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Revision 1.105 by root, Sun Mar 25 00:20:27 2007 UTC vs.
Revision 1.184 by root, Mon Nov 1 22:03:43 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 = '3.7';
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
…		…
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
350	This call tries to make use of a native C<sendfile> syscall to provide	433	This call tries to make use of a native C<sendfile> syscall to provide
351	zero-copy operation. For this to work, C<$out_fh> should refer to a	434	zero-copy operation. For this to work, C<$out_fh> should refer to a
352	socket, and C<$in_fh> should refer to mmap'able file.	435	socket, and C<$in_fh> should refer to an mmap'able file.
353		436
354	If the native sendfile call fails or is not implemented, it will be	437	If a native sendfile cannot be found or it fails with C<ENOSYS>,
		438	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	439	it will be emulated, so you can call C<aio_sendfile> on any type of
356	regardless of the limitations of the operating system.	440	filehandle regardless of the limitations of the operating system.
357		441
358	Please note, however, that C<aio_sendfile> can read more bytes from	442	Please note, however, that C<aio_sendfile> can read more bytes from
359	C<$in_fh> than are written, and there is no way to find out how many	443	C<$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	444	bytes have been read from C<aio_sendfile> alone, as C<aio_sendfile> only
361	provides the number of bytes written to C<$out_fh>. Only if the result	445	provides the number of bytes written to C<$out_fh>. Only if the result
362	value equals C<$length> one can assume that C<$length> bytes have been	446	value equals C<$length> one can assume that C<$length> bytes have been
363	read.	447	read.
		448
364		449
365	=item aio_readahead $fh,$offset,$length, $callback->($retval)	450	=item aio_readahead $fh,$offset,$length, $callback->($retval)
366		451
367	C<aio_readahead> populates the page cache with data from a file so that	452	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<$offset>	453	subsequent reads from that file will not block on disk I/O. The C<$offset>
…		…
374	file. The current file offset of the file is left unchanged.	459	file. The current file offset of the file is left unchanged.
375		460
376	If that syscall doesn't exist (likely if your OS isn't Linux) it will be	461	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.	462	emulated by simply reading the data, which would have a similar effect.
378		463
		464
379	=item aio_stat $fh_or_path, $callback->($status)	465	=item aio_stat $fh_or_path, $callback->($status)
380		466
381	=item aio_lstat $fh, $callback->($status)	467	=item aio_lstat $fh, $callback->($status)
382		468
383	Works like perl's C<stat> or C<lstat> in void context. The callback will	469	Works like perl's C<stat> or C<lstat> in void context. The callback will
…		…
396	aio_stat "/etc/passwd", sub {	482	aio_stat "/etc/passwd", sub {
397	$_[0] and die "stat failed: $!";	483	$_[0] and die "stat failed: $!";
398	print "size is ", -s _, "\n";	484	print "size is ", -s _, "\n";
399	};	485	};
400		486
		487
		488	=item aio_statvfs $fh_or_path, $callback->($statvfs)
		489
		490	Works like the POSIX C<statvfs> or C<fstatvfs> syscalls, depending on
		491	whether a file handle or path was passed.
		492
		493	On success, the callback is passed a hash reference with the following
		494	members: C<bsize>, C<frsize>, C<blocks>, C<bfree>, C<bavail>, C<files>,
		495	C<ffree>, C<favail>, C<fsid>, C<flag> and C<namemax>. On failure, C<undef>
		496	is passed.
		497
		498	The following POSIX IO::AIO::ST_* constants are defined: C<ST_RDONLY> and
		499	C<ST_NOSUID>.
		500
		501	The following non-POSIX IO::AIO::ST_* flag masks are defined to
		502	their correct value when available, or to C<0> on systems that do
		503	not support them: C<ST_NODEV>, C<ST_NOEXEC>, C<ST_SYNCHRONOUS>,
		504	C<ST_MANDLOCK>, C<ST_WRITE>, C<ST_APPEND>, C<ST_IMMUTABLE>, C<ST_NOATIME>,
		505	C<ST_NODIRATIME> and C<ST_RELATIME>.
		506
		507	Example: stat C</wd> and dump out the data if successful.
		508
		509	aio_statvfs "/wd", sub {
		510	my $f = $_[0]
		511	or die "statvfs: $!";
		512
		513	use Data::Dumper;
		514	say Dumper $f;
		515	};
		516
		517	# result:
		518	{
		519	bsize => 1024,
		520	bfree => 4333064312,
		521	blocks => 10253828096,
		522	files => 2050765568,
		523	flag => 4096,
		524	favail => 2042092649,
		525	bavail => 4333064312,
		526	ffree => 2042092649,
		527	namemax => 255,
		528	frsize => 1024,
		529	fsid => 1810
		530	}
		531
		532
		533	=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
		534
		535	Works like perl's C<utime> function (including the special case of $atime
		536	and $mtime being undef). Fractional times are supported if the underlying
		537	syscalls support them.
		538
		539	When called with a pathname, uses utimes(2) if available, otherwise
		540	utime(2). If called on a file descriptor, uses futimes(2) if available,
		541	otherwise returns ENOSYS, so this is not portable.
		542
		543	Examples:
		544
		545	# set atime and mtime to current time (basically touch(1)):
		546	aio_utime "path", undef, undef;
		547	# set atime to current time and mtime to beginning of the epoch:
		548	aio_utime "path", time, undef; # undef==0
		549
		550
		551	=item aio_chown $fh_or_path, $uid, $gid, $callback->($status)
		552
		553	Works like perl's C<chown> function, except that C<undef> for either $uid
		554	or $gid is being interpreted as "do not change" (but -1 can also be used).
		555
		556	Examples:
		557
		558	# same as "chown root path" in the shell:
		559	aio_chown "path", 0, -1;
		560	# same as above:
		561	aio_chown "path", 0, undef;
		562
		563
		564	=item aio_truncate $fh_or_path, $offset, $callback->($status)
		565
		566	Works like truncate(2) or ftruncate(2).
		567
		568
		569	=item aio_chmod $fh_or_path, $mode, $callback->($status)
		570
		571	Works like perl's C<chmod> function.
		572
		573
401	=item aio_unlink $pathname, $callback->($status)	574	=item aio_unlink $pathname, $callback->($status)
402		575
403	Asynchronously unlink (delete) a file and call the callback with the	576	Asynchronously unlink (delete) a file and call the callback with the
404	result code.	577	result code.
