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

Comparing IO-AIO/AIO.pm (file contents):
Revision 1.229 by root, Wed Jul 25 16:32:30 2012 UTC vs.
Revision 1.284 by root, Fri Mar 23 01:14:08 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 = '4.15';	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 aio_fiemap	182	aio_pathsync aio_readahead aio_fiemap aio_allocate
180	aio_rename aio_link aio_move aio_copy aio_group	183	aio_rename aio_rename2 aio_link aio_move aio_copy aio_group
181	aio_nop aio_mknod aio_load aio_rmtree aio_mkdir aio_chown	184	aio_nop aio_mknod aio_load aio_rmtree aio_mkdir aio_chown
182	aio_chmod aio_utime aio_truncate	185	aio_chmod aio_utime aio_truncate
183	aio_msync aio_mtouch aio_mlock aio_mlockall	186	aio_msync aio_mtouch aio_mlock aio_mlockall
184	aio_statvfs	187	aio_statvfs
		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)
…		…
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)
226	aio_allocate $fh, $mode, $offset, $len, $callback->($status)	230	aio_allocate $fh, $mode, $offset, $len, $callback->($status)
		231	aio_fiemap $fh, $start, $length, $flags, $count, $cb->(\@extents)
227	aio_unlink $pathname, $callback->($status)	232	aio_unlink $pathname, $callback->($status)
228	aio_mknod $pathname, $mode, $dev, $callback->($status)	233	aio_mknod $pathname, $mode, $dev, $callback->($status)
229	aio_link $srcpath, $dstpath, $callback->($status)	234	aio_link $srcpath, $dstpath, $callback->($status)
230	aio_symlink $srcpath, $dstpath, $callback->($status)	235	aio_symlink $srcpath, $dstpath, $callback->($status)
231	aio_readlink $pathname, $callback->($link)	236	aio_readlink $pathname, $callback->($link)
232	aio_realpath $pathname, $callback->($link)	237	aio_realpath $pathname, $callback->($path)
233	aio_rename $srcpath, $dstpath, $callback->($status)	238	aio_rename $srcpath, $dstpath, $callback->($status)
		239	aio_rename2 $srcpath, $dstpath, $flags, $callback->($status)
234	aio_mkdir $pathname, $mode, $callback->($status)	240	aio_mkdir $pathname, $mode, $callback->($status)
235	aio_rmdir $pathname, $callback->($status)	241	aio_rmdir $pathname, $callback->($status)
236	aio_readdir $pathname, $callback->($entries)	242	aio_readdir $pathname, $callback->($entries)
237	aio_readdirx $pathname, $flags, $callback->($entries, $flags)	243	aio_readdirx $pathname, $flags, $callback->($entries, $flags)
238	IO::AIO::READDIR_DENTS IO::AIO::READDIR_DIRS_FIRST	244	IO::AIO::READDIR_DENTS IO::AIO::READDIR_DIRS_FIRST
…		…
240	aio_scandir $pathname, $maxreq, $callback->($dirs, $nondirs)	246	aio_scandir $pathname, $maxreq, $callback->($dirs, $nondirs)
241	aio_load $pathname, $data, $callback->($status)	247	aio_load $pathname, $data, $callback->($status)
242	aio_copy $srcpath, $dstpath, $callback->($status)	248	aio_copy $srcpath, $dstpath, $callback->($status)
243	aio_move $srcpath, $dstpath, $callback->($status)	249	aio_move $srcpath, $dstpath, $callback->($status)
244	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)
245	aio_sync $callback->($status)	253	aio_sync $callback->($status)
246	aio_syncfs $fh, $callback->($status)	254	aio_syncfs $fh, $callback->($status)
247	aio_fsync $fh, $callback->($status)	255	aio_fsync $fh, $callback->($status)
248	aio_fdatasync $fh, $callback->($status)	256	aio_fdatasync $fh, $callback->($status)
249	aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status)	257	aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status)
250	aio_pathsync $pathname, $callback->($status)	258	aio_pathsync $pathname, $callback->($status)
251	aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)	259	aio_msync $scalar, $offset = 0, $length = undef, flags = MS_SYNC, $callback->($status)
252	aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)	260	aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
253	aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status)	261	aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status)
254	aio_mlockall $flags, $callback->($status)	262	aio_mlockall $flags, $callback->($status)
255	aio_group $callback->(...)	263	aio_group $callback->(...)
256	aio_nop $callback->()	264	aio_nop $callback->()
…		…
270	IO::AIO::idle_timeout $seconds	278	IO::AIO::idle_timeout $seconds
271	IO::AIO::max_outstanding $maxreqs	279	IO::AIO::max_outstanding $maxreqs
272	IO::AIO::nreqs	280	IO::AIO::nreqs
273	IO::AIO::nready	281	IO::AIO::nready
274	IO::AIO::npending	282	IO::AIO::npending
		283	$nfd = IO::AIO::get_fdlimit [EXPERIMENTAL]
		284	IO::AIO::min_fdlimit $nfd [EXPERIMENTAL]
275		285
276	IO::AIO::sendfile $ofh, $ifh, $offset, $count	286	IO::AIO::sendfile $ofh, $ifh, $offset, $count
277	IO::AIO::fadvise $fh, $offset, $len, $advice	287	IO::AIO::fadvise $fh, $offset, $len, $advice
278	IO::AIO::mmap $scalar, $length, $prot, $flags[, $fh[, $offset]]	288	IO::AIO::mmap $scalar, $length, $prot, $flags[, $fh[, $offset]]
279	IO::AIO::munmap $scalar	289	IO::AIO::munmap $scalar
…		…
361		371
362		372
363	=item aio_open $pathname, $flags, $mode, $callback->($fh)	373	=item aio_open $pathname, $flags, $mode, $callback->($fh)
364		374
365	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
366	created filehandle for the file.	376	created filehandle for the file (or C<undef> in case of an error).
367		377
368	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,
369	for an explanation.	379	for an explanation.
370		380
371	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
…		…
394	following POSIX and non-POSIX constants are available (missing ones on	404	following POSIX and non-POSIX constants are available (missing ones on
395	your system are, as usual, C<0>):	405	your system are, as usual, C<0>):
396		406
397	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>,
398	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>,
399	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>.
400		410
401		411
402	=item aio_close $fh, $callback->($status)	412	=item aio_close $fh, $callback->($status)
403		413
404	Asynchronously close a file and call the callback with the result	414	Asynchronously close a file and call the callback with the result
…		…
439	=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)	449	=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
440		450
441	=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)	451	=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
442		452
443	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
444	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
445	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
446	error, just like the syscall).	456	error, just like the syscall).
447		457
448	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
449	offset plus the actual number of bytes read.	459	offset plus the actual number of bytes read.
450		460
…		…
508	As native sendfile syscalls (as practically any non-POSIX interface hacked	518	As native sendfile syscalls (as practically any non-POSIX interface hacked
509	together in a hurry to improve benchmark numbers) tend to be rather buggy	519	together in a hurry to improve benchmark numbers) tend to be rather buggy
510	on many systems, this implementation tries to work around some known bugs	520	on many systems, this implementation tries to work around some known bugs
511	in Linux and FreeBSD kernels (probably others, too), but that might fail,	521	in Linux and FreeBSD kernels (probably others, too), but that might fail,
512	so you really really should check the return value of C<aio_sendfile> -	522	so you really really should check the return value of C<aio_sendfile> -
513	fewre bytes than expected might have been transferred.	523	fewer bytes than expected might have been transferred.
514		524
515		525
516	=item aio_readahead $fh,$offset,$length, $callback->($retval)	526	=item aio_readahead $fh,$offset,$length, $callback->($retval)
517		527
518	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
…		…
522	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
523	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
524	(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
525	file. The current file offset of the file is left unchanged.	535	file. The current file offset of the file is left unchanged.
526		536
527	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
528	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.
