ViewVC Help
View File | Revision Log | Show Annotations | Download File
/cvs/IO-AIO/AIO.pm
(Generate patch)

Comparing IO-AIO/AIO.pm (file contents):
Revision 1.212 by root, Thu Sep 29 22:42:15 2011 UTC vs.
Revision 1.258 by root, Thu Jan 21 23:04:46 2016 UTC

68=head2 EXAMPLE 68=head2 EXAMPLE
69 69
70This is a simple example that uses the EV module and loads 70This is a simple example that uses the EV module and loads
71F</etc/passwd> asynchronously: 71F</etc/passwd> asynchronously:
72 72
73 use Fcntl;
74 use EV; 73 use EV;
75 use IO::AIO; 74 use IO::AIO;
76 75
77 # register the IO::AIO callback with EV 76 # register the IO::AIO callback with EV
78 my $aio_w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb; 77 my $aio_w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb;
95 94
96 # file contents now in $contents 95 # file contents now in $contents
97 print $contents; 96 print $contents;
98 97
99 # exit event loop and program 98 # exit event loop and program
100 EV::unloop; 99 EV::break;
101 }; 100 };
102 }; 101 };
103 102
104 # possibly queue up other requests, or open GUI windows, 103 # possibly queue up other requests, or open GUI windows,
105 # check for sockets etc. etc. 104 # check for sockets etc. etc.
106 105
107 # process events as long as there are some: 106 # process events as long as there are some:
108 EV::loop; 107 EV::run;
109 108
110=head1 REQUEST ANATOMY AND LIFETIME 109=head1 REQUEST ANATOMY AND LIFETIME
111 110
112Every C<aio_*> function creates a request. which is a C data structure not 111Every C<aio_*> function creates a request. which is a C data structure not
113directly visible to Perl. 112directly visible to Perl.
168use common::sense; 167use common::sense;
169 168
170use base 'Exporter'; 169use base 'Exporter';
171 170
172BEGIN { 171BEGIN {
173 our $VERSION = '4.0'; 172 our $VERSION = 4.33;
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 $pathname, $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 $pathname, $callback->($link) 231 aio_readlink $pathname, $callback->($link)
230 aio_realpath $pathname, $callback->($link) 232 aio_realpath $pathname, $callback->($path)
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 $pathname, $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 $pathname, $maxreq, $callback->($dirs, $nondirs)
242 aio_rmtree $pathname, $callback->($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)
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 be called after 290which must be a code reference. This code reference will be called after
317correct contents. 321correct contents.
318 322
319This 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
320handles correctly whether it is set or not. 324handles correctly whether it is set or not.
321 325
326=head2 AIO REQUEST FUNCTIONS
327
322=over 4 328=over 4
323 329
324=item $prev_pri = aioreq_pri [$pri] 330=item $prev_pri = aioreq_pri [$pri]
325 331
326Returns the priority value that would be used for the next request and, if 332Returns the priority value that would be used for the next request and, if
355 361
356 362
357=item aio_open $pathname, $flags, $mode, $callback->($fh) 363=item aio_open $pathname, $flags, $mode, $callback->($fh)
358 364
359Asynchronously 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
360created filehandle for the file. 366created filehandle for the file (or C<undef> in case of an error).
361 367
362The 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,
363for an explanation. 369for an explanation.
364 370
365The 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
388following POSIX and non-POSIX constants are available (missing ones on 394following POSIX and non-POSIX constants are available (missing ones on
389your system are, as usual, C<0>): 395your system are, as usual, C<0>):
390 396
391C<O_ASYNC>, C<O_DIRECT>, C<O_NOATIME>, C<O_CLOEXEC>, C<O_NOCTTY>, C<O_NOFOLLOW>, 397C<O_ASYNC>, C<O_DIRECT>, C<O_NOATIME>, C<O_CLOEXEC>, C<O_NOCTTY>, C<O_NOFOLLOW>,
392C<O_NONBLOCK>, C<O_EXEC>, C<O_SEARCH>, C<O_DIRECTORY>, C<O_DSYNC>, 398C<O_NONBLOCK>, C<O_EXEC>, C<O_SEARCH>, C<O_DIRECTORY>, C<O_DSYNC>,
393C<O_RSYNC>, C<O_SYNC> and C<O_TTY_INIT>. 399C<O_RSYNC>, C<O_SYNC>, C<O_PATH>, C<O_TMPFILE>, and C<O_TTY_INIT>.
