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

Comparing IO-AIO/AIO.pm (file contents):
Revision 1.220 by root, Sun Apr 1 17:46:02 2012 UTC vs.
Revision 1.279 by root, Sat Jan 6 01:04:42 2018 UTC

…		…
1	=head1 NAME	1	=head1 NAME
2		2
3	IO::AIO - Asynchronous Input/Output	3	IO::AIO - Asynchronous/Advanced Input/Output
4		4
5	=head1 SYNOPSIS	5	=head1 SYNOPSIS
6		6
7	use IO::AIO;	7	use IO::AIO;
8		8
58	not well-supported or restricted (GNU/Linux doesn't allow them on normal	58	not well-supported or restricted (GNU/Linux doesn't allow them on normal
59	files currently, for example), and they would only support aio_read and	59	files currently, for example), and they would only support aio_read and
60	aio_write, so the remaining functionality would have to be implemented	60	aio_write, so the remaining functionality would have to be implemented
61	using threads anyway.	61	using threads anyway.
62		62
		63	In addition to asynchronous I/O, this module also exports some rather
		64	arcane interfaces, such as C<madvise> or linux's C<splice> system call,
		65	which is why the C<A> in C<AIO> can also mean I<advanced>.
		66
63	Although the module will work in the presence of other (Perl-) threads,	67	Although the module will work in the presence of other (Perl-) threads,
64	it is currently not reentrant in any way, so use appropriate locking	68	it is currently not reentrant in any way, so use appropriate locking
65	yourself, always call C<poll_cb> from within the same thread, or never	69	yourself, always call C<poll_cb> from within the same thread, or never
66	call C<poll_cb> (or other C<aio_> functions) recursively.	70	call C<poll_cb> (or other C<aio_> functions) recursively.
67		71
68	=head2 EXAMPLE	72	=head2 EXAMPLE
69		73
70	This is a simple example that uses the EV module and loads	74	This is a simple example that uses the EV module and loads
71	F</etc/passwd> asynchronously:	75	F</etc/passwd> asynchronously:
72		76
73	use Fcntl;
74	use EV;	77	use EV;
75	use IO::AIO;	78	use IO::AIO;
76		79
77	# register the IO::AIO callback with EV	80	# register the IO::AIO callback with EV
78	my $aio_w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb;	81	my $aio_w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb;
…		…
95		98
96	# file contents now in $contents	99	# file contents now in $contents
97	print $contents;	100	print $contents;
98		101
99	# exit event loop and program	102	# exit event loop and program
100	EV::unloop;	103	EV::break;
101	};	104	};
102	};	105	};
103		106
104	# possibly queue up other requests, or open GUI windows,	107	# possibly queue up other requests, or open GUI windows,
105	# check for sockets etc. etc.	108	# check for sockets etc. etc.
106		109
107	# process events as long as there are some:	110	# process events as long as there are some:
108	EV::loop;	111	EV::run;
109		112
110	=head1 REQUEST ANATOMY AND LIFETIME	113	=head1 REQUEST ANATOMY AND LIFETIME
111		114
112	Every C<aio_*> function creates a request. which is a C data structure not	115	Every C<aio_*> function creates a request. which is a C data structure not
113	directly visible to Perl.	116	directly visible to Perl.
…		…
168	use common::sense;	171	use common::sense;
169		172
170	use base 'Exporter';	173	use base 'Exporter';
171		174
172	BEGIN {	175	BEGIN {
173	our $VERSION = '4.13';	176	our $VERSION = 4.4;
174		177
175	our @AIO_REQ = qw(aio_sendfile aio_seek aio_read aio_write aio_open aio_close	178	our @AIO_REQ = qw(aio_sendfile aio_seek aio_read aio_write aio_open aio_close
176	aio_stat aio_lstat aio_unlink aio_rmdir aio_readdir aio_readdirx	179	aio_stat aio_lstat aio_unlink aio_rmdir aio_readdir aio_readdirx
177	aio_scandir aio_symlink aio_readlink aio_realpath aio_sync	180	aio_scandir aio_symlink aio_readlink aio_realpath aio_fcntl aio_ioctl
178	aio_fsync aio_syncfs aio_fdatasync aio_sync_file_range aio_fallocate	181	aio_sync aio_fsync aio_syncfs aio_fdatasync aio_sync_file_range
179	aio_pathsync aio_readahead	182	aio_pathsync aio_readahead aio_fiemap aio_allocate
180	aio_rename aio_link aio_move aio_copy aio_group	183	aio_rename aio_rename2 aio_link aio_move aio_copy aio_group
181	aio_nop aio_mknod aio_load aio_rmtree aio_mkdir aio_chown	184	aio_nop aio_mknod aio_load aio_rmtree aio_mkdir aio_chown
182	aio_chmod aio_utime aio_truncate	185	aio_chmod aio_utime aio_truncate
183	aio_msync aio_mtouch aio_mlock aio_mlockall	186	aio_msync aio_mtouch aio_mlock aio_mlockall
184	aio_statvfs	187	aio_statvfs
		188	aio_slurp
185	aio_wd);	189	aio_wd);
186		190
187	our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice));	191	our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice));
188	our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush	192	our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush
189	min_parallel max_parallel max_idle idle_timeout	193	min_parallel max_parallel max_idle idle_timeout
…		…
202		206
203	=head1 FUNCTIONS	207	=head1 FUNCTIONS
204		208
205	=head2 QUICK OVERVIEW	209	=head2 QUICK OVERVIEW
206		210
207	This section simply lists the prototypes of the most important functions	211	This section simply lists the prototypes most of the functions for
208	for quick reference. See the following sections for function-by-function	212	quick reference. See the following sections for function-by-function
209	documentation.	213	documentation.
210		214
211	aio_wd $pathname, $callback->($wd)	215	aio_wd $pathname, $callback->($wd)
212	aio_open $pathname, $flags, $mode, $callback->($fh)	216	aio_open $pathname, $flags, $mode, $callback->($fh)
213	aio_close $fh, $callback->($status)	217	aio_close $fh, $callback->($status)
…		…
221	aio_statvfs $fh_or_path, $callback->($statvfs)	225	aio_statvfs $fh_or_path, $callback->($statvfs)
222	aio_utime $fh_or_path, $atime, $mtime, $callback->($status)	226	aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
223	aio_chown $fh_or_path, $uid, $gid, $callback->($status)	227	aio_chown $fh_or_path, $uid, $gid, $callback->($status)
224	aio_chmod $fh_or_path, $mode, $callback->($status)	228	aio_chmod $fh_or_path, $mode, $callback->($status)
225	aio_truncate $fh_or_path, $offset, $callback->($status)	229	aio_truncate $fh_or_path, $offset, $callback->($status)
		230	aio_allocate $fh, $mode, $offset, $len, $callback->($status)
		231	aio_fiemap $fh, $start, $length, $flags, $count, $cb->(\@extents)
226	aio_unlink $pathname, $callback->($status)	232	aio_unlink $pathname, $callback->($status)
227	aio_mknod $pathname, $mode, $dev, $callback->($status)	233	aio_mknod $pathname, $mode, $dev, $callback->($status)
228	aio_link $srcpath, $dstpath, $callback->($status)	234	aio_link $srcpath, $dstpath, $callback->($status)
229	aio_symlink $srcpath, $dstpath, $callback->($status)	235	aio_symlink $srcpath, $dstpath, $callback->($status)
230	aio_readlink $pathname, $callback->($link)	236	aio_readlink $pathname, $callback->($link)
231	aio_realpath $pathname, $callback->($link)	237	aio_realpath $pathname, $callback->($path)
232	aio_rename $srcpath, $dstpath, $callback->($status)	238	aio_rename $srcpath, $dstpath, $callback->($status)
		239	aio_rename2 $srcpath, $dstpath, $flags, $callback->($status)
233	aio_mkdir $pathname, $mode, $callback->($status)	240	aio_mkdir $pathname, $mode, $callback->($status)
234	aio_rmdir $pathname, $callback->($status)	241	aio_rmdir $pathname, $callback->($status)
235	aio_readdir $pathname, $callback->($entries)	242	aio_readdir $pathname, $callback->($entries)
236	aio_readdirx $pathname, $flags, $callback->($entries, $flags)	243	aio_readdirx $pathname, $flags, $callback->($entries, $flags)
237	IO::AIO::READDIR_DENTS IO::AIO::READDIR_DIRS_FIRST	244	IO::AIO::READDIR_DENTS IO::AIO::READDIR_DIRS_FIRST
…		…
239	aio_scandir $pathname, $maxreq, $callback->($dirs, $nondirs)	246	aio_scandir $pathname, $maxreq, $callback->($dirs, $nondirs)
240	aio_load $pathname, $data, $callback->($status)	247	aio_load $pathname, $data, $callback->($status)
241	aio_copy $srcpath, $dstpath, $callback->($status)	248	aio_copy $srcpath, $dstpath, $callback->($status)
242	aio_move $srcpath, $dstpath, $callback->($status)	249	aio_move $srcpath, $dstpath, $callback->($status)
243	aio_rmtree $pathname, $callback->($status)	250	aio_rmtree $pathname, $callback->($status)
		251	aio_fcntl $fh, $cmd, $arg, $callback->($status)
		252	aio_ioctl $fh, $request, $buf, $callback->($status)
244	aio_sync $callback->($status)	253	aio_sync $callback->($status)
245	aio_syncfs $fh, $callback->($status)	254	aio_syncfs $fh, $callback->($status)
246	aio_fsync $fh, $callback->($status)	255	aio_fsync $fh, $callback->($status)
247	aio_fdatasync $fh, $callback->($status)	256	aio_fdatasync $fh, $callback->($status)
248	aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status)	257	aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status)
249	aio_pathsync $pathname, $callback->($status)	258	aio_pathsync $pathname, $callback->($status)
250	aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)	259	aio_msync $scalar, $offset = 0, $length = undef, flags = MS_SYNC, $callback->($status)
251	aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)	260	aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
252	aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status)	261	aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status)
253	aio_mlockall $flags, $callback->($status)	262	aio_mlockall $flags, $callback->($status)
254	aio_group $callback->(...)	263	aio_group $callback->(...)