529		539
530		540
531	=item aio_stat $fh_or_path, $callback->($status)	541	=item aio_stat $fh_or_path, $callback->($status)
532		542
533	=item aio_lstat $fh, $callback->($status)	543	=item aio_lstat $fh, $callback->($status)
…		…
602	namemax => 255,	612	namemax => 255,
603	frsize => 1024,	613	frsize => 1024,
604	fsid => 1810	614	fsid => 1810
605	}	615	}
606		616
607
608	=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status)	617	=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
609		618
610	Works like perl's C<utime> function (including the special case of $atime	619	Works like perl's C<utime> function (including the special case of $atime
611	and $mtime being undef). Fractional times are supported if the underlying	620	and $mtime being undef). Fractional times are supported if the underlying
612	syscalls support them.	621	syscalls support them.
…		…
641	Works like truncate(2) or ftruncate(2).	650	Works like truncate(2) or ftruncate(2).
642		651
643		652
644	=item aio_allocate $fh, $mode, $offset, $len, $callback->($status)	653	=item aio_allocate $fh, $mode, $offset, $len, $callback->($status)
645		654
646	Allocates or freed disk space according to the C<$mode> argument. See the	655	Allocates or frees disk space according to the C<$mode> argument. See the
647	linux C<fallocate> docuemntation for details.	656	linux C<fallocate> documentation for details.
648		657
649	C<$mode> can currently be C<0> or C<IO::AIO::FALLOC_FL_KEEP_SIZE>	658	C<$mode> is usually C<0> or C<IO::AIO::FALLOC_FL_KEEP_SIZE> to allocate
650	to allocate space, or C<IO::AIO::FALLOC_FL_PUNCH_HOLE \|	659	space, or C<IO::AIO::FALLOC_FL_PUNCH_HOLE \| IO::AIO::FALLOC_FL_KEEP_SIZE>,
651	IO::AIO::FALLOC_FL_KEEP_SIZE>, to deallocate a file range.	660	to deallocate a file range.
		661
		662	IO::AIO also supports C<FALLOC_FL_COLLAPSE_RANGE>, to remove a range
		663	(without leaving a hole), C<FALLOC_FL_ZERO_RANGE>, to zero a range,
		664	C<FALLOC_FL_INSERT_RANGE> to insert a range and C<FALLOC_FL_UNSHARE_RANGE>
		665	to unshare shared blocks (see your L<fallocate(2)> manpage).
652		666
653	The file system block size used by C<fallocate> is presumably the	667	The file system block size used by C<fallocate> is presumably the
654	C<f_bsize> returned by C<statvfs>.	668	C<f_bsize> returned by C<statvfs>, but different filesystems and filetypes
		669	can dictate other limitations.
655		670
656	If C<fallocate> isn't available or cannot be emulated (currently no	671	If C<fallocate> isn't available or cannot be emulated (currently no
657	emulation will be attempted), passes C<-1> and sets C<$!> to C<ENOSYS>.	672	emulation will be attempted), passes C<-1> and sets C<$!> to C<ENOSYS>.
658		673
659		674
…		…
701		716
702		717
703	=item aio_realpath $pathname, $callback->($path)	718	=item aio_realpath $pathname, $callback->($path)
704		719
705	Asynchronously make the path absolute and resolve any symlinks in	720	Asynchronously make the path absolute and resolve any symlinks in
706	C<$path>. The resulting path only consists of directories (Same as	721	C<$path>. The resulting path only consists of directories (same as
707	L<Cwd::realpath>).	722	L<Cwd::realpath>).
708		723
709	This request can be used to get the absolute path of the current working	724	This request can be used to get the absolute path of the current working
710	directory by passing it a path of F<.> (a single dot).	725	directory by passing it a path of F<.> (a single dot).
711		726
712		727
713	=item aio_rename $srcpath, $dstpath, $callback->($status)	728	=item aio_rename $srcpath, $dstpath, $callback->($status)
714		729
715	Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as	730	Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as
716	rename(2) and call the callback with the result code.	731	rename(2) and call the callback with the result code.
		732
		733	On systems that support the AIO::WD working directory abstraction
		734	natively, the case C<[$wd, "."]> as C<$srcpath> is specialcased - instead
		735	of failing, C<rename> is called on the absolute path of C<$wd>.
		736
		737
		738	=item aio_rename2 $srcpath, $dstpath, $flags, $callback->($status)
		739
		740	Basically a version of C<aio_rename> with an additional C<$flags>
		741	argument. Calling this with C<$flags=0> is the same as calling
		742	C<aio_rename>.
		743
		744	Non-zero flags are currently only supported on GNU/Linux systems that
		745	support renameat2. Other systems fail with C<ENOSYS> in this case.
		746
		747	The following constants are available (missing ones are, as usual C<0>),
		748	see renameat2(2) for details:
		749
		750	C<IO::AIO::RENAME_NOREPLACE>, C<IO::AIO::RENAME_EXCHANGE>
		751	and C<IO::AIO::RENAME_WHITEOUT>.
717		752
718		753
719	=item aio_mkdir $pathname, $mode, $callback->($status)	754	=item aio_mkdir $pathname, $mode, $callback->($status)
720		755
721	Asynchronously mkdir (create) a directory and call the callback with	756	Asynchronously mkdir (create) a directory and call the callback with
…		…
726	=item aio_rmdir $pathname, $callback->($status)	761	=item aio_rmdir $pathname, $callback->($status)
727		762
728	Asynchronously rmdir (delete) a directory and call the callback with the	763	Asynchronously rmdir (delete) a directory and call the callback with the
729	result code.	764	result code.
730		765
		766	On systems that support the AIO::WD working directory abstraction
		767	natively, the case C<[$wd, "."]> is specialcased - instead of failing,
		768	C<rmdir> is called on the absolute path of C<$wd>.
		769
731		770
732	=item aio_readdir $pathname, $callback->($entries)	771	=item aio_readdir $pathname, $callback->($entries)
733		772
734	Unlike the POSIX call of the same name, C<aio_readdir> reads an entire	773	Unlike the POSIX call of the same name, C<aio_readdir> reads an entire
735	directory (i.e. opendir + readdir + closedir). The entries will not be	774	directory (i.e. opendir + readdir + closedir). The entries will not be
…		…
750		789
751	=over 4	790	=over 4
752		791
753	=item IO::AIO::READDIR_DENTS	792	=item IO::AIO::READDIR_DENTS
754		793
755	When this flag is off, then the callback gets an arrayref consisting of	794	Normally the callback gets an arrayref consisting of names only (as
756	names only (as with C<aio_readdir>), otherwise it gets an arrayref with	795	with C<aio_readdir>). If this flag is set, then the callback gets an
757	C<[$name, $type, $inode]> arrayrefs, each describing a single directory	796	arrayref with C<[$name, $type, $inode]> arrayrefs, each describing a
758	entry in more detail.	797	single directory entry in more detail:
759		798
760	C<$name> is the name of the entry.	799	C<$name> is the name of the entry.
761		800
762	C<$type> is one of the C<IO::AIO::DT_xxx> constants:	801	C<$type> is one of the C<IO::AIO::DT_xxx> constants:
763		802
764	C<IO::AIO::DT_UNKNOWN>, C<IO::AIO::DT_FIFO>, C<IO::AIO::DT_CHR>, C<IO::AIO::DT_DIR>,	803	C<IO::AIO::DT_UNKNOWN>, C<IO::AIO::DT_FIFO>, C<IO::AIO::DT_CHR>, C<IO::AIO::DT_DIR>,
765	C<IO::AIO::DT_BLK>, C<IO::AIO::DT_REG>, C<IO::AIO::DT_LNK>, C<IO::AIO::DT_SOCK>,	804	C<IO::AIO::DT_BLK>, C<IO::AIO::DT_REG>, C<IO::AIO::DT_LNK>, C<IO::AIO::DT_SOCK>,
766	C<IO::AIO::DT_WHT>.	805	C<IO::AIO::DT_WHT>.
767		806
768	C<IO::AIO::DT_UNKNOWN> means just that: readdir does not know. If you need to	807	C<IO::AIO::DT_UNKNOWN> means just that: readdir does not know. If you need
769	know, you have to run stat yourself. Also, for speed reasons, the C<$type>	808	to know, you have to run stat yourself. Also, for speed/memory reasons,
770	scalars are read-only: you can not modify them.	809	the C<$type> scalars are read-only: you must not modify them.
