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Revision 1.105 by root, Sun Mar 25 00:20:27 2007 UTC vs.
Revision 1.186 by root, Thu Dec 30 07:19:31 2010 UTC

…		…
4		4
5	=head1 SYNOPSIS	5	=head1 SYNOPSIS
6		6
7	use IO::AIO;	7	use IO::AIO;
8		8
9	aio_open "/etc/passwd", O_RDONLY, 0, sub {	9	aio_open "/etc/passwd", IO::AIO::O_RDONLY, 0, sub {
10	my $fh = shift	10	my $fh = shift
11	or die "/etc/passwd: $!";	11	or die "/etc/passwd: $!";
12	...	12	...
13	};	13	};
14		14
…		…
26	$req->cancel; # cancel request if still in queue	26	$req->cancel; # cancel request if still in queue
27		27
28	my $grp = aio_group sub { print "all stats done\n" };	28	my $grp = aio_group sub { print "all stats done\n" };
29	add $grp aio_stat "..." for ...;	29	add $grp aio_stat "..." for ...;
30		30
31	# AnyEvent integration
32	open my $fh, "<&=" . IO::AIO::poll_fileno or die "$!";
33	my $w = AnyEvent->io (fh => $fh, poll => 'r', cb => sub { IO::AIO::poll_cb });
34
35	# Event integration
36	Event->io (fd => IO::AIO::poll_fileno,
37	poll => 'r',
38	cb => \&IO::AIO::poll_cb);
39
40	# Glib/Gtk2 integration
41	add_watch Glib::IO IO::AIO::poll_fileno,
42	in => sub { IO::AIO::poll_cb; 1 };
43
44	# Tk integration
45	Tk::Event::IO->fileevent (IO::AIO::poll_fileno, "",
46	readable => \&IO::AIO::poll_cb);
47
48	# Danga::Socket integration
49	Danga::Socket->AddOtherFds (IO::AIO::poll_fileno =>
50	\&IO::AIO::poll_cb);
51
52	=head1 DESCRIPTION	31	=head1 DESCRIPTION
53		32
54	This module implements asynchronous I/O using whatever means your	33	This module implements asynchronous I/O using whatever means your
55	operating system supports.	34	operating system supports. It is implemented as an interface to C<libeio>
		35	(L<http://software.schmorp.de/pkg/libeio.html>).
56		36
57	Asynchronous means that operations that can normally block your program	37	Asynchronous means that operations that can normally block your program
58	(e.g. reading from disk) will be done asynchronously: the operation	38	(e.g. reading from disk) will be done asynchronously: the operation
59	will still block, but you can do something else in the meantime. This	39	will still block, but you can do something else in the meantime. This
60	is extremely useful for programs that need to stay interactive even	40	is extremely useful for programs that need to stay interactive even
…		…
62	etc.), but can also be used to easily do operations in parallel that are	42	etc.), but can also be used to easily do operations in parallel that are
63	normally done sequentially, e.g. stat'ing many files, which is much faster	43	normally done sequentially, e.g. stat'ing many files, which is much faster
64	on a RAID volume or over NFS when you do a number of stat operations	44	on a RAID volume or over NFS when you do a number of stat operations
65	concurrently.	45	concurrently.
66		46
67	While most of this works on all types of file descriptors (for example	47	While most of this works on all types of file descriptors (for
68	sockets), using these functions on file descriptors that support	48	example sockets), using these functions on file descriptors that
69	nonblocking operation (again, sockets, pipes etc.) is very inefficient or	49	support nonblocking operation (again, sockets, pipes etc.) is
70	might not work (aio_read fails on sockets/pipes/fifos). Use an event loop	50	very inefficient. Use an event loop for that (such as the L<EV>
71	for that (such as the L<Event|Event> module): IO::AIO will naturally fit	51	module): IO::AIO will naturally fit into such an event loop itself.
72	into such an event loop itself.
73		52
74	In this version, a number of threads are started that execute your	53	In this version, a number of threads are started that execute your
75	requests and signal their completion. You don't need thread support	54	requests and signal their completion. You don't need thread support
76	in perl, and the threads created by this module will not be visible	55	in perl, and the threads created by this module will not be visible
77	to perl. In the future, this module might make use of the native aio	56	to perl. In the future, this module might make use of the native aio
…		…
79	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
80	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
81	aio_write, so the remaining functionality would have to be implemented	60	aio_write, so the remaining functionality would have to be implemented
82	using threads anyway.	61	using threads anyway.
83		62
84	Although the module will work with in the presence of other (Perl-)	63	Although the module will work in the presence of other (Perl-) threads,
85	threads, it is currently not reentrant in any way, so use appropriate	64	it is currently not reentrant in any way, so use appropriate locking
86	locking yourself, always call C<poll_cb> from within the same thread, or	65	yourself, always call C<poll_cb> from within the same thread, or never
87	never call C<poll_cb> (or other C<aio_> functions) recursively.	66	call C<poll_cb> (or other C<aio_> functions) recursively.
88		67
89	=head2 EXAMPLE	68	=head2 EXAMPLE
90		69
91	This is a simple example that uses the Event module and loads	70	This is a simple example that uses the EV module and loads
92	F</etc/passwd> asynchronously:	71	F</etc/passwd> asynchronously:
93		72
94	use Fcntl;	73	use Fcntl;
95	use Event;	74	use EV;
96	use IO::AIO;	75	use IO::AIO;
97		76
98	# register the IO::AIO callback with Event	77	# register the IO::AIO callback with EV
99	Event->io (fd => IO::AIO::poll_fileno,	78	my $aio_w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb;
100	poll => 'r',
101	cb => \&IO::AIO::poll_cb);
102		79
103	# queue the request to open /etc/passwd	80	# queue the request to open /etc/passwd
104	aio_open "/etc/passwd", O_RDONLY, 0, sub {	81	aio_open "/etc/passwd", IO::AIO::O_RDONLY, 0, sub {
105	my $fh = shift	82	my $fh = shift
106	or die "error while opening: $!";	83	or die "error while opening: $!";
107		84
108	# stat'ing filehandles is generally non-blocking	85	# stat'ing filehandles is generally non-blocking
109	my $size = -s $fh;	86	my $size = -s $fh;
…		…
118		95
119	# file contents now in $contents	96	# file contents now in $contents
120	print $contents;	97	print $contents;
121		98
122	# exit event loop and program	99	# exit event loop and program
123	Event::unloop;	100	EV::unloop;
124	};	101	};
125	};	102	};
126		103
127	# possibly queue up other requests, or open GUI windows,	104	# possibly queue up other requests, or open GUI windows,
128	# check for sockets etc. etc.	105	# check for sockets etc. etc.
129		106
130	# process events as long as there are some:	107	# process events as long as there are some:
131	Event::loop;	108	EV::loop;
132		109
133	=head1 REQUEST ANATOMY AND LIFETIME	110	=head1 REQUEST ANATOMY AND LIFETIME
134		111
135	Every C<aio_*> function creates a request. which is a C data structure not	112	Every C<aio_*> function creates a request. which is a C data structure not
136	directly visible to Perl.	113	directly visible to Perl.
…		…
184		161
185	=cut	162	=cut
186		163
187	package IO::AIO;	164	package IO::AIO;
188		165
189	no warnings;	166	use Carp ();
190	use strict 'vars';	167
		168	use common::sense;
191		169
192	use base 'Exporter';	170	use base 'Exporter';
193		171
194	BEGIN {	172	BEGIN {
195	our $VERSION = '2.33';	173	our $VERSION = '3.71';
196		174
197	our @AIO_REQ = qw(aio_sendfile aio_read aio_write aio_open aio_close aio_stat	175	our @AIO_REQ = qw(aio_sendfile aio_read aio_write aio_open aio_close
198	aio_lstat aio_unlink aio_rmdir aio_readdir aio_scandir aio_symlink	176	aio_stat aio_lstat aio_unlink aio_rmdir aio_readdir aio_readdirx
199	aio_readlink aio_fsync aio_fdatasync aio_readahead aio_rename aio_link	177	aio_scandir aio_symlink aio_readlink aio_sync aio_fsync
		178	aio_fdatasync aio_sync_file_range aio_pathsync aio_readahead
		179	aio_rename aio_link aio_move aio_copy aio_group
200	aio_move aio_copy aio_group aio_nop aio_mknod aio_load aio_rmtree aio_mkdir);	180	aio_nop aio_mknod aio_load aio_rmtree aio_mkdir aio_chown
		181	aio_chmod aio_utime aio_truncate
		182	aio_msync aio_mtouch aio_mlock aio_mlockall
		183	aio_statvfs);
		184
201	our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice aio_block));	185	our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice));
202	our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush	186	our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush
203	min_parallel max_parallel max_idle	187	min_parallel max_parallel max_idle
204	nreqs nready npending nthreads	188	nreqs nready npending nthreads
205	max_poll_time max_poll_reqs);	189	max_poll_time max_poll_reqs
		190	sendfile fadvise madvise
		191	mmap munmap munlock munlockall);
		192
		193	push @AIO_REQ, qw(aio_busy); # not exported
206		194
207	@IO::AIO::GRP::ISA = 'IO::AIO::REQ';	195	@IO::AIO::GRP::ISA = 'IO::AIO::REQ';
208		196
209	require XSLoader;	197	require XSLoader;
210	XSLoader::load ("IO::AIO", $VERSION);	198	XSLoader::load ("IO::AIO", $VERSION);
211	}	199	}
212		200
213	=head1 FUNCTIONS	201	=head1 FUNCTIONS
		202
		203	=head2 QUICK OVERVIEW
		204
		205	This section simply lists the prototypes of the most important functions
		206	for quick reference. See the following sections for function-by-function
		207	documentation.
