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

Comparing IO-AIO/AIO.pm (file contents):
Revision 1.229 by root, Wed Jul 25 16:32:30 2012 UTC vs.
Revision 1.270 by root, Fri Jun 23 03:23:19 2017 UTC

…		…
1	=head1 NAME	1	=head1 NAME
2		2
3	IO::AIO - Asynchronous Input/Output	3	IO::AIO - Asynchronous/Advanced Input/Output
4		4
5	=head1 SYNOPSIS	5	=head1 SYNOPSIS
6		6
7	use IO::AIO;	7	use IO::AIO;
8		8
58	not well-supported or restricted (GNU/Linux doesn't allow them on normal	58	not well-supported or restricted (GNU/Linux doesn't allow them on normal
59	files currently, for example), and they would only support aio_read and	59	files currently, for example), and they would only support aio_read and
60	aio_write, so the remaining functionality would have to be implemented	60	aio_write, so the remaining functionality would have to be implemented
61	using threads anyway.	61	using threads anyway.
62		62
		63	In addition to asynchronous I/O, this module also exports some rather
		64	arcane interfaces, such as C<madvise> or linux's C<splice> system call,
		65	which is why the C<A> in C<AIO> can also mean I<advanced>.
		66
63	Although the module will work in the presence of other (Perl-) threads,	67	Although the module will work in the presence of other (Perl-) threads,
64	it is currently not reentrant in any way, so use appropriate locking	68	it is currently not reentrant in any way, so use appropriate locking
65	yourself, always call C<poll_cb> from within the same thread, or never	69	yourself, always call C<poll_cb> from within the same thread, or never
66	call C<poll_cb> (or other C<aio_> functions) recursively.	70	call C<poll_cb> (or other C<aio_> functions) recursively.
67		71
68	=head2 EXAMPLE	72	=head2 EXAMPLE
69		73
70	This is a simple example that uses the EV module and loads	74	This is a simple example that uses the EV module and loads
71	F</etc/passwd> asynchronously:	75	F</etc/passwd> asynchronously:
72		76
73	use Fcntl;
74	use EV;	77	use EV;
75	use IO::AIO;	78	use IO::AIO;
76		79
77	# register the IO::AIO callback with EV	80	# register the IO::AIO callback with EV
78	my $aio_w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb;	81	my $aio_w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb;
…		…
95		98
96	# file contents now in $contents	99	# file contents now in $contents
97	print $contents;	100	print $contents;
98		101
99	# exit event loop and program	102	# exit event loop and program
100	EV::unloop;	103	EV::break;
101	};	104	};
102	};	105	};
103		106
104	# possibly queue up other requests, or open GUI windows,	107	# possibly queue up other requests, or open GUI windows,
105	# check for sockets etc. etc.	108	# check for sockets etc. etc.
106		109
107	# process events as long as there are some:	110	# process events as long as there are some:
108	EV::loop;	111	EV::run;
109		112
110	=head1 REQUEST ANATOMY AND LIFETIME	113	=head1 REQUEST ANATOMY AND LIFETIME
111		114
112	Every C<aio_*> function creates a request. which is a C data structure not	115	Every C<aio_*> function creates a request. which is a C data structure not
113	directly visible to Perl.	116	directly visible to Perl.
…		…
168	use common::sense;	171	use common::sense;
169		172
170	use base 'Exporter';	173	use base 'Exporter';
171		174
172	BEGIN {	175	BEGIN {
173	our $VERSION = '4.15';	176	our $VERSION = 4.35;
174		177
175	our @AIO_REQ = qw(aio_sendfile aio_seek aio_read aio_write aio_open aio_close	178	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	179	aio_stat aio_lstat aio_unlink aio_rmdir aio_readdir aio_readdirx
177	aio_scandir aio_symlink aio_readlink aio_realpath aio_sync	180	aio_scandir aio_symlink aio_readlink aio_realpath aio_fcntl aio_ioctl
178	aio_fsync aio_syncfs aio_fdatasync aio_sync_file_range aio_fallocate	181	aio_sync aio_fsync aio_syncfs aio_fdatasync aio_sync_file_range
179	aio_pathsync aio_readahead aio_fiemap	182	aio_pathsync aio_readahead aio_fiemap aio_allocate
180	aio_rename aio_link aio_move aio_copy aio_group	183	aio_rename aio_rename2 aio_link aio_move aio_copy aio_group
181	aio_nop aio_mknod aio_load aio_rmtree aio_mkdir aio_chown	184	aio_nop aio_mknod aio_load aio_rmtree aio_mkdir aio_chown
182	aio_chmod aio_utime aio_truncate	185	aio_chmod aio_utime aio_truncate
183	aio_msync aio_mtouch aio_mlock aio_mlockall	186	aio_msync aio_mtouch aio_mlock aio_mlockall
184	aio_statvfs	187	aio_statvfs
185	aio_wd);	188	aio_wd);
…		…
202		205
203	=head1 FUNCTIONS	206	=head1 FUNCTIONS
204		207
205	=head2 QUICK OVERVIEW	208	=head2 QUICK OVERVIEW
206		209
207	This section simply lists the prototypes of the most important functions	210	This section simply lists the prototypes most of the functions for
208	for quick reference. See the following sections for function-by-function	211	quick reference. See the following sections for function-by-function
209	documentation.	212	documentation.