394 400
395 401
396=item aio_close $fh, $callback->($status) 402=item aio_close $fh, $callback->($status)
397 403
398Asynchronously close a file and call the callback with the result 404Asynchronously close a file and call the callback with the result
407 413
408Or 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
409free for reuse until the perl filehandle is closed. 415free for reuse until the perl filehandle is closed.
410 416
411=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".
412 438
413=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval) 439=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
414 440
415=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval) 441=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
416 442
576 namemax => 255, 602 namemax => 255,
577 frsize => 1024, 603 frsize => 1024,
578 fsid => 1810 604 fsid => 1810
579 } 605 }
580 606
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/ext4
632 0x0000ef51 ext2
633 0xf2f52010 f2fs
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 0x00c0ffee hostfs
643 0x958458f6 hugetlbfs
644 0x2bad1dea inotifyfs
645 0x00009660 isofs
646 0x000072b6 jffs2
647 0x3153464a jfs
648 0x6b414653 k-afs
649 0x0bd00bd0 lustre
650 0x0000137f minix
651 0x0000138f minix 30 char names
652 0x00002468 minix v2
653 0x00002478 minix v2 30 char names
654 0x00004d5a minix v3
655 0x19800202 mqueue
656 0x00004d44 msdos
657 0x0000564c novell
658 0x00006969 nfs
659 0x6e667364 nfsd
660 0x00003434 nilfs
661 0x5346544e ntfs
662 0x00009fa1 openprom
663 0x7461636F ocfs2
664 0x00009fa0 proc
665 0x6165676c pstorefs
666 0x0000002f qnx4
667 0x68191122 qnx6
668 0x858458f6 ramfs
669 0x52654973 reiserfs
670 0x00007275 romfs
671 0x67596969 rpc_pipefs
672 0x73636673 securityfs
673 0xf97cff8c selinux
674 0x0000517b smb
675 0x534f434b sockfs
676 0x73717368 squashfs
677 0x62656572 sysfs
678 0x012ff7b6 sysv2
679 0x012ff7b5 sysv4
680 0x01021994 tmpfs
681 0x15013346 udf
682 0x00011954 ufs
683 0x54190100 ufs byteswapped
684 0x00009fa2 usbdevfs
685 0x01021997 v9fs
686 0xa501fcf5 vxfs
687 0xabba1974 xenfs
688 0x012ff7b4 xenix
689 0x58465342 xfs
690 0x012fd16d xia
581 691
582=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status) 692=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
583 693
584Works like perl's C<utime> function (including the special case of $atime 694Works like perl's C<utime> function (including the special case of $atime
585and $mtime being undef). Fractional times are supported if the underlying 695and $mtime being undef). Fractional times are supported if the underlying
613=item aio_truncate $fh_or_path, $offset, $callback->($status) 723=item aio_truncate $fh_or_path, $offset, $callback->($status)
614 724
615Works like truncate(2) or ftruncate(2). 725Works like truncate(2) or ftruncate(2).
616 726
617 727
728=item aio_allocate $fh, $mode, $offset, $len, $callback->($status)
729
730Allocates or frees disk space according to the C<$mode> argument. See the
731linux C<fallocate> documentation for details.
732
733C<$mode> is usually C<0> or C<IO::AIO::FALLOC_FL_KEEP_SIZE> to allocate
734space, or C<IO::AIO::FALLOC_FL_PUNCH_HOLE | IO::AIO::FALLOC_FL_KEEP_SIZE>,
735to deallocate a file range.
736
737IO::AIO also supports C<FALLOC_FL_COLLAPSE_RANGE>, to remove a range
738(without leaving a hole) and C<FALLOC_FL_ZERO_RANGE>, to zero a range (see
739your L<fallocate(2)> manpage).
