, $protect
276 IO::AIO::munlock $scalar, $offset = 0, $length = undef 283 IO::AIO::munlock $scalar, $offset = 0, $length = undef
277 IO::AIO::munlockall 284 IO::AIO::munlockall
278 285
279=head2 AIO REQUEST FUNCTIONS 286=head2 API NOTES
280 287
281All the C<aio_*> calls are more or less thin wrappers around the syscall 288All the C<aio_*> calls are more or less thin wrappers around the syscall
282with the same name (sans C<aio_>). The arguments are similar or identical, 289with the same name (sans C<aio_>). The arguments are similar or identical,
283and they all accept an additional (and optional) C<$callback> argument 290and they all accept an additional (and optional) C<$callback> argument
284which must be a code reference. This code reference will get called with 291which must be a code reference. This code reference will be called after
285the syscall return code (e.g. most syscalls return C<-1> on error, unlike 292the syscall has been executed in an asynchronous fashion. The results
286perl, which usually delivers "false") as its sole argument after the given 293of the request will be passed as arguments to the callback (and, if an
287syscall has been executed asynchronously. 294error occured, in C<$!>) - for most requests the syscall return code (e.g.
295most syscalls return C<-1> on error, unlike perl, which usually delivers
296"false").
297
298Some requests (such as C<aio_readdir>) pass the actual results and
299communicate failures by passing C<undef>.
288 300
289All functions expecting a filehandle keep a copy of the filehandle 301All functions expecting a filehandle keep a copy of the filehandle
290internally until the request has finished. 302internally until the request has finished.
291 303
292All functions return request objects of type L<IO::AIO::REQ> that allow 304All functions return request objects of type L<IO::AIO::REQ> that allow
293further manipulation of those requests while they are in-flight. 305further manipulation of those requests while they are in-flight.
294 306
295The pathnames you pass to these routines I<must> be absolute and 307The pathnames you pass to these routines I<should> be absolute. The
296encoded as octets. The reason for the former is that at the time the 308reason for this is that at the time the request is being executed, the
297request is being executed, the current working directory could have 309current working directory could have changed. Alternatively, you can
298changed. Alternatively, you can make sure that you never change the 310make sure that you never change the current working directory anywhere
299current working directory anywhere in the program and then use relative 311in the program and then use relative paths. You can also take advantage
300paths. 312of IO::AIOs working directory abstraction, that lets you specify paths
313relative to some previously-opened "working directory object" - see the
314description of the C<IO::AIO::WD> class later in this document.
301 315
302To encode pathnames as octets, either make sure you either: a) always pass 316To encode pathnames as octets, either make sure you either: a) always pass
303in filenames you got from outside (command line, readdir etc.) without 317in filenames you got from outside (command line, readdir etc.) without
304tinkering, b) are ASCII or ISO 8859-1, c) use the Encode module and encode 318tinkering, b) are in your native filesystem encoding, c) use the Encode
305your pathnames to the locale (or other) encoding in effect in the user 319module and encode your pathnames to the locale (or other) encoding in
306environment, d) use Glib::filename_from_unicode on unicode filenames or e) 320effect in the user environment, d) use Glib::filename_from_unicode on
307use something else to ensure your scalar has the correct contents. 321unicode filenames or e) use something else to ensure your scalar has the
322correct contents.
308 323
309This works, btw. independent of the internal UTF-8 bit, which IO::AIO 324This works, btw. independent of the internal UTF-8 bit, which IO::AIO
310handles correctly whether it is set or not. 325handles correctly whether it is set or not.
326
327=head2 AIO REQUEST FUNCTIONS
311 328
312=over 4 329=over 4
313 330
314=item $prev_pri = aioreq_pri [$pri] 331=item $prev_pri = aioreq_pri [$pri]
315 332
345 362
346 363
347=item aio_open $pathname, $flags, $mode, $callback->($fh) 364=item aio_open $pathname, $flags, $mode, $callback->($fh)
348 365
349Asynchronously open or create a file and call the callback with a newly 366Asynchronously open or create a file and call the callback with a newly
350created filehandle for the file. 367created filehandle for the file (or C<undef> in case of an error).
351 368
352The pathname passed to C<aio_open> must be absolute. See API NOTES, above, 369The pathname passed to C<aio_open> must be absolute. See API NOTES, above,
353for an explanation. 370for an explanation.
354 371
355The C<$flags> argument is a bitmask. See the C<Fcntl> module for a 372The C<$flags> argument is a bitmask. See the C<Fcntl> module for a
397 414
398Or in other words: the file descriptor will be closed, but it will not be 415Or in other words: the file descriptor will be closed, but it will not be
399free for reuse until the perl filehandle is closed. 416free for reuse until the perl filehandle is closed.
400 417
401=cut 418=cut
419
420=item aio_seek $fh, $offset, $whence, $callback->($offs)
421
422Seeks the filehandle to the new C<$offset>, similarly to perl's
423C<sysseek>. The C<$whence> can use the traditional values (C<0> for
424C<IO::AIO::SEEK_SET>, C<1> for C<IO::AIO::SEEK_CUR> or C<2> for
425C<IO::AIO::SEEK_END>).
426
427The resulting absolute offset will be passed to the callback, or C<-1> in
428case of an error.
429
430In theory, the C<$whence> constants could be different than the
431corresponding values from L<Fcntl>, but perl guarantees they are the same,
432so don't panic.
433
434As a GNU/Linux (and maybe Solaris) extension, also the constants
435C<IO::AIO::SEEK_DATA> and C<IO::AIO::SEEK_HOLE> are available, if they
436could be found. No guarantees about suitability for use in C<aio_seek> or
437Perl's C<sysseek> can be made though, although I would naively assume they
438"just work".