405		578
		579
406	=item aio_mknod $path, $mode, $dev, $callback->($status)	580	=item aio_mknod $path, $mode, $dev, $callback->($status)
407		581
408	[EXPERIMENTAL]	582	[EXPERIMENTAL]
409		583
410	Asynchronously create a device node (or fifo). See mknod(2).	584	Asynchronously create a device node (or fifo). See mknod(2).
411		585
412	The only (POSIX-) portable way of calling this function is:	586	The only (POSIX-) portable way of calling this function is:
413		587
414	aio_mknod $path, IO::AIO::S_IFIFO | $mode, 0, sub { ...	588	aio_mknod $path, IO::AIO::S_IFIFO | $mode, 0, sub { ...
		589
415		590
416	=item aio_link $srcpath, $dstpath, $callback->($status)	591	=item aio_link $srcpath, $dstpath, $callback->($status)
417		592
418	Asynchronously create a new link to the existing object at C<$srcpath> at	593	Asynchronously create a new link to the existing object at C<$srcpath> at
419	the path C<$dstpath> and call the callback with the result code.	594	the path C<$dstpath> and call the callback with the result code.
420		595
		596
421	=item aio_symlink $srcpath, $dstpath, $callback->($status)	597	=item aio_symlink $srcpath, $dstpath, $callback->($status)
422		598
423	Asynchronously create a new symbolic link to the existing object at C<$srcpath> at	599	Asynchronously create a new symbolic link to the existing object at C<$srcpath> at
424	the path C<$dstpath> and call the callback with the result code.	600	the path C<$dstpath> and call the callback with the result code.
		601
425		602
426	=item aio_readlink $path, $callback->($link)	603	=item aio_readlink $path, $callback->($link)
427		604
428	Asynchronously read the symlink specified by C<$path> and pass it to	605	Asynchronously read the symlink specified by C<$path> and pass it to
429	the callback. If an error occurs, nothing or undef gets passed to the	606	the callback. If an error occurs, nothing or undef gets passed to the
430	callback.	607	callback.
431		608
		609
432	=item aio_rename $srcpath, $dstpath, $callback->($status)	610	=item aio_rename $srcpath, $dstpath, $callback->($status)
433		611
434	Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as	612	Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as
435	rename(2) and call the callback with the result code.	613	rename(2) and call the callback with the result code.
		614
436		615
437	=item aio_mkdir $pathname, $mode, $callback->($status)	616	=item aio_mkdir $pathname, $mode, $callback->($status)
438		617
439	Asynchronously mkdir (create) a directory and call the callback with	618	Asynchronously mkdir (create) a directory and call the callback with
440	the result code. C<$mode> will be modified by the umask at the time the	619	the result code. C<$mode> will be modified by the umask at the time the
441	request is executed, so do not change your umask.	620	request is executed, so do not change your umask.
442		621
		622
443	=item aio_rmdir $pathname, $callback->($status)	623	=item aio_rmdir $pathname, $callback->($status)
444		624
445	Asynchronously rmdir (delete) a directory and call the callback with the	625	Asynchronously rmdir (delete) a directory and call the callback with the
446	result code.	626	result code.
		627
447		628
448	=item aio_readdir $pathname, $callback->($entries)	629	=item aio_readdir $pathname, $callback->($entries)
449		630
450	Unlike the POSIX call of the same name, C<aio_readdir> reads an entire	631	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	632	directory (i.e. opendir + readdir + closedir). The entries will not be
452	sorted, and will B<NOT> include the C<.> and C<..> entries.	633	sorted, and will B<NOT> include the C<.> and C<..> entries.
453		634
454	The callback a single argument which is either C<undef> or an array-ref	635	The callback is passed a single argument which is either C<undef> or an
455	with the filenames.	636	array-ref with the filenames.
		637
		638
		639	=item aio_readdirx $pathname, $flags, $callback->($entries, $flags)
		640
		641	Quite similar to C<aio_readdir>, but the C<$flags> argument allows to tune
		642	behaviour and output format. In case of an error, C<$entries> will be
		643	C<undef>.
		644
		645	The flags are a combination of the following constants, ORed together (the
		646	flags will also be passed to the callback, possibly modified):
		647
		648	=over 4
		649
		650	=item IO::AIO::READDIR_DENTS
		651
		652	When this flag is off, then the callback gets an arrayref with of names
		653	only (as with C<aio_readdir>), otherwise it gets an arrayref with
		654	C<[$name, $type, $inode]> arrayrefs, each describing a single directory
		655	entry in more detail.
		656
		657	C<$name> is the name of the entry.
		658
		659	C<$type> is one of the C<IO::AIO::DT_xxx> constants:
		660
		661	C<IO::AIO::DT_UNKNOWN>, C<IO::AIO::DT_FIFO>, C<IO::AIO::DT_CHR>, C<IO::AIO::DT_DIR>,
		662	C<IO::AIO::DT_BLK>, C<IO::AIO::DT_REG>, C<IO::AIO::DT_LNK>, C<IO::AIO::DT_SOCK>,
		663	C<IO::AIO::DT_WHT>.
		664
		665	C<IO::AIO::DT_UNKNOWN> means just that: readdir does not know. If you need to
		666	know, you have to run stat yourself. Also, for speed reasons, the C<$type>
		667	scalars are read-only: you can not modify them.
		668
		669	C<$inode> is the inode number (which might not be exact on systems with 64
		670	bit inode numbers and 32 bit perls). This field has unspecified content on
		671	systems that do not deliver the inode information.
		672
		673	=item IO::AIO::READDIR_DIRS_FIRST
		674
		675	When this flag is set, then the names will be returned in an order where
		676	likely directories come first. This is useful when you need to quickly
		677	find directories, or you want to find all directories while avoiding to
		678	stat() each entry.
		679
		680	If the system returns type information in readdir, then this is used
		681	to find directories directly. Otherwise, likely directories are files
		682	beginning with ".", or otherwise files with no dots, of which files with
		683	short names are tried first.
		684
		685	=item IO::AIO::READDIR_STAT_ORDER
		686
		687	When this flag is set, then the names will be returned in an order
		688	suitable for stat()'ing each one. That is, when you plan to stat()
		689	all files in the given directory, then the returned order will likely
		690	be fastest.
		691
		692	If both this flag and C<IO::AIO::READDIR_DIRS_FIRST> are specified, then
		693	the likely dirs come first, resulting in a less optimal stat order.