740
741The file system block size used by C<fallocate> is presumably the
742C<f_bsize> returned by C<statvfs>.
743
744If C<fallocate> isn't available or cannot be emulated (currently no
745emulation will be attempted), passes C<-1> and sets C<$!> to C<ENOSYS>.
746
747
618=item aio_chmod $fh_or_path, $mode, $callback->($status) 748=item aio_chmod $fh_or_path, $mode, $callback->($status)
619 749
620Works like perl's C<chmod> function. 750Works like perl's C<chmod> function.
621 751
622 752
659 789
660 790
661=item aio_realpath $pathname, $callback->($path) 791=item aio_realpath $pathname, $callback->($path)
662 792
663Asynchronously make the path absolute and resolve any symlinks in 793Asynchronously make the path absolute and resolve any symlinks in
664C<$path>. The resulting path only consists of directories (Same as 794C<$path>. The resulting path only consists of directories (same as
665L<Cwd::realpath>). 795L<Cwd::realpath>).
666 796
667This request can be used to get the absolute path of the current working 797This request can be used to get the absolute path of the current working
668directory by passing it a path of F<.> (a single dot). 798directory by passing it a path of F<.> (a single dot).
669 799
670 800
671=item aio_rename $srcpath, $dstpath, $callback->($status) 801=item aio_rename $srcpath, $dstpath, $callback->($status)
672 802
673Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as 803Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as
674rename(2) and call the callback with the result code. 804rename(2) and call the callback with the result code.
805
806On systems that support the AIO::WD working directory abstraction
807natively, the case C<[$wd, "."]> as C<$srcpath> is specialcased - instead
808of failing, C<rename> is called on the absolute path of C<$wd>.
675 809
676 810
677=item aio_mkdir $pathname, $mode, $callback->($status) 811=item aio_mkdir $pathname, $mode, $callback->($status)
678 812
679Asynchronously mkdir (create) a directory and call the callback with 813Asynchronously mkdir (create) a directory and call the callback with
683 817
684=item aio_rmdir $pathname, $callback->($status) 818=item aio_rmdir $pathname, $callback->($status)
685 819
686Asynchronously rmdir (delete) a directory and call the callback with the 820Asynchronously rmdir (delete) a directory and call the callback with the
687result code. 821result code.
822
823On systems that support the AIO::WD working directory abstraction
824natively, the case C<[$wd, "."]> is specialcased - instead of failing,
825C<rmdir> is called on the absolute path of C<$wd>.
688 826
689 827
690=item aio_readdir $pathname, $callback->($entries) 828=item aio_readdir $pathname, $callback->($entries)
691 829
692Unlike the POSIX call of the same name, C<aio_readdir> reads an entire 830Unlike the POSIX call of the same name, C<aio_readdir> reads an entire
1057} 1195}
1058 1196
1059=item aio_rmtree $pathname, $callback->($status) 1197=item aio_rmtree $pathname, $callback->($status)
1060 1198
1061Delete a directory tree starting (and including) C<$path>, return the 1199Delete a directory tree starting (and including) C<$path>, return the
1062status of the final C<rmdir> only. This is a composite request that 1200status of the final C<rmdir> only. This is a composite request that
1063uses C<aio_scandir> to recurse into and rmdir directories, and unlink 1201uses C<aio_scandir> to recurse into and rmdir directories, and unlink
1064everything else. 1202everything else.
1065 1203
1066=cut 1204=cut
1067 1205
1187 1325
1188This is a rather advanced IO::AIO call, which works best on mmap(2)ed 1326This is a rather advanced IO::AIO call, which works best on mmap(2)ed
1189scalars. 1327scalars.
1190 1328
1191It touches (reads or writes) all memory pages in the specified 1329It touches (reads or writes) all memory pages in the specified
1192range inside the scalar. All caveats and parameters are the same 1330range inside the scalar. All caveats and parameters are the same
1193as for C<aio_msync>, above, except for flags, which must be either 1331as for C<aio_msync>, above, except for flags, which must be either
1194C<0> (which reads all pages and ensures they are instantiated) or 1332C<0> (which reads all pages and ensures they are instantiated) or
1195C<IO::AIO::MT_MODIFY>, which modifies the memory page s(by reading and 1333C<IO::AIO::MT_MODIFY>, which modifies the memory pages (by reading and
1196writing an octet from it, which dirties the page). 1334writing an octet from it, which dirties the page).
