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Revision 1.208 by root, Mon Sep 26 20:19:08 2011 UTC vs.
Revision 1.244 by root, Fri Jan 24 23:46:16 2014 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;
168use common::sense; 167use common::sense;
169 168
170use base 'Exporter'; 169use base 'Exporter';
171 170
172BEGIN { 171BEGIN {
173 our $VERSION = '4.0'; 172 our $VERSION = '4.19';
174 173
175 our @AIO_REQ = qw(aio_sendfile aio_read aio_write aio_open aio_close 174 our @AIO_REQ = qw(aio_sendfile aio_seek aio_read aio_write aio_open aio_close
176 aio_stat aio_lstat aio_unlink aio_rmdir aio_readdir aio_readdirx 175 aio_stat aio_lstat aio_unlink aio_rmdir aio_readdir aio_readdirx
177 aio_scandir aio_symlink aio_readlink aio_realpath aio_sync 176 aio_scandir aio_symlink aio_readlink aio_realpath aio_sync
178 aio_fsync aio_syncfs aio_fdatasync aio_sync_file_range aio_fallocate 177 aio_fsync aio_syncfs aio_fdatasync aio_sync_file_range aio_allocate
179 aio_pathsync aio_readahead 178 aio_pathsync aio_readahead aio_fiemap
180 aio_rename aio_link aio_move aio_copy aio_group 179 aio_rename aio_link aio_move aio_copy aio_group
181 aio_nop aio_mknod aio_load aio_rmtree aio_mkdir aio_chown 180 aio_nop aio_mknod aio_load aio_rmtree aio_mkdir aio_chown
182 aio_chmod aio_utime aio_truncate 181 aio_chmod aio_utime aio_truncate
183 aio_msync aio_mtouch aio_mlock aio_mlockall 182 aio_msync aio_mtouch aio_mlock aio_mlockall
184 aio_statvfs 183 aio_statvfs
202 201
203=head1 FUNCTIONS 202=head1 FUNCTIONS
204 203
205=head2 QUICK OVERVIEW 204=head2 QUICK OVERVIEW
206 205
207This section simply lists the prototypes of the most important functions 206This section simply lists the prototypes most of the functions for
208for quick reference. See the following sections for function-by-function 207quick reference. See the following sections for function-by-function
209documentation. 208documentation.
210 209
211 aio_wd $pathname, $callback->($wd) 210 aio_wd $pathname, $callback->($wd)
212 aio_open $pathname, $flags, $mode, $callback->($fh) 211 aio_open $pathname, $flags, $mode, $callback->($fh)
213 aio_close $fh, $callback->($status) 212 aio_close $fh, $callback->($status)
213 aio_seek $fh,$offset,$whence, $callback->($offs)
214 aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval) 214 aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
215 aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval) 215 aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
216 aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval) 216 aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval)
217 aio_readahead $fh,$offset,$length, $callback->($retval) 217 aio_readahead $fh,$offset,$length, $callback->($retval)
218 aio_stat $fh_or_path, $callback->($status) 218 aio_stat $fh_or_path, $callback->($status)
219 aio_lstat $fh, $callback->($status) 219 aio_lstat $fh, $callback->($status)
220 aio_statvfs $fh_or_path, $callback->($statvfs) 220 aio_statvfs $fh_or_path, $callback->($statvfs)
221 aio_utime $fh_or_path, $atime, $mtime, $callback->($status) 221 aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
222 aio_chown $fh_or_path, $uid, $gid, $callback->($status) 222 aio_chown $fh_or_path, $uid, $gid, $callback->($status)
223 aio_chmod $fh_or_path, $mode, $callback->($status)
223 aio_truncate $fh_or_path, $offset, $callback->($status) 224 aio_truncate $fh_or_path, $offset, $callback->($status)
224 aio_chmod $fh_or_path, $mode, $callback->($status) 225 aio_allocate $fh, $mode, $offset, $len, $callback->($status)
226 aio_fiemap $fh, $start, $length, $flags, $count, $cb->(\@extents)
225 aio_unlink $pathname, $callback->($status) 227 aio_unlink $pathname, $callback->($status)
226 aio_mknod $path, $mode, $dev, $callback->($status) 228 aio_mknod $pathname, $mode, $dev, $callback->($status)
227 aio_link $srcpath, $dstpath, $callback->($status) 229 aio_link $srcpath, $dstpath, $callback->($status)
228 aio_symlink $srcpath, $dstpath, $callback->($status) 230 aio_symlink $srcpath, $dstpath, $callback->($status)
229 aio_readlink $path, $callback->($link) 231 aio_readlink $pathname, $callback->($link)
230 aio_realpath $path, $callback->($link) 232 aio_realpath $pathname, $callback->($link)
231 aio_rename $srcpath, $dstpath, $callback->($status) 233 aio_rename $srcpath, $dstpath, $callback->($status)
232 aio_mkdir $pathname, $mode, $callback->($status) 234 aio_mkdir $pathname, $mode, $callback->($status)
233 aio_rmdir $pathname, $callback->($status) 235 aio_rmdir $pathname, $callback->($status)
234 aio_readdir $pathname, $callback->($entries) 236 aio_readdir $pathname, $callback->($entries)
235 aio_readdirx $pathname, $flags, $callback->($entries, $flags) 237 aio_readdirx $pathname, $flags, $callback->($entries, $flags)
236 IO::AIO::READDIR_DENTS IO::AIO::READDIR_DIRS_FIRST 238 IO::AIO::READDIR_DENTS IO::AIO::READDIR_DIRS_FIRST
237 IO::AIO::READDIR_STAT_ORDER IO::AIO::READDIR_FOUND_UNKNOWN 239 IO::AIO::READDIR_STAT_ORDER IO::AIO::READDIR_FOUND_UNKNOWN
240 aio_scandir $pathname, $maxreq, $callback->($dirs, $nondirs)
238 aio_load $path, $data, $callback->($status) 241 aio_load $pathname, $data, $callback->($status)
239 aio_copy $srcpath, $dstpath, $callback->($status) 242 aio_copy $srcpath, $dstpath, $callback->($status)
240 aio_move $srcpath, $dstpath, $callback->($status) 243 aio_move $srcpath, $dstpath, $callback->($status)
241 aio_scandir $path, $maxreq, $callback->($dirs, $nondirs)
242 aio_rmtree $path, $callback->($status) 244 aio_rmtree $pathname, $callback->($status)
243 aio_sync $callback->($status) 245 aio_sync $callback->($status)
244 aio_syncfs $fh, $callback->($status) 246 aio_syncfs $fh, $callback->($status)
245 aio_fsync $fh, $callback->($status) 247 aio_fsync $fh, $callback->($status)
246 aio_fdatasync $fh, $callback->($status) 248 aio_fdatasync $fh, $callback->($status)
247 aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status) 249 aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status)
248 aio_pathsync $path, $callback->($status) 250 aio_pathsync $pathname, $callback->($status)
249 aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status) 251 aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
250 aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status) 252 aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
251 aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status) 253 aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status)
252 aio_mlockall $flags, $callback->($status) 254 aio_mlockall $flags, $callback->($status)
253 aio_group $callback->(...) 255 aio_group $callback->(...)