255	aio_nop $callback->()	264	aio_nop $callback->()
…		…
269	IO::AIO::idle_timeout $seconds	278	IO::AIO::idle_timeout $seconds
270	IO::AIO::max_outstanding $maxreqs	279	IO::AIO::max_outstanding $maxreqs
271	IO::AIO::nreqs	280	IO::AIO::nreqs
272	IO::AIO::nready	281	IO::AIO::nready
273	IO::AIO::npending	282	IO::AIO::npending
		283	$nfd = IO::AIO::get_fdlimit [EXPERIMENTAL]
		284	IO::AIO::min_fdlimit $nfd [EXPERIMENTAL]
274		285
275	IO::AIO::sendfile $ofh, $ifh, $offset, $count	286	IO::AIO::sendfile $ofh, $ifh, $offset, $count
276	IO::AIO::fadvise $fh, $offset, $len, $advice	287	IO::AIO::fadvise $fh, $offset, $len, $advice
		288	IO::AIO::mmap $scalar, $length, $prot, $flags[, $fh[, $offset]]
		289	IO::AIO::munmap $scalar
277	IO::AIO::madvise $scalar, $offset, $length, $advice	290	IO::AIO::madvise $scalar, $offset, $length, $advice
278	IO::AIO::mprotect $scalar, $offset, $length, $protect	291	IO::AIO::mprotect $scalar, $offset, $length, $protect
279	IO::AIO::munlock $scalar, $offset = 0, $length = undef	292	IO::AIO::munlock $scalar, $offset = 0, $length = undef
280	IO::AIO::munlockall	293	IO::AIO::munlockall
281		294
…		…
358		371
359		372
360	=item aio_open $pathname, $flags, $mode, $callback->($fh)	373	=item aio_open $pathname, $flags, $mode, $callback->($fh)
361		374
362	Asynchronously open or create a file and call the callback with a newly	375	Asynchronously open or create a file and call the callback with a newly
363	created filehandle for the file.	376	created filehandle for the file (or C<undef> in case of an error).
364		377
365	The pathname passed to C<aio_open> must be absolute. See API NOTES, above,	378	The pathname passed to C<aio_open> must be absolute. See API NOTES, above,
366	for an explanation.	379	for an explanation.
367		380
368	The C<$flags> argument is a bitmask. See the C<Fcntl> module for a	381	The C<$flags> argument is a bitmask. See the C<Fcntl> module for a
…		…
391	following POSIX and non-POSIX constants are available (missing ones on	404	following POSIX and non-POSIX constants are available (missing ones on
392	your system are, as usual, C<0>):	405	your system are, as usual, C<0>):
393		406
394	C<O_ASYNC>, C<O_DIRECT>, C<O_NOATIME>, C<O_CLOEXEC>, C<O_NOCTTY>, C<O_NOFOLLOW>,	407	C<O_ASYNC>, C<O_DIRECT>, C<O_NOATIME>, C<O_CLOEXEC>, C<O_NOCTTY>, C<O_NOFOLLOW>,
395	C<O_NONBLOCK>, C<O_EXEC>, C<O_SEARCH>, C<O_DIRECTORY>, C<O_DSYNC>,	408	C<O_NONBLOCK>, C<O_EXEC>, C<O_SEARCH>, C<O_DIRECTORY>, C<O_DSYNC>,
396	C<O_RSYNC>, C<O_SYNC> and C<O_TTY_INIT>.	409	C<O_RSYNC>, C<O_SYNC>, C<O_PATH>, C<O_TMPFILE>, and C<O_TTY_INIT>.
397		410
398		411
399	=item aio_close $fh, $callback->($status)	412	=item aio_close $fh, $callback->($status)
400		413
401	Asynchronously close a file and call the callback with the result	414	Asynchronously close a file and call the callback with the result
…		…
413		426
414	=cut	427	=cut
415		428
416	=item aio_seek $fh, $offset, $whence, $callback->($offs)	429	=item aio_seek $fh, $offset, $whence, $callback->($offs)
417		430
418	Seeks the filehandle to the new C<$offset>, similarly to perl'S	431	Seeks the filehandle to the new C<$offset>, similarly to perl's
419	C<sysseek>. The C<$whence> can use the traditional values (C<0> for	432	C<sysseek>. The C<$whence> can use the traditional values (C<0> for
420	C<IO::AIO::SEEK_SET>, C<1> for C<IO::AIO::SEEK_CUR> or C<2> for	433	C<IO::AIO::SEEK_SET>, C<1> for C<IO::AIO::SEEK_CUR> or C<2> for
421	C<IO::AIO::SEEK_END>).	434	C<IO::AIO::SEEK_END>).
422		435
423	The resulting absolute offset will be passed to the callback, or C<-1> in	436	The resulting absolute offset will be passed to the callback, or C<-1> in
…		…
425		438
426	In theory, the C<$whence> constants could be different than the	439	In theory, the C<$whence> constants could be different than the
427	corresponding values from L<Fcntl>, but perl guarantees they are the same,	440	corresponding values from L<Fcntl>, but perl guarantees they are the same,
428	so don't panic.	441	so don't panic.
429		442
		443	As a GNU/Linux (and maybe Solaris) extension, also the constants
		444	C<IO::AIO::SEEK_DATA> and C<IO::AIO::SEEK_HOLE> are available, if they
		445	could be found. No guarantees about suitability for use in C<aio_seek> or
		446	Perl's C<sysseek> can be made though, although I would naively assume they
		447	"just work".
		448
430	=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)	449	=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
431		450
432	=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)	451	=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
433		452
434	Reads or writes C<$length> bytes from or to the specified C<$fh> and	453	Reads or writes C<$length> bytes from or to the specified C<$fh> and
435	C<$offset> into the scalar given by C<$data> and offset C<$dataoffset>	454	C<$offset> into the scalar given by C<$data> and offset C<$dataoffset> and
436	and calls the callback without the actual number of bytes read (or -1 on	455	calls the callback with the actual number of bytes transferred (or -1 on
437	error, just like the syscall).	456	error, just like the syscall).