1197 1335
1198=item aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status) 1336=item aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status)
1199 1337
1200This is a rather advanced IO::AIO call, which works best on mmap(2)ed 1338This is a rather advanced IO::AIO call, which works best on mmap(2)ed
1231documented under L<MISCELLANEOUS FUNCTIONS>. 1369documented under L<MISCELLANEOUS FUNCTIONS>.
1232 1370
1233Example: asynchronously lock all current and future pages into memory. 1371Example: asynchronously lock all current and future pages into memory.
1234 1372
1235 aio_mlockall IO::AIO::MCL_FUTURE; 1373 aio_mlockall IO::AIO::MCL_FUTURE;
1374
1375=item aio_fiemap $fh, $start, $length, $flags, $count, $cb->(\@extents)
1376
1377Queries the extents of the given file (by calling the Linux C<FIEMAP>
1378ioctl, see L<http://cvs.schmorp.de/IO-AIO/doc/fiemap.txt> for details). If
1379the ioctl is not available on your OS, then this request will fail with
1380C<ENOSYS>.
1381
1382C<$start> is the starting offset to query extents for, C<$length> is the
1383size of the range to query - if it is C<undef>, then the whole file will
1384be queried.
1385
1386C<$flags> is a combination of flags (C<IO::AIO::FIEMAP_FLAG_SYNC> or
1387C<IO::AIO::FIEMAP_FLAG_XATTR> - C<IO::AIO::FIEMAP_FLAGS_COMPAT> is also
1388exported), and is normally C<0> or C<IO::AIO::FIEMAP_FLAG_SYNC> to query
1389the data portion.
1390
1391C<$count> is the maximum number of extent records to return. If it is
1392C<undef>, then IO::AIO queries all extents of the range. As a very special
1393case, if it is C<0>, then the callback receives the number of extents
1394instead of the extents themselves (which is unreliable, see below).
1395
1396If an error occurs, the callback receives no arguments. The special
1397C<errno> value C<IO::AIO::EBADR> is available to test for flag errors.
1398
1399Otherwise, the callback receives an array reference with extent
1400structures. Each extent structure is an array reference itself, with the
1401following members:
1402
1403 [$logical, $physical, $length, $flags]
1404
1405Flags is any combination of the following flag values (typically either C<0>
1406or C<IO::AIO::FIEMAP_EXTENT_LAST> (1)):
1407
1408C<IO::AIO::FIEMAP_EXTENT_LAST>, C<IO::AIO::FIEMAP_EXTENT_UNKNOWN>,
1409C<IO::AIO::FIEMAP_EXTENT_DELALLOC>, C<IO::AIO::FIEMAP_EXTENT_ENCODED>,
1410C<IO::AIO::FIEMAP_EXTENT_DATA_ENCRYPTED>, C<IO::AIO::FIEMAP_EXTENT_NOT_ALIGNED>,
1411C<IO::AIO::FIEMAP_EXTENT_DATA_INLINE>, C<IO::AIO::FIEMAP_EXTENT_DATA_TAIL>,
1412C<IO::AIO::FIEMAP_EXTENT_UNWRITTEN>, C<IO::AIO::FIEMAP_EXTENT_MERGED> or
1413C<IO::AIO::FIEMAP_EXTENT_SHARED>.
1414
1415At the time of this writing (Linux 3.2), this requets is unreliable unless
1416C<$count> is C<undef>, as the kernel has all sorts of bugs preventing
1417it to return all extents of a range for files with large number of
1418extents. The code works around all these issues if C<$count> is undef.
1236 1419
1237=item aio_group $callback->(...) 1420=item aio_group $callback->(...)
1238 1421
1239This is a very special aio request: Instead of doing something, it is a 1422This is a very special aio request: Instead of doing something, it is a
1240container for other aio requests, which is useful if you want to bundle 1423container for other aio requests, which is useful if you want to bundle
1304object. This object stores the canonicalised, absolute version of the 1487object. This object stores the canonicalised, absolute version of the
1305path, and on systems that allow it, also a directory file descriptor. 1488path, and on systems that allow it, also a directory file descriptor.
