[ViewVC] Diff of: cvs/IO-AIO/AIO.pm

Comparing IO-AIO/AIO.pm (file contents):
Revision 1.217 by root, Sun Oct 9 22:25:00 2011 UTC vs.
Revision 1.257 by root, Mon Jan 18 11:53:09 2016 UTC

…		…
68	=head2 EXAMPLE	68	=head2 EXAMPLE
69		69
70	This is a simple example that uses the EV module and loads	70	This is a simple example that uses the EV module and loads
71	F</etc/passwd> asynchronously:	71	F</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
112	Every C<aio_*> function creates a request. which is a C data structure not	111	Every C<aio_*> function creates a request. which is a C data structure not
113	directly visible to Perl.	112	directly visible to Perl.
…		…
168	use common::sense;	167	use common::sense;
169		168
170	use base 'Exporter';	169	use base 'Exporter';
171		170
172	BEGIN {	171	BEGIN {
173	our $VERSION = '4.11';	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
207	This section simply lists the prototypes of the most important functions	206	This section simply lists the prototypes most of the functions for
208	for quick reference. See the following sections for function-by-function	207	quick reference. See the following sections for function-by-function
209	documentation.	208	documentation.
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)
…		…
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, $length = undef
279	IO::AIO::munlockall	283	IO::AIO::munlockall
280		284
281	=head2 AIO REQUEST FUNCTIONS	285	=head2 API NOTES
282		286
283	All the C<aio_*> calls are more or less thin wrappers around the syscall	287	All the C<aio_*> calls are more or less thin wrappers around the syscall
284	with the same name (sans C<aio_>). The arguments are similar or identical,	288	with the same name (sans C<aio_>). The arguments are similar or identical,
285	and they all accept an additional (and optional) C<$callback> argument	289	and they all accept an additional (and optional) C<$callback> argument
286	which must be a code reference. This code reference will be called after	290	which must be a code reference. This code reference will be called after
…		…
317	correct contents.	321	correct contents.
318		322
319	This works, btw. independent of the internal UTF-8 bit, which IO::AIO	323	This works, btw. independent of the internal UTF-8 bit, which IO::AIO
320	handles correctly whether it is set or not.	324	handles 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
326	Returns the priority value that would be used for the next request and, if	332	Returns 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
359	Asynchronously open or create a file and call the callback with a newly	365	Asynchronously open or create a file and call the callback with a newly
360	created filehandle for the file.	366	created filehandle for the file (or C<undef> in case of an error).
361		367
362	The pathname passed to C<aio_open> must be absolute. See API NOTES, above,	368	The pathname passed to C<aio_open> must be absolute. See API NOTES, above,
363	for an explanation.	369	for an explanation.
364		370
365	The C<$flags> argument is a bitmask. See the C<Fcntl> module for a	371	The C<$flags> argument is a bitmask. See the C<Fcntl> module for a
…		…
388	following POSIX and non-POSIX constants are available (missing ones on	394	following POSIX and non-POSIX constants are available (missing ones on
389	your system are, as usual, C<0>):	395	your system are, as usual, C<0>):
390		396
391	C<O_ASYNC>, C<O_DIRECT>, C<O_NOATIME>, C<O_CLOEXEC>, C<O_NOCTTY>, C<O_NOFOLLOW>,	397	C<O_ASYNC>, C<O_DIRECT>, C<O_NOATIME>, C<O_CLOEXEC>, C<O_NOCTTY>, C<O_NOFOLLOW>,
392	C<O_NONBLOCK>, C<O_EXEC>, C<O_SEARCH>, C<O_DIRECTORY>, C<O_DSYNC>,	398	C<O_NONBLOCK>, C<O_EXEC>, C<O_SEARCH>, C<O_DIRECTORY>, C<O_DSYNC>,
393	C<O_RSYNC>, C<O_SYNC> and C<O_TTY_INIT>.	399	C<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
398	Asynchronously close a file and call the callback with the result	404	Asynchronously close a file and call the callback with the result
…		…
407		413
408	Or in other words: the file descriptor will be closed, but it will not be	414	Or in other words: the file descriptor will be closed, but it will not be
409	free for reuse until the perl filehandle is closed.	415	free 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
		421	Seeks the filehandle to the new C<$offset>, similarly to perl's
		422	C<sysseek>. The C<$whence> can use the traditional values (C<0> for
		423	C<IO::AIO::SEEK_SET>, C<1> for C<IO::AIO::SEEK_CUR> or C<2> for
		424	C<IO::AIO::SEEK_END>).
		425
		426	The resulting absolute offset will be passed to the callback, or C<-1> in
		427	case of an error.