402 439
403=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval) 440=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
404 441
405=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval) 442=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
406 443
566 namemax => 255, 603 namemax => 255,
567 frsize => 1024, 604 frsize => 1024,
568 fsid => 1810 605 fsid => 1810
569 } 606 }
570 607
608Here is a (likely partial) list of fsid values used by Linux - it is safe
609to hardcode these when the $^O is C<linux>:
610
611 0x0000adf5 adfs
612 0x0000adff affs
613 0x5346414f afs
614 0x09041934 anon-inode filesystem
615 0x00000187 autofs
616 0x42465331 befs
617 0x1badface bfs
618 0x42494e4d binfmt_misc
619 0x9123683e btrfs
620 0x0027e0eb cgroupfs
621 0xff534d42 cifs
622 0x73757245 coda
623 0x012ff7b7 coh
624 0x28cd3d45 cramfs
625 0x453dcd28 cramfs-wend (wrong endianness)
626 0x64626720 debugfs
627 0x00001373 devfs
628 0x00001cd1 devpts
629 0x0000f15f ecryptfs
630 0x00414a53 efs
631 0x0000137d ext
632 0x0000ef53 ext2/ext3
633 0x0000ef51 ext2
634 0x00004006 fat
635 0x65735546 fuseblk
636 0x65735543 fusectl
637 0x0bad1dea futexfs
638 0x01161970 gfs2
639 0x47504653 gpfs
640 0x00004244 hfs
641 0xf995e849 hpfs
642 0x958458f6 hugetlbfs
643 0x2bad1dea inotifyfs
644 0x00009660 isofs
645 0x000072b6 jffs2
646 0x3153464a jfs
647 0x6b414653 k-afs
648 0x0bd00bd0 lustre
649 0x0000137f minix
650 0x0000138f minix 30 char names
651 0x00002468 minix v2
652 0x00002478 minix v2 30 char names
653 0x00004d5a minix v3
654 0x19800202 mqueue
655 0x00004d44 msdos
656 0x0000564c novell
657 0x00006969 nfs
658 0x6e667364 nfsd
659 0x00003434 nilfs
660 0x5346544e ntfs
661 0x00009fa1 openprom
662 0x7461636F ocfs2
663 0x00009fa0 proc
664 0x6165676c pstorefs
665 0x0000002f qnx4
666 0x858458f6 ramfs
667 0x52654973 reiserfs
668 0x00007275 romfs
669 0x67596969 rpc_pipefs
670 0x73636673 securityfs
671 0xf97cff8c selinux
672 0x0000517b smb
673 0x534f434b sockfs
674 0x73717368 squashfs
675 0x62656572 sysfs
676 0x012ff7b6 sysv2
677 0x012ff7b5 sysv4
678 0x01021994 tmpfs
679 0x15013346 udf
680 0x00011954 ufs
681 0x54190100 ufs byteswapped
682 0x00009fa2 usbdevfs
683 0x01021997 v9fs
684 0xa501fcf5 vxfs
685 0xabba1974 xenfs
686 0x012ff7b4 xenix
687 0x58465342 xfs
688 0x012fd16d xia
571 689
572=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status) 690=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
573 691
574Works like perl's C<utime> function (including the special case of $atime 692Works like perl's C<utime> function (including the special case of $atime
575and $mtime being undef). Fractional times are supported if the underlying 693and $mtime being undef). Fractional times are supported if the underlying
603=item aio_truncate $fh_or_path, $offset, $callback->($status) 721=item aio_truncate $fh_or_path, $offset, $callback->($status)
604 722
605Works like truncate(2) or ftruncate(2). 723Works like truncate(2) or ftruncate(2).
606 724
607 725
726=item aio_allocate $fh, $mode, $offset, $len, $callback->($status)
727
728Allocates or freed disk space according to the C<$mode> argument. See the
729linux C<fallocate> docuemntation for details.
730
731C<$mode> can currently be C<0> or C<IO::AIO::FALLOC_FL_KEEP_SIZE>
732to allocate space, or C<IO::AIO::FALLOC_FL_PUNCH_HOLE |
733IO::AIO::FALLOC_FL_KEEP_SIZE>, to deallocate a file range.
734
735The file system block size used by C<fallocate> is presumably the
736C<f_bsize> returned by C<statvfs>.
737
738If C<fallocate> isn't available or cannot be emulated (currently no
739emulation will be attempted), passes C<-1> and sets C<$!> to C<ENOSYS>.
740
741
608=item aio_chmod $fh_or_path, $mode, $callback->($status) 742=item aio_chmod $fh_or_path, $mode, $callback->($status)
609 743
610Works like perl's C<chmod> function. 744Works like perl's C<chmod> function.
611 745
612 746
614 748
615Asynchronously unlink (delete) a file and call the callback with the 749Asynchronously unlink (delete) a file and call the callback with the
616result code. 750result code.
617 751
618 752
619=item aio_mknod $path, $mode, $dev, $callback->($status) 753=item aio_mknod $pathname, $mode, $dev, $callback->($status)
620 754
621[EXPERIMENTAL] 755[EXPERIMENTAL]
622 756
623Asynchronously create a device node (or fifo). See mknod(2). 757Asynchronously create a device node (or fifo). See mknod(2).
624 758
625The only (POSIX-) portable way of calling this function is: 759The only (POSIX-) portable way of calling this function is:
626 760
627 aio_mknod $path, IO::AIO::S_IFIFO | $mode, 0, sub { ... 761 aio_mknod $pathname, IO::AIO::S_IFIFO | $mode, 0, sub { ...
628 762
629See C<aio_stat> for info about some potentially helpful extra constants 763See C<aio_stat> for info about some potentially helpful extra constants
630and functions. 764and functions.
631 765
632=item aio_link $srcpath, $dstpath, $callback->($status) 766=item aio_link $srcpath, $dstpath, $callback->($status)
639 773
640Asynchronously create a new symbolic link to the existing object at C<$srcpath> at 774Asynchronously create a new symbolic link to the existing object at C<$srcpath> at
641the path C<$dstpath> and call the callback with the result code. 775the path C<$dstpath> and call the callback with the result code.