1306 1489
1307Everywhere where a pathname is accepted by IO::AIO (e.g. in C<aio_stat> 1490Everywhere where a pathname is accepted by IO::AIO (e.g. in C<aio_stat>
1308or C<aio_unlink>), one can specify an array reference with an IO::AIO::WD 1491or C<aio_unlink>), one can specify an array reference with an IO::AIO::WD
1309object and a pathname instead. If the pathname is absolute, the 1492object and a pathname instead (or the IO::AIO::WD object alone, which
1493gets interpreted as C<[$wd, "."]>). If the pathname is absolute, the
1310IO::AIO::WD objetc is ignored, otherwise the pathname is resolved relative 1494IO::AIO::WD object is ignored, otherwise the pathname is resolved relative
1311to that IO::AIO::WD object. 1495to that IO::AIO::WD object.
1312 1496
1313For example, to get a wd object for F</etc> and then stat F<passwd> 1497For example, to get a wd object for F</etc> and then stat F<passwd>
1314inside, you would write: 1498inside, you would write:
1315 1499
1323 aio_stat [$etcdir, "passwd"], sub { 1507 aio_stat [$etcdir, "passwd"], sub {
1324 # yay 1508 # yay
1325 }; 1509 };
1326 }; 1510 };
1327 1511
1512The fact that C<aio_wd> is a request and not a normal function shows that
1328This shows that creating an IO::AIO::WD object is itself a potentially 1513creating an IO::AIO::WD object is itself a potentially blocking operation,
1329blocking operation, which is why it is done asynchronously. 1514which is why it is done asynchronously.
1515
1516To stat the directory obtained with C<aio_wd> above, one could write
1517either of the following three request calls:
1518
1519 aio_lstat "/etc" , sub { ... # pathname as normal string
1520 aio_lstat [$wd, "."], sub { ... # "." relative to $wd (i.e. $wd itself)
1521 aio_lstat $wd , sub { ... # shorthand for the previous
1330 1522
1331As with normal pathnames, IO::AIO keeps a copy of the working directory 1523As with normal pathnames, IO::AIO keeps a copy of the working directory
1332object and the pathname string, so you could write the following without 1524object and the pathname string, so you could write the following without
1333causing any issues due to C<$path> getting reused: 1525causing any issues due to C<$path> getting reused:
1334 1526
1347will still point to the original directory. Most functions accepting a 1539will still point to the original directory. Most functions accepting a
1348pathname will use the directory fd on newer systems, and the string on 1540pathname will use the directory fd on newer systems, and the string on
1349older systems. Some functions (such as realpath) will always rely on the 1541older systems. Some functions (such as realpath) will always rely on the
1350string form of the pathname. 1542string form of the pathname.
1351 1543
1352So this fucntionality is mainly useful to get some protection against 1544So this functionality is mainly useful to get some protection against
1353C<chdir>, to easily get an absolute path out of a relative path for future 1545C<chdir>, to easily get an absolute path out of a relative path for future
1354reference, and to speed up doing many operations in the same directory 1546reference, and to speed up doing many operations in the same directory
1355(e.g. when stat'ing all files in a directory). 1547(e.g. when stat'ing all files in a directory).
1356 1548
1357The following functions implement this working directory abstraction: 1549The following functions implement this working directory abstraction:
1370passing C<undef> as working directory component of a pathname fails the 1562passing C<undef> as working directory component of a pathname fails the
1371request with C<ENOENT>, there is often no need for error checking in the 1563request with C<ENOENT>, there is often no need for error checking in the
1372C<aio_wd> callback, as future requests using the value will fail in the 1564C<aio_wd> callback, as future requests using the value will fail in the
1373expected way. 1565expected way.
1374 1566
1375If this call isn't available because your OS lacks it or it couldn't be
1376detected, it will be emulated by calling C<fsync> instead.