		694
		695	=item IO::AIO::READDIR_FOUND_UNKNOWN
		696
		697	This flag should not be set when calling C<aio_readdirx>. Instead, it
		698	is being set by C<aio_readdirx>, when any of the C<$type>'s found were
		699	C<IO::AIO::DT_UNKNOWN>. The absense of this flag therefore indicates that all
		700	C<$type>'s are known, which can be used to speed up some algorithms.
		701
		702	=back
		703
456		704
457	=item aio_load $path, $data, $callback->($status)	705	=item aio_load $path, $data, $callback->($status)
458		706
459	This is a composite request that tries to fully load the given file into	707	This is a composite request that tries to fully load the given file into
460	memory. Status is the same as with aio_read.	708	memory. Status is the same as with aio_read.
461		709
462	=cut	710	=cut
463		711
464	sub aio_load($$;$) {	712	sub aio_load($$;$) {
465	aio_block {
466	my ($path, undef, $cb) = @_;	713	my ($path, undef, $cb) = @_;
467	my $data = \$_[1];	714	my $data = \$_[1];
468		715
469	my $pri = aioreq_pri;	716	my $pri = aioreq_pri;
470	my $grp = aio_group $cb;	717	my $grp = aio_group $cb;
		718
		719	aioreq_pri $pri;
		720	add $grp aio_open $path, O_RDONLY, 0, sub {
		721	my $fh = shift
		722	or return $grp->result (-1);
471		723
472	aioreq_pri $pri;	724	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), $$data, 0, sub {	725	add $grp aio_read $fh, 0, (-s $fh), $$data, 0, sub {
479	$grp->result ($_[0]);	726	$grp->result ($_[0]);
480	};
481	};	727	};
482
483	$grp
484	}	728	};
		729
		730	$grp
485	}	731	}
486		732
487	=item aio_copy $srcpath, $dstpath, $callback->($status)	733	=item aio_copy $srcpath, $dstpath, $callback->($status)
488		734
489	Try to copy the I<file> (directories not supported as either source or	735	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	736	destination) from C<$srcpath> to C<$dstpath> and call the callback with
491	the C<0> (error) or C<-1> ok.	737	a status of C<0> (ok) or C<-1> (error, see C<$!>).
492		738
493	This is a composite request that it creates the destination file with	739	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	740	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	741	C<aio_sendfile>, followed by restoring atime, mtime, access mode and
496	uid/gid, in that order.	742	uid/gid, in that order.
497		743
498	If an error occurs, the partial destination file will be unlinked, if	744	If an error occurs, the partial destination file will be unlinked, if
…		…
500	errors are being ignored.	746	errors are being ignored.
501		747
502	=cut	748	=cut
503		749
504	sub aio_copy($$;$) {	750	sub aio_copy($$;$) {
505	aio_block {
506	my ($src, $dst, $cb) = @_;	751	my ($src, $dst, $cb) = @_;
507		752
508	my $pri = aioreq_pri;	753	my $pri = aioreq_pri;
509	my $grp = aio_group $cb;	754	my $grp = aio_group $cb;
510		755
511	aioreq_pri $pri;	756	aioreq_pri $pri;
512	add $grp aio_open $src, O_RDONLY, 0, sub {	757	add $grp aio_open $src, O_RDONLY, 0, sub {
513	if (my $src_fh = $_[0]) {	758	if (my $src_fh = $_[0]) {
514	my @stat = stat $src_fh;	759	my @stat = stat $src_fh; # hmm, might block over nfs?
515		760
516	aioreq_pri $pri;	761	aioreq_pri $pri;
517	add $grp aio_open $dst, O_CREAT | O_WRONLY | O_TRUNC, 0200, sub {	762	add $grp aio_open $dst, O_CREAT | O_WRONLY | O_TRUNC, 0200, sub {
518	if (my $dst_fh = $_[0]) {	763	if (my $dst_fh = $_[0]) {
519	aioreq_pri $pri;	764	aioreq_pri $pri;
520	add $grp aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub {	765	add $grp aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub {
521	if ($_[0] == $stat[7]) {	766	if ($_[0] == $stat[7]) {
522	$grp->result (0);	767	$grp->result (0);
523	close $src_fh;	768	close $src_fh;
524		769
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 {	770	my $ch = sub {
531	$grp->result (-1);
532	close $src_fh;
533	close $dst_fh;
534
535	aioreq $pri;	771	aioreq_pri $pri;
		772	add $grp aio_chmod $dst_fh, $stat[2] & 07777, sub {
		773	aioreq_pri $pri;
		774	add $grp aio_chown $dst_fh, $stat[4], $stat[5], sub {
		775	aioreq_pri $pri;
536	add $grp aio_unlink $dst;	776	add $grp aio_close $dst_fh;
		777	}
		778	};
537	}	779	};
		780
		781	aioreq_pri $pri;
		782	add $grp aio_utime $dst_fh, $stat[8], $stat[9], sub {
		783	if ($_[0] < 0 && $! == ENOSYS) {
		784	aioreq_pri $pri;
		785	add $grp aio_utime $dst, $stat[8], $stat[9], $ch;
		786	} else {
		787	$ch->();
		788	}
		789	};
		790	} else {
		791	$grp->result (-1);
		792	close $src_fh;
		793	close $dst_fh;
		794
		795	aioreq $pri;
		796	add $grp aio_unlink $dst;
538	};	797	}
539	} else {
540	$grp->result (-1);
541	}	798	};
		799	} else {
		800	$grp->result (-1);
542	},	801	}
543
544	} else {
545	$grp->result (-1);
546	}	802	},
		803
		804	} else {
		805	$grp->result (-1);
547	};	806	}
548
549	$grp
550	}	807	};
		808
		809	$grp
551	}	810	}
552		811
553	=item aio_move $srcpath, $dstpath, $callback->($status)	812	=item aio_move $srcpath, $dstpath, $callback->($status)
554		813
555	Try to move the I<file> (directories not supported as either source or	814	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	815	destination) from C<$srcpath> to C<$dstpath> and call the callback with
557	the C<0> (error) or C<-1> ok.	816	a status of C<0> (ok) or C<-1> (error, see C<$!>).
558		817
559	This is a composite request that tries to rename(2) the file first. If	818	This is a composite request that tries to rename(2) the file first; if
560	rename files with C<EXDEV>, it copies the file with C<aio_copy> and, if	819	rename fails with C<EXDEV>, it copies the file with C<aio_copy> and, if
561	that is successful, unlinking the C<$srcpath>.	820	that is successful, unlinks the C<$srcpath>.
