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

Comparing IO-AIO/AIO.pm (file contents):
Revision 1.218 by root, Fri Dec 30 07:52:12 2011 UTC vs.
Revision 1.270 by root, Fri Jun 23 03:23:19 2017 UTC

…		…
1	=head1 NAME	1	=head1 NAME
2		2
3	IO::AIO - Asynchronous Input/Output	3	IO::AIO - Asynchronous/Advanced Input/Output
4		4
5	=head1 SYNOPSIS	5	=head1 SYNOPSIS
6		6
7	use IO::AIO;	7	use IO::AIO;
8		8
58	not well-supported or restricted (GNU/Linux doesn't allow them on normal	58	not well-supported or restricted (GNU/Linux doesn't allow them on normal
59	files currently, for example), and they would only support aio_read and	59	files currently, for example), and they would only support aio_read and
60	aio_write, so the remaining functionality would have to be implemented	60	aio_write, so the remaining functionality would have to be implemented
61	using threads anyway.	61	using threads anyway.
62		62
		63	In addition to asynchronous I/O, this module also exports some rather
		64	arcane interfaces, such as C<madvise> or linux's C<splice> system call,
		65	which is why the C<A> in C<AIO> can also mean I<advanced>.
		66
63	Although the module will work in the presence of other (Perl-) threads,	67	Although the module will work in the presence of other (Perl-) threads,
64	it is currently not reentrant in any way, so use appropriate locking	68	it is currently not reentrant in any way, so use appropriate locking
65	yourself, always call C<poll_cb> from within the same thread, or never	69	yourself, always call C<poll_cb> from within the same thread, or never
66	call C<poll_cb> (or other C<aio_> functions) recursively.	70	call C<poll_cb> (or other C<aio_> functions) recursively.
67		71
68	=head2 EXAMPLE	72	=head2 EXAMPLE
69		73
70	This is a simple example that uses the EV module and loads	74	This is a simple example that uses the EV module and loads
71	F</etc/passwd> asynchronously:	75	F</etc/passwd> asynchronously:
72		76
73	use Fcntl;
74	use EV;	77	use EV;
75	use IO::AIO;	78	use IO::AIO;
76		79
77	# register the IO::AIO callback with EV	80	# register the IO::AIO callback with EV
78	my $aio_w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb;	81	my $aio_w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb;
…		…
95		98
96	# file contents now in $contents	99	# file contents now in $contents
97	print $contents;	100	print $contents;
98		101
99	# exit event loop and program	102	# exit event loop and program
100	EV::unloop;	103	EV::break;
101	};	104	};
102	};	105	};
103		106
104	# possibly queue up other requests, or open GUI windows,	107	# possibly queue up other requests, or open GUI windows,
105	# check for sockets etc. etc.	108	# check for sockets etc. etc.
106		109
107	# process events as long as there are some:	110	# process events as long as there are some:
108	EV::loop;	111	EV::run;
109		112
110	=head1 REQUEST ANATOMY AND LIFETIME	113	=head1 REQUEST ANATOMY AND LIFETIME
111		114
112	Every C<aio_*> function creates a request. which is a C data structure not	115	Every C<aio_*> function creates a request. which is a C data structure not
113	directly visible to Perl.	116	directly visible to Perl.
…		…
168	use common::sense;	171	use common::sense;
169		172
170	use base 'Exporter';	173	use base 'Exporter';
171		174
172	BEGIN {	175	BEGIN {
173	our $VERSION = '4.12';	176	our $VERSION = 4.35;
174		177
175	our @AIO_REQ = qw(aio_sendfile 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)
		217	aio_seek $fh,$offset,$whence, $callback->($offs)
214	aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)	218	aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
215	aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)	219	aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
216	aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval)	220	aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval)
217	aio_readahead $fh,$offset,$length, $callback->($retval)	221	aio_readahead $fh,$offset,$length, $callback->($retval)
218	aio_stat $fh_or_path, $callback->($status)	222	aio_stat $fh_or_path, $callback->($status)
219	aio_lstat $fh, $callback->($status)	223	aio_lstat $fh, $callback->($status)
220	aio_statvfs $fh_or_path, $callback->($statvfs)	224	aio_statvfs $fh_or_path, $callback->($statvfs)
221	aio_utime $fh_or_path, $atime, $mtime, $callback->($status)	225	aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
222	aio_chown $fh_or_path, $uid, $gid, $callback->($status)	226	aio_chown $fh_or_path, $uid, $gid, $callback->($status)
		227	aio_chmod $fh_or_path, $mode, $callback->($status)
223	aio_truncate $fh_or_path, $offset, $callback->($status)	228	aio_truncate $fh_or_path, $offset, $callback->($status)
224	aio_chmod $fh_or_path, $mode, $callback->($status)	229	aio_allocate $fh, $mode, $offset, $len, $callback->($status)
		230	aio_fiemap $fh, $start, $length, $flags, $count, $cb->(\@extents)
225	aio_unlink $pathname, $callback->($status)	231	aio_unlink $pathname, $callback->($status)
226	aio_mknod $pathname, $mode, $dev, $callback->($status)	232	aio_mknod $pathname, $mode, $dev, $callback->($status)
227	aio_link $srcpath, $dstpath, $callback->($status)	233	aio_link $srcpath, $dstpath, $callback->($status)
228	aio_symlink $srcpath, $dstpath, $callback->($status)	234	aio_symlink $srcpath, $dstpath, $callback->($status)
229	aio_readlink $pathname, $callback->($link)	235	aio_readlink $pathname, $callback->($link)
230	aio_realpath $pathname, $callback->($link)	236	aio_realpath $pathname, $callback->($path)
231	aio_rename $srcpath, $dstpath, $callback->($status)	237	aio_rename $srcpath, $dstpath, $callback->($status)
		238	aio_rename2 $srcpath, $dstpath, $flags, $callback->($status)
232	aio_mkdir $pathname, $mode, $callback->($status)	239	aio_mkdir $pathname, $mode, $callback->($status)
233	aio_rmdir $pathname, $callback->($status)	240	aio_rmdir $pathname, $callback->($status)
234	aio_readdir $pathname, $callback->($entries)	241	aio_readdir $pathname, $callback->($entries)
235	aio_readdirx $pathname, $flags, $callback->($entries, $flags)	242	aio_readdirx $pathname, $flags, $callback->($entries, $flags)
236	IO::AIO::READDIR_DENTS IO::AIO::READDIR_DIRS_FIRST	243	IO::AIO::READDIR_DENTS IO::AIO::READDIR_DIRS_FIRST
…		…
238	aio_scandir $pathname, $maxreq, $callback->($dirs, $nondirs)	245	aio_scandir $pathname, $maxreq, $callback->($dirs, $nondirs)
239	aio_load $pathname, $data, $callback->($status)	246	aio_load $pathname, $data, $callback->($status)
240	aio_copy $srcpath, $dstpath, $callback->($status)	247	aio_copy $srcpath, $dstpath, $callback->($status)
241	aio_move $srcpath, $dstpath, $callback->($status)	248	aio_move $srcpath, $dstpath, $callback->($status)
242	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)
243	aio_sync $callback->($status)	252	aio_sync $callback->($status)
244	aio_syncfs $fh, $callback->($status)	253	aio_syncfs $fh, $callback->($status)
245	aio_fsync $fh, $callback->($status)	254	aio_fsync $fh, $callback->($status)
246	aio_fdatasync $fh, $callback->($status)	255	aio_fdatasync $fh, $callback->($status)
247	aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status)	256	aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status)
248	aio_pathsync $pathname, $callback->($status)	257	aio_pathsync $pathname, $callback->($status)
249	aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)	258	aio_msync $scalar, $offset = 0, $length = undef, flags = MS_SYNC, $callback->($status)
250	aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)	259	aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
251	aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status)	260	aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status)
252	aio_mlockall $flags, $callback->($status)	261	aio_mlockall $flags, $callback->($status)
253	aio_group $callback->(...)	262	aio_group $callback->(...)
