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Comparing IO-AIO/AIO.pm (file contents):
Revision 1.209 by root, Tue Sep 27 00:41:51 2011 UTC vs.
Revision 1.235 by root, Wed Aug 22 22:28:03 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 = '4.16';
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_fallocate
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
… …
202 202
203=head1 FUNCTIONS 203=head1 FUNCTIONS
204 204
205=head2 QUICK OVERVIEW 205=head2 QUICK OVERVIEW
206 206
207This section simply lists the prototypes of the most important functions 207This section simply lists the prototypes most of the functions for
208for quick reference. See the following sections for function-by-function 208quick reference. See the following sections for function-by-function
209documentation. 209documentation.
210 210
211 aio_wd $pathname, $callback->($wd) 211 aio_wd $pathname, $callback->($wd)
212 aio_open $pathname, $flags, $mode, $callback->($fh) 212 aio_open $pathname, $flags, $mode, $callback->($fh)
213 aio_close $fh, $callback->($status) 213 aio_close $fh, $callback->($status)
214 aio_seek $fh,$offset,$whence, $callback->($offs)
214 aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval) 215 aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
215 aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval) 216 aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
216 aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval) 217 aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval)
217 aio_readahead $fh,$offset,$length, $callback->($retval) 218 aio_readahead $fh,$offset,$length, $callback->($retval)
218 aio_stat $fh_or_path, $callback->($status) 219 aio_stat $fh_or_path, $callback->($status)
219 aio_lstat $fh, $callback->($status) 220 aio_lstat $fh, $callback->($status)
220 aio_statvfs $fh_or_path, $callback->($statvfs) 221 aio_statvfs $fh_or_path, $callback->($statvfs)
221 aio_utime $fh_or_path, $atime, $mtime, $callback->($status) 222 aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
222 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)
223 aio_truncate $fh_or_path, $offset, $callback->($status) 225 aio_truncate $fh_or_path, $offset, $callback->($status)
224 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)
225 aio_unlink $pathname, $callback->($status) 228 aio_unlink $pathname, $callback->($status)
226 aio_mknod $pathname, $mode, $dev, $callback->($status) 229 aio_mknod $pathname, $mode, $dev, $callback->($status)
227 aio_link $srcpath, $dstpath, $callback->($status) 230 aio_link $srcpath, $dstpath, $callback->($status)
228 aio_symlink $srcpath, $dstpath, $callback->($status) 231 aio_symlink $srcpath, $dstpath, $callback->($status)
229 aio_readlink $pathname, $callback->($link) 232 aio_readlink $pathname, $callback->($link)
… …
233 aio_rmdir $pathname, $callback->($status) 236 aio_rmdir $pathname, $callback->($status)
234 aio_readdir $pathname, $callback->($entries) 237 aio_readdir $pathname, $callback->($entries)
235 aio_readdirx $pathname, $flags, $callback->($entries, $flags) 238 aio_readdirx $pathname, $flags, $callback->($entries, $flags)
236 IO::AIO::READDIR_DENTS IO::AIO::READDIR_DIRS_FIRST 239 IO::AIO::READDIR_DENTS IO::AIO::READDIR_DIRS_FIRST
237 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)
238 aio_load $pathname, $data, $callback->($status) 242 aio_load $pathname, $data, $callback->($status)
239 aio_copy $srcpath, $dstpath, $callback->($status) 243 aio_copy $srcpath, $dstpath, $callback->($status)
240 aio_move $srcpath, $dstpath, $callback->($status) 244 aio_move $srcpath, $dstpath, $callback->($status)
241 aio_scandir $pathname, $maxreq, $callback->($dirs, $nondirs)
242 aio_rmtree $pathname, $callback->($status) 245 aio_rmtree $pathname, $callback->($status)
243 aio_sync $callback->($status) 246 aio_sync $callback->($status)
244 aio_syncfs $fh, $callback->($status) 247 aio_syncfs $fh, $callback->($status)
245 aio_fsync $fh, $callback->($status) 248 aio_fsync $fh, $callback->($status)
246 aio_fdatasync $fh, $callback->($status) 249 aio_fdatasync $fh, $callback->($status)
… …
271 IO::AIO::nready 274 IO::AIO::nready
272 IO::AIO::npending 275 IO::AIO::npending
273 276
274 IO::AIO::sendfile $ofh, $ifh, $offset, $count 277 IO::AIO::sendfile $ofh, $ifh, $offset, $count
275 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