		428
		429	In theory, the C<$whence> constants could be different than the
		430	corresponding values from L<Fcntl>, but perl guarantees they are the same,
		431	so don't panic.
		432
		433	As a GNU/Linux (and maybe Solaris) extension, also the constants
		434	C<IO::AIO::SEEK_DATA> and C<IO::AIO::SEEK_HOLE> are available, if they
		435	could be found. No guarantees about suitability for use in C<aio_seek> or
		436	Perl'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
		607	Here is a (likely partial - send me updates!) list of fsid values used by
		608	Linux - 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
584	Works like perl's C<utime> function (including the special case of $atime	694	Works like perl's C<utime> function (including the special case of $atime
585	and $mtime being undef). Fractional times are supported if the underlying	695	and $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
615	Works like truncate(2) or ftruncate(2).	725	Works like truncate(2) or ftruncate(2).
616		726
617		727
		728	=item aio_allocate $fh, $mode, $offset, $len, $callback->($status)
		729
		730	Allocates or frees disk space according to the C<$mode> argument. See the
		731	linux C<fallocate> documentation for details.
		732
		733	C<$mode> is usually C<0> or C<IO::AIO::FALLOC_FL_KEEP_SIZE> to allocate
		734	space, or C<IO::AIO::FALLOC_FL_PUNCH_HOLE \| IO::AIO::FALLOC_FL_KEEP_SIZE>,
		735	to deallocate a file range.
		736
		737	IO::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
		739	your L<fallocate(2)> manpage).
		740
		741	The file system block size used by C<fallocate> is presumably the
		742	C<f_bsize> returned by C<statvfs>.
		743
		744	If C<fallocate> isn't available or cannot be emulated (currently no
		745	emulation 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
620	Works like perl's C<chmod> function.	750	Works 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
663	Asynchronously make the path absolute and resolve any symlinks in	793	Asynchronously make the path absolute and resolve any symlinks in
664	C<$path>. The resulting path only consists of directories (Same as	794	C<$path>. The resulting path only consists of directories (same as
665	L<Cwd::realpath>).	795	L<Cwd::realpath>).
666		796
667	This request can be used to get the absolute path of the current working	797	This request can be used to get the absolute path of the current working
668	directory by passing it a path of F<.> (a single dot).	798	directory 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
673	Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as	803	Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as
674	rename(2) and call the callback with the result code.	804	rename(2) and call the callback with the result code.
		805
		806	On systems that support the AIO::WD working directory abstraction
		807	natively, the case C<[$wd, "."]> as C<$srcpath> is specialcased - instead
		808	of 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
679	Asynchronously mkdir (create) a directory and call the callback with	813	Asynchronously 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
686	Asynchronously rmdir (delete) a directory and call the callback with the	820	Asynchronously rmdir (delete) a directory and call the callback with the
687	result code.	821	result code.
		822
		823	On systems that support the AIO::WD working directory abstraction
		824	natively, the case C<[$wd, "."]> is specialcased - instead of failing,
		825	C<rmdir> is called on the absolute path of C<$wd>.
688		826
689		827
690	=item aio_readdir $pathname, $callback->($entries)	828	=item aio_readdir $pathname, $callback->($entries)
691		829
692	Unlike the POSIX call of the same name, C<aio_readdir> reads an entire	830	Unlike 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
1061	Delete a directory tree starting (and including) C<$path>, return the	1199	Delete a directory tree starting (and including) C<$path>, return the
1062	status of the final C<rmdir> only. This is a composite request that	1200	status of the final C<rmdir> only. This is a composite request that
1063	uses C<aio_scandir> to recurse into and rmdir directories, and unlink	1201	uses C<aio_scandir> to recurse into and rmdir directories, and unlink
1064	everything else.	1202	everything else.
