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Revision 1.103 by root, Tue Jan 23 22:57:34 2007 UTC vs.
Revision 1.181 by root, Tue May 4 21:14:01 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 = '3.65';
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_statvfs);
		183
201	our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice aio_block));	184	our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice));
202	our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush	185	our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush
203	min_parallel max_parallel max_idle	186	min_parallel max_parallel max_idle
204	nreqs nready npending nthreads	187	nreqs nready npending nthreads
205	max_poll_time max_poll_reqs);	188	max_poll_time max_poll_reqs
		189	sendfile fadvise);
		190
		191	push @AIO_REQ, qw(aio_busy); # not exported
206		192
207	@IO::AIO::GRP::ISA = 'IO::AIO::REQ';	193	@IO::AIO::GRP::ISA = 'IO::AIO::REQ';
208		194
209	require XSLoader;	195	require XSLoader;
210	XSLoader::load ("IO::AIO", $VERSION);	196	XSLoader::load ("IO::AIO", $VERSION);
211	}	197	}
212		198
213	=head1 FUNCTIONS	199	=head1 FUNCTIONS
		200
		201	=head2 QUICK OVERVIEW
		202
		203	This section simply lists the prototypes of the most important functions
		204	for quick reference. See the following sections for function-by-function
		205	documentation.
		206
		207	aio_open $pathname, $flags, $mode, $callback->($fh)
		208	aio_close $fh, $callback->($status)
		209	aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
		210	aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
		211	aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval)
		212	aio_readahead $fh,$offset,$length, $callback->($retval)
		213	aio_stat $fh_or_path, $callback->($status)
		214	aio_lstat $fh, $callback->($status)
		215	aio_statvfs $fh_or_path, $callback->($statvfs)
		216	aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
		217	aio_chown $fh_or_path, $uid, $gid, $callback->($status)
		218	aio_truncate $fh_or_path, $offset, $callback->($status)
		219	aio_chmod $fh_or_path, $mode, $callback->($status)
		220	aio_unlink $pathname, $callback->($status)
		221	aio_mknod $path, $mode, $dev, $callback->($status)
		222	aio_link $srcpath, $dstpath, $callback->($status)
		223	aio_symlink $srcpath, $dstpath, $callback->($status)
		224	aio_readlink $path, $callback->($link)
		225	aio_rename $srcpath, $dstpath, $callback->($status)
		226	aio_mkdir $pathname, $mode, $callback->($status)
		227	aio_rmdir $pathname, $callback->($status)
		228	aio_readdir $pathname, $callback->($entries)
		229	aio_readdirx $pathname, $flags, $callback->($entries, $flags)
		230	IO::AIO::READDIR_DENTS IO::AIO::READDIR_DIRS_FIRST
		231	IO::AIO::READDIR_STAT_ORDER IO::AIO::READDIR_FOUND_UNKNOWN
		232	aio_load $path, $data, $callback->($status)
		233	aio_copy $srcpath, $dstpath, $callback->($status)
		234	aio_move $srcpath, $dstpath, $callback->($status)
		235	aio_scandir $path, $maxreq, $callback->($dirs, $nondirs)
		236	aio_rmtree $path, $callback->($status)
		237	aio_sync $callback->($status)
		238	aio_fsync $fh, $callback->($status)
		239	aio_fdatasync $fh, $callback->($status)
		240	aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status)
		241	aio_pathsync $path, $callback->($status)
		242	aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
		243	aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
		244	aio_group $callback->(...)
		245	aio_nop $callback->()
		246
		247	$prev_pri = aioreq_pri [$pri]
		248	aioreq_nice $pri_adjust
		249
		250	IO::AIO::poll_wait
		251	IO::AIO::poll_cb
		252	IO::AIO::poll
		253	IO::AIO::flush
		254	IO::AIO::max_poll_reqs $nreqs
		255	IO::AIO::max_poll_time $seconds
		256	IO::AIO::min_parallel $nthreads
		257	IO::AIO::max_parallel $nthreads
		258	IO::AIO::max_idle $nthreads
		259	IO::AIO::max_outstanding $maxreqs
		260	IO::AIO::nreqs
		261	IO::AIO::nready
		262	IO::AIO::npending
		263
		264	IO::AIO::sendfile $ofh, $ifh, $offset, $count
		265	IO::AIO::fadvise $fh, $offset, $len, $advice
		266	IO::AIO::mlockall $flags
		267	IO::AIO::munlockall
214		268
215	=head2 AIO REQUEST FUNCTIONS	269	=head2 AIO REQUEST FUNCTIONS
216		270
217	All the C<aio_*> calls are more or less thin wrappers around the syscall	271	All the C<aio_*> calls are more or less thin wrappers around the syscall
218	with the same name (sans C<aio_>). The arguments are similar or identical,	272	with the same name (sans C<aio_>). The arguments are similar or identical,
219	and they all accept an additional (and optional) C<$callback> argument	273	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	274	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	275	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	276	perl, which usually delivers "false") as its sole argument after the given
223	syscall has been executed asynchronously.	277	syscall has been executed asynchronously.
224		278
225	All functions expecting a filehandle keep a copy of the filehandle	279	All functions expecting a filehandle keep a copy of the filehandle
226	internally until the request has finished.	280	internally until the request has finished.
227		281
…		…
241	your pathnames to the locale (or other) encoding in effect in the user	295	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)	296	environment, d) use Glib::filename_from_unicode on unicode filenames or e)
243	use something else to ensure your scalar has the correct contents.	297	use something else to ensure your scalar has the correct contents.
244		298
245	This works, btw. independent of the internal UTF-8 bit, which IO::AIO	299	This works, btw. independent of the internal UTF-8 bit, which IO::AIO
246	handles correctly wether it is set or not.	300	handles correctly whether it is set or not.
247		301
248	=over 4	302	=over 4
249		303
250	=item $prev_pri = aioreq_pri [$pri]	304	=item $prev_pri = aioreq_pri [$pri]
251		305
…		…
271	aio_read $_[0], ..., sub {	325	aio_read $_[0], ..., sub {
272	...	326	...
273	};	327	};
274	};	328	};
275		329
		330
276	=item aioreq_nice $pri_adjust	331	=item aioreq_nice $pri_adjust
277		332
278	Similar to C<aioreq_pri>, but subtracts the given value from the current	333	Similar to C<aioreq_pri>, but subtracts the given value from the current
279	priority, so the effect is cumulative.	334	priority, so the effect is cumulative.
		335
280		336
281	=item aio_open $pathname, $flags, $mode, $callback->($fh)	337	=item aio_open $pathname, $flags, $mode, $callback->($fh)
282		338
283	Asynchronously open or create a file and call the callback with a newly	339	Asynchronously open or create a file and call the callback with a newly
284	created filehandle for the file.	340	created filehandle for the file.
…		…
296	by the umask in effect then the request is being executed, so better never	352	by the umask in effect then the request is being executed, so better never
297	change the umask.	353	change the umask.
298		354
299	Example:	355	Example:
300		356
301	aio_open "/etc/passwd", O_RDONLY, 0, sub {	357	aio_open "/etc/passwd", IO::AIO::O_RDONLY, 0, sub {
302	if ($_[0]) {	358	if ($_[0]) {
303	print "open successful, fh is $_[0]\n";	359	print "open successful, fh is $_[0]\n";
304	...	360	...
305	} else {	361	} else {
306	die "open failed: $!\n";	362	die "open failed: $!\n";
307	}	363	}
308	};	364	};
309		365
		366
310	=item aio_close $fh, $callback->($status)	367	=item aio_close $fh, $callback->($status)
311		368
312	Asynchronously close a file and call the callback with the result	369	Asynchronously close a file and call the callback with the result
313	code. I<WARNING:> although accepted, you should not pass in a perl	370	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		371
318	This is supposed to be a bug in the API, so that might change. It's	372	Unfortunately, you can't do this to perl. Perl I<insists> very strongly on
319	therefore best to avoid this function.	373	closing the file descriptor associated with the filehandle itself.