		208
		209	aio_open $pathname, $flags, $mode, $callback->($fh)
		210	aio_close $fh, $callback->($status)
		211	aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
		212	aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
		213	aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval)
		214	aio_readahead $fh,$offset,$length, $callback->($retval)
		215	aio_stat $fh_or_path, $callback->($status)
		216	aio_lstat $fh, $callback->($status)
		217	aio_statvfs $fh_or_path, $callback->($statvfs)
		218	aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
		219	aio_chown $fh_or_path, $uid, $gid, $callback->($status)
		220	aio_truncate $fh_or_path, $offset, $callback->($status)
		221	aio_chmod $fh_or_path, $mode, $callback->($status)
		222	aio_unlink $pathname, $callback->($status)
		223	aio_mknod $path, $mode, $dev, $callback->($status)
		224	aio_link $srcpath, $dstpath, $callback->($status)
		225	aio_symlink $srcpath, $dstpath, $callback->($status)
		226	aio_readlink $path, $callback->($link)
		227	aio_rename $srcpath, $dstpath, $callback->($status)
		228	aio_mkdir $pathname, $mode, $callback->($status)
		229	aio_rmdir $pathname, $callback->($status)
		230	aio_readdir $pathname, $callback->($entries)
		231	aio_readdirx $pathname, $flags, $callback->($entries, $flags)
		232	IO::AIO::READDIR_DENTS IO::AIO::READDIR_DIRS_FIRST
		233	IO::AIO::READDIR_STAT_ORDER IO::AIO::READDIR_FOUND_UNKNOWN
		234	aio_load $path, $data, $callback->($status)
		235	aio_copy $srcpath, $dstpath, $callback->($status)
		236	aio_move $srcpath, $dstpath, $callback->($status)
		237	aio_scandir $path, $maxreq, $callback->($dirs, $nondirs)
		238	aio_rmtree $path, $callback->($status)
		239	aio_sync $callback->($status)
		240	aio_fsync $fh, $callback->($status)
		241	aio_fdatasync $fh, $callback->($status)
		242	aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status)
		243	aio_pathsync $path, $callback->($status)
		244	aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
		245	aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
		246	aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status)
		247	aio_mlockall $flags, $callback->($status)
		248	aio_group $callback->(...)
		249	aio_nop $callback->()
		250
		251	$prev_pri = aioreq_pri [$pri]
		252	aioreq_nice $pri_adjust
		253
		254	IO::AIO::poll_wait
		255	IO::AIO::poll_cb
		256	IO::AIO::poll
		257	IO::AIO::flush
		258	IO::AIO::max_poll_reqs $nreqs
		259	IO::AIO::max_poll_time $seconds
		260	IO::AIO::min_parallel $nthreads
		261	IO::AIO::max_parallel $nthreads
		262	IO::AIO::max_idle $nthreads
		263	IO::AIO::max_outstanding $maxreqs
		264	IO::AIO::nreqs
		265	IO::AIO::nready
		266	IO::AIO::npending
		267
		268	IO::AIO::sendfile $ofh, $ifh, $offset, $count
		269	IO::AIO::fadvise $fh, $offset, $len, $advice
		270	IO::AIO::madvise $scalar, $offset, $length, $advice
		271	IO::AIO::mprotect $scalar, $offset, $length, $protect
		272	IO::AIO::munlock $scalar, $offset = 0, $length = undef
		273	IO::AIO::munlockall
214		274
215	=head2 AIO REQUEST FUNCTIONS	275	=head2 AIO REQUEST FUNCTIONS
216		276
217	All the C<aio_*> calls are more or less thin wrappers around the syscall	277	All the C<aio_*> calls are more or less thin wrappers around the syscall
218	with the same name (sans C<aio_>). The arguments are similar or identical,	278	with the same name (sans C<aio_>). The arguments are similar or identical,
219	and they all accept an additional (and optional) C<$callback> argument	279	and they all accept an additional (and optional) C<$callback> argument
220	which must be a code reference. This code reference will get called with	280	which must be a code reference. This code reference will get called with
221	the syscall return code (e.g. most syscalls return C<-1> on error, unlike	281	the syscall return code (e.g. most syscalls return C<-1> on error, unlike
222	perl, which usually delivers "false") as it's sole argument when the given	282	perl, which usually delivers "false") as its sole argument after the given
223	syscall has been executed asynchronously.	283	syscall has been executed asynchronously.
224		284
225	All functions expecting a filehandle keep a copy of the filehandle	285	All functions expecting a filehandle keep a copy of the filehandle
226	internally until the request has finished.	286	internally until the request has finished.
227		287
…		…
241	your pathnames to the locale (or other) encoding in effect in the user	301	your pathnames to the locale (or other) encoding in effect in the user
242	environment, d) use Glib::filename_from_unicode on unicode filenames or e)	302	environment, d) use Glib::filename_from_unicode on unicode filenames or e)
243	use something else to ensure your scalar has the correct contents.	303	use something else to ensure your scalar has the correct contents.
244		304
245	This works, btw. independent of the internal UTF-8 bit, which IO::AIO	305	This works, btw. independent of the internal UTF-8 bit, which IO::AIO
246	handles correctly wether it is set or not.	306	handles correctly whether it is set or not.
247		307
248	=over 4	308	=over 4
249		309
250	=item $prev_pri = aioreq_pri [$pri]	310	=item $prev_pri = aioreq_pri [$pri]
251		311
…		…
271	aio_read $_[0], ..., sub {	331	aio_read $_[0], ..., sub {
272	...	332	...
273	};	333	};
274	};	334	};
275		335
		336
276	=item aioreq_nice $pri_adjust	337	=item aioreq_nice $pri_adjust
277		338
278	Similar to C<aioreq_pri>, but subtracts the given value from the current	339	Similar to C<aioreq_pri>, but subtracts the given value from the current
279	priority, so the effect is cumulative.	340	priority, so the effect is cumulative.
		341
280		342
281	=item aio_open $pathname, $flags, $mode, $callback->($fh)	343	=item aio_open $pathname, $flags, $mode, $callback->($fh)
282		344
283	Asynchronously open or create a file and call the callback with a newly	345	Asynchronously open or create a file and call the callback with a newly
284	created filehandle for the file.	346	created filehandle for the file.
…		…
296	by the umask in effect then the request is being executed, so better never	358	by the umask in effect then the request is being executed, so better never
297	change the umask.	359	change the umask.
298		360
299	Example:	361	Example:
300		362
301	aio_open "/etc/passwd", O_RDONLY, 0, sub {	363	aio_open "/etc/passwd", IO::AIO::O_RDONLY, 0, sub {
302	if ($_[0]) {	364	if ($_[0]) {
303	print "open successful, fh is $_[0]\n";	365	print "open successful, fh is $_[0]\n";
304	...	366	...
305	} else {	367	} else {
306	die "open failed: $!\n";	368	die "open failed: $!\n";
307	}	369	}
308	};	370	};
309		371
		372
310	=item aio_close $fh, $callback->($status)	373	=item aio_close $fh, $callback->($status)
311		374
312	Asynchronously close a file and call the callback with the result	375	Asynchronously close a file and call the callback with the result
313	code. I<WARNING:> although accepted, you should not pass in a perl	376	code.
314	filehandle here, as perl will likely close the file descriptor another
315	time when the filehandle is destroyed. Normally, you can safely call perls
316	C<close> or just let filehandles go out of scope.
317		377
318	This is supposed to be a bug in the API, so that might change. It's	378	Unfortunately, you can't do this to perl. Perl I<insists> very strongly on
319	therefore best to avoid this function.	379	closing the file descriptor associated with the filehandle itself.
		380
		381	Therefore, C<aio_close> will not close the filehandle - instead it will
		382	use dup2 to overwrite the file descriptor with the write-end of a pipe
		383	(the pipe fd will be created on demand and will be cached).
		384
		385	Or in other words: the file descriptor will be closed, but it will not be
		386	free for reuse until the perl filehandle is closed.
		387
		388	=cut
320		389
321	=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)	390	=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
322		391
323	=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)	392	=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
324		393
325	Reads or writes C<length> bytes from the specified C<fh> and C<offset>	394	Reads or writes C<$length> bytes from or to the specified C<$fh> and
326	into the scalar given by C<data> and offset C<dataoffset> and calls the	395	C<$offset> into the scalar given by C<$data> and offset C<$dataoffset>
327	callback without the actual number of bytes read (or -1 on error, just	396	and calls the callback without the actual number of bytes read (or -1 on
328	like the syscall).	397	error, just like the syscall).
		398
		399	C<aio_read> will, like C<sysread>, shrink or grow the C<$data> scalar to
		400	offset plus the actual number of bytes read.
		401
		402	If C<$offset> is undefined, then the current file descriptor offset will
		403	be used (and updated), otherwise the file descriptor offset will not be
		404	changed by these calls.
		405
		406	If C<$length> is undefined in C<aio_write>, use the remaining length of
		407	C<$data>.
		408
		409	If C<$dataoffset> is less than zero, it will be counted from the end of
		410	C<$data>.
329		411
330	The C<$data> scalar I<MUST NOT> be modified in any way while the request	412	The C<$data> scalar I<MUST NOT> be modified in any way while the request
331	is outstanding. Modifying it can result in segfaults or WW3 (if the	413	is outstanding. Modifying it can result in segfaults or World War III (if
332	necessary/optional hardware is installed).	414	the necessary/optional hardware is installed).
333		415
334	Example: Read 15 bytes at offset 7 into scalar C<$buffer>, starting at	416	Example: Read 15 bytes at offset 7 into scalar C<$buffer>, starting at
335	offset C<0> within the scalar:	417	offset C<0> within the scalar:
336		418
337	aio_read $fh, 7, 15, $buffer, 0, sub {	419	aio_read $fh, 7, 15, $buffer, 0, sub {
338	$_[0] > 0 or die "read error: $!";	420	$_[0] > 0 or die "read error: $!";
339	print "read $_[0] bytes: <$buffer>\n";	421	print "read $_[0] bytes: <$buffer>\n";
340	};	422	};
		423
341		424
342	=item aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval)	425	=item aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval)
343		426
344	Tries to copy C<$length> bytes from C<$in_fh> to C<$out_fh>. It starts	427	Tries to copy C<$length> bytes from C<$in_fh> to C<$out_fh>. It starts
345	reading at byte offset C<$in_offset>, and starts writing at the current	428	reading at byte offset C<$in_offset>, and starts writing at the current
346	file offset of C<$out_fh>. Because of that, it is not safe to issue more	429	file offset of C<$out_fh>. Because of that, it is not safe to issue more
347	than one C<aio_sendfile> per C<$out_fh>, as they will interfere with each	430	than one C<aio_sendfile> per C<$out_fh>, as they will interfere with each
348	other.	431	other.