642 776
643 777
644=item aio_readlink $path, $callback->($link) 778=item aio_readlink $pathname, $callback->($link)
645 779
646Asynchronously read the symlink specified by C<$path> and pass it to 780Asynchronously read the symlink specified by C<$path> and pass it to
647the callback. If an error occurs, nothing or undef gets passed to the 781the callback. If an error occurs, nothing or undef gets passed to the
648callback. 782callback.
649 783
650 784
651=item aio_realpath $path, $callback->($path) 785=item aio_realpath $pathname, $callback->($path)
652 786
653Asynchronously make the path absolute and resolve any symlinks in 787Asynchronously make the path absolute and resolve any symlinks in
654C<$path>. The resulting path only consists of directories (Same as 788C<$path>. The resulting path only consists of directories (same as
655L<Cwd::realpath>). 789L<Cwd::realpath>).
656 790
657This request can be used to get the absolute path of the current working 791This request can be used to get the absolute path of the current working
658directory by passing it a path of F<.> (a single dot). 792directory by passing it a path of F<.> (a single dot).
659 793
660 794
661=item aio_rename $srcpath, $dstpath, $callback->($status) 795=item aio_rename $srcpath, $dstpath, $callback->($status)
662 796
663Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as 797Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as
664rename(2) and call the callback with the result code. 798rename(2) and call the callback with the result code.
799
800On systems that support the AIO::WD working directory abstraction
801natively, the case C<[$wd, "."]> as C<$srcpath> is specialcased - instead
802of failing, C<rename> is called on the absolute path of C<$wd>.
665 803
666 804
667=item aio_mkdir $pathname, $mode, $callback->($status) 805=item aio_mkdir $pathname, $mode, $callback->($status)
668 806
669Asynchronously mkdir (create) a directory and call the callback with 807Asynchronously mkdir (create) a directory and call the callback with
674=item aio_rmdir $pathname, $callback->($status) 812=item aio_rmdir $pathname, $callback->($status)
675 813
676Asynchronously rmdir (delete) a directory and call the callback with the 814Asynchronously rmdir (delete) a directory and call the callback with the
677result code. 815result code.
678 816
817On systems that support the AIO::WD working directory abstraction
818natively, the case C<[$wd, "."]> is specialcased - instead of failing,
819C<rmdir> is called on the absolute path of C<$wd>.
820
679 821
680=item aio_readdir $pathname, $callback->($entries) 822=item aio_readdir $pathname, $callback->($entries)
681 823
682Unlike the POSIX call of the same name, C<aio_readdir> reads an entire 824Unlike the POSIX call of the same name, C<aio_readdir> reads an entire
683directory (i.e. opendir + readdir + closedir). The entries will not be 825directory (i.e. opendir + readdir + closedir). The entries will not be
687array-ref with the filenames. 829array-ref with the filenames.
688 830
689 831
690=item aio_readdirx $pathname, $flags, $callback->($entries, $flags) 832=item aio_readdirx $pathname, $flags, $callback->($entries, $flags)
691 833
692Quite similar to C<aio_readdir>, but the C<$flags> argument allows to tune 834Quite similar to C<aio_readdir>, but the C<$flags> argument allows one to
693behaviour and output format. In case of an error, C<$entries> will be 835tune behaviour and output format. In case of an error, C<$entries> will be
694C<undef>. 836C<undef>.
695 837
696The flags are a combination of the following constants, ORed together (the 838The flags are a combination of the following constants, ORed together (the
697flags will also be passed to the callback, possibly modified): 839flags will also be passed to the callback, possibly modified):
698 840
745 887
746=item IO::AIO::READDIR_FOUND_UNKNOWN 888=item IO::AIO::READDIR_FOUND_UNKNOWN
747 889
748This flag should not be set when calling C<aio_readdirx>. Instead, it 890This flag should not be set when calling C<aio_readdirx>. Instead, it
749is being set by C<aio_readdirx>, when any of the C<$type>'s found were 891is being set by C<aio_readdirx>, when any of the C<$type>'s found were
750C<IO::AIO::DT_UNKNOWN>. The absense of this flag therefore indicates that all 892C<IO::AIO::DT_UNKNOWN>. The absence of this flag therefore indicates that all
751C<$type>'s are known, which can be used to speed up some algorithms. 893C<$type>'s are known, which can be used to speed up some algorithms.
752 894
753=back 895=back
754 896
755 897
756=item aio_load $path, $data, $callback->($status) 898=item aio_load $pathname, $data, $callback->($status)
757 899
758This is a composite request that tries to fully load the given file into 900This is a composite request that tries to fully load the given file into
759memory. Status is the same as with aio_read. 901memory. Status is the same as with aio_read.
760 902
761=cut 903=cut
896 }; 1038 };
897 1039
898 $grp 1040 $grp
899} 1041}
900 1042
901=item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs) 1043=item aio_scandir $pathname, $maxreq, $callback->($dirs, $nondirs)
902 1044
903Scans a directory (similar to C<aio_readdir>) but additionally tries to 1045Scans a directory (similar to C<aio_readdir>) but additionally tries to
904efficiently separate the entries of directory C<$path> into two sets of 1046efficiently separate the entries of directory C<$path> into two sets of
905names, directories you can recurse into (directories), and ones you cannot 1047names, directories you can recurse into (directories), and ones you cannot
906recurse into (everything else, including symlinks to directories). 1048recurse into (everything else, including symlinks to directories).