		374
		375	Therefore, C<aio_close> will not close the filehandle - instead it will
		376	use dup2 to overwrite the file descriptor with the write-end of a pipe
		377	(the pipe fd will be created on demand and will be cached).
		378
		379	Or in other words: the file descriptor will be closed, but it will not be
		380	free for reuse until the perl filehandle is closed.
		381
		382	=cut
320		383
321	=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)	384	=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
322		385
323	=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)	386	=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
324		387
325	Reads or writes C<length> bytes from the specified C<fh> and C<offset>	388	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	389	C<$offset> into the scalar given by C<$data> and offset C<$dataoffset>
327	callback without the actual number of bytes read (or -1 on error, just	390	and calls the callback without the actual number of bytes read (or -1 on
328	like the syscall).	391	error, just like the syscall).
		392
		393	C<aio_read> will, like C<sysread>, shrink or grow the C<$data> scalar to
		394	offset plus the actual number of bytes read.
		395
		396	If C<$offset> is undefined, then the current file descriptor offset will
		397	be used (and updated), otherwise the file descriptor offset will not be
		398	changed by these calls.
		399
		400	If C<$length> is undefined in C<aio_write>, use the remaining length of
		401	C<$data>.
		402
		403	If C<$dataoffset> is less than zero, it will be counted from the end of
		404	C<$data>.
329		405
330	The C<$data> scalar I<MUST NOT> be modified in any way while the request	406	The C<$data> scalar I<MUST NOT> be modified in any way while the request
331	is outstanding. Modifying it can result in segfaults or WW3 (if the	407	is outstanding. Modifying it can result in segfaults or World War III (if
332	necessary/optional hardware is installed).	408	the necessary/optional hardware is installed).
333		409
334	Example: Read 15 bytes at offset 7 into scalar C<$buffer>, starting at	410	Example: Read 15 bytes at offset 7 into scalar C<$buffer>, starting at
335	offset C<0> within the scalar:	411	offset C<0> within the scalar:
336		412
337	aio_read $fh, 7, 15, $buffer, 0, sub {	413	aio_read $fh, 7, 15, $buffer, 0, sub {
338	$_[0] > 0 or die "read error: $!";	414	$_[0] > 0 or die "read error: $!";
339	print "read $_[0] bytes: <$buffer>\n";	415	print "read $_[0] bytes: <$buffer>\n";
340	};	416	};
		417
341		418
342	=item aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval)	419	=item aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval)
343		420
344	Tries to copy C<$length> bytes from C<$in_fh> to C<$out_fh>. It starts	421	Tries to copy C<$length> bytes from C<$in_fh> to C<$out_fh>. It starts
345	reading at byte offset C<$in_offset>, and starts writing at the current	422	reading at byte offset C<$in_offset>, and starts writing at the current
…		…
347	than one C<aio_sendfile> per C<$out_fh>, as they will interfere with each	424	than one C<aio_sendfile> per C<$out_fh>, as they will interfere with each
348	other.	425	other.
349		426
350	This call tries to make use of a native C<sendfile> syscall to provide	427	This call tries to make use of a native C<sendfile> syscall to provide
351	zero-copy operation. For this to work, C<$out_fh> should refer to a	428	zero-copy operation. For this to work, C<$out_fh> should refer to a
352	socket, and C<$in_fh> should refer to mmap'able file.	429	socket, and C<$in_fh> should refer to an mmap'able file.
353		430
354	If the native sendfile call fails or is not implemented, it will be	431	If a native sendfile cannot be found or it fails with C<ENOSYS>,
		432	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	433	it will be emulated, so you can call C<aio_sendfile> on any type of
356	regardless of the limitations of the operating system.	434	filehandle regardless of the limitations of the operating system.
357		435
358	Please note, however, that C<aio_sendfile> can read more bytes from	436	Please note, however, that C<aio_sendfile> can read more bytes from
359	C<$in_fh> than are written, and there is no way to find out how many	437	C<$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	438	bytes have been read from C<aio_sendfile> alone, as C<aio_sendfile> only
361	provides the number of bytes written to C<$out_fh>. Only if the result	439	provides the number of bytes written to C<$out_fh>. Only if the result
362	value equals C<$length> one can assume that C<$length> bytes have been	440	value equals C<$length> one can assume that C<$length> bytes have been
363	read.	441	read.
		442
364		443
365	=item aio_readahead $fh,$offset,$length, $callback->($retval)	444	=item aio_readahead $fh,$offset,$length, $callback->($retval)
366		445
367	C<aio_readahead> populates the page cache with data from a file so that	446	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<$offset>	447	subsequent reads from that file will not block on disk I/O. The C<$offset>
…		…
374	file. The current file offset of the file is left unchanged.	453	file. The current file offset of the file is left unchanged.
375		454
376	If that syscall doesn't exist (likely if your OS isn't Linux) it will be	455	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.	456	emulated by simply reading the data, which would have a similar effect.
378		457
		458
379	=item aio_stat $fh_or_path, $callback->($status)	459	=item aio_stat $fh_or_path, $callback->($status)
380		460
381	=item aio_lstat $fh, $callback->($status)	461	=item aio_lstat $fh, $callback->($status)
382		462
383	Works like perl's C<stat> or C<lstat> in void context. The callback will	463	Works like perl's C<stat> or C<lstat> in void context. The callback will
…		…
396	aio_stat "/etc/passwd", sub {	476	aio_stat "/etc/passwd", sub {
397	$_[0] and die "stat failed: $!";	477	$_[0] and die "stat failed: $!";
398	print "size is ", -s _, "\n";	478	print "size is ", -s _, "\n";
399	};	479	};
400		480
		481
		482	=item aio_statvfs $fh_or_path, $callback->($statvfs)
		483
		484	Works like the POSIX C<statvfs> or C<fstatvfs> syscalls, depending on
		485	whether a file handle or path was passed.
		486
		487	On success, the callback is passed a hash reference with the following
		488	members: C<bsize>, C<frsize>, C<blocks>, C<bfree>, C<bavail>, C<files>,
		489	C<ffree>, C<favail>, C<fsid>, C<flag> and C<namemax>. On failure, C<undef>
		490	is passed.
		491
		492	The following POSIX IO::AIO::ST_* constants are defined: C<ST_RDONLY> and
		493	C<ST_NOSUID>.
		494
		495	The following non-POSIX IO::AIO::ST_* flag masks are defined to
		496	their correct value when available, or to C<0> on systems that do
		497	not support them: C<ST_NODEV>, C<ST_NOEXEC>, C<ST_SYNCHRONOUS>,
		498	C<ST_MANDLOCK>, C<ST_WRITE>, C<ST_APPEND>, C<ST_IMMUTABLE>, C<ST_NOATIME>,
		499	C<ST_NODIRATIME> and C<ST_RELATIME>.
		500
		501	Example: stat C</wd> and dump out the data if successful.
		502
		503	aio_statvfs "/wd", sub {
		504	my $f = $_[0]
		505	or die "statvfs: $!";
		506
		507	use Data::Dumper;
		508	say Dumper $f;
		509	};
		510
		511	# result:
		512	{
		513	bsize => 1024,
		514	bfree => 4333064312,
		515	blocks => 10253828096,
		516	files => 2050765568,
		517	flag => 4096,
		518	favail => 2042092649,
		519	bavail => 4333064312,
		520	ffree => 2042092649,
		521	namemax => 255,
		522	frsize => 1024,
		523	fsid => 1810
		524	}
		525
		526
		527	=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
		528
		529	Works like perl's C<utime> function (including the special case of $atime
		530	and $mtime being undef). Fractional times are supported if the underlying
		531	syscalls support them.
		532
		533	When called with a pathname, uses utimes(2) if available, otherwise
		534	utime(2). If called on a file descriptor, uses futimes(2) if available,
		535	otherwise returns ENOSYS, so this is not portable.