210		213
211	aio_wd $pathname, $callback->($wd)	214	aio_wd $pathname, $callback->($wd)
212	aio_open $pathname, $flags, $mode, $callback->($fh)	215	aio_open $pathname, $flags, $mode, $callback->($fh)
213	aio_close $fh, $callback->($status)	216	aio_close $fh, $callback->($status)
…		…
222	aio_utime $fh_or_path, $atime, $mtime, $callback->($status)	225	aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
223	aio_chown $fh_or_path, $uid, $gid, $callback->($status)	226	aio_chown $fh_or_path, $uid, $gid, $callback->($status)
224	aio_chmod $fh_or_path, $mode, $callback->($status)	227	aio_chmod $fh_or_path, $mode, $callback->($status)
225	aio_truncate $fh_or_path, $offset, $callback->($status)	228	aio_truncate $fh_or_path, $offset, $callback->($status)
226	aio_allocate $fh, $mode, $offset, $len, $callback->($status)	229	aio_allocate $fh, $mode, $offset, $len, $callback->($status)
		230	aio_fiemap $fh, $start, $length, $flags, $count, $cb->(\@extents)
227	aio_unlink $pathname, $callback->($status)	231	aio_unlink $pathname, $callback->($status)
228	aio_mknod $pathname, $mode, $dev, $callback->($status)	232	aio_mknod $pathname, $mode, $dev, $callback->($status)
229	aio_link $srcpath, $dstpath, $callback->($status)	233	aio_link $srcpath, $dstpath, $callback->($status)
230	aio_symlink $srcpath, $dstpath, $callback->($status)	234	aio_symlink $srcpath, $dstpath, $callback->($status)
231	aio_readlink $pathname, $callback->($link)	235	aio_readlink $pathname, $callback->($link)
232	aio_realpath $pathname, $callback->($link)	236	aio_realpath $pathname, $callback->($path)
233	aio_rename $srcpath, $dstpath, $callback->($status)	237	aio_rename $srcpath, $dstpath, $callback->($status)
		238	aio_rename2 $srcpath, $dstpath, $flags, $callback->($status)
234	aio_mkdir $pathname, $mode, $callback->($status)	239	aio_mkdir $pathname, $mode, $callback->($status)
235	aio_rmdir $pathname, $callback->($status)	240	aio_rmdir $pathname, $callback->($status)
236	aio_readdir $pathname, $callback->($entries)	241	aio_readdir $pathname, $callback->($entries)
237	aio_readdirx $pathname, $flags, $callback->($entries, $flags)	242	aio_readdirx $pathname, $flags, $callback->($entries, $flags)
238	IO::AIO::READDIR_DENTS IO::AIO::READDIR_DIRS_FIRST	243	IO::AIO::READDIR_DENTS IO::AIO::READDIR_DIRS_FIRST
…		…
240	aio_scandir $pathname, $maxreq, $callback->($dirs, $nondirs)	245	aio_scandir $pathname, $maxreq, $callback->($dirs, $nondirs)
241	aio_load $pathname, $data, $callback->($status)	246	aio_load $pathname, $data, $callback->($status)
242	aio_copy $srcpath, $dstpath, $callback->($status)	247	aio_copy $srcpath, $dstpath, $callback->($status)
243	aio_move $srcpath, $dstpath, $callback->($status)	248	aio_move $srcpath, $dstpath, $callback->($status)
244	aio_rmtree $pathname, $callback->($status)	249	aio_rmtree $pathname, $callback->($status)
		250	aio_fcntl $fh, $cmd, $arg, $callback->($status)
		251	aio_ioctl $fh, $request, $buf, $callback->($status)
245	aio_sync $callback->($status)	252	aio_sync $callback->($status)
246	aio_syncfs $fh, $callback->($status)	253	aio_syncfs $fh, $callback->($status)
247	aio_fsync $fh, $callback->($status)	254	aio_fsync $fh, $callback->($status)
248	aio_fdatasync $fh, $callback->($status)	255	aio_fdatasync $fh, $callback->($status)
249	aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status)	256	aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status)
250	aio_pathsync $pathname, $callback->($status)	257	aio_pathsync $pathname, $callback->($status)
251	aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)	258	aio_msync $scalar, $offset = 0, $length = undef, flags = MS_SYNC, $callback->($status)
252	aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)	259	aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
253	aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status)	260	aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status)
254	aio_mlockall $flags, $callback->($status)	261	aio_mlockall $flags, $callback->($status)
255	aio_group $callback->(...)	262	aio_group $callback->(...)
256	aio_nop $callback->()	263	aio_nop $callback->()
…		…
361		368
362		369
363	=item aio_open $pathname, $flags, $mode, $callback->($fh)	370	=item aio_open $pathname, $flags, $mode, $callback->($fh)
364		371
365	Asynchronously open or create a file and call the callback with a newly	372	Asynchronously open or create a file and call the callback with a newly
366	created filehandle for the file.	373	created filehandle for the file (or C<undef> in case of an error).
367		374
368	The pathname passed to C<aio_open> must be absolute. See API NOTES, above,	375	The pathname passed to C<aio_open> must be absolute. See API NOTES, above,
369	for an explanation.	376	for an explanation.
370		377
371	The C<$flags> argument is a bitmask. See the C<Fcntl> module for a	378	The C<$flags> argument is a bitmask. See the C<Fcntl> module for a
…		…
394	following POSIX and non-POSIX constants are available (missing ones on	401	following POSIX and non-POSIX constants are available (missing ones on
395	your system are, as usual, C<0>):	402	your system are, as usual, C<0>):
396		403
397	C<O_ASYNC>, C<O_DIRECT>, C<O_NOATIME>, C<O_CLOEXEC>, C<O_NOCTTY>, C<O_NOFOLLOW>,	404	C<O_ASYNC>, C<O_DIRECT>, C<O_NOATIME>, C<O_CLOEXEC>, C<O_NOCTTY>, C<O_NOFOLLOW>,
398	C<O_NONBLOCK>, C<O_EXEC>, C<O_SEARCH>, C<O_DIRECTORY>, C<O_DSYNC>,	405	C<O_NONBLOCK>, C<O_EXEC>, C<O_SEARCH>, C<O_DIRECTORY>, C<O_DSYNC>,
399	C<O_RSYNC>, C<O_SYNC> and C<O_TTY_INIT>.	406	C<O_RSYNC>, C<O_SYNC>, C<O_PATH>, C<O_TMPFILE>, and C<O_TTY_INIT>.
400		407
401		408
402	=item aio_close $fh, $callback->($status)	409	=item aio_close $fh, $callback->($status)
403		410
404	Asynchronously close a file and call the callback with the result	411	Asynchronously close a file and call the callback with the result
…		…
439	=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)	446	=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
440		447
441	=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)	448	=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
442		449
443	Reads or writes C<$length> bytes from or to the specified C<$fh> and	450	Reads or writes C<$length> bytes from or to the specified C<$fh> and
444	C<$offset> into the scalar given by C<$data> and offset C<$dataoffset>	451	C<$offset> into the scalar given by C<$data> and offset C<$dataoffset> and
445	and calls the callback without the actual number of bytes read (or -1 on	452	calls the callback with the actual number of bytes transferred (or -1 on
446	error, just like the syscall).	453	error, just like the syscall).
447		454
448	C<aio_read> will, like C<sysread>, shrink or grow the C<$data> scalar to	455	C<aio_read> will, like C<sysread>, shrink or grow the C<$data> scalar to
449	offset plus the actual number of bytes read.	456	offset plus the actual number of bytes read.
450		457
…		…
508	As native sendfile syscalls (as practically any non-POSIX interface hacked	515	As native sendfile syscalls (as practically any non-POSIX interface hacked
509	together in a hurry to improve benchmark numbers) tend to be rather buggy	516	together in a hurry to improve benchmark numbers) tend to be rather buggy
510	on many systems, this implementation tries to work around some known bugs	517	on many systems, this implementation tries to work around some known bugs
511	in Linux and FreeBSD kernels (probably others, too), but that might fail,	518	in Linux and FreeBSD kernels (probably others, too), but that might fail,
512	so you really really should check the return value of C<aio_sendfile> -	519	so you really really should check the return value of C<aio_sendfile> -
513	fewre bytes than expected might have been transferred.	520	fewer bytes than expected might have been transferred.