271 IO::AIO::nready 273 IO::AIO::nready
272 IO::AIO::npending 274 IO::AIO::npending
273 275
274 IO::AIO::sendfile $ofh, $ifh, $offset, $count 276 IO::AIO::sendfile $ofh, $ifh, $offset, $count
275 IO::AIO::fadvise $fh, $offset, $len, $advice 277 IO::AIO::fadvise $fh, $offset, $len, $advice
278 IO::AIO::mmap $scalar, $length, $prot, $flags[, $fh[, $offset]]
279 IO::AIO::munmap $scalar
276 IO::AIO::madvise $scalar, $offset, $length, $advice 280 IO::AIO::madvise $scalar, $offset, $length, $advice
277 IO::AIO::mprotect $scalar, $offset, $length, $protect 281 IO::AIO::mprotect $scalar, $offset, $length, $protect
278 IO::AIO::munlock $scalar, $offset = 0, $length = undef 282 IO::AIO::munlock $scalar, $offset = 0, $length = undef
279 IO::AIO::munlockall 283 IO::AIO::munlockall
280 284
281=head2 AIO REQUEST FUNCTIONS 285=head2 API NOTES
282 286
283All the C<aio_*> calls are more or less thin wrappers around the syscall 287All the C<aio_*> calls are more or less thin wrappers around the syscall
284with the same name (sans C<aio_>). The arguments are similar or identical, 288with the same name (sans C<aio_>). The arguments are similar or identical,
285and they all accept an additional (and optional) C<$callback> argument 289and they all accept an additional (and optional) C<$callback> argument
286which must be a code reference. This code reference will get called with 290which must be a code reference. This code reference will be called after
287the syscall return code (e.g. most syscalls return C<-1> on error, unlike 291the syscall has been executed in an asynchronous fashion. The results
288perl, which usually delivers "false") as its sole argument after the given 292of the request will be passed as arguments to the callback (and, if an
289syscall has been executed asynchronously. 293error occured, in C<$!>) - for most requests the syscall return code (e.g.
294most syscalls return C<-1> on error, unlike perl, which usually delivers
295"false").
296
297Some requests (such as C<aio_readdir>) pass the actual results and
298communicate failures by passing C<undef>.
290 299
291All functions expecting a filehandle keep a copy of the filehandle 300All functions expecting a filehandle keep a copy of the filehandle
292internally until the request has finished. 301internally until the request has finished.
293 302
294All functions return request objects of type L<IO::AIO::REQ> that allow 303All functions return request objects of type L<IO::AIO::REQ> that allow
295further manipulation of those requests while they are in-flight. 304further manipulation of those requests while they are in-flight.
296 305
297The pathnames you pass to these routines I<must> be absolute and 306The pathnames you pass to these routines I<should> be absolute. The
298encoded as octets. The reason for the former is that at the time the 307reason for this is that at the time the request is being executed, the
299request is being executed, the current working directory could have 308current working directory could have changed. Alternatively, you can
300changed. Alternatively, you can make sure that you never change the 309make sure that you never change the current working directory anywhere
301current working directory anywhere in the program and then use relative 310in the program and then use relative paths. You can also take advantage
302paths. 311of IO::AIOs working directory abstraction, that lets you specify paths
312relative to some previously-opened "working directory object" - see the
313description of the C<IO::AIO::WD> class later in this document.
303 314
304To encode pathnames as octets, either make sure you either: a) always pass 315To encode pathnames as octets, either make sure you either: a) always pass
305in filenames you got from outside (command line, readdir etc.) without 316in filenames you got from outside (command line, readdir etc.) without
306tinkering, b) are ASCII or ISO 8859-1, c) use the Encode module and encode 317tinkering, b) are in your native filesystem encoding, c) use the Encode
307your pathnames to the locale (or other) encoding in effect in the user 318module and encode your pathnames to the locale (or other) encoding in
308environment, d) use Glib::filename_from_unicode on unicode filenames or e) 319effect in the user environment, d) use Glib::filename_from_unicode on
309use something else to ensure your scalar has the correct contents. 320unicode filenames or e) use something else to ensure your scalar has the
321correct contents.
310 322
311This works, btw. independent of the internal UTF-8 bit, which IO::AIO 323This works, btw. independent of the internal UTF-8 bit, which IO::AIO
312handles correctly whether it is set or not. 324handles correctly whether it is set or not.
325
326=head2 AIO REQUEST FUNCTIONS
313 327
314=over 4 328=over 4
315 329
316=item $prev_pri = aioreq_pri [$pri] 330=item $prev_pri = aioreq_pri [$pri]
317 331
347 361
348 362
349=item aio_open $pathname, $flags, $mode, $callback->($fh) 363=item aio_open $pathname, $flags, $mode, $callback->($fh)
350 364
351Asynchronously open or create a file and call the callback with a newly 365Asynchronously open or create a file and call the callback with a newly
352created filehandle for the file. 366created filehandle for the file (or C<undef> in case of an error).
