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

Comparing IO-AIO/AIO.pm (file contents):
Revision 1.229 by root, Wed Jul 25 16:32:30 2012 UTC vs.
Revision 1.277 by root, Fri Sep 22 12:17:49 2017 UTC

…		…
1	=head1 NAME	1	=head1 NAME
2		2
3	IO::AIO - Asynchronous Input/Output	3	IO::AIO - Asynchronous/Advanced Input/Output
4		4
5	=head1 SYNOPSIS	5	=head1 SYNOPSIS
6		6
7	use IO::AIO;	7	use IO::AIO;
8		8
58	not well-supported or restricted (GNU/Linux doesn't allow them on normal	58	not well-supported or restricted (GNU/Linux doesn't allow them on normal
59	files currently, for example), and they would only support aio_read and	59	files currently, for example), and they would only support aio_read and
60	aio_write, so the remaining functionality would have to be implemented	60	aio_write, so the remaining functionality would have to be implemented
61	using threads anyway.	61	using threads anyway.
62		62
		63	In addition to asynchronous I/O, this module also exports some rather
		64	arcane interfaces, such as C<madvise> or linux's C<splice> system call,
		65	which is why the C<A> in C<AIO> can also mean I<advanced>.
		66
63	Although the module will work in the presence of other (Perl-) threads,	67	Although the module will work in the presence of other (Perl-) threads,
64	it is currently not reentrant in any way, so use appropriate locking	68	it is currently not reentrant in any way, so use appropriate locking
65	yourself, always call C<poll_cb> from within the same thread, or never	69	yourself, always call C<poll_cb> from within the same thread, or never
66	call C<poll_cb> (or other C<aio_> functions) recursively.	70	call C<poll_cb> (or other C<aio_> functions) recursively.
67		71
68	=head2 EXAMPLE	72	=head2 EXAMPLE
69		73
70	This is a simple example that uses the EV module and loads	74	This is a simple example that uses the EV module and loads
71	F</etc/passwd> asynchronously:	75	F</etc/passwd> asynchronously:
72		76
73	use Fcntl;
74	use EV;	77	use EV;
75	use IO::AIO;	78	use IO::AIO;
76		79
77	# register the IO::AIO callback with EV	80	# register the IO::AIO callback with EV
78	my $aio_w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb;	81	my $aio_w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb;
…		…
95		98
96	# file contents now in $contents	99	# file contents now in $contents
97	print $contents;	100	print $contents;
98		101
99	# exit event loop and program	102	# exit event loop and program
100	EV::unloop;	103	EV::break;
101	};	104	};
102	};	105	};
103		106
104	# possibly queue up other requests, or open GUI windows,	107	# possibly queue up other requests, or open GUI windows,
105	# check for sockets etc. etc.	108	# check for sockets etc. etc.
106		109
107	# process events as long as there are some:	110	# process events as long as there are some:
108	EV::loop;	111	EV::run;
109		112
110	=head1 REQUEST ANATOMY AND LIFETIME	113	=head1 REQUEST ANATOMY AND LIFETIME
111		114
112	Every C<aio_*> function creates a request. which is a C data structure not	115	Every C<aio_*> function creates a request. which is a C data structure not
113	directly visible to Perl.	116	directly visible to Perl.
…		…
168	use common::sense;	171	use common::sense;
169		172
170	use base 'Exporter';	173	use base 'Exporter';
171		174
172	BEGIN {	175	BEGIN {
173	our $VERSION = '4.15';	176	our $VERSION = 4.35;
174		177
175	our @AIO_REQ = qw(aio_sendfile aio_seek aio_read aio_write aio_open aio_close	178	our @AIO_REQ = qw(aio_sendfile aio_seek aio_read aio_write aio_open aio_close
176	aio_stat aio_lstat aio_unlink aio_rmdir aio_readdir aio_readdirx	179	aio_stat aio_lstat aio_unlink aio_rmdir aio_readdir aio_readdirx
177	aio_scandir aio_symlink aio_readlink aio_realpath aio_sync	180	aio_scandir aio_symlink aio_readlink aio_realpath aio_fcntl aio_ioctl
178	aio_fsync aio_syncfs aio_fdatasync aio_sync_file_range aio_fallocate	181	aio_sync aio_fsync aio_syncfs aio_fdatasync aio_sync_file_range
179	aio_pathsync aio_readahead aio_fiemap	182	aio_pathsync aio_readahead aio_fiemap aio_allocate
180	aio_rename aio_link aio_move aio_copy aio_group	183	aio_rename aio_rename2 aio_link aio_move aio_copy aio_group
181	aio_nop aio_mknod aio_load aio_rmtree aio_mkdir aio_chown	184	aio_nop aio_mknod aio_load aio_rmtree aio_mkdir aio_chown
182	aio_chmod aio_utime aio_truncate	185	aio_chmod aio_utime aio_truncate
183	aio_msync aio_mtouch aio_mlock aio_mlockall	186	aio_msync aio_mtouch aio_mlock aio_mlockall
184	aio_statvfs	187	aio_statvfs
185	aio_wd);	188	aio_wd);
…		…
202		205
203	=head1 FUNCTIONS	206	=head1 FUNCTIONS
204		207
205	=head2 QUICK OVERVIEW	208	=head2 QUICK OVERVIEW
206		209
207	This section simply lists the prototypes of the most important functions	210	This section simply lists the prototypes most of the functions for
208	for quick reference. See the following sections for function-by-function	211	quick reference. See the following sections for function-by-function
209	documentation.	212	documentation.