514		521
515		522
516	=item aio_readahead $fh,$offset,$length, $callback->($retval)	523	=item aio_readahead $fh,$offset,$length, $callback->($retval)
517		524
518	C<aio_readahead> populates the page cache with data from a file so that	525	C<aio_readahead> populates the page cache with data from a file so that
…		…
522	whole pages, so that offset is effectively rounded down to a page boundary	529	whole pages, so that offset is effectively rounded down to a page boundary
523	and bytes are read up to the next page boundary greater than or equal to	530	and bytes are read up to the next page boundary greater than or equal to
524	(off-set+length). C<aio_readahead> does not read beyond the end of the	531	(off-set+length). C<aio_readahead> does not read beyond the end of the
525	file. The current file offset of the file is left unchanged.	532	file. The current file offset of the file is left unchanged.
526		533
527	If that syscall doesn't exist (likely if your OS isn't Linux) it will be	534	If that syscall doesn't exist (likely if your kernel isn't Linux) it will
528	emulated by simply reading the data, which would have a similar effect.	535	be emulated by simply reading the data, which would have a similar effect.
529		536
530		537
531	=item aio_stat $fh_or_path, $callback->($status)	538	=item aio_stat $fh_or_path, $callback->($status)
532		539
533	=item aio_lstat $fh, $callback->($status)	540	=item aio_lstat $fh, $callback->($status)
…		…
602	namemax => 255,	609	namemax => 255,
603	frsize => 1024,	610	frsize => 1024,
604	fsid => 1810	611	fsid => 1810
605	}	612	}
606		613
		614	Here is a (likely partial - send me updates!) list of fsid values used by
		615	Linux - it is safe to hardcode these when C<$^O> is C<linux>:
		616
		617	0x0000adf5 adfs
		618	0x0000adff affs
		619	0x5346414f afs
		620	0x09041934 anon-inode filesystem
		621	0x00000187 autofs
		622	0x42465331 befs
		623	0x1badface bfs
		624	0x42494e4d binfmt_misc
		625	0x9123683e btrfs
		626	0x0027e0eb cgroupfs
		627	0xff534d42 cifs
		628	0x73757245 coda
		629	0x012ff7b7 coh
		630	0x28cd3d45 cramfs
		631	0x453dcd28 cramfs-wend (wrong endianness)
		632	0x64626720 debugfs
		633	0x00001373 devfs
		634	0x00001cd1 devpts
		635	0x0000f15f ecryptfs
		636	0x00414a53 efs
		637	0x0000137d ext
		638	0x0000ef53 ext2/ext3/ext4
		639	0x0000ef51 ext2
		640	0xf2f52010 f2fs
		641	0x00004006 fat
		642	0x65735546 fuseblk
		643	0x65735543 fusectl
		644	0x0bad1dea futexfs
		645	0x01161970 gfs2
		646	0x47504653 gpfs
		647	0x00004244 hfs
		648	0xf995e849 hpfs
		649	0x00c0ffee hostfs
		650	0x958458f6 hugetlbfs
		651	0x2bad1dea inotifyfs
		652	0x00009660 isofs
		653	0x000072b6 jffs2
		654	0x3153464a jfs
		655	0x6b414653 k-afs
		656	0x0bd00bd0 lustre
		657	0x0000137f minix
		658	0x0000138f minix 30 char names
		659	0x00002468 minix v2
		660	0x00002478 minix v2 30 char names
		661	0x00004d5a minix v3
		662	0x19800202 mqueue
		663	0x00004d44 msdos
		664	0x0000564c novell
		665	0x00006969 nfs
		666	0x6e667364 nfsd
		667	0x00003434 nilfs
		668	0x5346544e ntfs
		669	0x00009fa1 openprom
		670	0x7461636F ocfs2
		671	0x00009fa0 proc
		672	0x6165676c pstorefs
		673	0x0000002f qnx4
		674	0x68191122 qnx6
		675	0x858458f6 ramfs
		676	0x52654973 reiserfs
		677	0x00007275 romfs
		678	0x67596969 rpc_pipefs
		679	0x73636673 securityfs
		680	0xf97cff8c selinux
		681	0x0000517b smb
		682	0x534f434b sockfs
		683	0x73717368 squashfs
		684	0x62656572 sysfs
		685	0x012ff7b6 sysv2
		686	0x012ff7b5 sysv4
		687	0x01021994 tmpfs
		688	0x15013346 udf
		689	0x00011954 ufs
		690	0x54190100 ufs byteswapped
		691	0x00009fa2 usbdevfs
		692	0x01021997 v9fs
		693	0xa501fcf5 vxfs
		694	0xabba1974 xenfs
		695	0x012ff7b4 xenix
		696	0x58465342 xfs
		697	0x012fd16d xia
607		698
608	=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status)	699	=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
609		700
610	Works like perl's C<utime> function (including the special case of $atime	701	Works like perl's C<utime> function (including the special case of $atime
611	and $mtime being undef). Fractional times are supported if the underlying	702	and $mtime being undef). Fractional times are supported if the underlying
…		…
641	Works like truncate(2) or ftruncate(2).	732	Works like truncate(2) or ftruncate(2).
642		733
643		734
644	=item aio_allocate $fh, $mode, $offset, $len, $callback->($status)	735	=item aio_allocate $fh, $mode, $offset, $len, $callback->($status)
645		736
646	Allocates or freed disk space according to the C<$mode> argument. See the	737	Allocates or frees disk space according to the C<$mode> argument. See the
647	linux C<fallocate> docuemntation for details.	738	linux C<fallocate> documentation for details.
648		739
649	C<$mode> can currently be C<0> or C<IO::AIO::FALLOC_FL_KEEP_SIZE>	740	C<$mode> is usually C<0> or C<IO::AIO::FALLOC_FL_KEEP_SIZE> to allocate
650	to allocate space, or C<IO::AIO::FALLOC_FL_PUNCH_HOLE \|	741	space, or C<IO::AIO::FALLOC_FL_PUNCH_HOLE \| IO::AIO::FALLOC_FL_KEEP_SIZE>,
651	IO::AIO::FALLOC_FL_KEEP_SIZE>, to deallocate a file range.	742	to deallocate a file range.
		743
		744	IO::AIO also supports C<FALLOC_FL_COLLAPSE_RANGE>, to remove a range
		745	(without leaving a hole) and C<FALLOC_FL_ZERO_RANGE>, to zero a range (see
		746	your L<fallocate(2)> manpage).
652		747
653	The file system block size used by C<fallocate> is presumably the	748	The file system block size used by C<fallocate> is presumably the
654	C<f_bsize> returned by C<statvfs>.	749	C<f_bsize> returned by C<statvfs>.
655		750
656	If C<fallocate> isn't available or cannot be emulated (currently no	751	If C<fallocate> isn't available or cannot be emulated (currently no
…		…
701		796
702		797
703	=item aio_realpath $pathname, $callback->($path)	798	=item aio_realpath $pathname, $callback->($path)
704		799
705	Asynchronously make the path absolute and resolve any symlinks in	800	Asynchronously make the path absolute and resolve any symlinks in
706	C<$path>. The resulting path only consists of directories (Same as	801	C<$path>. The resulting path only consists of directories (same as
707	L<Cwd::realpath>).	802	L<Cwd::realpath>).
708		803
709	This request can be used to get the absolute path of the current working	804	This request can be used to get the absolute path of the current working
710	directory by passing it a path of F<.> (a single dot).	805	directory by passing it a path of F<.> (a single dot).