771		810
772	C<$inode> is the inode number (which might not be exact on systems with 64	811	C<$inode> is the inode number (which might not be exact on systems with 64
773	bit inode numbers and 32 bit perls). This field has unspecified content on	812	bit inode numbers and 32 bit perls). This field has unspecified content on
774	systems that do not deliver the inode information.	813	systems that do not deliver the inode information.
775		814
…		…
786	short names are tried first.	825	short names are tried first.
787		826
788	=item IO::AIO::READDIR_STAT_ORDER	827	=item IO::AIO::READDIR_STAT_ORDER
789		828
790	When this flag is set, then the names will be returned in an order	829	When this flag is set, then the names will be returned in an order
791	suitable for stat()'ing each one. That is, when you plan to stat()	830	suitable for stat()'ing each one. That is, when you plan to stat() most or
792	all files in the given directory, then the returned order will likely	831	all files in the given directory, then the returned order will likely be
793	be fastest.	832	faster.
794		833
795	If both this flag and C<IO::AIO::READDIR_DIRS_FIRST> are specified, then	834	If both this flag and C<IO::AIO::READDIR_DIRS_FIRST> are specified,
796	the likely dirs come first, resulting in a less optimal stat order.	835	then the likely dirs come first, resulting in a less optimal stat order
		836	for stat'ing all entries, but likely a more optimal order for finding
		837	subdirectories.
797		838
798	=item IO::AIO::READDIR_FOUND_UNKNOWN	839	=item IO::AIO::READDIR_FOUND_UNKNOWN
799		840
800	This flag should not be set when calling C<aio_readdirx>. Instead, it	841	This flag should not be set when calling C<aio_readdirx>. Instead, it
801	is being set by C<aio_readdirx>, when any of the C<$type>'s found were	842	is being set by C<aio_readdirx>, when any of the C<$type>'s found were
…		…
803	C<$type>'s are known, which can be used to speed up some algorithms.	844	C<$type>'s are known, which can be used to speed up some algorithms.
804		845
805	=back	846	=back
806		847
807		848
		849	=item aio_slurp $pathname, $offset, $length, $data, $callback->($status)
		850
		851	Opens, reads and closes the given file. The data is put into C<$data>,
		852	which is resized as required.
		853
		854	If C<$offset> is negative, then it is counted from the end of the file.
		855
		856	If C<$length> is zero, then the remaining length of the file is
		857	used. Also, in this case, the same limitations to modifying C<$data> apply
		858	as when IO::AIO::mmap is used, i.e. it must only be modified in-place
		859	with C<substr>. If the size of the file is known, specifying a non-zero
		860	C<$length> results in a performance advantage.
		861
		862	This request is similar to the older C<aio_load> request, but since it is
		863	a single request, it might be more efficient to use.
		864
		865	Example: load F</etc/passwd> into C<$passwd>.
		866
		867	my $passwd;
		868	aio_slurp "/etc/passwd", 0, 0, $passwd, sub {
		869	$_[0] >= 0
		870	or die "/etc/passwd: $!\n";
		871
		872	printf "/etc/passwd is %d bytes long, and contains:\n", length $passwd;
		873	print $passwd;
		874	};
		875	IO::AIO::flush;
		876
		877
808	=item aio_load $pathname, $data, $callback->($status)	878	=item aio_load $pathname, $data, $callback->($status)
809		879
810	This is a composite request that tries to fully load the given file into	880	This is a composite request that tries to fully load the given file into
811	memory. Status is the same as with aio_read.	881	memory. Status is the same as with aio_read.
		882
		883	Using C<aio_slurp> might be more efficient, as it is a single request.
812		884
813	=cut	885	=cut
814		886
815	sub aio_load($$;$) {	887	sub aio_load($$;$) {
816	my ($path, undef, $cb) = @_;	888	my ($path, undef, $cb) = @_;
…		…
836	=item aio_copy $srcpath, $dstpath, $callback->($status)	908	=item aio_copy $srcpath, $dstpath, $callback->($status)
837		909
838	Try to copy the I<file> (directories not supported as either source or	910	Try to copy the I<file> (directories not supported as either source or
839	destination) from C<$srcpath> to C<$dstpath> and call the callback with	911	destination) from C<$srcpath> to C<$dstpath> and call the callback with
840	a status of C<0> (ok) or C<-1> (error, see C<$!>).	912	a status of C<0> (ok) or C<-1> (error, see C<$!>).
		913
		914	Existing destination files will be truncated.
841		915
842	This is a composite request that creates the destination file with	916	This is a composite request that creates the destination file with
843	mode 0200 and copies the contents of the source file into it using	917	mode 0200 and copies the contents of the source file into it using
844	C<aio_sendfile>, followed by restoring atime, mtime, access mode and	918	C<aio_sendfile>, followed by restoring atime, mtime, access mode and
845	uid/gid, in that order.	919	uid/gid, in that order.
…		…
955	Scans a directory (similar to C<aio_readdir>) but additionally tries to	1029	Scans a directory (similar to C<aio_readdir>) but additionally tries to
956	efficiently separate the entries of directory C<$path> into two sets of	1030	efficiently separate the entries of directory C<$path> into two sets of
957	names, directories you can recurse into (directories), and ones you cannot	1031	names, directories you can recurse into (directories), and ones you cannot
958	recurse into (everything else, including symlinks to directories).	1032	recurse into (everything else, including symlinks to directories).
959		1033
960	C<aio_scandir> is a composite request that creates of many sub requests_	1034	C<aio_scandir> is a composite request that generates many sub requests.
961	C<$maxreq> specifies the maximum number of outstanding aio requests that	1035	C<$maxreq> specifies the maximum number of outstanding aio requests that
962	this function generates. If it is C<< <= 0 >>, then a suitable default	1036	this function generates. If it is C<< <= 0 >>, then a suitable default
963	will be chosen (currently 4).	1037	will be chosen (currently 4).
964		1038
965	On error, the callback is called without arguments, otherwise it receives	1039	On error, the callback is called without arguments, otherwise it receives
…		…
1099	}	1173	}
1100		1174
1101	=item aio_rmtree $pathname, $callback->($status)	1175	=item aio_rmtree $pathname, $callback->($status)
1102		1176
1103	Delete a directory tree starting (and including) C<$path>, return the	1177	Delete a directory tree starting (and including) C<$path>, return the
1104	status of the final C<rmdir> only. This is a composite request that	1178	status of the final C<rmdir> only. This is a composite request that
1105	uses C<aio_scandir> to recurse into and rmdir directories, and unlink	1179	uses C<aio_scandir> to recurse into and rmdir directories, and unlink
1106	everything else.	1180	everything else.
1107		1181
1108	=cut	1182	=cut
1109		1183
…		…
1130	add $grp $dirgrp;	1204	add $grp $dirgrp;
1131	};	1205	};
1132		1206
1133	$grp	1207	$grp
1134	}	1208	}
		1209
		1210	=item aio_fcntl $fh, $cmd, $arg, $callback->($status)
		1211
		1212	=item aio_ioctl $fh, $request, $buf, $callback->($status)
		1213
		1214	These work just like the C<fcntl> and C<ioctl> built-in functions, except
		1215	they execute asynchronously and pass the return value to the callback.
		1216
		1217	Both calls can be used for a lot of things, some of which make more sense
		1218	to run asynchronously in their own thread, while some others make less
		1219	sense. For example, calls that block waiting for external events, such
		1220	as locking, will also lock down an I/O thread while it is waiting, which
		1221	can deadlock the whole I/O system. At the same time, there might be no
		1222	alternative to using a thread to wait.