1065		1203
1066	=cut	1204	=cut
1067		1205
…		…
1187		1325
1188	This is a rather advanced IO::AIO call, which works best on mmap(2)ed	1326	This is a rather advanced IO::AIO call, which works best on mmap(2)ed
1189	scalars.	1327	scalars.
1190		1328
1191	It touches (reads or writes) all memory pages in the specified	1329	It touches (reads or writes) all memory pages in the specified
1192	range inside the scalar. All caveats and parameters are the same	1330	range inside the scalar. All caveats and parameters are the same
1193	as for C<aio_msync>, above, except for flags, which must be either	1331	as for C<aio_msync>, above, except for flags, which must be either
1194	C<0> (which reads all pages and ensures they are instantiated) or	1332	C<0> (which reads all pages and ensures they are instantiated) or
1195	C<IO::AIO::MT_MODIFY>, which modifies the memory page s(by reading and	1333	C<IO::AIO::MT_MODIFY>, which modifies the memory pages (by reading and
1196	writing an octet from it, which dirties the page).	1334	writing 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
1200	This is a rather advanced IO::AIO call, which works best on mmap(2)ed	1338	This is a rather advanced IO::AIO call, which works best on mmap(2)ed
…		…
1231	documented under L<MISCELLANEOUS FUNCTIONS>.	1369	documented under L<MISCELLANEOUS FUNCTIONS>.
1232		1370
1233	Example: asynchronously lock all current and future pages into memory.	1371	Example: 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, $cb->(\@extents)
		1376
		1377	Queries the extents of the given file (by calling the Linux C<FIEMAP>
		1378	ioctl, see L<http://cvs.schmorp.de/IO-AIO/doc/fiemap.txt> for details). If
		1379	the ioctl is not available on your OS, then this request will fail with
		1380	C<ENOSYS>.
		1381
		1382	C<$start> is the starting offset to query extents for, C<$length> is the
		1383	size of the range to query - if it is C<undef>, then the whole file will
		1384	be queried.
		1385
		1386	C<$flags> is a combination of flags (C<IO::AIO::FIEMAP_FLAG_SYNC> or
		1387	C<IO::AIO::FIEMAP_FLAG_XATTR> - C<IO::AIO::FIEMAP_FLAGS_COMPAT> is also
		1388	exported), and is normally C<0> or C<IO::AIO::FIEMAP_FLAG_SYNC> to query
		1389	the data portion.
		1390
		1391	C<$count> is the maximum number of extent records to return. If it is
		1392	C<undef>, then IO::AIO queries all extents of the range. As a very special
		1393	case, if it is C<0>, then the callback receives the number of extents
		1394	instead of the extents themselves (which is unreliable, see below).
		1395
		1396	If an error occurs, the callback receives no arguments. The special
		1397	C<errno> value C<IO::AIO::EBADR> is available to test for flag errors.
		1398
		1399	Otherwise, the callback receives an array reference with extent
		1400	structures. Each extent structure is an array reference itself, with the
		1401	following members:
		1402
		1403	[$logical, $physical, $length, $flags]
		1404
		1405	Flags is any combination of the following flag values (typically either C<0>
		1406	or C<IO::AIO::FIEMAP_EXTENT_LAST> (1)):
		1407
		1408	C<IO::AIO::FIEMAP_EXTENT_LAST>, C<IO::AIO::FIEMAP_EXTENT_UNKNOWN>,
		1409	C<IO::AIO::FIEMAP_EXTENT_DELALLOC>, C<IO::AIO::FIEMAP_EXTENT_ENCODED>,
		1410	C<IO::AIO::FIEMAP_EXTENT_DATA_ENCRYPTED>, C<IO::AIO::FIEMAP_EXTENT_NOT_ALIGNED>,
		1411	C<IO::AIO::FIEMAP_EXTENT_DATA_INLINE>, C<IO::AIO::FIEMAP_EXTENT_DATA_TAIL>,
		1412	C<IO::AIO::FIEMAP_EXTENT_UNWRITTEN>, C<IO::AIO::FIEMAP_EXTENT_MERGED> or
		1413	C<IO::AIO::FIEMAP_EXTENT_SHARED>.
		1414
		1415	At the time of this writing (Linux 3.2), this requets is unreliable unless
		1416	C<$count> is C<undef>, as the kernel has all sorts of bugs preventing
		1417	it to return all extents of a range for files with large number of
		1418	extents. The code works around all these issues if C<$count> is undef.