711		806
712		807
713	=item aio_rename $srcpath, $dstpath, $callback->($status)	808	=item aio_rename $srcpath, $dstpath, $callback->($status)
714		809
715	Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as	810	Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as
716	rename(2) and call the callback with the result code.	811	rename(2) and call the callback with the result code.
		812
		813	On systems that support the AIO::WD working directory abstraction
		814	natively, the case C<[$wd, "."]> as C<$srcpath> is specialcased - instead
		815	of failing, C<rename> is called on the absolute path of C<$wd>.
		816
		817
		818	=item aio_rename2 $srcpath, $dstpath, $flags, $callback->($status)
		819
		820	Basically a version of C<aio_rename> with an additional C<$flags>
		821	argument. Calling this with C<$flags=0> is the same as calling
		822	C<aio_rename>.
		823
		824	Non-zero flags are currently only supported on GNU/Linux systems that
		825	support renameat2. Other systems fail with C<ENOSYS> in this case.
		826
		827	The following constants are available (missing ones are, as usual C<0>),
		828	see renameat2(2) for details:
		829
		830	C<IO::AIO::RENAME_NOREPLACE>, C<IO::AIO::RENAME_EXCHANGE>
		831	and C<IO::AIO::RENAME_WHITEOUT>.
717		832
718		833
719	=item aio_mkdir $pathname, $mode, $callback->($status)	834	=item aio_mkdir $pathname, $mode, $callback->($status)
720		835
721	Asynchronously mkdir (create) a directory and call the callback with	836	Asynchronously mkdir (create) a directory and call the callback with
…		…
725		840
726	=item aio_rmdir $pathname, $callback->($status)	841	=item aio_rmdir $pathname, $callback->($status)
727		842
728	Asynchronously rmdir (delete) a directory and call the callback with the	843	Asynchronously rmdir (delete) a directory and call the callback with the
729	result code.	844	result code.
		845
		846	On systems that support the AIO::WD working directory abstraction
		847	natively, the case C<[$wd, "."]> is specialcased - instead of failing,
		848	C<rmdir> is called on the absolute path of C<$wd>.
730		849
731		850
732	=item aio_readdir $pathname, $callback->($entries)	851	=item aio_readdir $pathname, $callback->($entries)
733		852
734	Unlike the POSIX call of the same name, C<aio_readdir> reads an entire	853	Unlike the POSIX call of the same name, C<aio_readdir> reads an entire
…		…
1099	}	1218	}
1100		1219
1101	=item aio_rmtree $pathname, $callback->($status)	1220	=item aio_rmtree $pathname, $callback->($status)
1102		1221
1103	Delete a directory tree starting (and including) C<$path>, return the	1222	Delete a directory tree starting (and including) C<$path>, return the
1104	status of the final C<rmdir> only. This is a composite request that	1223	status of the final C<rmdir> only. This is a composite request that
1105	uses C<aio_scandir> to recurse into and rmdir directories, and unlink	1224	uses C<aio_scandir> to recurse into and rmdir directories, and unlink
1106	everything else.	1225	everything else.
1107		1226
1108	=cut	1227	=cut
1109		1228
…		…
1130	add $grp $dirgrp;	1249	add $grp $dirgrp;
1131	};	1250	};
1132		1251
1133	$grp	1252	$grp
1134	}	1253	}
		1254
		1255	=item aio_fcntl $fh, $cmd, $arg, $callback->($status)
		1256
		1257	=item aio_ioctl $fh, $request, $buf, $callback->($status)
		1258
		1259	These work just like the C<fcntl> and C<ioctl> built-in functions, except
		1260	they execute asynchronously and pass the return value to the callback.
		1261
		1262	Both calls can be used for a lot of things, some of which make more sense
		1263	to run asynchronously in their own thread, while some others make less
		1264	sense. For example, calls that block waiting for external events, such
		1265	as locking, will also lock down an I/O thread while it is waiting, which
		1266	can deadlock the whole I/O system. At the same time, there might be no
		1267	alternative to using a thread to wait.
		1268
		1269	So in general, you should only use these calls for things that do
		1270	(filesystem) I/O, not for things that wait for other events (network,
		1271	other processes), although if you are careful and know what you are doing,
		1272	you still can.
		1273
		1274	The following constants are available (missing ones are, as usual C<0>):
		1275
		1276	C<FIFREEZE>, C<FITHAW>, C<FITRIM>, C<FICLONE>, C<FICLONERANGE>, C<FIDEDUPERANGE>.
		1277
		1278	C<FS_IOC_GETFLAGS>, C<FS_IOC_SETFLAGS>, C<FS_IOC_GETVERSION>, C<FS_IOC_SETVERSION>,
		1279	C<FS_IOC_FIEMAP>.
		1280
		1281	C<FS_IOC_FSGETXATTR>, C<FS_IOC_FSSETXATTR>, C<FS_IOC_SET_ENCRYPTION_POLICY>,
		1282	C<FS_IOC_GET_ENCRYPTION_PWSALT>, C<FS_IOC_GET_ENCRYPTION_POLICY>, C<FS_KEY_DESCRIPTOR_SIZE>.
		1283
		1284	C<FS_SECRM_FL>, C<FS_UNRM_FL>, C<FS_COMPR_FL>, C<FS_SYNC_FL>, C<FS_IMMUTABLE_FL>,
		1285	C<FS_APPEND_FL>, C<FS_NODUMP_FL>, C<FS_NOATIME_FL>, C<FS_DIRTY_FL>,
		1286	C<FS_COMPRBLK_FL>, C<FS_NOCOMP_FL>, C<FS_ENCRYPT_FL>, C<FS_BTREE_FL>,
		1287	C<FS_INDEX_FL>, C<FS_JOURNAL_DATA_FL>, C<FS_NOTAIL_FL>, C<FS_DIRSYNC_FL>, C<FS_TOPDIR_FL>,
		1288	C<FS_FL_USER_MODIFIABLE>.
		1289
		1290	C<FS_XFLAG_REALTIME>, C<FS_XFLAG_PREALLOC>, C<FS_XFLAG_IMMUTABLE>, C<FS_XFLAG_APPEND>,
		1291	C<FS_XFLAG_SYNC>, C<FS_XFLAG_NOATIME>, C<FS_XFLAG_NODUMP>, C<FS_XFLAG_RTINHERIT>,
		1292	C<FS_XFLAG_PROJINHERIT>, C<FS_XFLAG_NOSYMLINKS>, C<FS_XFLAG_EXTSIZE>, C<FS_XFLAG_EXTSZINHERIT>,
		1293	C<FS_XFLAG_NODEFRAG>, C<FS_XFLAG_FILESTREAM>, C<FS_XFLAG_DAX>, C<FS_XFLAG_HASATTR>,
1135		1294
1136	=item aio_sync $callback->($status)	1295	=item aio_sync $callback->($status)
1137		1296
1138	Asynchronously call sync and call the callback when finished.	1297	Asynchronously call sync and call the callback when finished.