210		213
211	aio_wd $pathname, $callback->($wd)	214	aio_wd $pathname, $callback->($wd)
212	aio_open $pathname, $flags, $mode, $callback->($fh)	215	aio_open $pathname, $flags, $mode, $callback->($fh)
213	aio_close $fh, $callback->($status)	216	aio_close $fh, $callback->($status)
…		…
222	aio_utime $fh_or_path, $atime, $mtime, $callback->($status)	225	aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
223	aio_chown $fh_or_path, $uid, $gid, $callback->($status)	226	aio_chown $fh_or_path, $uid, $gid, $callback->($status)
224	aio_chmod $fh_or_path, $mode, $callback->($status)	227	aio_chmod $fh_or_path, $mode, $callback->($status)
225	aio_truncate $fh_or_path, $offset, $callback->($status)	228	aio_truncate $fh_or_path, $offset, $callback->($status)
226	aio_allocate $fh, $mode, $offset, $len, $callback->($status)	229	aio_allocate $fh, $mode, $offset, $len, $callback->($status)
		230	aio_fiemap $fh, $start, $length, $flags, $count, $cb->(\@extents)
227	aio_unlink $pathname, $callback->($status)	231	aio_unlink $pathname, $callback->($status)
228	aio_mknod $pathname, $mode, $dev, $callback->($status)	232	aio_mknod $pathname, $mode, $dev, $callback->($status)
229	aio_link $srcpath, $dstpath, $callback->($status)	233	aio_link $srcpath, $dstpath, $callback->($status)
230	aio_symlink $srcpath, $dstpath, $callback->($status)	234	aio_symlink $srcpath, $dstpath, $callback->($status)
231	aio_readlink $pathname, $callback->($link)	235	aio_readlink $pathname, $callback->($link)
232	aio_realpath $pathname, $callback->($link)	236	aio_realpath $pathname, $callback->($path)
233	aio_rename $srcpath, $dstpath, $callback->($status)	237	aio_rename $srcpath, $dstpath, $callback->($status)
		238	aio_rename2 $srcpath, $dstpath, $flags, $callback->($status)
234	aio_mkdir $pathname, $mode, $callback->($status)	239	aio_mkdir $pathname, $mode, $callback->($status)
235	aio_rmdir $pathname, $callback->($status)	240	aio_rmdir $pathname, $callback->($status)
236	aio_readdir $pathname, $callback->($entries)	241	aio_readdir $pathname, $callback->($entries)
237	aio_readdirx $pathname, $flags, $callback->($entries, $flags)	242	aio_readdirx $pathname, $flags, $callback->($entries, $flags)
238	IO::AIO::READDIR_DENTS IO::AIO::READDIR_DIRS_FIRST	243	IO::AIO::READDIR_DENTS IO::AIO::READDIR_DIRS_FIRST
…		…
240	aio_scandir $pathname, $maxreq, $callback->($dirs, $nondirs)	245	aio_scandir $pathname, $maxreq, $callback->($dirs, $nondirs)
241	aio_load $pathname, $data, $callback->($status)	246	aio_load $pathname, $data, $callback->($status)
242	aio_copy $srcpath, $dstpath, $callback->($status)	247	aio_copy $srcpath, $dstpath, $callback->($status)
243	aio_move $srcpath, $dstpath, $callback->($status)	248	aio_move $srcpath, $dstpath, $callback->($status)
244	aio_rmtree $pathname, $callback->($status)	249	aio_rmtree $pathname, $callback->($status)
		250	aio_fcntl $fh, $cmd, $arg, $callback->($status)
		251	aio_ioctl $fh, $request, $buf, $callback->($status)
245	aio_sync $callback->($status)	252	aio_sync $callback->($status)
246	aio_syncfs $fh, $callback->($status)	253	aio_syncfs $fh, $callback->($status)
247	aio_fsync $fh, $callback->($status)	254	aio_fsync $fh, $callback->($status)
248	aio_fdatasync $fh, $callback->($status)	255	aio_fdatasync $fh, $callback->($status)
249	aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status)	256	aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status)
250	aio_pathsync $pathname, $callback->($status)	257	aio_pathsync $pathname, $callback->($status)
251	aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)	258	aio_msync $scalar, $offset = 0, $length = undef, flags = MS_SYNC, $callback->($status)
252	aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)	259	aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
253	aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status)	260	aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status)
254	aio_mlockall $flags, $callback->($status)	261	aio_mlockall $flags, $callback->($status)
255	aio_group $callback->(...)	262	aio_group $callback->(...)
256	aio_nop $callback->()	263	aio_nop $callback->()
…		…
270	IO::AIO::idle_timeout $seconds	277	IO::AIO::idle_timeout $seconds
271	IO::AIO::max_outstanding $maxreqs	278	IO::AIO::max_outstanding $maxreqs
272	IO::AIO::nreqs	279	IO::AIO::nreqs
273	IO::AIO::nready	280	IO::AIO::nready
274	IO::AIO::npending	281	IO::AIO::npending
		282	IO::AIO::min_fdlimit $nfd;
275		283
276	IO::AIO::sendfile $ofh, $ifh, $offset, $count	284	IO::AIO::sendfile $ofh, $ifh, $offset, $count
277	IO::AIO::fadvise $fh, $offset, $len, $advice	285	IO::AIO::fadvise $fh, $offset, $len, $advice
278	IO::AIO::mmap $scalar, $length, $prot, $flags[, $fh[, $offset]]	286	IO::AIO::mmap $scalar, $length, $prot, $flags[, $fh[, $offset]]
279	IO::AIO::munmap $scalar	287	IO::AIO::munmap $scalar
…		…
361		369
362		370
363	=item aio_open $pathname, $flags, $mode, $callback->($fh)	371	=item aio_open $pathname, $flags, $mode, $callback->($fh)
364		372
365	Asynchronously open or create a file and call the callback with a newly	373	Asynchronously open or create a file and call the callback with a newly
366	created filehandle for the file.	374	created filehandle for the file (or C<undef> in case of an error).
367		375
368	The pathname passed to C<aio_open> must be absolute. See API NOTES, above,	376	The pathname passed to C<aio_open> must be absolute. See API NOTES, above,
369	for an explanation.	377	for an explanation.
370		378
371	The C<$flags> argument is a bitmask. See the C<Fcntl> module for a	379	The C<$flags> argument is a bitmask. See the C<Fcntl> module for a
…		…
394	following POSIX and non-POSIX constants are available (missing ones on	402	following POSIX and non-POSIX constants are available (missing ones on
395	your system are, as usual, C<0>):	403	your system are, as usual, C<0>):
396		404
397	C<O_ASYNC>, C<O_DIRECT>, C<O_NOATIME>, C<O_CLOEXEC>, C<O_NOCTTY>, C<O_NOFOLLOW>,	405	C<O_ASYNC>, C<O_DIRECT>, C<O_NOATIME>, C<O_CLOEXEC>, C<O_NOCTTY>, C<O_NOFOLLOW>,
398	C<O_NONBLOCK>, C<O_EXEC>, C<O_SEARCH>, C<O_DIRECTORY>, C<O_DSYNC>,	406	C<O_NONBLOCK>, C<O_EXEC>, C<O_SEARCH>, C<O_DIRECTORY>, C<O_DSYNC>,
399	C<O_RSYNC>, C<O_SYNC> and C<O_TTY_INIT>.	407	C<O_RSYNC>, C<O_SYNC>, C<O_PATH>, C<O_TMPFILE>, and C<O_TTY_INIT>.
400		408
401		409
402	=item aio_close $fh, $callback->($status)	410	=item aio_close $fh, $callback->($status)
403		411
404	Asynchronously close a file and call the callback with the result	412	Asynchronously close a file and call the callback with the result
…		…
439	=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)	447	=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
440		448
441	=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)	449	=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
442		450
443	Reads or writes C<$length> bytes from or to the specified C<$fh> and	451	Reads or writes C<$length> bytes from or to the specified C<$fh> and
444	C<$offset> into the scalar given by C<$data> and offset C<$dataoffset>	452	C<$offset> into the scalar given by C<$data> and offset C<$dataoffset> and
445	and calls the callback without the actual number of bytes read (or -1 on	453	calls the callback with the actual number of bytes transferred (or -1 on
446	error, just like the syscall).	454	error, just like the syscall).
447		455
448	C<aio_read> will, like C<sysread>, shrink or grow the C<$data> scalar to	456	C<aio_read> will, like C<sysread>, shrink or grow the C<$data> scalar to
449	offset plus the actual number of bytes read.	457	offset plus the actual number of bytes read.
450		458
…		…
508	As native sendfile syscalls (as practically any non-POSIX interface hacked	516	As native sendfile syscalls (as practically any non-POSIX interface hacked
509	together in a hurry to improve benchmark numbers) tend to be rather buggy	517	together in a hurry to improve benchmark numbers) tend to be rather buggy
510	on many systems, this implementation tries to work around some known bugs	518	on many systems, this implementation tries to work around some known bugs
511	in Linux and FreeBSD kernels (probably others, too), but that might fail,	519	in Linux and FreeBSD kernels (probably others, too), but that might fail,
512	so you really really should check the return value of C<aio_sendfile> -	520	so you really really should check the return value of C<aio_sendfile> -
513	fewre bytes than expected might have been transferred.	521	fewer bytes than expected might have been transferred.
514		522
515		523
516	=item aio_readahead $fh,$offset,$length, $callback->($retval)	524	=item aio_readahead $fh,$offset,$length, $callback->($retval)
517		525
518	C<aio_readahead> populates the page cache with data from a file so that	526	C<aio_readahead> populates the page cache with data from a file so that
…		…
522	whole pages, so that offset is effectively rounded down to a page boundary	530	whole pages, so that offset is effectively rounded down to a page boundary
523	and bytes are read up to the next page boundary greater than or equal to	531	and bytes are read up to the next page boundary greater than or equal to
524	(off-set+length). C<aio_readahead> does not read beyond the end of the	532	(off-set+length). C<aio_readahead> does not read beyond the end of the
525	file. The current file offset of the file is left unchanged.	533	file. The current file offset of the file is left unchanged.