1377
1378=item IO::AIO::CWD 1567=item IO::AIO::CWD
1379 1568
1380This is a compiletime constant (object) that represents the process 1569This is a compiletime constant (object) that represents the process
1381current working directory. 1570current working directory.
1382 1571
1383Specifying this object as working directory object for a pathname is as 1572Specifying this object as working directory object for a pathname is as if
1384if the pathname would be specified directly, without a directory object, 1573the pathname would be specified directly, without a directory object. For
1385e.g., these calls are functionally identical: 1574example, these calls are functionally identical:
1386 1575
1387 aio_stat "somefile", sub { ... }; 1576 aio_stat "somefile", sub { ... };
1388 aio_stat [IO::AIO::CWD, "somefile"], sub { ... }; 1577 aio_stat [IO::AIO::CWD, "somefile"], sub { ... };
1389 1578
1390=back 1579=back
1391 1580
1581To recover the path associated with an IO::AIO::WD object, you can use
1582C<aio_realpath>:
1583
1584 aio_realpath $wd, sub {
1585 warn "path is $_[0]\n";
1586 };
1587
1588Currently, C<aio_statvfs> always, and C<aio_rename> and C<aio_rmdir>
1589sometimes, fall back to using an absolue path.
1392 1590
1393=head2 IO::AIO::REQ CLASS 1591=head2 IO::AIO::REQ CLASS
1394 1592
1395All non-aggregate C<aio_*> functions return an object of this class when 1593All non-aggregate C<aio_*> functions return an object of this class when
1396called in non-void context. 1594called in non-void context.
1574 1772
1575See C<poll_cb> for an example. 1773See C<poll_cb> for an example.
1576 1774
1577=item IO::AIO::poll_cb 1775=item IO::AIO::poll_cb
1578 1776
1579Process some outstanding events on the result pipe. You have to call 1777Process some requests that have reached the result phase (i.e. they have
1778been executed but the results are not yet reported). You have to call
1779this "regularly" to finish outstanding requests.
1780
1580this regularly. Returns C<0> if all events could be processed (or there 1781Returns C<0> if all events could be processed (or there were no
1581were no events to process), or C<-1> if it returned earlier for whatever 1782events to process), or C<-1> if it returned earlier for whatever
1582reason. Returns immediately when no events are outstanding. The amount of 1783reason. Returns immediately when no events are outstanding. The amount
1583events processed depends on the settings of C<IO::AIO::max_poll_req> and 1784of events processed depends on the settings of C<IO::AIO::max_poll_req>,
1584C<IO::AIO::max_poll_time>. 1785C<IO::AIO::max_poll_time> and C<IO::AIO::max_outstanding>.
1585 1786
1586If not all requests were processed for whatever reason, the filehandle 1787If not all requests were processed for whatever reason, the poll file
1587will still be ready when C<poll_cb> returns, so normally you don't have to 1788descriptor will still be ready when C<poll_cb> returns, so normally you
1588do anything special to have it called later. 1789don't have to do anything special to have it called later.
1589 1790
1590Apart from calling C<IO::AIO::poll_cb> when the event filehandle becomes 1791Apart from calling C<IO::AIO::poll_cb> when the event filehandle becomes
1591ready, it can be beneficial to call this function from loops which submit 1792ready, it can be beneficial to call this function from loops which submit
1592a lot of requests, to make sure the results get processed when they become 1793a lot of requests, to make sure the results get processed when they become
1593available and not just when the loop is finished and the event loop takes 1794available and not just when the loop is finished and the event loop takes
1602 poll => 'r', async => 1, 1803 poll => 'r', async => 1,
1603 cb => \&IO::AIO::poll_cb); 1804 cb => \&IO::AIO::poll_cb);
1604 1805
1605=item IO::AIO::poll_wait 1806=item IO::AIO::poll_wait
1606 1807
1607If there are any outstanding requests and none of them in the result 1808Wait until either at least one request is in the result phase or no
1608phase, wait till the result filehandle becomes ready for reading (simply 1809requests are outstanding anymore.
1609does a C<select> on the filehandle. This is useful if you want to 1810
1610synchronously wait for some requests to finish). 1811This is useful if you want to synchronously wait for some requests to
1812become ready, without actually handling them.