		1223
		1224	So in general, you should only use these calls for things that do
		1225	(filesystem) I/O, not for things that wait for other events (network,
		1226	other processes), although if you are careful and know what you are doing,
		1227	you still can.
		1228
		1229	The following constants are available (missing ones are, as usual C<0>):
		1230
		1231	C<F_DUPFD_CLOEXEC>,
		1232
		1233	C<F_OFD_GETLK>, C<F_OFD_SETLK>, C<F_OFD_GETLKW>,
		1234
		1235	C<FIFREEZE>, C<FITHAW>, C<FITRIM>, C<FICLONE>, C<FICLONERANGE>, C<FIDEDUPERANGE>.
		1236
		1237	C<FS_IOC_GETFLAGS>, C<FS_IOC_SETFLAGS>, C<FS_IOC_GETVERSION>, C<FS_IOC_SETVERSION>,
		1238	C<FS_IOC_FIEMAP>.
		1239
		1240	C<FS_IOC_FSGETXATTR>, C<FS_IOC_FSSETXATTR>, C<FS_IOC_SET_ENCRYPTION_POLICY>,
		1241	C<FS_IOC_GET_ENCRYPTION_PWSALT>, C<FS_IOC_GET_ENCRYPTION_POLICY>, C<FS_KEY_DESCRIPTOR_SIZE>.
		1242
		1243	C<FS_SECRM_FL>, C<FS_UNRM_FL>, C<FS_COMPR_FL>, C<FS_SYNC_FL>, C<FS_IMMUTABLE_FL>,
		1244	C<FS_APPEND_FL>, C<FS_NODUMP_FL>, C<FS_NOATIME_FL>, C<FS_DIRTY_FL>,
		1245	C<FS_COMPRBLK_FL>, C<FS_NOCOMP_FL>, C<FS_ENCRYPT_FL>, C<FS_BTREE_FL>,
		1246	C<FS_INDEX_FL>, C<FS_JOURNAL_DATA_FL>, C<FS_NOTAIL_FL>, C<FS_DIRSYNC_FL>, C<FS_TOPDIR_FL>,
		1247	C<FS_FL_USER_MODIFIABLE>.
		1248
		1249	C<FS_XFLAG_REALTIME>, C<FS_XFLAG_PREALLOC>, C<FS_XFLAG_IMMUTABLE>, C<FS_XFLAG_APPEND>,
		1250	C<FS_XFLAG_SYNC>, C<FS_XFLAG_NOATIME>, C<FS_XFLAG_NODUMP>, C<FS_XFLAG_RTINHERIT>,
		1251	C<FS_XFLAG_PROJINHERIT>, C<FS_XFLAG_NOSYMLINKS>, C<FS_XFLAG_EXTSIZE>, C<FS_XFLAG_EXTSZINHERIT>,
		1252	C<FS_XFLAG_NODEFRAG>, C<FS_XFLAG_FILESTREAM>, C<FS_XFLAG_DAX>, C<FS_XFLAG_HASATTR>,
1135		1253
1136	=item aio_sync $callback->($status)	1254	=item aio_sync $callback->($status)
1137		1255
1138	Asynchronously call sync and call the callback when finished.	1256	Asynchronously call sync and call the callback when finished.
1139		1257
…		…
1208	};	1326	};
1209		1327
1210	$grp	1328	$grp
1211	}	1329	}
1212		1330
1213	=item aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)	1331	=item aio_msync $scalar, $offset = 0, $length = undef, flags = MS_SYNC, $callback->($status)
1214		1332
1215	This is a rather advanced IO::AIO call, which only works on mmap(2)ed	1333	This is a rather advanced IO::AIO call, which only works on mmap(2)ed
1216	scalars (see the C<IO::AIO::mmap> function, although it also works on data	1334	scalars (see the C<IO::AIO::mmap> function, although it also works on data
1217	scalars managed by the L<Sys::Mmap> or L<Mmap> modules, note that the	1335	scalars managed by the L<Sys::Mmap> or L<Mmap> modules, note that the
1218	scalar must only be modified in-place while an aio operation is pending on	1336	scalar must only be modified in-place while an aio operation is pending on
…		…
1220		1338
1221	It calls the C<msync> function of your OS, if available, with the memory	1339	It calls the C<msync> function of your OS, if available, with the memory
1222	area starting at C<$offset> in the string and ending C<$length> bytes	1340	area starting at C<$offset> in the string and ending C<$length> bytes
1223	later. If C<$length> is negative, counts from the end, and if C<$length>	1341	later. If C<$length> is negative, counts from the end, and if C<$length>
1224	is C<undef>, then it goes till the end of the string. The flags can be	1342	is C<undef>, then it goes till the end of the string. The flags can be
1225	a combination of C<IO::AIO::MS_ASYNC>, C<IO::AIO::MS_INVALIDATE> and	1343	either C<IO::AIO::MS_ASYNC> or C<IO::AIO::MS_SYNC>, plus an optional
1226	C<IO::AIO::MS_SYNC>.	1344	C<IO::AIO::MS_INVALIDATE>.
1227		1345
1228	=item aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)	1346	=item aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
1229		1347
1230	This is a rather advanced IO::AIO call, which works best on mmap(2)ed	1348	This is a rather advanced IO::AIO call, which works best on mmap(2)ed
1231	scalars.	1349	scalars.
1232		1350
1233	It touches (reads or writes) all memory pages in the specified	1351	It touches (reads or writes) all memory pages in the specified
1234	range inside the scalar. All caveats and parameters are the same	1352	range inside the scalar. All caveats and parameters are the same
1235	as for C<aio_msync>, above, except for flags, which must be either	1353	as for C<aio_msync>, above, except for flags, which must be either
1236	C<0> (which reads all pages and ensures they are instantiated) or	1354	C<0> (which reads all pages and ensures they are instantiated) or
1237	C<IO::AIO::MT_MODIFY>, which modifies the memory page s(by reading and	1355	C<IO::AIO::MT_MODIFY>, which modifies the memory pages (by reading and
1238	writing an octet from it, which dirties the page).	1356	writing an octet from it, which dirties the page).
1239		1357
1240	=item aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status)	1358	=item aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status)
1241		1359
1242	This is a rather advanced IO::AIO call, which works best on mmap(2)ed	1360	This is a rather advanced IO::AIO call, which works best on mmap(2)ed
…		…
1276		1394
1277	aio_mlockall IO::AIO::MCL_FUTURE;	1395	aio_mlockall IO::AIO::MCL_FUTURE;
1278		1396
1279	=item aio_fiemap $fh, $start, $length, $flags, $count, $cb->(\@extents)	1397	=item aio_fiemap $fh, $start, $length, $flags, $count, $cb->(\@extents)
1280		1398
1281	Queries the extents of the given file (by calling the Linux FIEMAP ioctl,	1399	Queries the extents of the given file (by calling the Linux C<FIEMAP>
1282	see L<http://cvs.schmorp.de/IO-AIO/doc/fiemap.txt> for details). If the	1400	ioctl, see L<http://cvs.schmorp.de/IO-AIO/doc/fiemap.txt> for details). If
1283	C<ioctl> is not available on your OS, then this rquiest will fail with	1401	the ioctl is not available on your OS, then this request will fail with
1284	C<ENOSYS>.	1402	C<ENOSYS>.
1285		1403
1286	C<$start> is the starting offset to query extents for, C<$length> is the	1404	C<$start> is the starting offset to query extents for, C<$length> is the
1287	size of the range to query - if it is C<undef>, then the whole file will	1405	size of the range to query - if it is C<undef>, then the whole file will
1288	be queried.	1406	be queried.
…		…
1291	C<IO::AIO::FIEMAP_FLAG_XATTR> - C<IO::AIO::FIEMAP_FLAGS_COMPAT> is also	1409	C<IO::AIO::FIEMAP_FLAG_XATTR> - C<IO::AIO::FIEMAP_FLAGS_COMPAT> is also
1292	exported), and is normally C<0> or C<IO::AIO::FIEMAP_FLAG_SYNC> to query	1410	exported), and is normally C<0> or C<IO::AIO::FIEMAP_FLAG_SYNC> to query
1293	the data portion.	1411	the data portion.