353 367
354The pathname passed to C<aio_open> must be absolute. See API NOTES, above, 368The pathname passed to C<aio_open> must be absolute. See API NOTES, above,
355for an explanation. 369for an explanation.
356 370
357The C<$flags> argument is a bitmask. See the C<Fcntl> module for a 371The C<$flags> argument is a bitmask. See the C<Fcntl> module for a
399 413
400Or in other words: the file descriptor will be closed, but it will not be 414Or in other words: the file descriptor will be closed, but it will not be
401free for reuse until the perl filehandle is closed. 415free for reuse until the perl filehandle is closed.
402 416
403=cut 417=cut
418
419=item aio_seek $fh, $offset, $whence, $callback->($offs)
420
421Seeks the filehandle to the new C<$offset>, similarly to perl's
422C<sysseek>. The C<$whence> can use the traditional values (C<0> for
423C<IO::AIO::SEEK_SET>, C<1> for C<IO::AIO::SEEK_CUR> or C<2> for
424C<IO::AIO::SEEK_END>).
425
426The resulting absolute offset will be passed to the callback, or C<-1> in
427case of an error.
428
429In theory, the C<$whence> constants could be different than the
430corresponding values from L<Fcntl>, but perl guarantees they are the same,
431so don't panic.
432
433As a GNU/Linux (and maybe Solaris) extension, also the constants
434C<IO::AIO::SEEK_DATA> and C<IO::AIO::SEEK_HOLE> are available, if they
435could be found. No guarantees about suitability for use in C<aio_seek> or
436Perl's C<sysseek> can be made though, although I would naively assume they
437"just work".
404 438
405=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval) 439=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
406 440
407=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval) 441=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
408 442
568 namemax => 255, 602 namemax => 255,
569 frsize => 1024, 603 frsize => 1024,
570 fsid => 1810 604 fsid => 1810
571 } 605 }
572 606
607Here is a (likely partial - send me updates!) list of fsid values used by
608Linux - it is safe to hardcode these when C<$^O> is C<linux>:
609
610 0x0000adf5 adfs
611 0x0000adff affs
612 0x5346414f afs
613 0x09041934 anon-inode filesystem
614 0x00000187 autofs
615 0x42465331 befs
616 0x1badface bfs
617 0x42494e4d binfmt_misc
618 0x9123683e btrfs
619 0x0027e0eb cgroupfs
620 0xff534d42 cifs
621 0x73757245 coda
622 0x012ff7b7 coh
623 0x28cd3d45 cramfs
624 0x453dcd28 cramfs-wend (wrong endianness)
625 0x64626720 debugfs
626 0x00001373 devfs
627 0x00001cd1 devpts
628 0x0000f15f ecryptfs
629 0x00414a53 efs
630 0x0000137d ext
631 0x0000ef53 ext2/ext3
632 0x0000ef51 ext2
633 0x00004006 fat
634 0x65735546 fuseblk
635 0x65735543 fusectl
636 0x0bad1dea futexfs
637 0x01161970 gfs2
638 0x47504653 gpfs
639 0x00004244 hfs
640 0xf995e849 hpfs
641 0x958458f6 hugetlbfs
642 0x2bad1dea inotifyfs
643 0x00009660 isofs
644 0x000072b6 jffs2
645 0x3153464a jfs
646 0x6b414653 k-afs
647 0x0bd00bd0 lustre
648 0x0000137f minix
649 0x0000138f minix 30 char names
650 0x00002468 minix v2
651 0x00002478 minix v2 30 char names
652 0x00004d5a minix v3
653 0x19800202 mqueue
654 0x00004d44 msdos
655 0x0000564c novell
656 0x00006969 nfs
657 0x6e667364 nfsd
658 0x00003434 nilfs
659 0x5346544e ntfs
660 0x00009fa1 openprom
661 0x7461636F ocfs2
662 0x00009fa0 proc
663 0x6165676c pstorefs
664 0x0000002f qnx4
665 0x858458f6 ramfs
666 0x52654973 reiserfs
667 0x00007275 romfs
668 0x67596969 rpc_pipefs
669 0x73636673 securityfs
670 0xf97cff8c selinux
671 0x0000517b smb
672 0x534f434b sockfs
673 0x73717368 squashfs
674 0x62656572 sysfs
675 0x012ff7b6 sysv2
676 0x012ff7b5 sysv4
677 0x01021994 tmpfs
678 0x15013346 udf
679 0x00011954 ufs
680 0x54190100 ufs byteswapped
681 0x00009fa2 usbdevfs
682 0x01021997 v9fs
683 0xa501fcf5 vxfs
684 0xabba1974 xenfs
685 0x012ff7b4 xenix
686 0x58465342 xfs
687 0x012fd16d xia
573 688
574=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status) 689=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
575 690
576Works like perl's C<utime> function (including the special case of $atime 691Works like perl's C<utime> function (including the special case of $atime
577and $mtime being undef). Fractional times are supported if the underlying 692and $mtime being undef). Fractional times are supported if the underlying
605=item aio_truncate $fh_or_path, $offset, $callback->($status) 720=item aio_truncate $fh_or_path, $offset, $callback->($status)
606 721
607Works like truncate(2) or ftruncate(2). 722Works like truncate(2) or ftruncate(2).
608 723
609 724
725=item aio_allocate $fh, $mode, $offset, $len, $callback->($status)
726
727Allocates or freed disk space according to the C<$mode> argument. See the
728linux C<fallocate> docuemntation for details.
729
730C<$mode> can currently be C<0> or C<IO::AIO::FALLOC_FL_KEEP_SIZE>
731to allocate space, or C<IO::AIO::FALLOC_FL_PUNCH_HOLE |
732IO::AIO::FALLOC_FL_KEEP_SIZE>, to deallocate a file range.
733
734The file system block size used by C<fallocate> is presumably the
735C<f_bsize> returned by C<statvfs>.
