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

Comparing IO-AIO/AIO.pm (file contents):
Revision 1.225 by root, Tue Apr 10 05:01:33 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)
…		…
221	aio_statvfs $fh_or_path, $callback->($statvfs)	224	aio_statvfs $fh_or_path, $callback->($statvfs)
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)
		229	aio_allocate $fh, $mode, $offset, $len, $callback->($status)
		230	aio_fiemap $fh, $start, $length, $flags, $count, $cb->(\@extents)
226	aio_unlink $pathname, $callback->($status)	231	aio_unlink $pathname, $callback->($status)
227	aio_mknod $pathname, $mode, $dev, $callback->($status)	232	aio_mknod $pathname, $mode, $dev, $callback->($status)
228	aio_link $srcpath, $dstpath, $callback->($status)	233	aio_link $srcpath, $dstpath, $callback->($status)
229	aio_symlink $srcpath, $dstpath, $callback->($status)	234	aio_symlink $srcpath, $dstpath, $callback->($status)
230	aio_readlink $pathname, $callback->($link)	235	aio_readlink $pathname, $callback->($link)
231	aio_realpath $pathname, $callback->($link)	236	aio_realpath $pathname, $callback->($path)
232	aio_rename $srcpath, $dstpath, $callback->($status)	237	aio_rename $srcpath, $dstpath, $callback->($status)
		238	aio_rename2 $srcpath, $dstpath, $flags, $callback->($status)
233	aio_mkdir $pathname, $mode, $callback->($status)	239	aio_mkdir $pathname, $mode, $callback->($status)
234	aio_rmdir $pathname, $callback->($status)	240	aio_rmdir $pathname, $callback->($status)
235	aio_readdir $pathname, $callback->($entries)	241	aio_readdir $pathname, $callback->($entries)
236	aio_readdirx $pathname, $flags, $callback->($entries, $flags)	242	aio_readdirx $pathname, $flags, $callback->($entries, $flags)
237	IO::AIO::READDIR_DENTS IO::AIO::READDIR_DIRS_FIRST	243	IO::AIO::READDIR_DENTS IO::AIO::READDIR_DIRS_FIRST
…		…
239	aio_scandir $pathname, $maxreq, $callback->($dirs, $nondirs)	245	aio_scandir $pathname, $maxreq, $callback->($dirs, $nondirs)
240	aio_load $pathname, $data, $callback->($status)	246	aio_load $pathname, $data, $callback->($status)
241	aio_copy $srcpath, $dstpath, $callback->($status)	247	aio_copy $srcpath, $dstpath, $callback->($status)
242	aio_move $srcpath, $dstpath, $callback->($status)	248	aio_move $srcpath, $dstpath, $callback->($status)
243	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)
244	aio_sync $callback->($status)	252	aio_sync $callback->($status)
245	aio_syncfs $fh, $callback->($status)	253	aio_syncfs $fh, $callback->($status)
246	aio_fsync $fh, $callback->($status)	254	aio_fsync $fh, $callback->($status)
247	aio_fdatasync $fh, $callback->($status)	255	aio_fdatasync $fh, $callback->($status)
248	aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status)	256	aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status)
249	aio_pathsync $pathname, $callback->($status)	257	aio_pathsync $pathname, $callback->($status)
250	aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)	258	aio_msync $scalar, $offset = 0, $length = undef, flags = MS_SYNC, $callback->($status)
251	aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)	259	aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
252	aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status)	260	aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status)
253	aio_mlockall $flags, $callback->($status)	261	aio_mlockall $flags, $callback->($status)
254	aio_group $callback->(...)	262	aio_group $callback->(...)