1294		1412
1295	C<$count> is the maximum number of extent records to return. If it is	1413	C<$count> is the maximum number of extent records to return. If it is
1296	C<undef>, then IO::AIO queries all extents of the file. As a very special	1414	C<undef>, then IO::AIO queries all extents of the range. As a very special
1297	case, if it is C<0>, then the callback receives the number of extents	1415	case, if it is C<0>, then the callback receives the number of extents
1298	instead of the extents themselves.	1416	instead of the extents themselves (which is unreliable, see below).
1299		1417
1300	If an error occurs, the callback receives no arguments. The special	1418	If an error occurs, the callback receives no arguments. The special
1301	C<errno> value C<IO::AIO::EBADR> is available to test for flag errors.	1419	C<errno> value C<IO::AIO::EBADR> is available to test for flag errors.
1302		1420
1303	Otherwise, the callback receives an array reference with extent	1421	Otherwise, the callback receives an array reference with extent
…		…
1305	following members:	1423	following members:
1306		1424
1307	[$logical, $physical, $length, $flags]	1425	[$logical, $physical, $length, $flags]
1308		1426
1309	Flags is any combination of the following flag values (typically either C<0>	1427	Flags is any combination of the following flag values (typically either C<0>
1310	or C<IO::AIO::FIEMAP_EXTENT_LAST>):	1428	or C<IO::AIO::FIEMAP_EXTENT_LAST> (1)):
1311		1429
1312	C<IO::AIO::FIEMAP_EXTENT_LAST>, C<IO::AIO::FIEMAP_EXTENT_UNKNOWN>,	1430	C<IO::AIO::FIEMAP_EXTENT_LAST>, C<IO::AIO::FIEMAP_EXTENT_UNKNOWN>,
1313	C<IO::AIO::FIEMAP_EXTENT_DELALLOC>, C<IO::AIO::FIEMAP_EXTENT_ENCODED>,	1431	C<IO::AIO::FIEMAP_EXTENT_DELALLOC>, C<IO::AIO::FIEMAP_EXTENT_ENCODED>,
1314	C<IO::AIO::FIEMAP_EXTENT_DATA_ENCRYPTED>, C<IO::AIO::FIEMAP_EXTENT_NOT_ALIGNED>,	1432	C<IO::AIO::FIEMAP_EXTENT_DATA_ENCRYPTED>, C<IO::AIO::FIEMAP_EXTENT_NOT_ALIGNED>,
1315	C<IO::AIO::FIEMAP_EXTENT_DATA_INLINE>, C<IO::AIO::FIEMAP_EXTENT_DATA_TAIL>,	1433	C<IO::AIO::FIEMAP_EXTENT_DATA_INLINE>, C<IO::AIO::FIEMAP_EXTENT_DATA_TAIL>,
1316	C<IO::AIO::FIEMAP_EXTENT_UNWRITTEN>, C<IO::AIO::FIEMAP_EXTENT_MERGED> or	1434	C<IO::AIO::FIEMAP_EXTENT_UNWRITTEN>, C<IO::AIO::FIEMAP_EXTENT_MERGED> or
1317	C<IO::AIO::FIEMAP_EXTENT_SHARED>.	1435	C<IO::AIO::FIEMAP_EXTENT_SHARED>.
1318		1436
		1437	At the time of this writing (Linux 3.2), this request is unreliable unless
		1438	C<$count> is C<undef>, as the kernel has all sorts of bugs preventing
		1439	it to return all extents of a range for files with a large number of
		1440	extents. The code (only) works around all these issues if C<$count> is
		1441	C<undef>.
		1442
1319	=item aio_group $callback->(...)	1443	=item aio_group $callback->(...)
1320		1444
1321	This is a very special aio request: Instead of doing something, it is a	1445	This is a very special aio request: Instead of doing something, it is a
1322	container for other aio requests, which is useful if you want to bundle	1446	container for other aio requests, which is useful if you want to bundle
1323	many requests into a single, composite, request with a definite callback	1447	many requests into a single, composite, request with a definite callback
…		…
1406	aio_stat [$etcdir, "passwd"], sub {	1530	aio_stat [$etcdir, "passwd"], sub {
1407	# yay	1531	# yay
1408	};	1532	};
1409	};	1533	};
1410		1534
1411	That C<aio_wd> is a request and not a normal function shows that creating	1535	The fact that C<aio_wd> is a request and not a normal function shows that
1412	an IO::AIO::WD object is itself a potentially blocking operation, which is	1536	creating an IO::AIO::WD object is itself a potentially blocking operation,
1413	why it is done asynchronously.	1537	which is why it is done asynchronously.
1414		1538
1415	To stat the directory obtained with C<aio_wd> above, one could write	1539	To stat the directory obtained with C<aio_wd> above, one could write
1416	either of the following three request calls:	1540	either of the following three request calls:
1417		1541
1418	aio_lstat "/etc" , sub { ... # pathname as normal string	1542	aio_lstat "/etc" , sub { ... # pathname as normal string
…		…
1435	There are some caveats: when directories get renamed (or deleted), the	1559	There are some caveats: when directories get renamed (or deleted), the
1436	pathname string doesn't change, so will point to the new directory (or	1560	pathname string doesn't change, so will point to the new directory (or
1437	nowhere at all), while the directory fd, if available on the system,	1561	nowhere at all), while the directory fd, if available on the system,
1438	will still point to the original directory. Most functions accepting a	1562	will still point to the original directory. Most functions accepting a
1439	pathname will use the directory fd on newer systems, and the string on	1563	pathname will use the directory fd on newer systems, and the string on
1440	older systems. Some functions (such as realpath) will always rely on the	1564	older systems. Some functions (such as C<aio_realpath>) will always rely on
1441	string form of the pathname.	1565	the string form of the pathname.
1442		1566
1443	So this fucntionality is mainly useful to get some protection against	1567	So this functionality is mainly useful to get some protection against
1444	C<chdir>, to easily get an absolute path out of a relative path for future	1568	C<chdir>, to easily get an absolute path out of a relative path for future
1445	reference, and to speed up doing many operations in the same directory	1569	reference, and to speed up doing many operations in the same directory
1446	(e.g. when stat'ing all files in a directory).	1570	(e.g. when stat'ing all files in a directory).
1447		1571
1448	The following functions implement this working directory abstraction:	1572	The following functions implement this working directory abstraction:
…		…
1461	passing C<undef> as working directory component of a pathname fails the	1585	passing C<undef> as working directory component of a pathname fails the
1462	request with C<ENOENT>, there is often no need for error checking in the	1586	request with C<ENOENT>, there is often no need for error checking in the
1463	C<aio_wd> callback, as future requests using the value will fail in the	1587	C<aio_wd> callback, as future requests using the value will fail in the
1464	expected way.	1588	expected way.
1465		1589
1466	If this call isn't available because your OS lacks it or it couldn't be
1467	detected, it will be emulated by calling C<fsync> instead.
1468
1469	=item IO::AIO::CWD	1590	=item IO::AIO::CWD
1470		1591
1471	This is a compiletime constant (object) that represents the process	1592	This is a compiletime constant (object) that represents the process
1472	current working directory.	1593	current working directory.
1473		1594
1474	Specifying this object as working directory object for a pathname is as	1595	Specifying this object as working directory object for a pathname is as if
1475	if the pathname would be specified directly, without a directory object,	1596	the pathname would be specified directly, without a directory object. For
1476	e.g., these calls are functionally identical:	1597	example, these calls are functionally identical:
1477		1598
1478	aio_stat "somefile", sub { ... };	1599	aio_stat "somefile", sub { ... };
1479	aio_stat [IO::AIO::CWD, "somefile"], sub { ... };	1600	aio_stat [IO::AIO::CWD, "somefile"], sub { ... };
1480		1601
1481	=back	1602	=back
1482		1603
		1604	To recover the path associated with an IO::AIO::WD object, you can use
		1605	C<aio_realpath>:
		1606
		1607	aio_realpath $wd, sub {
		1608	warn "path is $_[0]\n";
		1609	};
		1610
		1611	Currently, C<aio_statvfs> always, and C<aio_rename> and C<aio_rmdir>
		1612	sometimes, fall back to using an absolue path.