438		457
439	C<aio_read> will, like C<sysread>, shrink or grow the C<$data> scalar to	458	C<aio_read> will, like C<sysread>, shrink or grow the C<$data> scalar to
440	offset plus the actual number of bytes read.	459	offset plus the actual number of bytes read.
441		460
…		…
499	As native sendfile syscalls (as practically any non-POSIX interface hacked	518	As native sendfile syscalls (as practically any non-POSIX interface hacked
500	together in a hurry to improve benchmark numbers) tend to be rather buggy	519	together in a hurry to improve benchmark numbers) tend to be rather buggy
501	on many systems, this implementation tries to work around some known bugs	520	on many systems, this implementation tries to work around some known bugs
502	in Linux and FreeBSD kernels (probably others, too), but that might fail,	521	in Linux and FreeBSD kernels (probably others, too), but that might fail,
503	so you really really should check the return value of C<aio_sendfile> -	522	so you really really should check the return value of C<aio_sendfile> -
504	fewre bytes than expected might have been transferred.	523	fewer bytes than expected might have been transferred.
505		524
506		525
507	=item aio_readahead $fh,$offset,$length, $callback->($retval)	526	=item aio_readahead $fh,$offset,$length, $callback->($retval)
508		527
509	C<aio_readahead> populates the page cache with data from a file so that	528	C<aio_readahead> populates the page cache with data from a file so that
…		…
513	whole pages, so that offset is effectively rounded down to a page boundary	532	whole pages, so that offset is effectively rounded down to a page boundary
514	and bytes are read up to the next page boundary greater than or equal to	533	and bytes are read up to the next page boundary greater than or equal to
515	(off-set+length). C<aio_readahead> does not read beyond the end of the	534	(off-set+length). C<aio_readahead> does not read beyond the end of the
516	file. The current file offset of the file is left unchanged.	535	file. The current file offset of the file is left unchanged.
517		536
518	If that syscall doesn't exist (likely if your OS isn't Linux) it will be	537	If that syscall doesn't exist (likely if your kernel isn't Linux) it will
519	emulated by simply reading the data, which would have a similar effect.	538	be emulated by simply reading the data, which would have a similar effect.
520		539
521		540
522	=item aio_stat $fh_or_path, $callback->($status)	541	=item aio_stat $fh_or_path, $callback->($status)
523		542
524	=item aio_lstat $fh, $callback->($status)	543	=item aio_lstat $fh, $callback->($status)
…		…
593	namemax => 255,	612	namemax => 255,
594	frsize => 1024,	613	frsize => 1024,
595	fsid => 1810	614	fsid => 1810
596	}	615	}
597		616
		617	Here is a (likely partial - send me updates!) list of fsid values used by
		618	Linux - it is safe to hardcode these when C<$^O> is C<linux>:
		619
		620	0x0000adf5 adfs
		621	0x0000adff affs
		622	0x5346414f afs
		623	0x09041934 anon-inode filesystem
		624	0x00000187 autofs
		625	0x42465331 befs
		626	0x1badface bfs
		627	0x42494e4d binfmt_misc
		628	0x9123683e btrfs
		629	0x0027e0eb cgroupfs
		630	0xff534d42 cifs
		631	0x73757245 coda
		632	0x012ff7b7 coh
		633	0x28cd3d45 cramfs
		634	0x453dcd28 cramfs-wend (wrong endianness)
		635	0x64626720 debugfs
		636	0x00001373 devfs
		637	0x00001cd1 devpts
		638	0x0000f15f ecryptfs
		639	0x00414a53 efs
		640	0x0000137d ext
		641	0x0000ef53 ext2/ext3/ext4
		642	0x0000ef51 ext2
		643	0xf2f52010 f2fs
		644	0x00004006 fat
		645	0x65735546 fuseblk
		646	0x65735543 fusectl
		647	0x0bad1dea futexfs
		648	0x01161970 gfs2
		649	0x47504653 gpfs
		650	0x00004244 hfs
		651	0xf995e849 hpfs
		652	0x00c0ffee hostfs
		653	0x958458f6 hugetlbfs
		654	0x2bad1dea inotifyfs
		655	0x00009660 isofs
		656	0x000072b6 jffs2
		657	0x3153464a jfs
		658	0x6b414653 k-afs
		659	0x0bd00bd0 lustre
		660	0x0000137f minix
		661	0x0000138f minix 30 char names
		662	0x00002468 minix v2
		663	0x00002478 minix v2 30 char names
		664	0x00004d5a minix v3
		665	0x19800202 mqueue
		666	0x00004d44 msdos
		667	0x0000564c novell
		668	0x00006969 nfs
		669	0x6e667364 nfsd
		670	0x00003434 nilfs
		671	0x5346544e ntfs
		672	0x00009fa1 openprom
		673	0x7461636F ocfs2
		674	0x00009fa0 proc
		675	0x6165676c pstorefs
		676	0x0000002f qnx4
		677	0x68191122 qnx6
		678	0x858458f6 ramfs
		679	0x52654973 reiserfs
		680	0x00007275 romfs
		681	0x67596969 rpc_pipefs
		682	0x73636673 securityfs
		683	0xf97cff8c selinux
		684	0x0000517b smb
		685	0x534f434b sockfs
		686	0x73717368 squashfs
		687	0x62656572 sysfs
		688	0x012ff7b6 sysv2
		689	0x012ff7b5 sysv4
		690	0x01021994 tmpfs
		691	0x15013346 udf
		692	0x00011954 ufs
		693	0x54190100 ufs byteswapped
		694	0x00009fa2 usbdevfs
		695	0x01021997 v9fs
		696	0xa501fcf5 vxfs
		697	0xabba1974 xenfs
		698	0x012ff7b4 xenix
		699	0x58465342 xfs
		700	0x012fd16d xia
598		701
599	=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status)	702	=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
600		703
601	Works like perl's C<utime> function (including the special case of $atime	704	Works like perl's C<utime> function (including the special case of $atime
602	and $mtime being undef). Fractional times are supported if the underlying	705	and $mtime being undef). Fractional times are supported if the underlying
…		…
630	=item aio_truncate $fh_or_path, $offset, $callback->($status)	733	=item aio_truncate $fh_or_path, $offset, $callback->($status)
631		734
632	Works like truncate(2) or ftruncate(2).	735	Works like truncate(2) or ftruncate(2).
633		736
634		737
		738	=item aio_allocate $fh, $mode, $offset, $len, $callback->($status)
		739
		740	Allocates or frees disk space according to the C<$mode> argument. See the
		741	linux C<fallocate> documentation for details.
		742
		743	C<$mode> is usually C<0> or C<IO::AIO::FALLOC_FL_KEEP_SIZE> to allocate
		744	space, or C<IO::AIO::FALLOC_FL_PUNCH_HOLE \| IO::AIO::FALLOC_FL_KEEP_SIZE>,
		745	to deallocate a file range.
		746
		747	IO::AIO also supports C<FALLOC_FL_COLLAPSE_RANGE>, to remove a range
		748	(without leaving a hole), C<FALLOC_FL_ZERO_RANGE>, to zero a range,
		749	C<FALLOC_FL_INSERT_RANGE> to insert a range and C<FALLOC_FL_UNSHARE_RANGE>
		750	to unshare shared blocks (see your L<fallocate(2)> manpage).
		751
		752	The file system block size used by C<fallocate> is presumably the
		753	C<f_bsize> returned by C<statvfs>, but different filesystems and filetypes
		754	can dictate other limitations.
		755
		756	If C<fallocate> isn't available or cannot be emulated (currently no
		757	emulation will be attempted), passes C<-1> and sets C<$!> to C<ENOSYS>.