255	aio_nop $callback->()	263	aio_nop $callback->()
…		…
272	IO::AIO::nready	280	IO::AIO::nready
273	IO::AIO::npending	281	IO::AIO::npending
274		282
275	IO::AIO::sendfile $ofh, $ifh, $offset, $count	283	IO::AIO::sendfile $ofh, $ifh, $offset, $count
276	IO::AIO::fadvise $fh, $offset, $len, $advice	284	IO::AIO::fadvise $fh, $offset, $len, $advice
		285	IO::AIO::mmap $scalar, $length, $prot, $flags[, $fh[, $offset]]
		286	IO::AIO::munmap $scalar
277	IO::AIO::madvise $scalar, $offset, $length, $advice	287	IO::AIO::madvise $scalar, $offset, $length, $advice
278	IO::AIO::mprotect $scalar, $offset, $length, $protect	288	IO::AIO::mprotect $scalar, $offset, $length, $protect
279	IO::AIO::munlock $scalar, $offset = 0, $length = undef	289	IO::AIO::munlock $scalar, $offset = 0, $length = undef
280	IO::AIO::munlockall	290	IO::AIO::munlockall
281		291
…		…
358		368
359		369
360	=item aio_open $pathname, $flags, $mode, $callback->($fh)	370	=item aio_open $pathname, $flags, $mode, $callback->($fh)
361		371
362	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
363	created filehandle for the file.	373	created filehandle for the file (or C<undef> in case of an error).
364		374
365	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,
366	for an explanation.	376	for an explanation.
367		377
368	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
…		…
391	following POSIX and non-POSIX constants are available (missing ones on	401	following POSIX and non-POSIX constants are available (missing ones on
392	your system are, as usual, C<0>):	402	your system are, as usual, C<0>):
393		403
394	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>,
395	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>,
396	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>.
397		407
398		408
399	=item aio_close $fh, $callback->($status)	409	=item aio_close $fh, $callback->($status)
400		410
401	Asynchronously close a file and call the callback with the result	411	Asynchronously close a file and call the callback with the result
…		…
436	=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)	446	=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
437		447
438	=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)	448	=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
439		449
440	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
441	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
442	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
443	error, just like the syscall).	453	error, just like the syscall).
444		454
445	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
446	offset plus the actual number of bytes read.	456	offset plus the actual number of bytes read.
447		457
…		…
505	As native sendfile syscalls (as practically any non-POSIX interface hacked	515	As native sendfile syscalls (as practically any non-POSIX interface hacked
506	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
507	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
508	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,
509	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> -
510	fewre bytes than expected might have been transferred.	520	fewer bytes than expected might have been transferred.
511		521
512		522
513	=item aio_readahead $fh,$offset,$length, $callback->($retval)	523	=item aio_readahead $fh,$offset,$length, $callback->($retval)
514		524
515	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
…		…
519	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
520	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
521	(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
522	file. The current file offset of the file is left unchanged.	532	file. The current file offset of the file is left unchanged.
523		533
524	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
525	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.
526		536
527		537
528	=item aio_stat $fh_or_path, $callback->($status)	538	=item aio_stat $fh_or_path, $callback->($status)
529		539
530	=item aio_lstat $fh, $callback->($status)	540	=item aio_lstat $fh, $callback->($status)
…		…
599	namemax => 255,	609	namemax => 255,
600	frsize => 1024,	610	frsize => 1024,
601	fsid => 1810	611	fsid => 1810
602	}	612	}
603		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
604		698
605	=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status)	699	=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
606		700
607	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
608	and $mtime being undef). Fractional times are supported if the underlying	702	and $mtime being undef). Fractional times are supported if the underlying
…		…
636	=item aio_truncate $fh_or_path, $offset, $callback->($status)	730	=item aio_truncate $fh_or_path, $offset, $callback->($status)
637		731
638	Works like truncate(2) or ftruncate(2).	732	Works like truncate(2) or ftruncate(2).
639		733
640		734
		735	=item aio_allocate $fh, $mode, $offset, $len, $callback->($status)
		736
		737	Allocates or frees disk space according to the C<$mode> argument. See the
		738	linux C<fallocate> documentation for details.