736
737If C<fallocate> isn't available or cannot be emulated (currently no
738emulation will be attempted), passes C<-1> and sets C<$!> to C<ENOSYS>.
739
740
610=item aio_chmod $fh_or_path, $mode, $callback->($status) 741=item aio_chmod $fh_or_path, $mode, $callback->($status)
611 742
612Works like perl's C<chmod> function. 743Works like perl's C<chmod> function.
613 744
614 745
616 747
617Asynchronously unlink (delete) a file and call the callback with the 748Asynchronously unlink (delete) a file and call the callback with the
618result code. 749result code.
619 750
620 751
621=item aio_mknod $path, $mode, $dev, $callback->($status) 752=item aio_mknod $pathname, $mode, $dev, $callback->($status)
622 753
623[EXPERIMENTAL] 754[EXPERIMENTAL]
624 755
625Asynchronously create a device node (or fifo). See mknod(2). 756Asynchronously create a device node (or fifo). See mknod(2).
626 757
627The only (POSIX-) portable way of calling this function is: 758The only (POSIX-) portable way of calling this function is:
628 759
629 aio_mknod $path, IO::AIO::S_IFIFO | $mode, 0, sub { ... 760 aio_mknod $pathname, IO::AIO::S_IFIFO | $mode, 0, sub { ...
630 761
631See C<aio_stat> for info about some potentially helpful extra constants 762See C<aio_stat> for info about some potentially helpful extra constants
632and functions. 763and functions.
633 764
634=item aio_link $srcpath, $dstpath, $callback->($status) 765=item aio_link $srcpath, $dstpath, $callback->($status)
641 772
642Asynchronously create a new symbolic link to the existing object at C<$srcpath> at 773Asynchronously create a new symbolic link to the existing object at C<$srcpath> at
643the path C<$dstpath> and call the callback with the result code. 774the path C<$dstpath> and call the callback with the result code.
644 775
645 776
646=item aio_readlink $path, $callback->($link) 777=item aio_readlink $pathname, $callback->($link)
647 778
648Asynchronously read the symlink specified by C<$path> and pass it to 779Asynchronously read the symlink specified by C<$path> and pass it to
649the callback. If an error occurs, nothing or undef gets passed to the 780the callback. If an error occurs, nothing or undef gets passed to the
650callback. 781callback.
651 782
652 783
653=item aio_realpath $path, $callback->($path) 784=item aio_realpath $pathname, $callback->($path)
654 785
655Asynchronously make the path absolute and resolve any symlinks in 786Asynchronously make the path absolute and resolve any symlinks in
656C<$path>. The resulting path only consists of directories (Same as 787C<$path>. The resulting path only consists of directories (same as
657L<Cwd::realpath>). 788L<Cwd::realpath>).
658 789
659This request can be used to get the absolute path of the current working 790This request can be used to get the absolute path of the current working
660directory by passing it a path of F<.> (a single dot). 791directory by passing it a path of F<.> (a single dot).
661 792
662 793
663=item aio_rename $srcpath, $dstpath, $callback->($status) 794=item aio_rename $srcpath, $dstpath, $callback->($status)
664 795
665Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as 796Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as
666rename(2) and call the callback with the result code. 797rename(2) and call the callback with the result code.
798
799On systems that support the AIO::WD working directory abstraction
800natively, the case C<[$wd, "."]> as C<$srcpath> is specialcased - instead
801of failing, C<rename> is called on the absolute path of C<$wd>.
667 802
668 803
669=item aio_mkdir $pathname, $mode, $callback->($status) 804=item aio_mkdir $pathname, $mode, $callback->($status)
670 805
671Asynchronously mkdir (create) a directory and call the callback with 806Asynchronously mkdir (create) a directory and call the callback with
675 810
676=item aio_rmdir $pathname, $callback->($status) 811=item aio_rmdir $pathname, $callback->($status)
677 812
678Asynchronously rmdir (delete) a directory and call the callback with the 813Asynchronously rmdir (delete) a directory and call the callback with the
679result code. 814result code.
815
816On systems that support the AIO::WD working directory abstraction
817natively, the case C<[$wd, "."]> is specialcased - instead of failing,
818C<rmdir> is called on the absolute path of C<$wd>.
680 819
681 820
682=item aio_readdir $pathname, $callback->($entries) 821=item aio_readdir $pathname, $callback->($entries)
683 822
684Unlike the POSIX call of the same name, C<aio_readdir> reads an entire 823Unlike the POSIX call of the same name, C<aio_readdir> reads an entire
753C<$type>'s are known, which can be used to speed up some algorithms. 892C<$type>'s are known, which can be used to speed up some algorithms.
754 893
755=back 894=back
756 895
757 896
758=item aio_load $path, $data, $callback->($status) 897=item aio_load $pathname, $data, $callback->($status)
759 898
760This is a composite request that tries to fully load the given file into 899This is a composite request that tries to fully load the given file into
761memory. Status is the same as with aio_read. 900memory. Status is the same as with aio_read.
762 901
763=cut 902=cut
898 }; 1037 };
899 1038
900 $grp 1039 $grp
901} 1040}
902 1041
903=item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs) 1042=item aio_scandir $pathname, $maxreq, $callback->($dirs, $nondirs)
904 1043
905Scans a directory (similar to C<aio_readdir>) but additionally tries to 1044Scans a directory (similar to C<aio_readdir>) but additionally tries to
906efficiently separate the entries of directory C<$path> into two sets of 1045efficiently separate the entries of directory C<$path> into two sets of
907names, directories you can recurse into (directories), and ones you cannot 1046names, directories you can recurse into (directories), and ones you cannot
908recurse into (everything else, including symlinks to directories). 1047recurse into (everything else, including symlinks to directories).