526		534
527	If that syscall doesn't exist (likely if your OS isn't Linux) it will be	535	If that syscall doesn't exist (likely if your kernel isn't Linux) it will
528	emulated by simply reading the data, which would have a similar effect.	536	be emulated by simply reading the data, which would have a similar effect.
529		537
530		538
531	=item aio_stat $fh_or_path, $callback->($status)	539	=item aio_stat $fh_or_path, $callback->($status)
532		540
533	=item aio_lstat $fh, $callback->($status)	541	=item aio_lstat $fh, $callback->($status)
…		…
602	namemax => 255,	610	namemax => 255,
603	frsize => 1024,	611	frsize => 1024,
604	fsid => 1810	612	fsid => 1810
605	}	613	}
606		614
		615	Here is a (likely partial - send me updates!) list of fsid values used by
		616	Linux - it is safe to hardcode these when C<$^O> is C<linux>:
		617
		618	0x0000adf5 adfs
		619	0x0000adff affs
		620	0x5346414f afs
		621	0x09041934 anon-inode filesystem
		622	0x00000187 autofs
		623	0x42465331 befs
		624	0x1badface bfs
		625	0x42494e4d binfmt_misc
		626	0x9123683e btrfs
		627	0x0027e0eb cgroupfs
		628	0xff534d42 cifs
		629	0x73757245 coda
		630	0x012ff7b7 coh
		631	0x28cd3d45 cramfs
		632	0x453dcd28 cramfs-wend (wrong endianness)
		633	0x64626720 debugfs
		634	0x00001373 devfs
		635	0x00001cd1 devpts
		636	0x0000f15f ecryptfs
		637	0x00414a53 efs
		638	0x0000137d ext
		639	0x0000ef53 ext2/ext3/ext4
		640	0x0000ef51 ext2
		641	0xf2f52010 f2fs
		642	0x00004006 fat
		643	0x65735546 fuseblk
		644	0x65735543 fusectl
		645	0x0bad1dea futexfs
		646	0x01161970 gfs2
		647	0x47504653 gpfs
		648	0x00004244 hfs
		649	0xf995e849 hpfs
		650	0x00c0ffee hostfs
		651	0x958458f6 hugetlbfs
		652	0x2bad1dea inotifyfs
		653	0x00009660 isofs
		654	0x000072b6 jffs2
		655	0x3153464a jfs
		656	0x6b414653 k-afs
		657	0x0bd00bd0 lustre
		658	0x0000137f minix
		659	0x0000138f minix 30 char names
		660	0x00002468 minix v2
		661	0x00002478 minix v2 30 char names
		662	0x00004d5a minix v3
		663	0x19800202 mqueue
		664	0x00004d44 msdos
		665	0x0000564c novell
		666	0x00006969 nfs
		667	0x6e667364 nfsd
		668	0x00003434 nilfs
		669	0x5346544e ntfs
		670	0x00009fa1 openprom
		671	0x7461636F ocfs2
		672	0x00009fa0 proc
		673	0x6165676c pstorefs
		674	0x0000002f qnx4
		675	0x68191122 qnx6
		676	0x858458f6 ramfs
		677	0x52654973 reiserfs
		678	0x00007275 romfs
		679	0x67596969 rpc_pipefs
		680	0x73636673 securityfs
		681	0xf97cff8c selinux
		682	0x0000517b smb
		683	0x534f434b sockfs
		684	0x73717368 squashfs
		685	0x62656572 sysfs
		686	0x012ff7b6 sysv2
		687	0x012ff7b5 sysv4
		688	0x01021994 tmpfs
		689	0x15013346 udf
		690	0x00011954 ufs
		691	0x54190100 ufs byteswapped
		692	0x00009fa2 usbdevfs
		693	0x01021997 v9fs
		694	0xa501fcf5 vxfs
		695	0xabba1974 xenfs
		696	0x012ff7b4 xenix
		697	0x58465342 xfs
		698	0x012fd16d xia
607		699
608	=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status)	700	=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
609		701
610	Works like perl's C<utime> function (including the special case of $atime	702	Works like perl's C<utime> function (including the special case of $atime
611	and $mtime being undef). Fractional times are supported if the underlying	703	and $mtime being undef). Fractional times are supported if the underlying
…		…
641	Works like truncate(2) or ftruncate(2).	733	Works like truncate(2) or ftruncate(2).
642		734
643		735
644	=item aio_allocate $fh, $mode, $offset, $len, $callback->($status)	736	=item aio_allocate $fh, $mode, $offset, $len, $callback->($status)
645		737
646	Allocates or freed disk space according to the C<$mode> argument. See the	738	Allocates or frees disk space according to the C<$mode> argument. See the
647	linux C<fallocate> docuemntation for details.	739	linux C<fallocate> documentation for details.
648		740
649	C<$mode> can currently be C<0> or C<IO::AIO::FALLOC_FL_KEEP_SIZE>	741	C<$mode> is usually C<0> or C<IO::AIO::FALLOC_FL_KEEP_SIZE> to allocate
650	to allocate space, or C<IO::AIO::FALLOC_FL_PUNCH_HOLE \|	742	space, or C<IO::AIO::FALLOC_FL_PUNCH_HOLE \| IO::AIO::FALLOC_FL_KEEP_SIZE>,
651	IO::AIO::FALLOC_FL_KEEP_SIZE>, to deallocate a file range.	743	to deallocate a file range.
		744
		745	IO::AIO also supports C<FALLOC_FL_COLLAPSE_RANGE>, to remove a range
		746	(without leaving a hole), C<FALLOC_FL_ZERO_RANGE>, to zero a range,
		747	C<FALLOC_FL_INSERT_RANGE> to insert a range and C<FALLOC_FL_UNSHARE_RANGE>
		748	to unshare shared blocks (see your L<fallocate(2)> manpage).
652		749
653	The file system block size used by C<fallocate> is presumably the	750	The file system block size used by C<fallocate> is presumably the
654	C<f_bsize> returned by C<statvfs>.	751	C<f_bsize> returned by C<statvfs>, but different filesystems and filetypes
		752	can dictate other limitations.
655		753
656	If C<fallocate> isn't available or cannot be emulated (currently no	754	If C<fallocate> isn't available or cannot be emulated (currently no
657	emulation will be attempted), passes C<-1> and sets C<$!> to C<ENOSYS>.	755	emulation will be attempted), passes C<-1> and sets C<$!> to C<ENOSYS>.
658		756
659		757
…		…
701		799
702		800
703	=item aio_realpath $pathname, $callback->($path)	801	=item aio_realpath $pathname, $callback->($path)
704		802
705	Asynchronously make the path absolute and resolve any symlinks in	803	Asynchronously make the path absolute and resolve any symlinks in
706	C<$path>. The resulting path only consists of directories (Same as	804	C<$path>. The resulting path only consists of directories (same as
707	L<Cwd::realpath>).	805	L<Cwd::realpath>).
708		806
709	This request can be used to get the absolute path of the current working	807	This request can be used to get the absolute path of the current working
710	directory by passing it a path of F<.> (a single dot).	808	directory by passing it a path of F<.> (a single dot).
711		809
712		810
713	=item aio_rename $srcpath, $dstpath, $callback->($status)	811	=item aio_rename $srcpath, $dstpath, $callback->($status)
714		812
715	Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as	813	Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as
716	rename(2) and call the callback with the result code.	814	rename(2) and call the callback with the result code.