		739
		740	C<$mode> is usually C<0> or C<IO::AIO::FALLOC_FL_KEEP_SIZE> to allocate
		741	space, or C<IO::AIO::FALLOC_FL_PUNCH_HOLE \| IO::AIO::FALLOC_FL_KEEP_SIZE>,
		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).
		747
		748	The file system block size used by C<fallocate> is presumably the
		749	C<f_bsize> returned by C<statvfs>.
		750
		751	If C<fallocate> isn't available or cannot be emulated (currently no
		752	emulation will be attempted), passes C<-1> and sets C<$!> to C<ENOSYS>.
		753
		754
641	=item aio_chmod $fh_or_path, $mode, $callback->($status)	755	=item aio_chmod $fh_or_path, $mode, $callback->($status)
642		756
643	Works like perl's C<chmod> function.	757	Works like perl's C<chmod> function.
644		758
645		759
…		…
682		796
683		797
684	=item aio_realpath $pathname, $callback->($path)	798	=item aio_realpath $pathname, $callback->($path)
685		799
686	Asynchronously make the path absolute and resolve any symlinks in	800	Asynchronously make the path absolute and resolve any symlinks in
687	C<$path>. The resulting path only consists of directories (Same as	801	C<$path>. The resulting path only consists of directories (same as
688	L<Cwd::realpath>).	802	L<Cwd::realpath>).
689		803
690	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
691	directory by passing it a path of F<.> (a single dot).	805	directory by passing it a path of F<.> (a single dot).
692		806
693		807
694	=item aio_rename $srcpath, $dstpath, $callback->($status)	808	=item aio_rename $srcpath, $dstpath, $callback->($status)
695		809
696	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
697	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>.
698		832
699		833
700	=item aio_mkdir $pathname, $mode, $callback->($status)	834	=item aio_mkdir $pathname, $mode, $callback->($status)
701		835
702	Asynchronously mkdir (create) a directory and call the callback with	836	Asynchronously mkdir (create) a directory and call the callback with
…		…
706		840
707	=item aio_rmdir $pathname, $callback->($status)	841	=item aio_rmdir $pathname, $callback->($status)
708		842
709	Asynchronously rmdir (delete) a directory and call the callback with the	843	Asynchronously rmdir (delete) a directory and call the callback with the
710	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>.
711		849
712		850
713	=item aio_readdir $pathname, $callback->($entries)	851	=item aio_readdir $pathname, $callback->($entries)
714		852
715	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
…		…
1080	}	1218	}
1081		1219
1082	=item aio_rmtree $pathname, $callback->($status)	1220	=item aio_rmtree $pathname, $callback->($status)
1083		1221
1084	Delete a directory tree starting (and including) C<$path>, return the	1222	Delete a directory tree starting (and including) C<$path>, return the
1085	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
1086	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
1087	everything else.	1225	everything else.
1088		1226
1089	=cut	1227	=cut
1090		1228
…		…
1111	add $grp $dirgrp;	1249	add $grp $dirgrp;
1112	};	1250	};
1113		1251
1114	$grp	1252	$grp
1115	}	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>,
1116		1294
1117	=item aio_sync $callback->($status)	1295	=item aio_sync $callback->($status)
1118		1296
1119	Asynchronously call sync and call the callback when finished.	1297	Asynchronously call sync and call the callback when finished.
1120		1298
…		…
1189	};	1367	};
1190		1368
1191	$grp	1369	$grp
1192	}	1370	}
1193		1371
1194	=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)
1195		1373
1196	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
1197	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
1198	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
1199	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
…		…
1201		1379
1202	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
1203	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
1204	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>
1205	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
1206	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
1207	C<IO::AIO::MS_SYNC>.	1385	C<IO::AIO::MS_INVALIDATE>.
1208		1386
1209	=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)
1210		1388
1211	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
1212	scalars.	1390	scalars.