937Then entries will be sorted into likely directories a non-initial dot 1079Then entries will be sorted into likely directories a non-initial dot
938currently) and likely non-directories (see C<aio_readdirx>). Then every 1080currently) and likely non-directories (see C<aio_readdirx>). Then every
939entry plus an appended C</.> will be C<stat>'ed, likely directories first, 1081entry plus an appended C</.> will be C<stat>'ed, likely directories first,
940in order of their inode numbers. If that succeeds, it assumes that the 1082in order of their inode numbers. If that succeeds, it assumes that the
941entry is a directory or a symlink to directory (which will be checked 1083entry is a directory or a symlink to directory (which will be checked
942seperately). This is often faster than stat'ing the entry itself because 1084separately). This is often faster than stat'ing the entry itself because
943filesystems might detect the type of the entry without reading the inode 1085filesystems might detect the type of the entry without reading the inode
944data (e.g. ext2fs filetype feature), even on systems that cannot return 1086data (e.g. ext2fs filetype feature), even on systems that cannot return
945the filetype information on readdir. 1087the filetype information on readdir.
946 1088
947If the known number of directories (link count - 2) has been reached, the 1089If the known number of directories (link count - 2) has been reached, the
963 1105
964 my $grp = aio_group $cb; 1106 my $grp = aio_group $cb;
965 1107
966 $maxreq = 4 if $maxreq <= 0; 1108 $maxreq = 4 if $maxreq <= 0;
967 1109
968 # stat once 1110 # get a wd object
969 aioreq_pri $pri; 1111 aioreq_pri $pri;
970 add $grp aio_stat $path, sub { 1112 add $grp aio_wd $path, sub {
1113 $_[0]
971 return $grp->result () if $_[0]; 1114 or return $grp->result ();
972 my $now = time;
973 my $hash1 = join ":", (stat _)[0,1,3,7,9];
974 1115
975 # read the directory entries 1116 my $wd = [shift, "."];
1117
1118 # stat once
976 aioreq_pri $pri; 1119 aioreq_pri $pri;
977 add $grp aio_readdirx $path, READDIR_DIRS_FIRST, sub { 1120 add $grp aio_stat $wd, sub {
978 my $entries = shift
979 or return $grp->result (); 1121 return $grp->result () if $_[0];
1122 my $now = time;
1123 my $hash1 = join ":", (stat _)[0,1,3,7,9];
980 1124
981 # stat the dir another time 1125 # read the directory entries
982 aioreq_pri $pri; 1126 aioreq_pri $pri;
1127 add $grp aio_readdirx $wd, READDIR_DIRS_FIRST, sub {
1128 my $entries = shift
1129 or return $grp->result ();
1130
1131 # stat the dir another time
1132 aioreq_pri $pri;
983 add $grp aio_stat $path, sub { 1133 add $grp aio_stat $wd, sub {
984 my $hash2 = join ":", (stat _)[0,1,3,7,9]; 1134 my $hash2 = join ":", (stat _)[0,1,3,7,9];
985 1135
986 my $ndirs; 1136 my $ndirs;
987 1137
988 # take the slow route if anything looks fishy 1138 # take the slow route if anything looks fishy
989 if ($hash1 ne $hash2 or (stat _)[9] == $now) { 1139 if ($hash1 ne $hash2 or (stat _)[9] == $now) {
990 $ndirs = -1; 1140 $ndirs = -1;
991 } else { 1141 } else {
992 # if nlink == 2, we are finished 1142 # if nlink == 2, we are finished
993 # for non-posix-fs's, we rely on nlink < 2 1143 # for non-posix-fs's, we rely on nlink < 2
994 $ndirs = (stat _)[3] - 2 1144 $ndirs = (stat _)[3] - 2
995 or return $grp->result ([], $entries); 1145 or return $grp->result ([], $entries);
996 } 1146 }
997 1147
998 my (@dirs, @nondirs); 1148 my (@dirs, @nondirs);
999 1149
1000 my $statgrp = add $grp aio_group sub { 1150 my $statgrp = add $grp aio_group sub {
1001 $grp->result (\@dirs, \@nondirs); 1151 $grp->result (\@dirs, \@nondirs);
1002 }; 1152 };
1003 1153
1004 limit $statgrp $maxreq; 1154 limit $statgrp $maxreq;
1005 feed $statgrp sub { 1155 feed $statgrp sub {
1006 return unless @$entries; 1156 return unless @$entries;
1007 my $entry = shift @$entries; 1157 my $entry = shift @$entries;
1008 1158
1009 aioreq_pri $pri; 1159 aioreq_pri $pri;
1160 $wd->[1] = "$entry/.";
1010 add $statgrp aio_stat "$path/$entry/.", sub { 1161 add $statgrp aio_stat $wd, sub {
1011 if ($_[0] < 0) { 1162 if ($_[0] < 0) {
1012 push @nondirs, $entry; 1163 push @nondirs, $entry;
1013 } else { 1164 } else {
1014 # need to check for real directory 1165 # need to check for real directory
1015 aioreq_pri $pri; 1166 aioreq_pri $pri;
1167 $wd->[1] = $entry;
1016 add $statgrp aio_lstat "$path/$entry", sub { 1168 add $statgrp aio_lstat $wd, sub {
1017 if (-d _) { 1169 if (-d _) {
1018 push @dirs, $entry; 1170 push @dirs, $entry;
1019 1171
1020 unless (--$ndirs) { 1172 unless (--$ndirs) {
1021 push @nondirs, @$entries; 1173 push @nondirs, @$entries;
1022 feed $statgrp; 1174 feed $statgrp;
1175 }
1176 } else {
1177 push @nondirs, $entry;
1023 } 1178 }
1024 } else {
1025 push @nondirs, $entry;
1026 } 1179 }
1027 } 1180 }
1028 } 1181 };
1029 }; 1182 };
1030 }; 1183 };
1031 }; 1184 };
1032 }; 1185 };
1033 }; 1186 };
1034 1187
1035 $grp 1188 $grp
1036} 1189}
1037 1190
1038=item aio_rmtree $path, $callback->($status) 1191=item aio_rmtree $pathname, $callback->($status)
1039 1192
1040Delete a directory tree starting (and including) C<$path>, return the 1193Delete a directory tree starting (and including) C<$path>, return the
1041status of the final C<rmdir> only. This is a composite request that 1194status of the final C<rmdir> only. This is a composite request that
1042uses C<aio_scandir> to recurse into and rmdir directories, and unlink 1195uses C<aio_scandir> to recurse into and rmdir directories, and unlink
1043everything else. 1196everything else.