254	aio_nop $callback->()	263	aio_nop $callback->()
…		…
271	IO::AIO::nready	280	IO::AIO::nready
272	IO::AIO::npending	281	IO::AIO::npending
273		282
274	IO::AIO::sendfile $ofh, $ifh, $offset, $count	283	IO::AIO::sendfile $ofh, $ifh, $offset, $count
275	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
276	IO::AIO::madvise $scalar, $offset, $length, $advice	287	IO::AIO::madvise $scalar, $offset, $length, $advice
277	IO::AIO::mprotect $scalar, $offset, $length, $protect	288	IO::AIO::mprotect $scalar, $offset, $length, $protect
278	IO::AIO::munlock $scalar, $offset = 0, $length = undef	289	IO::AIO::munlock $scalar, $offset = 0, $length = undef
279	IO::AIO::munlockall	290	IO::AIO::munlockall
280		291
281	=head2 AIO REQUEST FUNCTIONS	292	=head2 API NOTES
282		293
283	All the C<aio_*> calls are more or less thin wrappers around the syscall	294	All the C<aio_*> calls are more or less thin wrappers around the syscall
284	with the same name (sans C<aio_>). The arguments are similar or identical,	295	with the same name (sans C<aio_>). The arguments are similar or identical,
285	and they all accept an additional (and optional) C<$callback> argument	296	and they all accept an additional (and optional) C<$callback> argument
286	which must be a code reference. This code reference will be called after	297	which must be a code reference. This code reference will be called after
…		…
317	correct contents.	328	correct contents.
318		329
319	This works, btw. independent of the internal UTF-8 bit, which IO::AIO	330	This works, btw. independent of the internal UTF-8 bit, which IO::AIO
320	handles correctly whether it is set or not.	331	handles correctly whether it is set or not.
321		332
		333	=head2 AIO REQUEST FUNCTIONS
		334
322	=over 4	335	=over 4
323		336
324	=item $prev_pri = aioreq_pri [$pri]	337	=item $prev_pri = aioreq_pri [$pri]
325		338
326	Returns the priority value that would be used for the next request and, if	339	Returns the priority value that would be used for the next request and, if
…		…
355		368
356		369
357	=item aio_open $pathname, $flags, $mode, $callback->($fh)	370	=item aio_open $pathname, $flags, $mode, $callback->($fh)
358		371
359	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
360	created filehandle for the file.	373	created filehandle for the file (or C<undef> in case of an error).
361		374
362	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,
363	for an explanation.	376	for an explanation.
364		377
365	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
…		…
388	following POSIX and non-POSIX constants are available (missing ones on	401	following POSIX and non-POSIX constants are available (missing ones on
389	your system are, as usual, C<0>):	402	your system are, as usual, C<0>):
390		403
391	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>,
392	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>,
393	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>.
394		407
395		408
396	=item aio_close $fh, $callback->($status)	409	=item aio_close $fh, $callback->($status)
397		410
398	Asynchronously close a file and call the callback with the result	411	Asynchronously close a file and call the callback with the result
…		…
408	Or in other words: the file descriptor will be closed, but it will not be	421	Or in other words: the file descriptor will be closed, but it will not be
409	free for reuse until the perl filehandle is closed.	422	free for reuse until the perl filehandle is closed.
410		423
411	=cut	424	=cut
412		425
		426	=item aio_seek $fh, $offset, $whence, $callback->($offs)
		427
		428	Seeks the filehandle to the new C<$offset>, similarly to perl's
		429	C<sysseek>. The C<$whence> can use the traditional values (C<0> for
		430	C<IO::AIO::SEEK_SET>, C<1> for C<IO::AIO::SEEK_CUR> or C<2> for
		431	C<IO::AIO::SEEK_END>).
		432
		433	The resulting absolute offset will be passed to the callback, or C<-1> in
		434	case of an error.
		435
		436	In theory, the C<$whence> constants could be different than the
		437	corresponding values from L<Fcntl>, but perl guarantees they are the same,
		438	so don't panic.
		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
413	=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)	446	=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
414		447
415	=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)	448	=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
416		449
417	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
418	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
419	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
420	error, just like the syscall).	453	error, just like the syscall).
421		454
422	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
423	offset plus the actual number of bytes read.	456	offset plus the actual number of bytes read.
