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

Comparing IO-AIO/AIO.pm (file contents):
Revision 1.220 by root, Sun Apr 1 17:46:02 2012 UTC vs.
Revision 1.273 by root, Fri Jun 23 22:33:06 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 = '4.13';	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	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
…		…
413		423
414	=cut	424	=cut
415		425
416	=item aio_seek $fh, $offset, $whence, $callback->($offs)	426	=item aio_seek $fh, $offset, $whence, $callback->($offs)
417		427
418	Seeks the filehandle to the new C<$offset>, similarly to perl'S	428	Seeks the filehandle to the new C<$offset>, similarly to perl's
419	C<sysseek>. The C<$whence> can use the traditional values (C<0> for	429	C<sysseek>. The C<$whence> can use the traditional values (C<0> for
420	C<IO::AIO::SEEK_SET>, C<1> for C<IO::AIO::SEEK_CUR> or C<2> for	430	C<IO::AIO::SEEK_SET>, C<1> for C<IO::AIO::SEEK_CUR> or C<2> for
421	C<IO::AIO::SEEK_END>).	431	C<IO::AIO::SEEK_END>).
422		432
423	The resulting absolute offset will be passed to the callback, or C<-1> in	433	The resulting absolute offset will be passed to the callback, or C<-1> in
…		…
425		435
426	In theory, the C<$whence> constants could be different than the	436	In theory, the C<$whence> constants could be different than the
427	corresponding values from L<Fcntl>, but perl guarantees they are the same,	437	corresponding values from L<Fcntl>, but perl guarantees they are the same,
428	so don't panic.	438	so don't panic.
429		439
		440	As a GNU/Linux (and maybe Solaris) extension, also the constants
		441	C<IO::AIO::SEEK_DATA> and C<IO::AIO::SEEK_HOLE> are available, if they
		442	could be found. No guarantees about suitability for use in C<aio_seek> or
		443	Perl's C<sysseek> can be made though, although I would naively assume they
		444	"just work".
		445
430	=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)	446	=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
431		447
432	=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)	448	=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
433		449
434	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
435	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
436	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
437	error, just like the syscall).	453	error, just like the syscall).
438		454
439	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
440	offset plus the actual number of bytes read.	456	offset plus the actual number of bytes read.
441		457
…		…
499	As native sendfile syscalls (as practically any non-POSIX interface hacked	515	As native sendfile syscalls (as practically any non-POSIX interface hacked
500	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
501	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
502	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,
503	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> -
504	fewre bytes than expected might have been transferred.	520	fewer bytes than expected might have been transferred.
505		521
506		522
507	=item aio_readahead $fh,$offset,$length, $callback->($retval)	523	=item aio_readahead $fh,$offset,$length, $callback->($retval)
508		524
509	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
…		…
513	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
514	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
515	(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
516	file. The current file offset of the file is left unchanged.	532	file. The current file offset of the file is left unchanged.
517		533
518	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
519	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.
520		536
521		537
522	=item aio_stat $fh_or_path, $callback->($status)	538	=item aio_stat $fh_or_path, $callback->($status)
523		539
524	=item aio_lstat $fh, $callback->($status)	540	=item aio_lstat $fh, $callback->($status)
…		…
593	namemax => 255,	609	namemax => 255,
594	frsize => 1024,	610	frsize => 1024,
595	fsid => 1810	611	fsid => 1810
596	}	612	}
597		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
598		698
599	=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status)	699	=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
600		700
601	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
602	and $mtime being undef). Fractional times are supported if the underlying	702	and $mtime being undef). Fractional times are supported if the underlying
…		…
630	=item aio_truncate $fh_or_path, $offset, $callback->($status)	730	=item aio_truncate $fh_or_path, $offset, $callback->($status)
631		731
632	Works like truncate(2) or ftruncate(2).	732	Works like truncate(2) or ftruncate(2).
633		733
634		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), C<FALLOC_FL_ZERO_RANGE>, to zero a range,
		746	C<FALLOC_FL_INSERT_RANGE> to insert a range and C<FALLOC_FL_UNSHARE_RANGE>
		747	to unshare shared blocks (see your L<fallocate(2)> manpage).
		748
		749	The file system block size used by C<fallocate> is presumably the
		750	C<f_bsize> returned by C<statvfs>, but different filesystems and filetypes
		751	can dictate other limitations.
		752
		753	If C<fallocate> isn't available or cannot be emulated (currently no
		754	emulation will be attempted), passes C<-1> and sets C<$!> to C<ENOSYS>.