1483		1613
1484	=head2 IO::AIO::REQ CLASS	1614	=head2 IO::AIO::REQ CLASS
1485		1615
1486	All non-aggregate C<aio_*> functions return an object of this class when	1616	All non-aggregate C<aio_*> functions return an object of this class when
1487	called in non-void context.	1617	called in non-void context.
…		…
1665		1795
1666	See C<poll_cb> for an example.	1796	See C<poll_cb> for an example.
1667		1797
1668	=item IO::AIO::poll_cb	1798	=item IO::AIO::poll_cb
1669		1799
1670	Process some outstanding events on the result pipe. You have to call	1800	Process some requests that have reached the result phase (i.e. they have
		1801	been executed but the results are not yet reported). You have to call
		1802	this "regularly" to finish outstanding requests.
		1803
1671	this regularly. Returns C<0> if all events could be processed (or there	1804	Returns C<0> if all events could be processed (or there were no
1672	were no events to process), or C<-1> if it returned earlier for whatever	1805	events to process), or C<-1> if it returned earlier for whatever
1673	reason. Returns immediately when no events are outstanding. The amount of	1806	reason. Returns immediately when no events are outstanding. The amount
1674	events processed depends on the settings of C<IO::AIO::max_poll_req> and	1807	of events processed depends on the settings of C<IO::AIO::max_poll_req>,
1675	C<IO::AIO::max_poll_time>.	1808	C<IO::AIO::max_poll_time> and C<IO::AIO::max_outstanding>.
1676		1809
1677	If not all requests were processed for whatever reason, the filehandle	1810	If not all requests were processed for whatever reason, the poll file
1678	will still be ready when C<poll_cb> returns, so normally you don't have to	1811	descriptor will still be ready when C<poll_cb> returns, so normally you
1679	do anything special to have it called later.	1812	don't have to do anything special to have it called later.
1680		1813
1681	Apart from calling C<IO::AIO::poll_cb> when the event filehandle becomes	1814	Apart from calling C<IO::AIO::poll_cb> when the event filehandle becomes
1682	ready, it can be beneficial to call this function from loops which submit	1815	ready, it can be beneficial to call this function from loops which submit
1683	a lot of requests, to make sure the results get processed when they become	1816	a lot of requests, to make sure the results get processed when they become
1684	available and not just when the loop is finished and the event loop takes	1817	available and not just when the loop is finished and the event loop takes
…		…
1693	poll => 'r', async => 1,	1826	poll => 'r', async => 1,
1694	cb => \&IO::AIO::poll_cb);	1827	cb => \&IO::AIO::poll_cb);
1695		1828
1696	=item IO::AIO::poll_wait	1829	=item IO::AIO::poll_wait
1697		1830
1698	If there are any outstanding requests and none of them in the result	1831	Wait until either at least one request is in the result phase or no
1699	phase, wait till the result filehandle becomes ready for reading (simply	1832	requests are outstanding anymore.
1700	does a C<select> on the filehandle. This is useful if you want to	1833
1701	synchronously wait for some requests to finish).	1834	This is useful if you want to synchronously wait for some requests to
		1835	become ready, without actually handling them.
1702		1836
1703	See C<nreqs> for an example.	1837	See C<nreqs> for an example.
1704		1838
1705	=item IO::AIO::poll	1839	=item IO::AIO::poll
1706		1840
…		…
1827		1961
1828	This is a very bad function to use in interactive programs because it	1962	This is a very bad function to use in interactive programs because it
1829	blocks, and a bad way to reduce concurrency because it is inexact: Better	1963	blocks, and a bad way to reduce concurrency because it is inexact: Better
1830	use an C<aio_group> together with a feed callback.	1964	use an C<aio_group> together with a feed callback.
1831		1965
1832	It's main use is in scripts without an event loop - when you want to stat	1966	Its main use is in scripts without an event loop - when you want to stat
1833	a lot of files, you can write somehting like this:	1967	a lot of files, you can write something like this:
1834		1968
1835	IO::AIO::max_outstanding 32;	1969	IO::AIO::max_outstanding 32;
1836		1970
1837	for my $path (...) {	1971	for my $path (...) {
1838	aio_stat $path , ...;	1972	aio_stat $path , ...;
…		…
1877		2011
1878	=back	2012	=back
1879		2013
1880	=head3 MISCELLANEOUS FUNCTIONS	2014	=head3 MISCELLANEOUS FUNCTIONS
1881		2015
1882	IO::AIO implements some functions that might be useful, but are not	2016	IO::AIO implements some functions that are useful when you want to use
1883	asynchronous.	2017	some "Advanced I/O" function not available to in Perl, without going the
		2018	"Asynchronous I/O" route. Many of these have an asynchronous C<aio_*>
		2019	counterpart.
1884		2020
1885	=over 4	2021	=over 4
		2022
		2023	=item $numfd = IO::AIO::get_fdlimit
		2024
		2025	This function is I<EXPERIMENTAL> and subject to change.
		2026
		2027	Tries to find the current file descriptor limit and returns it, or
		2028	C<undef> and sets C<$!> in case of an error. The limit is one larger than
		2029	the highest valid file descriptor number.
		2030
		2031	=item IO::AIO::min_fdlimit [$numfd]
		2032
		2033	This function is I<EXPERIMENTAL> and subject to change.
		2034
		2035	Try to increase the current file descriptor limit(s) to at least C<$numfd>
		2036	by changing the soft or hard file descriptor resource limit. If C<$numfd>
		2037	is missing, it will try to set a very high limit, although this is not
		2038	recommended when you know the actual minimum that you require.
		2039
		2040	If the limit cannot be raised enough, the function makes a best-effort
		2041	attempt to increase the limit as much as possible, using various
		2042	tricks, while still failing. You can query the resulting limit using
		2043	C<IO::AIO::get_fdlimit>.
		2044
		2045	If an error occurs, returns C<undef> and sets C<$!>, otherwise returns
		2046	true.
1886		2047
1887	=item IO::AIO::sendfile $ofh, $ifh, $offset, $count	2048	=item IO::AIO::sendfile $ofh, $ifh, $offset, $count
1888		2049
1889	Calls the C<eio_sendfile_sync> function, which is like C<aio_sendfile>,	2050	Calls the C<eio_sendfile_sync> function, which is like C<aio_sendfile>,
1890	but is blocking (this makes most sense if you know the input data is	2051	but is blocking (this makes most sense if you know the input data is
…		…
1907	=item IO::AIO::madvise $scalar, $offset, $len, $advice	2068	=item IO::AIO::madvise $scalar, $offset, $len, $advice
1908		2069
1909	Simply calls the C<posix_madvise> function (see its	2070	Simply calls the C<posix_madvise> function (see its
1910	manpage for details). The following advice constants are	2071	manpage for details). The following advice constants are
1911	available: C<IO::AIO::MADV_NORMAL>, C<IO::AIO::MADV_SEQUENTIAL>,	2072	available: C<IO::AIO::MADV_NORMAL>, C<IO::AIO::MADV_SEQUENTIAL>,
1912	C<IO::AIO::MADV_RANDOM>, C<IO::AIO::MADV_WILLNEED>, C<IO::AIO::MADV_DONTNEED>.	2073	C<IO::AIO::MADV_RANDOM>, C<IO::AIO::MADV_WILLNEED>,
		2074	C<IO::AIO::MADV_DONTNEED>.
		2075
		2076	If C<$offset> is negative, counts from the end. If C<$length> is negative,
		2077	the remaining length of the C<$scalar> is used. If possible, C<$length>
		2078	will be reduced to fit into the C<$scalar>.