1213		1391
1214	It touches (reads or writes) all memory pages in the specified	1392	It touches (reads or writes) all memory pages in the specified
1215	range inside the scalar. All caveats and parameters are the same	1393	range inside the scalar. All caveats and parameters are the same
1216	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
1217	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
1218	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
1219	writing an octet from it, which dirties the page).	1397	writing an octet from it, which dirties the page).
1220		1398
1221	=item aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status)	1399	=item aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status)
1222		1400
1223	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
…		…
1257		1435
1258	aio_mlockall IO::AIO::MCL_FUTURE;	1436	aio_mlockall IO::AIO::MCL_FUTURE;
1259		1437
1260	=item aio_fiemap $fh, $start, $length, $flags, $count, $cb->(\@extents)	1438	=item aio_fiemap $fh, $start, $length, $flags, $count, $cb->(\@extents)
1261		1439
1262	Queries the extents of the given file (by calling the Linux FIEMAP ioctl,	1440	Queries the extents of the given file (by calling the Linux C<FIEMAP>
1263	see L<http://cvs.schmorp.de/IO-AIO/doc/fiemap.txt> for details). If the	1441	ioctl, see L<http://cvs.schmorp.de/IO-AIO/doc/fiemap.txt> for details). If
1264	C<ioctl> is not available on your OS, then this rquiest will fail with	1442	the ioctl is not available on your OS, then this request will fail with
1265	C<ENOSYS>.	1443	C<ENOSYS>.
1266		1444
1267	C<$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<$length> is the
1268	size of the range to query - if it is C<undef>, then the whole file will	1446	size of the range to query - if it is C<undef>, then the whole file will
1269	be queried.	1447	be queried.
…		…
1272	C<IO::AIO::FIEMAP_FLAG_XATTR> - C<IO::AIO::FIEMAP_FLAGS_COMPAT> is also	1450	C<IO::AIO::FIEMAP_FLAG_XATTR> - C<IO::AIO::FIEMAP_FLAGS_COMPAT> is also
1273	exported), and is normally C<0> or C<IO::AIO::FIEMAP_FLAG_SYNC> to query	1451	exported), and is normally C<0> or C<IO::AIO::FIEMAP_FLAG_SYNC> to query
1274	the data portion.	1452	the data portion.
1275		1453
1276	C<$count> is the maximum number of extent records to return. If it is	1454	C<$count> is the maximum number of extent records to return. If it is
1277	C<undef>, then IO::AIO queries all extents of the file. As a very special	1455	C<undef>, then IO::AIO queries all extents of the range. As a very special
1278	case, if it is C<0>, then the callback receives the number of extents	1456	case, if it is C<0>, then the callback receives the number of extents
1279	instead of the extents themselves.	1457	instead of the extents themselves (which is unreliable, see below).
1280		1458
1281	If an error occurs, the callback receives no arguments. The special	1459	If an error occurs, the callback receives no arguments. The special
1282	C<errno> value C<IO::AIO::EBADR> is available to test for flag errors.	1460	C<errno> value C<IO::AIO::EBADR> is available to test for flag errors.