1139		1298
…		…
1208	};	1367	};
1209		1368
1210	$grp	1369	$grp
1211	}	1370	}
1212		1371
1213	=item aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)	1372	=item aio_msync $scalar, $offset = 0, $length = undef, flags = MS_SYNC, $callback->($status)
1214		1373
1215	This is a rather advanced IO::AIO call, which only works on mmap(2)ed	1374	This is a rather advanced IO::AIO call, which only works on mmap(2)ed
1216	scalars (see the C<IO::AIO::mmap> function, although it also works on data	1375	scalars (see the C<IO::AIO::mmap> function, although it also works on data
1217	scalars managed by the L<Sys::Mmap> or L<Mmap> modules, note that the	1376	scalars managed by the L<Sys::Mmap> or L<Mmap> modules, note that the
1218	scalar must only be modified in-place while an aio operation is pending on	1377	scalar must only be modified in-place while an aio operation is pending on
…		…
1220		1379
1221	It calls the C<msync> function of your OS, if available, with the memory	1380	It calls the C<msync> function of your OS, if available, with the memory
1222	area starting at C<$offset> in the string and ending C<$length> bytes	1381	area starting at C<$offset> in the string and ending C<$length> bytes
1223	later. If C<$length> is negative, counts from the end, and if C<$length>	1382	later. If C<$length> is negative, counts from the end, and if C<$length>
1224	is C<undef>, then it goes till the end of the string. The flags can be	1383	is C<undef>, then it goes till the end of the string. The flags can be
1225	a combination of C<IO::AIO::MS_ASYNC>, C<IO::AIO::MS_INVALIDATE> and	1384	either C<IO::AIO::MS_ASYNC> or C<IO::AIO::MS_SYNC>, plus an optional
1226	C<IO::AIO::MS_SYNC>.	1385	C<IO::AIO::MS_INVALIDATE>.
1227		1386
1228	=item aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)	1387	=item aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
1229		1388
1230	This is a rather advanced IO::AIO call, which works best on mmap(2)ed	1389	This is a rather advanced IO::AIO call, which works best on mmap(2)ed
1231	scalars.	1390	scalars.
1232		1391
1233	It touches (reads or writes) all memory pages in the specified	1392	It touches (reads or writes) all memory pages in the specified
1234	range inside the scalar. All caveats and parameters are the same	1393	range inside the scalar. All caveats and parameters are the same
1235	as for C<aio_msync>, above, except for flags, which must be either	1394	as for C<aio_msync>, above, except for flags, which must be either
1236	C<0> (which reads all pages and ensures they are instantiated) or	1395	C<0> (which reads all pages and ensures they are instantiated) or
1237	C<IO::AIO::MT_MODIFY>, which modifies the memory page s(by reading and	1396	C<IO::AIO::MT_MODIFY>, which modifies the memory pages (by reading and
1238	writing an octet from it, which dirties the page).	1397	writing an octet from it, which dirties the page).
1239		1398
1240	=item aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status)	1399	=item aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status)
1241		1400
1242	This is a rather advanced IO::AIO call, which works best on mmap(2)ed	1401	This is a rather advanced IO::AIO call, which works best on mmap(2)ed
…		…
1276		1435
1277	aio_mlockall IO::AIO::MCL_FUTURE;	1436	aio_mlockall IO::AIO::MCL_FUTURE;
1278		1437
1279	=item aio_fiemap $fh, $start, $length, $flags, $count, $cb->(\@extents)	1438	=item aio_fiemap $fh, $start, $length, $flags, $count, $cb->(\@extents)
1280		1439
1281	Queries the extents of the given file (by calling the Linux FIEMAP ioctl,	1440	Queries the extents of the given file (by calling the Linux C<FIEMAP>
1282	see L<http://cvs.schmorp.de/IO-AIO/doc/fiemap.txt> for details). If the	1441	ioctl, see L<http://cvs.schmorp.de/IO-AIO/doc/fiemap.txt> for details). If
1283	C<ioctl> is not available on your OS, then this rquiest will fail with	1442	the ioctl is not available on your OS, then this request will fail with
1284	C<ENOSYS>.	1443	C<ENOSYS>.
1285		1444
1286	C<$start> is the starting offset to query extents for, C<$length> is the	1445	C<$start> is the starting offset to query extents for, C<$length> is the
1287	size of the range to query - if it is C<undef>, then the whole file will	1446	size of the range to query - if it is C<undef>, then the whole file will
1288	be queried.	1447	be queried.
…		…
1291	C<IO::AIO::FIEMAP_FLAG_XATTR> - C<IO::AIO::FIEMAP_FLAGS_COMPAT> is also	1450	C<IO::AIO::FIEMAP_FLAG_XATTR> - C<IO::AIO::FIEMAP_FLAGS_COMPAT> is also
1292	exported), and is normally C<0> or C<IO::AIO::FIEMAP_FLAG_SYNC> to query	1451	exported), and is normally C<0> or C<IO::AIO::FIEMAP_FLAG_SYNC> to query
1293	the data portion.	1452	the data portion.
1294		1453
1295	C<$count> is the maximum number of extent records to return. If it is	1454	C<$count> is the maximum number of extent records to return. If it is
1296	C<undef>, then IO::AIO queries all extents of the file. As a very special	1455	C<undef>, then IO::AIO queries all extents of the range. As a very special
1297	case, if it is C<0>, then the callback receives the number of extents	1456	case, if it is C<0>, then the callback receives the number of extents
1298	instead of the extents themselves.	1457	instead of the extents themselves (which is unreliable, see below).
1299		1458
1300	If an error occurs, the callback receives no arguments. The special	1459	If an error occurs, the callback receives no arguments. The special
1301	C<errno> value C<IO::AIO::EBADR> is available to test for flag errors.	1460	C<errno> value C<IO::AIO::EBADR> is available to test for flag errors.