		755
		756
635	=item aio_chmod $fh_or_path, $mode, $callback->($status)	757	=item aio_chmod $fh_or_path, $mode, $callback->($status)
636		758
637	Works like perl's C<chmod> function.	759	Works like perl's C<chmod> function.
638		760
639		761
…		…
676		798
677		799
678	=item aio_realpath $pathname, $callback->($path)	800	=item aio_realpath $pathname, $callback->($path)
679		801
680	Asynchronously make the path absolute and resolve any symlinks in	802	Asynchronously make the path absolute and resolve any symlinks in
681	C<$path>. The resulting path only consists of directories (Same as	803	C<$path>. The resulting path only consists of directories (same as
682	L<Cwd::realpath>).	804	L<Cwd::realpath>).
683		805
684	This request can be used to get the absolute path of the current working	806	This request can be used to get the absolute path of the current working
685	directory by passing it a path of F<.> (a single dot).	807	directory by passing it a path of F<.> (a single dot).
686		808
687		809
688	=item aio_rename $srcpath, $dstpath, $callback->($status)	810	=item aio_rename $srcpath, $dstpath, $callback->($status)
689		811
690	Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as	812	Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as
691	rename(2) and call the callback with the result code.	813	rename(2) and call the callback with the result code.
		814
		815	On systems that support the AIO::WD working directory abstraction
		816	natively, the case C<[$wd, "."]> as C<$srcpath> is specialcased - instead
		817	of failing, C<rename> is called on the absolute path of C<$wd>.
		818
		819
		820	=item aio_rename2 $srcpath, $dstpath, $flags, $callback->($status)
		821
		822	Basically a version of C<aio_rename> with an additional C<$flags>
		823	argument. Calling this with C<$flags=0> is the same as calling
		824	C<aio_rename>.
		825
		826	Non-zero flags are currently only supported on GNU/Linux systems that
		827	support renameat2. Other systems fail with C<ENOSYS> in this case.
		828
		829	The following constants are available (missing ones are, as usual C<0>),
		830	see renameat2(2) for details:
		831
		832	C<IO::AIO::RENAME_NOREPLACE>, C<IO::AIO::RENAME_EXCHANGE>
		833	and C<IO::AIO::RENAME_WHITEOUT>.
692		834
693		835
694	=item aio_mkdir $pathname, $mode, $callback->($status)	836	=item aio_mkdir $pathname, $mode, $callback->($status)
695		837
696	Asynchronously mkdir (create) a directory and call the callback with	838	Asynchronously mkdir (create) a directory and call the callback with
…		…
700		842
701	=item aio_rmdir $pathname, $callback->($status)	843	=item aio_rmdir $pathname, $callback->($status)
702		844
703	Asynchronously rmdir (delete) a directory and call the callback with the	845	Asynchronously rmdir (delete) a directory and call the callback with the
704	result code.	846	result code.
		847
		848	On systems that support the AIO::WD working directory abstraction
		849	natively, the case C<[$wd, "."]> is specialcased - instead of failing,
		850	C<rmdir> is called on the absolute path of C<$wd>.
705		851
706		852
707	=item aio_readdir $pathname, $callback->($entries)	853	=item aio_readdir $pathname, $callback->($entries)
708		854
709	Unlike the POSIX call of the same name, C<aio_readdir> reads an entire	855	Unlike the POSIX call of the same name, C<aio_readdir> reads an entire
…		…
1074	}	1220	}
1075		1221
1076	=item aio_rmtree $pathname, $callback->($status)	1222	=item aio_rmtree $pathname, $callback->($status)
1077		1223
1078	Delete a directory tree starting (and including) C<$path>, return the	1224	Delete a directory tree starting (and including) C<$path>, return the
1079	status of the final C<rmdir> only. This is a composite request that	1225	status of the final C<rmdir> only. This is a composite request that
1080	uses C<aio_scandir> to recurse into and rmdir directories, and unlink	1226	uses C<aio_scandir> to recurse into and rmdir directories, and unlink
1081	everything else.	1227	everything else.
1082		1228
1083	=cut	1229	=cut
1084		1230
…		…
1105	add $grp $dirgrp;	1251	add $grp $dirgrp;
1106	};	1252	};
1107		1253
1108	$grp	1254	$grp
1109	}	1255	}
		1256
		1257	=item aio_fcntl $fh, $cmd, $arg, $callback->($status)
		1258
		1259	=item aio_ioctl $fh, $request, $buf, $callback->($status)
		1260
		1261	These work just like the C<fcntl> and C<ioctl> built-in functions, except
		1262	they execute asynchronously and pass the return value to the callback.
		1263
		1264	Both calls can be used for a lot of things, some of which make more sense
		1265	to run asynchronously in their own thread, while some others make less
		1266	sense. For example, calls that block waiting for external events, such
		1267	as locking, will also lock down an I/O thread while it is waiting, which
		1268	can deadlock the whole I/O system. At the same time, there might be no
		1269	alternative to using a thread to wait.
		1270
		1271	So in general, you should only use these calls for things that do
		1272	(filesystem) I/O, not for things that wait for other events (network,
		1273	other processes), although if you are careful and know what you are doing,
		1274	you still can.