		815
		816	On systems that support the AIO::WD working directory abstraction
		817	natively, the case C<[$wd, "."]> as C<$srcpath> is specialcased - instead
		818	of failing, C<rename> is called on the absolute path of C<$wd>.
		819
		820
		821	=item aio_rename2 $srcpath, $dstpath, $flags, $callback->($status)
		822
		823	Basically a version of C<aio_rename> with an additional C<$flags>
		824	argument. Calling this with C<$flags=0> is the same as calling
		825	C<aio_rename>.
		826
		827	Non-zero flags are currently only supported on GNU/Linux systems that
		828	support renameat2. Other systems fail with C<ENOSYS> in this case.
		829
		830	The following constants are available (missing ones are, as usual C<0>),
		831	see renameat2(2) for details:
		832
		833	C<IO::AIO::RENAME_NOREPLACE>, C<IO::AIO::RENAME_EXCHANGE>
		834	and C<IO::AIO::RENAME_WHITEOUT>.
717		835
718		836
719	=item aio_mkdir $pathname, $mode, $callback->($status)	837	=item aio_mkdir $pathname, $mode, $callback->($status)
720		838
721	Asynchronously mkdir (create) a directory and call the callback with	839	Asynchronously mkdir (create) a directory and call the callback with
…		…
725		843
726	=item aio_rmdir $pathname, $callback->($status)	844	=item aio_rmdir $pathname, $callback->($status)
727		845
728	Asynchronously rmdir (delete) a directory and call the callback with the	846	Asynchronously rmdir (delete) a directory and call the callback with the
729	result code.	847	result code.
		848
		849	On systems that support the AIO::WD working directory abstraction
		850	natively, the case C<[$wd, "."]> is specialcased - instead of failing,
		851	C<rmdir> is called on the absolute path of C<$wd>.
730		852
731		853
732	=item aio_readdir $pathname, $callback->($entries)	854	=item aio_readdir $pathname, $callback->($entries)
733		855
734	Unlike the POSIX call of the same name, C<aio_readdir> reads an entire	856	Unlike the POSIX call of the same name, C<aio_readdir> reads an entire
…		…
836	=item aio_copy $srcpath, $dstpath, $callback->($status)	958	=item aio_copy $srcpath, $dstpath, $callback->($status)
837		959
838	Try to copy the I<file> (directories not supported as either source or	960	Try to copy the I<file> (directories not supported as either source or
839	destination) from C<$srcpath> to C<$dstpath> and call the callback with	961	destination) from C<$srcpath> to C<$dstpath> and call the callback with
840	a status of C<0> (ok) or C<-1> (error, see C<$!>).	962	a status of C<0> (ok) or C<-1> (error, see C<$!>).
		963
		964	Existing destination files will be truncated.
841		965
842	This is a composite request that creates the destination file with	966	This is a composite request that creates the destination file with
843	mode 0200 and copies the contents of the source file into it using	967	mode 0200 and copies the contents of the source file into it using
844	C<aio_sendfile>, followed by restoring atime, mtime, access mode and	968	C<aio_sendfile>, followed by restoring atime, mtime, access mode and
845	uid/gid, in that order.	969	uid/gid, in that order.
…		…
955	Scans a directory (similar to C<aio_readdir>) but additionally tries to	1079	Scans a directory (similar to C<aio_readdir>) but additionally tries to
956	efficiently separate the entries of directory C<$path> into two sets of	1080	efficiently separate the entries of directory C<$path> into two sets of
957	names, directories you can recurse into (directories), and ones you cannot	1081	names, directories you can recurse into (directories), and ones you cannot
958	recurse into (everything else, including symlinks to directories).	1082	recurse into (everything else, including symlinks to directories).
959		1083
960	C<aio_scandir> is a composite request that creates of many sub requests_	1084	C<aio_scandir> is a composite request that generates many sub requests.
961	C<$maxreq> specifies the maximum number of outstanding aio requests that	1085	C<$maxreq> specifies the maximum number of outstanding aio requests that
962	this function generates. If it is C<< <= 0 >>, then a suitable default	1086	this function generates. If it is C<< <= 0 >>, then a suitable default
963	will be chosen (currently 4).	1087	will be chosen (currently 4).
964		1088
965	On error, the callback is called without arguments, otherwise it receives	1089	On error, the callback is called without arguments, otherwise it receives
…		…
1099	}	1223	}
1100		1224
1101	=item aio_rmtree $pathname, $callback->($status)	1225	=item aio_rmtree $pathname, $callback->($status)
1102		1226
1103	Delete a directory tree starting (and including) C<$path>, return the	1227	Delete a directory tree starting (and including) C<$path>, return the
1104	status of the final C<rmdir> only. This is a composite request that	1228	status of the final C<rmdir> only. This is a composite request that
1105	uses C<aio_scandir> to recurse into and rmdir directories, and unlink	1229	uses C<aio_scandir> to recurse into and rmdir directories, and unlink
1106	everything else.	1230	everything else.
1107		1231
1108	=cut	1232	=cut
1109		1233
…		…
1130	add $grp $dirgrp;	1254	add $grp $dirgrp;
1131	};	1255	};
1132		1256
1133	$grp	1257	$grp
1134	}	1258	}
		1259
		1260	=item aio_fcntl $fh, $cmd, $arg, $callback->($status)
		1261
		1262	=item aio_ioctl $fh, $request, $buf, $callback->($status)
		1263
		1264	These work just like the C<fcntl> and C<ioctl> built-in functions, except
		1265	they execute asynchronously and pass the return value to the callback.
		1266
		1267	Both calls can be used for a lot of things, some of which make more sense
		1268	to run asynchronously in their own thread, while some others make less
		1269	sense. For example, calls that block waiting for external events, such
		1270	as locking, will also lock down an I/O thread while it is waiting, which
		1271	can deadlock the whole I/O system. At the same time, there might be no
		1272	alternative to using a thread to wait.
		1273
		1274	So in general, you should only use these calls for things that do
		1275	(filesystem) I/O, not for things that wait for other events (network,
		1276	other processes), although if you are careful and know what you are doing,
		1277	you still can.