1283		1461
1284	Otherwise, the callback receives an array reference with extent	1462	Otherwise, the callback receives an array reference with extent
…		…
1286	following members:	1464	following members:
1287		1465
1288	[$logical, $physical, $length, $flags]	1466	[$logical, $physical, $length, $flags]
1289		1467
1290	Flags is any combination of the following flag values (typically either C<0>	1468	Flags is any combination of the following flag values (typically either C<0>
1291	or C<IO::AIO::FIEMAP_EXTENT_LAST>):	1469	or C<IO::AIO::FIEMAP_EXTENT_LAST> (1)):
1292		1470
1293	C<IO::AIO::FIEMAP_EXTENT_LAST>, C<IO::AIO::FIEMAP_EXTENT_UNKNOWN>,	1471	C<IO::AIO::FIEMAP_EXTENT_LAST>, C<IO::AIO::FIEMAP_EXTENT_UNKNOWN>,
1294	C<IO::AIO::FIEMAP_EXTENT_DELALLOC>, C<IO::AIO::FIEMAP_EXTENT_ENCODED>,	1472	C<IO::AIO::FIEMAP_EXTENT_DELALLOC>, C<IO::AIO::FIEMAP_EXTENT_ENCODED>,
1295	C<IO::AIO::FIEMAP_EXTENT_DATA_ENCRYPTED>, C<IO::AIO::FIEMAP_EXTENT_NOT_ALIGNED>,	1473	C<IO::AIO::FIEMAP_EXTENT_DATA_ENCRYPTED>, C<IO::AIO::FIEMAP_EXTENT_NOT_ALIGNED>,
1296	C<IO::AIO::FIEMAP_EXTENT_DATA_INLINE>, C<IO::AIO::FIEMAP_EXTENT_DATA_TAIL>,	1474	C<IO::AIO::FIEMAP_EXTENT_DATA_INLINE>, C<IO::AIO::FIEMAP_EXTENT_DATA_TAIL>,
1297	C<IO::AIO::FIEMAP_EXTENT_UNWRITTEN>, C<IO::AIO::FIEMAP_EXTENT_MERGED> or	1475	C<IO::AIO::FIEMAP_EXTENT_UNWRITTEN>, C<IO::AIO::FIEMAP_EXTENT_MERGED> or
1298	C<IO::AIO::FIEMAP_EXTENT_SHARED>.	1476	C<IO::AIO::FIEMAP_EXTENT_SHARED>.
1299		1477
		1478	At the time of this writing (Linux 3.2), this requets is unreliable unless
		1479	C<$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
1300	=item aio_group $callback->(...)	1483	=item aio_group $callback->(...)
1301		1484
1302	This is a very special aio request: Instead of doing something, it is a	1485	This is a very special aio request: Instead of doing something, it is a
1303	container for other aio requests, which is useful if you want to bundle	1486	container for other aio requests, which is useful if you want to bundle
1304	many requests into a single, composite, request with a definite callback	1487	many requests into a single, composite, request with a definite callback
…		…
1387	aio_stat [$etcdir, "passwd"], sub {	1570	aio_stat [$etcdir, "passwd"], sub {
1388	# yay	1571	# yay
1389	};	1572	};
1390	};	1573	};
1391		1574
1392	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
1393	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,
1394	why it is done asynchronously.	1577	which is why it is done asynchronously.
1395		1578
1396	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
1397	either of the following three request calls:	1580	either of the following three request calls:
1398		1581
1399	aio_lstat "/etc" , sub { ... # pathname as normal string	1582	aio_lstat "/etc" , sub { ... # pathname as normal string
…		…
1419	will still point to the original directory. Most functions accepting a	1602	will still point to the original directory. Most functions accepting a
1420	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
1421	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
1422	string form of the pathname.	1605	string form of the pathname.
1423		1606
1424	So this fucntionality is mainly useful to get some protection against	1607	So this functionality is mainly useful to get some protection against
1425	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
1426	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
1427	(e.g. when stat'ing all files in a directory).	1610	(e.g. when stat'ing all files in a directory).
1428		1611
1429	The following functions implement this working directory abstraction:	1612	The following functions implement this working directory abstraction:
…		…
1442	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
1443	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
1444	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
1445	expected way.	1628	expected way.
1446		1629
1447	If this call isn't available because your OS lacks it or it couldn't be
1448	detected, it will be emulated by calling C<fsync> instead.
1449
1450	=item IO::AIO::CWD	1630	=item IO::AIO::CWD
1451		1631
1452	This is a compiletime constant (object) that represents the process	1632	This is a compiletime constant (object) that represents the process
1453	current working directory.	1633	current working directory.