		1275
		1276	The following constants are available (missing ones are, as usual C<0>):
		1277
		1278	C<F_DUPFD_CLOEXEC>,
		1279
		1280	C<F_OFD_GETLK>, C<F_OFD_SETLK>, C<F_OFD_GETLKW>,
		1281
		1282	C<FIFREEZE>, C<FITHAW>, C<FITRIM>, C<FICLONE>, C<FICLONERANGE>, C<FIDEDUPERANGE>.
		1283
		1284	C<FS_IOC_GETFLAGS>, C<FS_IOC_SETFLAGS>, C<FS_IOC_GETVERSION>, C<FS_IOC_SETVERSION>,
		1285	C<FS_IOC_FIEMAP>.
		1286
		1287	C<FS_IOC_FSGETXATTR>, C<FS_IOC_FSSETXATTR>, C<FS_IOC_SET_ENCRYPTION_POLICY>,
		1288	C<FS_IOC_GET_ENCRYPTION_PWSALT>, C<FS_IOC_GET_ENCRYPTION_POLICY>, C<FS_KEY_DESCRIPTOR_SIZE>.
		1289
		1290	C<FS_SECRM_FL>, C<FS_UNRM_FL>, C<FS_COMPR_FL>, C<FS_SYNC_FL>, C<FS_IMMUTABLE_FL>,
		1291	C<FS_APPEND_FL>, C<FS_NODUMP_FL>, C<FS_NOATIME_FL>, C<FS_DIRTY_FL>,
		1292	C<FS_COMPRBLK_FL>, C<FS_NOCOMP_FL>, C<FS_ENCRYPT_FL>, C<FS_BTREE_FL>,
		1293	C<FS_INDEX_FL>, C<FS_JOURNAL_DATA_FL>, C<FS_NOTAIL_FL>, C<FS_DIRSYNC_FL>, C<FS_TOPDIR_FL>,
		1294	C<FS_FL_USER_MODIFIABLE>.
		1295
		1296	C<FS_XFLAG_REALTIME>, C<FS_XFLAG_PREALLOC>, C<FS_XFLAG_IMMUTABLE>, C<FS_XFLAG_APPEND>,
		1297	C<FS_XFLAG_SYNC>, C<FS_XFLAG_NOATIME>, C<FS_XFLAG_NODUMP>, C<FS_XFLAG_RTINHERIT>,
		1298	C<FS_XFLAG_PROJINHERIT>, C<FS_XFLAG_NOSYMLINKS>, C<FS_XFLAG_EXTSIZE>, C<FS_XFLAG_EXTSZINHERIT>,
		1299	C<FS_XFLAG_NODEFRAG>, C<FS_XFLAG_FILESTREAM>, C<FS_XFLAG_DAX>, C<FS_XFLAG_HASATTR>,
1110		1300
1111	=item aio_sync $callback->($status)	1301	=item aio_sync $callback->($status)
1112		1302
1113	Asynchronously call sync and call the callback when finished.	1303	Asynchronously call sync and call the callback when finished.
1114		1304
…		…
1183	};	1373	};
1184		1374
1185	$grp	1375	$grp
1186	}	1376	}
1187		1377
1188	=item aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)	1378	=item aio_msync $scalar, $offset = 0, $length = undef, flags = MS_SYNC, $callback->($status)
1189		1379
1190	This is a rather advanced IO::AIO call, which only works on mmap(2)ed	1380	This is a rather advanced IO::AIO call, which only works on mmap(2)ed
1191	scalars (see the C<IO::AIO::mmap> function, although it also works on data	1381	scalars (see the C<IO::AIO::mmap> function, although it also works on data
1192	scalars managed by the L<Sys::Mmap> or L<Mmap> modules, note that the	1382	scalars managed by the L<Sys::Mmap> or L<Mmap> modules, note that the
1193	scalar must only be modified in-place while an aio operation is pending on	1383	scalar must only be modified in-place while an aio operation is pending on
…		…
1195		1385
1196	It calls the C<msync> function of your OS, if available, with the memory	1386	It calls the C<msync> function of your OS, if available, with the memory
1197	area starting at C<$offset> in the string and ending C<$length> bytes	1387	area starting at C<$offset> in the string and ending C<$length> bytes
1198	later. If C<$length> is negative, counts from the end, and if C<$length>	1388	later. If C<$length> is negative, counts from the end, and if C<$length>
1199	is C<undef>, then it goes till the end of the string. The flags can be	1389	is C<undef>, then it goes till the end of the string. The flags can be
1200	a combination of C<IO::AIO::MS_ASYNC>, C<IO::AIO::MS_INVALIDATE> and	1390	either C<IO::AIO::MS_ASYNC> or C<IO::AIO::MS_SYNC>, plus an optional
1201	C<IO::AIO::MS_SYNC>.	1391	C<IO::AIO::MS_INVALIDATE>.
1202		1392
1203	=item aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)	1393	=item aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
1204		1394
1205	This is a rather advanced IO::AIO call, which works best on mmap(2)ed	1395	This is a rather advanced IO::AIO call, which works best on mmap(2)ed
1206	scalars.	1396	scalars.