562		821
563	=cut	822	=cut
564		823
565	sub aio_move($$;$) {	824	sub aio_move($$;$) {
566	aio_block {
567	my ($src, $dst, $cb) = @_;	825	my ($src, $dst, $cb) = @_;
568		826
569	my $pri = aioreq_pri;	827	my $pri = aioreq_pri;
570	my $grp = aio_group $cb;	828	my $grp = aio_group $cb;
571		829
572	aioreq_pri $pri;	830	aioreq_pri $pri;
573	add $grp aio_rename $src, $dst, sub {	831	add $grp aio_rename $src, $dst, sub {
574	if ($_[0] && $! == EXDEV) {	832	if ($_[0] && $! == EXDEV) {
575	aioreq_pri $pri;	833	aioreq_pri $pri;
576	add $grp aio_copy $src, $dst, sub {	834	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]);	835	$grp->result ($_[0]);
		836
		837	if (!$_[0]) {
		838	aioreq_pri $pri;
		839	add $grp aio_unlink $src;
		840	}
586	}	841	};
		842	} else {
		843	$grp->result ($_[0]);
587	};	844	}
588
589	$grp
590	}	845	};
		846
		847	$grp
591	}	848	}
592		849
593	=item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs)	850	=item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs)
594		851
595	Scans a directory (similar to C<aio_readdir>) but additionally tries to	852	Scans a directory (similar to C<aio_readdir>) but additionally tries to
…		…
615		872
616	Implementation notes.	873	Implementation notes.
617		874
618	The C<aio_readdir> cannot be avoided, but C<stat()>'ing every entry can.	875	The C<aio_readdir> cannot be avoided, but C<stat()>'ing every entry can.
619		876
		877	If readdir returns file type information, then this is used directly to
		878	find directories.
		879
620	After reading the directory, the modification time, size etc. of the	880	Otherwise, after reading the directory, the modification time, size etc.
621	directory before and after the readdir is checked, and if they match (and	881	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	882	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	883	how many entries are directories (if >= 2). Otherwise, no knowledge of the
624	of subdirectories will be assumed.	884	number of subdirectories will be assumed.
625		885
626	Then entries will be sorted into likely directories (everything without	886	Then entries will be sorted into likely directories a non-initial dot
627	a non-initial dot currently) and likely non-directories (everything	887	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,	888	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	889	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	890	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	891	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	892	filesystems might detect the type of the entry without reading the inode
633	data (e.g. ext2fs filetype feature).	893	data (e.g. ext2fs filetype feature), even on systems that cannot return
		894	the filetype information on readdir.
634		895
635	If the known number of directories (link count - 2) has been reached, the	896	If the known number of directories (link count - 2) has been reached, the
636	rest of the entries is assumed to be non-directories.	897	rest of the entries is assumed to be non-directories.
637		898
638	This only works with certainty on POSIX (= UNIX) filesystems, which	899	This only works with certainty on POSIX (= UNIX) filesystems, which
…		…
643	directory counting heuristic.	904	directory counting heuristic.
644		905
645	=cut	906	=cut
646		907
647	sub aio_scandir($$;$) {	908	sub aio_scandir($$;$) {
648	aio_block {
649	my ($path, $maxreq, $cb) = @_;	909	my ($path, $maxreq, $cb) = @_;
650		910
651	my $pri = aioreq_pri;	911	my $pri = aioreq_pri;
652		912
653	my $grp = aio_group $cb;	913	my $grp = aio_group $cb;
654		914
655	$maxreq = 4 if $maxreq <= 0;	915	$maxreq = 4 if $maxreq <= 0;
656		916
657	# stat once	917	# stat once
		918	aioreq_pri $pri;
		919	add $grp aio_stat $path, sub {
		920	return $grp->result () if $_[0];
		921	my $now = time;
		922	my $hash1 = join ":", (stat _)[0,1,3,7,9];
		923
		924	# read the directory entries
658	aioreq_pri $pri;	925	aioreq_pri $pri;
659	add $grp aio_stat $path, sub {	926	add $grp aio_readdirx $path, READDIR_DIRS_FIRST, sub {
		927	my $entries = shift
660	return $grp->result () if $_[0];	928	or return $grp->result ();
661	my $now = time;
662	my $hash1 = join ":", (stat _)[0,1,3,7,9];
663		929
664	# read the directory entries	930	# stat the dir another time
665	aioreq_pri $pri;	931	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 {	932	add $grp aio_stat $path, sub {
673	my $hash2 = join ":", (stat _)[0,1,3,7,9];	933	my $hash2 = join ":", (stat _)[0,1,3,7,9];
674		934
675	my $ndirs;	935	my $ndirs;
676		936
677	# take the slow route if anything looks fishy	937	# take the slow route if anything looks fishy
678	if ($hash1 ne $hash2 or (stat _)[9] == $now) {	938	if ($hash1 ne $hash2 or (stat _)[9] == $now) {
679	$ndirs = -1;	939	$ndirs = -1;
680	} else {	940	} else {
681	# if nlink == 2, we are finished	941	# if nlink == 2, we are finished
682	# on non-posix-fs's, we rely on nlink < 2	942	# for non-posix-fs's, we rely on nlink < 2
683	$ndirs = (stat _)[3] - 2	943	$ndirs = (stat _)[3] - 2
684	or return $grp->result ([], $entries);	944	or return $grp->result ([], $entries);
685	}	945	}
686		946
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);	947	my (@dirs, @nondirs);
695		948
696	my $statgrp = add $grp aio_group sub {	949	my $statgrp = add $grp aio_group sub {
697	$grp->result (\@dirs, \@nondirs);	950	$grp->result (\@dirs, \@nondirs);
698	};	951	};
699		952
700	limit $statgrp $maxreq;	953	limit $statgrp $maxreq;
701	feed $statgrp sub {	954	feed $statgrp sub {
702	return unless @$entries;	955	return unless @$entries;
703	my $entry = pop @$entries;	956	my $entry = shift @$entries;
704		957
705	aioreq_pri $pri;	958	aioreq_pri $pri;
706	add $statgrp aio_stat "$path/$entry/.", sub {	959	add $statgrp aio_stat "$path/$entry/.", sub {
707	if ($_[0] < 0) {	960	if ($_[0] < 0) {