424		457
…		…
482	As native sendfile syscalls (as practically any non-POSIX interface hacked	515	As native sendfile syscalls (as practically any non-POSIX interface hacked
483	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
484	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
485	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,
486	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> -
487	fewre bytes than expected might have been transferred.	520	fewer bytes than expected might have been transferred.
488		521
489		522
490	=item aio_readahead $fh,$offset,$length, $callback->($retval)	523	=item aio_readahead $fh,$offset,$length, $callback->($retval)
491		524
492	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
…		…
496	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
497	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
498	(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
499	file. The current file offset of the file is left unchanged.	532	file. The current file offset of the file is left unchanged.
500		533
501	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
502	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.
503		536
504		537
505	=item aio_stat $fh_or_path, $callback->($status)	538	=item aio_stat $fh_or_path, $callback->($status)
506		539
507	=item aio_lstat $fh, $callback->($status)	540	=item aio_lstat $fh, $callback->($status)
…		…
576	namemax => 255,	609	namemax => 255,
577	frsize => 1024,	610	frsize => 1024,
578	fsid => 1810	611	fsid => 1810
579	}	612	}
580		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
581		698
582	=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status)	699	=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
583		700
584	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
585	and $mtime being undef). Fractional times are supported if the underlying	702	and $mtime being undef). Fractional times are supported if the underlying
…		…
613	=item aio_truncate $fh_or_path, $offset, $callback->($status)	730	=item aio_truncate $fh_or_path, $offset, $callback->($status)
614		731
615	Works like truncate(2) or ftruncate(2).	732	Works like truncate(2) or ftruncate(2).
616		733
617		734
		735	=item aio_allocate $fh, $mode, $offset, $len, $callback->($status)
		736
		737	Allocates or frees disk space according to the C<$mode> argument. See the
		738	linux C<fallocate> documentation for details.
		739
		740	C<$mode> is usually C<0> or C<IO::AIO::FALLOC_FL_KEEP_SIZE> to allocate
		741	space, or C<IO::AIO::FALLOC_FL_PUNCH_HOLE \| IO::AIO::FALLOC_FL_KEEP_SIZE>,
		742	to deallocate a file range.
		743
		744	IO::AIO also supports C<FALLOC_FL_COLLAPSE_RANGE>, to remove a range
		745	(without leaving a hole) and C<FALLOC_FL_ZERO_RANGE>, to zero a range (see
		746	your L<fallocate(2)> manpage).
		747
		748	The file system block size used by C<fallocate> is presumably the
		749	C<f_bsize> returned by C<statvfs>.
		750
		751	If C<fallocate> isn't available or cannot be emulated (currently no
		752	emulation will be attempted), passes C<-1> and sets C<$!> to C<ENOSYS>.
		753
		754
618	=item aio_chmod $fh_or_path, $mode, $callback->($status)	755	=item aio_chmod $fh_or_path, $mode, $callback->($status)
619		756
620	Works like perl's C<chmod> function.	757	Works like perl's C<chmod> function.
621		758
622		759
…		…
659		796
660		797
661	=item aio_realpath $pathname, $callback->($path)	798	=item aio_realpath $pathname, $callback->($path)
662		799
663	Asynchronously make the path absolute and resolve any symlinks in	800	Asynchronously make the path absolute and resolve any symlinks in
664	C<$path>. The resulting path only consists of directories (Same as	801	C<$path>. The resulting path only consists of directories (same as
665	L<Cwd::realpath>).	802	L<Cwd::realpath>).
666		803
667	This request can be used to get the absolute path of the current working	804	This request can be used to get the absolute path of the current working
668	directory by passing it a path of F<.> (a single dot).	805	directory by passing it a path of F<.> (a single dot).
669		806
670		807
671	=item aio_rename $srcpath, $dstpath, $callback->($status)	808	=item aio_rename $srcpath, $dstpath, $callback->($status)
672		809
673	Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as	810	Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as
674	rename(2) and call the callback with the result code.	811	rename(2) and call the callback with the result code.
		812
		813	On systems that support the AIO::WD working directory abstraction
		814	natively, the case C<[$wd, "."]> as C<$srcpath> is specialcased - instead
		815	of failing, C<rename> is called on the absolute path of C<$wd>.
		816
		817
		818	=item aio_rename2 $srcpath, $dstpath, $flags, $callback->($status)
		819
		820	Basically a version of C<aio_rename> with an additional C<$flags>
		821	argument. Calling this with C<$flags=0> is the same as calling
		822	C<aio_rename>.
		823
		824	Non-zero flags are currently only supported on GNU/Linux systems that
		825	support renameat2. Other systems fail with C<ENOSYS> in this case.
		826
		827	The following constants are available (missing ones are, as usual C<0>),
		828	see renameat2(2) for details:
		829
		830	C<IO::AIO::RENAME_NOREPLACE>, C<IO::AIO::RENAME_EXCHANGE>
		831	and C<IO::AIO::RENAME_WHITEOUT>.
675		832
676		833
677	=item aio_mkdir $pathname, $mode, $callback->($status)	834	=item aio_mkdir $pathname, $mode, $callback->($status)
678		835
679	Asynchronously mkdir (create) a directory and call the callback with	836	Asynchronously mkdir (create) a directory and call the callback with
…		…
683		840
684	=item aio_rmdir $pathname, $callback->($status)	841	=item aio_rmdir $pathname, $callback->($status)
685		842
686	Asynchronously rmdir (delete) a directory and call the callback with the	843	Asynchronously rmdir (delete) a directory and call the callback with the
687	result code.	844	result code.
		845
		846	On systems that support the AIO::WD working directory abstraction
		847	natively, the case C<[$wd, "."]> is specialcased - instead of failing,
		848	C<rmdir> is called on the absolute path of C<$wd>.
688		849
689		850
690	=item aio_readdir $pathname, $callback->($entries)	851	=item aio_readdir $pathname, $callback->($entries)
691		852
692	Unlike the POSIX call of the same name, C<aio_readdir> reads an entire	853	Unlike the POSIX call of the same name, C<aio_readdir> reads an entire
…		…
1057	}	1218	}
1058		1219
1059	=item aio_rmtree $pathname, $callback->($status)	1220	=item aio_rmtree $pathname, $callback->($status)
1060		1221
1061	Delete a directory tree starting (and including) C<$path>, return the	1222	Delete a directory tree starting (and including) C<$path>, return the
1062	status of the final C<rmdir> only. This is a composite request that	1223	status of the final C<rmdir> only. This is a composite request that
1063	uses C<aio_scandir> to recurse into and rmdir directories, and unlink	1224	uses C<aio_scandir> to recurse into and rmdir directories, and unlink
1064	everything else.	1225	everything else.