1207		1397
1208	It touches (reads or writes) all memory pages in the specified	1398	It touches (reads or writes) all memory pages in the specified
1209	range inside the scalar. All caveats and parameters are the same	1399	range inside the scalar. All caveats and parameters are the same
1210	as for C<aio_msync>, above, except for flags, which must be either	1400	as for C<aio_msync>, above, except for flags, which must be either
1211	C<0> (which reads all pages and ensures they are instantiated) or	1401	C<0> (which reads all pages and ensures they are instantiated) or
1212	C<IO::AIO::MT_MODIFY>, which modifies the memory page s(by reading and	1402	C<IO::AIO::MT_MODIFY>, which modifies the memory pages (by reading and
1213	writing an octet from it, which dirties the page).	1403	writing an octet from it, which dirties the page).
1214		1404
1215	=item aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status)	1405	=item aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status)
1216		1406
1217	This is a rather advanced IO::AIO call, which works best on mmap(2)ed	1407	This is a rather advanced IO::AIO call, which works best on mmap(2)ed
…		…
1248	documented under L<MISCELLANEOUS FUNCTIONS>.	1438	documented under L<MISCELLANEOUS FUNCTIONS>.
1249		1439
1250	Example: asynchronously lock all current and future pages into memory.	1440	Example: asynchronously lock all current and future pages into memory.
1251		1441
1252	aio_mlockall IO::AIO::MCL_FUTURE;	1442	aio_mlockall IO::AIO::MCL_FUTURE;
		1443
		1444	=item aio_fiemap $fh, $start, $length, $flags, $count, $cb->(\@extents)
		1445
		1446	Queries the extents of the given file (by calling the Linux C<FIEMAP>
		1447	ioctl, see L<http://cvs.schmorp.de/IO-AIO/doc/fiemap.txt> for details). If
		1448	the ioctl is not available on your OS, then this request will fail with
		1449	C<ENOSYS>.
		1450
		1451	C<$start> is the starting offset to query extents for, C<$length> is the
		1452	size of the range to query - if it is C<undef>, then the whole file will
		1453	be queried.
		1454
		1455	C<$flags> is a combination of flags (C<IO::AIO::FIEMAP_FLAG_SYNC> or
		1456	C<IO::AIO::FIEMAP_FLAG_XATTR> - C<IO::AIO::FIEMAP_FLAGS_COMPAT> is also
		1457	exported), and is normally C<0> or C<IO::AIO::FIEMAP_FLAG_SYNC> to query
		1458	the data portion.
		1459
		1460	C<$count> is the maximum number of extent records to return. If it is
		1461	C<undef>, then IO::AIO queries all extents of the range. As a very special
		1462	case, if it is C<0>, then the callback receives the number of extents
		1463	instead of the extents themselves (which is unreliable, see below).
		1464
		1465	If an error occurs, the callback receives no arguments. The special
		1466	C<errno> value C<IO::AIO::EBADR> is available to test for flag errors.
		1467
		1468	Otherwise, the callback receives an array reference with extent
		1469	structures. Each extent structure is an array reference itself, with the
		1470	following members:
		1471
		1472	[$logical, $physical, $length, $flags]
		1473
		1474	Flags is any combination of the following flag values (typically either C<0>
		1475	or C<IO::AIO::FIEMAP_EXTENT_LAST> (1)):
		1476
		1477	C<IO::AIO::FIEMAP_EXTENT_LAST>, C<IO::AIO::FIEMAP_EXTENT_UNKNOWN>,
		1478	C<IO::AIO::FIEMAP_EXTENT_DELALLOC>, C<IO::AIO::FIEMAP_EXTENT_ENCODED>,
		1479	C<IO::AIO::FIEMAP_EXTENT_DATA_ENCRYPTED>, C<IO::AIO::FIEMAP_EXTENT_NOT_ALIGNED>,
		1480	C<IO::AIO::FIEMAP_EXTENT_DATA_INLINE>, C<IO::AIO::FIEMAP_EXTENT_DATA_TAIL>,
		1481	C<IO::AIO::FIEMAP_EXTENT_UNWRITTEN>, C<IO::AIO::FIEMAP_EXTENT_MERGED> or
		1482	C<IO::AIO::FIEMAP_EXTENT_SHARED>.
		1483
		1484	At the time of this writing (Linux 3.2), this requets is unreliable unless
		1485	C<$count> is C<undef>, as the kernel has all sorts of bugs preventing
		1486	it to return all extents of a range for files with large number of
		1487	extents. The code works around all these issues if C<$count> is undef.
1253		1488
1254	=item aio_group $callback->(...)	1489	=item aio_group $callback->(...)