1913		2079
1914	On systems that do not implement C<posix_madvise>, this function returns	2080	On systems that do not implement C<posix_madvise>, this function returns
1915	ENOSYS, otherwise the return value of C<posix_madvise>.	2081	ENOSYS, otherwise the return value of C<posix_madvise>.
1916		2082
1917	=item IO::AIO::mprotect $scalar, $offset, $len, $protect	2083	=item IO::AIO::mprotect $scalar, $offset, $len, $protect
…		…
1919	Simply calls the C<mprotect> function on the preferably AIO::mmap'ed	2085	Simply calls the C<mprotect> function on the preferably AIO::mmap'ed
1920	$scalar (see its manpage for details). The following protect	2086	$scalar (see its manpage for details). The following protect
1921	constants are available: C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_READ>,	2087	constants are available: C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_READ>,
1922	C<IO::AIO::PROT_WRITE>, C<IO::AIO::PROT_EXEC>.	2088	C<IO::AIO::PROT_WRITE>, C<IO::AIO::PROT_EXEC>.
1923		2089
		2090	If C<$offset> is negative, counts from the end. If C<$length> is negative,
		2091	the remaining length of the C<$scalar> is used. If possible, C<$length>
		2092	will be reduced to fit into the C<$scalar>.
		2093
1924	On systems that do not implement C<mprotect>, this function returns	2094	On systems that do not implement C<mprotect>, this function returns
1925	ENOSYS, otherwise the return value of C<mprotect>.	2095	ENOSYS, otherwise the return value of C<mprotect>.
1926		2096
1927	=item IO::AIO::mmap $scalar, $length, $prot, $flags, $fh[, $offset]	2097	=item IO::AIO::mmap $scalar, $length, $prot, $flags, $fh[, $offset]
1928		2098
1929	Memory-maps a file (or anonymous memory range) and attaches it to the	2099	Memory-maps a file (or anonymous memory range) and attaches it to the
1930	given C<$scalar>, which will act like a string scalar. Returns true on	2100	given C<$scalar>, which will act like a string scalar. Returns true on
1931	success, and false otherwise.	2101	success, and false otherwise.
1932		2102
		2103	The scalar must exist, but its contents do not matter - this means you
		2104	cannot use a nonexistant array or hash element. When in doubt, C<undef>
		2105	the scalar first.
		2106
1933	The only operations allowed on the scalar are C<substr>/C<vec> that don't	2107	The only operations allowed on the mmapped scalar are C<substr>/C<vec>,
1934	change the string length, and most read-only operations such as copying it	2108	which don't change the string length, and most read-only operations such
1935	or searching it with regexes and so on.	2109	as copying it or searching it with regexes and so on.
1936		2110
1937	Anything else is unsafe and will, at best, result in memory leaks.	2111	Anything else is unsafe and will, at best, result in memory leaks.
1938		2112
1939	The memory map associated with the C<$scalar> is automatically removed	2113	The memory map associated with the C<$scalar> is automatically removed
1940	when the C<$scalar> is destroyed, or when the C<IO::AIO::mmap> or	2114	when the C<$scalar> is undef'd or destroyed, or when the C<IO::AIO::mmap>
1941	C<IO::AIO::munmap> functions are called.	2115	or C<IO::AIO::munmap> functions are called on it.
1942		2116
1943	This calls the C<mmap>(2) function internally. See your system's manual	2117	This calls the C<mmap>(2) function internally. See your system's manual
1944	page for details on the C<$length>, C<$prot> and C<$flags> parameters.	2118	page for details on the C<$length>, C<$prot> and C<$flags> parameters.
1945		2119
1946	The C<$length> must be larger than zero and smaller than the actual	2120	The C<$length> must be larger than zero and smaller than the actual
1947	filesize.	2121	filesize.
1948		2122
1949	C<$prot> is a combination of C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_EXEC>,	2123	C<$prot> is a combination of C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_EXEC>,
1950	C<IO::AIO::PROT_READ> and/or C<IO::AIO::PROT_WRITE>,	2124	C<IO::AIO::PROT_READ> and/or C<IO::AIO::PROT_WRITE>,
1951		2125
1952	C<$flags> can be a combination of C<IO::AIO::MAP_SHARED> or	2126	C<$flags> can be a combination of
1953	C<IO::AIO::MAP_PRIVATE>, or a number of system-specific flags (when	2127	C<IO::AIO::MAP_SHARED> or
1954	not available, the are defined as 0): C<IO::AIO::MAP_ANONYMOUS>	2128	C<IO::AIO::MAP_PRIVATE>,
		2129	or a number of system-specific flags (when not available, the are C<0>):
1955	(which is set to C<MAP_ANON> if your system only provides this	2130	C<IO::AIO::MAP_ANONYMOUS> (which is set to C<MAP_ANON> if your system only provides this constant),
1956	constant), C<IO::AIO::MAP_HUGETLB>, C<IO::AIO::MAP_LOCKED>,	2131	C<IO::AIO::MAP_LOCKED>,
1957	C<IO::AIO::MAP_NORESERVE>, C<IO::AIO::MAP_POPULATE> or	2132	C<IO::AIO::MAP_NORESERVE>,
		2133	C<IO::AIO::MAP_POPULATE>,
1958	C<IO::AIO::MAP_NONBLOCK>	2134	C<IO::AIO::MAP_NONBLOCK>,
		2135	C<IO::AIO::MAP_FIXED>,
		2136	C<IO::AIO::MAP_GROWSDOWN>,
		2137	C<IO::AIO::MAP_32BIT>,
		2138	C<IO::AIO::MAP_HUGETLB> or
		2139	C<IO::AIO::MAP_STACK>.
1959		2140
1960	If C<$fh> is C<undef>, then a file descriptor of C<-1> is passed.	2141	If C<$fh> is C<undef>, then a file descriptor of C<-1> is passed.
1961		2142
1962	C<$offset> is the offset from the start of the file - it generally must be	2143	C<$offset> is the offset from the start of the file - it generally must be
1963	a multiple of C<IO::AIO::PAGESIZE> and defaults to C<0>.	2144	a multiple of C<IO::AIO::PAGESIZE> and defaults to C<0>.
…		…
2006		2187
2007	See the C<splice(2)> manpage for details.	2188	See the C<splice(2)> manpage for details.
2008		2189
2009	=item IO::AIO::tee $r_fh, $w_fh, $length, $flags	2190	=item IO::AIO::tee $r_fh, $w_fh, $length, $flags
2010		2191
2011	Calls the GNU/Linux C<tee(2)> syscall, see it's manpage and the	2192	Calls the GNU/Linux C<tee(2)> syscall, see its manpage and the
2012	description for C<IO::AIO::splice> above for details.	2193	description for C<IO::AIO::splice> above for details.
		2194
		2195	=item $actual_size = IO::AIO::pipesize $r_fh[, $new_size]
		2196
		2197	Attempts to query or change the pipe buffer size. Obviously works only
		2198	on pipes, and currently works only on GNU/Linux systems, and fails with
		2199	C<-1>/C<ENOSYS> everywhere else. If anybody knows how to influence pipe buffer
		2200	size on other systems, drop me a note.
		2201
		2202	=item ($rfh, $wfh) = IO::AIO::pipe2 [$flags]
		2203
		2204	This is a direct interface to the Linux L<pipe2(2)> system call. If
		2205	C<$flags> is missing or C<0>, then this should be the same as a call to
		2206	perl's built-in C<pipe> function and create a new pipe, and works on
		2207	systems that lack the pipe2 syscall. On win32, this case invokes C<_pipe
		2208	(..., 4096, O_BINARY)>.
		2209
		2210	If C<$flags> is non-zero, it tries to invoke the pipe2 system call with
		2211	the given flags (Linux 2.6.27, glibc 2.9).