		536
		537	Examples:
		538
		539	# set atime and mtime to current time (basically touch(1)):
		540	aio_utime "path", undef, undef;
		541	# set atime to current time and mtime to beginning of the epoch:
		542	aio_utime "path", time, undef; # undef==0
		543
		544
		545	=item aio_chown $fh_or_path, $uid, $gid, $callback->($status)
		546
		547	Works like perl's C<chown> function, except that C<undef> for either $uid
		548	or $gid is being interpreted as "do not change" (but -1 can also be used).
		549
		550	Examples:
		551
		552	# same as "chown root path" in the shell:
		553	aio_chown "path", 0, -1;
		554	# same as above:
		555	aio_chown "path", 0, undef;
		556
		557
		558	=item aio_truncate $fh_or_path, $offset, $callback->($status)
		559
		560	Works like truncate(2) or ftruncate(2).
		561
		562
		563	=item aio_chmod $fh_or_path, $mode, $callback->($status)
		564
		565	Works like perl's C<chmod> function.
		566
		567
401	=item aio_unlink $pathname, $callback->($status)	568	=item aio_unlink $pathname, $callback->($status)
402		569
403	Asynchronously unlink (delete) a file and call the callback with the	570	Asynchronously unlink (delete) a file and call the callback with the
404	result code.	571	result code.
405		572
		573
406	=item aio_mknod $path, $mode, $dev, $callback->($status)	574	=item aio_mknod $path, $mode, $dev, $callback->($status)
407		575
408	[EXPERIMENTAL]	576	[EXPERIMENTAL]
409		577
410	Asynchronously create a device node (or fifo). See mknod(2).	578	Asynchronously create a device node (or fifo). See mknod(2).
411		579
412	The only (POSIX-) portable way of calling this function is:	580	The only (POSIX-) portable way of calling this function is:
413		581
414	aio_mknod $path, IO::AIO::S_IFIFO | $mode, 0, sub { ...	582	aio_mknod $path, IO::AIO::S_IFIFO | $mode, 0, sub { ...
		583
415		584
416	=item aio_link $srcpath, $dstpath, $callback->($status)	585	=item aio_link $srcpath, $dstpath, $callback->($status)
417		586
418	Asynchronously create a new link to the existing object at C<$srcpath> at	587	Asynchronously create a new link to the existing object at C<$srcpath> at
419	the path C<$dstpath> and call the callback with the result code.	588	the path C<$dstpath> and call the callback with the result code.
420		589
		590
421	=item aio_symlink $srcpath, $dstpath, $callback->($status)	591	=item aio_symlink $srcpath, $dstpath, $callback->($status)
422		592
423	Asynchronously create a new symbolic link to the existing object at C<$srcpath> at	593	Asynchronously create a new symbolic link to the existing object at C<$srcpath> at
424	the path C<$dstpath> and call the callback with the result code.	594	the path C<$dstpath> and call the callback with the result code.
		595
425		596
426	=item aio_readlink $path, $callback->($link)	597	=item aio_readlink $path, $callback->($link)
427		598
428	Asynchronously read the symlink specified by C<$path> and pass it to	599	Asynchronously read the symlink specified by C<$path> and pass it to
429	the callback. If an error occurs, nothing or undef gets passed to the	600	the callback. If an error occurs, nothing or undef gets passed to the
430	callback.	601	callback.
431		602
		603
432	=item aio_rename $srcpath, $dstpath, $callback->($status)	604	=item aio_rename $srcpath, $dstpath, $callback->($status)
433		605
434	Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as	606	Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as
435	rename(2) and call the callback with the result code.	607	rename(2) and call the callback with the result code.
		608
436		609
437	=item aio_mkdir $pathname, $mode, $callback->($status)	610	=item aio_mkdir $pathname, $mode, $callback->($status)
438		611
439	Asynchronously mkdir (create) a directory and call the callback with	612	Asynchronously mkdir (create) a directory and call the callback with
440	the result code. C<$mode> will be modified by the umask at the time the	613	the result code. C<$mode> will be modified by the umask at the time the
441	request is executed, so do not change your umask.	614	request is executed, so do not change your umask.
442		615
		616
443	=item aio_rmdir $pathname, $callback->($status)	617	=item aio_rmdir $pathname, $callback->($status)
444		618
445	Asynchronously rmdir (delete) a directory and call the callback with the	619	Asynchronously rmdir (delete) a directory and call the callback with the
446	result code.	620	result code.
		621
447		622
448	=item aio_readdir $pathname, $callback->($entries)	623	=item aio_readdir $pathname, $callback->($entries)
449		624
450	Unlike the POSIX call of the same name, C<aio_readdir> reads an entire	625	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	626	directory (i.e. opendir + readdir + closedir). The entries will not be
452	sorted, and will B<NOT> include the C<.> and C<..> entries.	627	sorted, and will B<NOT> include the C<.> and C<..> entries.
453		628
454	The callback a single argument which is either C<undef> or an array-ref	629	The callback is passed a single argument which is either C<undef> or an
455	with the filenames.	630	array-ref with the filenames.
		631
		632
		633	=item aio_readdirx $pathname, $flags, $callback->($entries, $flags)
		634
		635	Quite similar to C<aio_readdir>, but the C<$flags> argument allows to tune
		636	behaviour and output format. In case of an error, C<$entries> will be
		637	C<undef>.
		638
		639	The flags are a combination of the following constants, ORed together (the
		640	flags will also be passed to the callback, possibly modified):
		641
		642	=over 4
		643
		644	=item IO::AIO::READDIR_DENTS
		645
		646	When this flag is off, then the callback gets an arrayref with of names
		647	only (as with C<aio_readdir>), otherwise it gets an arrayref with
		648	C<[$name, $type, $inode]> arrayrefs, each describing a single directory
		649	entry in more detail.
		650
		651	C<$name> is the name of the entry.
		652
		653	C<$type> is one of the C<IO::AIO::DT_xxx> constants:
		654
		655	C<IO::AIO::DT_UNKNOWN>, C<IO::AIO::DT_FIFO>, C<IO::AIO::DT_CHR>, C<IO::AIO::DT_DIR>,
		656	C<IO::AIO::DT_BLK>, C<IO::AIO::DT_REG>, C<IO::AIO::DT_LNK>, C<IO::AIO::DT_SOCK>,
		657	C<IO::AIO::DT_WHT>.
		658
		659	C<IO::AIO::DT_UNKNOWN> means just that: readdir does not know. If you need to
		660	know, you have to run stat yourself. Also, for speed reasons, the C<$type>
		661	scalars are read-only: you can not modify them.
		662
		663	C<$inode> is the inode number (which might not be exact on systems with 64
		664	bit inode numbers and 32 bit perls). This field has unspecified content on
		665	systems that do not deliver the inode information.
		666
		667	=item IO::AIO::READDIR_DIRS_FIRST
		668
		669	When this flag is set, then the names will be returned in an order where
		670	likely directories come first. This is useful when you need to quickly
		671	find directories, or you want to find all directories while avoiding to
		672	stat() each entry.
		673
		674	If the system returns type information in readdir, then this is used
		675	to find directories directly. Otherwise, likely directories are files
		676	beginning with ".", or otherwise files with no dots, of which files with
		677	short names are tried first.
		678
		679	=item IO::AIO::READDIR_STAT_ORDER
		680
		681	When this flag is set, then the names will be returned in an order
		682	suitable for stat()'ing each one. That is, when you plan to stat()
		683	all files in the given directory, then the returned order will likely
		684	be fastest.
		685
		686	If both this flag and C<IO::AIO::READDIR_DIRS_FIRST> are specified, then
		687	the likely dirs come first, resulting in a less optimal stat order.