1236		1419
1237	=item aio_group $callback->(...)	1420	=item aio_group $callback->(...)
1238		1421
1239	This is a very special aio request: Instead of doing something, it is a	1422	This is a very special aio request: Instead of doing something, it is a
1240	container for other aio requests, which is useful if you want to bundle	1423	container for other aio requests, which is useful if you want to bundle
…		…
1324	aio_stat [$etcdir, "passwd"], sub {	1507	aio_stat [$etcdir, "passwd"], sub {
1325	# yay	1508	# yay
1326	};	1509	};
1327	};	1510	};
1328		1511
1329	That C<aio_wd> is a request and not a normal function shows that creating	1512	The fact that C<aio_wd> is a request and not a normal function shows that
1330	an IO::AIO::WD object is itself a potentially blocking operation, which is	1513	creating an IO::AIO::WD object is itself a potentially blocking operation,
1331	why it is done asynchronously.	1514	which is why it is done asynchronously.
1332		1515
1333	To stat the directory obtained with C<aio_wd> above, one could write	1516	To stat the directory obtained with C<aio_wd> above, one could write
1334	either of the following three request calls:	1517	either of the following three request calls:
1335		1518
1336	aio_lstat "/etc" , sub { ... # pathname as normal string	1519	aio_lstat "/etc" , sub { ... # pathname as normal string
…		…
1356	will still point to the original directory. Most functions accepting a	1539	will still point to the original directory. Most functions accepting a
1357	pathname will use the directory fd on newer systems, and the string on	1540	pathname will use the directory fd on newer systems, and the string on
1358	older systems. Some functions (such as realpath) will always rely on the	1541	older systems. Some functions (such as realpath) will always rely on the
1359	string form of the pathname.	1542	string form of the pathname.
1360		1543
1361	So this fucntionality is mainly useful to get some protection against	1544	So this functionality is mainly useful to get some protection against
1362	C<chdir>, to easily get an absolute path out of a relative path for future	1545	C<chdir>, to easily get an absolute path out of a relative path for future
1363	reference, and to speed up doing many operations in the same directory	1546	reference, and to speed up doing many operations in the same directory
1364	(e.g. when stat'ing all files in a directory).	1547	(e.g. when stat'ing all files in a directory).
1365		1548
1366	The following functions implement this working directory abstraction:	1549	The following functions implement this working directory abstraction:
…		…
1379	passing C<undef> as working directory component of a pathname fails the	1562	passing C<undef> as working directory component of a pathname fails the
1380	request with C<ENOENT>, there is often no need for error checking in the	1563	request with C<ENOENT>, there is often no need for error checking in the
1381	C<aio_wd> callback, as future requests using the value will fail in the	1564	C<aio_wd> callback, as future requests using the value will fail in the
1382	expected way.	1565	expected way.
1383		1566
1384	If this call isn't available because your OS lacks it or it couldn't be
1385	detected, it will be emulated by calling C<fsync> instead.
1386
1387	=item IO::AIO::CWD	1567	=item IO::AIO::CWD
1388		1568
1389	This is a compiletime constant (object) that represents the process	1569	This is a compiletime constant (object) that represents the process
1390	current working directory.	1570	current working directory.
1391		1571
1392	Specifying this object as working directory object for a pathname is as	1572	Specifying this object as working directory object for a pathname is as if
1393	if the pathname would be specified directly, without a directory object,	1573	the pathname would be specified directly, without a directory object. For
1394	e.g., these calls are functionally identical:	1574	example, these calls are functionally identical:
1395		1575
1396	aio_stat "somefile", sub { ... };	1576	aio_stat "somefile", sub { ... };
1397	aio_stat [IO::AIO::CWD, "somefile"], sub { ... };	1577	aio_stat [IO::AIO::CWD, "somefile"], sub { ... };
1398		1578
1399	=back	1579	=back
1400		1580
		1581	To recover the path associated with an IO::AIO::WD object, you can use
		1582	C<aio_realpath>:
		1583
		1584	aio_realpath $wd, sub {
		1585	warn "path is $_[0]\n";
		1586	};
		1587
		1588	Currently, C<aio_statvfs> always, and C<aio_rename> and C<aio_rmdir>
		1589	sometimes, fall back to using an absolue path.