1044 1197
1045=cut 1198=cut
1046 1199
1104C<$flags> can be a combination of C<IO::AIO::SYNC_FILE_RANGE_WAIT_BEFORE>, 1257C<$flags> can be a combination of C<IO::AIO::SYNC_FILE_RANGE_WAIT_BEFORE>,
1105C<IO::AIO::SYNC_FILE_RANGE_WRITE> and 1258C<IO::AIO::SYNC_FILE_RANGE_WRITE> and
1106C<IO::AIO::SYNC_FILE_RANGE_WAIT_AFTER>: refer to the sync_file_range 1259C<IO::AIO::SYNC_FILE_RANGE_WAIT_AFTER>: refer to the sync_file_range
1107manpage for details. 1260manpage for details.
1108 1261
1109=item aio_pathsync $path, $callback->($status) 1262=item aio_pathsync $pathname, $callback->($status)
1110 1263
1111This request tries to open, fsync and close the given path. This is a 1264This request tries to open, fsync and close the given path. This is a
1112composite request intended to sync directories after directory operations 1265composite request intended to sync directories after directory operations
1113(E.g. rename). This might not work on all operating systems or have any 1266(E.g. rename). This might not work on all operating systems or have any
1114specific effect, but usually it makes sure that directory changes get 1267specific effect, but usually it makes sure that directory changes get
1166 1319
1167This is a rather advanced IO::AIO call, which works best on mmap(2)ed 1320This is a rather advanced IO::AIO call, which works best on mmap(2)ed
1168scalars. 1321scalars.
1169 1322
1170It touches (reads or writes) all memory pages in the specified 1323It touches (reads or writes) all memory pages in the specified
1171range inside the scalar. All caveats and parameters are the same 1324range inside the scalar. All caveats and parameters are the same
1172as for C<aio_msync>, above, except for flags, which must be either 1325as for C<aio_msync>, above, except for flags, which must be either
1173C<0> (which reads all pages and ensures they are instantiated) or 1326C<0> (which reads all pages and ensures they are instantiated) or
1174C<IO::AIO::MT_MODIFY>, which modifies the memory page s(by reading and 1327C<IO::AIO::MT_MODIFY>, which modifies the memory pages (by reading and
1175writing an octet from it, which dirties the page). 1328writing an octet from it, which dirties the page).
1176 1329
1177=item aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status) 1330=item aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status)
1178 1331
1179This is a rather advanced IO::AIO call, which works best on mmap(2)ed 1332This is a rather advanced IO::AIO call, which works best on mmap(2)ed
1210documented under L<MISCELLANEOUS FUNCTIONS>. 1363documented under L<MISCELLANEOUS FUNCTIONS>.
1211 1364
1212Example: asynchronously lock all current and future pages into memory. 1365Example: asynchronously lock all current and future pages into memory.
1213 1366
1214 aio_mlockall IO::AIO::MCL_FUTURE; 1367 aio_mlockall IO::AIO::MCL_FUTURE;
1368
1369=item aio_fiemap $fh, $start, $length, $flags, $count, $cb->(\@extents)
1370
1371Queries the extents of the given file (by calling the Linux C<FIEMAP>
1372ioctl, see L<http://cvs.schmorp.de/IO-AIO/doc/fiemap.txt> for details). If
1373the ioctl is not available on your OS, then this request will fail with
1374C<ENOSYS>.
1375
1376C<$start> is the starting offset to query extents for, C<$length> is the
1377size of the range to query - if it is C<undef>, then the whole file will
1378be queried.
1379
1380C<$flags> is a combination of flags (C<IO::AIO::FIEMAP_FLAG_SYNC> or
1381C<IO::AIO::FIEMAP_FLAG_XATTR> - C<IO::AIO::FIEMAP_FLAGS_COMPAT> is also
1382exported), and is normally C<0> or C<IO::AIO::FIEMAP_FLAG_SYNC> to query
1383the data portion.
1384
1385C<$count> is the maximum number of extent records to return. If it is
1386C<undef>, then IO::AIO queries all extents of the range. As a very special
1387case, if it is C<0>, then the callback receives the number of extents
1388instead of the extents themselves (which is unreliable, see below).
1389
1390If an error occurs, the callback receives no arguments. The special
1391C<errno> value C<IO::AIO::EBADR> is available to test for flag errors.
1392
1393Otherwise, the callback receives an array reference with extent
1394structures. Each extent structure is an array reference itself, with the
1395following members:
1396
1397 [$logical, $physical, $length, $flags]
1398
1399Flags is any combination of the following flag values (typically either C<0>
1400or C<IO::AIO::FIEMAP_EXTENT_LAST> (1)):
1401
1402C<IO::AIO::FIEMAP_EXTENT_LAST>, C<IO::AIO::FIEMAP_EXTENT_UNKNOWN>,
1403C<IO::AIO::FIEMAP_EXTENT_DELALLOC>, C<IO::AIO::FIEMAP_EXTENT_ENCODED>,
1404C<IO::AIO::FIEMAP_EXTENT_DATA_ENCRYPTED>, C<IO::AIO::FIEMAP_EXTENT_NOT_ALIGNED>,
1405C<IO::AIO::FIEMAP_EXTENT_DATA_INLINE>, C<IO::AIO::FIEMAP_EXTENT_DATA_TAIL>,
1406C<IO::AIO::FIEMAP_EXTENT_UNWRITTEN>, C<IO::AIO::FIEMAP_EXTENT_MERGED> or
1407C<IO::AIO::FIEMAP_EXTENT_SHARED>.