349		432
		433	Please note that C<aio_sendfile> can read more bytes from C<$in_fh> than
		434	are written, and there is no way to find out how many bytes have been read
		435	from C<aio_sendfile> alone, as C<aio_sendfile> only provides the number of
		436	bytes written to C<$out_fh>. Only if the result value equals C<$length>
		437	one can assume that C<$length> bytes have been read.
		438
		439	Unlike with other C<aio_> functions, it makes a lot of sense to use
		440	C<aio_sendfile> on non-blocking sockets, as long as one end (typically
		441	the C<$in_fh>) is a file - the file I/O will then be asynchronous, while
		442	the socket I/O will be non-blocking. Note, however, that you can run into
		443	a trap where C<aio_sendfile> reads some data with readahead, then fails
		444	to write all data, and when the socket is ready the next time, the data
		445	in the cache is already lost, forcing C<aio_sendfile> to again hit the
		446	disk. Explicit C<aio_read> + C<aio_write> let's you control resource usage
		447	much better.
		448
350	This call tries to make use of a native C<sendfile> syscall to provide	449	This call tries to make use of a native C<sendfile> syscall to provide
351	zero-copy operation. For this to work, C<$out_fh> should refer to a	450	zero-copy operation. For this to work, C<$out_fh> should refer to a
352	socket, and C<$in_fh> should refer to mmap'able file.	451	socket, and C<$in_fh> should refer to an mmap'able file.
353		452
354	If the native sendfile call fails or is not implemented, it will be	453	If a native sendfile cannot be found or it fails with C<ENOSYS>,
		454	C<ENOTSUP>, C<EOPNOTSUPP>, C<EAFNOSUPPORT>, C<EPROTOTYPE> or C<ENOTSOCK>,
355	emulated, so you can call C<aio_sendfile> on any type of filehandle	455	it will be emulated, so you can call C<aio_sendfile> on any type of
356	regardless of the limitations of the operating system.	456	filehandle regardless of the limitations of the operating system.
357		457
358	Please note, however, that C<aio_sendfile> can read more bytes from
359	C<$in_fh> than are written, and there is no way to find out how many
360	bytes have been read from C<aio_sendfile> alone, as C<aio_sendfile> only
361	provides the number of bytes written to C<$out_fh>. Only if the result
362	value equals C<$length> one can assume that C<$length> bytes have been
363	read.
364		458
365	=item aio_readahead $fh,$offset,$length, $callback->($retval)	459	=item aio_readahead $fh,$offset,$length, $callback->($retval)
366		460
367	C<aio_readahead> populates the page cache with data from a file so that	461	C<aio_readahead> populates the page cache with data from a file so that
368	subsequent reads from that file will not block on disk I/O. The C<$offset>	462	subsequent reads from that file will not block on disk I/O. The C<$offset>
…		…
374	file. The current file offset of the file is left unchanged.	468	file. The current file offset of the file is left unchanged.
375		469
376	If that syscall doesn't exist (likely if your OS isn't Linux) it will be	470	If that syscall doesn't exist (likely if your OS isn't Linux) it will be
377	emulated by simply reading the data, which would have a similar effect.	471	emulated by simply reading the data, which would have a similar effect.
378		472
		473
379	=item aio_stat $fh_or_path, $callback->($status)	474	=item aio_stat $fh_or_path, $callback->($status)
380		475
381	=item aio_lstat $fh, $callback->($status)	476	=item aio_lstat $fh, $callback->($status)
382		477
383	Works like perl's C<stat> or C<lstat> in void context. The callback will	478	Works like perl's C<stat> or C<lstat> in void context. The callback will
…		…
396	aio_stat "/etc/passwd", sub {	491	aio_stat "/etc/passwd", sub {
397	$_[0] and die "stat failed: $!";	492	$_[0] and die "stat failed: $!";
398	print "size is ", -s _, "\n";	493	print "size is ", -s _, "\n";
399	};	494	};
400		495
		496
		497	=item aio_statvfs $fh_or_path, $callback->($statvfs)
		498
		499	Works like the POSIX C<statvfs> or C<fstatvfs> syscalls, depending on
		500	whether a file handle or path was passed.
		501
		502	On success, the callback is passed a hash reference with the following
		503	members: C<bsize>, C<frsize>, C<blocks>, C<bfree>, C<bavail>, C<files>,
		504	C<ffree>, C<favail>, C<fsid>, C<flag> and C<namemax>. On failure, C<undef>
		505	is passed.
		506
		507	The following POSIX IO::AIO::ST_* constants are defined: C<ST_RDONLY> and
		508	C<ST_NOSUID>.
		509
		510	The following non-POSIX IO::AIO::ST_* flag masks are defined to
		511	their correct value when available, or to C<0> on systems that do
		512	not support them: C<ST_NODEV>, C<ST_NOEXEC>, C<ST_SYNCHRONOUS>,
		513	C<ST_MANDLOCK>, C<ST_WRITE>, C<ST_APPEND>, C<ST_IMMUTABLE>, C<ST_NOATIME>,
		514	C<ST_NODIRATIME> and C<ST_RELATIME>.
		515
		516	Example: stat C</wd> and dump out the data if successful.
		517
		518	aio_statvfs "/wd", sub {
		519	my $f = $_[0]
		520	or die "statvfs: $!";
		521
		522	use Data::Dumper;
		523	say Dumper $f;
		524	};
		525
		526	# result:
		527	{
		528	bsize => 1024,
		529	bfree => 4333064312,
		530	blocks => 10253828096,
		531	files => 2050765568,
		532	flag => 4096,
		533	favail => 2042092649,
		534	bavail => 4333064312,
		535	ffree => 2042092649,
		536	namemax => 255,
		537	frsize => 1024,
		538	fsid => 1810
		539	}
		540
		541
		542	=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
		543
		544	Works like perl's C<utime> function (including the special case of $atime
		545	and $mtime being undef). Fractional times are supported if the underlying
		546	syscalls support them.
		547
		548	When called with a pathname, uses utimes(2) if available, otherwise
		549	utime(2). If called on a file descriptor, uses futimes(2) if available,
		550	otherwise returns ENOSYS, so this is not portable.
		551
		552	Examples:
		553
		554	# set atime and mtime to current time (basically touch(1)):
		555	aio_utime "path", undef, undef;
		556	# set atime to current time and mtime to beginning of the epoch:
		557	aio_utime "path", time, undef; # undef==0
		558
		559
		560	=item aio_chown $fh_or_path, $uid, $gid, $callback->($status)
		561
		562	Works like perl's C<chown> function, except that C<undef> for either $uid
		563	or $gid is being interpreted as "do not change" (but -1 can also be used).
		564
		565	Examples:
		566
		567	# same as "chown root path" in the shell:
		568	aio_chown "path", 0, -1;
		569	# same as above:
		570	aio_chown "path", 0, undef;
		571
		572
		573	=item aio_truncate $fh_or_path, $offset, $callback->($status)
		574
		575	Works like truncate(2) or ftruncate(2).
		576
		577
		578	=item aio_chmod $fh_or_path, $mode, $callback->($status)
		579
		580	Works like perl's C<chmod> function.
		581
		582
401	=item aio_unlink $pathname, $callback->($status)	583	=item aio_unlink $pathname, $callback->($status)
402		584
403	Asynchronously unlink (delete) a file and call the callback with the	585	Asynchronously unlink (delete) a file and call the callback with the
404	result code.	586	result code.
405		587
		588
406	=item aio_mknod $path, $mode, $dev, $callback->($status)	589	=item aio_mknod $path, $mode, $dev, $callback->($status)
407		590
408	[EXPERIMENTAL]	591	[EXPERIMENTAL]
409		592
410	Asynchronously create a device node (or fifo). See mknod(2).	593	Asynchronously create a device node (or fifo). See mknod(2).
411		594
412	The only (POSIX-) portable way of calling this function is:	595	The only (POSIX-) portable way of calling this function is:
413		596
414	aio_mknod $path, IO::AIO::S_IFIFO | $mode, 0, sub { ...	597	aio_mknod $path, IO::AIO::S_IFIFO | $mode, 0, sub { ...
		598
415		599
416	=item aio_link $srcpath, $dstpath, $callback->($status)	600	=item aio_link $srcpath, $dstpath, $callback->($status)
417		601
418	Asynchronously create a new link to the existing object at C<$srcpath> at	602	Asynchronously create a new link to the existing object at C<$srcpath> at
419	the path C<$dstpath> and call the callback with the result code.	603	the path C<$dstpath> and call the callback with the result code.
420		604
		605
421	=item aio_symlink $srcpath, $dstpath, $callback->($status)	606	=item aio_symlink $srcpath, $dstpath, $callback->($status)
422		607
423	Asynchronously create a new symbolic link to the existing object at C<$srcpath> at	608	Asynchronously create a new symbolic link to the existing object at C<$srcpath> at
424	the path C<$dstpath> and call the callback with the result code.	609	the path C<$dstpath> and call the callback with the result code.
		610
425		611
426	=item aio_readlink $path, $callback->($link)	612	=item aio_readlink $path, $callback->($link)
427		613
428	Asynchronously read the symlink specified by C<$path> and pass it to	614	Asynchronously read the symlink specified by C<$path> and pass it to
429	the callback. If an error occurs, nothing or undef gets passed to the	615	the callback. If an error occurs, nothing or undef gets passed to the
430	callback.	616	callback.
431		617
		618
432	=item aio_rename $srcpath, $dstpath, $callback->($status)	619	=item aio_rename $srcpath, $dstpath, $callback->($status)
433		620
434	Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as	621	Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as
435	rename(2) and call the callback with the result code.	622	rename(2) and call the callback with the result code.
		623
436		624
437	=item aio_mkdir $pathname, $mode, $callback->($status)	625	=item aio_mkdir $pathname, $mode, $callback->($status)
438		626
439	Asynchronously mkdir (create) a directory and call the callback with	627	Asynchronously mkdir (create) a directory and call the callback with
440	the result code. C<$mode> will be modified by the umask at the time the	628	the result code. C<$mode> will be modified by the umask at the time the
441	request is executed, so do not change your umask.	629	request is executed, so do not change your umask.