708	push @nondirs, $entry;	961	push @nondirs, $entry;
709	} else {	962	} else {
710	# need to check for real directory	963	# need to check for real directory
711	aioreq_pri $pri;	964	aioreq_pri $pri;
712	add $statgrp aio_lstat "$path/$entry", sub {	965	add $statgrp aio_lstat "$path/$entry", sub {
713	if (-d _) {	966	if (-d _) {
714	push @dirs, $entry;	967	push @dirs, $entry;
715		968
716	unless (--$ndirs) {	969	unless (--$ndirs) {
717	push @nondirs, @$entries;	970	push @nondirs, @$entries;
718	feed $statgrp;	971	feed $statgrp;
719	}
720	} else {
721	push @nondirs, $entry;
722	}	972	}
		973	} else {
		974	push @nondirs, $entry;
723	}	975	}
724	}	976	}
725	};	977	}
726	};	978	};
727	};	979	};
728	};	980	};
729	};	981	};
730
731	$grp
732	}	982	};
		983
		984	$grp
733	}	985	}
734		986
735	=item aio_rmtree $path, $callback->($status)	987	=item aio_rmtree $path, $callback->($status)
736		988
737	Delete a directory tree starting (and including) C<$path>, return the	989	Delete a directory tree starting (and including) C<$path>, return the
…		…
741		993
742	=cut	994	=cut
743		995
744	sub aio_rmtree;	996	sub aio_rmtree;
745	sub aio_rmtree($;$) {	997	sub aio_rmtree($;$) {
746	aio_block {
747	my ($path, $cb) = @_;	998	my ($path, $cb) = @_;
748		999
749	my $pri = aioreq_pri;	1000	my $pri = aioreq_pri;
750	my $grp = aio_group $cb;	1001	my $grp = aio_group $cb;
751		1002
752	aioreq_pri $pri;	1003	aioreq_pri $pri;
753	add $grp aio_scandir $path, 0, sub {	1004	add $grp aio_scandir $path, 0, sub {
754	my ($dirs, $nondirs) = @_;	1005	my ($dirs, $nondirs) = @_;
755		1006
756	my $dirgrp = aio_group sub {	1007	my $dirgrp = aio_group sub {
757	add $grp aio_rmdir $path, sub {	1008	add $grp aio_rmdir $path, sub {
758	$grp->result ($_[0]);	1009	$grp->result ($_[0]);
759	};
760	};	1010	};
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	};	1011	};
767		1012
768	$grp	1013	(aioreq_pri $pri), add $dirgrp aio_rmtree "$path/$_" for @$dirs;
		1014	(aioreq_pri $pri), add $dirgrp aio_unlink "$path/$_" for @$nondirs;
		1015
		1016	add $grp $dirgrp;
769	}	1017	};
		1018
		1019	$grp
770	}	1020	}
		1021
		1022	=item aio_sync $callback->($status)
		1023
		1024	Asynchronously call sync and call the callback when finished.
771		1025
772	=item aio_fsync $fh, $callback->($status)	1026	=item aio_fsync $fh, $callback->($status)
773		1027
774	Asynchronously call fsync on the given filehandle and call the callback	1028	Asynchronously call fsync on the given filehandle and call the callback
775	with the fsync result code.	1029	with the fsync result code.
…		…
779	Asynchronously call fdatasync on the given filehandle and call the	1033	Asynchronously call fdatasync on the given filehandle and call the
780	callback with the fdatasync result code.	1034	callback with the fdatasync result code.
781		1035
782	If this call isn't available because your OS lacks it or it couldn't be	1036	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.	1037	detected, it will be emulated by calling C<fsync> instead.
		1038
		1039	=item aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status)
		1040
		1041	Sync the data portion of the file specified by C<$offset> and C<$length>
		1042	to disk (but NOT the metadata), by calling the Linux-specific
		1043	sync_file_range call. If sync_file_range is not available or it returns
		1044	ENOSYS, then fdatasync or fsync is being substituted.
		1045
		1046	C<$flags> can be a combination of C<IO::AIO::SYNC_FILE_RANGE_WAIT_BEFORE>,
		1047	C<IO::AIO::SYNC_FILE_RANGE_WRITE> and
		1048	C<IO::AIO::SYNC_FILE_RANGE_WAIT_AFTER>: refer to the sync_file_range
		1049	manpage for details.
		1050
		1051	=item aio_pathsync $path, $callback->($status)
		1052
		1053	This request tries to open, fsync and close the given path. This is a
		1054	composite request intended to sync directories after directory operations
		1055	(E.g. rename). This might not work on all operating systems or have any
		1056	specific effect, but usually it makes sure that directory changes get
		1057	written to disc. It works for anything that can be opened for read-only,
		1058	not just directories.
		1059
		1060	Future versions of this function might fall back to other methods when
		1061	C<fsync> on the directory fails (such as calling C<sync>).
		1062
		1063	Passes C<0> when everything went ok, and C<-1> on error.
		1064
		1065	=cut
		1066
		1067	sub aio_pathsync($;$) {
		1068	my ($path, $cb) = @_;
		1069
		1070	my $pri = aioreq_pri;
		1071	my $grp = aio_group $cb;
		1072
		1073	aioreq_pri $pri;
		1074	add $grp aio_open $path, O_RDONLY, 0, sub {
		1075	my ($fh) = @_;
		1076	if ($fh) {
		1077	aioreq_pri $pri;
		1078	add $grp aio_fsync $fh, sub {
		1079	$grp->result ($_[0]);
		1080
		1081	aioreq_pri $pri;
		1082	add $grp aio_close $fh;
		1083	};
		1084	} else {
		1085	$grp->result (-1);
		1086	}
		1087	};
		1088
		1089	$grp
		1090	}
		1091
		1092	=item aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
		1093
		1094	This is a rather advanced IO::AIO call, which only works on mmap(2)ed
		1095	scalars (see the C<IO::AIO::mmap> function, although it also works on data
		1096	scalars managed by the L<Sys::Mmap> or L<Mmap> modules, note that the
		1097	scalar must only be modified in-place while an aio operation is pending on
		1098	it).
		1099
		1100	It calls the C<msync> function of your OS, if available, with the memory
		1101	area starting at C<$offset> in the string and ending C<$length> bytes
		1102	later. If C<$length> is negative, counts from the end, and if C<$length>
		1103	is C<undef>, then it goes till the end of the string. The flags can be
		1104	a combination of C<IO::AIO::MS_ASYNC>, C<IO::AIO::MS_INVALIDATE> and
		1105	C<IO::AIO::MS_SYNC>.
		1106
		1107	=item aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
		1108
		1109	This is a rather advanced IO::AIO call, which works best on mmap(2)ed
		1110	scalars.