		758
		759
635	=item aio_chmod $fh_or_path, $mode, $callback->($status)	760	=item aio_chmod $fh_or_path, $mode, $callback->($status)
636		761
637	Works like perl's C<chmod> function.	762	Works like perl's C<chmod> function.
638		763
639		764
…		…
676		801
677		802
678	=item aio_realpath $pathname, $callback->($path)	803	=item aio_realpath $pathname, $callback->($path)
679		804
680	Asynchronously make the path absolute and resolve any symlinks in	805	Asynchronously make the path absolute and resolve any symlinks in
681	C<$path>. The resulting path only consists of directories (Same as	806	C<$path>. The resulting path only consists of directories (same as
682	L<Cwd::realpath>).	807	L<Cwd::realpath>).
683		808
684	This request can be used to get the absolute path of the current working	809	This request can be used to get the absolute path of the current working
685	directory by passing it a path of F<.> (a single dot).	810	directory by passing it a path of F<.> (a single dot).
686		811
687		812
688	=item aio_rename $srcpath, $dstpath, $callback->($status)	813	=item aio_rename $srcpath, $dstpath, $callback->($status)
689		814
690	Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as	815	Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as
691	rename(2) and call the callback with the result code.	816	rename(2) and call the callback with the result code.
		817
		818	On systems that support the AIO::WD working directory abstraction
		819	natively, the case C<[$wd, "."]> as C<$srcpath> is specialcased - instead
		820	of failing, C<rename> is called on the absolute path of C<$wd>.
		821
		822
		823	=item aio_rename2 $srcpath, $dstpath, $flags, $callback->($status)
		824
		825	Basically a version of C<aio_rename> with an additional C<$flags>
		826	argument. Calling this with C<$flags=0> is the same as calling
		827	C<aio_rename>.
		828
		829	Non-zero flags are currently only supported on GNU/Linux systems that
		830	support renameat2. Other systems fail with C<ENOSYS> in this case.
		831
		832	The following constants are available (missing ones are, as usual C<0>),
		833	see renameat2(2) for details:
		834
		835	C<IO::AIO::RENAME_NOREPLACE>, C<IO::AIO::RENAME_EXCHANGE>
		836	and C<IO::AIO::RENAME_WHITEOUT>.
692		837
693		838
694	=item aio_mkdir $pathname, $mode, $callback->($status)	839	=item aio_mkdir $pathname, $mode, $callback->($status)
695		840
696	Asynchronously mkdir (create) a directory and call the callback with	841	Asynchronously mkdir (create) a directory and call the callback with
…		…
700		845
701	=item aio_rmdir $pathname, $callback->($status)	846	=item aio_rmdir $pathname, $callback->($status)
702		847
703	Asynchronously rmdir (delete) a directory and call the callback with the	848	Asynchronously rmdir (delete) a directory and call the callback with the
704	result code.	849	result code.
		850
		851	On systems that support the AIO::WD working directory abstraction
		852	natively, the case C<[$wd, "."]> is specialcased - instead of failing,
		853	C<rmdir> is called on the absolute path of C<$wd>.
705		854
706		855
707	=item aio_readdir $pathname, $callback->($entries)	856	=item aio_readdir $pathname, $callback->($entries)
708		857
709	Unlike the POSIX call of the same name, C<aio_readdir> reads an entire	858	Unlike the POSIX call of the same name, C<aio_readdir> reads an entire
…		…
778	C<$type>'s are known, which can be used to speed up some algorithms.	927	C<$type>'s are known, which can be used to speed up some algorithms.
779		928
780	=back	929	=back
781		930
782		931
		932	=item aio_slurp $pathname, $offset, $length, $data, $callback->($status)
		933
		934	Opens, reads and closes the given file. The data is put into C<$data>,
		935	which is resized as required.
		936
		937	If C<$offset> is negative, then it is counted from the end of the file.
		938
		939	If C<$length> is zero, then the remaining length of the file is
		940	used. Also, in this case, the same limitations to modifying C<$data> apply
		941	as when IO::AIO::mmap is used, i.e. it must only be modified in-place
		942	with C<substr>. If the size of the file is known, specifying a non-zero
		943	C<$length> results in a performance advantage.
		944
		945	This request is similar to the older C<aio_load> request, but since it is
		946	a single request, it might be more efficient to use.
		947
		948	Example: load F</etc/passwd> into C<$passwd>.
		949
		950	my $passwd;
		951	aio_slurp "/etc/passwd", 0, 0, $passwd, sub {
		952	$_[0] >= 0
		953	or die "/etc/passwd: $!\n";
		954
		955	printf "/etc/passwd is %d bytes long, and contains:\n", length $passwd;
		956	print $passwd;
		957	};
		958	IO::AIO::flush;
		959
		960
783	=item aio_load $pathname, $data, $callback->($status)	961	=item aio_load $pathname, $data, $callback->($status)
784		962
785	This is a composite request that tries to fully load the given file into	963	This is a composite request that tries to fully load the given file into
786	memory. Status is the same as with aio_read.	964	memory. Status is the same as with aio_read.
		965
		966	Using C<aio_slurp> might be more efficient, as it is a single request.
787		967
788	=cut	968	=cut
789		969
790	sub aio_load($$;$) {	970	sub aio_load($$;$) {
791	my ($path, undef, $cb) = @_;	971	my ($path, undef, $cb) = @_;
…		…
811	=item aio_copy $srcpath, $dstpath, $callback->($status)	991	=item aio_copy $srcpath, $dstpath, $callback->($status)
812		992
813	Try to copy the I<file> (directories not supported as either source or	993	Try to copy the I<file> (directories not supported as either source or
814	destination) from C<$srcpath> to C<$dstpath> and call the callback with	994	destination) from C<$srcpath> to C<$dstpath> and call the callback with
815	a status of C<0> (ok) or C<-1> (error, see C<$!>).	995	a status of C<0> (ok) or C<-1> (error, see C<$!>).
		996
		997	Existing destination files will be truncated.
816		998
817	This is a composite request that creates the destination file with	999	This is a composite request that creates the destination file with
818	mode 0200 and copies the contents of the source file into it using	1000	mode 0200 and copies the contents of the source file into it using
819	C<aio_sendfile>, followed by restoring atime, mtime, access mode and	1001	C<aio_sendfile>, followed by restoring atime, mtime, access mode and
820	uid/gid, in that order.	1002	uid/gid, in that order.
…		…
930	Scans a directory (similar to C<aio_readdir>) but additionally tries to	1112	Scans a directory (similar to C<aio_readdir>) but additionally tries to
931	efficiently separate the entries of directory C<$path> into two sets of	1113	efficiently separate the entries of directory C<$path> into two sets of
932	names, directories you can recurse into (directories), and ones you cannot	1114	names, directories you can recurse into (directories), and ones you cannot
933	recurse into (everything else, including symlinks to directories).	1115	recurse into (everything else, including symlinks to directories).
934		1116
935	C<aio_scandir> is a composite request that creates of many sub requests_	1117	C<aio_scandir> is a composite request that generates many sub requests.
936	C<$maxreq> specifies the maximum number of outstanding aio requests that	1118	C<$maxreq> specifies the maximum number of outstanding aio requests that
937	this function generates. If it is C<< <= 0 >>, then a suitable default	1119	this function generates. If it is C<< <= 0 >>, then a suitable default
938	will be chosen (currently 4).	1120	will be chosen (currently 4).
939		1121
940	On error, the callback is called without arguments, otherwise it receives	1122	On error, the callback is called without arguments, otherwise it receives
…		…
1074	}	1256	}
1075		1257
1076	=item aio_rmtree $pathname, $callback->($status)	1258	=item aio_rmtree $pathname, $callback->($status)
1077		1259
1078	Delete a directory tree starting (and including) C<$path>, return the	1260	Delete a directory tree starting (and including) C<$path>, return the
1079	status of the final C<rmdir> only. This is a composite request that	1261	status of the final C<rmdir> only. This is a composite request that
1080	uses C<aio_scandir> to recurse into and rmdir directories, and unlink	1262	uses C<aio_scandir> to recurse into and rmdir directories, and unlink
1081	everything else.	1263	everything else.