442		630
		631
443	=item aio_rmdir $pathname, $callback->($status)	632	=item aio_rmdir $pathname, $callback->($status)
444		633
445	Asynchronously rmdir (delete) a directory and call the callback with the	634	Asynchronously rmdir (delete) a directory and call the callback with the
446	result code.	635	result code.
		636
447		637
448	=item aio_readdir $pathname, $callback->($entries)	638	=item aio_readdir $pathname, $callback->($entries)
449		639
450	Unlike the POSIX call of the same name, C<aio_readdir> reads an entire	640	Unlike the POSIX call of the same name, C<aio_readdir> reads an entire
451	directory (i.e. opendir + readdir + closedir). The entries will not be	641	directory (i.e. opendir + readdir + closedir). The entries will not be
452	sorted, and will B<NOT> include the C<.> and C<..> entries.	642	sorted, and will B<NOT> include the C<.> and C<..> entries.
453		643
454	The callback a single argument which is either C<undef> or an array-ref	644	The callback is passed a single argument which is either C<undef> or an
455	with the filenames.	645	array-ref with the filenames.
		646
		647
		648	=item aio_readdirx $pathname, $flags, $callback->($entries, $flags)
		649
		650	Quite similar to C<aio_readdir>, but the C<$flags> argument allows to tune
		651	behaviour and output format. In case of an error, C<$entries> will be
		652	C<undef>.
		653
		654	The flags are a combination of the following constants, ORed together (the
		655	flags will also be passed to the callback, possibly modified):
		656
		657	=over 4
		658
		659	=item IO::AIO::READDIR_DENTS
		660
		661	When this flag is off, then the callback gets an arrayref with of names
		662	only (as with C<aio_readdir>), otherwise it gets an arrayref with
		663	C<[$name, $type, $inode]> arrayrefs, each describing a single directory
		664	entry in more detail.
		665
		666	C<$name> is the name of the entry.
		667
		668	C<$type> is one of the C<IO::AIO::DT_xxx> constants:
		669
		670	C<IO::AIO::DT_UNKNOWN>, C<IO::AIO::DT_FIFO>, C<IO::AIO::DT_CHR>, C<IO::AIO::DT_DIR>,
		671	C<IO::AIO::DT_BLK>, C<IO::AIO::DT_REG>, C<IO::AIO::DT_LNK>, C<IO::AIO::DT_SOCK>,
		672	C<IO::AIO::DT_WHT>.
		673
		674	C<IO::AIO::DT_UNKNOWN> means just that: readdir does not know. If you need to
		675	know, you have to run stat yourself. Also, for speed reasons, the C<$type>
		676	scalars are read-only: you can not modify them.
		677
		678	C<$inode> is the inode number (which might not be exact on systems with 64
		679	bit inode numbers and 32 bit perls). This field has unspecified content on
		680	systems that do not deliver the inode information.
		681
		682	=item IO::AIO::READDIR_DIRS_FIRST
		683
		684	When this flag is set, then the names will be returned in an order where
		685	likely directories come first. This is useful when you need to quickly
		686	find directories, or you want to find all directories while avoiding to
		687	stat() each entry.
		688
		689	If the system returns type information in readdir, then this is used
		690	to find directories directly. Otherwise, likely directories are files
		691	beginning with ".", or otherwise files with no dots, of which files with
		692	short names are tried first.
		693
		694	=item IO::AIO::READDIR_STAT_ORDER
		695
		696	When this flag is set, then the names will be returned in an order
		697	suitable for stat()'ing each one. That is, when you plan to stat()
		698	all files in the given directory, then the returned order will likely
		699	be fastest.
		700
		701	If both this flag and C<IO::AIO::READDIR_DIRS_FIRST> are specified, then
		702	the likely dirs come first, resulting in a less optimal stat order.
		703
		704	=item IO::AIO::READDIR_FOUND_UNKNOWN
		705
		706	This flag should not be set when calling C<aio_readdirx>. Instead, it
		707	is being set by C<aio_readdirx>, when any of the C<$type>'s found were
		708	C<IO::AIO::DT_UNKNOWN>. The absense of this flag therefore indicates that all
		709	C<$type>'s are known, which can be used to speed up some algorithms.
		710
		711	=back
		712
456		713
457	=item aio_load $path, $data, $callback->($status)	714	=item aio_load $path, $data, $callback->($status)
458		715
459	This is a composite request that tries to fully load the given file into	716	This is a composite request that tries to fully load the given file into
460	memory. Status is the same as with aio_read.	717	memory. Status is the same as with aio_read.
461		718
462	=cut	719	=cut
463		720
464	sub aio_load($$;$) {	721	sub aio_load($$;$) {
465	aio_block {
466	my ($path, undef, $cb) = @_;	722	my ($path, undef, $cb) = @_;
467	my $data = \$_[1];	723	my $data = \$_[1];
468		724
469	my $pri = aioreq_pri;	725	my $pri = aioreq_pri;
470	my $grp = aio_group $cb;	726	my $grp = aio_group $cb;
		727
		728	aioreq_pri $pri;
		729	add $grp aio_open $path, O_RDONLY, 0, sub {
		730	my $fh = shift
		731	or return $grp->result (-1);
471		732
472	aioreq_pri $pri;	733	aioreq_pri $pri;
473	add $grp aio_open $path, O_RDONLY, 0, sub {
474	my $fh = shift
475	or return $grp->result (-1);
476
477	aioreq_pri $pri;
478	add $grp aio_read $fh, 0, (-s $fh), $$data, 0, sub {	734	add $grp aio_read $fh, 0, (-s $fh), $$data, 0, sub {
479	$grp->result ($_[0]);	735	$grp->result ($_[0]);
480	};
481	};	736	};
482
483	$grp
484	}	737	};
		738
		739	$grp
485	}	740	}
486		741
487	=item aio_copy $srcpath, $dstpath, $callback->($status)	742	=item aio_copy $srcpath, $dstpath, $callback->($status)
488		743
489	Try to copy the I<file> (directories not supported as either source or	744	Try to copy the I<file> (directories not supported as either source or
490	destination) from C<$srcpath> to C<$dstpath> and call the callback with	745	destination) from C<$srcpath> to C<$dstpath> and call the callback with
491	the C<0> (error) or C<-1> ok.	746	a status of C<0> (ok) or C<-1> (error, see C<$!>).
492		747
493	This is a composite request that it creates the destination file with	748	This is a composite request that creates the destination file with
494	mode 0200 and copies the contents of the source file into it using	749	mode 0200 and copies the contents of the source file into it using
495	C<aio_sendfile>, followed by restoring atime, mtime, access mode and	750	C<aio_sendfile>, followed by restoring atime, mtime, access mode and
496	uid/gid, in that order.	751	uid/gid, in that order.
497		752
498	If an error occurs, the partial destination file will be unlinked, if	753	If an error occurs, the partial destination file will be unlinked, if
…		…
500	errors are being ignored.	755	errors are being ignored.
501		756
502	=cut	757	=cut
503		758
504	sub aio_copy($$;$) {	759	sub aio_copy($$;$) {
505	aio_block {
506	my ($src, $dst, $cb) = @_;	760	my ($src, $dst, $cb) = @_;
507		761
508	my $pri = aioreq_pri;	762	my $pri = aioreq_pri;
509	my $grp = aio_group $cb;	763	my $grp = aio_group $cb;
510		764
511	aioreq_pri $pri;	765	aioreq_pri $pri;
512	add $grp aio_open $src, O_RDONLY, 0, sub {	766	add $grp aio_open $src, O_RDONLY, 0, sub {
513	if (my $src_fh = $_[0]) {	767	if (my $src_fh = $_[0]) {
514	my @stat = stat $src_fh;	768	my @stat = stat $src_fh; # hmm, might block over nfs?
515		769
516	aioreq_pri $pri;	770	aioreq_pri $pri;
517	add $grp aio_open $dst, O_CREAT | O_WRONLY | O_TRUNC, 0200, sub {	771	add $grp aio_open $dst, O_CREAT | O_WRONLY | O_TRUNC, 0200, sub {
518	if (my $dst_fh = $_[0]) {	772	if (my $dst_fh = $_[0]) {
519	aioreq_pri $pri;	773	aioreq_pri $pri;
520	add $grp aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub {	774	add $grp aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub {
521	if ($_[0] == $stat[7]) {	775	if ($_[0] == $stat[7]) {
522	$grp->result (0);	776	$grp->result (0);
523	close $src_fh;	777	close $src_fh;
524		778
525	# those should not normally block. should. should.
526	utime $stat[8], $stat[9], $dst;
527	chmod $stat[2] & 07777, $dst_fh;
528	chown $stat[4], $stat[5], $dst_fh;
529	close $dst_fh;
530	} else {	779	my $ch = sub {
531	$grp->result (-1);
532	close $src_fh;
533	close $dst_fh;
534
535	aioreq $pri;	780	aioreq_pri $pri;
		781	add $grp aio_chmod $dst_fh, $stat[2] & 07777, sub {
		782	aioreq_pri $pri;
		783	add $grp aio_chown $dst_fh, $stat[4], $stat[5], sub {
		784	aioreq_pri $pri;
536	add $grp aio_unlink $dst;	785	add $grp aio_close $dst_fh;
		786	}
		787	};
537	}	788	};
		789
		790	aioreq_pri $pri;
		791	add $grp aio_utime $dst_fh, $stat[8], $stat[9], sub {
		792	if ($_[0] < 0 && $! == ENOSYS) {
		793	aioreq_pri $pri;
		794	add $grp aio_utime $dst, $stat[8], $stat[9], $ch;
		795	} else {
		796	$ch->();
		797	}
		798	};
		799	} else {
		800	$grp->result (-1);
		801	close $src_fh;
		802	close $dst_fh;
		803
		804	aioreq $pri;
		805	add $grp aio_unlink $dst;
538	};	806	}
539	} else {
540	$grp->result (-1);
541	}	807	};
		808	} else {
		809	$grp->result (-1);
542	},	810	}
543
544	} else {
545	$grp->result (-1);
546	}	811	},
		812
		813	} else {
		814	$grp->result (-1);
547	};	815	}
548
549	$grp
550	}	816	};
		817
		818	$grp
551	}	819	}
552		820
553	=item aio_move $srcpath, $dstpath, $callback->($status)	821	=item aio_move $srcpath, $dstpath, $callback->($status)
554		822
555	Try to move the I<file> (directories not supported as either source or	823	Try to move the I<file> (directories not supported as either source or
556	destination) from C<$srcpath> to C<$dstpath> and call the callback with	824	destination) from C<$srcpath> to C<$dstpath> and call the callback with
557	the C<0> (error) or C<-1> ok.	825	a status of C<0> (ok) or C<-1> (error, see C<$!>).