1401		1590
1402	=head2 IO::AIO::REQ CLASS	1591	=head2 IO::AIO::REQ CLASS
1403		1592
1404	All non-aggregate C<aio_*> functions return an object of this class when	1593	All non-aggregate C<aio_*> functions return an object of this class when
1405	called in non-void context.	1594	called in non-void context.
…		…
1583		1772
1584	See C<poll_cb> for an example.	1773	See C<poll_cb> for an example.
1585		1774
1586	=item IO::AIO::poll_cb	1775	=item IO::AIO::poll_cb
1587		1776
1588	Process some outstanding events on the result pipe. You have to call	1777	Process some requests that have reached the result phase (i.e. they have
		1778	been executed but the results are not yet reported). You have to call
		1779	this "regularly" to finish outstanding requests.
		1780
1589	this regularly. Returns C<0> if all events could be processed (or there	1781	Returns C<0> if all events could be processed (or there were no
1590	were no events to process), or C<-1> if it returned earlier for whatever	1782	events to process), or C<-1> if it returned earlier for whatever
1591	reason. Returns immediately when no events are outstanding. The amount of	1783	reason. Returns immediately when no events are outstanding. The amount
1592	events processed depends on the settings of C<IO::AIO::max_poll_req> and	1784	of events processed depends on the settings of C<IO::AIO::max_poll_req>,
1593	C<IO::AIO::max_poll_time>.	1785	C<IO::AIO::max_poll_time> and C<IO::AIO::max_outstanding>.
1594		1786
1595	If not all requests were processed for whatever reason, the filehandle	1787	If not all requests were processed for whatever reason, the poll file
1596	will still be ready when C<poll_cb> returns, so normally you don't have to	1788	descriptor will still be ready when C<poll_cb> returns, so normally you
1597	do anything special to have it called later.	1789	don't have to do anything special to have it called later.
1598		1790
1599	Apart from calling C<IO::AIO::poll_cb> when the event filehandle becomes	1791	Apart from calling C<IO::AIO::poll_cb> when the event filehandle becomes
1600	ready, it can be beneficial to call this function from loops which submit	1792	ready, it can be beneficial to call this function from loops which submit
1601	a lot of requests, to make sure the results get processed when they become	1793	a lot of requests, to make sure the results get processed when they become
1602	available and not just when the loop is finished and the event loop takes	1794	available and not just when the loop is finished and the event loop takes
…		…
1611	poll => 'r', async => 1,	1803	poll => 'r', async => 1,
1612	cb => \&IO::AIO::poll_cb);	1804	cb => \&IO::AIO::poll_cb);
1613		1805
1614	=item IO::AIO::poll_wait	1806	=item IO::AIO::poll_wait
1615		1807
1616	If there are any outstanding requests and none of them in the result	1808	Wait until either at least one request is in the result phase or no
1617	phase, wait till the result filehandle becomes ready for reading (simply	1809	requests are outstanding anymore.
1618	does a C<select> on the filehandle. This is useful if you want to	1810
1619	synchronously wait for some requests to finish).	1811	This is useful if you want to synchronously wait for some requests to
		1812	become ready, without actually handling them.
1620		1813
1621	See C<nreqs> for an example.	1814	See C<nreqs> for an example.
1622		1815
1623	=item IO::AIO::poll	1816	=item IO::AIO::poll
1624		1817
…		…
1745		1938
1746	This is a very bad function to use in interactive programs because it	1939	This is a very bad function to use in interactive programs because it
1747	blocks, and a bad way to reduce concurrency because it is inexact: Better	1940	blocks, and a bad way to reduce concurrency because it is inexact: Better
1748	use an C<aio_group> together with a feed callback.	1941	use an C<aio_group> together with a feed callback.