1082		1264
1083	=cut	1265	=cut
1084		1266
…		…
1105	add $grp $dirgrp;	1287	add $grp $dirgrp;
1106	};	1288	};
1107		1289
1108	$grp	1290	$grp
1109	}	1291	}
		1292
		1293	=item aio_fcntl $fh, $cmd, $arg, $callback->($status)
		1294
		1295	=item aio_ioctl $fh, $request, $buf, $callback->($status)
		1296
		1297	These work just like the C<fcntl> and C<ioctl> built-in functions, except
		1298	they execute asynchronously and pass the return value to the callback.
		1299
		1300	Both calls can be used for a lot of things, some of which make more sense
		1301	to run asynchronously in their own thread, while some others make less
		1302	sense. For example, calls that block waiting for external events, such
		1303	as locking, will also lock down an I/O thread while it is waiting, which
		1304	can deadlock the whole I/O system. At the same time, there might be no
		1305	alternative to using a thread to wait.
		1306
		1307	So in general, you should only use these calls for things that do
		1308	(filesystem) I/O, not for things that wait for other events (network,
		1309	other processes), although if you are careful and know what you are doing,
		1310	you still can.
		1311
		1312	The following constants are available (missing ones are, as usual C<0>):
		1313
		1314	C<F_DUPFD_CLOEXEC>,
		1315
		1316	C<F_OFD_GETLK>, C<F_OFD_SETLK>, C<F_OFD_GETLKW>,
		1317
		1318	C<FIFREEZE>, C<FITHAW>, C<FITRIM>, C<FICLONE>, C<FICLONERANGE>, C<FIDEDUPERANGE>.
		1319
		1320	C<FS_IOC_GETFLAGS>, C<FS_IOC_SETFLAGS>, C<FS_IOC_GETVERSION>, C<FS_IOC_SETVERSION>,
		1321	C<FS_IOC_FIEMAP>.
		1322
		1323	C<FS_IOC_FSGETXATTR>, C<FS_IOC_FSSETXATTR>, C<FS_IOC_SET_ENCRYPTION_POLICY>,
		1324	C<FS_IOC_GET_ENCRYPTION_PWSALT>, C<FS_IOC_GET_ENCRYPTION_POLICY>, C<FS_KEY_DESCRIPTOR_SIZE>.
		1325
		1326	C<FS_SECRM_FL>, C<FS_UNRM_FL>, C<FS_COMPR_FL>, C<FS_SYNC_FL>, C<FS_IMMUTABLE_FL>,
		1327	C<FS_APPEND_FL>, C<FS_NODUMP_FL>, C<FS_NOATIME_FL>, C<FS_DIRTY_FL>,
		1328	C<FS_COMPRBLK_FL>, C<FS_NOCOMP_FL>, C<FS_ENCRYPT_FL>, C<FS_BTREE_FL>,
		1329	C<FS_INDEX_FL>, C<FS_JOURNAL_DATA_FL>, C<FS_NOTAIL_FL>, C<FS_DIRSYNC_FL>, C<FS_TOPDIR_FL>,
		1330	C<FS_FL_USER_MODIFIABLE>.
		1331
		1332	C<FS_XFLAG_REALTIME>, C<FS_XFLAG_PREALLOC>, C<FS_XFLAG_IMMUTABLE>, C<FS_XFLAG_APPEND>,
		1333	C<FS_XFLAG_SYNC>, C<FS_XFLAG_NOATIME>, C<FS_XFLAG_NODUMP>, C<FS_XFLAG_RTINHERIT>,
		1334	C<FS_XFLAG_PROJINHERIT>, C<FS_XFLAG_NOSYMLINKS>, C<FS_XFLAG_EXTSIZE>, C<FS_XFLAG_EXTSZINHERIT>,
		1335	C<FS_XFLAG_NODEFRAG>, C<FS_XFLAG_FILESTREAM>, C<FS_XFLAG_DAX>, C<FS_XFLAG_HASATTR>,
1110		1336
1111	=item aio_sync $callback->($status)	1337	=item aio_sync $callback->($status)
1112		1338
1113	Asynchronously call sync and call the callback when finished.	1339	Asynchronously call sync and call the callback when finished.
1114		1340
…		…
1183	};	1409	};
1184		1410
1185	$grp	1411	$grp
1186	}	1412	}
1187		1413
1188	=item aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)	1414	=item aio_msync $scalar, $offset = 0, $length = undef, flags = MS_SYNC, $callback->($status)
1189		1415
1190	This is a rather advanced IO::AIO call, which only works on mmap(2)ed	1416	This is a rather advanced IO::AIO call, which only works on mmap(2)ed
1191	scalars (see the C<IO::AIO::mmap> function, although it also works on data	1417	scalars (see the C<IO::AIO::mmap> function, although it also works on data
1192	scalars managed by the L<Sys::Mmap> or L<Mmap> modules, note that the	1418	scalars managed by the L<Sys::Mmap> or L<Mmap> modules, note that the
1193	scalar must only be modified in-place while an aio operation is pending on	1419	scalar must only be modified in-place while an aio operation is pending on
…		…
1195		1421
1196	It calls the C<msync> function of your OS, if available, with the memory	1422	It calls the C<msync> function of your OS, if available, with the memory
1197	area starting at C<$offset> in the string and ending C<$length> bytes	1423	area starting at C<$offset> in the string and ending C<$length> bytes
1198	later. If C<$length> is negative, counts from the end, and if C<$length>	1424	later. If C<$length> is negative, counts from the end, and if C<$length>
1199	is C<undef>, then it goes till the end of the string. The flags can be	1425	is C<undef>, then it goes till the end of the string. The flags can be
1200	a combination of C<IO::AIO::MS_ASYNC>, C<IO::AIO::MS_INVALIDATE> and	1426	either C<IO::AIO::MS_ASYNC> or C<IO::AIO::MS_SYNC>, plus an optional
1201	C<IO::AIO::MS_SYNC>.	1427	C<IO::AIO::MS_INVALIDATE>.
1202		1428
1203	=item aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)	1429	=item aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
1204		1430
1205	This is a rather advanced IO::AIO call, which works best on mmap(2)ed	1431	This is a rather advanced IO::AIO call, which works best on mmap(2)ed
1206	scalars.	1432	scalars.
1207		1433
1208	It touches (reads or writes) all memory pages in the specified	1434	It touches (reads or writes) all memory pages in the specified
1209	range inside the scalar. All caveats and parameters are the same	1435	range inside the scalar. All caveats and parameters are the same
1210	as for C<aio_msync>, above, except for flags, which must be either	1436	as for C<aio_msync>, above, except for flags, which must be either
1211	C<0> (which reads all pages and ensures they are instantiated) or	1437	C<0> (which reads all pages and ensures they are instantiated) or
1212	C<IO::AIO::MT_MODIFY>, which modifies the memory page s(by reading and	1438	C<IO::AIO::MT_MODIFY>, which modifies the memory pages (by reading and
1213	writing an octet from it, which dirties the page).	1439	writing an octet from it, which dirties the page).
1214		1440
1215	=item aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status)	1441	=item aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status)
1216		1442
1217	This is a rather advanced IO::AIO call, which works best on mmap(2)ed	1443	This is a rather advanced IO::AIO call, which works best on mmap(2)ed
…		…
1248	documented under L<MISCELLANEOUS FUNCTIONS>.	1474	documented under L<MISCELLANEOUS FUNCTIONS>.
1249		1475
1250	Example: asynchronously lock all current and future pages into memory.	1476	Example: asynchronously lock all current and future pages into memory.
1251		1477
1252	aio_mlockall IO::AIO::MCL_FUTURE;	1478	aio_mlockall IO::AIO::MCL_FUTURE;
		1479
		1480	=item aio_fiemap $fh, $start, $length, $flags, $count, $cb->(\@extents)
		1481
		1482	Queries the extents of the given file (by calling the Linux C<FIEMAP>
		1483	ioctl, see L<http://cvs.schmorp.de/IO-AIO/doc/fiemap.txt> for details). If
		1484	the ioctl is not available on your OS, then this request will fail with
		1485	C<ENOSYS>.
		1486
		1487	C<$start> is the starting offset to query extents for, C<$length> is the
		1488	size of the range to query - if it is C<undef>, then the whole file will
		1489	be queried.