276 IO::AIO::madvise $scalar, $offset, $length, $advice 281 IO::AIO::madvise $scalar, $offset, $length, $advice
277 IO::AIO::mprotect $scalar, $offset, $length, $protect 282 IO::AIO::mprotect $scalar, $offset, $length, $protect
278 IO::AIO::munlock $scalar, $offset = 0, $length = undef 283 IO::AIO::munlock $scalar, $offset = 0, $length = undef
279 IO::AIO::munlockall 284 IO::AIO::munlockall
280 285
281=head2 AIO REQUEST FUNCTIONS 286=head2 API NOTES
282 287
283All the C<aio_*> calls are more or less thin wrappers around the syscall 288All the C<aio_*> calls are more or less thin wrappers around the syscall
284with the same name (sans C<aio_>). The arguments are similar or identical, 289with the same name (sans C<aio_>). The arguments are similar or identical,
285and they all accept an additional (and optional) C<$callback> argument 290and they all accept an additional (and optional) C<$callback> argument
286which must be a code reference. This code reference will get called with 291which must be a code reference. This code reference will be called after
287the syscall return code (e.g. most syscalls return C<-1> on error, unlike 292the syscall has been executed in an asynchronous fashion. The results
288perl, which usually delivers "false") as its sole argument after the given 293of the request will be passed as arguments to the callback (and, if an
289syscall has been executed asynchronously. 294error occured, in C<$!>) - 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>.
290 300
291All functions expecting a filehandle keep a copy of the filehandle 301All functions expecting a filehandle keep a copy of the filehandle
292internally until the request has finished. 302internally until the request has finished.
293 303
294All 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
295further manipulation of those requests while they are in-flight. 305further manipulation of those requests while they are in-flight.
296 306
297The pathnames you pass to these routines I<should> be absolute. The 307The pathnames you pass to these routines I<should> be absolute. The
298reason for this is that at the time the request is being executed, the 308reason for this is that at the time the request is being executed, the
299current working directory could have changed. Alternatively, you can make 309current working directory could have changed. Alternatively, you can
300sure that you never change the current working directory anywhere in 310make sure that you never change the current working directory anywhere
301the program and then use relative paths. Lastly, you can take advantage 311in the program and then use relative paths. You can also take advantage
302of IO::AIOs working directory abstraction - see the description of the 312of IO::AIOs working directory abstraction, that lets you specify paths
313relative to some previously-opened "working directory object" - see the
303C<IO::AIO::WD> class later in this document. 314description of the C<IO::AIO::WD> class later in this document.
304 315
305To 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
306in filenames you got from outside (command line, readdir etc.) without 317in filenames you got from outside (command line, readdir etc.) without
307tinkering, 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
308your pathnames to the locale (or other) encoding in effect in the user 319module and encode your pathnames to the locale (or other) encoding in
309environment, d) use Glib::filename_from_unicode on unicode filenames or e) 320effect in the user environment, d) use Glib::filename_from_unicode on
310use 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.
311 323
312This 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
313handles correctly whether it is set or not. 325handles correctly whether it is set or not.
326
327=head2 AIO REQUEST FUNCTIONS
314 328
315=over 4 329=over 4
316 330
317=item $prev_pri = aioreq_pri [$pri] 331=item $prev_pri = aioreq_pri [$pri]
318 332
… …
348 362
349 363
350=item aio_open $pathname, $flags, $mode, $callback->($fh) 364=item aio_open $pathname, $flags, $mode, $callback->($fh)
351 365
352Asynchronously 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
353created filehandle for the file. 367created filehandle for the file (or C<undef> in case of an error).