1611 1813
1612See C<nreqs> for an example. 1814See C<nreqs> for an example.
1613 1815
1614=item IO::AIO::poll 1816=item IO::AIO::poll
1615 1817
1736 1938
1737This is a very bad function to use in interactive programs because it 1939This is a very bad function to use in interactive programs because it
1738blocks, and a bad way to reduce concurrency because it is inexact: Better 1940blocks, and a bad way to reduce concurrency because it is inexact: Better
1739use an C<aio_group> together with a feed callback. 1941use an C<aio_group> together with a feed callback.
1740 1942
1741It's main use is in scripts without an event loop - when you want to stat 1943Its main use is in scripts without an event loop - when you want to stat
1742a lot of files, you can write somehting like this: 1944a lot of files, you can write somehting like this:
1743 1945
1744 IO::AIO::max_outstanding 32; 1946 IO::AIO::max_outstanding 32;
1745 1947
1746 for my $path (...) { 1948 for my $path (...) {
1786 1988
1787=back 1989=back
1788 1990
1789=head3 MISCELLANEOUS FUNCTIONS 1991=head3 MISCELLANEOUS FUNCTIONS
1790 1992
1791IO::AIO implements some functions that might be useful, but are not 1993IO::AIO implements some functions that are useful when you want to use
1792asynchronous. 1994some "Advanced I/O" function not available to in Perl, without going the
1995"Asynchronous I/O" route. Many of these have an asynchronous C<aio_*>
1996counterpart.
1793 1997
1794=over 4 1998=over 4
1795 1999
1796=item IO::AIO::sendfile $ofh, $ifh, $offset, $count 2000=item IO::AIO::sendfile $ofh, $ifh, $offset, $count
1797 2001
1834ENOSYS, otherwise the return value of C<mprotect>. 2038ENOSYS, otherwise the return value of C<mprotect>.
1835 2039
1836=item IO::AIO::mmap $scalar, $length, $prot, $flags, $fh[, $offset] 2040=item IO::AIO::mmap $scalar, $length, $prot, $flags, $fh[, $offset]
1837 2041
1838Memory-maps a file (or anonymous memory range) and attaches it to the 2042Memory-maps a file (or anonymous memory range) and attaches it to the
1839given C<$scalar>, which will act like a string scalar. 2043given C<$scalar>, which will act like a string scalar. Returns true on
2044success, and false otherwise.
1840 2045
1841The only operations allowed on the scalar are C<substr>/C<vec> that don't 2046The only operations allowed on the scalar are C<substr>/C<vec> that don't
1842change the string length, and most read-only operations such as copying it 2047change the string length, and most read-only operations such as copying it
1843or searching it with regexes and so on. 2048or searching it with regexes and so on.
1844 2049
1855filesize. 2060filesize.
1856 2061
1857C<$prot> is a combination of C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_EXEC>, 2062C<$prot> is a combination of C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_EXEC>,
1858C<IO::AIO::PROT_READ> and/or C<IO::AIO::PROT_WRITE>, 2063C<IO::AIO::PROT_READ> and/or C<IO::AIO::PROT_WRITE>,
1859 2064
1860C<$flags> can be a combination of C<IO::AIO::MAP_SHARED> or 2065C<$flags> can be a combination of
1861C<IO::AIO::MAP_PRIVATE>, or a number of system-specific flags (when 2066C<IO::AIO::MAP_SHARED> or
1862not available, the are defined as 0): C<IO::AIO::MAP_ANONYMOUS> 2067C<IO::AIO::MAP_PRIVATE>,
2068or a number of system-specific flags (when not available, the are C<0>):
1863(which is set to C<MAP_ANON> if your system only provides this 2069C<IO::AIO::MAP_ANONYMOUS> (which is set to C<MAP_ANON> if your system only provides this constant),
1864constant), C<IO::AIO::MAP_HUGETLB>, C<IO::AIO::MAP_LOCKED>, 2070C<IO::AIO::MAP_LOCKED>,
1865C<IO::AIO::MAP_NORESERVE>, C<IO::AIO::MAP_POPULATE> or 2071C<IO::AIO::MAP_NORESERVE>,
2072C<IO::AIO::MAP_POPULATE>,
1866C<IO::AIO::MAP_NONBLOCK> 2073C<IO::AIO::MAP_NONBLOCK>,
2074C<IO::AIO::MAP_FIXED>,
2075C<IO::AIO::MAP_GROWSDOWN>,
2076C<IO::AIO::MAP_32BIT>,
2077C<IO::AIO::MAP_HUGETLB> or
2078C<IO::AIO::MAP_STACK>.