1302		1461
1303	Otherwise, the callback receives an array reference with extent	1462	Otherwise, the callback receives an array reference with extent
…		…
1305	following members:	1464	following members:
1306		1465
1307	[$logical, $physical, $length, $flags]	1466	[$logical, $physical, $length, $flags]
1308		1467
1309	Flags is any combination of the following flag values (typically either C<0>	1468	Flags is any combination of the following flag values (typically either C<0>
1310	or C<IO::AIO::FIEMAP_EXTENT_LAST>):	1469	or C<IO::AIO::FIEMAP_EXTENT_LAST> (1)):
1311		1470
1312	C<IO::AIO::FIEMAP_EXTENT_LAST>, C<IO::AIO::FIEMAP_EXTENT_UNKNOWN>,	1471	C<IO::AIO::FIEMAP_EXTENT_LAST>, C<IO::AIO::FIEMAP_EXTENT_UNKNOWN>,
1313	C<IO::AIO::FIEMAP_EXTENT_DELALLOC>, C<IO::AIO::FIEMAP_EXTENT_ENCODED>,	1472	C<IO::AIO::FIEMAP_EXTENT_DELALLOC>, C<IO::AIO::FIEMAP_EXTENT_ENCODED>,
1314	C<IO::AIO::FIEMAP_EXTENT_DATA_ENCRYPTED>, C<IO::AIO::FIEMAP_EXTENT_NOT_ALIGNED>,	1473	C<IO::AIO::FIEMAP_EXTENT_DATA_ENCRYPTED>, C<IO::AIO::FIEMAP_EXTENT_NOT_ALIGNED>,
1315	C<IO::AIO::FIEMAP_EXTENT_DATA_INLINE>, C<IO::AIO::FIEMAP_EXTENT_DATA_TAIL>,	1474	C<IO::AIO::FIEMAP_EXTENT_DATA_INLINE>, C<IO::AIO::FIEMAP_EXTENT_DATA_TAIL>,
1316	C<IO::AIO::FIEMAP_EXTENT_UNWRITTEN>, C<IO::AIO::FIEMAP_EXTENT_MERGED> or	1475	C<IO::AIO::FIEMAP_EXTENT_UNWRITTEN>, C<IO::AIO::FIEMAP_EXTENT_MERGED> or
1317	C<IO::AIO::FIEMAP_EXTENT_SHARED>.	1476	C<IO::AIO::FIEMAP_EXTENT_SHARED>.
1318		1477
		1478	At the time of this writing (Linux 3.2), this requets is unreliable unless
		1479	C<$count> is C<undef>, as the kernel has all sorts of bugs preventing
		1480	it to return all extents of a range for files with large number of
		1481	extents. The code works around all these issues if C<$count> is undef.
		1482
1319	=item aio_group $callback->(...)	1483	=item aio_group $callback->(...)
1320		1484
1321	This is a very special aio request: Instead of doing something, it is a	1485	This is a very special aio request: Instead of doing something, it is a
1322	container for other aio requests, which is useful if you want to bundle	1486	container for other aio requests, which is useful if you want to bundle
1323	many requests into a single, composite, request with a definite callback	1487	many requests into a single, composite, request with a definite callback
…		…
1406	aio_stat [$etcdir, "passwd"], sub {	1570	aio_stat [$etcdir, "passwd"], sub {
1407	# yay	1571	# yay
1408	};	1572	};
1409	};	1573	};
1410		1574
1411	That C<aio_wd> is a request and not a normal function shows that creating	1575	The fact that C<aio_wd> is a request and not a normal function shows that
1412	an IO::AIO::WD object is itself a potentially blocking operation, which is	1576	creating an IO::AIO::WD object is itself a potentially blocking operation,
1413	why it is done asynchronously.	1577	which is why it is done asynchronously.
1414		1578
1415	To stat the directory obtained with C<aio_wd> above, one could write	1579	To stat the directory obtained with C<aio_wd> above, one could write
1416	either of the following three request calls:	1580	either of the following three request calls:
1417		1581
1418	aio_lstat "/etc" , sub { ... # pathname as normal string	1582	aio_lstat "/etc" , sub { ... # pathname as normal string
…		…
1438	will still point to the original directory. Most functions accepting a	1602	will still point to the original directory. Most functions accepting a
1439	pathname will use the directory fd on newer systems, and the string on	1603	pathname will use the directory fd on newer systems, and the string on
1440	older systems. Some functions (such as realpath) will always rely on the	1604	older systems. Some functions (such as realpath) will always rely on the
1441	string form of the pathname.	1605	string form of the pathname.
1442		1606
1443	So this fucntionality is mainly useful to get some protection against	1607	So this functionality is mainly useful to get some protection against
1444	C<chdir>, to easily get an absolute path out of a relative path for future	1608	C<chdir>, to easily get an absolute path out of a relative path for future
1445	reference, and to speed up doing many operations in the same directory	1609	reference, and to speed up doing many operations in the same directory
1446	(e.g. when stat'ing all files in a directory).	1610	(e.g. when stat'ing all files in a directory).
1447		1611
1448	The following functions implement this working directory abstraction:	1612	The following functions implement this working directory abstraction:
…		…
1461	passing C<undef> as working directory component of a pathname fails the	1625	passing C<undef> as working directory component of a pathname fails the
1462	request with C<ENOENT>, there is often no need for error checking in the	1626	request with C<ENOENT>, there is often no need for error checking in the
1463	C<aio_wd> callback, as future requests using the value will fail in the	1627	C<aio_wd> callback, as future requests using the value will fail in the
1464	expected way.	1628	expected way.
1465		1629
1466	If this call isn't available because your OS lacks it or it couldn't be
1467	detected, it will be emulated by calling C<fsync> instead.
1468
1469	=item IO::AIO::CWD	1630	=item IO::AIO::CWD
1470		1631
1471	This is a compiletime constant (object) that represents the process	1632	This is a compiletime constant (object) that represents the process
1472	current working directory.	1633	current working directory.
1473		1634
1474	Specifying this object as working directory object for a pathname is as	1635	Specifying this object as working directory object for a pathname is as if
1475	if the pathname would be specified directly, without a directory object,	1636	the pathname would be specified directly, without a directory object. For
1476	e.g., these calls are functionally identical:	1637	example, these calls are functionally identical:
1477		1638
1478	aio_stat "somefile", sub { ... };	1639	aio_stat "somefile", sub { ... };
1479	aio_stat [IO::AIO::CWD, "somefile"], sub { ... };	1640	aio_stat [IO::AIO::CWD, "somefile"], sub { ... };
1480		1641
1481	=back	1642	=back
1482		1643
		1644	To recover the path associated with an IO::AIO::WD object, you can use
		1645	C<aio_realpath>:
		1646
		1647	aio_realpath $wd, sub {
		1648	warn "path is $_[0]\n";
		1649	};
		1650
		1651	Currently, C<aio_statvfs> always, and C<aio_rename> and C<aio_rmdir>
		1652	sometimes, fall back to using an absolue path.
1483		1653
1484	=head2 IO::AIO::REQ CLASS	1654	=head2 IO::AIO::REQ CLASS
1485		1655
1486	All non-aggregate C<aio_*> functions return an object of this class when	1656	All non-aggregate C<aio_*> functions return an object of this class when
1487	called in non-void context.	1657	called in non-void context.
…		…
1665		1835
1666	See C<poll_cb> for an example.	1836	See C<poll_cb> for an example.
1667		1837
1668	=item IO::AIO::poll_cb	1838	=item IO::AIO::poll_cb
1669		1839
1670	Process some outstanding events on the result pipe. You have to call	1840	Process some requests that have reached the result phase (i.e. they have
		1841	been executed but the results are not yet reported). You have to call
		1842	this "regularly" to finish outstanding requests.