		1490
		1491	C<$flags> is a combination of flags (C<IO::AIO::FIEMAP_FLAG_SYNC> or
		1492	C<IO::AIO::FIEMAP_FLAG_XATTR> - C<IO::AIO::FIEMAP_FLAGS_COMPAT> is also
		1493	exported), and is normally C<0> or C<IO::AIO::FIEMAP_FLAG_SYNC> to query
		1494	the data portion.
		1495
		1496	C<$count> is the maximum number of extent records to return. If it is
		1497	C<undef>, then IO::AIO queries all extents of the range. As a very special
		1498	case, if it is C<0>, then the callback receives the number of extents
		1499	instead of the extents themselves (which is unreliable, see below).
		1500
		1501	If an error occurs, the callback receives no arguments. The special
		1502	C<errno> value C<IO::AIO::EBADR> is available to test for flag errors.
		1503
		1504	Otherwise, the callback receives an array reference with extent
		1505	structures. Each extent structure is an array reference itself, with the
		1506	following members:
		1507
		1508	[$logical, $physical, $length, $flags]
		1509
		1510	Flags is any combination of the following flag values (typically either C<0>
		1511	or C<IO::AIO::FIEMAP_EXTENT_LAST> (1)):
		1512
		1513	C<IO::AIO::FIEMAP_EXTENT_LAST>, C<IO::AIO::FIEMAP_EXTENT_UNKNOWN>,
		1514	C<IO::AIO::FIEMAP_EXTENT_DELALLOC>, C<IO::AIO::FIEMAP_EXTENT_ENCODED>,
		1515	C<IO::AIO::FIEMAP_EXTENT_DATA_ENCRYPTED>, C<IO::AIO::FIEMAP_EXTENT_NOT_ALIGNED>,
		1516	C<IO::AIO::FIEMAP_EXTENT_DATA_INLINE>, C<IO::AIO::FIEMAP_EXTENT_DATA_TAIL>,
		1517	C<IO::AIO::FIEMAP_EXTENT_UNWRITTEN>, C<IO::AIO::FIEMAP_EXTENT_MERGED> or
		1518	C<IO::AIO::FIEMAP_EXTENT_SHARED>.
		1519
		1520	At the time of this writing (Linux 3.2), this request is unreliable unless
		1521	C<$count> is C<undef>, as the kernel has all sorts of bugs preventing
		1522	it to return all extents of a range for files with a large number of
		1523	extents. The code (only) works around all these issues if C<$count> is
		1524	C<undef>.
1253		1525
1254	=item aio_group $callback->(...)	1526	=item aio_group $callback->(...)
1255		1527
1256	This is a very special aio request: Instead of doing something, it is a	1528	This is a very special aio request: Instead of doing something, it is a
1257	container for other aio requests, which is useful if you want to bundle	1529	container for other aio requests, which is useful if you want to bundle
…		…
1341	aio_stat [$etcdir, "passwd"], sub {	1613	aio_stat [$etcdir, "passwd"], sub {
1342	# yay	1614	# yay
1343	};	1615	};
1344	};	1616	};
1345		1617
1346	That C<aio_wd> is a request and not a normal function shows that creating	1618	The fact that C<aio_wd> is a request and not a normal function shows that
1347	an IO::AIO::WD object is itself a potentially blocking operation, which is	1619	creating an IO::AIO::WD object is itself a potentially blocking operation,
1348	why it is done asynchronously.	1620	which is why it is done asynchronously.
1349		1621
1350	To stat the directory obtained with C<aio_wd> above, one could write	1622	To stat the directory obtained with C<aio_wd> above, one could write
1351	either of the following three request calls:	1623	either of the following three request calls:
1352		1624
1353	aio_lstat "/etc" , sub { ... # pathname as normal string	1625	aio_lstat "/etc" , sub { ... # pathname as normal string
…		…
1370	There are some caveats: when directories get renamed (or deleted), the	1642	There are some caveats: when directories get renamed (or deleted), the
1371	pathname string doesn't change, so will point to the new directory (or	1643	pathname string doesn't change, so will point to the new directory (or
1372	nowhere at all), while the directory fd, if available on the system,	1644	nowhere at all), while the directory fd, if available on the system,
1373	will still point to the original directory. Most functions accepting a	1645	will still point to the original directory. Most functions accepting a
1374	pathname will use the directory fd on newer systems, and the string on	1646	pathname will use the directory fd on newer systems, and the string on
1375	older systems. Some functions (such as realpath) will always rely on the	1647	older systems. Some functions (such as C<aio_realpath>) will always rely on
1376	string form of the pathname.	1648	the string form of the pathname.
1377		1649
1378	So this fucntionality is mainly useful to get some protection against	1650	So this functionality is mainly useful to get some protection against
1379	C<chdir>, to easily get an absolute path out of a relative path for future	1651	C<chdir>, to easily get an absolute path out of a relative path for future
1380	reference, and to speed up doing many operations in the same directory	1652	reference, and to speed up doing many operations in the same directory
1381	(e.g. when stat'ing all files in a directory).	1653	(e.g. when stat'ing all files in a directory).
1382		1654
1383	The following functions implement this working directory abstraction:	1655	The following functions implement this working directory abstraction:
…		…
1396	passing C<undef> as working directory component of a pathname fails the	1668	passing C<undef> as working directory component of a pathname fails the
1397	request with C<ENOENT>, there is often no need for error checking in the	1669	request with C<ENOENT>, there is often no need for error checking in the
1398	C<aio_wd> callback, as future requests using the value will fail in the	1670	C<aio_wd> callback, as future requests using the value will fail in the
1399	expected way.	1671	expected way.
1400		1672
1401	If this call isn't available because your OS lacks it or it couldn't be
1402	detected, it will be emulated by calling C<fsync> instead.
1403
1404	=item IO::AIO::CWD	1673	=item IO::AIO::CWD
1405		1674
1406	This is a compiletime constant (object) that represents the process	1675	This is a compiletime constant (object) that represents the process
1407	current working directory.	1676	current working directory.
1408		1677
1409	Specifying this object as working directory object for a pathname is as	1678	Specifying this object as working directory object for a pathname is as if
1410	if the pathname would be specified directly, without a directory object,	1679	the pathname would be specified directly, without a directory object. For
1411	e.g., these calls are functionally identical:	1680	example, these calls are functionally identical:
1412		1681
1413	aio_stat "somefile", sub { ... };	1682	aio_stat "somefile", sub { ... };
1414	aio_stat [IO::AIO::CWD, "somefile"], sub { ... };	1683	aio_stat [IO::AIO::CWD, "somefile"], sub { ... };
1415		1684
1416	=back	1685	=back
1417		1686
		1687	To recover the path associated with an IO::AIO::WD object, you can use
		1688	C<aio_realpath>:
		1689
		1690	aio_realpath $wd, sub {
		1691	warn "path is $_[0]\n";
		1692	};
		1693
		1694	Currently, C<aio_statvfs> always, and C<aio_rename> and C<aio_rmdir>
		1695	sometimes, fall back to using an absolue path.
1418		1696
1419	=head2 IO::AIO::REQ CLASS	1697	=head2 IO::AIO::REQ CLASS
1420		1698
1421	All non-aggregate C<aio_*> functions return an object of this class when	1699	All non-aggregate C<aio_*> functions return an object of this class when
1422	called in non-void context.	1700	called in non-void context.
…		…
1600		1878
1601	See C<poll_cb> for an example.	1879	See C<poll_cb> for an example.
1602		1880
1603	=item IO::AIO::poll_cb	1881	=item IO::AIO::poll_cb
1604		1882
1605	Process some outstanding events on the result pipe. You have to call	1883	Process some requests that have reached the result phase (i.e. they have
		1884	been executed but the results are not yet reported). You have to call
		1885	this "regularly" to finish outstanding requests.