1867 2079
1868If C<$fh> is C<undef>, then a file descriptor of C<-1> is passed. 2080If C<$fh> is C<undef>, then a file descriptor of C<-1> is passed.
1869 2081
1870C<$offset> is the offset from the start of the file - it generally must be 2082C<$offset> is the offset from the start of the file - it generally must be
1871a multiple of C<IO::AIO::PAGESIZE> and defaults to C<0>. 2083a multiple of C<IO::AIO::PAGESIZE> and defaults to C<0>.
1896 2108
1897Calls the C<munlockall> function. 2109Calls the C<munlockall> function.
1898 2110
1899On systems that do not implement C<munlockall>, this function returns 2111On systems that do not implement C<munlockall>, this function returns
1900ENOSYS, otherwise the return value of C<munlockall>. 2112ENOSYS, otherwise the return value of C<munlockall>.
2113
2114=item IO::AIO::splice $r_fh, $r_off, $w_fh, $w_off, $length, $flags
2115
2116Calls the GNU/Linux C<splice(2)> syscall, if available. If C<$r_off> or
2117C<$w_off> are C<undef>, then C<NULL> is passed for these, otherwise they
2118should be the file offset.
2119
2120C<$r_fh> and C<$w_fh> should not refer to the same file, as splice might
2121silently corrupt the data in this case.
2122
2123The following symbol flag values are available: C<IO::AIO::SPLICE_F_MOVE>,
2124C<IO::AIO::SPLICE_F_NONBLOCK>, C<IO::AIO::SPLICE_F_MORE> and
2125C<IO::AIO::SPLICE_F_GIFT>.
2126
2127See the C<splice(2)> manpage for details.
2128
2129=item IO::AIO::tee $r_fh, $w_fh, $length, $flags
2130
2131Calls the GNU/Linux C<tee(2)> syscall, see its manpage and the
2132description for C<IO::AIO::splice> above for details.
2133
2134=item $actual_size = IO::AIO::pipesize $r_fh[, $new_size]
2135
2136Attempts to query or change the pipe buffer size. Obviously works only
2137on pipes, and currently works only on GNU/Linux systems, and fails with
2138C<-1>/C<ENOSYS> everywhere else. If anybody knows how to influence pipe buffer
2139size on other systems, drop me a note.
2140
2141=item ($rfh, $wfh) = IO::AIO::pipe2 [$flags]
2142
2143This is a direct interface to the Linux L<pipe2(2)> system call. If
2144C<$flags> is missing or C<0>, then this should be the same as a call to
2145perl's built-in C<pipe> function and create a new pipe, and works on
2146systems that lack the pipe2 syscall. On win32, this case invokes C<_pipe
2147(..., 4096, O_BINARY)>.
2148
2149If C<$flags> is non-zero, it tries to invoke the pipe2 system call with
2150the given flags (Linux 2.6.27, glibc 2.9).
2151
2152On success, the read and write file handles are returned.
2153
2154On error, nothing will be returned. If the pipe2 syscall is missing and
2155C<$flags> is non-zero, fails with C<ENOSYS>.
2156
2157Please refer to L<pipe2(2)> for more info on the C<$flags>, but at the
2158time of this writing, C<IO::AIO::O_CLOEXEC>, C<IO::AIO::O_NONBLOCK> and
2159C<IO::AIO::O_DIRECT> (Linux 3.4, for packet-based pipes) were supported.
1901 2160
1902=back 2161=back
1903 2162
1904=cut 2163=cut
1905 2164

Diff Legend

Removed lines
+ Added lines
< Changed lines
> Changed lines