558		826
559	This is a composite request that tries to rename(2) the file first. If	827	This is a composite request that tries to rename(2) the file first; if
560	rename files with C<EXDEV>, it copies the file with C<aio_copy> and, if	828	rename fails with C<EXDEV>, it copies the file with C<aio_copy> and, if
561	that is successful, unlinking the C<$srcpath>.	829	that is successful, unlinks the C<$srcpath>.
562		830
563	=cut	831	=cut
564		832
565	sub aio_move($$;$) {	833	sub aio_move($$;$) {
566	aio_block {
567	my ($src, $dst, $cb) = @_;	834	my ($src, $dst, $cb) = @_;
568		835
569	my $pri = aioreq_pri;	836	my $pri = aioreq_pri;
570	my $grp = aio_group $cb;	837	my $grp = aio_group $cb;
571		838
572	aioreq_pri $pri;	839	aioreq_pri $pri;
573	add $grp aio_rename $src, $dst, sub {	840	add $grp aio_rename $src, $dst, sub {
574	if ($_[0] && $! == EXDEV) {	841	if ($_[0] && $! == EXDEV) {
575	aioreq_pri $pri;	842	aioreq_pri $pri;
576	add $grp aio_copy $src, $dst, sub {	843	add $grp aio_copy $src, $dst, sub {
577	$grp->result ($_[0]);
578
579	if (!$_[0]) {
580	aioreq_pri $pri;
581	add $grp aio_unlink $src;
582	}
583	};
584	} else {
585	$grp->result ($_[0]);	844	$grp->result ($_[0]);
		845
		846	if (!$_[0]) {
		847	aioreq_pri $pri;
		848	add $grp aio_unlink $src;
		849	}
586	}	850	};
		851	} else {
		852	$grp->result ($_[0]);
587	};	853	}
588
589	$grp
590	}	854	};
		855
		856	$grp
591	}	857	}
592		858
593	=item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs)	859	=item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs)
594		860
595	Scans a directory (similar to C<aio_readdir>) but additionally tries to	861	Scans a directory (similar to C<aio_readdir>) but additionally tries to
…		…
615		881
616	Implementation notes.	882	Implementation notes.
617		883
618	The C<aio_readdir> cannot be avoided, but C<stat()>'ing every entry can.	884	The C<aio_readdir> cannot be avoided, but C<stat()>'ing every entry can.
619		885
		886	If readdir returns file type information, then this is used directly to
		887	find directories.
		888
620	After reading the directory, the modification time, size etc. of the	889	Otherwise, after reading the directory, the modification time, size etc.
621	directory before and after the readdir is checked, and if they match (and	890	of the directory before and after the readdir is checked, and if they
622	isn't the current time), the link count will be used to decide how many	891	match (and isn't the current time), the link count will be used to decide
623	entries are directories (if >= 2). Otherwise, no knowledge of the number	892	how many entries are directories (if >= 2). Otherwise, no knowledge of the
624	of subdirectories will be assumed.	893	number of subdirectories will be assumed.
625		894
626	Then entries will be sorted into likely directories (everything without	895	Then entries will be sorted into likely directories a non-initial dot
627	a non-initial dot currently) and likely non-directories (everything	896	currently) and likely non-directories (see C<aio_readdirx>). Then every
628	else). Then every entry plus an appended C</.> will be C<stat>'ed,	897	entry plus an appended C</.> will be C<stat>'ed, likely directories first,
629	likely directories first. If that succeeds, it assumes that the entry	898	in order of their inode numbers. If that succeeds, it assumes that the
630	is a directory or a symlink to directory (which will be checked	899	entry is a directory or a symlink to directory (which will be checked
631	seperately). This is often faster than stat'ing the entry itself because	900	seperately). This is often faster than stat'ing the entry itself because
632	filesystems might detect the type of the entry without reading the inode	901	filesystems might detect the type of the entry without reading the inode
633	data (e.g. ext2fs filetype feature).	902	data (e.g. ext2fs filetype feature), even on systems that cannot return
		903	the filetype information on readdir.
634		904
635	If the known number of directories (link count - 2) has been reached, the	905	If the known number of directories (link count - 2) has been reached, the
636	rest of the entries is assumed to be non-directories.	906	rest of the entries is assumed to be non-directories.
637		907
638	This only works with certainty on POSIX (= UNIX) filesystems, which	908	This only works with certainty on POSIX (= UNIX) filesystems, which
…		…
643	directory counting heuristic.	913	directory counting heuristic.
644		914
645	=cut	915	=cut
646		916
647	sub aio_scandir($$;$) {	917	sub aio_scandir($$;$) {
648	aio_block {
649	my ($path, $maxreq, $cb) = @_;	918	my ($path, $maxreq, $cb) = @_;
650		919
651	my $pri = aioreq_pri;	920	my $pri = aioreq_pri;
652		921
653	my $grp = aio_group $cb;	922	my $grp = aio_group $cb;
654		923
655	$maxreq = 4 if $maxreq <= 0;	924	$maxreq = 4 if $maxreq <= 0;
656		925
657	# stat once	926	# stat once
		927	aioreq_pri $pri;
		928	add $grp aio_stat $path, sub {
		929	return $grp->result () if $_[0];
		930	my $now = time;
		931	my $hash1 = join ":", (stat _)[0,1,3,7,9];
		932
		933	# read the directory entries
658	aioreq_pri $pri;	934	aioreq_pri $pri;
659	add $grp aio_stat $path, sub {	935	add $grp aio_readdirx $path, READDIR_DIRS_FIRST, sub {
		936	my $entries = shift
660	return $grp->result () if $_[0];	937	or return $grp->result ();
661	my $now = time;
662	my $hash1 = join ":", (stat _)[0,1,3,7,9];
663		938
664	# read the directory entries	939	# stat the dir another time
665	aioreq_pri $pri;	940	aioreq_pri $pri;
666	add $grp aio_readdir $path, sub {
667	my $entries = shift
668	or return $grp->result ();
669
670	# stat the dir another time
671	aioreq_pri $pri;
672	add $grp aio_stat $path, sub {	941	add $grp aio_stat $path, sub {
673	my $hash2 = join ":", (stat _)[0,1,3,7,9];	942	my $hash2 = join ":", (stat _)[0,1,3,7,9];
674		943
675	my $ndirs;	944	my $ndirs;
676		945
677	# take the slow route if anything looks fishy	946	# take the slow route if anything looks fishy
678	if ($hash1 ne $hash2 or (stat _)[9] == $now) {	947	if ($hash1 ne $hash2 or (stat _)[9] == $now) {
679	$ndirs = -1;	948	$ndirs = -1;
680	} else {	949	} else {
681	# if nlink == 2, we are finished	950	# if nlink == 2, we are finished
682	# on non-posix-fs's, we rely on nlink < 2	951	# for non-posix-fs's, we rely on nlink < 2
683	$ndirs = (stat _)[3] - 2	952	$ndirs = (stat _)[3] - 2
684	or return $grp->result ([], $entries);	953	or return $grp->result ([], $entries);
685	}	954	}
686		955
687	# sort into likely dirs and likely nondirs
688	# dirs == files without ".", short entries first
689	$entries = [map $_->[0],
690	sort { $b->[1] cmp $a->[1] }
691	map [$_, sprintf "%s%04d", (/.\./ ? "1" : "0"), length],
692	@$entries];
693
694	my (@dirs, @nondirs);	956	my (@dirs, @nondirs);
695		957
696	my $statgrp = add $grp aio_group sub {	958	my $statgrp = add $grp aio_group sub {
697	$grp->result (\@dirs, \@nondirs);	959	$grp->result (\@dirs, \@nondirs);
698	};	960	};
699		961
700	limit $statgrp $maxreq;	962	limit $statgrp $maxreq;
701	feed $statgrp sub {	963	feed $statgrp sub {
702	return unless @$entries;	964	return unless @$entries;
703	my $entry = pop @$entries;	965	my $entry = shift @$entries;
704		966
705	aioreq_pri $pri;	967	aioreq_pri $pri;
706	add $statgrp aio_stat "$path/$entry/.", sub {	968	add $statgrp aio_stat "$path/$entry/.", sub {
707	if ($_[0] < 0) {	969	if ($_[0] < 0) {
708	push @nondirs, $entry;	970	push @nondirs, $entry;
709	} else {	971	} else {
710	# need to check for real directory	972	# need to check for real directory
711	aioreq_pri $pri;	973	aioreq_pri $pri;
712	add $statgrp aio_lstat "$path/$entry", sub {	974	add $statgrp aio_lstat "$path/$entry", sub {
713	if (-d _) {	975	if (-d _) {
714	push @dirs, $entry;	976	push @dirs, $entry;
715		977
716	unless (--$ndirs) {	978	unless (--$ndirs) {
717	push @nondirs, @$entries;	979	push @nondirs, @$entries;
718	feed $statgrp;	980	feed $statgrp;
719	}
720	} else {
721	push @nondirs, $entry;
722	}	981	}
		982	} else {
		983	push @nondirs, $entry;
723	}	984	}
724	}	985	}
725	};	986	}
726	};	987	};
727	};	988	};
728	};	989	};
729	};	990	};
730
731	$grp
732	}	991	};
		992
		993	$grp
733	}	994	}
734		995
735	=item aio_rmtree $path, $callback->($status)	996	=item aio_rmtree $path, $callback->($status)
736		997
737	Delete a directory tree starting (and including) C<$path>, return the	998	Delete a directory tree starting (and including) C<$path>, return the
…		…
741		1002
742	=cut	1003	=cut
743		1004
744	sub aio_rmtree;	1005	sub aio_rmtree;
745	sub aio_rmtree($;$) {	1006	sub aio_rmtree($;$) {
746	aio_block {
747	my ($path, $cb) = @_;	1007	my ($path, $cb) = @_;
748		1008
749	my $pri = aioreq_pri;	1009	my $pri = aioreq_pri;
750	my $grp = aio_group $cb;	1010	my $grp = aio_group $cb;
751		1011
752	aioreq_pri $pri;	1012	aioreq_pri $pri;
753	add $grp aio_scandir $path, 0, sub {	1013	add $grp aio_scandir $path, 0, sub {
754	my ($dirs, $nondirs) = @_;	1014	my ($dirs, $nondirs) = @_;
755		1015
756	my $dirgrp = aio_group sub {	1016	my $dirgrp = aio_group sub {
757	add $grp aio_rmdir $path, sub {	1017	add $grp aio_rmdir $path, sub {
758	$grp->result ($_[0]);	1018	$grp->result ($_[0]);
759	};
760	};	1019	};
761
762	(aioreq_pri $pri), add $dirgrp aio_rmtree "$path/$_" for @$dirs;
763	(aioreq_pri $pri), add $dirgrp aio_unlink "$path/$_" for @$nondirs;
764
765	add $grp $dirgrp;
766	};	1020	};
767		1021
768	$grp	1022	(aioreq_pri $pri), add $dirgrp aio_rmtree "$path/$_" for @$dirs;
		1023	(aioreq_pri $pri), add $dirgrp aio_unlink "$path/$_" for @$nondirs;
		1024
		1025	add $grp $dirgrp;
769	}	1026	};
		1027
		1028	$grp
770	}	1029	}
		1030
		1031	=item aio_sync $callback->($status)