		1278
		1279	The following constants are available (missing ones are, as usual C<0>):
		1280
		1281	C<F_DUPFD_CLOEXEC>,
		1282
		1283	C<F_OFD_GETLK>, C<F_OFD_SETLK>, C<F_OFD_GETLKW>,
		1284
		1285	C<FIFREEZE>, C<FITHAW>, C<FITRIM>, C<FICLONE>, C<FICLONERANGE>, C<FIDEDUPERANGE>.
		1286
		1287	C<FS_IOC_GETFLAGS>, C<FS_IOC_SETFLAGS>, C<FS_IOC_GETVERSION>, C<FS_IOC_SETVERSION>,
		1288	C<FS_IOC_FIEMAP>.
		1289
		1290	C<FS_IOC_FSGETXATTR>, C<FS_IOC_FSSETXATTR>, C<FS_IOC_SET_ENCRYPTION_POLICY>,
		1291	C<FS_IOC_GET_ENCRYPTION_PWSALT>, C<FS_IOC_GET_ENCRYPTION_POLICY>, C<FS_KEY_DESCRIPTOR_SIZE>.
		1292
		1293	C<FS_SECRM_FL>, C<FS_UNRM_FL>, C<FS_COMPR_FL>, C<FS_SYNC_FL>, C<FS_IMMUTABLE_FL>,
		1294	C<FS_APPEND_FL>, C<FS_NODUMP_FL>, C<FS_NOATIME_FL>, C<FS_DIRTY_FL>,
		1295	C<FS_COMPRBLK_FL>, C<FS_NOCOMP_FL>, C<FS_ENCRYPT_FL>, C<FS_BTREE_FL>,
		1296	C<FS_INDEX_FL>, C<FS_JOURNAL_DATA_FL>, C<FS_NOTAIL_FL>, C<FS_DIRSYNC_FL>, C<FS_TOPDIR_FL>,
		1297	C<FS_FL_USER_MODIFIABLE>.
		1298
		1299	C<FS_XFLAG_REALTIME>, C<FS_XFLAG_PREALLOC>, C<FS_XFLAG_IMMUTABLE>, C<FS_XFLAG_APPEND>,
		1300	C<FS_XFLAG_SYNC>, C<FS_XFLAG_NOATIME>, C<FS_XFLAG_NODUMP>, C<FS_XFLAG_RTINHERIT>,
		1301	C<FS_XFLAG_PROJINHERIT>, C<FS_XFLAG_NOSYMLINKS>, C<FS_XFLAG_EXTSIZE>, C<FS_XFLAG_EXTSZINHERIT>,
		1302	C<FS_XFLAG_NODEFRAG>, C<FS_XFLAG_FILESTREAM>, C<FS_XFLAG_DAX>, C<FS_XFLAG_HASATTR>,
1135		1303
1136	=item aio_sync $callback->($status)	1304	=item aio_sync $callback->($status)
1137		1305
1138	Asynchronously call sync and call the callback when finished.	1306	Asynchronously call sync and call the callback when finished.
1139		1307
…		…
1208	};	1376	};
1209		1377
1210	$grp	1378	$grp
1211	}	1379	}
1212		1380
1213	=item aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)	1381	=item aio_msync $scalar, $offset = 0, $length = undef, flags = MS_SYNC, $callback->($status)
1214		1382
1215	This is a rather advanced IO::AIO call, which only works on mmap(2)ed	1383	This is a rather advanced IO::AIO call, which only works on mmap(2)ed
1216	scalars (see the C<IO::AIO::mmap> function, although it also works on data	1384	scalars (see the C<IO::AIO::mmap> function, although it also works on data
1217	scalars managed by the L<Sys::Mmap> or L<Mmap> modules, note that the	1385	scalars managed by the L<Sys::Mmap> or L<Mmap> modules, note that the
1218	scalar must only be modified in-place while an aio operation is pending on	1386	scalar must only be modified in-place while an aio operation is pending on
…		…
1220		1388
1221	It calls the C<msync> function of your OS, if available, with the memory	1389	It calls the C<msync> function of your OS, if available, with the memory
1222	area starting at C<$offset> in the string and ending C<$length> bytes	1390	area starting at C<$offset> in the string and ending C<$length> bytes
1223	later. If C<$length> is negative, counts from the end, and if C<$length>	1391	later. If C<$length> is negative, counts from the end, and if C<$length>
1224	is C<undef>, then it goes till the end of the string. The flags can be	1392	is C<undef>, then it goes till the end of the string. The flags can be
1225	a combination of C<IO::AIO::MS_ASYNC>, C<IO::AIO::MS_INVALIDATE> and	1393	either C<IO::AIO::MS_ASYNC> or C<IO::AIO::MS_SYNC>, plus an optional
1226	C<IO::AIO::MS_SYNC>.	1394	C<IO::AIO::MS_INVALIDATE>.
1227		1395
1228	=item aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)	1396	=item aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
1229		1397
1230	This is a rather advanced IO::AIO call, which works best on mmap(2)ed	1398	This is a rather advanced IO::AIO call, which works best on mmap(2)ed
1231	scalars.	1399	scalars.
1232		1400
1233	It touches (reads or writes) all memory pages in the specified	1401	It touches (reads or writes) all memory pages in the specified
1234	range inside the scalar. All caveats and parameters are the same	1402	range inside the scalar. All caveats and parameters are the same
1235	as for C<aio_msync>, above, except for flags, which must be either	1403	as for C<aio_msync>, above, except for flags, which must be either
1236	C<0> (which reads all pages and ensures they are instantiated) or	1404	C<0> (which reads all pages and ensures they are instantiated) or
1237	C<IO::AIO::MT_MODIFY>, which modifies the memory page s(by reading and	1405	C<IO::AIO::MT_MODIFY>, which modifies the memory pages (by reading and
1238	writing an octet from it, which dirties the page).	1406	writing an octet from it, which dirties the page).
1239		1407
1240	=item aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status)	1408	=item aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status)
1241		1409
1242	This is a rather advanced IO::AIO call, which works best on mmap(2)ed	1410	This is a rather advanced IO::AIO call, which works best on mmap(2)ed
…		…
1276		1444
1277	aio_mlockall IO::AIO::MCL_FUTURE;	1445	aio_mlockall IO::AIO::MCL_FUTURE;
1278		1446
1279	=item aio_fiemap $fh, $start, $length, $flags, $count, $cb->(\@extents)	1447	=item aio_fiemap $fh, $start, $length, $flags, $count, $cb->(\@extents)
1280		1448
1281	Queries the extents of the given file (by calling the Linux FIEMAP ioctl,	1449	Queries the extents of the given file (by calling the Linux C<FIEMAP>
1282	see L<http://cvs.schmorp.de/IO-AIO/doc/fiemap.txt> for details). If the	1450	ioctl, see L<http://cvs.schmorp.de/IO-AIO/doc/fiemap.txt> for details). If
1283	C<ioctl> is not available on your OS, then this rquiest will fail with	1451	the ioctl is not available on your OS, then this request will fail with
1284	C<ENOSYS>.	1452	C<ENOSYS>.
1285		1453
1286	C<$start> is the starting offset to query extents for, C<$length> is the	1454	C<$start> is the starting offset to query extents for, C<$length> is the
1287	size of the range to query - if it is C<undef>, then the whole file will	1455	size of the range to query - if it is C<undef>, then the whole file will
1288	be queried.	1456	be queried.
…		…
1291	C<IO::AIO::FIEMAP_FLAG_XATTR> - C<IO::AIO::FIEMAP_FLAGS_COMPAT> is also	1459	C<IO::AIO::FIEMAP_FLAG_XATTR> - C<IO::AIO::FIEMAP_FLAGS_COMPAT> is also
1292	exported), and is normally C<0> or C<IO::AIO::FIEMAP_FLAG_SYNC> to query	1460	exported), and is normally C<0> or C<IO::AIO::FIEMAP_FLAG_SYNC> to query
1293	the data portion.	1461	the data portion.
1294		1462
1295	C<$count> is the maximum number of extent records to return. If it is	1463	C<$count> is the maximum number of extent records to return. If it is
1296	C<undef>, then IO::AIO queries all extents of the file. As a very special	1464	C<undef>, then IO::AIO queries all extents of the range. As a very special
1297	case, if it is C<0>, then the callback receives the number of extents	1465	case, if it is C<0>, then the callback receives the number of extents
1298	instead of the extents themselves.	1466	instead of the extents themselves (which is unreliable, see below).
1299		1467
1300	If an error occurs, the callback receives no arguments. The special	1468	If an error occurs, the callback receives no arguments. The special
1301	C<errno> value C<IO::AIO::EBADR> is available to test for flag errors.	1469	C<errno> value C<IO::AIO::EBADR> is available to test for flag errors.