1749		1942
1750	It's main use is in scripts without an event loop - when you want to stat	1943	Its main use is in scripts without an event loop - when you want to stat
1751	a lot of files, you can write somehting like this:	1944	a lot of files, you can write somehting like this:
1752		1945
1753	IO::AIO::max_outstanding 32;	1946	IO::AIO::max_outstanding 32;
1754		1947
1755	for my $path (...) {	1948	for my $path (...) {
…		…
1795		1988
1796	=back	1989	=back
1797		1990
1798	=head3 MISCELLANEOUS FUNCTIONS	1991	=head3 MISCELLANEOUS FUNCTIONS
1799		1992
1800	IO::AIO implements some functions that might be useful, but are not	1993	IO::AIO implements some functions that are useful when you want to use
1801	asynchronous.	1994	some "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_*>
		1996	counterpart.
1802		1997
1803	=over 4	1998	=over 4
1804		1999
1805	=item IO::AIO::sendfile $ofh, $ifh, $offset, $count	2000	=item IO::AIO::sendfile $ofh, $ifh, $offset, $count
1806		2001
…		…
1843	ENOSYS, otherwise the return value of C<mprotect>.	2038	ENOSYS, otherwise the return value of C<mprotect>.
1844		2039
1845	=item IO::AIO::mmap $scalar, $length, $prot, $flags, $fh[, $offset]	2040	=item IO::AIO::mmap $scalar, $length, $prot, $flags, $fh[, $offset]
1846		2041
1847	Memory-maps a file (or anonymous memory range) and attaches it to the	2042	Memory-maps a file (or anonymous memory range) and attaches it to the
1848	given C<$scalar>, which will act like a string scalar.	2043	given C<$scalar>, which will act like a string scalar. Returns true on
		2044	success, and false otherwise.
1849		2045
1850	The only operations allowed on the scalar are C<substr>/C<vec> that don't	2046	The only operations allowed on the scalar are C<substr>/C<vec> that don't
1851	change the string length, and most read-only operations such as copying it	2047	change the string length, and most read-only operations such as copying it
1852	or searching it with regexes and so on.	2048	or searching it with regexes and so on.
1853		2049
…		…
1864	filesize.	2060	filesize.
1865		2061
1866	C<$prot> is a combination of C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_EXEC>,	2062	C<$prot> is a combination of C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_EXEC>,
1867	C<IO::AIO::PROT_READ> and/or C<IO::AIO::PROT_WRITE>,	2063	C<IO::AIO::PROT_READ> and/or C<IO::AIO::PROT_WRITE>,
1868		2064
1869	C<$flags> can be a combination of C<IO::AIO::MAP_SHARED> or	2065	C<$flags> can be a combination of
1870	C<IO::AIO::MAP_PRIVATE>, or a number of system-specific flags (when	2066	C<IO::AIO::MAP_SHARED> or
1871	not available, the are defined as 0): C<IO::AIO::MAP_ANONYMOUS>	2067	C<IO::AIO::MAP_PRIVATE>,
		2068	or a number of system-specific flags (when not available, the are C<0>):
1872	(which is set to C<MAP_ANON> if your system only provides this	2069	C<IO::AIO::MAP_ANONYMOUS> (which is set to C<MAP_ANON> if your system only provides this constant),
1873	constant), C<IO::AIO::MAP_HUGETLB>, C<IO::AIO::MAP_LOCKED>,	2070	C<IO::AIO::MAP_HUGETLB>,
1874	C<IO::AIO::MAP_NORESERVE>, C<IO::AIO::MAP_POPULATE> or	2071	C<IO::AIO::MAP_LOCKED>,
		2072	C<IO::AIO::MAP_NORESERVE>,
		2073	C<IO::AIO::MAP_POPULATE>,
1875	C<IO::AIO::MAP_NONBLOCK>	2074	C<IO::AIO::MAP_NONBLOCK>,
		2075	C<IO::AIO::MAP_FIXED>,
		2076	C<IO::AIO::MAP_GROWSDOWN>,
		2077	C<IO::AIO::MAP_32BIT>,
		2078	C<IO::AIO::MAP_HUGETLB> or
		2079	C<IO::AIO::MAP_STACK>.
1876		2080
1877	If C<$fh> is C<undef>, then a file descriptor of C<-1> is passed.	2081	If C<$fh> is C<undef>, then a file descriptor of C<-1> is passed.