		2212
		2213	On success, the read and write file handles are returned.
		2214
		2215	On error, nothing will be returned. If the pipe2 syscall is missing and
		2216	C<$flags> is non-zero, fails with C<ENOSYS>.
		2217
		2218	Please refer to L<pipe2(2)> for more info on the C<$flags>, but at the
		2219	time of this writing, C<IO::AIO::O_CLOEXEC>, C<IO::AIO::O_NONBLOCK> and
		2220	C<IO::AIO::O_DIRECT> (Linux 3.4, for packet-based pipes) were supported.
		2221
		2222	Example: create a pipe race-free w.r.t. threads and fork:
		2223
		2224	my ($rfh, $wfh) = IO::AIO::pipe2 IO::AIO::O_CLOEXEC
		2225	or die "pipe2: $!\n";
		2226
		2227	=item $fh = IO::AIO::eventfd [$initval, [$flags]]
		2228
		2229	This is a direct interface to the Linux L<eventfd(2)> system call. The
		2230	(unhelpful) defaults for C<$initval> and C<$flags> are C<0> for both.
		2231
		2232	On success, the new eventfd filehandle is returned, otherwise returns
		2233	C<undef>. If the eventfd syscall is missing, fails with C<ENOSYS>.
		2234
		2235	Please refer to L<eventfd(2)> for more info on this call.
		2236
		2237	The following symbol flag values are available: C<IO::AIO::EFD_CLOEXEC>,
		2238	C<IO::AIO::EFD_NONBLOCK> and C<IO::AIO::EFD_SEMAPHORE> (Linux 2.6.30).
		2239
		2240	Example: create a new eventfd filehandle:
		2241
		2242	$fh = IO::AIO::eventfd 0, IO::AIO::O_CLOEXEC
		2243	or die "eventfd: $!\n";
		2244
		2245	=item $fh = IO::AIO::timerfd_create $clockid[, $flags]
		2246
		2247	This is a direct interface to the Linux L<timerfd_create(2)> system call. The
		2248	(unhelpful) default for C<$flags> is C<0>.
		2249
		2250	On success, the new timerfd filehandle is returned, otherwise returns
		2251	C<undef>. If the eventfd syscall is missing, fails with C<ENOSYS>.
		2252
		2253	Please refer to L<timerfd_create(2)> for more info on this call.
		2254
		2255	The following C<$clockid> values are
		2256	available: C<IO::AIO::CLOCK_REALTIME>, C<IO::AIO::CLOCK_MONOTONIC>
		2257	C<IO::AIO::CLOCK_CLOCK_BOOTTIME> (Linux 3.15)
		2258	C<IO::AIO::CLOCK_CLOCK_REALTIME_ALARM> (Linux 3.11) and
		2259	C<IO::AIO::CLOCK_CLOCK_BOOTTIME_ALARM> (Linux 3.11).
		2260
		2261	The following C<$flags> values are available (Linux
		2262	2.6.27): C<IO::AIO::TFD_NONBLOCK> and C<IO::AIO::TFD_CLOEXEC>.
		2263
		2264	Example: create a new timerfd and set it to one-second repeated alarms,
		2265	then wait for two alarms:
		2266
		2267	my $fh = IO::AIO::timerfd_create IO::AIO::CLOCK_BOOTTIME, IO::AIO::TFD_CLOEXEC
		2268	or die "timerfd_create: $!\n";
		2269
		2270	defined IO::AIO::timerfd_settime $fh, 0, 1, 1
		2271	or die "timerfd_settime: $!\n";
		2272
		2273	for (1..2) {
		2274	8 == sysread $fh, my $buf, 8
		2275	or die "timerfd read failure\n";
		2276
		2277	printf "number of expirations (likely 1): %d\n",
		2278	unpack "Q", $buf;
		2279	}
		2280
		2281	=item ($cur_interval, $cur_value) = IO::AIO::timerfd_settime $fh, $flags, $new_interval, $nbw_value
		2282
		2283	This is a direct interface to the Linux L<timerfd_settime(2)> system
		2284	call. Please refer to its manpage for more info on this call.
		2285
		2286	The new itimerspec is specified using two (possibly fractional) second
		2287	values, C<$new_interval> and C<$new_value>).
		2288
		2289	On success, the current interval and value are returned (as per
		2290	C<timerfd_gettime>). On failure, the empty list is returned.
		2291
		2292	The following C<$flags> values are
		2293	available: C<IO::AIO::TFD_TIMER_ABSTIME> and
		2294	C<IO::AIO::TFD_TIMER_CANCEL_ON_SET>.
		2295
		2296	See C<IO::AIO::timerfd_create> for a full example.
		2297
		2298	=item ($cur_interval, $cur_value) = IO::AIO::timerfd_gettime $fh
		2299
		2300	This is a direct interface to the Linux L<timerfd_gettime(2)> system
		2301	call. Please refer to its manpage for more info on this call.
		2302
		2303	On success, returns the current values of interval and value for the given
		2304	timerfd (as potentially fractional second values). On failure, the empty
		2305	list is returned.
2013		2306
2014	=back	2307	=back
2015		2308
2016	=cut	2309	=cut
2017		2310
…		…
2083	the process will result in undefined behaviour. Calling it at any time	2376	the process will result in undefined behaviour. Calling it at any time
2084	will also result in any undefined (by POSIX) behaviour.	2377	will also result in any undefined (by POSIX) behaviour.
2085		2378
2086	=back	2379	=back
2087		2380
		2381	=head2 LINUX-SPECIFIC CALLS
		2382
		2383	When a call is documented as "linux-specific" then this means it
		2384	originated on GNU/Linux. C<IO::AIO> will usually try to autodetect the
		2385	availability and compatibility of such calls regardless of the platform
		2386	it is compiled on, so platforms such as FreeBSD which often implement
		2387	these calls will work. When in doubt, call them and see if they fail wth
		2388	C<ENOSYS>.
		2389
2088	=head2 MEMORY USAGE	2390	=head2 MEMORY USAGE
2089		2391
2090	Per-request usage:	2392	Per-request usage:
2091		2393
2092	Each aio request uses - depending on your architecture - around 100-200	2394	Each aio request uses - depending on your architecture - around 100-200
…		…
2104	temporary buffers, and each thread requires a stack and other data	2406	temporary buffers, and each thread requires a stack and other data
2105	structures (usually around 16k-128k, depending on the OS).	2407	structures (usually around 16k-128k, depending on the OS).
2106		2408
2107	=head1 KNOWN BUGS	2409	=head1 KNOWN BUGS
2108		2410
2109	Known bugs will be fixed in the next release.	2411	Known bugs will be fixed in the next release :)
		2412
		2413	=head1 KNOWN ISSUES
		2414
		2415	Calls that try to "import" foreign memory areas (such as C<IO::AIO::mmap>
		2416	or C<IO::AIO::aio_slurp>) do not work with generic lvalues, such as
		2417	non-created hash slots or other scalars I didn't think of. It's best to
		2418	avoid such and either use scalar variables or making sure that the scalar
		2419	exists (e.g. by storing C<undef>) and isn't "funny" (e.g. tied).
		2420
		2421	I am not sure anything can be done about this, so this is considered a
		2422	known issue, rather than a bug.
2110		2423
2111	=head1 SEE ALSO	2424	=head1 SEE ALSO
2112		2425
2113	L<AnyEvent::AIO> for easy integration into event loops, L<Coro::AIO> for a	2426	L<AnyEvent::AIO> for easy integration into event loops, L<Coro::AIO> for a
2114	more natural syntax.	2427	more natural syntax.

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Comparing IO-AIO/AIO.pm (file contents): Revision 1.229 by root, Wed Jul 25 16:32:30 2012 UTC vs. Revision 1.284 by root, Fri Mar 23 01:14:08 2018 UTC

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Comparing IO-AIO/AIO.pm (file contents):
Revision 1.229 by root, Wed Jul 25 16:32:30 2012 UTC vs.
Revision 1.284 by root, Fri Mar 23 01:14:08 2018 UTC