354 368
355The 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,
356for an explanation. 370for an explanation.
357 371
358The 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
… …
400 414
401Or 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
402free for reuse until the perl filehandle is closed. 416free for reuse until the perl filehandle is closed.
403 417
404=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".
405 439
406=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval) 440=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
407 441
408=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval) 442=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
409 443
… …
569 namemax => 255, 603 namemax => 255,
570 frsize => 1024, 604 frsize => 1024,
571 fsid => 1810 605 fsid => 1810
572 } 606 }
573 607
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
574 689
575=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status) 690=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
576 691
577Works 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
578and $mtime being undef). Fractional times are supported if the underlying 693and $mtime being undef). Fractional times are supported if the underlying
… …
604 719
605 720
606=item aio_truncate $fh_or_path, $offset, $callback->($status) 721=item aio_truncate $fh_or_path, $offset, $callback->($status)
607 722
608Works like truncate(2) or ftruncate(2). 723Works like truncate(2) or ftruncate(2).
724
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>.
609 740
610 741
611=item aio_chmod $fh_or_path, $mode, $callback->($status) 742=item aio_chmod $fh_or_path, $mode, $callback->($status)
612 743
613Works like perl's C<chmod> function. 744Works like perl's C<chmod> function.
… …
966 1097
967 my $grp = aio_group $cb; 1098 my $grp = aio_group $cb;
968 1099
969 $maxreq = 4 if $maxreq <= 0; 1100 $maxreq = 4 if $maxreq <= 0;
970 1101
971 # stat once 1102 # get a wd object
972 aioreq_pri $pri; 1103 aioreq_pri $pri;
973 add $grp aio_stat $path, sub { 1104 add $grp aio_wd $path, sub {
1105 $_[0]
974 return $grp->result () if $_[0]; 1106 or return $grp->result ();
975 my $now = time;
976 my $hash1 = join ":", (stat _)[0,1,3,7,9];
977 1107
978 # read the directory entries 1108 my $wd = [shift, "."];
1109
1110 # stat once
979 aioreq_pri $pri; 1111 aioreq_pri $pri;
980 add $grp aio_readdirx $path, READDIR_DIRS_FIRST, sub { 1112 add $grp aio_stat $wd, sub {
981 my $entries = shift
982 or return $grp->result (); 1113 return $grp->result () if $_[0];
1114 my $now = time;
1115 my $hash1 = join ":", (stat _)[0,1,3,7,9];
983 1116
984 # stat the dir another time 1117 # read the directory entries
985 aioreq_pri $pri; 1118 aioreq_pri $pri;
1119 add $grp aio_readdirx $wd, READDIR_DIRS_FIRST, sub {
1120 my $entries = shift
1121 or return $grp->result ();
1122
1123 # stat the dir another time
1124 aioreq_pri $pri;
986 add $grp aio_stat $path, sub { 1125 add $grp aio_stat $wd, sub {
987 my $hash2 = join ":", (stat _)[0,1,3,7,9]; 1126 my $hash2 = join ":", (stat _)[0,1,3,7,9];
988 1127
989 my $ndirs; 1128 my $ndirs;
990 1129
991 # take the slow route if anything looks fishy 1130 # take the slow route if anything looks fishy
992 if ($hash1 ne $hash2 or (stat _)[9] == $now) { 1131 if ($hash1 ne $hash2 or (stat _)[9] == $now) {
993 $ndirs = -1; 1132 $ndirs = -1;