		688
		689	=item IO::AIO::READDIR_FOUND_UNKNOWN
		690
		691	This flag should not be set when calling C<aio_readdirx>. Instead, it
		692	is being set by C<aio_readdirx>, when any of the C<$type>'s found were
		693	C<IO::AIO::DT_UNKNOWN>. The absense of this flag therefore indicates that all
		694	C<$type>'s are known, which can be used to speed up some algorithms.
		695
		696	=back
		697
456		698
457	=item aio_load $path, $data, $callback->($status)	699	=item aio_load $path, $data, $callback->($status)
458		700
459	This is a composite request that tries to fully load the given file into	701	This is a composite request that tries to fully load the given file into
460	memory. Status is the same as with aio_read.	702	memory. Status is the same as with aio_read.
461		703
462	=cut	704	=cut
463		705
464	sub aio_load($$;$) {	706	sub aio_load($$;$) {
465	aio_block {
466	my ($path, undef, $cb) = @_;	707	my ($path, undef, $cb) = @_;
467	my $data = \$_[1];	708	my $data = \$_[1];
468		709
469	my $pri = aioreq_pri;	710	my $pri = aioreq_pri;
470	my $grp = aio_group $cb;	711	my $grp = aio_group $cb;
		712
		713	aioreq_pri $pri;
		714	add $grp aio_open $path, O_RDONLY, 0, sub {
		715	my $fh = shift
		716	or return $grp->result (-1);
471		717
472	aioreq_pri $pri;	718	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), $$data, 0, sub {	719	add $grp aio_read $fh, 0, (-s $fh), $$data, 0, sub {
479	$grp->result ($_[0]);	720	$grp->result ($_[0]);
480	};
481	};	721	};
482
483	$grp
484	}	722	};
		723
		724	$grp
485	}	725	}
486		726
487	=item aio_copy $srcpath, $dstpath, $callback->($status)	727	=item aio_copy $srcpath, $dstpath, $callback->($status)
488		728
489	Try to copy the I<file> (directories not supported as either source or	729	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	730	destination) from C<$srcpath> to C<$dstpath> and call the callback with
491	the C<0> (error) or C<-1> ok.	731	a status of C<0> (ok) or C<-1> (error, see C<$!>).
492		732
493	This is a composite request that it creates the destination file with	733	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	734	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	735	C<aio_sendfile>, followed by restoring atime, mtime, access mode and
496	uid/gid, in that order.	736	uid/gid, in that order.
497		737
498	If an error occurs, the partial destination file will be unlinked, if	738	If an error occurs, the partial destination file will be unlinked, if
…		…
500	errors are being ignored.	740	errors are being ignored.
501		741
502	=cut	742	=cut
503		743
504	sub aio_copy($$;$) {	744	sub aio_copy($$;$) {
505	aio_block {
506	my ($src, $dst, $cb) = @_;	745	my ($src, $dst, $cb) = @_;
507		746
508	my $pri = aioreq_pri;	747	my $pri = aioreq_pri;
509	my $grp = aio_group $cb;	748	my $grp = aio_group $cb;
510		749
511	aioreq_pri $pri;	750	aioreq_pri $pri;
512	add $grp aio_open $src, O_RDONLY, 0, sub {	751	add $grp aio_open $src, O_RDONLY, 0, sub {
513	if (my $src_fh = $_[0]) {	752	if (my $src_fh = $_[0]) {
514	my @stat = stat $src_fh;	753	my @stat = stat $src_fh; # hmm, might block over nfs?
515		754
516	aioreq_pri $pri;	755	aioreq_pri $pri;
517	add $grp aio_open $dst, O_CREAT | O_WRONLY | O_TRUNC, 0200, sub {	756	add $grp aio_open $dst, O_CREAT | O_WRONLY | O_TRUNC, 0200, sub {
518	if (my $dst_fh = $_[0]) {	757	if (my $dst_fh = $_[0]) {
519	aioreq_pri $pri;	758	aioreq_pri $pri;
520	add $grp aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub {	759	add $grp aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub {
521	if ($_[0] == $stat[7]) {	760	if ($_[0] == $stat[7]) {
522	$grp->result (0);	761	$grp->result (0);
523	close $src_fh;	762	close $src_fh;
524		763
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 {	764	my $ch = sub {
531	$grp->result (-1);
532	close $src_fh;
533	close $dst_fh;
534
535	aioreq $pri;	765	aioreq_pri $pri;
		766	add $grp aio_chmod $dst_fh, $stat[2] & 07777, sub {
		767	aioreq_pri $pri;
		768	add $grp aio_chown $dst_fh, $stat[4], $stat[5], sub {
		769	aioreq_pri $pri;
536	add $grp aio_unlink $dst;	770	add $grp aio_close $dst_fh;
		771	}
		772	};
537	}	773	};
		774
		775	aioreq_pri $pri;
		776	add $grp aio_utime $dst_fh, $stat[8], $stat[9], sub {
		777	if ($_[0] < 0 && $! == ENOSYS) {
		778	aioreq_pri $pri;
		779	add $grp aio_utime $dst, $stat[8], $stat[9], $ch;
		780	} else {
		781	$ch->();
		782	}
		783	};
		784	} else {
		785	$grp->result (-1);
		786	close $src_fh;
		787	close $dst_fh;
		788
		789	aioreq $pri;
		790	add $grp aio_unlink $dst;
538	};	791	}
539	} else {
540	$grp->result (-1);
541	}	792	};
		793	} else {
		794	$grp->result (-1);
542	},	795	}
543
544	} else {
545	$grp->result (-1);
546	}	796	},
		797
		798	} else {
		799	$grp->result (-1);
547	};	800	}
548
549	$grp
550	}	801	};
		802
		803	$grp
551	}	804	}
552		805
553	=item aio_move $srcpath, $dstpath, $callback->($status)	806	=item aio_move $srcpath, $dstpath, $callback->($status)
554		807
555	Try to move the I<file> (directories not supported as either source or	808	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	809	destination) from C<$srcpath> to C<$dstpath> and call the callback with
557	the C<0> (error) or C<-1> ok.	810	a status of C<0> (ok) or C<-1> (error, see C<$!>).
558		811
559	This is a composite request that tries to rename(2) the file first. If	812	This is a composite request that tries to rename(2) the file first; if
560	rename files with C<EXDEV>, it copies the file with C<aio_copy> and, if	813	rename fails with C<EXDEV>, it copies the file with C<aio_copy> and, if
561	that is successful, unlinking the C<$srcpath>.	814	that is successful, unlinks the C<$srcpath>.
562		815
563	=cut	816	=cut
564		817
565	sub aio_move($$;$) {	818	sub aio_move($$;$) {
566	aio_block {
567	my ($src, $dst, $cb) = @_;	819	my ($src, $dst, $cb) = @_;
568		820
569	my $pri = aioreq_pri;	821	my $pri = aioreq_pri;
570	my $grp = aio_group $cb;	822	my $grp = aio_group $cb;
571		823
572	aioreq_pri $pri;	824	aioreq_pri $pri;
573	add $grp aio_rename $src, $dst, sub {	825	add $grp aio_rename $src, $dst, sub {
574	if ($_[0] && $! == EXDEV) {	826	if ($_[0] && $! == EXDEV) {
575	aioreq_pri $pri;	827	aioreq_pri $pri;
576	add $grp aio_copy $src, $dst, sub {	828	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]);	829	$grp->result ($_[0]);
		830
		831	if (!$_[0]) {
		832	aioreq_pri $pri;
		833	add $grp aio_unlink $src;
		834	}
586	}	835	};
		836	} else {
		837	$grp->result ($_[0]);
587	};	838	}
588
589	$grp
590	}	839	};
		840
		841	$grp
591	}	842	}
592		843
593	=item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs)	844	=item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs)
594		845
595	Scans a directory (similar to C<aio_readdir>) but additionally tries to	846	Scans a directory (similar to C<aio_readdir>) but additionally tries to
…		…
615		866
616	Implementation notes.	867	Implementation notes.
617		868
618	The C<aio_readdir> cannot be avoided, but C<stat()>'ing every entry can.	869	The C<aio_readdir> cannot be avoided, but C<stat()>'ing every entry can.