1454		1634
1455	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
1456	if the pathname would be specified directly, without a directory object,	1636	the pathname would be specified directly, without a directory object. For
1457	e.g., these calls are functionally identical:	1637	example, these calls are functionally identical:
1458		1638
1459	aio_stat "somefile", sub { ... };	1639	aio_stat "somefile", sub { ... };
1460	aio_stat [IO::AIO::CWD, "somefile"], sub { ... };	1640	aio_stat [IO::AIO::CWD, "somefile"], sub { ... };
1461		1641
1462	=back	1642	=back
1463		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.
1464		1653
1465	=head2 IO::AIO::REQ CLASS	1654	=head2 IO::AIO::REQ CLASS
1466		1655
1467	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
1468	called in non-void context.	1657	called in non-void context.
…		…
1646		1835
1647	See C<poll_cb> for an example.	1836	See C<poll_cb> for an example.
1648		1837
1649	=item IO::AIO::poll_cb	1838	=item IO::AIO::poll_cb
1650		1839
1651	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
1652	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
1653	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
1654	reason. Returns immediately when no events are outstanding. The amount of	1846	reason. Returns immediately when no events are outstanding. The amount
1655	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>,
1656	C<IO::AIO::max_poll_time>.	1848	C<IO::AIO::max_poll_time> and C<IO::AIO::max_outstanding>.
1657		1849
1658	If not all requests were processed for whatever reason, the filehandle	1850	If not all requests were processed for whatever reason, the poll file
1659	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
1660	do anything special to have it called later.	1852	don't have to do anything special to have it called later.
1661		1853
1662	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
1663	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
1664	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
1665	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
…		…
1674	poll => 'r', async => 1,	1866	poll => 'r', async => 1,
1675	cb => \&IO::AIO::poll_cb);	1867	cb => \&IO::AIO::poll_cb);
1676		1868
1677	=item IO::AIO::poll_wait	1869	=item IO::AIO::poll_wait
1678		1870
1679	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
1680	phase, wait till the result filehandle becomes ready for reading (simply	1872	requests are outstanding anymore.
1681	does a C<select> on the filehandle. This is useful if you want to	1873
1682	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.
1683		1876
1684	See C<nreqs> for an example.	1877	See C<nreqs> for an example.
1685		1878
1686	=item IO::AIO::poll	1879	=item IO::AIO::poll
1687		1880
…		…
1808		2001
1809	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
1810	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
1811	use an C<aio_group> together with a feed callback.	2004	use an C<aio_group> together with a feed callback.
1812		2005
1813	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
1814	a lot of files, you can write somehting like this:	2007	a lot of files, you can write somehting like this:
1815		2008
1816	IO::AIO::max_outstanding 32;	2009	IO::AIO::max_outstanding 32;
1817		2010
1818	for my $path (...) {	2011	for my $path (...) {
…		…
1858		2051
1859	=back	2052	=back
1860		2053
1861	=head3 MISCELLANEOUS FUNCTIONS	2054	=head3 MISCELLANEOUS FUNCTIONS
1862		2055
1863	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
1864	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.
1865		2060
1866	=over 4	2061	=over 4
1867		2062
1868	=item IO::AIO::sendfile $ofh, $ifh, $offset, $count	2063	=item IO::AIO::sendfile $ofh, $ifh, $offset, $count
1869		2064
…		…
1888	=item IO::AIO::madvise $scalar, $offset, $len, $advice	2083	=item IO::AIO::madvise $scalar, $offset, $len, $advice
1889		2084
1890	Simply calls the C<posix_madvise> function (see its	2085	Simply calls the C<posix_madvise> function (see its
1891	manpage for details). The following advice constants are	2086	manpage for details). The following advice constants are
1892	available: C<IO::AIO::MADV_NORMAL>, C<IO::AIO::MADV_SEQUENTIAL>,	2087	available: C<IO::AIO::MADV_NORMAL>, C<IO::AIO::MADV_SEQUENTIAL>,
1893	C<IO::AIO::MADV_RANDOM>, C<IO::AIO::MADV_WILLNEED>, C<IO::AIO::MADV_DONTNEED>.	2088	C<IO::AIO::MADV_RANDOM>, C<IO::AIO::MADV_WILLNEED>, C<IO::AIO::MADV_DONTNEED>,
		2089	C<IO::AIO::MADV_FREE>.
		2090
		2091	If C<$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>.
1894		2094
1895	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
1896	ENOSYS, otherwise the return value of C<posix_madvise>.	2096	ENOSYS, otherwise the return value of C<posix_madvise>.