1255		1490
1256	This is a very special aio request: Instead of doing something, it is a	1491	This is a very special aio request: Instead of doing something, it is a
1257	container for other aio requests, which is useful if you want to bundle	1492	container for other aio requests, which is useful if you want to bundle
…		…
1341	aio_stat [$etcdir, "passwd"], sub {	1576	aio_stat [$etcdir, "passwd"], sub {
1342	# yay	1577	# yay
1343	};	1578	};
1344	};	1579	};
1345		1580
1346	That C<aio_wd> is a request and not a normal function shows that creating	1581	The fact that C<aio_wd> is a request and not a normal function shows that
1347	an IO::AIO::WD object is itself a potentially blocking operation, which is	1582	creating an IO::AIO::WD object is itself a potentially blocking operation,
1348	why it is done asynchronously.	1583	which is why it is done asynchronously.
1349		1584
1350	To stat the directory obtained with C<aio_wd> above, one could write	1585	To stat the directory obtained with C<aio_wd> above, one could write
1351	either of the following three request calls:	1586	either of the following three request calls:
1352		1587
1353	aio_lstat "/etc" , sub { ... # pathname as normal string	1588	aio_lstat "/etc" , sub { ... # pathname as normal string
…		…
1373	will still point to the original directory. Most functions accepting a	1608	will still point to the original directory. Most functions accepting a
1374	pathname will use the directory fd on newer systems, and the string on	1609	pathname will use the directory fd on newer systems, and the string on
1375	older systems. Some functions (such as realpath) will always rely on the	1610	older systems. Some functions (such as realpath) will always rely on the
1376	string form of the pathname.	1611	string form of the pathname.
1377		1612
1378	So this fucntionality is mainly useful to get some protection against	1613	So this functionality is mainly useful to get some protection against
1379	C<chdir>, to easily get an absolute path out of a relative path for future	1614	C<chdir>, to easily get an absolute path out of a relative path for future
1380	reference, and to speed up doing many operations in the same directory	1615	reference, and to speed up doing many operations in the same directory
1381	(e.g. when stat'ing all files in a directory).	1616	(e.g. when stat'ing all files in a directory).
1382		1617
1383	The following functions implement this working directory abstraction:	1618	The following functions implement this working directory abstraction:
…		…
1396	passing C<undef> as working directory component of a pathname fails the	1631	passing C<undef> as working directory component of a pathname fails the
1397	request with C<ENOENT>, there is often no need for error checking in the	1632	request with C<ENOENT>, there is often no need for error checking in the
1398	C<aio_wd> callback, as future requests using the value will fail in the	1633	C<aio_wd> callback, as future requests using the value will fail in the
1399	expected way.	1634	expected way.
1400		1635
1401	If this call isn't available because your OS lacks it or it couldn't be
1402	detected, it will be emulated by calling C<fsync> instead.
1403
1404	=item IO::AIO::CWD	1636	=item IO::AIO::CWD
1405		1637
1406	This is a compiletime constant (object) that represents the process	1638	This is a compiletime constant (object) that represents the process
1407	current working directory.	1639	current working directory.
1408		1640
1409	Specifying this object as working directory object for a pathname is as	1641	Specifying this object as working directory object for a pathname is as if
1410	if the pathname would be specified directly, without a directory object,	1642	the pathname would be specified directly, without a directory object. For
1411	e.g., these calls are functionally identical:	1643	example, these calls are functionally identical:
1412		1644
1413	aio_stat "somefile", sub { ... };	1645	aio_stat "somefile", sub { ... };
1414	aio_stat [IO::AIO::CWD, "somefile"], sub { ... };	1646	aio_stat [IO::AIO::CWD, "somefile"], sub { ... };
1415		1647
1416	=back	1648	=back
1417		1649
		1650	To recover the path associated with an IO::AIO::WD object, you can use
		1651	C<aio_realpath>:
		1652
		1653	aio_realpath $wd, sub {
		1654	warn "path is $_[0]\n";
		1655	};
		1656
		1657	Currently, C<aio_statvfs> always, and C<aio_rename> and C<aio_rmdir>
		1658	sometimes, fall back to using an absolue path.
1418		1659
1419	=head2 IO::AIO::REQ CLASS	1660	=head2 IO::AIO::REQ CLASS
1420		1661
1421	All non-aggregate C<aio_*> functions return an object of this class when	1662	All non-aggregate C<aio_*> functions return an object of this class when
1422	called in non-void context.	1663	called in non-void context.
…		…
1600		1841
1601	See C<poll_cb> for an example.	1842	See C<poll_cb> for an example.
1602		1843
1603	=item IO::AIO::poll_cb	1844	=item IO::AIO::poll_cb
1604		1845
1605	Process some outstanding events on the result pipe. You have to call	1846	Process some requests that have reached the result phase (i.e. they have
		1847	been executed but the results are not yet reported). You have to call
		1848	this "regularly" to finish outstanding requests.