1302		1470
1303	Otherwise, the callback receives an array reference with extent	1471	Otherwise, the callback receives an array reference with extent
…		…
1305	following members:	1473	following members:
1306		1474
1307	[$logical, $physical, $length, $flags]	1475	[$logical, $physical, $length, $flags]
1308		1476
1309	Flags is any combination of the following flag values (typically either C<0>	1477	Flags is any combination of the following flag values (typically either C<0>
1310	or C<IO::AIO::FIEMAP_EXTENT_LAST>):	1478	or C<IO::AIO::FIEMAP_EXTENT_LAST> (1)):
1311		1479
1312	C<IO::AIO::FIEMAP_EXTENT_LAST>, C<IO::AIO::FIEMAP_EXTENT_UNKNOWN>,	1480	C<IO::AIO::FIEMAP_EXTENT_LAST>, C<IO::AIO::FIEMAP_EXTENT_UNKNOWN>,
1313	C<IO::AIO::FIEMAP_EXTENT_DELALLOC>, C<IO::AIO::FIEMAP_EXTENT_ENCODED>,	1481	C<IO::AIO::FIEMAP_EXTENT_DELALLOC>, C<IO::AIO::FIEMAP_EXTENT_ENCODED>,
1314	C<IO::AIO::FIEMAP_EXTENT_DATA_ENCRYPTED>, C<IO::AIO::FIEMAP_EXTENT_NOT_ALIGNED>,	1482	C<IO::AIO::FIEMAP_EXTENT_DATA_ENCRYPTED>, C<IO::AIO::FIEMAP_EXTENT_NOT_ALIGNED>,
1315	C<IO::AIO::FIEMAP_EXTENT_DATA_INLINE>, C<IO::AIO::FIEMAP_EXTENT_DATA_TAIL>,	1483	C<IO::AIO::FIEMAP_EXTENT_DATA_INLINE>, C<IO::AIO::FIEMAP_EXTENT_DATA_TAIL>,
1316	C<IO::AIO::FIEMAP_EXTENT_UNWRITTEN>, C<IO::AIO::FIEMAP_EXTENT_MERGED> or	1484	C<IO::AIO::FIEMAP_EXTENT_UNWRITTEN>, C<IO::AIO::FIEMAP_EXTENT_MERGED> or
1317	C<IO::AIO::FIEMAP_EXTENT_SHARED>.	1485	C<IO::AIO::FIEMAP_EXTENT_SHARED>.
1318		1486
		1487	At the time of this writing (Linux 3.2), this requets is unreliable unless
		1488	C<$count> is C<undef>, as the kernel has all sorts of bugs preventing
		1489	it to return all extents of a range for files with large number of
		1490	extents. The code works around all these issues if C<$count> is undef.
		1491
1319	=item aio_group $callback->(...)	1492	=item aio_group $callback->(...)
1320		1493
1321	This is a very special aio request: Instead of doing something, it is a	1494	This is a very special aio request: Instead of doing something, it is a
1322	container for other aio requests, which is useful if you want to bundle	1495	container for other aio requests, which is useful if you want to bundle
1323	many requests into a single, composite, request with a definite callback	1496	many requests into a single, composite, request with a definite callback
…		…
1406	aio_stat [$etcdir, "passwd"], sub {	1579	aio_stat [$etcdir, "passwd"], sub {
1407	# yay	1580	# yay
1408	};	1581	};
1409	};	1582	};
1410		1583
1411	That C<aio_wd> is a request and not a normal function shows that creating	1584	The fact that C<aio_wd> is a request and not a normal function shows that
1412	an IO::AIO::WD object is itself a potentially blocking operation, which is	1585	creating an IO::AIO::WD object is itself a potentially blocking operation,
1413	why it is done asynchronously.	1586	which is why it is done asynchronously.
1414		1587
1415	To stat the directory obtained with C<aio_wd> above, one could write	1588	To stat the directory obtained with C<aio_wd> above, one could write
1416	either of the following three request calls:	1589	either of the following three request calls:
1417		1590
1418	aio_lstat "/etc" , sub { ... # pathname as normal string	1591	aio_lstat "/etc" , sub { ... # pathname as normal string
…		…
1435	There are some caveats: when directories get renamed (or deleted), the	1608	There are some caveats: when directories get renamed (or deleted), the
1436	pathname string doesn't change, so will point to the new directory (or	1609	pathname string doesn't change, so will point to the new directory (or
1437	nowhere at all), while the directory fd, if available on the system,	1610	nowhere at all), while the directory fd, if available on the system,
1438	will still point to the original directory. Most functions accepting a	1611	will still point to the original directory. Most functions accepting a
1439	pathname will use the directory fd on newer systems, and the string on	1612	pathname will use the directory fd on newer systems, and the string on
1440	older systems. Some functions (such as realpath) will always rely on the	1613	older systems. Some functions (such as C<aio_realpath>) will always rely on
1441	string form of the pathname.	1614	the string form of the pathname.
1442		1615
1443	So this fucntionality is mainly useful to get some protection against	1616	So this functionality is mainly useful to get some protection against
1444	C<chdir>, to easily get an absolute path out of a relative path for future	1617	C<chdir>, to easily get an absolute path out of a relative path for future
1445	reference, and to speed up doing many operations in the same directory	1618	reference, and to speed up doing many operations in the same directory
1446	(e.g. when stat'ing all files in a directory).	1619	(e.g. when stat'ing all files in a directory).
1447		1620
1448	The following functions implement this working directory abstraction:	1621	The following functions implement this working directory abstraction:
…		…
1461	passing C<undef> as working directory component of a pathname fails the	1634	passing C<undef> as working directory component of a pathname fails the
1462	request with C<ENOENT>, there is often no need for error checking in the	1635	request with C<ENOENT>, there is often no need for error checking in the
1463	C<aio_wd> callback, as future requests using the value will fail in the	1636	C<aio_wd> callback, as future requests using the value will fail in the
1464	expected way.	1637	expected way.
1465		1638
1466	If this call isn't available because your OS lacks it or it couldn't be
1467	detected, it will be emulated by calling C<fsync> instead.
1468
1469	=item IO::AIO::CWD	1639	=item IO::AIO::CWD
1470		1640
1471	This is a compiletime constant (object) that represents the process	1641	This is a compiletime constant (object) that represents the process
1472	current working directory.	1642	current working directory.
1473		1643
1474	Specifying this object as working directory object for a pathname is as	1644	Specifying this object as working directory object for a pathname is as if
1475	if the pathname would be specified directly, without a directory object,	1645	the pathname would be specified directly, without a directory object. For
1476	e.g., these calls are functionally identical:	1646	example, these calls are functionally identical:
1477		1647
1478	aio_stat "somefile", sub { ... };	1648	aio_stat "somefile", sub { ... };
1479	aio_stat [IO::AIO::CWD, "somefile"], sub { ... };	1649	aio_stat [IO::AIO::CWD, "somefile"], sub { ... };
1480		1650
1481	=back	1651	=back
1482		1652
		1653	To recover the path associated with an IO::AIO::WD object, you can use
		1654	C<aio_realpath>:
		1655
		1656	aio_realpath $wd, sub {
		1657	warn "path is $_[0]\n";
		1658	};
		1659
		1660	Currently, C<aio_statvfs> always, and C<aio_rename> and C<aio_rmdir>
		1661	sometimes, fall back to using an absolue path.
1483		1662
1484	=head2 IO::AIO::REQ CLASS	1663	=head2 IO::AIO::REQ CLASS
1485		1664
1486	All non-aggregate C<aio_*> functions return an object of this class when	1665	All non-aggregate C<aio_*> functions return an object of this class when
1487	called in non-void context.	1666	called in non-void context.
…		…
1665		1844
1666	See C<poll_cb> for an example.	1845	See C<poll_cb> for an example.
1667		1846
1668	=item IO::AIO::poll_cb	1847	=item IO::AIO::poll_cb
1669		1848
1670	Process some outstanding events on the result pipe. You have to call	1849	Process some requests that have reached the result phase (i.e. they have
		1850	been executed but the results are not yet reported). You have to call
		1851	this "regularly" to finish outstanding requests.