994 } else { 1133 } else {
995 # if nlink == 2, we are finished 1134 # if nlink == 2, we are finished
996 # for non-posix-fs's, we rely on nlink < 2 1135 # for non-posix-fs's, we rely on nlink < 2
997 $ndirs = (stat _)[3] - 2 1136 $ndirs = (stat _)[3] - 2
998 or return $grp->result ([], $entries); 1137 or return $grp->result ([], $entries);
999 } 1138 }
1000 1139
1001 my (@dirs, @nondirs); 1140 my (@dirs, @nondirs);
1002 1141
1003 my $statgrp = add $grp aio_group sub { 1142 my $statgrp = add $grp aio_group sub {
1004 $grp->result (\@dirs, \@nondirs); 1143 $grp->result (\@dirs, \@nondirs);
1005 }; 1144 };
1006 1145
1007 limit $statgrp $maxreq; 1146 limit $statgrp $maxreq;
1008 feed $statgrp sub { 1147 feed $statgrp sub {
1009 return unless @$entries; 1148 return unless @$entries;
1010 my $entry = shift @$entries; 1149 my $entry = shift @$entries;
1011 1150
1012 aioreq_pri $pri; 1151 aioreq_pri $pri;
1152 $wd->[1] = "$entry/.";
1013 add $statgrp aio_stat "$path/$entry/.", sub { 1153 add $statgrp aio_stat $wd, sub {
1014 if ($_[0] < 0) { 1154 if ($_[0] < 0) {
1015 push @nondirs, $entry; 1155 push @nondirs, $entry;
1016 } else { 1156 } else {
1017 # need to check for real directory 1157 # need to check for real directory
1018 aioreq_pri $pri; 1158 aioreq_pri $pri;
1159 $wd->[1] = $entry;
1019 add $statgrp aio_lstat "$path/$entry", sub { 1160 add $statgrp aio_lstat $wd, sub {
1020 if (-d _) { 1161 if (-d _) {
1021 push @dirs, $entry; 1162 push @dirs, $entry;
1022 1163
1023 unless (--$ndirs) { 1164 unless (--$ndirs) {
1024 push @nondirs, @$entries; 1165 push @nondirs, @$entries;
1025 feed $statgrp; 1166 feed $statgrp;
1167 }
1168 } else {
1169 push @nondirs, $entry;
1026 } 1170 }
1027 } else {
1028 push @nondirs, $entry;
1029 } 1171 }
1030 } 1172 }
1031 } 1173 };
1032 }; 1174 };
1033 }; 1175 };
1034 }; 1176 };
1035 }; 1177 };
1036 }; 1178 };
… …
1214 1356
1215Example: asynchronously lock all current and future pages into memory. 1357Example: asynchronously lock all current and future pages into memory.
1216 1358
1217 aio_mlockall IO::AIO::MCL_FUTURE; 1359 aio_mlockall IO::AIO::MCL_FUTURE;
1218 1360
1361=item aio_fiemap $fh, $start, $length, $flags, $count, $cb->(\@extents)
1362
1363Queries the extents of the given file (by calling the Linux C<FIEMAP>
1364ioctl, see L<http://cvs.schmorp.de/IO-AIO/doc/fiemap.txt> for details). If
1365the ioctl is not available on your OS, then this request will fail with
1366C<ENOSYS>.
1367
1368C<$start> is the starting offset to query extents for, C<$length> is the
1369size of the range to query - if it is C<undef>, then the whole file will
1370be queried.
1371
1372C<$flags> is a combination of flags (C<IO::AIO::FIEMAP_FLAG_SYNC> or
1373C<IO::AIO::FIEMAP_FLAG_XATTR> - C<IO::AIO::FIEMAP_FLAGS_COMPAT> is also
1374exported), and is normally C<0> or C<IO::AIO::FIEMAP_FLAG_SYNC> to query
1375the data portion.
1376
1377C<$count> is the maximum number of extent records to return. If it is
1378C<undef>, then IO::AIO queries all extents of the range. As a very special
1379case, if it is C<0>, then the callback receives the number of extents
1380instead of the extents themselves (which is unreliable, see below).
1381
1382If an error occurs, the callback receives no arguments. The special
1383C<errno> value C<IO::AIO::EBADR> is available to test for flag errors.