965 1104
966 my $grp = aio_group $cb; 1105 my $grp = aio_group $cb;
967 1106
968 $maxreq = 4 if $maxreq <= 0; 1107 $maxreq = 4 if $maxreq <= 0;
969 1108
970 # stat once 1109 # get a wd object
971 aioreq_pri $pri; 1110 aioreq_pri $pri;
972 add $grp aio_stat $path, sub { 1111 add $grp aio_wd $path, sub {
1112 $_[0]
973 return $grp->result () if $_[0]; 1113 or return $grp->result ();
974 my $now = time;
975 my $hash1 = join ":", (stat _)[0,1,3,7,9];
976 1114
977 # read the directory entries 1115 my $wd = [shift, "."];
1116
1117 # stat once
978 aioreq_pri $pri; 1118 aioreq_pri $pri;
979 add $grp aio_readdirx $path, READDIR_DIRS_FIRST, sub { 1119 add $grp aio_stat $wd, sub {
980 my $entries = shift
981 or return $grp->result (); 1120 return $grp->result () if $_[0];
1121 my $now = time;
1122 my $hash1 = join ":", (stat _)[0,1,3,7,9];
982 1123
983 # stat the dir another time 1124 # read the directory entries
984 aioreq_pri $pri; 1125 aioreq_pri $pri;
1126 add $grp aio_readdirx $wd, READDIR_DIRS_FIRST, sub {
1127 my $entries = shift
1128 or return $grp->result ();
1129
1130 # stat the dir another time
1131 aioreq_pri $pri;
985 add $grp aio_stat $path, sub { 1132 add $grp aio_stat $wd, sub {
986 my $hash2 = join ":", (stat _)[0,1,3,7,9]; 1133 my $hash2 = join ":", (stat _)[0,1,3,7,9];
987 1134
988 my $ndirs; 1135 my $ndirs;
989 1136
990 # take the slow route if anything looks fishy 1137 # take the slow route if anything looks fishy
991 if ($hash1 ne $hash2 or (stat _)[9] == $now) { 1138 if ($hash1 ne $hash2 or (stat _)[9] == $now) {
992 $ndirs = -1; 1139 $ndirs = -1;
993 } else { 1140 } else {
994 # if nlink == 2, we are finished 1141 # if nlink == 2, we are finished
995 # for non-posix-fs's, we rely on nlink < 2 1142 # for non-posix-fs's, we rely on nlink < 2
996 $ndirs = (stat _)[3] - 2 1143 $ndirs = (stat _)[3] - 2
997 or return $grp->result ([], $entries); 1144 or return $grp->result ([], $entries);
998 } 1145 }
999 1146
1000 my (@dirs, @nondirs); 1147 my (@dirs, @nondirs);
1001 1148
1002 my $statgrp = add $grp aio_group sub { 1149 my $statgrp = add $grp aio_group sub {
1003 $grp->result (\@dirs, \@nondirs); 1150 $grp->result (\@dirs, \@nondirs);
1004 }; 1151 };
1005 1152
1006 limit $statgrp $maxreq; 1153 limit $statgrp $maxreq;
1007 feed $statgrp sub { 1154 feed $statgrp sub {
1008 return unless @$entries; 1155 return unless @$entries;
1009 my $entry = shift @$entries; 1156 my $entry = shift @$entries;
1010 1157
1011 aioreq_pri $pri; 1158 aioreq_pri $pri;
1159 $wd->[1] = "$entry/.";
1012 add $statgrp aio_stat "$path/$entry/.", sub { 1160 add $statgrp aio_stat $wd, sub {
1013 if ($_[0] < 0) { 1161 if ($_[0] < 0) {
1014 push @nondirs, $entry; 1162 push @nondirs, $entry;
1015 } else { 1163 } else {
1016 # need to check for real directory 1164 # need to check for real directory
1017 aioreq_pri $pri; 1165 aioreq_pri $pri;
1166 $wd->[1] = $entry;
1018 add $statgrp aio_lstat "$path/$entry", sub { 1167 add $statgrp aio_lstat $wd, sub {
1019 if (-d _) { 1168 if (-d _) {
1020 push @dirs, $entry; 1169 push @dirs, $entry;
1021 1170
1022 unless (--$ndirs) { 1171 unless (--$ndirs) {
1023 push @nondirs, @$entries; 1172 push @nondirs, @$entries;
1024 feed $statgrp; 1173 feed $statgrp;
1174 }
1175 } else {
1176 push @nondirs, $entry;
1025 } 1177 }
1026 } else {
1027 push @nondirs, $entry;
1028 } 1178 }
1029 } 1179 }
1030 } 1180 };
1031 }; 1181 };
1032 }; 1182 };
1033 }; 1183 };
1034 }; 1184 };
1035 }; 1185 };
1036 1186
1037 $grp 1187 $grp
1038} 1188}
1039 1189
1040=item aio_rmtree $path, $callback->($status) 1190=item aio_rmtree $pathname, $callback->($status)
1041 1191
1042Delete a directory tree starting (and including) C<$path>, return the 1192Delete a directory tree starting (and including) C<$path>, return the
1043status of the final C<rmdir> only. This is a composite request that 1193status of the final C<rmdir> only. This is a composite request that
1044uses C<aio_scandir> to recurse into and rmdir directories, and unlink 1194uses C<aio_scandir> to recurse into and rmdir directories, and unlink
1045everything else. 1195everything else.
1046 1196
1047=cut 1197=cut
1048 1198
1106C<$flags> can be a combination of C<IO::AIO::SYNC_FILE_RANGE_WAIT_BEFORE>, 1256C<$flags> can be a combination of C<IO::AIO::SYNC_FILE_RANGE_WAIT_BEFORE>,
1107C<IO::AIO::SYNC_FILE_RANGE_WRITE> and 1257C<IO::AIO::SYNC_FILE_RANGE_WRITE> and
1108C<IO::AIO::SYNC_FILE_RANGE_WAIT_AFTER>: refer to the sync_file_range 1258C<IO::AIO::SYNC_FILE_RANGE_WAIT_AFTER>: refer to the sync_file_range
1109manpage for details. 1259manpage for details.