		1111
		1112	It touches (reads or writes) all memory pages in the specified
		1113	range inside the scalar. All caveats and parameters are the same
		1114	as for C<aio_msync>, above, except for flags, which must be either
		1115	C<0> (which reads all pages and ensures they are instantiated) or
		1116	C<IO::AIO::MT_MODIFY>, which modifies the memory page s(by reading and
		1117	writing an octet from it, which dirties the page).
		1118
		1119	=item aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status)
		1120
		1121	This is a rather advanced IO::AIO call, which works best on mmap(2)ed
		1122	scalars.
		1123
		1124	It reads in all the pages of the underlying storage into memory (if any)
		1125	and locks them, so they are not getting swapped/paged out or removed.
		1126
		1127	If C<$length> is undefined, then the scalar will be locked till the end.
		1128
		1129	On systems that do not implement C<mlock>, this function returns C<-1>
		1130	and sets errno to C<ENOSYS>.
		1131
		1132	Note that the corresponding C<munlock> is synchronous and is
		1133	documented under L<MISCELLANEOUS FUNCTIONS>.
		1134
		1135	Example: open a file, mmap and mlock it - both will be undone when
		1136	C<$data> gets destroyed.
		1137
		1138	open my $fh, "<", $path or die "$path: $!";
		1139	my $data;
		1140	IO::AIO::mmap $data, -s $fh, IO::AIO::PROT_READ, IO::AIO::MAP_SHARED, $fh;
		1141	aio_mlock $data; # mlock in background
		1142
		1143	=item aio_mlockall $flags, $callback->($status)
		1144
		1145	Calls the C<mlockall> function with the given C<$flags> (a combination of
		1146	C<IO::AIO::MCL_CURRENT> and C<IO::AIO::MCL_FUTURE>).
		1147
		1148	On systems that do not implement C<mlockall>, this function returns C<-1>
		1149	and sets errno to C<ENOSYS>.
		1150
		1151	Note that the corresponding C<munlockall> is synchronous and is
		1152	documented under L<MISCELLANEOUS FUNCTIONS>.
		1153
		1154	Example: asynchronously lock all current and future pages into memory.
		1155
		1156	aio_mlockall IO::AIO::MCL_FUTURE;
784		1157
785	=item aio_group $callback->(...)	1158	=item aio_group $callback->(...)
786		1159
787	This is a very special aio request: Instead of doing something, it is a	1160	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	1161	container for other aio requests, which is useful if you want to bundle
…		…
838	=item cancel $req	1211	=item cancel $req
839		1212
840	Cancels the request, if possible. Has the effect of skipping execution	1213	Cancels the request, if possible. Has the effect of skipping execution
841	when entering the B<execute> state and skipping calling the callback when	1214	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	1215	entering the the B<result> state, but will leave the request otherwise
843	untouched. That means that requests that currently execute will not be	1216	untouched (with the exception of readdir). That means that requests that
844	stopped and resources held by the request will not be freed prematurely.	1217	currently execute will not be stopped and resources held by the request
		1218	will not be freed prematurely.
845		1219
846	=item cb $req $callback->(...)	1220	=item cb $req $callback->(...)
847		1221
848	Replace (or simply set) the callback registered to the request.	1222	Replace (or simply set) the callback registered to the request.
849		1223
…		…
900	Their lifetime, simplified, looks like this: when they are empty, they	1274	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	1275	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	1276	C<done> state, they will also finish. Otherwise they will continue to
903	exist.	1277	exist.
904		1278
905	That means after creating a group you have some time to add requests. And	1279	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	1280	(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	1281	the C<poll_cb>). And in the callbacks of those requests, you can add
908	itself finish.	1282	further requests to the group. And only when all those requests have
		1283	finished will the the group itself finish.
909		1284
910	=over 4	1285	=over 4
911		1286
912	=item add $grp ...	1287	=item add $grp ...
913		1288
…		…
922	=item $grp->cancel_subs	1297	=item $grp->cancel_subs
923		1298
924	Cancel all subrequests and clears any feeder, but not the group request	1299	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.	1300	itself. Useful when you queued a lot of events but got a result early.
926		1301
		1302	The group request will finish normally (you cannot add requests to the
		1303	group).
		1304
927	=item $grp->result (...)	1305	=item $grp->result (...)
928		1306
929	Set the result value(s) that will be passed to the group callback when all	1307	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	1308	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,	1309	of errno (just like calling C<errno> without an error number). By default,
932	no argument will be passed and errno is zero.	1310	no argument will be passed and errno is zero.
933		1311
934	=item $grp->errno ([$errno])	1312	=item $grp->errno ([$errno])
935		1313
…		…
946	=item feed $grp $callback->($grp)	1324	=item feed $grp $callback->($grp)
947		1325
948	Sets a feeder/generator on this group: every group can have an attached	1326	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,	1327	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,	1328	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	1329	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>	1330	C<aio_scandir> might generate hundreds of thousands C<aio_stat> requests,
953	requests, delaying any later requests for a long time.	1331	delaying any later requests for a long time.
954		1332
955	To avoid this, and allow incremental generation of requests, you can	1333	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	1334	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>,	1335	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	1336	below) requests active in the group itself and is expected to queue more
…		…
962	not impose any limits).	1340	not impose any limits).
963		1341
964	If the feed does not queue more requests when called, it will be	1342	If the feed does not queue more requests when called, it will be
965	automatically removed from the group.	1343	automatically removed from the group.
966		1344
967	If the feed limit is C<0>, it will be set to C<2> automatically.	1345	If the feed limit is C<0> when this method is called, it will be set to
		1346	C<2> automatically.
968		1347
969	Example:	1348	Example:
970		1349
971	# stat all files in @files, but only ever use four aio requests concurrently:	1350	# stat all files in @files, but only ever use four aio requests concurrently:
972		1351
…		…
984	Sets the feeder limit for the group: The feeder will be called whenever	1363	Sets the feeder limit for the group: The feeder will be called whenever
985	the group contains less than this many requests.	1364	the group contains less than this many requests.
986		1365
987	Setting the limit to C<0> will pause the feeding process.	1366	Setting the limit to C<0> will pause the feeding process.
988		1367
		1368	The default value for the limit is C<0>, but note that setting a feeder
		1369	automatically bumps it up to C<2>.
		1370
989	=back	1371	=back
990		1372
991	=head2 SUPPORT FUNCTIONS	1373	=head2 SUPPORT FUNCTIONS
992		1374
993	=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION	1375	=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION
…		…
995	=over 4	1377	=over 4
996		1378
997	=item $fileno = IO::AIO::poll_fileno	1379	=item $fileno = IO::AIO::poll_fileno
998		1380
999	Return the I<request result pipe file descriptor>. This filehandle must be	1381	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	1382	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	1383	select and so on, see below or the SYNOPSIS). If the pipe becomes readable
1002	to call C<poll_cb> to check the results.	1384	you have to call C<poll_cb> to check the results.