		1852
1671	this regularly. Returns C<0> if all events could be processed (or there	1853	Returns C<0> if all events could be processed (or there were no
1672	were no events to process), or C<-1> if it returned earlier for whatever	1854	events to process), or C<-1> if it returned earlier for whatever
1673	reason. Returns immediately when no events are outstanding. The amount of	1855	reason. Returns immediately when no events are outstanding. The amount
1674	events processed depends on the settings of C<IO::AIO::max_poll_req> and	1856	of events processed depends on the settings of C<IO::AIO::max_poll_req>,
1675	C<IO::AIO::max_poll_time>.	1857	C<IO::AIO::max_poll_time> and C<IO::AIO::max_outstanding>.
1676		1858
1677	If not all requests were processed for whatever reason, the filehandle	1859	If not all requests were processed for whatever reason, the poll file
1678	will still be ready when C<poll_cb> returns, so normally you don't have to	1860	descriptor will still be ready when C<poll_cb> returns, so normally you
1679	do anything special to have it called later.	1861	don't have to do anything special to have it called later.
1680		1862
1681	Apart from calling C<IO::AIO::poll_cb> when the event filehandle becomes	1863	Apart from calling C<IO::AIO::poll_cb> when the event filehandle becomes
1682	ready, it can be beneficial to call this function from loops which submit	1864	ready, it can be beneficial to call this function from loops which submit
1683	a lot of requests, to make sure the results get processed when they become	1865	a lot of requests, to make sure the results get processed when they become
1684	available and not just when the loop is finished and the event loop takes	1866	available and not just when the loop is finished and the event loop takes
…		…
1693	poll => 'r', async => 1,	1875	poll => 'r', async => 1,
1694	cb => \&IO::AIO::poll_cb);	1876	cb => \&IO::AIO::poll_cb);
1695		1877
1696	=item IO::AIO::poll_wait	1878	=item IO::AIO::poll_wait
1697		1879
1698	If there are any outstanding requests and none of them in the result	1880	Wait until either at least one request is in the result phase or no
1699	phase, wait till the result filehandle becomes ready for reading (simply	1881	requests are outstanding anymore.
1700	does a C<select> on the filehandle. This is useful if you want to	1882
1701	synchronously wait for some requests to finish).	1883	This is useful if you want to synchronously wait for some requests to
		1884	become ready, without actually handling them.
1702		1885
1703	See C<nreqs> for an example.	1886	See C<nreqs> for an example.
1704		1887
1705	=item IO::AIO::poll	1888	=item IO::AIO::poll
1706		1889
…		…
1827		2010
1828	This is a very bad function to use in interactive programs because it	2011	This is a very bad function to use in interactive programs because it
1829	blocks, and a bad way to reduce concurrency because it is inexact: Better	2012	blocks, and a bad way to reduce concurrency because it is inexact: Better
1830	use an C<aio_group> together with a feed callback.	2013	use an C<aio_group> together with a feed callback.
1831		2014
1832	It's main use is in scripts without an event loop - when you want to stat	2015	Its main use is in scripts without an event loop - when you want to stat
1833	a lot of files, you can write somehting like this:	2016	a lot of files, you can write something like this:
1834		2017
1835	IO::AIO::max_outstanding 32;	2018	IO::AIO::max_outstanding 32;
1836		2019
1837	for my $path (...) {	2020	for my $path (...) {
1838	aio_stat $path , ...;	2021	aio_stat $path , ...;
…		…
1877		2060
1878	=back	2061	=back
1879		2062
1880	=head3 MISCELLANEOUS FUNCTIONS	2063	=head3 MISCELLANEOUS FUNCTIONS
1881		2064
1882	IO::AIO implements some functions that might be useful, but are not	2065	IO::AIO implements some functions that are useful when you want to use
1883	asynchronous.	2066	some "Advanced I/O" function not available to in Perl, without going the
		2067	"Asynchronous I/O" route. Many of these have an asynchronous C<aio_*>
		2068	counterpart.
1884		2069
1885	=over 4	2070	=over 4
		2071
		2072	=item $numfd = IO::AIO::get_fdlimit
		2073
		2074	Tries to find the current file descriptor limit and returns it, or
		2075	C<undef> and sets C<$!> in case of an error. The limit is one larger than
		2076	the highest valid file descriptor number.
		2077
		2078	=item IO::AIO::min_fdlimit [$numfd]
		2079
		2080	Try to increase the current file descriptor limit(s) to at least C<$numfd>
		2081	by changing the soft or hard file descriptor resource limit. If C<$numfd>
		2082	is missing, it will try to set a very high limit, although this is not
		2083	recommended when you know the actual minimum that you require.
		2084
		2085	If the limit cannot be raised enough, the function makes a best-effort
		2086	attempt to increase the limit as much as possible, using various
		2087	tricks, while still failing. You can query the resulting limit using
		2088	C<IO::AIO::get_fdlimit>.
		2089
		2090	If an error occurs, returns C<undef> and sets C<$!>, otherwise returns
		2091	true.
1886		2092
1887	=item IO::AIO::sendfile $ofh, $ifh, $offset, $count	2093	=item IO::AIO::sendfile $ofh, $ifh, $offset, $count
1888		2094
1889	Calls the C<eio_sendfile_sync> function, which is like C<aio_sendfile>,	2095	Calls the C<eio_sendfile_sync> function, which is like C<aio_sendfile>,
1890	but is blocking (this makes most sense if you know the input data is	2096	but is blocking (this makes most sense if you know the input data is
…		…
1907	=item IO::AIO::madvise $scalar, $offset, $len, $advice	2113	=item IO::AIO::madvise $scalar, $offset, $len, $advice
1908		2114
1909	Simply calls the C<posix_madvise> function (see its	2115	Simply calls the C<posix_madvise> function (see its
1910	manpage for details). The following advice constants are	2116	manpage for details). The following advice constants are
1911	available: C<IO::AIO::MADV_NORMAL>, C<IO::AIO::MADV_SEQUENTIAL>,	2117	available: C<IO::AIO::MADV_NORMAL>, C<IO::AIO::MADV_SEQUENTIAL>,
1912	C<IO::AIO::MADV_RANDOM>, C<IO::AIO::MADV_WILLNEED>, C<IO::AIO::MADV_DONTNEED>.	2118	C<IO::AIO::MADV_RANDOM>, C<IO::AIO::MADV_WILLNEED>,
		2119	C<IO::AIO::MADV_DONTNEED>.
		2120
		2121	If C<$offset> is negative, counts from the end. If C<$length> is negative,
		2122	the remaining length of the C<$scalar> is used. If possible, C<$length>
		2123	will be reduced to fit into the C<$scalar>.
1913		2124
1914	On systems that do not implement C<posix_madvise>, this function returns	2125	On systems that do not implement C<posix_madvise>, this function returns
1915	ENOSYS, otherwise the return value of C<posix_madvise>.	2126	ENOSYS, otherwise the return value of C<posix_madvise>.
1916		2127
1917	=item IO::AIO::mprotect $scalar, $offset, $len, $protect	2128	=item IO::AIO::mprotect $scalar, $offset, $len, $protect
…		…
1919	Simply calls the C<mprotect> function on the preferably AIO::mmap'ed	2130	Simply calls the C<mprotect> function on the preferably AIO::mmap'ed
1920	$scalar (see its manpage for details). The following protect	2131	$scalar (see its manpage for details). The following protect
1921	constants are available: C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_READ>,	2132	constants are available: C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_READ>,
1922	C<IO::AIO::PROT_WRITE>, C<IO::AIO::PROT_EXEC>.	2133	C<IO::AIO::PROT_WRITE>, C<IO::AIO::PROT_EXEC>.
1923		2134
		2135	If C<$offset> is negative, counts from the end. If C<$length> is negative,
		2136	the remaining length of the C<$scalar> is used. If possible, C<$length>
		2137	will be reduced to fit into the C<$scalar>.