1065		1226
1066	=cut	1227	=cut
1067		1228
…		…
1088	add $grp $dirgrp;	1249	add $grp $dirgrp;
1089	};	1250	};
1090		1251
1091	$grp	1252	$grp
1092	}	1253	}
		1254
		1255	=item aio_fcntl $fh, $cmd, $arg, $callback->($status)
		1256
		1257	=item aio_ioctl $fh, $request, $buf, $callback->($status)
		1258
		1259	These work just like the C<fcntl> and C<ioctl> built-in functions, except
		1260	they execute asynchronously and pass the return value to the callback.
		1261
		1262	Both calls can be used for a lot of things, some of which make more sense
		1263	to run asynchronously in their own thread, while some others make less
		1264	sense. For example, calls that block waiting for external events, such
		1265	as locking, will also lock down an I/O thread while it is waiting, which
		1266	can deadlock the whole I/O system. At the same time, there might be no
		1267	alternative to using a thread to wait.
		1268
		1269	So in general, you should only use these calls for things that do
		1270	(filesystem) I/O, not for things that wait for other events (network,
		1271	other processes), although if you are careful and know what you are doing,
		1272	you still can.
		1273
		1274	The following constants are available (missing ones are, as usual C<0>):
		1275
		1276	C<FIFREEZE>, C<FITHAW>, C<FITRIM>, C<FICLONE>, C<FICLONERANGE>, C<FIDEDUPERANGE>.
		1277
		1278	C<FS_IOC_GETFLAGS>, C<FS_IOC_SETFLAGS>, C<FS_IOC_GETVERSION>, C<FS_IOC_SETVERSION>,
		1279	C<FS_IOC_FIEMAP>.
		1280
		1281	C<FS_IOC_FSGETXATTR>, C<FS_IOC_FSSETXATTR>, C<FS_IOC_SET_ENCRYPTION_POLICY>,
		1282	C<FS_IOC_GET_ENCRYPTION_PWSALT>, C<FS_IOC_GET_ENCRYPTION_POLICY>, C<FS_KEY_DESCRIPTOR_SIZE>.
		1283
		1284	C<FS_SECRM_FL>, C<FS_UNRM_FL>, C<FS_COMPR_FL>, C<FS_SYNC_FL>, C<FS_IMMUTABLE_FL>,
		1285	C<FS_APPEND_FL>, C<FS_NODUMP_FL>, C<FS_NOATIME_FL>, C<FS_DIRTY_FL>,
		1286	C<FS_COMPRBLK_FL>, C<FS_NOCOMP_FL>, C<FS_ENCRYPT_FL>, C<FS_BTREE_FL>,
		1287	C<FS_INDEX_FL>, C<FS_JOURNAL_DATA_FL>, C<FS_NOTAIL_FL>, C<FS_DIRSYNC_FL>, C<FS_TOPDIR_FL>,
		1288	C<FS_FL_USER_MODIFIABLE>.
		1289
		1290	C<FS_XFLAG_REALTIME>, C<FS_XFLAG_PREALLOC>, C<FS_XFLAG_IMMUTABLE>, C<FS_XFLAG_APPEND>,
		1291	C<FS_XFLAG_SYNC>, C<FS_XFLAG_NOATIME>, C<FS_XFLAG_NODUMP>, C<FS_XFLAG_RTINHERIT>,
		1292	C<FS_XFLAG_PROJINHERIT>, C<FS_XFLAG_NOSYMLINKS>, C<FS_XFLAG_EXTSIZE>, C<FS_XFLAG_EXTSZINHERIT>,
		1293	C<FS_XFLAG_NODEFRAG>, C<FS_XFLAG_FILESTREAM>, C<FS_XFLAG_DAX>, C<FS_XFLAG_HASATTR>,
1093		1294
1094	=item aio_sync $callback->($status)	1295	=item aio_sync $callback->($status)
1095		1296
1096	Asynchronously call sync and call the callback when finished.	1297	Asynchronously call sync and call the callback when finished.
1097		1298
…		…
1166	};	1367	};
1167		1368
1168	$grp	1369	$grp
1169	}	1370	}
1170		1371
1171	=item aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)	1372	=item aio_msync $scalar, $offset = 0, $length = undef, flags = MS_SYNC, $callback->($status)
1172		1373
1173	This is a rather advanced IO::AIO call, which only works on mmap(2)ed	1374	This is a rather advanced IO::AIO call, which only works on mmap(2)ed
1174	scalars (see the C<IO::AIO::mmap> function, although it also works on data	1375	scalars (see the C<IO::AIO::mmap> function, although it also works on data
1175	scalars managed by the L<Sys::Mmap> or L<Mmap> modules, note that the	1376	scalars managed by the L<Sys::Mmap> or L<Mmap> modules, note that the
1176	scalar must only be modified in-place while an aio operation is pending on	1377	scalar must only be modified in-place while an aio operation is pending on
…		…
1178		1379
1179	It calls the C<msync> function of your OS, if available, with the memory	1380	It calls the C<msync> function of your OS, if available, with the memory
1180	area starting at C<$offset> in the string and ending C<$length> bytes	1381	area starting at C<$offset> in the string and ending C<$length> bytes
1181	later. If C<$length> is negative, counts from the end, and if C<$length>	1382	later. If C<$length> is negative, counts from the end, and if C<$length>
1182	is C<undef>, then it goes till the end of the string. The flags can be	1383	is C<undef>, then it goes till the end of the string. The flags can be
1183	a combination of C<IO::AIO::MS_ASYNC>, C<IO::AIO::MS_INVALIDATE> and	1384	either C<IO::AIO::MS_ASYNC> or C<IO::AIO::MS_SYNC>, plus an optional
1184	C<IO::AIO::MS_SYNC>.	1385	C<IO::AIO::MS_INVALIDATE>.
1185		1386
1186	=item aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)	1387	=item aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
1187		1388
1188	This is a rather advanced IO::AIO call, which works best on mmap(2)ed	1389	This is a rather advanced IO::AIO call, which works best on mmap(2)ed
1189	scalars.	1390	scalars.