1110 1260
1111=item aio_pathsync $path, $callback->($status) 1261=item aio_pathsync $pathname, $callback->($status)
1112 1262
1113This request tries to open, fsync and close the given path. This is a 1263This request tries to open, fsync and close the given path. This is a
1114composite request intended to sync directories after directory operations 1264composite request intended to sync directories after directory operations
1115(E.g. rename). This might not work on all operating systems or have any 1265(E.g. rename). This might not work on all operating systems or have any
1116specific effect, but usually it makes sure that directory changes get 1266specific effect, but usually it makes sure that directory changes get
1168 1318
1169This is a rather advanced IO::AIO call, which works best on mmap(2)ed 1319This is a rather advanced IO::AIO call, which works best on mmap(2)ed
1170scalars. 1320scalars.
1171 1321
1172It touches (reads or writes) all memory pages in the specified 1322It touches (reads or writes) all memory pages in the specified
1173range inside the scalar. All caveats and parameters are the same 1323range inside the scalar. All caveats and parameters are the same
1174as for C<aio_msync>, above, except for flags, which must be either 1324as for C<aio_msync>, above, except for flags, which must be either
1175C<0> (which reads all pages and ensures they are instantiated) or 1325C<0> (which reads all pages and ensures they are instantiated) or
1176C<IO::AIO::MT_MODIFY>, which modifies the memory page s(by reading and 1326C<IO::AIO::MT_MODIFY>, which modifies the memory pages (by reading and
1177writing an octet from it, which dirties the page). 1327writing an octet from it, which dirties the page).
1178 1328
1179=item aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status) 1329=item aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status)
1180 1330
1181This is a rather advanced IO::AIO call, which works best on mmap(2)ed 1331This is a rather advanced IO::AIO call, which works best on mmap(2)ed
1212documented under L<MISCELLANEOUS FUNCTIONS>. 1362documented under L<MISCELLANEOUS FUNCTIONS>.
1213 1363
1214Example: asynchronously lock all current and future pages into memory. 1364Example: asynchronously lock all current and future pages into memory.
1215 1365
1216 aio_mlockall IO::AIO::MCL_FUTURE; 1366 aio_mlockall IO::AIO::MCL_FUTURE;
1367
1368=item aio_fiemap $fh, $start, $length, $flags, $count, $cb->(\@extents)
1369
1370Queries the extents of the given file (by calling the Linux C<FIEMAP>
1371ioctl, see L<http://cvs.schmorp.de/IO-AIO/doc/fiemap.txt> for details). If
1372the ioctl is not available on your OS, then this request will fail with
1373C<ENOSYS>.
1374
1375C<$start> is the starting offset to query extents for, C<$length> is the
1376size of the range to query - if it is C<undef>, then the whole file will
1377be queried.
1378
1379C<$flags> is a combination of flags (C<IO::AIO::FIEMAP_FLAG_SYNC> or
1380C<IO::AIO::FIEMAP_FLAG_XATTR> - C<IO::AIO::FIEMAP_FLAGS_COMPAT> is also
1381exported), and is normally C<0> or C<IO::AIO::FIEMAP_FLAG_SYNC> to query
1382the data portion.
1383
1384C<$count> is the maximum number of extent records to return. If it is
1385C<undef>, then IO::AIO queries all extents of the range. As a very special
1386case, if it is C<0>, then the callback receives the number of extents
1387instead of the extents themselves (which is unreliable, see below).
1388
1389If an error occurs, the callback receives no arguments. The special
1390C<errno> value C<IO::AIO::EBADR> is available to test for flag errors.
1391
1392Otherwise, the callback receives an array reference with extent
1393structures. Each extent structure is an array reference itself, with the
1394following members:
1395
1396 [$logical, $physical, $length, $flags]
1397
1398Flags is any combination of the following flag values (typically either C<0>
1399or C<IO::AIO::FIEMAP_EXTENT_LAST> (1)):
1400
1401C<IO::AIO::FIEMAP_EXTENT_LAST>, C<IO::AIO::FIEMAP_EXTENT_UNKNOWN>,
1402C<IO::AIO::FIEMAP_EXTENT_DELALLOC>, C<IO::AIO::FIEMAP_EXTENT_ENCODED>,
1403C<IO::AIO::FIEMAP_EXTENT_DATA_ENCRYPTED>, C<IO::AIO::FIEMAP_EXTENT_NOT_ALIGNED>,
1404C<IO::AIO::FIEMAP_EXTENT_DATA_INLINE>, C<IO::AIO::FIEMAP_EXTENT_DATA_TAIL>,
1405C<IO::AIO::FIEMAP_EXTENT_UNWRITTEN>, C<IO::AIO::FIEMAP_EXTENT_MERGED> or
1406C<IO::AIO::FIEMAP_EXTENT_SHARED>.
1407
1408At the time of this writing (Linux 3.2), this requets is unreliable unless
1409C<$count> is C<undef>, as the kernel has all sorts of bugs preventing
1410it to return all extents of a range for files with large number of
1411extents. The code works around all these issues if C<$count> is undef.
1217 1412
1218=item aio_group $callback->(...) 1413=item aio_group $callback->(...)
1219 1414
1220This is a very special aio request: Instead of doing something, it is a 1415This is a very special aio request: Instead of doing something, it is a
1221container for other aio requests, which is useful if you want to bundle 1416container for other aio requests, which is useful if you want to bundle
1258like sleep and file handle readable/writable, the overhead this creates is 1453like sleep and file handle readable/writable, the overhead this creates is
1259immense (it blocks a thread for a long time) so do not use this function 1454immense (it blocks a thread for a long time) so do not use this function
1260except to put your application under artificial I/O pressure. 1455except to put your application under artificial I/O pressure.
1261 1456
1262=back 1457=back
1458
1459
1460=head2 IO::AIO::WD - multiple working directories
1461
1462Your process only has one current working directory, which is used by all
1463threads. This makes it hard to use relative paths (some other component
1464could call C<chdir> at any time, and it is hard to control when the path
1465will be used by IO::AIO).