		1886
1606	this regularly. Returns C<0> if all events could be processed (or there	1887	Returns C<0> if all events could be processed (or there were no
1607	were no events to process), or C<-1> if it returned earlier for whatever	1888	events to process), or C<-1> if it returned earlier for whatever
1608	reason. Returns immediately when no events are outstanding. The amount of	1889	reason. Returns immediately when no events are outstanding. The amount
1609	events processed depends on the settings of C<IO::AIO::max_poll_req> and	1890	of events processed depends on the settings of C<IO::AIO::max_poll_req>,
1610	C<IO::AIO::max_poll_time>.	1891	C<IO::AIO::max_poll_time> and C<IO::AIO::max_outstanding>.
1611		1892
1612	If not all requests were processed for whatever reason, the filehandle	1893	If not all requests were processed for whatever reason, the poll file
1613	will still be ready when C<poll_cb> returns, so normally you don't have to	1894	descriptor will still be ready when C<poll_cb> returns, so normally you
1614	do anything special to have it called later.	1895	don't have to do anything special to have it called later.
1615		1896
1616	Apart from calling C<IO::AIO::poll_cb> when the event filehandle becomes	1897	Apart from calling C<IO::AIO::poll_cb> when the event filehandle becomes
1617	ready, it can be beneficial to call this function from loops which submit	1898	ready, it can be beneficial to call this function from loops which submit
1618	a lot of requests, to make sure the results get processed when they become	1899	a lot of requests, to make sure the results get processed when they become
1619	available and not just when the loop is finished and the event loop takes	1900	available and not just when the loop is finished and the event loop takes
…		…
1628	poll => 'r', async => 1,	1909	poll => 'r', async => 1,
1629	cb => \&IO::AIO::poll_cb);	1910	cb => \&IO::AIO::poll_cb);
1630		1911
1631	=item IO::AIO::poll_wait	1912	=item IO::AIO::poll_wait
1632		1913
1633	If there are any outstanding requests and none of them in the result	1914	Wait until either at least one request is in the result phase or no
1634	phase, wait till the result filehandle becomes ready for reading (simply	1915	requests are outstanding anymore.
1635	does a C<select> on the filehandle. This is useful if you want to	1916
1636	synchronously wait for some requests to finish).	1917	This is useful if you want to synchronously wait for some requests to
		1918	become ready, without actually handling them.
1637		1919
1638	See C<nreqs> for an example.	1920	See C<nreqs> for an example.
1639		1921
1640	=item IO::AIO::poll	1922	=item IO::AIO::poll
1641		1923
…		…
1762		2044
1763	This is a very bad function to use in interactive programs because it	2045	This is a very bad function to use in interactive programs because it
1764	blocks, and a bad way to reduce concurrency because it is inexact: Better	2046	blocks, and a bad way to reduce concurrency because it is inexact: Better
1765	use an C<aio_group> together with a feed callback.	2047	use an C<aio_group> together with a feed callback.
1766		2048
1767	It's main use is in scripts without an event loop - when you want to stat	2049	Its main use is in scripts without an event loop - when you want to stat
1768	a lot of files, you can write somehting like this:	2050	a lot of files, you can write something like this:
1769		2051
1770	IO::AIO::max_outstanding 32;	2052	IO::AIO::max_outstanding 32;
1771		2053
1772	for my $path (...) {	2054	for my $path (...) {
1773	aio_stat $path , ...;	2055	aio_stat $path , ...;
…		…
1812		2094
1813	=back	2095	=back
1814		2096
1815	=head3 MISCELLANEOUS FUNCTIONS	2097	=head3 MISCELLANEOUS FUNCTIONS
1816		2098
1817	IO::AIO implements some functions that might be useful, but are not	2099	IO::AIO implements some functions that are useful when you want to use
1818	asynchronous.	2100	some "Advanced I/O" function not available to in Perl, without going the
		2101	"Asynchronous I/O" route. Many of these have an asynchronous C<aio_*>
		2102	counterpart.
1819		2103
1820	=over 4	2104	=over 4
		2105
		2106	=item $numfd = IO::AIO::get_fdlimit
		2107
		2108	This function is I<EXPERIMENTAL> and subject to change.
		2109
		2110	Tries to find the current file descriptor limit and returns it, or
		2111	C<undef> and sets C<$!> in case of an error. The limit is one larger than
		2112	the highest valid file descriptor number.
		2113
		2114	=item IO::AIO::min_fdlimit [$numfd]
		2115
		2116	This function is I<EXPERIMENTAL> and subject to change.
		2117
		2118	Try to increase the current file descriptor limit(s) to at least C<$numfd>
		2119	by changing the soft or hard file descriptor resource limit. If C<$numfd>
		2120	is missing, it will try to set a very high limit, although this is not
		2121	recommended when you know the actual minimum that you require.
		2122
		2123	If the limit cannot be raised enough, the function makes a best-effort
		2124	attempt to increase the limit as much as possible, using various
		2125	tricks, while still failing. You can query the resulting limit using
		2126	C<IO::AIO::get_fdlimit>.
		2127
		2128	If an error occurs, returns C<undef> and sets C<$!>, otherwise returns
		2129	true.
1821		2130
1822	=item IO::AIO::sendfile $ofh, $ifh, $offset, $count	2131	=item IO::AIO::sendfile $ofh, $ifh, $offset, $count
1823		2132
1824	Calls the C<eio_sendfile_sync> function, which is like C<aio_sendfile>,	2133	Calls the C<eio_sendfile_sync> function, which is like C<aio_sendfile>,
1825	but is blocking (this makes most sense if you know the input data is	2134	but is blocking (this makes most sense if you know the input data is
…		…
1842	=item IO::AIO::madvise $scalar, $offset, $len, $advice	2151	=item IO::AIO::madvise $scalar, $offset, $len, $advice
1843		2152
1844	Simply calls the C<posix_madvise> function (see its	2153	Simply calls the C<posix_madvise> function (see its
1845	manpage for details). The following advice constants are	2154	manpage for details). The following advice constants are
1846	available: C<IO::AIO::MADV_NORMAL>, C<IO::AIO::MADV_SEQUENTIAL>,	2155	available: C<IO::AIO::MADV_NORMAL>, C<IO::AIO::MADV_SEQUENTIAL>,
1847	C<IO::AIO::MADV_RANDOM>, C<IO::AIO::MADV_WILLNEED>, C<IO::AIO::MADV_DONTNEED>.	2156	C<IO::AIO::MADV_RANDOM>, C<IO::AIO::MADV_WILLNEED>,
		2157	C<IO::AIO::MADV_DONTNEED>.
		2158
		2159	If C<$offset> is negative, counts from the end. If C<$length> is negative,
		2160	the remaining length of the C<$scalar> is used. If possible, C<$length>
		2161	will be reduced to fit into the C<$scalar>.
1848		2162
1849	On systems that do not implement C<posix_madvise>, this function returns	2163	On systems that do not implement C<posix_madvise>, this function returns
1850	ENOSYS, otherwise the return value of C<posix_madvise>.	2164	ENOSYS, otherwise the return value of C<posix_madvise>.
1851		2165
1852	=item IO::AIO::mprotect $scalar, $offset, $len, $protect	2166	=item IO::AIO::mprotect $scalar, $offset, $len, $protect
…		…
1854	Simply calls the C<mprotect> function on the preferably AIO::mmap'ed	2168	Simply calls the C<mprotect> function on the preferably AIO::mmap'ed
1855	$scalar (see its manpage for details). The following protect	2169	$scalar (see its manpage for details). The following protect
1856	constants are available: C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_READ>,	2170	constants are available: C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_READ>,
1857	C<IO::AIO::PROT_WRITE>, C<IO::AIO::PROT_EXEC>.	2171	C<IO::AIO::PROT_WRITE>, C<IO::AIO::PROT_EXEC>.
1858		2172
		2173	If C<$offset> is negative, counts from the end. If C<$length> is negative,
		2174	the remaining length of the C<$scalar> is used. If possible, C<$length>
		2175	will be reduced to fit into the C<$scalar>.