1190		1391
1191	It touches (reads or writes) all memory pages in the specified	1392	It touches (reads or writes) all memory pages in the specified
1192	range inside the scalar. All caveats and parameters are the same	1393	range inside the scalar. All caveats and parameters are the same
1193	as for C<aio_msync>, above, except for flags, which must be either	1394	as for C<aio_msync>, above, except for flags, which must be either
1194	C<0> (which reads all pages and ensures they are instantiated) or	1395	C<0> (which reads all pages and ensures they are instantiated) or
1195	C<IO::AIO::MT_MODIFY>, which modifies the memory page s(by reading and	1396	C<IO::AIO::MT_MODIFY>, which modifies the memory pages (by reading and
1196	writing an octet from it, which dirties the page).	1397	writing an octet from it, which dirties the page).
1197		1398
1198	=item aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status)	1399	=item aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status)
1199		1400
1200	This is a rather advanced IO::AIO call, which works best on mmap(2)ed	1401	This is a rather advanced IO::AIO call, which works best on mmap(2)ed
…		…
1231	documented under L<MISCELLANEOUS FUNCTIONS>.	1432	documented under L<MISCELLANEOUS FUNCTIONS>.
1232		1433
1233	Example: asynchronously lock all current and future pages into memory.	1434	Example: asynchronously lock all current and future pages into memory.
1234		1435
1235	aio_mlockall IO::AIO::MCL_FUTURE;	1436	aio_mlockall IO::AIO::MCL_FUTURE;
		1437
		1438	=item aio_fiemap $fh, $start, $length, $flags, $count, $cb->(\@extents)
		1439
		1440	Queries the extents of the given file (by calling the Linux C<FIEMAP>
		1441	ioctl, see L<http://cvs.schmorp.de/IO-AIO/doc/fiemap.txt> for details). If
		1442	the ioctl is not available on your OS, then this request will fail with
		1443	C<ENOSYS>.
		1444
		1445	C<$start> is the starting offset to query extents for, C<$length> is the
		1446	size of the range to query - if it is C<undef>, then the whole file will
		1447	be queried.
		1448
		1449	C<$flags> is a combination of flags (C<IO::AIO::FIEMAP_FLAG_SYNC> or
		1450	C<IO::AIO::FIEMAP_FLAG_XATTR> - C<IO::AIO::FIEMAP_FLAGS_COMPAT> is also
		1451	exported), and is normally C<0> or C<IO::AIO::FIEMAP_FLAG_SYNC> to query
		1452	the data portion.
		1453
		1454	C<$count> is the maximum number of extent records to return. If it is
		1455	C<undef>, then IO::AIO queries all extents of the range. As a very special
		1456	case, if it is C<0>, then the callback receives the number of extents
		1457	instead of the extents themselves (which is unreliable, see below).
		1458
		1459	If an error occurs, the callback receives no arguments. The special
		1460	C<errno> value C<IO::AIO::EBADR> is available to test for flag errors.
		1461
		1462	Otherwise, the callback receives an array reference with extent
		1463	structures. Each extent structure is an array reference itself, with the
		1464	following members:
		1465
		1466	[$logical, $physical, $length, $flags]
		1467
		1468	Flags is any combination of the following flag values (typically either C<0>
		1469	or C<IO::AIO::FIEMAP_EXTENT_LAST> (1)):
		1470
		1471	C<IO::AIO::FIEMAP_EXTENT_LAST>, C<IO::AIO::FIEMAP_EXTENT_UNKNOWN>,
		1472	C<IO::AIO::FIEMAP_EXTENT_DELALLOC>, C<IO::AIO::FIEMAP_EXTENT_ENCODED>,
		1473	C<IO::AIO::FIEMAP_EXTENT_DATA_ENCRYPTED>, C<IO::AIO::FIEMAP_EXTENT_NOT_ALIGNED>,
		1474	C<IO::AIO::FIEMAP_EXTENT_DATA_INLINE>, C<IO::AIO::FIEMAP_EXTENT_DATA_TAIL>,
		1475	C<IO::AIO::FIEMAP_EXTENT_UNWRITTEN>, C<IO::AIO::FIEMAP_EXTENT_MERGED> or
		1476	C<IO::AIO::FIEMAP_EXTENT_SHARED>.
		1477
		1478	At the time of this writing (Linux 3.2), this requets is unreliable unless
		1479	C<$count> is C<undef>, as the kernel has all sorts of bugs preventing
		1480	it to return all extents of a range for files with large number of
		1481	extents. The code works around all these issues if C<$count> is undef.
1236		1482
1237	=item aio_group $callback->(...)	1483	=item aio_group $callback->(...)
1238		1484
1239	This is a very special aio request: Instead of doing something, it is a	1485	This is a very special aio request: Instead of doing something, it is a
1240	container for other aio requests, which is useful if you want to bundle	1486	container for other aio requests, which is useful if you want to bundle
…		…
1324	aio_stat [$etcdir, "passwd"], sub {	1570	aio_stat [$etcdir, "passwd"], sub {
1325	# yay	1571	# yay
1326	};	1572	};
1327	};	1573	};
1328		1574
1329	That C<aio_wd> is a request and not a normal function shows that creating	1575	The fact that C<aio_wd> is a request and not a normal function shows that
1330	an IO::AIO::WD object is itself a potentially blocking operation, which is	1576	creating an IO::AIO::WD object is itself a potentially blocking operation,
1331	why it is done asynchronously.	1577	which is why it is done asynchronously.
1332		1578
1333	To stat the directory obtained with C<aio_wd> above, one could write	1579	To stat the directory obtained with C<aio_wd> above, one could write
1334	either of the following three request calls:	1580	either of the following three request calls:
1335		1581
1336	aio_lstat "/etc" , sub { ... # pathname as normal string	1582	aio_lstat "/etc" , sub { ... # pathname as normal string
…		…
1356	will still point to the original directory. Most functions accepting a	1602	will still point to the original directory. Most functions accepting a
1357	pathname will use the directory fd on newer systems, and the string on	1603	pathname will use the directory fd on newer systems, and the string on
1358	older systems. Some functions (such as realpath) will always rely on the	1604	older systems. Some functions (such as realpath) will always rely on the
1359	string form of the pathname.	1605	string form of the pathname.