1466
1467One solution for this is to always use absolute paths. This usually works,
1468but can be quite slow (the kernel has to walk the whole path on every
1469access), and can also be a hassle to implement.
1470
1471Newer POSIX systems have a number of functions (openat, fdopendir,
1472futimensat and so on) that make it possible to specify working directories
1473per operation.
1474
1475For portability, and because the clowns who "designed", or shall I write,
1476perpetrated this new interface were obviously half-drunk, this abstraction
1477cannot be perfect, though.
1478
1479IO::AIO allows you to convert directory paths into a so-called IO::AIO::WD
1480object. This object stores the canonicalised, absolute version of the
1481path, and on systems that allow it, also a directory file descriptor.
1482
1483Everywhere where a pathname is accepted by IO::AIO (e.g. in C<aio_stat>
1484or C<aio_unlink>), one can specify an array reference with an IO::AIO::WD
1485object and a pathname instead (or the IO::AIO::WD object alone, which
1486gets interpreted as C<[$wd, "."]>). If the pathname is absolute, the
1487IO::AIO::WD object is ignored, otherwise the pathname is resolved relative
1488to that IO::AIO::WD object.
1489
1490For example, to get a wd object for F</etc> and then stat F<passwd>
1491inside, you would write:
1492
1493 aio_wd "/etc", sub {
1494 my $etcdir = shift;
1495
1496 # although $etcdir can be undef on error, there is generally no reason
1497 # to check for errors here, as aio_stat will fail with ENOENT
1498 # when $etcdir is undef.
1499
1500 aio_stat [$etcdir, "passwd"], sub {
1501 # yay
1502 };
1503 };
1504
1505That C<aio_wd> is a request and not a normal function shows that creating
1506an IO::AIO::WD object is itself a potentially blocking operation, which is
1507why it is done asynchronously.
1508
1509To stat the directory obtained with C<aio_wd> above, one could write
1510either of the following three request calls:
1511
1512 aio_lstat "/etc" , sub { ... # pathname as normal string
1513 aio_lstat [$wd, "."], sub { ... # "." relative to $wd (i.e. $wd itself)
1514 aio_lstat $wd , sub { ... # shorthand for the previous
1515
1516As with normal pathnames, IO::AIO keeps a copy of the working directory
1517object and the pathname string, so you could write the following without
1518causing any issues due to C<$path> getting reused:
1519
1520 my $path = [$wd, undef];
1521
1522 for my $name (qw(abc def ghi)) {
1523 $path->[1] = $name;
1524 aio_stat $path, sub {
1525 # ...
1526 };
1527 }
1528
1529There are some caveats: when directories get renamed (or deleted), the
1530pathname string doesn't change, so will point to the new directory (or
1531nowhere at all), while the directory fd, if available on the system,
1532will still point to the original directory. Most functions accepting a
1533pathname will use the directory fd on newer systems, and the string on
1534older systems. Some functions (such as realpath) will always rely on the
1535string form of the pathname.
1536
1537So this functionality is mainly useful to get some protection against
1538C<chdir>, to easily get an absolute path out of a relative path for future
1539reference, and to speed up doing many operations in the same directory
1540(e.g. when stat'ing all files in a directory).
1541
1542The following functions implement this working directory abstraction:
1543
1544=over 4
1545
1546=item aio_wd $pathname, $callback->($wd)
1547
1548Asynchonously canonicalise the given pathname and convert it to an
1549IO::AIO::WD object representing it. If possible and supported on the
1550system, also open a directory fd to speed up pathname resolution relative
1551to this working directory.
1552
1553If something goes wrong, then C<undef> is passwd to the callback instead
1554of a working directory object and C<$!> is set appropriately. Since
1555passing C<undef> as working directory component of a pathname fails the
1556request with C<ENOENT>, there is often no need for error checking in the
1557C<aio_wd> callback, as future requests using the value will fail in the
1558expected way.
1559
1560If this call isn't available because your OS lacks it or it couldn't be
1561detected, it will be emulated by calling C<fsync> instead.
1562
1563=item IO::AIO::CWD
1564
1565This is a compiletime constant (object) that represents the process
1566current working directory.
1567
1568Specifying this object as working directory object for a pathname is as if
1569the pathname would be specified directly, without a directory object. For
1570example, these calls are functionally identical:
1571
1572 aio_stat "somefile", sub { ... };
1573 aio_stat [IO::AIO::CWD, "somefile"], sub { ... };
1574
1575=back
1576
1577To recover the path associated with an IO::AIO::WD object, you can use
1578C<aio_realpath>:
1579
1580 aio_realpath $wd, sub {
1581 warn "path is $_[0]\n";
1582 };
1583
1584Currently, C<aio_statvfs> always, and C<aio_rename> and C<aio_rmdir>
1585sometimes, fall back to using an absolue path.
1263 1586
1264=head2 IO::AIO::REQ CLASS 1587=head2 IO::AIO::REQ CLASS
1265 1588
1266All non-aggregate C<aio_*> functions return an object of this class when 1589All non-aggregate C<aio_*> functions return an object of this class when
1267called in non-void context. 1590called in non-void context.
1385 1708
1386Sets a feeder/generator on this group: every group can have an attached 1709Sets a feeder/generator on this group: every group can have an attached
1387generator that generates requests if idle. The idea behind this is that, 1710generator that generates requests if idle. The idea behind this is that,
1388although you could just queue as many requests as you want in a group, 1711although you could just queue as many requests as you want in a group,
1389this might starve other requests for a potentially long time. For example, 1712this might starve other requests for a potentially long time. For example,
1390C<aio_scandir> might generate hundreds of thousands C<aio_stat> requests, 1713C<aio_scandir> might generate hundreds of thousands of C<aio_stat>
1391delaying any later requests for a long time. 1714requests, delaying any later requests for a long time.