		1843
1671	this regularly. Returns C<0> if all events could be processed (or there	1844	Returns C<0> if all events could be processed (or there were no
1672	were no events to process), or C<-1> if it returned earlier for whatever	1845	events to process), or C<-1> if it returned earlier for whatever
1673	reason. Returns immediately when no events are outstanding. The amount of	1846	reason. Returns immediately when no events are outstanding. The amount
1674	events processed depends on the settings of C<IO::AIO::max_poll_req> and	1847	of events processed depends on the settings of C<IO::AIO::max_poll_req>,
1675	C<IO::AIO::max_poll_time>.	1848	C<IO::AIO::max_poll_time> and C<IO::AIO::max_outstanding>.
1676		1849
1677	If not all requests were processed for whatever reason, the filehandle	1850	If not all requests were processed for whatever reason, the poll file
1678	will still be ready when C<poll_cb> returns, so normally you don't have to	1851	descriptor will still be ready when C<poll_cb> returns, so normally you
1679	do anything special to have it called later.	1852	don't have to do anything special to have it called later.
1680		1853
1681	Apart from calling C<IO::AIO::poll_cb> when the event filehandle becomes	1854	Apart from calling C<IO::AIO::poll_cb> when the event filehandle becomes
1682	ready, it can be beneficial to call this function from loops which submit	1855	ready, it can be beneficial to call this function from loops which submit
1683	a lot of requests, to make sure the results get processed when they become	1856	a lot of requests, to make sure the results get processed when they become
1684	available and not just when the loop is finished and the event loop takes	1857	available and not just when the loop is finished and the event loop takes
…		…
1693	poll => 'r', async => 1,	1866	poll => 'r', async => 1,
1694	cb => \&IO::AIO::poll_cb);	1867	cb => \&IO::AIO::poll_cb);
1695		1868
1696	=item IO::AIO::poll_wait	1869	=item IO::AIO::poll_wait
1697		1870
1698	If there are any outstanding requests and none of them in the result	1871	Wait until either at least one request is in the result phase or no
1699	phase, wait till the result filehandle becomes ready for reading (simply	1872	requests are outstanding anymore.
1700	does a C<select> on the filehandle. This is useful if you want to	1873
1701	synchronously wait for some requests to finish).	1874	This is useful if you want to synchronously wait for some requests to
		1875	become ready, without actually handling them.
1702		1876
1703	See C<nreqs> for an example.	1877	See C<nreqs> for an example.
1704		1878
1705	=item IO::AIO::poll	1879	=item IO::AIO::poll
1706		1880
…		…
1827		2001
1828	This is a very bad function to use in interactive programs because it	2002	This is a very bad function to use in interactive programs because it
1829	blocks, and a bad way to reduce concurrency because it is inexact: Better	2003	blocks, and a bad way to reduce concurrency because it is inexact: Better
1830	use an C<aio_group> together with a feed callback.	2004	use an C<aio_group> together with a feed callback.
1831		2005
1832	It's main use is in scripts without an event loop - when you want to stat	2006	Its main use is in scripts without an event loop - when you want to stat
1833	a lot of files, you can write somehting like this:	2007	a lot of files, you can write somehting like this:
1834		2008
1835	IO::AIO::max_outstanding 32;	2009	IO::AIO::max_outstanding 32;
1836		2010
1837	for my $path (...) {	2011	for my $path (...) {
…		…
1877		2051
1878	=back	2052	=back
1879		2053
1880	=head3 MISCELLANEOUS FUNCTIONS	2054	=head3 MISCELLANEOUS FUNCTIONS
1881		2055
1882	IO::AIO implements some functions that might be useful, but are not	2056	IO::AIO implements some functions that are useful when you want to use
1883	asynchronous.	2057	some "Advanced I/O" function not available to in Perl, without going the
		2058	"Asynchronous I/O" route. Many of these have an asynchronous C<aio_*>
		2059	counterpart.
1884		2060
1885	=over 4	2061	=over 4
1886		2062
1887	=item IO::AIO::sendfile $ofh, $ifh, $offset, $count	2063	=item IO::AIO::sendfile $ofh, $ifh, $offset, $count
1888		2064
…		…
1907	=item IO::AIO::madvise $scalar, $offset, $len, $advice	2083	=item IO::AIO::madvise $scalar, $offset, $len, $advice
1908		2084
1909	Simply calls the C<posix_madvise> function (see its	2085	Simply calls the C<posix_madvise> function (see its
1910	manpage for details). The following advice constants are	2086	manpage for details). The following advice constants are
1911	available: C<IO::AIO::MADV_NORMAL>, C<IO::AIO::MADV_SEQUENTIAL>,	2087	available: C<IO::AIO::MADV_NORMAL>, C<IO::AIO::MADV_SEQUENTIAL>,
1912	C<IO::AIO::MADV_RANDOM>, C<IO::AIO::MADV_WILLNEED>, C<IO::AIO::MADV_DONTNEED>.	2088	C<IO::AIO::MADV_RANDOM>, C<IO::AIO::MADV_WILLNEED>, C<IO::AIO::MADV_DONTNEED>,
		2089	C<IO::AIO::MADV_FREE>.
		2090
		2091	If C<$offset> is negative, counts from the end. If C<$length> is negative,
		2092	the remaining length of the C<$scalar> is used. If possible, C<$length>
		2093	will be reduced to fit into the C<$scalar>.
1913		2094
1914	On systems that do not implement C<posix_madvise>, this function returns	2095	On systems that do not implement C<posix_madvise>, this function returns
1915	ENOSYS, otherwise the return value of C<posix_madvise>.	2096	ENOSYS, otherwise the return value of C<posix_madvise>.
1916		2097
1917	=item IO::AIO::mprotect $scalar, $offset, $len, $protect	2098	=item IO::AIO::mprotect $scalar, $offset, $len, $protect
…		…
1919	Simply calls the C<mprotect> function on the preferably AIO::mmap'ed	2100	Simply calls the C<mprotect> function on the preferably AIO::mmap'ed
1920	$scalar (see its manpage for details). The following protect	2101	$scalar (see its manpage for details). The following protect
1921	constants are available: C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_READ>,	2102	constants are available: C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_READ>,
1922	C<IO::AIO::PROT_WRITE>, C<IO::AIO::PROT_EXEC>.	2103	C<IO::AIO::PROT_WRITE>, C<IO::AIO::PROT_EXEC>.
1923		2104
		2105	If C<$offset> is negative, counts from the end. If C<$length> is negative,
		2106	the remaining length of the C<$scalar> is used. If possible, C<$length>
		2107	will be reduced to fit into the C<$scalar>.
		2108
1924	On systems that do not implement C<mprotect>, this function returns	2109	On systems that do not implement C<mprotect>, this function returns
1925	ENOSYS, otherwise the return value of C<mprotect>.	2110	ENOSYS, otherwise the return value of C<mprotect>.
1926		2111
1927	=item IO::AIO::mmap $scalar, $length, $prot, $flags, $fh[, $offset]	2112	=item IO::AIO::mmap $scalar, $length, $prot, $flags, $fh[, $offset]
1928		2113
1929	Memory-maps a file (or anonymous memory range) and attaches it to the	2114	Memory-maps a file (or anonymous memory range) and attaches it to the
1930	given C<$scalar>, which will act like a string scalar. Returns true on	2115	given C<$scalar>, which will act like a string scalar. Returns true on
1931	success, and false otherwise.	2116	success, and false otherwise.