1408
1409At the time of this writing (Linux 3.2), this requets is unreliable unless
1410C<$count> is C<undef>, as the kernel has all sorts of bugs preventing
1411it to return all extents of a range for files with large number of
1412extents. The code works around all these issues if C<$count> is undef.
1215 1413
1216=item aio_group $callback->(...) 1414=item aio_group $callback->(...)
1217 1415
1218This is a very special aio request: Instead of doing something, it is a 1416This is a very special aio request: Instead of doing something, it is a
1219container for other aio requests, which is useful if you want to bundle 1417container for other aio requests, which is useful if you want to bundle
1256like sleep and file handle readable/writable, the overhead this creates is 1454like sleep and file handle readable/writable, the overhead this creates is
1257immense (it blocks a thread for a long time) so do not use this function 1455immense (it blocks a thread for a long time) so do not use this function
1258except to put your application under artificial I/O pressure. 1456except to put your application under artificial I/O pressure.
1259 1457
1260=back 1458=back
1459
1460
1461=head2 IO::AIO::WD - multiple working directories
1462
1463Your process only has one current working directory, which is used by all
1464threads. This makes it hard to use relative paths (some other component
1465could call C<chdir> at any time, and it is hard to control when the path
1466will be used by IO::AIO).
1467
1468One solution for this is to always use absolute paths. This usually works,
1469but can be quite slow (the kernel has to walk the whole path on every
1470access), and can also be a hassle to implement.
1471
1472Newer POSIX systems have a number of functions (openat, fdopendir,
1473futimensat and so on) that make it possible to specify working directories
1474per operation.
1475
1476For portability, and because the clowns who "designed", or shall I write,
1477perpetrated this new interface were obviously half-drunk, this abstraction
1478cannot be perfect, though.
1479
1480IO::AIO allows you to convert directory paths into a so-called IO::AIO::WD
1481object. This object stores the canonicalised, absolute version of the
1482path, and on systems that allow it, also a directory file descriptor.
1483
1484Everywhere where a pathname is accepted by IO::AIO (e.g. in C<aio_stat>
1485or C<aio_unlink>), one can specify an array reference with an IO::AIO::WD
1486object and a pathname instead (or the IO::AIO::WD object alone, which
1487gets interpreted as C<[$wd, "."]>). If the pathname is absolute, the
1488IO::AIO::WD object is ignored, otherwise the pathname is resolved relative
1489to that IO::AIO::WD object.
1490
1491For example, to get a wd object for F</etc> and then stat F<passwd>
1492inside, you would write:
1493
1494 aio_wd "/etc", sub {
1495 my $etcdir = shift;
1496
1497 # although $etcdir can be undef on error, there is generally no reason
1498 # to check for errors here, as aio_stat will fail with ENOENT
1499 # when $etcdir is undef.
1500
1501 aio_stat [$etcdir, "passwd"], sub {
1502 # yay
1503 };
1504 };
1505
1506That C<aio_wd> is a request and not a normal function shows that creating
1507an IO::AIO::WD object is itself a potentially blocking operation, which is
1508why it is done asynchronously.
1509
1510To stat the directory obtained with C<aio_wd> above, one could write
1511either of the following three request calls:
1512
1513 aio_lstat "/etc" , sub { ... # pathname as normal string
1514 aio_lstat [$wd, "."], sub { ... # "." relative to $wd (i.e. $wd itself)
1515 aio_lstat $wd , sub { ... # shorthand for the previous
1516
1517As with normal pathnames, IO::AIO keeps a copy of the working directory
1518object and the pathname string, so you could write the following without
1519causing any issues due to C<$path> getting reused:
1520
1521 my $path = [$wd, undef];
1522
1523 for my $name (qw(abc def ghi)) {
1524 $path->[1] = $name;
1525 aio_stat $path, sub {
1526 # ...
1527 };
1528 }
1529
1530There are some caveats: when directories get renamed (or deleted), the
1531pathname string doesn't change, so will point to the new directory (or
1532nowhere at all), while the directory fd, if available on the system,
1533will still point to the original directory. Most functions accepting a
1534pathname will use the directory fd on newer systems, and the string on
1535older systems. Some functions (such as realpath) will always rely on the
1536string form of the pathname.
1537
1538So this functionality is mainly useful to get some protection against
1539C<chdir>, to easily get an absolute path out of a relative path for future
1540reference, and to speed up doing many operations in the same directory
1541(e.g. when stat'ing all files in a directory).
1542
1543The following functions implement this working directory abstraction:
1544
1545=over 4
1546
1547=item aio_wd $pathname, $callback->($wd)
1548
1549Asynchonously canonicalise the given pathname and convert it to an
1550IO::AIO::WD object representing it. If possible and supported on the
1551system, also open a directory fd to speed up pathname resolution relative
1552to this working directory.
1553
1554If something goes wrong, then C<undef> is passwd to the callback instead
1555of a working directory object and C<$!> is set appropriately. Since
1556passing C<undef> as working directory component of a pathname fails the
1557request with C<ENOENT>, there is often no need for error checking in the
1558C<aio_wd> callback, as future requests using the value will fail in the
1559expected way.
1560
1561If this call isn't available because your OS lacks it or it couldn't be
1562detected, it will be emulated by calling C<fsync> instead.
1563
1564=item IO::AIO::CWD
1565
1566This is a compiletime constant (object) that represents the process
1567current working directory.