1392 1715
1393To avoid this, and allow incremental generation of requests, you can 1716To avoid this, and allow incremental generation of requests, you can
1394instead a group and set a feeder on it that generates those requests. The 1717instead a group and set a feeder on it that generates those requests. The
1395feed callback will be called whenever there are few enough (see C<limit>, 1718feed callback will be called whenever there are few enough (see C<limit>,
1396below) requests active in the group itself and is expected to queue more 1719below) requests active in the group itself and is expected to queue more
1445 1768
1446See C<poll_cb> for an example. 1769See C<poll_cb> for an example.
1447 1770
1448=item IO::AIO::poll_cb 1771=item IO::AIO::poll_cb
1449 1772
1450Process some outstanding events on the result pipe. You have to call 1773Process some requests that have reached the result phase (i.e. they have
1774been executed but the results are not yet reported). You have to call
1775this "regularly" to finish outstanding requests.
1776
1451this regularly. Returns C<0> if all events could be processed (or there 1777Returns C<0> if all events could be processed (or there were no
1452were no events to process), or C<-1> if it returned earlier for whatever 1778events to process), or C<-1> if it returned earlier for whatever
1453reason. Returns immediately when no events are outstanding. The amount of 1779reason. Returns immediately when no events are outstanding. The amount
1454events processed depends on the settings of C<IO::AIO::max_poll_req> and 1780of events processed depends on the settings of C<IO::AIO::max_poll_req>,
1455C<IO::AIO::max_poll_time>. 1781C<IO::AIO::max_poll_time> and C<IO::AIO::max_outstanding>.
1456 1782
1457If not all requests were processed for whatever reason, the filehandle 1783If not all requests were processed for whatever reason, the poll file
1458will still be ready when C<poll_cb> returns, so normally you don't have to 1784descriptor will still be ready when C<poll_cb> returns, so normally you
1459do anything special to have it called later. 1785don't have to do anything special to have it called later.
1460 1786
1461Apart from calling C<IO::AIO::poll_cb> when the event filehandle becomes 1787Apart from calling C<IO::AIO::poll_cb> when the event filehandle becomes
1462ready, it can be beneficial to call this function from loops which submit 1788ready, it can be beneficial to call this function from loops which submit
1463a lot of requests, to make sure the results get processed when they become 1789a lot of requests, to make sure the results get processed when they become
1464available and not just when the loop is finished and the event loop takes 1790available and not just when the loop is finished and the event loop takes
1473 poll => 'r', async => 1, 1799 poll => 'r', async => 1,
1474 cb => \&IO::AIO::poll_cb); 1800 cb => \&IO::AIO::poll_cb);
1475 1801
1476=item IO::AIO::poll_wait 1802=item IO::AIO::poll_wait
1477 1803
1478If there are any outstanding requests and none of them in the result 1804Wait until either at least one request is in the result phase or no
1479phase, wait till the result filehandle becomes ready for reading (simply 1805requests are outstanding anymore.
1480does a C<select> on the filehandle. This is useful if you want to 1806
1481synchronously wait for some requests to finish). 1807This is useful if you want to synchronously wait for some requests to
1808become ready, without actually handling them.
1482 1809
1483See C<nreqs> for an example. 1810See C<nreqs> for an example.
1484 1811
1485=item IO::AIO::poll 1812=item IO::AIO::poll
1486 1813
1705ENOSYS, otherwise the return value of C<mprotect>. 2032ENOSYS, otherwise the return value of C<mprotect>.
1706 2033
1707=item IO::AIO::mmap $scalar, $length, $prot, $flags, $fh[, $offset] 2034=item IO::AIO::mmap $scalar, $length, $prot, $flags, $fh[, $offset]
1708 2035
1709Memory-maps a file (or anonymous memory range) and attaches it to the 2036Memory-maps a file (or anonymous memory range) and attaches it to the
1710given C<$scalar>, which will act like a string scalar. 2037given C<$scalar>, which will act like a string scalar. Returns true on
2038success, and false otherwise.
1711 2039
1712The only operations allowed on the scalar are C<substr>/C<vec> that don't 2040The only operations allowed on the scalar are C<substr>/C<vec> that don't
1713change the string length, and most read-only operations such as copying it 2041change the string length, and most read-only operations such as copying it
1714or searching it with regexes and so on. 2042or searching it with regexes and so on.
1715 2043
1768Calls the C<munlockall> function. 2096Calls the C<munlockall> function.
1769 2097
1770On systems that do not implement C<munlockall>, this function returns 2098On systems that do not implement C<munlockall>, this function returns
1771ENOSYS, otherwise the return value of C<munlockall>. 2099ENOSYS, otherwise the return value of C<munlockall>.
1772 2100
2101=item IO::AIO::splice $r_fh, $r_off, $w_fh, $w_off, $length, $flags
2102
2103Calls the GNU/Linux C<splice(2)> syscall, if available. If C<$r_off> or
2104C<$w_off> are C<undef>, then C<NULL> is passed for these, otherwise they
2105should be the file offset.
2106
2107C<$r_fh> and C<$w_fh> should not refer to the same file, as splice might
2108silently corrupt the data in this case.
2109
2110The following symbol flag values are available: C<IO::AIO::SPLICE_F_MOVE>,
2111C<IO::AIO::SPLICE_F_NONBLOCK>, C<IO::AIO::SPLICE_F_MORE> and
2112C<IO::AIO::SPLICE_F_GIFT>.
2113
2114See the C<splice(2)> manpage for details.
2115
2116=item IO::AIO::tee $r_fh, $w_fh, $length, $flags
2117
2118Calls the GNU/Linux C<tee(2)> syscall, see it's manpage and the
2119description for C<IO::AIO::splice> above for details.
2120
2121=item $actual_size = IO::AIO::pipesize $r_fh[, $new_size]
2122
2123Attempts to query or change the pipe buffer size. Obviously works only
2124on pipes, and currently works only on GNU/Linux systems, and fails with
2125C<-1>/C<ENOSYS> everywhere else. If anybody knows how to influence pipe buffer
2126size on other systems, drop me a note.
2127
1773=back 2128=back
1774 2129
1775=cut 2130=cut
1776 2131
1777min_parallel 8; 2132min_parallel 8;

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