619		870
		871	If readdir returns file type information, then this is used directly to
		872	find directories.
		873
620	After reading the directory, the modification time, size etc. of the	874	Otherwise, after reading the directory, the modification time, size etc.
621	directory before and after the readdir is checked, and if they match (and	875	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	876	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	877	how many entries are directories (if >= 2). Otherwise, no knowledge of the
624	of subdirectories will be assumed.	878	number of subdirectories will be assumed.
625		879
626	Then entries will be sorted into likely directories (everything without	880	Then entries will be sorted into likely directories a non-initial dot
627	a non-initial dot currently) and likely non-directories (everything	881	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,	882	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	883	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	884	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	885	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	886	filesystems might detect the type of the entry without reading the inode
633	data (e.g. ext2fs filetype feature).	887	data (e.g. ext2fs filetype feature), even on systems that cannot return
		888	the filetype information on readdir.
634		889
635	If the known number of directories (link count - 2) has been reached, the	890	If the known number of directories (link count - 2) has been reached, the
636	rest of the entries is assumed to be non-directories.	891	rest of the entries is assumed to be non-directories.
637		892
638	This only works with certainty on POSIX (= UNIX) filesystems, which	893	This only works with certainty on POSIX (= UNIX) filesystems, which
…		…
643	directory counting heuristic.	898	directory counting heuristic.
644		899
645	=cut	900	=cut
646		901
647	sub aio_scandir($$;$) {	902	sub aio_scandir($$;$) {
648	aio_block {
649	my ($path, $maxreq, $cb) = @_;	903	my ($path, $maxreq, $cb) = @_;
650		904
651	my $pri = aioreq_pri;	905	my $pri = aioreq_pri;
652		906
653	my $grp = aio_group $cb;	907	my $grp = aio_group $cb;
654		908
655	$maxreq = 4 if $maxreq <= 0;	909	$maxreq = 4 if $maxreq <= 0;
656		910
657	# stat once	911	# stat once
		912	aioreq_pri $pri;
		913	add $grp aio_stat $path, sub {
		914	return $grp->result () if $_[0];
		915	my $now = time;
		916	my $hash1 = join ":", (stat _)[0,1,3,7,9];
		917
		918	# read the directory entries
658	aioreq_pri $pri;	919	aioreq_pri $pri;
659	add $grp aio_stat $path, sub {	920	add $grp aio_readdirx $path, READDIR_DIRS_FIRST, sub {
		921	my $entries = shift
660	return $grp->result () if $_[0];	922	or return $grp->result ();
661	my $now = time;
662	my $hash1 = join ":", (stat _)[0,1,3,7,9];
663		923
664	# read the directory entries	924	# stat the dir another time
665	aioreq_pri $pri;	925	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 {	926	add $grp aio_stat $path, sub {
673	my $hash2 = join ":", (stat _)[0,1,3,7,9];	927	my $hash2 = join ":", (stat _)[0,1,3,7,9];
674		928
675	my $ndirs;	929	my $ndirs;
676		930
677	# take the slow route if anything looks fishy	931	# take the slow route if anything looks fishy
678	if ($hash1 ne $hash2 or (stat _)[9] == $now) {	932	if ($hash1 ne $hash2 or (stat _)[9] == $now) {
679	$ndirs = -1;	933	$ndirs = -1;
680	} else {	934	} else {
681	# if nlink == 2, we are finished	935	# if nlink == 2, we are finished
682	# on non-posix-fs's, we rely on nlink < 2	936	# for non-posix-fs's, we rely on nlink < 2
683	$ndirs = (stat _)[3] - 2	937	$ndirs = (stat _)[3] - 2
684	or return $grp->result ([], $entries);	938	or return $grp->result ([], $entries);
685	}	939	}
686		940
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);	941	my (@dirs, @nondirs);
695		942
696	my $statgrp = add $grp aio_group sub {	943	my $statgrp = add $grp aio_group sub {
697	$grp->result (\@dirs, \@nondirs);	944	$grp->result (\@dirs, \@nondirs);
698	};	945	};
699		946
700	limit $statgrp $maxreq;	947	limit $statgrp $maxreq;
701	feed $statgrp sub {	948	feed $statgrp sub {
702	return unless @$entries;	949	return unless @$entries;
703	my $entry = pop @$entries;	950	my $entry = shift @$entries;
704		951
705	aioreq_pri $pri;	952	aioreq_pri $pri;
706	add $statgrp aio_stat "$path/$entry/.", sub {	953	add $statgrp aio_stat "$path/$entry/.", sub {
707	if ($_[0] < 0) {	954	if ($_[0] < 0) {
708	push @nondirs, $entry;	955	push @nondirs, $entry;
709	} else {	956	} else {
710	# need to check for real directory	957	# need to check for real directory
711	aioreq_pri $pri;	958	aioreq_pri $pri;
712	add $statgrp aio_lstat "$path/$entry", sub {	959	add $statgrp aio_lstat "$path/$entry", sub {
713	if (-d _) {	960	if (-d _) {
714	push @dirs, $entry;	961	push @dirs, $entry;
715		962
716	unless (--$ndirs) {	963	unless (--$ndirs) {
717	push @nondirs, @$entries;	964	push @nondirs, @$entries;
718	feed $statgrp;	965	feed $statgrp;
719	}
720	} else {
721	push @nondirs, $entry;
722	}	966	}
		967	} else {
		968	push @nondirs, $entry;
723	}	969	}
724	}	970	}
725	};	971	}
726	};	972	};
727	};	973	};
728	};	974	};
729	};	975	};
730
731	$grp
732	}	976	};
		977
		978	$grp
733	}	979	}
734		980
735	=item aio_rmtree $path, $callback->($status)	981	=item aio_rmtree $path, $callback->($status)
736		982
737	Delete a directory tree starting (and including) C<$path>, return the	983	Delete a directory tree starting (and including) C<$path>, return the
…		…
741		987
742	=cut	988	=cut
743		989
744	sub aio_rmtree;	990	sub aio_rmtree;
745	sub aio_rmtree($;$) {	991	sub aio_rmtree($;$) {
746	aio_block {
747	my ($path, $cb) = @_;	992	my ($path, $cb) = @_;
748		993
749	my $pri = aioreq_pri;	994	my $pri = aioreq_pri;
750	my $grp = aio_group $cb;	995	my $grp = aio_group $cb;
751		996
752	aioreq_pri $pri;	997	aioreq_pri $pri;
753	add $grp aio_scandir $path, 0, sub {	998	add $grp aio_scandir $path, 0, sub {
754	my ($dirs, $nondirs) = @_;	999	my ($dirs, $nondirs) = @_;
755		1000
756	my $dirgrp = aio_group sub {	1001	my $dirgrp = aio_group sub {
757	add $grp aio_rmdir $path, sub {	1002	add $grp aio_rmdir $path, sub {
758	$grp->result ($_[0]);	1003	$grp->result ($_[0]);
759	};
760	};	1004	};
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	};	1005	};
767		1006
768	$grp	1007	(aioreq_pri $pri), add $dirgrp aio_rmtree "$path/$_" for @$dirs;
		1008	(aioreq_pri $pri), add $dirgrp aio_unlink "$path/$_" for @$nondirs;
		1009
		1010	add $grp $dirgrp;
769	}	1011	};
		1012
		1013	$grp
770	}	1014	}
		1015
		1016	=item aio_sync $callback->($status)
		1017
		1018	Asynchronously call sync and call the callback when finished.
771		1019
772	=item aio_fsync $fh, $callback->($status)	1020	=item aio_fsync $fh, $callback->($status)
773		1021
774	Asynchronously call fsync on the given filehandle and call the callback	1022	Asynchronously call fsync on the given filehandle and call the callback
775	with the fsync result code.	1023	with the fsync result code.
…		…
779	Asynchronously call fdatasync on the given filehandle and call the	1027	Asynchronously call fdatasync on the given filehandle and call the
780	callback with the fdatasync result code.	1028	callback with the fdatasync result code.