		1032
		1033	Asynchronously call sync and call the callback when finished.
771		1034
772	=item aio_fsync $fh, $callback->($status)	1035	=item aio_fsync $fh, $callback->($status)
773		1036
774	Asynchronously call fsync on the given filehandle and call the callback	1037	Asynchronously call fsync on the given filehandle and call the callback
775	with the fsync result code.	1038	with the fsync result code.
…		…
779	Asynchronously call fdatasync on the given filehandle and call the	1042	Asynchronously call fdatasync on the given filehandle and call the
780	callback with the fdatasync result code.	1043	callback with the fdatasync result code.
781		1044
782	If this call isn't available because your OS lacks it or it couldn't be	1045	If this call isn't available because your OS lacks it or it couldn't be
783	detected, it will be emulated by calling C<fsync> instead.	1046	detected, it will be emulated by calling C<fsync> instead.
		1047
		1048	=item aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status)
		1049
		1050	Sync the data portion of the file specified by C<$offset> and C<$length>
		1051	to disk (but NOT the metadata), by calling the Linux-specific
		1052	sync_file_range call. If sync_file_range is not available or it returns
		1053	ENOSYS, then fdatasync or fsync is being substituted.
		1054
		1055	C<$flags> can be a combination of C<IO::AIO::SYNC_FILE_RANGE_WAIT_BEFORE>,
		1056	C<IO::AIO::SYNC_FILE_RANGE_WRITE> and
		1057	C<IO::AIO::SYNC_FILE_RANGE_WAIT_AFTER>: refer to the sync_file_range
		1058	manpage for details.
		1059
		1060	=item aio_pathsync $path, $callback->($status)
		1061
		1062	This request tries to open, fsync and close the given path. This is a
		1063	composite request intended to sync directories after directory operations
		1064	(E.g. rename). This might not work on all operating systems or have any
		1065	specific effect, but usually it makes sure that directory changes get
		1066	written to disc. It works for anything that can be opened for read-only,
		1067	not just directories.
		1068
		1069	Future versions of this function might fall back to other methods when
		1070	C<fsync> on the directory fails (such as calling C<sync>).
		1071
		1072	Passes C<0> when everything went ok, and C<-1> on error.
		1073
		1074	=cut
		1075
		1076	sub aio_pathsync($;$) {
		1077	my ($path, $cb) = @_;
		1078
		1079	my $pri = aioreq_pri;
		1080	my $grp = aio_group $cb;
		1081
		1082	aioreq_pri $pri;
		1083	add $grp aio_open $path, O_RDONLY, 0, sub {
		1084	my ($fh) = @_;
		1085	if ($fh) {
		1086	aioreq_pri $pri;
		1087	add $grp aio_fsync $fh, sub {
		1088	$grp->result ($_[0]);
		1089
		1090	aioreq_pri $pri;
		1091	add $grp aio_close $fh;
		1092	};
		1093	} else {
		1094	$grp->result (-1);
		1095	}
		1096	};
		1097
		1098	$grp
		1099	}
		1100
		1101	=item aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
		1102
		1103	This is a rather advanced IO::AIO call, which only works on mmap(2)ed
		1104	scalars (see the C<IO::AIO::mmap> function, although it also works on data
		1105	scalars managed by the L<Sys::Mmap> or L<Mmap> modules, note that the
		1106	scalar must only be modified in-place while an aio operation is pending on
		1107	it).
		1108
		1109	It calls the C<msync> function of your OS, if available, with the memory
		1110	area starting at C<$offset> in the string and ending C<$length> bytes
		1111	later. If C<$length> is negative, counts from the end, and if C<$length>
		1112	is C<undef>, then it goes till the end of the string. The flags can be
		1113	a combination of C<IO::AIO::MS_ASYNC>, C<IO::AIO::MS_INVALIDATE> and
		1114	C<IO::AIO::MS_SYNC>.
		1115
		1116	=item aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
		1117
		1118	This is a rather advanced IO::AIO call, which works best on mmap(2)ed
		1119	scalars.
		1120
		1121	It touches (reads or writes) all memory pages in the specified
		1122	range inside the scalar. All caveats and parameters are the same
		1123	as for C<aio_msync>, above, except for flags, which must be either
		1124	C<0> (which reads all pages and ensures they are instantiated) or
		1125	C<IO::AIO::MT_MODIFY>, which modifies the memory page s(by reading and
		1126	writing an octet from it, which dirties the page).
		1127
		1128	=item aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status)
		1129
		1130	This is a rather advanced IO::AIO call, which works best on mmap(2)ed
		1131	scalars.
		1132
		1133	It reads in all the pages of the underlying storage into memory (if any)
		1134	and locks them, so they are not getting swapped/paged out or removed.
		1135
		1136	If C<$length> is undefined, then the scalar will be locked till the end.
		1137
		1138	On systems that do not implement C<mlock>, this function returns C<-1>
		1139	and sets errno to C<ENOSYS>.
		1140
		1141	Note that the corresponding C<munlock> is synchronous and is
		1142	documented under L<MISCELLANEOUS FUNCTIONS>.
		1143
		1144	Example: open a file, mmap and mlock it - both will be undone when
		1145	C<$data> gets destroyed.
		1146
		1147	open my $fh, "<", $path or die "$path: $!";
		1148	my $data;
		1149	IO::AIO::mmap $data, -s $fh, IO::AIO::PROT_READ, IO::AIO::MAP_SHARED, $fh;
		1150	aio_mlock $data; # mlock in background
		1151
		1152	=item aio_mlockall $flags, $callback->($status)
		1153
		1154	Calls the C<mlockall> function with the given C<$flags> (a combination of
		1155	C<IO::AIO::MCL_CURRENT> and C<IO::AIO::MCL_FUTURE>).
		1156
		1157	On systems that do not implement C<mlockall>, this function returns C<-1>
		1158	and sets errno to C<ENOSYS>.
		1159
		1160	Note that the corresponding C<munlockall> is synchronous and is
		1161	documented under L<MISCELLANEOUS FUNCTIONS>.
		1162
		1163	Example: asynchronously lock all current and future pages into memory.
		1164
		1165	aio_mlockall IO::AIO::MCL_FUTURE;
784		1166
785	=item aio_group $callback->(...)	1167	=item aio_group $callback->(...)
786		1168
787	This is a very special aio request: Instead of doing something, it is a	1169	This is a very special aio request: Instead of doing something, it is a
788	container for other aio requests, which is useful if you want to bundle	1170	container for other aio requests, which is useful if you want to bundle
…		…
838	=item cancel $req	1220	=item cancel $req
839		1221
840	Cancels the request, if possible. Has the effect of skipping execution	1222	Cancels the request, if possible. Has the effect of skipping execution
841	when entering the B<execute> state and skipping calling the callback when	1223	when entering the B<execute> state and skipping calling the callback when
842	entering the the B<result> state, but will leave the request otherwise	1224	entering the the B<result> state, but will leave the request otherwise
843	untouched. That means that requests that currently execute will not be	1225	untouched (with the exception of readdir). That means that requests that
844	stopped and resources held by the request will not be freed prematurely.	1226	currently execute will not be stopped and resources held by the request
		1227	will not be freed prematurely.
845		1228
846	=item cb $req $callback->(...)	1229	=item cb $req $callback->(...)
847		1230
848	Replace (or simply set) the callback registered to the request.	1231	Replace (or simply set) the callback registered to the request.
849		1232
…		…
900	Their lifetime, simplified, looks like this: when they are empty, they	1283	Their lifetime, simplified, looks like this: when they are empty, they
901	will finish very quickly. If they contain only requests that are in the	1284	will finish very quickly. If they contain only requests that are in the
902	C<done> state, they will also finish. Otherwise they will continue to	1285	C<done> state, they will also finish. Otherwise they will continue to
903	exist.	1286	exist.
904		1287
905	That means after creating a group you have some time to add requests. And	1288	That means after creating a group you have some time to add requests
906	in the callbacks of those requests, you can add further requests to the	1289	(precisely before the callback has been invoked, which is only done within
907	group. And only when all those requests have finished will the the group	1290	the C<poll_cb>). And in the callbacks of those requests, you can add
908	itself finish.	1291	further requests to the group. And only when all those requests have
		1292	finished will the the group itself finish.
909		1293
910	=over 4	1294	=over 4
911		1295
912	=item add $grp ...	1296	=item add $grp ...
913		1297
…		…
922	=item $grp->cancel_subs	1306	=item $grp->cancel_subs
923		1307
924	Cancel all subrequests and clears any feeder, but not the group request	1308	Cancel all subrequests and clears any feeder, but not the group request
925	itself. Useful when you queued a lot of events but got a result early.	1309	itself. Useful when you queued a lot of events but got a result early.