1360		1606
1361	So this fucntionality is mainly useful to get some protection against	1607	So this functionality is mainly useful to get some protection against
1362	C<chdir>, to easily get an absolute path out of a relative path for future	1608	C<chdir>, to easily get an absolute path out of a relative path for future
1363	reference, and to speed up doing many operations in the same directory	1609	reference, and to speed up doing many operations in the same directory
1364	(e.g. when stat'ing all files in a directory).	1610	(e.g. when stat'ing all files in a directory).
1365		1611
1366	The following functions implement this working directory abstraction:	1612	The following functions implement this working directory abstraction:
…		…
1379	passing C<undef> as working directory component of a pathname fails the	1625	passing C<undef> as working directory component of a pathname fails the
1380	request with C<ENOENT>, there is often no need for error checking in the	1626	request with C<ENOENT>, there is often no need for error checking in the
1381	C<aio_wd> callback, as future requests using the value will fail in the	1627	C<aio_wd> callback, as future requests using the value will fail in the
1382	expected way.	1628	expected way.
1383		1629
1384	If this call isn't available because your OS lacks it or it couldn't be
1385	detected, it will be emulated by calling C<fsync> instead.
1386
1387	=item IO::AIO::CWD	1630	=item IO::AIO::CWD
1388		1631
1389	This is a compiletime constant (object) that represents the process	1632	This is a compiletime constant (object) that represents the process
1390	current working directory.	1633	current working directory.
1391		1634
1392	Specifying this object as working directory object for a pathname is as	1635	Specifying this object as working directory object for a pathname is as if
1393	if the pathname would be specified directly, without a directory object,	1636	the pathname would be specified directly, without a directory object. For
1394	e.g., these calls are functionally identical:	1637	example, these calls are functionally identical:
1395		1638
1396	aio_stat "somefile", sub { ... };	1639	aio_stat "somefile", sub { ... };
1397	aio_stat [IO::AIO::CWD, "somefile"], sub { ... };	1640	aio_stat [IO::AIO::CWD, "somefile"], sub { ... };
1398		1641
1399	=back	1642	=back
1400		1643
		1644	To recover the path associated with an IO::AIO::WD object, you can use
		1645	C<aio_realpath>:
		1646
		1647	aio_realpath $wd, sub {
		1648	warn "path is $_[0]\n";
		1649	};
		1650
		1651	Currently, C<aio_statvfs> always, and C<aio_rename> and C<aio_rmdir>
		1652	sometimes, fall back to using an absolue path.
1401		1653
1402	=head2 IO::AIO::REQ CLASS	1654	=head2 IO::AIO::REQ CLASS
1403		1655
1404	All non-aggregate C<aio_*> functions return an object of this class when	1656	All non-aggregate C<aio_*> functions return an object of this class when
1405	called in non-void context.	1657	called in non-void context.
…		…
1583		1835
1584	See C<poll_cb> for an example.	1836	See C<poll_cb> for an example.
1585		1837
1586	=item IO::AIO::poll_cb	1838	=item IO::AIO::poll_cb
1587		1839
1588	Process some outstanding events on the result pipe. You have to call	1840	Process some requests that have reached the result phase (i.e. they have
		1841	been executed but the results are not yet reported). You have to call
		1842	this "regularly" to finish outstanding requests.
		1843
1589	this regularly. Returns C<0> if all events could be processed (or there	1844	Returns C<0> if all events could be processed (or there were no
1590	were no events to process), or C<-1> if it returned earlier for whatever	1845	events to process), or C<-1> if it returned earlier for whatever
1591	reason. Returns immediately when no events are outstanding. The amount of	1846	reason. Returns immediately when no events are outstanding. The amount
1592	events processed depends on the settings of C<IO::AIO::max_poll_req> and	1847	of events processed depends on the settings of C<IO::AIO::max_poll_req>,
1593	C<IO::AIO::max_poll_time>.	1848	C<IO::AIO::max_poll_time> and C<IO::AIO::max_outstanding>.
1594		1849
1595	If not all requests were processed for whatever reason, the filehandle	1850	If not all requests were processed for whatever reason, the poll file
1596	will still be ready when C<poll_cb> returns, so normally you don't have to	1851	descriptor will still be ready when C<poll_cb> returns, so normally you
1597	do anything special to have it called later.	1852	don't have to do anything special to have it called later.
1598		1853
1599	Apart from calling C<IO::AIO::poll_cb> when the event filehandle becomes	1854	Apart from calling C<IO::AIO::poll_cb> when the event filehandle becomes
1600	ready, it can be beneficial to call this function from loops which submit	1855	ready, it can be beneficial to call this function from loops which submit
1601	a lot of requests, to make sure the results get processed when they become	1856	a lot of requests, to make sure the results get processed when they become
1602	available and not just when the loop is finished and the event loop takes	1857	available and not just when the loop is finished and the event loop takes
…		…
1611	poll => 'r', async => 1,	1866	poll => 'r', async => 1,
1612	cb => \&IO::AIO::poll_cb);	1867	cb => \&IO::AIO::poll_cb);
1613		1868
1614	=item IO::AIO::poll_wait	1869	=item IO::AIO::poll_wait
1615		1870
1616	If there are any outstanding requests and none of them in the result	1871	Wait until either at least one request is in the result phase or no
1617	phase, wait till the result filehandle becomes ready for reading (simply	1872	requests are outstanding anymore.
1618	does a C<select> on the filehandle. This is useful if you want to	1873
1619	synchronously wait for some requests to finish).	1874	This is useful if you want to synchronously wait for some requests to
		1875	become ready, without actually handling them.
1620		1876
1621	See C<nreqs> for an example.	1877	See C<nreqs> for an example.
1622		1878
1623	=item IO::AIO::poll	1879	=item IO::AIO::poll
1624		1880
…		…
1745		2001
1746	This is a very bad function to use in interactive programs because it	2002	This is a very bad function to use in interactive programs because it
1747	blocks, and a bad way to reduce concurrency because it is inexact: Better	2003	blocks, and a bad way to reduce concurrency because it is inexact: Better
1748	use an C<aio_group> together with a feed callback.	2004	use an C<aio_group> together with a feed callback.