781		1029
782	If this call isn't available because your OS lacks it or it couldn't be	1030	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.	1031	detected, it will be emulated by calling C<fsync> instead.
		1032
		1033	=item aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status)
		1034
		1035	Sync the data portion of the file specified by C<$offset> and C<$length>
		1036	to disk (but NOT the metadata), by calling the Linux-specific
		1037	sync_file_range call. If sync_file_range is not available or it returns
		1038	ENOSYS, then fdatasync or fsync is being substituted.
		1039
		1040	C<$flags> can be a combination of C<IO::AIO::SYNC_FILE_RANGE_WAIT_BEFORE>,
		1041	C<IO::AIO::SYNC_FILE_RANGE_WRITE> and
		1042	C<IO::AIO::SYNC_FILE_RANGE_WAIT_AFTER>: refer to the sync_file_range
		1043	manpage for details.
		1044
		1045	=item aio_pathsync $path, $callback->($status)
		1046
		1047	This request tries to open, fsync and close the given path. This is a
		1048	composite request intended to sync directories after directory operations
		1049	(E.g. rename). This might not work on all operating systems or have any
		1050	specific effect, but usually it makes sure that directory changes get
		1051	written to disc. It works for anything that can be opened for read-only,
		1052	not just directories.
		1053
		1054	Future versions of this function might fall back to other methods when
		1055	C<fsync> on the directory fails (such as calling C<sync>).
		1056
		1057	Passes C<0> when everything went ok, and C<-1> on error.
		1058
		1059	=cut
		1060
		1061	sub aio_pathsync($;$) {
		1062	my ($path, $cb) = @_;
		1063
		1064	my $pri = aioreq_pri;
		1065	my $grp = aio_group $cb;
		1066
		1067	aioreq_pri $pri;
		1068	add $grp aio_open $path, O_RDONLY, 0, sub {
		1069	my ($fh) = @_;
		1070	if ($fh) {
		1071	aioreq_pri $pri;
		1072	add $grp aio_fsync $fh, sub {
		1073	$grp->result ($_[0]);
		1074
		1075	aioreq_pri $pri;
		1076	add $grp aio_close $fh;
		1077	};
		1078	} else {
		1079	$grp->result (-1);
		1080	}
		1081	};
		1082
		1083	$grp
		1084	}
		1085
		1086	=item aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
		1087
		1088	This is a rather advanced IO::AIO call, which only works on mmap(2)ed
		1089	scalars (see the C<IO::AIO::mmap> function, although it also works on data
		1090	scalars managed by the L<Sys::Mmap> or L<Mmap> modules, note that the
		1091	scalar must only be modified in-place while an aio operation is pending on
		1092	it).
		1093
		1094	It calls the C<msync> function of your OS, if available, with the memory
		1095	area starting at C<$offset> in the string and ending C<$length> bytes
		1096	later. If C<$length> is negative, counts from the end, and if C<$length>
		1097	is C<undef>, then it goes till the end of the string. The flags can be
		1098	a combination of C<IO::AIO::MS_ASYNC>, C<IO::AIO::MS_INVALIDATE> and
		1099	C<IO::AIO::MS_SYNC>.
		1100
		1101	=item aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
		1102
		1103	This is a rather advanced IO::AIO call, which works best on mmap(2)ed
		1104	scalars.
		1105
		1106	It touches (reads or writes) all memory pages in the specified
		1107	range inside the scalar. All caveats and parameters are the same
		1108	as for C<aio_msync>, above, except for flags, which must be either
		1109	C<0> (which reads all pages and ensures they are instantiated) or
		1110	C<IO::AIO::MT_MODIFY>, which modifies the memory page s(by reading and
		1111	writing an octet from it, which dirties the page).
784		1112
785	=item aio_group $callback->(...)	1113	=item aio_group $callback->(...)
786		1114
787	This is a very special aio request: Instead of doing something, it is a	1115	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	1116	container for other aio requests, which is useful if you want to bundle
…		…
838	=item cancel $req	1166	=item cancel $req
839		1167
840	Cancels the request, if possible. Has the effect of skipping execution	1168	Cancels the request, if possible. Has the effect of skipping execution
841	when entering the B<execute> state and skipping calling the callback when	1169	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	1170	entering the the B<result> state, but will leave the request otherwise
843	untouched. That means that requests that currently execute will not be	1171	untouched (with the exception of readdir). That means that requests that
844	stopped and resources held by the request will not be freed prematurely.	1172	currently execute will not be stopped and resources held by the request
		1173	will not be freed prematurely.
845		1174
846	=item cb $req $callback->(...)	1175	=item cb $req $callback->(...)
847		1176
848	Replace (or simply set) the callback registered to the request.	1177	Replace (or simply set) the callback registered to the request.
849		1178
…		…
900	Their lifetime, simplified, looks like this: when they are empty, they	1229	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	1230	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	1231	C<done> state, they will also finish. Otherwise they will continue to
903	exist.	1232	exist.
904		1233
905	That means after creating a group you have some time to add requests. And	1234	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	1235	(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	1236	the C<poll_cb>). And in the callbacks of those requests, you can add
908	itself finish.	1237	further requests to the group. And only when all those requests have
		1238	finished will the the group itself finish.
909		1239
910	=over 4	1240	=over 4
911		1241
912	=item add $grp ...	1242	=item add $grp ...
913		1243
…		…
922	=item $grp->cancel_subs	1252	=item $grp->cancel_subs
923		1253
924	Cancel all subrequests and clears any feeder, but not the group request	1254	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.	1255	itself. Useful when you queued a lot of events but got a result early.
926		1256
		1257	The group request will finish normally (you cannot add requests to the
		1258	group).
		1259
927	=item $grp->result (...)	1260	=item $grp->result (...)
928		1261
929	Set the result value(s) that will be passed to the group callback when all	1262	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	1263	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,	1264	of errno (just like calling C<errno> without an error number). By default,
932	no argument will be passed and errno is zero.	1265	no argument will be passed and errno is zero.
933		1266
934	=item $grp->errno ([$errno])	1267	=item $grp->errno ([$errno])
935		1268
…		…
946	=item feed $grp $callback->($grp)	1279	=item feed $grp $callback->($grp)
947		1280
948	Sets a feeder/generator on this group: every group can have an attached	1281	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,	1282	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,	1283	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	1284	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>	1285	C<aio_scandir> might generate hundreds of thousands C<aio_stat> requests,
953	requests, delaying any later requests for a long time.	1286	delaying any later requests for a long time.
954		1287
955	To avoid this, and allow incremental generation of requests, you can	1288	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	1289	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>,	1290	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	1291	below) requests active in the group itself and is expected to queue more
…		…
962	not impose any limits).	1295	not impose any limits).
963		1296
964	If the feed does not queue more requests when called, it will be	1297	If the feed does not queue more requests when called, it will be
965	automatically removed from the group.	1298	automatically removed from the group.
966		1299
967	If the feed limit is C<0>, it will be set to C<2> automatically.	1300	If the feed limit is C<0> when this method is called, it will be set to
		1301	C<2> automatically.
968		1302
969	Example:	1303	Example:
970		1304
971	# stat all files in @files, but only ever use four aio requests concurrently:	1305	# stat all files in @files, but only ever use four aio requests concurrently:
972		1306
…		…
984	Sets the feeder limit for the group: The feeder will be called whenever	1318	Sets the feeder limit for the group: The feeder will be called whenever
985	the group contains less than this many requests.	1319	the group contains less than this many requests.
986		1320
987	Setting the limit to C<0> will pause the feeding process.	1321	Setting the limit to C<0> will pause the feeding process.
988		1322
		1323	The default value for the limit is C<0>, but note that setting a feeder
		1324	automatically bumps it up to C<2>.