926		1310
		1311	The group request will finish normally (you cannot add requests to the
		1312	group).
		1313
927	=item $grp->result (...)	1314	=item $grp->result (...)
928		1315
929	Set the result value(s) that will be passed to the group callback when all	1316	Set the result value(s) that will be passed to the group callback when all
930	subrequests have finished and set thre groups errno to the current value	1317	subrequests have finished and set the groups errno to the current value
931	of errno (just like calling C<errno> without an error number). By default,	1318	of errno (just like calling C<errno> without an error number). By default,
932	no argument will be passed and errno is zero.	1319	no argument will be passed and errno is zero.
933		1320
934	=item $grp->errno ([$errno])	1321	=item $grp->errno ([$errno])
935		1322
…		…
946	=item feed $grp $callback->($grp)	1333	=item feed $grp $callback->($grp)
947		1334
948	Sets a feeder/generator on this group: every group can have an attached	1335	Sets a feeder/generator on this group: every group can have an attached
949	generator that generates requests if idle. The idea behind this is that,	1336	generator that generates requests if idle. The idea behind this is that,
950	although you could just queue as many requests as you want in a group,	1337	although you could just queue as many requests as you want in a group,
951	this might starve other requests for a potentially long time. For	1338	this might starve other requests for a potentially long time. For example,
952	example, C<aio_scandir> might generate hundreds of thousands C<aio_stat>	1339	C<aio_scandir> might generate hundreds of thousands C<aio_stat> requests,
953	requests, delaying any later requests for a long time.	1340	delaying any later requests for a long time.
954		1341
955	To avoid this, and allow incremental generation of requests, you can	1342	To avoid this, and allow incremental generation of requests, you can
956	instead a group and set a feeder on it that generates those requests. The	1343	instead a group and set a feeder on it that generates those requests. The
957	feed callback will be called whenever there are few enough (see C<limit>,	1344	feed callback will be called whenever there are few enough (see C<limit>,
958	below) requests active in the group itself and is expected to queue more	1345	below) requests active in the group itself and is expected to queue more
…		…
962	not impose any limits).	1349	not impose any limits).
963		1350
964	If the feed does not queue more requests when called, it will be	1351	If the feed does not queue more requests when called, it will be
965	automatically removed from the group.	1352	automatically removed from the group.
966		1353
967	If the feed limit is C<0>, it will be set to C<2> automatically.	1354	If the feed limit is C<0> when this method is called, it will be set to
		1355	C<2> automatically.
968		1356
969	Example:	1357	Example:
970		1358
971	# stat all files in @files, but only ever use four aio requests concurrently:	1359	# stat all files in @files, but only ever use four aio requests concurrently:
972		1360
…		…
984	Sets the feeder limit for the group: The feeder will be called whenever	1372	Sets the feeder limit for the group: The feeder will be called whenever
985	the group contains less than this many requests.	1373	the group contains less than this many requests.
986		1374
987	Setting the limit to C<0> will pause the feeding process.	1375	Setting the limit to C<0> will pause the feeding process.
988		1376
		1377	The default value for the limit is C<0>, but note that setting a feeder
		1378	automatically bumps it up to C<2>.
		1379
989	=back	1380	=back
990		1381
991	=head2 SUPPORT FUNCTIONS	1382	=head2 SUPPORT FUNCTIONS
992		1383
993	=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION	1384	=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION
…		…
995	=over 4	1386	=over 4
996		1387
997	=item $fileno = IO::AIO::poll_fileno	1388	=item $fileno = IO::AIO::poll_fileno
998		1389
999	Return the I<request result pipe file descriptor>. This filehandle must be	1390	Return the I<request result pipe file descriptor>. This filehandle must be
1000	polled for reading by some mechanism outside this module (e.g. Event or	1391	polled for reading by some mechanism outside this module (e.g. EV, Glib,
1001	select, see below or the SYNOPSIS). If the pipe becomes readable you have	1392	select and so on, see below or the SYNOPSIS). If the pipe becomes readable
1002	to call C<poll_cb> to check the results.	1393	you have to call C<poll_cb> to check the results.
1003		1394
1004	See C<poll_cb> for an example.	1395	See C<poll_cb> for an example.
1005		1396
1006	=item IO::AIO::poll_cb	1397	=item IO::AIO::poll_cb
1007		1398
1008	Process some outstanding events on the result pipe. You have to call this	1399	Process some outstanding events on the result pipe. You have to call this
1009	regularly. Returns the number of events processed. Returns immediately	1400	regularly. Returns C<0> if all events could be processed, or C<-1> if it
		1401	returned earlier for whatever reason. Returns immediately when no events
1010	when no events are outstanding. The amount of events processed depends on	1402	are outstanding. The amount of events processed depends on the settings of
1011	the settings of C<IO::AIO::max_poll_req> and C<IO::AIO::max_poll_time>.	1403	C<IO::AIO::max_poll_req> and C<IO::AIO::max_poll_time>.
1012		1404
1013	If not all requests were processed for whatever reason, the filehandle	1405	If not all requests were processed for whatever reason, the filehandle
1014	will still be ready when C<poll_cb> returns.	1406	will still be ready when C<poll_cb> returns, so normally you don't have to
		1407	do anything special to have it called later.
1015		1408
1016	Example: Install an Event watcher that automatically calls	1409	Example: Install an Event watcher that automatically calls
1017	IO::AIO::poll_cb with high priority:	1410	IO::AIO::poll_cb with high priority (more examples can be found in the
		1411	SYNOPSIS section, at the top of this document):
1018		1412
1019	Event->io (fd => IO::AIO::poll_fileno,	1413	Event->io (fd => IO::AIO::poll_fileno,
1020	poll => 'r', async => 1,	1414	poll => 'r', async => 1,
1021	cb => \&IO::AIO::poll_cb);	1415	cb => \&IO::AIO::poll_cb);
		1416
		1417	=item IO::AIO::poll_wait
		1418
		1419	If there are any outstanding requests and none of them in the result
		1420	phase, wait till the result filehandle becomes ready for reading (simply
		1421	does a C<select> on the filehandle. This is useful if you want to
		1422	synchronously wait for some requests to finish).
		1423
		1424	See C<nreqs> for an example.
		1425
		1426	=item IO::AIO::poll
		1427
		1428	Waits until some requests have been handled.
		1429
		1430	Returns the number of requests processed, but is otherwise strictly
		1431	equivalent to:
		1432
		1433	IO::AIO::poll_wait, IO::AIO::poll_cb
		1434
		1435	=item IO::AIO::flush
		1436
		1437	Wait till all outstanding AIO requests have been handled.
		1438
		1439	Strictly equivalent to:
		1440
		1441	IO::AIO::poll_wait, IO::AIO::poll_cb
		1442	while IO::AIO::nreqs;
1022		1443
1023	=item IO::AIO::max_poll_reqs $nreqs	1444	=item IO::AIO::max_poll_reqs $nreqs
1024		1445
1025	=item IO::AIO::max_poll_time $seconds	1446	=item IO::AIO::max_poll_time $seconds
1026		1447
…		…
1051	# use a low priority so other tasks have priority	1472	# use a low priority so other tasks have priority
1052	Event->io (fd => IO::AIO::poll_fileno,	1473	Event->io (fd => IO::AIO::poll_fileno,
1053	poll => 'r', nice => 1,	1474	poll => 'r', nice => 1,
1054	cb => &IO::AIO::poll_cb);	1475	cb => &IO::AIO::poll_cb);
1055		1476
1056	=item IO::AIO::poll_wait
1057
1058	If there are any outstanding requests and none of them in the result
1059	phase, wait till the result filehandle becomes ready for reading (simply
1060	does a C<select> on the filehandle. This is useful if you want to
1061	synchronously wait for some requests to finish).
1062
1063	See C<nreqs> for an example.
1064
1065	=item IO::AIO::poll
1066
1067	Waits until some requests have been handled.
1068
1069	Returns the number of requests processed, but is otherwise strictly
1070	equivalent to:
1071
1072	IO::AIO::poll_wait, IO::AIO::poll_cb
1073
1074	=item IO::AIO::flush
1075
1076	Wait till all outstanding AIO requests have been handled.
1077
1078	Strictly equivalent to:
1079
1080	IO::AIO::poll_wait, IO::AIO::poll_cb
1081	while IO::AIO::nreqs;
1082
1083	=back	1477	=back
1084		1478
1085	=head3 CONTROLLING THE NUMBER OF THREADS	1479	=head3 CONTROLLING THE NUMBER OF THREADS
1086		1480
1087	=over	1481	=over
…		…
1133		1527
1134	The default is probably ok in most situations, especially if thread	1528	The default is probably ok in most situations, especially if thread
1135	creation is fast. If thread creation is very slow on your system you might	1529	creation is fast. If thread creation is very slow on your system you might
1136	want to use larger values.	1530	want to use larger values.
1137		1531
1138	=item $oldmaxreqs = IO::AIO::max_outstanding $maxreqs	1532	=item IO::AIO::max_outstanding $maxreqs
1139		1533
1140	This is a very bad function to use in interactive programs because it	1534	This is a very bad function to use in interactive programs because it
1141	blocks, and a bad way to reduce concurrency because it is inexact: Better	1535	blocks, and a bad way to reduce concurrency because it is inexact: Better
1142	use an C<aio_group> together with a feed callback.	1536	use an C<aio_group> together with a feed callback.
1143		1537
1144	Sets the maximum number of outstanding requests to C<$nreqs>. If you	1538	Sets the maximum number of outstanding requests to C<$nreqs>. If you
1145	to queue up more than this number of requests, the next call to the	1539	do queue up more than this number of requests, the next call to the
1146	C<poll_cb> (and C<poll_some> and other functions calling C<poll_cb>)	1540	C<poll_cb> (and C<poll_some> and other functions calling C<poll_cb>)
1147	function will block until the limit is no longer exceeded.	1541	function will block until the limit is no longer exceeded.
1148		1542
1149	The default value is very large, so there is no practical limit on the	1543	The default value is very large, so there is no practical limit on the
1150	number of outstanding requests.	1544	number of outstanding requests.