1568
1569Specifying this object as working directory object for a pathname is as if
1570the pathname would be specified directly, without a directory object. For
1571example, these calls are functionally identical:
1572
1573 aio_stat "somefile", sub { ... };
1574 aio_stat [IO::AIO::CWD, "somefile"], sub { ... };
1575
1576=back
1577
1578To recover the path associated with an IO::AIO::WD object, you can use
1579C<aio_realpath>:
1580
1581 aio_realpath $wd, sub {
1582 warn "path is $_[0]\n";
1583 };
1584
1585Currently, C<aio_statvfs> always, and C<aio_rename> and C<aio_rmdir>
1586sometimes, fall back to using an absolue path.
1261 1587
1262=head2 IO::AIO::REQ CLASS 1588=head2 IO::AIO::REQ CLASS
1263 1589
1264All non-aggregate C<aio_*> functions return an object of this class when 1590All non-aggregate C<aio_*> functions return an object of this class when
1265called in non-void context. 1591called in non-void context.
1383 1709
1384Sets a feeder/generator on this group: every group can have an attached 1710Sets a feeder/generator on this group: every group can have an attached
1385generator that generates requests if idle. The idea behind this is that, 1711generator that generates requests if idle. The idea behind this is that,
1386although you could just queue as many requests as you want in a group, 1712although you could just queue as many requests as you want in a group,
1387this might starve other requests for a potentially long time. For example, 1713this might starve other requests for a potentially long time. For example,
1388C<aio_scandir> might generate hundreds of thousands C<aio_stat> requests, 1714C<aio_scandir> might generate hundreds of thousands of C<aio_stat>
1389delaying any later requests for a long time. 1715requests, delaying any later requests for a long time.
1390 1716
1391To avoid this, and allow incremental generation of requests, you can 1717To avoid this, and allow incremental generation of requests, you can
1392instead a group and set a feeder on it that generates those requests. The 1718instead a group and set a feeder on it that generates those requests. The
1393feed callback will be called whenever there are few enough (see C<limit>, 1719feed callback will be called whenever there are few enough (see C<limit>,
1394below) requests active in the group itself and is expected to queue more 1720below) requests active in the group itself and is expected to queue more
1443 1769
1444See C<poll_cb> for an example. 1770See C<poll_cb> for an example.
1445 1771
1446=item IO::AIO::poll_cb 1772=item IO::AIO::poll_cb
1447 1773
1448Process some outstanding events on the result pipe. You have to call 1774Process some requests that have reached the result phase (i.e. they have
1775been executed but the results are not yet reported). You have to call
1776this "regularly" to finish outstanding requests.
1777
1449this regularly. Returns C<0> if all events could be processed (or there 1778Returns C<0> if all events could be processed (or there were no
1450were no events to process), or C<-1> if it returned earlier for whatever 1779events to process), or C<-1> if it returned earlier for whatever
1451reason. Returns immediately when no events are outstanding. The amount of 1780reason. Returns immediately when no events are outstanding. The amount
1452events processed depends on the settings of C<IO::AIO::max_poll_req> and 1781of events processed depends on the settings of C<IO::AIO::max_poll_req>,
1453C<IO::AIO::max_poll_time>. 1782C<IO::AIO::max_poll_time> and C<IO::AIO::max_outstanding>.
1454 1783
1455If not all requests were processed for whatever reason, the filehandle 1784If not all requests were processed for whatever reason, the poll file
1456will still be ready when C<poll_cb> returns, so normally you don't have to 1785descriptor will still be ready when C<poll_cb> returns, so normally you
1457do anything special to have it called later. 1786don't have to do anything special to have it called later.
1458 1787
1459Apart from calling C<IO::AIO::poll_cb> when the event filehandle becomes 1788Apart from calling C<IO::AIO::poll_cb> when the event filehandle becomes
1460ready, it can be beneficial to call this function from loops which submit 1789ready, it can be beneficial to call this function from loops which submit
1461a lot of requests, to make sure the results get processed when they become 1790a lot of requests, to make sure the results get processed when they become
1462available and not just when the loop is finished and the event loop takes 1791available and not just when the loop is finished and the event loop takes
1471 poll => 'r', async => 1, 1800 poll => 'r', async => 1,
1472 cb => \&IO::AIO::poll_cb); 1801 cb => \&IO::AIO::poll_cb);
1473 1802
1474=item IO::AIO::poll_wait 1803=item IO::AIO::poll_wait
1475 1804
1476If there are any outstanding requests and none of them in the result 1805Wait until either at least one request is in the result phase or no
1477phase, wait till the result filehandle becomes ready for reading (simply 1806requests are outstanding anymore.
1478does a C<select> on the filehandle. This is useful if you want to 1807
1479synchronously wait for some requests to finish). 1808This is useful if you want to synchronously wait for some requests to
1809become ready, without actually handling them.
1480 1810
1481See C<nreqs> for an example. 1811See C<nreqs> for an example.
1482 1812
1483=item IO::AIO::poll 1813=item IO::AIO::poll
1484 1814
1673 2003
1674=item IO::AIO::fadvise $fh, $offset, $len, $advice 2004=item IO::AIO::fadvise $fh, $offset, $len, $advice
1675 2005
1676Simply calls the C<posix_fadvise> function (see its 2006Simply calls the C<posix_fadvise> function (see its
1677manpage for details). The following advice constants are 2007manpage for details). The following advice constants are
1678avaiable: C<IO::AIO::FADV_NORMAL>, C<IO::AIO::FADV_SEQUENTIAL>, 2008available: C<IO::AIO::FADV_NORMAL>, C<IO::AIO::FADV_SEQUENTIAL>,
1679C<IO::AIO::FADV_RANDOM>, C<IO::AIO::FADV_NOREUSE>, 2009C<IO::AIO::FADV_RANDOM>, C<IO::AIO::FADV_NOREUSE>,
1680C<IO::AIO::FADV_WILLNEED>, C<IO::AIO::FADV_DONTNEED>. 2010C<IO::AIO::FADV_WILLNEED>, C<IO::AIO::FADV_DONTNEED>.