1003		1385
1004	See C<poll_cb> for an example.	1386	See C<poll_cb> for an example.
1005		1387
1006	=item IO::AIO::poll_cb	1388	=item IO::AIO::poll_cb
1007		1389
1008	Process some outstanding events on the result pipe. You have to call this	1390	Process some outstanding events on the result pipe. You have to call this
1009	regularly. Returns the number of events processed. Returns immediately	1391	regularly. Returns C<0> if all events could be processed, or C<-1> if it
		1392	returned earlier for whatever reason. Returns immediately when no events
1010	when no events are outstanding. The amount of events processed depends on	1393	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>.	1394	C<IO::AIO::max_poll_req> and C<IO::AIO::max_poll_time>.
1012		1395
1013	If not all requests were processed for whatever reason, the filehandle	1396	If not all requests were processed for whatever reason, the filehandle
1014	will still be ready when C<poll_cb> returns.	1397	will still be ready when C<poll_cb> returns, so normally you don't have to
		1398	do anything special to have it called later.
1015		1399
1016	Example: Install an Event watcher that automatically calls	1400	Example: Install an Event watcher that automatically calls
1017	IO::AIO::poll_cb with high priority:	1401	IO::AIO::poll_cb with high priority (more examples can be found in the
		1402	SYNOPSIS section, at the top of this document):
1018		1403
1019	Event->io (fd => IO::AIO::poll_fileno,	1404	Event->io (fd => IO::AIO::poll_fileno,
1020	poll => 'r', async => 1,	1405	poll => 'r', async => 1,
1021	cb => \&IO::AIO::poll_cb);	1406	cb => \&IO::AIO::poll_cb);
		1407
		1408	=item IO::AIO::poll_wait
		1409
		1410	If there are any outstanding requests and none of them in the result
		1411	phase, wait till the result filehandle becomes ready for reading (simply
		1412	does a C<select> on the filehandle. This is useful if you want to
		1413	synchronously wait for some requests to finish).
		1414
		1415	See C<nreqs> for an example.
		1416
		1417	=item IO::AIO::poll
		1418
		1419	Waits until some requests have been handled.
		1420
		1421	Returns the number of requests processed, but is otherwise strictly
		1422	equivalent to:
		1423
		1424	IO::AIO::poll_wait, IO::AIO::poll_cb
		1425
		1426	=item IO::AIO::flush
		1427
		1428	Wait till all outstanding AIO requests have been handled.
		1429
		1430	Strictly equivalent to:
		1431
		1432	IO::AIO::poll_wait, IO::AIO::poll_cb
		1433	while IO::AIO::nreqs;
1022		1434
1023	=item IO::AIO::max_poll_reqs $nreqs	1435	=item IO::AIO::max_poll_reqs $nreqs
1024		1436
1025	=item IO::AIO::max_poll_time $seconds	1437	=item IO::AIO::max_poll_time $seconds
1026		1438
…		…
1051	# use a low priority so other tasks have priority	1463	# use a low priority so other tasks have priority
1052	Event->io (fd => IO::AIO::poll_fileno,	1464	Event->io (fd => IO::AIO::poll_fileno,
1053	poll => 'r', nice => 1,	1465	poll => 'r', nice => 1,
1054	cb => &IO::AIO::poll_cb);	1466	cb => &IO::AIO::poll_cb);
1055		1467
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	1468	=back
1084		1469
1085	=head3 CONTROLLING THE NUMBER OF THREADS	1470	=head3 CONTROLLING THE NUMBER OF THREADS
1086		1471
1087	=over	1472	=over
…		…
1133		1518
1134	The default is probably ok in most situations, especially if thread	1519	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	1520	creation is fast. If thread creation is very slow on your system you might
1136	want to use larger values.	1521	want to use larger values.
1137		1522
1138	=item $oldmaxreqs = IO::AIO::max_outstanding $maxreqs	1523	=item IO::AIO::max_outstanding $maxreqs
1139		1524
1140	This is a very bad function to use in interactive programs because it	1525	This is a very bad function to use in interactive programs because it
1141	blocks, and a bad way to reduce concurrency because it is inexact: Better	1526	blocks, and a bad way to reduce concurrency because it is inexact: Better
1142	use an C<aio_group> together with a feed callback.	1527	use an C<aio_group> together with a feed callback.
1143		1528
1144	Sets the maximum number of outstanding requests to C<$nreqs>. If you	1529	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	1530	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>)	1531	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.	1532	function will block until the limit is no longer exceeded.
1148		1533
1149	The default value is very large, so there is no practical limit on the	1534	The default value is very large, so there is no practical limit on the
1150	number of outstanding requests.	1535	number of outstanding requests.
1151		1536
1152	You can still queue as many requests as you want. Therefore,	1537	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	1538	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).	1539	as a stop gap to shield against fatal memory overflow (with large values).
1155		1540
1156	=back	1541	=back
1157		1542
1158	=head3 STATISTICAL INFORMATION	1543	=head3 STATISTICAL INFORMATION
…		…
1179	Returns the number of requests currently in the pending state (executed,	1564	Returns the number of requests currently in the pending state (executed,
1180	but not yet processed by poll_cb).	1565	but not yet processed by poll_cb).
1181		1566
1182	=back	1567	=back
1183		1568
		1569	=head3 MISCELLANEOUS FUNCTIONS
		1570
		1571	IO::AIO implements some functions that might be useful, but are not
		1572	asynchronous.
		1573
		1574	=over 4
		1575
		1576	=item IO::AIO::sendfile $ofh, $ifh, $offset, $count
		1577
		1578	Calls the C<eio_sendfile_sync> function, which is like C<aio_sendfile>,
		1579	but is blocking (this makes most sense if you know the input data is
		1580	likely cached already and the output filehandle is set to non-blocking
		1581	operations).