		1849
1606	this regularly. Returns C<0> if all events could be processed (or there	1850	Returns C<0> if all events could be processed (or there were no
1607	were no events to process), or C<-1> if it returned earlier for whatever	1851	events to process), or C<-1> if it returned earlier for whatever
1608	reason. Returns immediately when no events are outstanding. The amount of	1852	reason. Returns immediately when no events are outstanding. The amount
1609	events processed depends on the settings of C<IO::AIO::max_poll_req> and	1853	of events processed depends on the settings of C<IO::AIO::max_poll_req>,
1610	C<IO::AIO::max_poll_time>.	1854	C<IO::AIO::max_poll_time> and C<IO::AIO::max_outstanding>.
1611		1855
1612	If not all requests were processed for whatever reason, the filehandle	1856	If not all requests were processed for whatever reason, the poll file
1613	will still be ready when C<poll_cb> returns, so normally you don't have to	1857	descriptor will still be ready when C<poll_cb> returns, so normally you
1614	do anything special to have it called later.	1858	don't have to do anything special to have it called later.
1615		1859
1616	Apart from calling C<IO::AIO::poll_cb> when the event filehandle becomes	1860	Apart from calling C<IO::AIO::poll_cb> when the event filehandle becomes
1617	ready, it can be beneficial to call this function from loops which submit	1861	ready, it can be beneficial to call this function from loops which submit
1618	a lot of requests, to make sure the results get processed when they become	1862	a lot of requests, to make sure the results get processed when they become
1619	available and not just when the loop is finished and the event loop takes	1863	available and not just when the loop is finished and the event loop takes
…		…
1628	poll => 'r', async => 1,	1872	poll => 'r', async => 1,
1629	cb => \&IO::AIO::poll_cb);	1873	cb => \&IO::AIO::poll_cb);
1630		1874
1631	=item IO::AIO::poll_wait	1875	=item IO::AIO::poll_wait
1632		1876
1633	If there are any outstanding requests and none of them in the result	1877	Wait until either at least one request is in the result phase or no
1634	phase, wait till the result filehandle becomes ready for reading (simply	1878	requests are outstanding anymore.
1635	does a C<select> on the filehandle. This is useful if you want to	1879
1636	synchronously wait for some requests to finish).	1880	This is useful if you want to synchronously wait for some requests to
		1881	become ready, without actually handling them.
1637		1882
1638	See C<nreqs> for an example.	1883	See C<nreqs> for an example.
1639		1884
1640	=item IO::AIO::poll	1885	=item IO::AIO::poll
1641		1886
…		…
1762		2007
1763	This is a very bad function to use in interactive programs because it	2008	This is a very bad function to use in interactive programs because it
1764	blocks, and a bad way to reduce concurrency because it is inexact: Better	2009	blocks, and a bad way to reduce concurrency because it is inexact: Better
1765	use an C<aio_group> together with a feed callback.	2010	use an C<aio_group> together with a feed callback.
1766		2011
1767	It's main use is in scripts without an event loop - when you want to stat	2012	Its main use is in scripts without an event loop - when you want to stat
1768	a lot of files, you can write somehting like this:	2013	a lot of files, you can write somehting like this:
1769		2014
1770	IO::AIO::max_outstanding 32;	2015	IO::AIO::max_outstanding 32;
1771		2016
1772	for my $path (...) {	2017	for my $path (...) {
…		…
1812		2057
1813	=back	2058	=back
1814		2059
1815	=head3 MISCELLANEOUS FUNCTIONS	2060	=head3 MISCELLANEOUS FUNCTIONS
1816		2061
1817	IO::AIO implements some functions that might be useful, but are not	2062	IO::AIO implements some functions that are useful when you want to use
1818	asynchronous.	2063	some "Advanced I/O" function not available to in Perl, without going the
		2064	"Asynchronous I/O" route. Many of these have an asynchronous C<aio_*>
		2065	counterpart.
1819		2066
1820	=over 4	2067	=over 4
1821		2068
1822	=item IO::AIO::sendfile $ofh, $ifh, $offset, $count	2069	=item IO::AIO::sendfile $ofh, $ifh, $offset, $count
1823		2070
…		…
1842	=item IO::AIO::madvise $scalar, $offset, $len, $advice	2089	=item IO::AIO::madvise $scalar, $offset, $len, $advice
1843		2090
1844	Simply calls the C<posix_madvise> function (see its	2091	Simply calls the C<posix_madvise> function (see its
1845	manpage for details). The following advice constants are	2092	manpage for details). The following advice constants are
1846	available: C<IO::AIO::MADV_NORMAL>, C<IO::AIO::MADV_SEQUENTIAL>,	2093	available: C<IO::AIO::MADV_NORMAL>, C<IO::AIO::MADV_SEQUENTIAL>,
1847	C<IO::AIO::MADV_RANDOM>, C<IO::AIO::MADV_WILLNEED>, C<IO::AIO::MADV_DONTNEED>.	2094	C<IO::AIO::MADV_RANDOM>, C<IO::AIO::MADV_WILLNEED>,
		2095	C<IO::AIO::MADV_DONTNEED>.
		2096
		2097	If C<$offset> is negative, counts from the end. If C<$length> is negative,
		2098	the remaining length of the C<$scalar> is used. If possible, C<$length>
		2099	will be reduced to fit into the C<$scalar>.