1681 2011
1682On systems that do not implement C<posix_fadvise>, this function returns 2012On systems that do not implement C<posix_fadvise>, this function returns
1683ENOSYS, otherwise the return value of C<posix_fadvise>. 2013ENOSYS, otherwise the return value of C<posix_fadvise>.
1684 2014
1685=item IO::AIO::madvise $scalar, $offset, $len, $advice 2015=item IO::AIO::madvise $scalar, $offset, $len, $advice
1686 2016
1687Simply calls the C<posix_madvise> function (see its 2017Simply calls the C<posix_madvise> function (see its
1688manpage for details). The following advice constants are 2018manpage for details). The following advice constants are
1689avaiable: C<IO::AIO::MADV_NORMAL>, C<IO::AIO::MADV_SEQUENTIAL>, 2019available: C<IO::AIO::MADV_NORMAL>, C<IO::AIO::MADV_SEQUENTIAL>,
1690C<IO::AIO::MADV_RANDOM>, C<IO::AIO::MADV_WILLNEED>, C<IO::AIO::MADV_DONTNEED>. 2020C<IO::AIO::MADV_RANDOM>, C<IO::AIO::MADV_WILLNEED>, C<IO::AIO::MADV_DONTNEED>.
1691 2021
1692On systems that do not implement C<posix_madvise>, this function returns 2022On systems that do not implement C<posix_madvise>, this function returns
1693ENOSYS, otherwise the return value of C<posix_madvise>. 2023ENOSYS, otherwise the return value of C<posix_madvise>.
1694 2024
1695=item IO::AIO::mprotect $scalar, $offset, $len, $protect 2025=item IO::AIO::mprotect $scalar, $offset, $len, $protect
1696 2026
1697Simply calls the C<mprotect> function on the preferably AIO::mmap'ed 2027Simply calls the C<mprotect> function on the preferably AIO::mmap'ed
1698$scalar (see its manpage for details). The following protect 2028$scalar (see its manpage for details). The following protect
1699constants are avaiable: C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_READ>, 2029constants are available: C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_READ>,
1700C<IO::AIO::PROT_WRITE>, C<IO::AIO::PROT_EXEC>. 2030C<IO::AIO::PROT_WRITE>, C<IO::AIO::PROT_EXEC>.
1701 2031
1702On systems that do not implement C<mprotect>, this function returns 2032On systems that do not implement C<mprotect>, this function returns
1703ENOSYS, otherwise the return value of C<mprotect>. 2033ENOSYS, otherwise the return value of C<mprotect>.
1704 2034
1705=item IO::AIO::mmap $scalar, $length, $prot, $flags, $fh[, $offset] 2035=item IO::AIO::mmap $scalar, $length, $prot, $flags, $fh[, $offset]
1706 2036
1707Memory-maps a file (or anonymous memory range) and attaches it to the 2037Memory-maps a file (or anonymous memory range) and attaches it to the
1708given C<$scalar>, which will act like a string scalar. 2038given C<$scalar>, which will act like a string scalar. Returns true on
2039success, and false otherwise.
1709 2040
1710The only operations allowed on the scalar are C<substr>/C<vec> that don't 2041The only operations allowed on the scalar are C<substr>/C<vec> that don't
1711change the string length, and most read-only operations such as copying it 2042change the string length, and most read-only operations such as copying it
1712or searching it with regexes and so on. 2043or searching it with regexes and so on.
1713 2044
1766Calls the C<munlockall> function. 2097Calls the C<munlockall> function.
1767 2098
1768On systems that do not implement C<munlockall>, this function returns 2099On systems that do not implement C<munlockall>, this function returns
1769ENOSYS, otherwise the return value of C<munlockall>. 2100ENOSYS, otherwise the return value of C<munlockall>.
1770 2101
2102=item IO::AIO::splice $r_fh, $r_off, $w_fh, $w_off, $length, $flags
2103
2104Calls the GNU/Linux C<splice(2)> syscall, if available. If C<$r_off> or
2105C<$w_off> are C<undef>, then C<NULL> is passed for these, otherwise they
2106should be the file offset.
2107
2108C<$r_fh> and C<$w_fh> should not refer to the same file, as splice might
2109silently corrupt the data in this case.
2110
2111The following symbol flag values are available: C<IO::AIO::SPLICE_F_MOVE>,
2112C<IO::AIO::SPLICE_F_NONBLOCK>, C<IO::AIO::SPLICE_F_MORE> and
2113C<IO::AIO::SPLICE_F_GIFT>.
2114
2115See the C<splice(2)> manpage for details.
2116
2117=item IO::AIO::tee $r_fh, $w_fh, $length, $flags
2118
2119Calls the GNU/Linux C<tee(2)> syscall, see it's manpage and the
2120description for C<IO::AIO::splice> above for details.
2121
1771=back 2122=back
1772 2123
1773=cut 2124=cut
1774 2125
1775min_parallel 8; 2126min_parallel 8;
1829 2180
1830=over 4 2181=over 4
1831 2182
1832=item IO::AIO::reinit 2183=item IO::AIO::reinit
1833 2184
1834Abondons all current requests and I/O threads and simply reinitialises all 2185Abandons all current requests and I/O threads and simply reinitialises all
1835data structures. This is not an operation suppported by any standards, but 2186data structures. This is not an operation supported by any standards, but
1836happens to work on GNU/Linux and some newer BSD systems. 2187happens to work on GNU/Linux and some newer BSD systems.
1837 2188
1838The only reasonable use for this function is to call it after forking, if 2189The only reasonable use for this function is to call it after forking, if
1839C<IO::AIO> was used in the parent. Calling it while IO::AIO is active in 2190C<IO::AIO> was used in the parent. Calling it while IO::AIO is active in
1840the process will result in undefined behaviour. Calling it at any time 2191the process will result in undefined behaviour. Calling it at any time

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