1151		1545
1152	You can still queue as many requests as you want. Therefore,	1546	You can still queue as many requests as you want. Therefore,
1153	C<max_oustsanding> is mainly useful in simple scripts (with low values) or	1547	C<max_outstanding> is mainly useful in simple scripts (with low values) or
1154	as a stop gap to shield against fatal memory overflow (with large values).	1548	as a stop gap to shield against fatal memory overflow (with large values).
1155		1549
1156	=back	1550	=back
1157		1551
1158	=head3 STATISTICAL INFORMATION	1552	=head3 STATISTICAL INFORMATION
…		…
1179	Returns the number of requests currently in the pending state (executed,	1573	Returns the number of requests currently in the pending state (executed,
1180	but not yet processed by poll_cb).	1574	but not yet processed by poll_cb).
1181		1575
1182	=back	1576	=back
1183		1577
		1578	=head3 MISCELLANEOUS FUNCTIONS
		1579
		1580	IO::AIO implements some functions that might be useful, but are not
		1581	asynchronous.
		1582
		1583	=over 4
		1584
		1585	=item IO::AIO::sendfile $ofh, $ifh, $offset, $count
		1586
		1587	Calls the C<eio_sendfile_sync> function, which is like C<aio_sendfile>,
		1588	but is blocking (this makes most sense if you know the input data is
		1589	likely cached already and the output filehandle is set to non-blocking
		1590	operations).
		1591
		1592	Returns the number of bytes copied, or C<-1> on error.
		1593
		1594	=item IO::AIO::fadvise $fh, $offset, $len, $advice
		1595
		1596	Simply calls the C<posix_fadvise> function (see its
		1597	manpage for details). The following advice constants are
		1598	avaiable: C<IO::AIO::FADV_NORMAL>, C<IO::AIO::FADV_SEQUENTIAL>,
		1599	C<IO::AIO::FADV_RANDOM>, C<IO::AIO::FADV_NOREUSE>,
		1600	C<IO::AIO::FADV_WILLNEED>, C<IO::AIO::FADV_DONTNEED>.
		1601
		1602	On systems that do not implement C<posix_fadvise>, this function returns
		1603	ENOSYS, otherwise the return value of C<posix_fadvise>.
		1604
		1605	=item IO::AIO::madvise $scalar, $offset, $len, $advice
		1606
		1607	Simply calls the C<posix_madvise> function (see its
		1608	manpage for details). The following advice constants are
		1609	avaiable: C<IO::AIO::MADV_NORMAL>, C<IO::AIO::MADV_SEQUENTIAL>,
		1610	C<IO::AIO::MADV_RANDOM>, C<IO::AIO::MADV_WILLNEED>, C<IO::AIO::MADV_DONTNEED>.
		1611
		1612	On systems that do not implement C<posix_madvise>, this function returns
		1613	ENOSYS, otherwise the return value of C<posix_madvise>.
		1614
		1615	=item IO::AIO::mprotect $scalar, $offset, $len, $protect
		1616
		1617	Simply calls the C<mprotect> function on the preferably AIO::mmap'ed
		1618	$scalar (see its manpage for details). The following protect
		1619	constants are avaiable: C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_READ>,
		1620	C<IO::AIO::PROT_WRITE>, C<IO::AIO::PROT_EXEC>.
		1621
		1622	On systems that do not implement C<mprotect>, this function returns
		1623	ENOSYS, otherwise the return value of C<mprotect>.
		1624
		1625	=item IO::AIO::mmap $scalar, $length, $prot, $flags, $fh[, $offset]
		1626
		1627	Memory-maps a file (or anonymous memory range) and attaches it to the
		1628	given C<$scalar>, which will act like a string scalar.
		1629
		1630	The only operations allowed on the scalar are C<substr>/C<vec> that don't
		1631	change the string length, and most read-only operations such as copying it
		1632	or searching it with regexes and so on.
		1633
		1634	Anything else is unsafe and will, at best, result in memory leaks.
		1635
		1636	The memory map associated with the C<$scalar> is automatically removed
		1637	when the C<$scalar> is destroyed, or when the C<IO::AIO::mmap> or
		1638	C<IO::AIO::munmap> functions are called.
		1639
		1640	This calls the C<mmap>(2) function internally. See your system's manual
		1641	page for details on the C<$length>, C<$prot> and C<$flags> parameters.
		1642
		1643	The C<$length> must be larger than zero and smaller than the actual
		1644	filesize.
		1645
		1646	C<$prot> is a combination of C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_EXEC>,
		1647	C<IO::AIO::PROT_READ> and/or C<IO::AIO::PROT_WRITE>,
		1648
		1649	C<$flags> can be a combination of C<IO::AIO::MAP_SHARED> or
		1650	C<IO::AIO::MAP_PRIVATE>, or a number of system-specific flags (when
		1651	not available, the are defined as 0): C<IO::AIO::MAP_ANONYMOUS>
		1652	(which is set to C<MAP_ANON> if your system only provides this
		1653	constant), C<IO::AIO::MAP_HUGETLB>, C<IO::AIO::MAP_LOCKED>,
		1654	C<IO::AIO::MAP_NORESERVE>, C<IO::AIO::MAP_POPULATE> or
		1655	C<IO::AIO::MAP_NONBLOCK>
		1656
		1657	If C<$fh> is C<undef>, then a file descriptor of C<-1> is passed.
		1658
		1659	C<$offset> is the offset from the start of the file - it generally must be
		1660	a multiple of C<IO::AIO::PAGESIZE> and defaults to C<0>.
		1661
		1662	Example:
		1663
		1664	use Digest::MD5;
		1665	use IO::AIO;
		1666
		1667	open my $fh, "<verybigfile"
		1668	or die "$!";
		1669
		1670	IO::AIO::mmap my $data, -s $fh, IO::AIO::PROT_READ, IO::AIO::MAP_SHARED, $fh
		1671	or die "verybigfile: $!";
		1672
		1673	my $fast_md5 = md5 $data;
		1674
		1675	=item IO::AIO::munmap $scalar
		1676
		1677	Removes a previous mmap and undefines the C<$scalar>.
		1678
		1679	=item IO::AIO::munlock $scalar, $offset = 0, $length = undef
		1680
		1681	Calls the C<munlock> function, undoing the effects of a previous
		1682	C<aio_mlock> call (see its description for details).
		1683
		1684	=item IO::AIO::munlockall
		1685
		1686	Calls the C<munlockall> function.
		1687
		1688	On systems that do not implement C<munlockall>, this function returns
		1689	ENOSYS, otherwise the return value of C<munlockall>.
		1690
		1691	=back
		1692
1184	=cut	1693	=cut
1185		1694
1186	# support function to convert a fd into a perl filehandle
1187	sub _fd2fh {
1188	return undef if $_[0] < 0;
1189
1190	# try to generate nice filehandles
1191	my $sym = "IO::AIO::fd#$_[0]";
1192	local *$sym;
1193
1194	open *$sym, "+<&=$_[0]" # usually works under any unix
1195	or open *$sym, "<&=$_[0]" # cygwin needs this
1196	or open *$sym, ">&=$_[0]" # or this
1197	or return undef;
1198
1199	*$sym
1200	}
1201
1202	min_parallel 8;	1695	min_parallel 8;
1203		1696
1204	END { flush }	1697	END { flush }
1205		1698
1206	1;	1699	1;
		1700
		1701	=head1 EVENT LOOP INTEGRATION
		1702
		1703	It is recommended to use L<AnyEvent::AIO> to integrate IO::AIO
		1704	automatically into many event loops:
		1705
		1706	# AnyEvent integration (EV, Event, Glib, Tk, POE, urxvt, pureperl...)
		1707	use AnyEvent::AIO;
		1708
		1709	You can also integrate IO::AIO manually into many event loops, here are
		1710	some examples of how to do this:
		1711
		1712	# EV integration
		1713	my $aio_w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb;
		1714
		1715	# Event integration
		1716	Event->io (fd => IO::AIO::poll_fileno,
		1717	poll => 'r',
		1718	cb => \&IO::AIO::poll_cb);
		1719
		1720	# Glib/Gtk2 integration
		1721	add_watch Glib::IO IO::AIO::poll_fileno,
		1722	in => sub { IO::AIO::poll_cb; 1 };
		1723
		1724	# Tk integration
		1725	Tk::Event::IO->fileevent (IO::AIO::poll_fileno, "",
		1726	readable => \&IO::AIO::poll_cb);
		1727
		1728	# Danga::Socket integration
		1729	Danga::Socket->AddOtherFds (IO::AIO::poll_fileno =>
		1730	\&IO::AIO::poll_cb);
1207		1731
1208	=head2 FORK BEHAVIOUR	1732	=head2 FORK BEHAVIOUR
1209		1733
1210	This module should do "the right thing" when the process using it forks:	1734	This module should do "the right thing" when the process using it forks:
1211		1735
…		…
1229	bytes of memory. In addition, stat requests need a stat buffer (possibly	1753	bytes of memory. In addition, stat requests need a stat buffer (possibly
1230	a few hundred bytes), readdir requires a result buffer and so on. Perl	1754	a few hundred bytes), readdir requires a result buffer and so on. Perl
1231	scalars and other data passed into aio requests will also be locked and	1755	scalars and other data passed into aio requests will also be locked and
1232	will consume memory till the request has entered the done state.	1756	will consume memory till the request has entered the done state.
1233		1757
1234	This is now awfully much, so queuing lots of requests is not usually a	1758	This is not awfully much, so queuing lots of requests is not usually a
1235	problem.	1759	problem.
1236		1760
1237	Per-thread usage:	1761	Per-thread usage:
1238		1762
1239	In the execution phase, some aio requests require more memory for	1763	In the execution phase, some aio requests require more memory for
…		…
1244		1768
1245	Known bugs will be fixed in the next release.	1769	Known bugs will be fixed in the next release.
1246		1770
1247	=head1 SEE ALSO	1771	=head1 SEE ALSO
1248		1772
1249	L<Coro::AIO>.	1773	L<AnyEvent::AIO> for easy integration into event loops, L<Coro::AIO> for a
		1774	more natural syntax.
1250		1775
1251	=head1 AUTHOR	1776	=head1 AUTHOR
1252		1777
1253	Marc Lehmann <schmorp@schmorp.de>	1778	Marc Lehmann <schmorp@schmorp.de>
1254	http://home.schmorp.de/	1779	http://home.schmorp.de/

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