1848		2100
1849	On systems that do not implement C<posix_madvise>, this function returns	2101	On systems that do not implement C<posix_madvise>, this function returns
1850	ENOSYS, otherwise the return value of C<posix_madvise>.	2102	ENOSYS, otherwise the return value of C<posix_madvise>.
1851		2103
1852	=item IO::AIO::mprotect $scalar, $offset, $len, $protect	2104	=item IO::AIO::mprotect $scalar, $offset, $len, $protect
…		…
1854	Simply calls the C<mprotect> function on the preferably AIO::mmap'ed	2106	Simply calls the C<mprotect> function on the preferably AIO::mmap'ed
1855	$scalar (see its manpage for details). The following protect	2107	$scalar (see its manpage for details). The following protect
1856	constants are available: C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_READ>,	2108	constants are available: C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_READ>,
1857	C<IO::AIO::PROT_WRITE>, C<IO::AIO::PROT_EXEC>.	2109	C<IO::AIO::PROT_WRITE>, C<IO::AIO::PROT_EXEC>.
1858		2110
		2111	If C<$offset> is negative, counts from the end. If C<$length> is negative,
		2112	the remaining length of the C<$scalar> is used. If possible, C<$length>
		2113	will be reduced to fit into the C<$scalar>.
		2114
1859	On systems that do not implement C<mprotect>, this function returns	2115	On systems that do not implement C<mprotect>, this function returns
1860	ENOSYS, otherwise the return value of C<mprotect>.	2116	ENOSYS, otherwise the return value of C<mprotect>.
1861		2117
1862	=item IO::AIO::mmap $scalar, $length, $prot, $flags, $fh[, $offset]	2118	=item IO::AIO::mmap $scalar, $length, $prot, $flags, $fh[, $offset]
1863		2119
1864	Memory-maps a file (or anonymous memory range) and attaches it to the	2120	Memory-maps a file (or anonymous memory range) and attaches it to the
1865	given C<$scalar>, which will act like a string scalar.	2121	given C<$scalar>, which will act like a string scalar. Returns true on
		2122	success, and false otherwise.
1866		2123
		2124	The scalar must exist, but its contents do not matter - this means you
		2125	cannot use a nonexistant array or hash element. When in doubt, C<undef>
		2126	the scalar first.
		2127
1867	The only operations allowed on the scalar are C<substr>/C<vec> that don't	2128	The only operations allowed on the mmapped scalar are C<substr>/C<vec>,
1868	change the string length, and most read-only operations such as copying it	2129	which don't change the string length, and most read-only operations such
1869	or searching it with regexes and so on.	2130	as copying it or searching it with regexes and so on.
1870		2131
1871	Anything else is unsafe and will, at best, result in memory leaks.	2132	Anything else is unsafe and will, at best, result in memory leaks.
1872		2133
1873	The memory map associated with the C<$scalar> is automatically removed	2134	The memory map associated with the C<$scalar> is automatically removed
1874	when the C<$scalar> is destroyed, or when the C<IO::AIO::mmap> or	2135	when the C<$scalar> is undef'd or destroyed, or when the C<IO::AIO::mmap>
1875	C<IO::AIO::munmap> functions are called.	2136	or C<IO::AIO::munmap> functions are called on it.
1876		2137
1877	This calls the C<mmap>(2) function internally. See your system's manual	2138	This calls the C<mmap>(2) function internally. See your system's manual
1878	page for details on the C<$length>, C<$prot> and C<$flags> parameters.	2139	page for details on the C<$length>, C<$prot> and C<$flags> parameters.
1879		2140
1880	The C<$length> must be larger than zero and smaller than the actual	2141	The C<$length> must be larger than zero and smaller than the actual
1881	filesize.	2142	filesize.
1882		2143
1883	C<$prot> is a combination of C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_EXEC>,	2144	C<$prot> is a combination of C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_EXEC>,
1884	C<IO::AIO::PROT_READ> and/or C<IO::AIO::PROT_WRITE>,	2145	C<IO::AIO::PROT_READ> and/or C<IO::AIO::PROT_WRITE>,
1885		2146
1886	C<$flags> can be a combination of C<IO::AIO::MAP_SHARED> or	2147	C<$flags> can be a combination of
1887	C<IO::AIO::MAP_PRIVATE>, or a number of system-specific flags (when	2148	C<IO::AIO::MAP_SHARED> or
1888	not available, the are defined as 0): C<IO::AIO::MAP_ANONYMOUS>	2149	C<IO::AIO::MAP_PRIVATE>,
		2150	or a number of system-specific flags (when not available, the are C<0>):
1889	(which is set to C<MAP_ANON> if your system only provides this	2151	C<IO::AIO::MAP_ANONYMOUS> (which is set to C<MAP_ANON> if your system only provides this constant),