1749		2005
1750	It's main use is in scripts without an event loop - when you want to stat	2006	Its main use is in scripts without an event loop - when you want to stat
1751	a lot of files, you can write somehting like this:	2007	a lot of files, you can write somehting like this:
1752		2008
1753	IO::AIO::max_outstanding 32;	2009	IO::AIO::max_outstanding 32;
1754		2010
1755	for my $path (...) {	2011	for my $path (...) {
…		…
1795		2051
1796	=back	2052	=back
1797		2053
1798	=head3 MISCELLANEOUS FUNCTIONS	2054	=head3 MISCELLANEOUS FUNCTIONS
1799		2055
1800	IO::AIO implements some functions that might be useful, but are not	2056	IO::AIO implements some functions that are useful when you want to use
1801	asynchronous.	2057	some "Advanced I/O" function not available to in Perl, without going the
		2058	"Asynchronous I/O" route. Many of these have an asynchronous C<aio_*>
		2059	counterpart.
1802		2060
1803	=over 4	2061	=over 4
1804		2062
1805	=item IO::AIO::sendfile $ofh, $ifh, $offset, $count	2063	=item IO::AIO::sendfile $ofh, $ifh, $offset, $count
1806		2064
…		…
1825	=item IO::AIO::madvise $scalar, $offset, $len, $advice	2083	=item IO::AIO::madvise $scalar, $offset, $len, $advice
1826		2084
1827	Simply calls the C<posix_madvise> function (see its	2085	Simply calls the C<posix_madvise> function (see its
1828	manpage for details). The following advice constants are	2086	manpage for details). The following advice constants are
1829	available: C<IO::AIO::MADV_NORMAL>, C<IO::AIO::MADV_SEQUENTIAL>,	2087	available: C<IO::AIO::MADV_NORMAL>, C<IO::AIO::MADV_SEQUENTIAL>,
1830	C<IO::AIO::MADV_RANDOM>, C<IO::AIO::MADV_WILLNEED>, C<IO::AIO::MADV_DONTNEED>.	2088	C<IO::AIO::MADV_RANDOM>, C<IO::AIO::MADV_WILLNEED>, C<IO::AIO::MADV_DONTNEED>,
		2089	C<IO::AIO::MADV_FREE>.
		2090
		2091	If C<$offset> is negative, counts from the end. If C<$length> is negative,
		2092	the remaining length of the C<$scalar> is used. If possible, C<$length>
		2093	will be reduced to fit into the C<$scalar>.
1831		2094
1832	On systems that do not implement C<posix_madvise>, this function returns	2095	On systems that do not implement C<posix_madvise>, this function returns
1833	ENOSYS, otherwise the return value of C<posix_madvise>.	2096	ENOSYS, otherwise the return value of C<posix_madvise>.
1834		2097
1835	=item IO::AIO::mprotect $scalar, $offset, $len, $protect	2098	=item IO::AIO::mprotect $scalar, $offset, $len, $protect
…		…
1837	Simply calls the C<mprotect> function on the preferably AIO::mmap'ed	2100	Simply calls the C<mprotect> function on the preferably AIO::mmap'ed
1838	$scalar (see its manpage for details). The following protect	2101	$scalar (see its manpage for details). The following protect
1839	constants are available: C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_READ>,	2102	constants are available: C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_READ>,
1840	C<IO::AIO::PROT_WRITE>, C<IO::AIO::PROT_EXEC>.	2103	C<IO::AIO::PROT_WRITE>, C<IO::AIO::PROT_EXEC>.
1841		2104
		2105	If C<$offset> is negative, counts from the end. If C<$length> is negative,
		2106	the remaining length of the C<$scalar> is used. If possible, C<$length>
		2107	will be reduced to fit into the C<$scalar>.
		2108
1842	On systems that do not implement C<mprotect>, this function returns	2109	On systems that do not implement C<mprotect>, this function returns
1843	ENOSYS, otherwise the return value of C<mprotect>.	2110	ENOSYS, otherwise the return value of C<mprotect>.
1844		2111
1845	=item IO::AIO::mmap $scalar, $length, $prot, $flags, $fh[, $offset]	2112	=item IO::AIO::mmap $scalar, $length, $prot, $flags, $fh[, $offset]
1846		2113
1847	Memory-maps a file (or anonymous memory range) and attaches it to the	2114	Memory-maps a file (or anonymous memory range) and attaches it to the
1848	given C<$scalar>, which will act like a string scalar.	2115	given C<$scalar>, which will act like a string scalar. Returns true on
		2116	success, and false otherwise.
1849		2117
		2118	The scalar must exist, but its contents do not matter - this means you
		2119	cannot use a nonexistant array or hash element. When in doubt, C<undef>
		2120	the scalar first.
		2121
1850	The only operations allowed on the scalar are C<substr>/C<vec> that don't	2122	The only operations allowed on the mmapped scalar are C<substr>/C<vec>,
1851	change the string length, and most read-only operations such as copying it	2123	which don't change the string length, and most read-only operations such
1852	or searching it with regexes and so on.	2124	as copying it or searching it with regexes and so on.
1853		2125
1854	Anything else is unsafe and will, at best, result in memory leaks.	2126	Anything else is unsafe and will, at best, result in memory leaks.
1855		2127
1856	The memory map associated with the C<$scalar> is automatically removed	2128	The memory map associated with the C<$scalar> is automatically removed
1857	when the C<$scalar> is destroyed, or when the C<IO::AIO::mmap> or	2129	when the C<$scalar> is undef'd or destroyed, or when the C<IO::AIO::mmap>
1858	C<IO::AIO::munmap> functions are called.	2130	or C<IO::AIO::munmap> functions are called on it.
1859		2131
1860	This calls the C<mmap>(2) function internally. See your system's manual	2132	This calls the C<mmap>(2) function internally. See your system's manual
1861	page for details on the C<$length>, C<$prot> and C<$flags> parameters.	2133	page for details on the C<$length>, C<$prot> and C<$flags> parameters.