		2176
1859	On systems that do not implement C<mprotect>, this function returns	2177	On systems that do not implement C<mprotect>, this function returns
1860	ENOSYS, otherwise the return value of C<mprotect>.	2178	ENOSYS, otherwise the return value of C<mprotect>.
1861		2179
1862	=item IO::AIO::mmap $scalar, $length, $prot, $flags, $fh[, $offset]	2180	=item IO::AIO::mmap $scalar, $length, $prot, $flags, $fh[, $offset]
1863		2181
1864	Memory-maps a file (or anonymous memory range) and attaches it to the	2182	Memory-maps a file (or anonymous memory range) and attaches it to the
1865	given C<$scalar>, which will act like a string scalar.	2183	given C<$scalar>, which will act like a string scalar. Returns true on
		2184	success, and false otherwise.
1866		2185
		2186	The scalar must exist, but its contents do not matter - this means you
		2187	cannot use a nonexistant array or hash element. When in doubt, C<undef>
		2188	the scalar first.
		2189
1867	The only operations allowed on the scalar are C<substr>/C<vec> that don't	2190	The only operations allowed on the mmapped scalar are C<substr>/C<vec>,
1868	change the string length, and most read-only operations such as copying it	2191	which don't change the string length, and most read-only operations such
1869	or searching it with regexes and so on.	2192	as copying it or searching it with regexes and so on.
1870		2193
1871	Anything else is unsafe and will, at best, result in memory leaks.	2194	Anything else is unsafe and will, at best, result in memory leaks.
1872		2195
1873	The memory map associated with the C<$scalar> is automatically removed	2196	The memory map associated with the C<$scalar> is automatically removed
1874	when the C<$scalar> is destroyed, or when the C<IO::AIO::mmap> or	2197	when the C<$scalar> is undef'd or destroyed, or when the C<IO::AIO::mmap>
1875	C<IO::AIO::munmap> functions are called.	2198	or C<IO::AIO::munmap> functions are called on it.
1876		2199
1877	This calls the C<mmap>(2) function internally. See your system's manual	2200	This calls the C<mmap>(2) function internally. See your system's manual
1878	page for details on the C<$length>, C<$prot> and C<$flags> parameters.	2201	page for details on the C<$length>, C<$prot> and C<$flags> parameters.
1879		2202
1880	The C<$length> must be larger than zero and smaller than the actual	2203	The C<$length> must be larger than zero and smaller than the actual
1881	filesize.	2204	filesize.
1882		2205
1883	C<$prot> is a combination of C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_EXEC>,	2206	C<$prot> is a combination of C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_EXEC>,
1884	C<IO::AIO::PROT_READ> and/or C<IO::AIO::PROT_WRITE>,	2207	C<IO::AIO::PROT_READ> and/or C<IO::AIO::PROT_WRITE>,
1885		2208
1886	C<$flags> can be a combination of C<IO::AIO::MAP_SHARED> or	2209	C<$flags> can be a combination of
1887	C<IO::AIO::MAP_PRIVATE>, or a number of system-specific flags (when	2210	C<IO::AIO::MAP_SHARED> or
1888	not available, the are defined as 0): C<IO::AIO::MAP_ANONYMOUS>	2211	C<IO::AIO::MAP_PRIVATE>,
		2212	or a number of system-specific flags (when not available, the are C<0>):
1889	(which is set to C<MAP_ANON> if your system only provides this	2213	C<IO::AIO::MAP_ANONYMOUS> (which is set to C<MAP_ANON> if your system only provides this constant),
1890	constant), C<IO::AIO::MAP_HUGETLB>, C<IO::AIO::MAP_LOCKED>,	2214	C<IO::AIO::MAP_LOCKED>,
1891	C<IO::AIO::MAP_NORESERVE>, C<IO::AIO::MAP_POPULATE> or	2215	C<IO::AIO::MAP_NORESERVE>,
		2216	C<IO::AIO::MAP_POPULATE>,
1892	C<IO::AIO::MAP_NONBLOCK>	2217	C<IO::AIO::MAP_NONBLOCK>,
		2218	C<IO::AIO::MAP_FIXED>,
		2219	C<IO::AIO::MAP_GROWSDOWN>,
		2220	C<IO::AIO::MAP_32BIT>,
		2221	C<IO::AIO::MAP_HUGETLB> or
		2222	C<IO::AIO::MAP_STACK>.
1893		2223
1894	If C<$fh> is C<undef>, then a file descriptor of C<-1> is passed.	2224	If C<$fh> is C<undef>, then a file descriptor of C<-1> is passed.
1895		2225
1896	C<$offset> is the offset from the start of the file - it generally must be	2226	C<$offset> is the offset from the start of the file - it generally must be
1897	a multiple of C<IO::AIO::PAGESIZE> and defaults to C<0>.	2227	a multiple of C<IO::AIO::PAGESIZE> and defaults to C<0>.
…		…
1922		2252
1923	Calls the C<munlockall> function.	2253	Calls the C<munlockall> function.
1924		2254
1925	On systems that do not implement C<munlockall>, this function returns	2255	On systems that do not implement C<munlockall>, this function returns
1926	ENOSYS, otherwise the return value of C<munlockall>.	2256	ENOSYS, otherwise the return value of C<munlockall>.
		2257
		2258	=item IO::AIO::splice $r_fh, $r_off, $w_fh, $w_off, $length, $flags
		2259
		2260	Calls the GNU/Linux C<splice(2)> syscall, if available. If C<$r_off> or
		2261	C<$w_off> are C<undef>, then C<NULL> is passed for these, otherwise they
		2262	should be the file offset.
		2263
		2264	C<$r_fh> and C<$w_fh> should not refer to the same file, as splice might
		2265	silently corrupt the data in this case.
		2266
		2267	The following symbol flag values are available: C<IO::AIO::SPLICE_F_MOVE>,
		2268	C<IO::AIO::SPLICE_F_NONBLOCK>, C<IO::AIO::SPLICE_F_MORE> and
		2269	C<IO::AIO::SPLICE_F_GIFT>.
		2270
		2271	See the C<splice(2)> manpage for details.
		2272
		2273	=item IO::AIO::tee $r_fh, $w_fh, $length, $flags
		2274
		2275	Calls the GNU/Linux C<tee(2)> syscall, see its manpage and the
		2276	description for C<IO::AIO::splice> above for details.
		2277
		2278	=item $actual_size = IO::AIO::pipesize $r_fh[, $new_size]
		2279
		2280	Attempts to query or change the pipe buffer size. Obviously works only
		2281	on pipes, and currently works only on GNU/Linux systems, and fails with
		2282	C<-1>/C<ENOSYS> everywhere else. If anybody knows how to influence pipe buffer
		2283	size on other systems, drop me a note.
		2284
		2285	=item ($rfh, $wfh) = IO::AIO::pipe2 [$flags]
		2286
		2287	This is a direct interface to the Linux L<pipe2(2)> system call. If
		2288	C<$flags> is missing or C<0>, then this should be the same as a call to
		2289	perl's built-in C<pipe> function and create a new pipe, and works on
		2290	systems that lack the pipe2 syscall. On win32, this case invokes C<_pipe
		2291	(..., 4096, O_BINARY)>.
		2292
		2293	If C<$flags> is non-zero, it tries to invoke the pipe2 system call with
		2294	the given flags (Linux 2.6.27, glibc 2.9).
		2295
		2296	On success, the read and write file handles are returned.
		2297
		2298	On error, nothing will be returned. If the pipe2 syscall is missing and
		2299	C<$flags> is non-zero, fails with C<ENOSYS>.
		2300
		2301	Please refer to L<pipe2(2)> for more info on the C<$flags>, but at the
		2302	time of this writing, C<IO::AIO::O_CLOEXEC>, C<IO::AIO::O_NONBLOCK> and
		2303	C<IO::AIO::O_DIRECT> (Linux 3.4, for packet-based pipes) were supported.
1927		2304
1928	=back	2305	=back
1929		2306
1930	=cut	2307	=cut
1931		2308

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Comparing IO-AIO/AIO.pm (file contents): Revision 1.220 by root, Sun Apr 1 17:46:02 2012 UTC vs. Revision 1.279 by root, Sat Jan 6 01:04:42 2018 UTC

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Comparing IO-AIO/AIO.pm (file contents):
Revision 1.220 by root, Sun Apr 1 17:46:02 2012 UTC vs.
Revision 1.279 by root, Sat Jan 6 01:04:42 2018 UTC