1878		2082
1879	C<$offset> is the offset from the start of the file - it generally must be	2083	C<$offset> is the offset from the start of the file - it generally must be
1880	a multiple of C<IO::AIO::PAGESIZE> and defaults to C<0>.	2084	a multiple of C<IO::AIO::PAGESIZE> and defaults to C<0>.
…		…
1905		2109
1906	Calls the C<munlockall> function.	2110	Calls the C<munlockall> function.
1907		2111
1908	On systems that do not implement C<munlockall>, this function returns	2112	On systems that do not implement C<munlockall>, this function returns
1909	ENOSYS, otherwise the return value of C<munlockall>.	2113	ENOSYS, otherwise the return value of C<munlockall>.
		2114
		2115	=item IO::AIO::splice $r_fh, $r_off, $w_fh, $w_off, $length, $flags
		2116
		2117	Calls the GNU/Linux C<splice(2)> syscall, if available. If C<$r_off> or
		2118	C<$w_off> are C<undef>, then C<NULL> is passed for these, otherwise they
		2119	should be the file offset.
		2120
		2121	C<$r_fh> and C<$w_fh> should not refer to the same file, as splice might
		2122	silently corrupt the data in this case.
		2123
		2124	The following symbol flag values are available: C<IO::AIO::SPLICE_F_MOVE>,
		2125	C<IO::AIO::SPLICE_F_NONBLOCK>, C<IO::AIO::SPLICE_F_MORE> and
		2126	C<IO::AIO::SPLICE_F_GIFT>.
		2127
		2128	See the C<splice(2)> manpage for details.
		2129
		2130	=item IO::AIO::tee $r_fh, $w_fh, $length, $flags
		2131
		2132	Calls the GNU/Linux C<tee(2)> syscall, see its manpage and the
		2133	description for C<IO::AIO::splice> above for details.
		2134
		2135	=item $actual_size = IO::AIO::pipesize $r_fh[, $new_size]
		2136
		2137	Attempts to query or change the pipe buffer size. Obviously works only
		2138	on pipes, and currently works only on GNU/Linux systems, and fails with
		2139	C<-1>/C<ENOSYS> everywhere else. If anybody knows how to influence pipe buffer
		2140	size on other systems, drop me a note.
		2141
		2142	=item ($rfh, $wfh) = IO::AIO::pipe2 [$flags]
		2143
		2144	This is a direct interface to the Linux L<pipe2(2)> system call. If
		2145	C<$flags> is missing or C<0>, then this should be the same as a call to
		2146	perl's built-in C<pipe> function and create a new pipe, and works on
		2147	systems that lack the pipe2 syscall. On win32, this case invokes C<_pipe
		2148	(..., 4096, O_BINARY)>.
		2149
		2150	If C<$flags> is non-zero, it tries to invoke the pipe2 system call with
		2151	the given flags (Linux 2.6.27, glibc 2.9).
		2152
		2153	On success, the read and write file handles are returned.
		2154
		2155	On error, nothing will be returned. If the pipe2 syscall is missing and
		2156	C<$flags> is non-zero, fails with C<ENOSYS>.
		2157
		2158	Please refer to L<pipe2(2)> for more info on the C<$flags>, but at the
		2159	time of this writing, C<IO::AIO::O_CLOEXEC>, C<IO::AIO::O_NONBLOCK> and
		2160	C<IO::AIO::O_DIRECT> (Linux 3.4, for packet-based pipes) were supported.
1910		2161
1911	=back	2162	=back
1912		2163
1913	=cut	2164	=cut
1914		2165

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Comparing IO-AIO/AIO.pm (file contents): Revision 1.217 by root, Sun Oct 9 22:25:00 2011 UTC vs. Revision 1.257 by root, Mon Jan 18 11:53:09 2016 UTC

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Comparing IO-AIO/AIO.pm (file contents):
Revision 1.217 by root, Sun Oct 9 22:25:00 2011 UTC vs.
Revision 1.257 by root, Mon Jan 18 11:53:09 2016 UTC