1384
1385Otherwise, the callback receives an array reference with extent
1386structures. Each extent structure is an array reference itself, with the
1387following members:
1388
1389 [$logical, $physical, $length, $flags]
1390
1391Flags is any combination of the following flag values (typically either C<0>
1392or C<IO::AIO::FIEMAP_EXTENT_LAST> (1)):
1393
1394C<IO::AIO::FIEMAP_EXTENT_LAST>, C<IO::AIO::FIEMAP_EXTENT_UNKNOWN>,
1395C<IO::AIO::FIEMAP_EXTENT_DELALLOC>, C<IO::AIO::FIEMAP_EXTENT_ENCODED>,
1396C<IO::AIO::FIEMAP_EXTENT_DATA_ENCRYPTED>, C<IO::AIO::FIEMAP_EXTENT_NOT_ALIGNED>,
1397C<IO::AIO::FIEMAP_EXTENT_DATA_INLINE>, C<IO::AIO::FIEMAP_EXTENT_DATA_TAIL>,
1398C<IO::AIO::FIEMAP_EXTENT_UNWRITTEN>, C<IO::AIO::FIEMAP_EXTENT_MERGED> or
1399C<IO::AIO::FIEMAP_EXTENT_SHARED>.
1400
1401At the time of this writing (Linux 3.2), this requets is unreliable unless
1402C<$count> is C<undef>, as the kernel has all sorts of bugs preventing
1403it to return all extents of a range for files with large number of
1404extents. The code works around all these issues if C<$count> is undef.
1405
1219=item aio_group $callback->(...) 1406=item aio_group $callback->(...)
1220 1407
1221This is a very special aio request: Instead of doing something, it is a 1408This is a very special aio request: Instead of doing something, it is a
1222container for other aio requests, which is useful if you want to bundle 1409container for other aio requests, which is useful if you want to bundle
1223many requests into a single, composite, request with a definite callback 1410many requests into a single, composite, request with a definite callback
… …
1286object. This object stores the canonicalised, absolute version of the 1473object. This object stores the canonicalised, absolute version of the
1287path, and on systems that allow it, also a directory file descriptor. 1474path, and on systems that allow it, also a directory file descriptor.
1288 1475
1289Everywhere where a pathname is accepted by IO::AIO (e.g. in C<aio_stat> 1476Everywhere where a pathname is accepted by IO::AIO (e.g. in C<aio_stat>
1290or C<aio_unlink>), one can specify an array reference with an IO::AIO::WD 1477or C<aio_unlink>), one can specify an array reference with an IO::AIO::WD
1291object and a pathname instead. If the pathname is absolute, the 1478object and a pathname instead (or the IO::AIO::WD object alone, which
1479gets interpreted as C<[$wd, "."]>). If the pathname is absolute, the
1292IO::AIO::WD objetc is ignored, otherwise the pathname is resolved relative 1480IO::AIO::WD object is ignored, otherwise the pathname is resolved relative
1293to that IO::AIO::WD object. 1481to that IO::AIO::WD object.
1294 1482
1295For example, to get a wd object for F</etc> and then stat F<passwd> 1483For example, to get a wd object for F</etc> and then stat F<passwd>
1296inside, you would write: 1484inside, you would write:
1297 1485
… …
1305 aio_stat [$etcdir, "passwd"], sub { 1493 aio_stat [$etcdir, "passwd"], sub {
1306 # yay 1494 # yay
1307 }; 1495 };
1308 }; 1496 };
1309 1497
1310This shows that creating an IO::AIO::WD object is itself a potentially 1498That C<aio_wd> is a request and not a normal function shows that creating
1311blocking operation, which is why it is done asynchronously. 1499an IO::AIO::WD object is itself a potentially blocking operation, which is
1500why it is done asynchronously.