		2138
1924	On systems that do not implement C<mprotect>, this function returns	2139	On systems that do not implement C<mprotect>, this function returns
1925	ENOSYS, otherwise the return value of C<mprotect>.	2140	ENOSYS, otherwise the return value of C<mprotect>.
1926		2141
1927	=item IO::AIO::mmap $scalar, $length, $prot, $flags, $fh[, $offset]	2142	=item IO::AIO::mmap $scalar, $length, $prot, $flags, $fh[, $offset]
1928		2143
1929	Memory-maps a file (or anonymous memory range) and attaches it to the	2144	Memory-maps a file (or anonymous memory range) and attaches it to the
1930	given C<$scalar>, which will act like a string scalar. Returns true on	2145	given C<$scalar>, which will act like a string scalar. Returns true on
1931	success, and false otherwise.	2146	success, and false otherwise.
1932		2147
		2148	The scalar must exist, but its contents do not matter - this means you
		2149	cannot use a nonexistant array or hash element. When in doubt, C<undef>
		2150	the scalar first.
		2151
1933	The only operations allowed on the scalar are C<substr>/C<vec> that don't	2152	The only operations allowed on the mmapped scalar are C<substr>/C<vec>,
1934	change the string length, and most read-only operations such as copying it	2153	which don't change the string length, and most read-only operations such
1935	or searching it with regexes and so on.	2154	as copying it or searching it with regexes and so on.
1936		2155
1937	Anything else is unsafe and will, at best, result in memory leaks.	2156	Anything else is unsafe and will, at best, result in memory leaks.
1938		2157
1939	The memory map associated with the C<$scalar> is automatically removed	2158	The memory map associated with the C<$scalar> is automatically removed
1940	when the C<$scalar> is destroyed, or when the C<IO::AIO::mmap> or	2159	when the C<$scalar> is undef'd or destroyed, or when the C<IO::AIO::mmap>
1941	C<IO::AIO::munmap> functions are called.	2160	or C<IO::AIO::munmap> functions are called on it.
1942		2161
1943	This calls the C<mmap>(2) function internally. See your system's manual	2162	This calls the C<mmap>(2) function internally. See your system's manual
1944	page for details on the C<$length>, C<$prot> and C<$flags> parameters.	2163	page for details on the C<$length>, C<$prot> and C<$flags> parameters.
1945		2164
1946	The C<$length> must be larger than zero and smaller than the actual	2165	The C<$length> must be larger than zero and smaller than the actual
1947	filesize.	2166	filesize.
1948		2167
1949	C<$prot> is a combination of C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_EXEC>,	2168	C<$prot> is a combination of C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_EXEC>,
1950	C<IO::AIO::PROT_READ> and/or C<IO::AIO::PROT_WRITE>,	2169	C<IO::AIO::PROT_READ> and/or C<IO::AIO::PROT_WRITE>,
1951		2170
1952	C<$flags> can be a combination of C<IO::AIO::MAP_SHARED> or	2171	C<$flags> can be a combination of
1953	C<IO::AIO::MAP_PRIVATE>, or a number of system-specific flags (when	2172	C<IO::AIO::MAP_SHARED> or
1954	not available, the are defined as 0): C<IO::AIO::MAP_ANONYMOUS>	2173	C<IO::AIO::MAP_PRIVATE>,
		2174	or a number of system-specific flags (when not available, the are C<0>):
1955	(which is set to C<MAP_ANON> if your system only provides this	2175	C<IO::AIO::MAP_ANONYMOUS> (which is set to C<MAP_ANON> if your system only provides this constant),
1956	constant), C<IO::AIO::MAP_HUGETLB>, C<IO::AIO::MAP_LOCKED>,	2176	C<IO::AIO::MAP_LOCKED>,
1957	C<IO::AIO::MAP_NORESERVE>, C<IO::AIO::MAP_POPULATE> or	2177	C<IO::AIO::MAP_NORESERVE>,
		2178	C<IO::AIO::MAP_POPULATE>,
1958	C<IO::AIO::MAP_NONBLOCK>	2179	C<IO::AIO::MAP_NONBLOCK>,
		2180	C<IO::AIO::MAP_FIXED>,
		2181	C<IO::AIO::MAP_GROWSDOWN>,
		2182	C<IO::AIO::MAP_32BIT>,
		2183	C<IO::AIO::MAP_HUGETLB> or
		2184	C<IO::AIO::MAP_STACK>.
1959		2185
1960	If C<$fh> is C<undef>, then a file descriptor of C<-1> is passed.	2186	If C<$fh> is C<undef>, then a file descriptor of C<-1> is passed.
1961		2187
1962	C<$offset> is the offset from the start of the file - it generally must be	2188	C<$offset> is the offset from the start of the file - it generally must be
1963	a multiple of C<IO::AIO::PAGESIZE> and defaults to C<0>.	2189	a multiple of C<IO::AIO::PAGESIZE> and defaults to C<0>.
…		…
2006		2232
2007	See the C<splice(2)> manpage for details.	2233	See the C<splice(2)> manpage for details.
2008		2234
2009	=item IO::AIO::tee $r_fh, $w_fh, $length, $flags	2235	=item IO::AIO::tee $r_fh, $w_fh, $length, $flags
2010		2236
2011	Calls the GNU/Linux C<tee(2)> syscall, see it's manpage and the	2237	Calls the GNU/Linux C<tee(2)> syscall, see its manpage and the
2012	description for C<IO::AIO::splice> above for details.	2238	description for C<IO::AIO::splice> above for details.
		2239
		2240	=item $actual_size = IO::AIO::pipesize $r_fh[, $new_size]
		2241
		2242	Attempts to query or change the pipe buffer size. Obviously works only
		2243	on pipes, and currently works only on GNU/Linux systems, and fails with
		2244	C<-1>/C<ENOSYS> everywhere else. If anybody knows how to influence pipe buffer
		2245	size on other systems, drop me a note.
		2246
		2247	=item ($rfh, $wfh) = IO::AIO::pipe2 [$flags]
		2248
		2249	This is a direct interface to the Linux L<pipe2(2)> system call. If
		2250	C<$flags> is missing or C<0>, then this should be the same as a call to
		2251	perl's built-in C<pipe> function and create a new pipe, and works on
		2252	systems that lack the pipe2 syscall. On win32, this case invokes C<_pipe
		2253	(..., 4096, O_BINARY)>.
		2254
		2255	If C<$flags> is non-zero, it tries to invoke the pipe2 system call with
		2256	the given flags (Linux 2.6.27, glibc 2.9).
		2257
		2258	On success, the read and write file handles are returned.
		2259
		2260	On error, nothing will be returned. If the pipe2 syscall is missing and
		2261	C<$flags> is non-zero, fails with C<ENOSYS>.
		2262
		2263	Please refer to L<pipe2(2)> for more info on the C<$flags>, but at the
		2264	time of this writing, C<IO::AIO::O_CLOEXEC>, C<IO::AIO::O_NONBLOCK> and
		2265	C<IO::AIO::O_DIRECT> (Linux 3.4, for packet-based pipes) were supported.
2013		2266
2014	=back	2267	=back
2015		2268
2016	=cut	2269	=cut
2017		2270

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Comparing IO-AIO/AIO.pm (file contents): Revision 1.229 by root, Wed Jul 25 16:32:30 2012 UTC vs. Revision 1.277 by root, Fri Sep 22 12:17:49 2017 UTC

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Comparing IO-AIO/AIO.pm (file contents):
Revision 1.229 by root, Wed Jul 25 16:32:30 2012 UTC vs.
Revision 1.277 by root, Fri Sep 22 12:17:49 2017 UTC