		1325
989	=back	1326	=back
990		1327
991	=head2 SUPPORT FUNCTIONS	1328	=head2 SUPPORT FUNCTIONS
992		1329
993	=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION	1330	=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION
…		…
995	=over 4	1332	=over 4
996		1333
997	=item $fileno = IO::AIO::poll_fileno	1334	=item $fileno = IO::AIO::poll_fileno
998		1335
999	Return the I<request result pipe file descriptor>. This filehandle must be	1336	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	1337	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	1338	select and so on, see below or the SYNOPSIS). If the pipe becomes readable
1002	to call C<poll_cb> to check the results.	1339	you have to call C<poll_cb> to check the results.
1003		1340
1004	See C<poll_cb> for an example.	1341	See C<poll_cb> for an example.
1005		1342
1006	=item IO::AIO::poll_cb	1343	=item IO::AIO::poll_cb
1007		1344
1008	Process some outstanding events on the result pipe. You have to call this	1345	Process some outstanding events on the result pipe. You have to call this
1009	regularly. Returns the number of events processed. Returns immediately	1346	regularly. Returns C<0> if all events could be processed, or C<-1> if it
		1347	returned earlier for whatever reason. Returns immediately when no events
1010	when no events are outstanding. The amount of events processed depends on	1348	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>.	1349	C<IO::AIO::max_poll_req> and C<IO::AIO::max_poll_time>.
1012		1350
1013	If not all requests were processed for whatever reason, the filehandle	1351	If not all requests were processed for whatever reason, the filehandle
1014	will still be ready when C<poll_cb> returns.	1352	will still be ready when C<poll_cb> returns, so normally you don't have to
		1353	do anything special to have it called later.
1015		1354
1016	Example: Install an Event watcher that automatically calls	1355	Example: Install an Event watcher that automatically calls
1017	IO::AIO::poll_cb with high priority:	1356	IO::AIO::poll_cb with high priority (more examples can be found in the
		1357	SYNOPSIS section, at the top of this document):
1018		1358
1019	Event->io (fd => IO::AIO::poll_fileno,	1359	Event->io (fd => IO::AIO::poll_fileno,
1020	poll => 'r', async => 1,	1360	poll => 'r', async => 1,
1021	cb => \&IO::AIO::poll_cb);	1361	cb => \&IO::AIO::poll_cb);
		1362
		1363	=item IO::AIO::poll_wait
		1364
		1365	If there are any outstanding requests and none of them in the result
		1366	phase, wait till the result filehandle becomes ready for reading (simply
		1367	does a C<select> on the filehandle. This is useful if you want to
		1368	synchronously wait for some requests to finish).
		1369
		1370	See C<nreqs> for an example.
		1371
		1372	=item IO::AIO::poll
		1373
		1374	Waits until some requests have been handled.
		1375
		1376	Returns the number of requests processed, but is otherwise strictly
		1377	equivalent to:
		1378
		1379	IO::AIO::poll_wait, IO::AIO::poll_cb
		1380
		1381	=item IO::AIO::flush
		1382
		1383	Wait till all outstanding AIO requests have been handled.
		1384
		1385	Strictly equivalent to:
		1386
		1387	IO::AIO::poll_wait, IO::AIO::poll_cb
		1388	while IO::AIO::nreqs;
1022		1389
1023	=item IO::AIO::max_poll_reqs $nreqs	1390	=item IO::AIO::max_poll_reqs $nreqs
1024		1391
1025	=item IO::AIO::max_poll_time $seconds	1392	=item IO::AIO::max_poll_time $seconds
1026		1393
…		…
1051	# use a low priority so other tasks have priority	1418	# use a low priority so other tasks have priority
1052	Event->io (fd => IO::AIO::poll_fileno,	1419	Event->io (fd => IO::AIO::poll_fileno,
1053	poll => 'r', nice => 1,	1420	poll => 'r', nice => 1,
1054	cb => &IO::AIO::poll_cb);	1421	cb => &IO::AIO::poll_cb);
1055		1422
1056	=item IO::AIO::poll_wait	1423	=back
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		1424
1083	=head3 CONTROLLING THE NUMBER OF THREADS	1425	=head3 CONTROLLING THE NUMBER OF THREADS
		1426
		1427	=over
1084		1428
1085	=item IO::AIO::min_parallel $nthreads	1429	=item IO::AIO::min_parallel $nthreads
1086		1430
1087	Set the minimum number of AIO threads to C<$nthreads>. The current	1431	Set the minimum number of AIO threads to C<$nthreads>. The current
1088	default is C<8>, which means eight asynchronous operations can execute	1432	default is C<8>, which means eight asynchronous operations can execute
…		…
1129		1473
1130	The default is probably ok in most situations, especially if thread	1474	The default is probably ok in most situations, especially if thread
1131	creation is fast. If thread creation is very slow on your system you might	1475	creation is fast. If thread creation is very slow on your system you might
1132	want to use larger values.	1476	want to use larger values.
1133		1477
1134	=item $oldmaxreqs = IO::AIO::max_outstanding $maxreqs	1478	=item IO::AIO::max_outstanding $maxreqs
1135		1479
1136	This is a very bad function to use in interactive programs because it	1480	This is a very bad function to use in interactive programs because it
1137	blocks, and a bad way to reduce concurrency because it is inexact: Better	1481	blocks, and a bad way to reduce concurrency because it is inexact: Better
1138	use an C<aio_group> together with a feed callback.	1482	use an C<aio_group> together with a feed callback.
1139		1483
1140	Sets the maximum number of outstanding requests to C<$nreqs>. If you	1484	Sets the maximum number of outstanding requests to C<$nreqs>. If you
1141	to queue up more than this number of requests, the next call to the	1485	do queue up more than this number of requests, the next call to the
1142	C<poll_cb> (and C<poll_some> and other functions calling C<poll_cb>)	1486	C<poll_cb> (and C<poll_some> and other functions calling C<poll_cb>)
1143	function will block until the limit is no longer exceeded.	1487	function will block until the limit is no longer exceeded.
1144		1488
1145	The default value is very large, so there is no practical limit on the	1489	The default value is very large, so there is no practical limit on the
1146	number of outstanding requests.	1490	number of outstanding requests.
1147		1491
1148	You can still queue as many requests as you want. Therefore,	1492	You can still queue as many requests as you want. Therefore,
1149	C<max_oustsanding> is mainly useful in simple scripts (with low values) or	1493	C<max_outstanding> is mainly useful in simple scripts (with low values) or
1150	as a stop gap to shield against fatal memory overflow (with large values).	1494	as a stop gap to shield against fatal memory overflow (with large values).
1151		1495
		1496	=back
		1497
1152	=head3 STATISTICAL INFORMATION	1498	=head3 STATISTICAL INFORMATION
		1499
		1500	=over
1153		1501
1154	=item IO::AIO::nreqs	1502	=item IO::AIO::nreqs
1155		1503
1156	Returns the number of requests currently in the ready, execute or pending	1504	Returns the number of requests currently in the ready, execute or pending
1157	states (i.e. for which their callback has not been invoked yet).	1505	states (i.e. for which their callback has not been invoked yet).
…		…
1171	Returns the number of requests currently in the pending state (executed,	1519	Returns the number of requests currently in the pending state (executed,
1172	but not yet processed by poll_cb).	1520	but not yet processed by poll_cb).
1173		1521
1174	=back	1522	=back
1175		1523
		1524	=head3 MISCELLANEOUS FUNCTIONS
		1525
		1526	IO::AIO implements some functions that might be useful, but are not
		1527	asynchronous.
		1528
		1529	=over 4
		1530
		1531	=item IO::AIO::sendfile $ofh, $ifh, $offset, $count
		1532
		1533	Calls the C<eio_sendfile_sync> function, which is like C<aio_sendfile>,
		1534	but is blocking (this makes most sense if you know the input data is
		1535	likely cached already and the output filehandle is set to non-blocking
		1536	operations).