1890	constant), C<IO::AIO::MAP_HUGETLB>, C<IO::AIO::MAP_LOCKED>,	2152	C<IO::AIO::MAP_LOCKED>,
1891	C<IO::AIO::MAP_NORESERVE>, C<IO::AIO::MAP_POPULATE> or	2153	C<IO::AIO::MAP_NORESERVE>,
		2154	C<IO::AIO::MAP_POPULATE>,
1892	C<IO::AIO::MAP_NONBLOCK>	2155	C<IO::AIO::MAP_NONBLOCK>,
		2156	C<IO::AIO::MAP_FIXED>,
		2157	C<IO::AIO::MAP_GROWSDOWN>,
		2158	C<IO::AIO::MAP_32BIT>,
		2159	C<IO::AIO::MAP_HUGETLB> or
		2160	C<IO::AIO::MAP_STACK>.
1893		2161
1894	If C<$fh> is C<undef>, then a file descriptor of C<-1> is passed.	2162	If C<$fh> is C<undef>, then a file descriptor of C<-1> is passed.
1895		2163
1896	C<$offset> is the offset from the start of the file - it generally must be	2164	C<$offset> is the offset from the start of the file - it generally must be
1897	a multiple of C<IO::AIO::PAGESIZE> and defaults to C<0>.	2165	a multiple of C<IO::AIO::PAGESIZE> and defaults to C<0>.
…		…
1922		2190
1923	Calls the C<munlockall> function.	2191	Calls the C<munlockall> function.
1924		2192
1925	On systems that do not implement C<munlockall>, this function returns	2193	On systems that do not implement C<munlockall>, this function returns
1926	ENOSYS, otherwise the return value of C<munlockall>.	2194	ENOSYS, otherwise the return value of C<munlockall>.
		2195
		2196	=item IO::AIO::splice $r_fh, $r_off, $w_fh, $w_off, $length, $flags
		2197
		2198	Calls the GNU/Linux C<splice(2)> syscall, if available. If C<$r_off> or
		2199	C<$w_off> are C<undef>, then C<NULL> is passed for these, otherwise they
		2200	should be the file offset.
		2201
		2202	C<$r_fh> and C<$w_fh> should not refer to the same file, as splice might
		2203	silently corrupt the data in this case.
		2204
		2205	The following symbol flag values are available: C<IO::AIO::SPLICE_F_MOVE>,
		2206	C<IO::AIO::SPLICE_F_NONBLOCK>, C<IO::AIO::SPLICE_F_MORE> and
		2207	C<IO::AIO::SPLICE_F_GIFT>.
		2208
		2209	See the C<splice(2)> manpage for details.
		2210
		2211	=item IO::AIO::tee $r_fh, $w_fh, $length, $flags
		2212
		2213	Calls the GNU/Linux C<tee(2)> syscall, see its manpage and the
		2214	description for C<IO::AIO::splice> above for details.
		2215
		2216	=item $actual_size = IO::AIO::pipesize $r_fh[, $new_size]
		2217
		2218	Attempts to query or change the pipe buffer size. Obviously works only
		2219	on pipes, and currently works only on GNU/Linux systems, and fails with
		2220	C<-1>/C<ENOSYS> everywhere else. If anybody knows how to influence pipe buffer
		2221	size on other systems, drop me a note.
		2222
		2223	=item ($rfh, $wfh) = IO::AIO::pipe2 [$flags]
		2224
		2225	This is a direct interface to the Linux L<pipe2(2)> system call. If
		2226	C<$flags> is missing or C<0>, then this should be the same as a call to
		2227	perl's built-in C<pipe> function and create a new pipe, and works on
		2228	systems that lack the pipe2 syscall. On win32, this case invokes C<_pipe
		2229	(..., 4096, O_BINARY)>.
		2230
		2231	If C<$flags> is non-zero, it tries to invoke the pipe2 system call with
		2232	the given flags (Linux 2.6.27, glibc 2.9).
		2233
		2234	On success, the read and write file handles are returned.
		2235
		2236	On error, nothing will be returned. If the pipe2 syscall is missing and
		2237	C<$flags> is non-zero, fails with C<ENOSYS>.
		2238
		2239	Please refer to L<pipe2(2)> for more info on the C<$flags>, but at the
		2240	time of this writing, C<IO::AIO::O_CLOEXEC>, C<IO::AIO::O_NONBLOCK> and
		2241	C<IO::AIO::O_DIRECT> (Linux 3.4, for packet-based pipes) were supported.
1927		2242
1928	=back	2243	=back
1929		2244
1930	=cut	2245	=cut
1931		2246

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Comparing IO-AIO/AIO.pm (file contents): Revision 1.220 by root, Sun Apr 1 17:46:02 2012 UTC vs. Revision 1.273 by root, Fri Jun 23 22:33:06 2017 UTC

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Comparing IO-AIO/AIO.pm (file contents):
Revision 1.220 by root, Sun Apr 1 17:46:02 2012 UTC vs.
Revision 1.273 by root, Fri Jun 23 22:33:06 2017 UTC