1897		2097
1898	=item IO::AIO::mprotect $scalar, $offset, $len, $protect	2098	=item IO::AIO::mprotect $scalar, $offset, $len, $protect
…		…
1900	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
1901	$scalar (see its manpage for details). The following protect	2101	$scalar (see its manpage for details). The following protect
1902	constants are available: C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_READ>,	2102	constants are available: C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_READ>,
1903	C<IO::AIO::PROT_WRITE>, C<IO::AIO::PROT_EXEC>.	2103	C<IO::AIO::PROT_WRITE>, C<IO::AIO::PROT_EXEC>.
1904		2104
		2105	If C<$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
1905	On systems that do not implement C<mprotect>, this function returns	2109	On systems that do not implement C<mprotect>, this function returns
1906	ENOSYS, otherwise the return value of C<mprotect>.	2110	ENOSYS, otherwise the return value of C<mprotect>.
1907		2111
1908	=item IO::AIO::mmap $scalar, $length, $prot, $flags, $fh[, $offset]	2112	=item IO::AIO::mmap $scalar, $length, $prot, $flags, $fh[, $offset]
1909		2113
1910	Memory-maps a file (or anonymous memory range) and attaches it to the	2114	Memory-maps a file (or anonymous memory range) and attaches it to the
1911	given C<$scalar>, which will act like a string scalar.	2115	given C<$scalar>, which will act like a string scalar. Returns true on
		2116	success, and false otherwise.
1912		2117
		2118	The scalar must exist, but its contents do not matter - this means you
		2119	cannot use a nonexistant array or hash element. When in doubt, C<undef>
		2120	the scalar first.
		2121
1913	The only operations allowed on the scalar are C<substr>/C<vec> that don't	2122	The only operations allowed on the mmapped scalar are C<substr>/C<vec>,
1914	change the string length, and most read-only operations such as copying it	2123	which don't change the string length, and most read-only operations such
1915	or searching it with regexes and so on.	2124	as copying it or searching it with regexes and so on.
1916		2125
1917	Anything else is unsafe and will, at best, result in memory leaks.	2126	Anything else is unsafe and will, at best, result in memory leaks.
1918		2127
1919	The memory map associated with the C<$scalar> is automatically removed	2128	The memory map associated with the C<$scalar> is automatically removed
1920	when the C<$scalar> is destroyed, or when the C<IO::AIO::mmap> or	2129	when the C<$scalar> is undef'd or destroyed, or when the C<IO::AIO::mmap>
1921	C<IO::AIO::munmap> functions are called.	2130	or C<IO::AIO::munmap> functions are called on it.
1922		2131
1923	This calls the C<mmap>(2) function internally. See your system's manual	2132	This calls the C<mmap>(2) function internally. See your system's manual
1924	page for details on the C<$length>, C<$prot> and C<$flags> parameters.	2133	page for details on the C<$length>, C<$prot> and C<$flags> parameters.
1925		2134
1926	The C<$length> must be larger than zero and smaller than the actual	2135	The C<$length> must be larger than zero and smaller than the actual
1927	filesize.	2136	filesize.