		1537
		1538	Returns the number of bytes copied, or C<-1> on error.
		1539
		1540	=item IO::AIO::fadvise $fh, $offset, $len, $advice
		1541
		1542	Simply calls the C<posix_fadvise> function (see it's
		1543	manpage for details). The following advice constants are
		1544	avaiable: C<IO::AIO::FADV_NORMAL>, C<IO::AIO::FADV_SEQUENTIAL>,
		1545	C<IO::AIO::FADV_RANDOM>, C<IO::AIO::FADV_NOREUSE>,
		1546	C<IO::AIO::FADV_WILLNEED>, C<IO::AIO::FADV_DONTNEED>.
		1547
		1548	On systems that do not implement C<posix_fadvise>, this function returns
		1549	ENOSYS, otherwise the return value of C<posix_fadvise>.
		1550
		1551	=item IO::AIO::mmap $scalar, $length, $prot, $flags, $fh[, $offset]
		1552
		1553	Memory-maps a file (or anonymous memory range) and attaches it to the
		1554	given C<$scalar>, which will act like a string scalar.
		1555
		1556	The only operations allowed on the scalar are C<substr>/C<vec> that don't
		1557	change the string length, and most read-only operations such as copying it
		1558	or searching it with regexes and so on.
		1559
		1560	Anything else is unsafe and will, at best, result in memory leaks.
		1561
		1562	The memory map associated with the C<$scalar> is automatically removed
		1563	when the C<$scalar> is destroyed, or when the C<IO::AIO::mmap> or
		1564	C<IO::AIO::munmap> functions are called.
		1565
		1566	This calls the C<mmap>(2) function internally. See your system's manual
		1567	page for details on the C<$length>, C<$prot> and C<$flags> parameters.
		1568
		1569	The C<$length> must be larger than zero and smaller than the actual
		1570	filesize.
		1571
		1572	C<$prot> is a combination of C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_EXEC>,
		1573	C<IO::AIO::PROT_READ> and/or C<IO::AIO::PROT_WRITE>,
		1574
		1575	C<$flags> can be a combination of C<IO::AIO::MAP_SHARED> or
		1576	C<IO::AIO::MAP_PRIVATE>, or a number of system-specific flags (when
		1577	not available, the are defined as 0): C<IO::AIO::MAP_ANONYMOUS>
		1578	(which is set to C<MAP_ANON> if your system only provides this
		1579	constant), C<IO::AIO::MAP_HUGETLB>, C<IO::AIO::MAP_LOCKED>,
		1580	C<IO::AIO::MAP_NORESERVE>, C<IO::AIO::MAP_POPULATE> or
		1581	C<IO::AIO::MAP_NONBLOCK>
		1582
		1583	If C<$fh> is C<undef>, then a file descriptor of C<-1> is passed.
		1584
		1585	C<$offset> is the offset from the start of the file - it generally must be
		1586	a multiple of C<IO::AIO::PAGESIZE> and defaults to C<0>.
		1587
		1588	Example:
		1589
		1590	use Digest::MD5;
		1591	use IO::AIO;
		1592
		1593	open my $fh, "<verybigfile"
		1594	or die "$!";
		1595
		1596	IO::AIO::mmap my $data, -s $fh, IO::AIO::PROT_READ, IO::AIO::MAP_SHARED, $fh
		1597	or die "verybigfile: $!";
		1598
		1599	my $fast_md5 = md5 $data;
		1600
		1601	=item IO::AIO::munmap $scalar
		1602
		1603	Removes a previous mmap and undefines the C<$scalar>.
		1604
		1605	=item IO::AIO::mlockall $flags
		1606
		1607	Calls the C<mlockall> function with the given C<$flags> (a combination of
		1608	C<IO::AIO::MCL_CURRENT> and C<IO::AIO::MCL__FUTURE>).
		1609
		1610	On systems that do not implement C<mlockall>, this function returns
		1611	ENOSYS, otherwise the return value of C<mlockall>.
		1612
		1613	=item IO::AIO::munlockall
		1614
		1615	Calls the C<munlockall> function.
		1616
		1617	On systems that do not implement C<munlockall>, this function returns
		1618	ENOSYS, otherwise the return value of C<munlockall>.
		1619
		1620	=back
		1621
1176	=cut	1622	=cut
1177		1623
1178	# support function to convert a fd into a perl filehandle
1179	sub _fd2fh {
1180	return undef if $_[0] < 0;
1181
1182	# try to generate nice filehandles
1183	my $sym = "IO::AIO::fd#$_[0]";
1184	local *$sym;
1185
1186	open *$sym, "+<&=$_[0]" # usually works under any unix
1187	or open *$sym, "<&=$_[0]" # cygwin needs this
1188	or open *$sym, ">&=$_[0]" # or this
1189	or return undef;
1190
1191	*$sym
1192	}
1193
1194	min_parallel 8;	1624	min_parallel 8;
1195		1625
1196	END { flush }	1626	END { flush }
1197		1627
1198	1;	1628	1;
		1629
		1630	=head1 EVENT LOOP INTEGRATION
		1631
		1632	It is recommended to use L<AnyEvent::AIO> to integrate IO::AIO
		1633	automatically into many event loops:
		1634
		1635	# AnyEvent integration (EV, Event, Glib, Tk, POE, urxvt, pureperl...)
		1636	use AnyEvent::AIO;
		1637
		1638	You can also integrate IO::AIO manually into many event loops, here are
		1639	some examples of how to do this:
		1640
		1641	# EV integration
		1642	my $aio_w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb;
		1643
		1644	# Event integration
		1645	Event->io (fd => IO::AIO::poll_fileno,
		1646	poll => 'r',
		1647	cb => \&IO::AIO::poll_cb);
		1648
		1649	# Glib/Gtk2 integration
		1650	add_watch Glib::IO IO::AIO::poll_fileno,
		1651	in => sub { IO::AIO::poll_cb; 1 };
		1652
		1653	# Tk integration
		1654	Tk::Event::IO->fileevent (IO::AIO::poll_fileno, "",
		1655	readable => \&IO::AIO::poll_cb);
		1656
		1657	# Danga::Socket integration
		1658	Danga::Socket->AddOtherFds (IO::AIO::poll_fileno =>
		1659	\&IO::AIO::poll_cb);
1199		1660
1200	=head2 FORK BEHAVIOUR	1661	=head2 FORK BEHAVIOUR
1201		1662
1202	This module should do "the right thing" when the process using it forks:	1663	This module should do "the right thing" when the process using it forks:
1203		1664
…		…
1221	bytes of memory. In addition, stat requests need a stat buffer (possibly	1682	bytes of memory. In addition, stat requests need a stat buffer (possibly
1222	a few hundred bytes), readdir requires a result buffer and so on. Perl	1683	a few hundred bytes), readdir requires a result buffer and so on. Perl
1223	scalars and other data passed into aio requests will also be locked and	1684	scalars and other data passed into aio requests will also be locked and
1224	will consume memory till the request has entered the done state.	1685	will consume memory till the request has entered the done state.
1225		1686
1226	This is now awfully much, so queuing lots of requests is not usually a	1687	This is not awfully much, so queuing lots of requests is not usually a
1227	problem.	1688	problem.
1228		1689
1229	Per-thread usage:	1690	Per-thread usage:
1230		1691
1231	In the execution phase, some aio requests require more memory for	1692	In the execution phase, some aio requests require more memory for
…		…
1236		1697
1237	Known bugs will be fixed in the next release.	1698	Known bugs will be fixed in the next release.
1238		1699
1239	=head1 SEE ALSO	1700	=head1 SEE ALSO
1240		1701
1241	L<Coro::AIO>.	1702	L<AnyEvent::AIO> for easy integration into event loops, L<Coro::AIO> for a
		1703	more natural syntax.
1242		1704
1243	=head1 AUTHOR	1705	=head1 AUTHOR
1244		1706
1245	Marc Lehmann <schmorp@schmorp.de>	1707	Marc Lehmann <schmorp@schmorp.de>
1246	http://home.schmorp.de/	1708	http://home.schmorp.de/

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