1501
1502To stat the directory obtained with C<aio_wd> above, one could write
1503either of the following three request calls:
1504
1505 aio_lstat "/etc" , sub { ... # pathname as normal string
1506 aio_lstat [$wd, "."], sub { ... # "." relative to $wd (i.e. $wd itself)
1507 aio_lstat $wd , sub { ... # shorthand for the previous
1312 1508
1313As with normal pathnames, IO::AIO keeps a copy of the working directory 1509As with normal pathnames, IO::AIO keeps a copy of the working directory
1314object and the pathname string, so you could write the following without 1510object and the pathname string, so you could write the following without
1315causing any issues due to C<$path> getting reused: 1511causing any issues due to C<$path> getting reused:
1316 1512
… …
1496 1692
1497Sets a feeder/generator on this group: every group can have an attached 1693Sets a feeder/generator on this group: every group can have an attached
1498generator that generates requests if idle. The idea behind this is that, 1694generator that generates requests if idle. The idea behind this is that,
1499although you could just queue as many requests as you want in a group, 1695although you could just queue as many requests as you want in a group,
1500this might starve other requests for a potentially long time. For example, 1696this might starve other requests for a potentially long time. For example,
1501C<aio_scandir> might generate hundreds of thousands C<aio_stat> requests, 1697C<aio_scandir> might generate hundreds of thousands of C<aio_stat>
1502delaying any later requests for a long time. 1698requests, delaying any later requests for a long time.
1503 1699
1504To avoid this, and allow incremental generation of requests, you can 1700To avoid this, and allow incremental generation of requests, you can
1505instead a group and set a feeder on it that generates those requests. The 1701instead a group and set a feeder on it that generates those requests. The
1506feed callback will be called whenever there are few enough (see C<limit>, 1702feed callback will be called whenever there are few enough (see C<limit>,
1507below) requests active in the group itself and is expected to queue more 1703below) requests active in the group itself and is expected to queue more
… …
1816ENOSYS, otherwise the return value of C<mprotect>. 2012ENOSYS, otherwise the return value of C<mprotect>.
1817 2013
1818=item IO::AIO::mmap $scalar, $length, $prot, $flags, $fh[, $offset] 2014=item IO::AIO::mmap $scalar, $length, $prot, $flags, $fh[, $offset]
1819 2015
1820Memory-maps a file (or anonymous memory range) and attaches it to the 2016Memory-maps a file (or anonymous memory range) and attaches it to the
1821given C<$scalar>, which will act like a string scalar. 2017given C<$scalar>, which will act like a string scalar. Returns true on
2018success, and false otherwise.
1822 2019
1823The only operations allowed on the scalar are C<substr>/C<vec> that don't 2020The only operations allowed on the scalar are C<substr>/C<vec> that don't
1824change the string length, and most read-only operations such as copying it 2021change the string length, and most read-only operations such as copying it
1825or searching it with regexes and so on. 2022or searching it with regexes and so on.
1826 2023
… …
1879Calls the C<munlockall> function. 2076Calls the C<munlockall> function.
1880 2077
1881On systems that do not implement C<munlockall>, this function returns 2078On systems that do not implement C<munlockall>, this function returns
1882ENOSYS, otherwise the return value of C<munlockall>. 2079ENOSYS, otherwise the return value of C<munlockall>.
1883 2080
2081=item IO::AIO::splice $r_fh, $r_off, $w_fh, $w_off, $length, $flags
2082
2083Calls the GNU/Linux C<splice(2)> syscall, if available. If C<$r_off> or
2084C<$w_off> are C<undef>, then C<NULL> is passed for these, otherwise they
2085should be the file offset.
2086
2087C<$r_fh> and C<$w_fh> should not refer to the same file, as splice might
2088silently corrupt the data in this case.
2089
2090The following symbol flag values are available: C<IO::AIO::SPLICE_F_MOVE>,
2091C<IO::AIO::SPLICE_F_NONBLOCK>, C<IO::AIO::SPLICE_F_MORE> and
2092C<IO::AIO::SPLICE_F_GIFT>.
2093
2094See the C<splice(2)> manpage for details.
2095
2096=item IO::AIO::tee $r_fh, $w_fh, $length, $flags
2097
2098Calls the GNU/Linux C<tee(2)> syscall, see it's manpage and the
2099description for C<IO::AIO::splice> above for details.
2100
1884=back 2101=back
1885 2102
1886=cut 2103=cut
1887 2104
1888min_parallel 8; 2105min_parallel 8;

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