1928		2137
1929	C<$prot> is a combination of C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_EXEC>,	2138	C<$prot> is a combination of C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_EXEC>,
1930	C<IO::AIO::PROT_READ> and/or C<IO::AIO::PROT_WRITE>,	2139	C<IO::AIO::PROT_READ> and/or C<IO::AIO::PROT_WRITE>,
1931		2140
1932	C<$flags> can be a combination of C<IO::AIO::MAP_SHARED> or	2141	C<$flags> can be a combination of
1933	C<IO::AIO::MAP_PRIVATE>, or a number of system-specific flags (when	2142	C<IO::AIO::MAP_SHARED> or
1934	not available, the are defined as 0): C<IO::AIO::MAP_ANONYMOUS>	2143	C<IO::AIO::MAP_PRIVATE>,
		2144	or a number of system-specific flags (when not available, the are C<0>):
1935	(which is set to C<MAP_ANON> if your system only provides this	2145	C<IO::AIO::MAP_ANONYMOUS> (which is set to C<MAP_ANON> if your system only provides this constant),
1936	constant), C<IO::AIO::MAP_HUGETLB>, C<IO::AIO::MAP_LOCKED>,	2146	C<IO::AIO::MAP_LOCKED>,
1937	C<IO::AIO::MAP_NORESERVE>, C<IO::AIO::MAP_POPULATE> or	2147	C<IO::AIO::MAP_NORESERVE>,
		2148	C<IO::AIO::MAP_POPULATE>,
1938	C<IO::AIO::MAP_NONBLOCK>	2149	C<IO::AIO::MAP_NONBLOCK>,
		2150	C<IO::AIO::MAP_FIXED>,
		2151	C<IO::AIO::MAP_GROWSDOWN>,
		2152	C<IO::AIO::MAP_32BIT>,
		2153	C<IO::AIO::MAP_HUGETLB> or
		2154	C<IO::AIO::MAP_STACK>.
1939		2155
1940	If C<$fh> is C<undef>, then a file descriptor of C<-1> is passed.	2156	If C<$fh> is C<undef>, then a file descriptor of C<-1> is passed.
1941		2157
1942	C<$offset> is the offset from the start of the file - it generally must be	2158	C<$offset> is the offset from the start of the file - it generally must be
1943	a multiple of C<IO::AIO::PAGESIZE> and defaults to C<0>.	2159	a multiple of C<IO::AIO::PAGESIZE> and defaults to C<0>.
…		…
1975		2191
1976	Calls the GNU/Linux C<splice(2)> syscall, if available. If C<$r_off> or	2192	Calls the GNU/Linux C<splice(2)> syscall, if available. If C<$r_off> or
1977	C<$w_off> are C<undef>, then C<NULL> is passed for these, otherwise they	2193	C<$w_off> are C<undef>, then C<NULL> is passed for these, otherwise they
1978	should be the file offset.	2194	should be the file offset.
1979		2195
		2196	C<$r_fh> and C<$w_fh> should not refer to the same file, as splice might
		2197	silently corrupt the data in this case.
		2198
1980	The following symbol flag values are available: C<IO::AIO::SPLICE_F_MOVE>,	2199	The following symbol flag values are available: C<IO::AIO::SPLICE_F_MOVE>,
1981	C<IO::AIO::SPLICE_F_NONBLOCK>, C<IO::AIO::SPLICE_F_MORE> and	2200	C<IO::AIO::SPLICE_F_NONBLOCK>, C<IO::AIO::SPLICE_F_MORE> and
1982	C<IO::AIO::SPLICE_F_GIFT>.	2201	C<IO::AIO::SPLICE_F_GIFT>.
1983		2202
1984	See the C<splice(2)> manpage for details.	2203	See the C<splice(2)> manpage for details.
1985		2204
1986	=item IO::AIO::tee $r_fh, $w_fh, $length, $flags	2205	=item IO::AIO::tee $r_fh, $w_fh, $length, $flags
1987		2206
1988	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
1989	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.
1990		2236
1991	=back	2237	=back
1992		2238
1993	=cut	2239	=cut
1994		2240

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Revision 1.225 by root, Tue Apr 10 05:01:33 2012 UTC vs.
Revision 1.270 by root, Fri Jun 23 03:23:19 2017 UTC