1862		2134
1863	The C<$length> must be larger than zero and smaller than the actual	2135	The C<$length> must be larger than zero and smaller than the actual
1864	filesize.	2136	filesize.
1865		2137
1866	C<$prot> is a combination of C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_EXEC>,	2138	C<$prot> is a combination of C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_EXEC>,
1867	C<IO::AIO::PROT_READ> and/or C<IO::AIO::PROT_WRITE>,	2139	C<IO::AIO::PROT_READ> and/or C<IO::AIO::PROT_WRITE>,
1868		2140
1869	C<$flags> can be a combination of C<IO::AIO::MAP_SHARED> or	2141	C<$flags> can be a combination of
1870	C<IO::AIO::MAP_PRIVATE>, or a number of system-specific flags (when	2142	C<IO::AIO::MAP_SHARED> or
1871	not available, the are defined as 0): C<IO::AIO::MAP_ANONYMOUS>	2143	C<IO::AIO::MAP_PRIVATE>,
		2144	or a number of system-specific flags (when not available, the are C<0>):
1872	(which is set to C<MAP_ANON> if your system only provides this	2145	C<IO::AIO::MAP_ANONYMOUS> (which is set to C<MAP_ANON> if your system only provides this constant),
1873	constant), C<IO::AIO::MAP_HUGETLB>, C<IO::AIO::MAP_LOCKED>,	2146	C<IO::AIO::MAP_LOCKED>,
1874	C<IO::AIO::MAP_NORESERVE>, C<IO::AIO::MAP_POPULATE> or	2147	C<IO::AIO::MAP_NORESERVE>,
		2148	C<IO::AIO::MAP_POPULATE>,
1875	C<IO::AIO::MAP_NONBLOCK>	2149	C<IO::AIO::MAP_NONBLOCK>,
		2150	C<IO::AIO::MAP_FIXED>,
		2151	C<IO::AIO::MAP_GROWSDOWN>,
		2152	C<IO::AIO::MAP_32BIT>,
		2153	C<IO::AIO::MAP_HUGETLB> or
		2154	C<IO::AIO::MAP_STACK>.
1876		2155
1877	If C<$fh> is C<undef>, then a file descriptor of C<-1> is passed.	2156	If C<$fh> is C<undef>, then a file descriptor of C<-1> is passed.
1878		2157
1879	C<$offset> is the offset from the start of the file - it generally must be	2158	C<$offset> is the offset from the start of the file - it generally must be
1880	a multiple of C<IO::AIO::PAGESIZE> and defaults to C<0>.	2159	a multiple of C<IO::AIO::PAGESIZE> and defaults to C<0>.
…		…
1905		2184
1906	Calls the C<munlockall> function.	2185	Calls the C<munlockall> function.
1907		2186
1908	On systems that do not implement C<munlockall>, this function returns	2187	On systems that do not implement C<munlockall>, this function returns
1909	ENOSYS, otherwise the return value of C<munlockall>.	2188	ENOSYS, otherwise the return value of C<munlockall>.
		2189
		2190	=item IO::AIO::splice $r_fh, $r_off, $w_fh, $w_off, $length, $flags
		2191
		2192	Calls the GNU/Linux C<splice(2)> syscall, if available. If C<$r_off> or
		2193	C<$w_off> are C<undef>, then C<NULL> is passed for these, otherwise they
		2194	should be the file offset.
		2195
		2196	C<$r_fh> and C<$w_fh> should not refer to the same file, as splice might
		2197	silently corrupt the data in this case.
		2198
		2199	The following symbol flag values are available: C<IO::AIO::SPLICE_F_MOVE>,
		2200	C<IO::AIO::SPLICE_F_NONBLOCK>, C<IO::AIO::SPLICE_F_MORE> and
		2201	C<IO::AIO::SPLICE_F_GIFT>.
		2202
		2203	See the C<splice(2)> manpage for details.
		2204
		2205	=item IO::AIO::tee $r_fh, $w_fh, $length, $flags
		2206
		2207	Calls the GNU/Linux C<tee(2)> syscall, see its manpage and the
		2208	description for C<IO::AIO::splice> above for details.
		2209
		2210	=item $actual_size = IO::AIO::pipesize $r_fh[, $new_size]
		2211
		2212	Attempts to query or change the pipe buffer size. Obviously works only
		2213	on pipes, and currently works only on GNU/Linux systems, and fails with
		2214	C<-1>/C<ENOSYS> everywhere else. If anybody knows how to influence pipe buffer
		2215	size on other systems, drop me a note.
		2216
		2217	=item ($rfh, $wfh) = IO::AIO::pipe2 [$flags]
		2218
		2219	This is a direct interface to the Linux L<pipe2(2)> system call. If
		2220	C<$flags> is missing or C<0>, then this should be the same as a call to
		2221	perl's built-in C<pipe> function and create a new pipe, and works on
		2222	systems that lack the pipe2 syscall. On win32, this case invokes C<_pipe
		2223	(..., 4096, O_BINARY)>.
		2224
		2225	If C<$flags> is non-zero, it tries to invoke the pipe2 system call with
		2226	the given flags (Linux 2.6.27, glibc 2.9).
		2227
		2228	On success, the read and write file handles are returned.
		2229
		2230	On error, nothing will be returned. If the pipe2 syscall is missing and
		2231	C<$flags> is non-zero, fails with C<ENOSYS>.
		2232
		2233	Please refer to L<pipe2(2)> for more info on the C<$flags>, but at the
		2234	time of this writing, C<IO::AIO::O_CLOEXEC>, C<IO::AIO::O_NONBLOCK> and
		2235	C<IO::AIO::O_DIRECT> (Linux 3.4, for packet-based pipes) were supported.
1910		2236
1911	=back	2237	=back
1912		2238
1913	=cut	2239	=cut
1914		2240

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Comparing IO-AIO/AIO.pm (file contents): Revision 1.218 by root, Fri Dec 30 07:52:12 2011 UTC vs. Revision 1.270 by root, Fri Jun 23 03:23:19 2017 UTC

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Comparing IO-AIO/AIO.pm (file contents):
Revision 1.218 by root, Fri Dec 30 07:52:12 2011 UTC vs.
Revision 1.270 by root, Fri Jun 23 03:23:19 2017 UTC