1932		2117
		2118	The scalar must exist, but its contents do not matter - this means you
		2119	cannot use a nonexistant array or hash element. When in doubt, C<undef>
		2120	the scalar first.
		2121
1933	The only operations allowed on the scalar are C<substr>/C<vec> that don't	2122	The only operations allowed on the mmapped scalar are C<substr>/C<vec>,
1934	change the string length, and most read-only operations such as copying it	2123	which don't change the string length, and most read-only operations such
1935	or searching it with regexes and so on.	2124	as copying it or searching it with regexes and so on.
1936		2125
1937	Anything else is unsafe and will, at best, result in memory leaks.	2126	Anything else is unsafe and will, at best, result in memory leaks.
1938		2127
1939	The memory map associated with the C<$scalar> is automatically removed	2128	The memory map associated with the C<$scalar> is automatically removed
1940	when the C<$scalar> is destroyed, or when the C<IO::AIO::mmap> or	2129	when the C<$scalar> is undef'd or destroyed, or when the C<IO::AIO::mmap>
1941	C<IO::AIO::munmap> functions are called.	2130	or C<IO::AIO::munmap> functions are called on it.
1942		2131
1943	This calls the C<mmap>(2) function internally. See your system's manual	2132	This calls the C<mmap>(2) function internally. See your system's manual
1944	page for details on the C<$length>, C<$prot> and C<$flags> parameters.	2133	page for details on the C<$length>, C<$prot> and C<$flags> parameters.
1945		2134
1946	The C<$length> must be larger than zero and smaller than the actual	2135	The C<$length> must be larger than zero and smaller than the actual
1947	filesize.	2136	filesize.
1948		2137
1949	C<$prot> is a combination of C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_EXEC>,	2138	C<$prot> is a combination of C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_EXEC>,
1950	C<IO::AIO::PROT_READ> and/or C<IO::AIO::PROT_WRITE>,	2139	C<IO::AIO::PROT_READ> and/or C<IO::AIO::PROT_WRITE>,
1951		2140
1952	C<$flags> can be a combination of C<IO::AIO::MAP_SHARED> or	2141	C<$flags> can be a combination of
1953	C<IO::AIO::MAP_PRIVATE>, or a number of system-specific flags (when	2142	C<IO::AIO::MAP_SHARED> or
1954	not available, the are defined as 0): C<IO::AIO::MAP_ANONYMOUS>	2143	C<IO::AIO::MAP_PRIVATE>,
		2144	or a number of system-specific flags (when not available, the are C<0>):
1955	(which is set to C<MAP_ANON> if your system only provides this	2145	C<IO::AIO::MAP_ANONYMOUS> (which is set to C<MAP_ANON> if your system only provides this constant),
1956	constant), C<IO::AIO::MAP_HUGETLB>, C<IO::AIO::MAP_LOCKED>,	2146	C<IO::AIO::MAP_LOCKED>,
1957	C<IO::AIO::MAP_NORESERVE>, C<IO::AIO::MAP_POPULATE> or	2147	C<IO::AIO::MAP_NORESERVE>,
		2148	C<IO::AIO::MAP_POPULATE>,
1958	C<IO::AIO::MAP_NONBLOCK>	2149	C<IO::AIO::MAP_NONBLOCK>,
		2150	C<IO::AIO::MAP_FIXED>,
		2151	C<IO::AIO::MAP_GROWSDOWN>,
		2152	C<IO::AIO::MAP_32BIT>,
		2153	C<IO::AIO::MAP_HUGETLB> or
		2154	C<IO::AIO::MAP_STACK>.
1959		2155
1960	If C<$fh> is C<undef>, then a file descriptor of C<-1> is passed.	2156	If C<$fh> is C<undef>, then a file descriptor of C<-1> is passed.
1961		2157
1962	C<$offset> is the offset from the start of the file - it generally must be	2158	C<$offset> is the offset from the start of the file - it generally must be
1963	a multiple of C<IO::AIO::PAGESIZE> and defaults to C<0>.	2159	a multiple of C<IO::AIO::PAGESIZE> and defaults to C<0>.
…		…
2006		2202
2007	See the C<splice(2)> manpage for details.	2203	See the C<splice(2)> manpage for details.
2008		2204
2009	=item IO::AIO::tee $r_fh, $w_fh, $length, $flags	2205	=item IO::AIO::tee $r_fh, $w_fh, $length, $flags
2010		2206
2011	Calls the GNU/Linux C<tee(2)> syscall, see it's manpage and the	2207	Calls the GNU/Linux C<tee(2)> syscall, see its manpage and the
2012	description for C<IO::AIO::splice> above for details.	2208	description for C<IO::AIO::splice> above for details.
		2209
		2210	=item $actual_size = IO::AIO::pipesize $r_fh[, $new_size]
		2211
		2212	Attempts to query or change the pipe buffer size. Obviously works only
		2213	on pipes, and currently works only on GNU/Linux systems, and fails with
		2214	C<-1>/C<ENOSYS> everywhere else. If anybody knows how to influence pipe buffer
		2215	size on other systems, drop me a note.
		2216
		2217	=item ($rfh, $wfh) = IO::AIO::pipe2 [$flags]
		2218
		2219	This is a direct interface to the Linux L<pipe2(2)> system call. If
		2220	C<$flags> is missing or C<0>, then this should be the same as a call to
		2221	perl's built-in C<pipe> function and create a new pipe, and works on
		2222	systems that lack the pipe2 syscall. On win32, this case invokes C<_pipe
		2223	(..., 4096, O_BINARY)>.
		2224
		2225	If C<$flags> is non-zero, it tries to invoke the pipe2 system call with
		2226	the given flags (Linux 2.6.27, glibc 2.9).
		2227
		2228	On success, the read and write file handles are returned.
		2229
		2230	On error, nothing will be returned. If the pipe2 syscall is missing and
		2231	C<$flags> is non-zero, fails with C<ENOSYS>.
		2232
		2233	Please refer to L<pipe2(2)> for more info on the C<$flags>, but at the
		2234	time of this writing, C<IO::AIO::O_CLOEXEC>, C<IO::AIO::O_NONBLOCK> and
		2235	C<IO::AIO::O_DIRECT> (Linux 3.4, for packet-based pipes) were supported.
2013		2236
2014	=back	2237	=back
2015		2238
2016	=cut	2239	=cut
2017		2240

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Comparing IO-AIO/AIO.pm (file contents): Revision 1.229 by root, Wed Jul 25 16:32:30 2012 UTC vs. Revision 1.270 by root, Fri Jun 23 03:23:19 2017 UTC

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Comparing IO-AIO/AIO.pm (file contents):
Revision 1.229 by root, Wed Jul 25 16:32:30 2012 UTC vs.
Revision 1.270 by root, Fri Jun 23 03:23:19 2017 UTC