		1582
		1583	Returns the number of bytes copied, or C<-1> on error.
		1584
		1585	=item IO::AIO::fadvise $fh, $offset, $len, $advice
		1586
		1587	Simply calls the C<posix_fadvise> function (see its
		1588	manpage for details). The following advice constants are
		1589	avaiable: C<IO::AIO::FADV_NORMAL>, C<IO::AIO::FADV_SEQUENTIAL>,
		1590	C<IO::AIO::FADV_RANDOM>, C<IO::AIO::FADV_NOREUSE>,
		1591	C<IO::AIO::FADV_WILLNEED>, C<IO::AIO::FADV_DONTNEED>.
		1592
		1593	On systems that do not implement C<posix_fadvise>, this function returns
		1594	ENOSYS, otherwise the return value of C<posix_fadvise>.
		1595
		1596	=item IO::AIO::madvise $scalar, $offset, $len, $advice
		1597
		1598	Simply calls the C<posix_madvise> function (see its
		1599	manpage for details). The following advice constants are
		1600	avaiable: C<IO::AIO::MADV_NORMAL>, C<IO::AIO::MADV_SEQUENTIAL>,
		1601	C<IO::AIO::MADV_RANDOM>, C<IO::AIO::MADV_WILLNEED>, C<IO::AIO::MADV_DONTNEED>.
		1602
		1603	On systems that do not implement C<posix_madvise>, this function returns
		1604	ENOSYS, otherwise the return value of C<posix_madvise>.
		1605
		1606	=item IO::AIO::mprotect $scalar, $offset, $len, $protect
		1607
		1608	Simply calls the C<mprotect> function on the preferably AIO::mmap'ed
		1609	$scalar (see its manpage for details). The following protect
		1610	constants are avaiable: C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_READ>,
		1611	C<IO::AIO::PROT_WRITE>, C<IO::AIO::PROT_EXEC>.
		1612
		1613	On systems that do not implement C<mprotect>, this function returns
		1614	ENOSYS, otherwise the return value of C<mprotect>.
		1615
		1616	=item IO::AIO::mmap $scalar, $length, $prot, $flags, $fh[, $offset]
		1617
		1618	Memory-maps a file (or anonymous memory range) and attaches it to the
		1619	given C<$scalar>, which will act like a string scalar.
		1620
		1621	The only operations allowed on the scalar are C<substr>/C<vec> that don't
		1622	change the string length, and most read-only operations such as copying it
		1623	or searching it with regexes and so on.
		1624
		1625	Anything else is unsafe and will, at best, result in memory leaks.
		1626
		1627	The memory map associated with the C<$scalar> is automatically removed
		1628	when the C<$scalar> is destroyed, or when the C<IO::AIO::mmap> or
		1629	C<IO::AIO::munmap> functions are called.
		1630
		1631	This calls the C<mmap>(2) function internally. See your system's manual
		1632	page for details on the C<$length>, C<$prot> and C<$flags> parameters.
		1633
		1634	The C<$length> must be larger than zero and smaller than the actual
		1635	filesize.
		1636
		1637	C<$prot> is a combination of C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_EXEC>,
		1638	C<IO::AIO::PROT_READ> and/or C<IO::AIO::PROT_WRITE>,
		1639
		1640	C<$flags> can be a combination of C<IO::AIO::MAP_SHARED> or
		1641	C<IO::AIO::MAP_PRIVATE>, or a number of system-specific flags (when
		1642	not available, the are defined as 0): C<IO::AIO::MAP_ANONYMOUS>
		1643	(which is set to C<MAP_ANON> if your system only provides this
		1644	constant), C<IO::AIO::MAP_HUGETLB>, C<IO::AIO::MAP_LOCKED>,
		1645	C<IO::AIO::MAP_NORESERVE>, C<IO::AIO::MAP_POPULATE> or
		1646	C<IO::AIO::MAP_NONBLOCK>
		1647
		1648	If C<$fh> is C<undef>, then a file descriptor of C<-1> is passed.
		1649
		1650	C<$offset> is the offset from the start of the file - it generally must be
		1651	a multiple of C<IO::AIO::PAGESIZE> and defaults to C<0>.
		1652
		1653	Example:
		1654
		1655	use Digest::MD5;
		1656	use IO::AIO;
		1657
		1658	open my $fh, "<verybigfile"
		1659	or die "$!";
		1660
		1661	IO::AIO::mmap my $data, -s $fh, IO::AIO::PROT_READ, IO::AIO::MAP_SHARED, $fh
		1662	or die "verybigfile: $!";
		1663
		1664	my $fast_md5 = md5 $data;
		1665
		1666	=item IO::AIO::munmap $scalar
		1667
		1668	Removes a previous mmap and undefines the C<$scalar>.
		1669
		1670	=item IO::AIO::munlock $scalar, $offset = 0, $length = undef
		1671
		1672	Calls the C<munlock> function, undoing the effects of a previous
		1673	C<aio_mlock> call (see its description for details).
		1674
		1675	=item IO::AIO::munlockall
		1676
		1677	Calls the C<munlockall> function.
		1678
		1679	On systems that do not implement C<munlockall>, this function returns
		1680	ENOSYS, otherwise the return value of C<munlockall>.
		1681
		1682	=back
		1683
1184	=cut	1684	=cut
1185		1685
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;	1686	min_parallel 8;
1203		1687
1204	END { flush }	1688	END { flush }
1205		1689
1206	1;	1690	1;
		1691
		1692	=head1 EVENT LOOP INTEGRATION
		1693
		1694	It is recommended to use L<AnyEvent::AIO> to integrate IO::AIO
		1695	automatically into many event loops:
		1696
		1697	# AnyEvent integration (EV, Event, Glib, Tk, POE, urxvt, pureperl...)
		1698	use AnyEvent::AIO;
		1699
		1700	You can also integrate IO::AIO manually into many event loops, here are
		1701	some examples of how to do this:
		1702
		1703	# EV integration
		1704	my $aio_w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb;
		1705
		1706	# Event integration
		1707	Event->io (fd => IO::AIO::poll_fileno,
		1708	poll => 'r',
		1709	cb => \&IO::AIO::poll_cb);
		1710
		1711	# Glib/Gtk2 integration
		1712	add_watch Glib::IO IO::AIO::poll_fileno,
		1713	in => sub { IO::AIO::poll_cb; 1 };
		1714
		1715	# Tk integration
		1716	Tk::Event::IO->fileevent (IO::AIO::poll_fileno, "",
		1717	readable => \&IO::AIO::poll_cb);
		1718
		1719	# Danga::Socket integration
		1720	Danga::Socket->AddOtherFds (IO::AIO::poll_fileno =>
		1721	\&IO::AIO::poll_cb);
1207		1722
1208	=head2 FORK BEHAVIOUR	1723	=head2 FORK BEHAVIOUR
1209		1724
1210	This module should do "the right thing" when the process using it forks:	1725	This module should do "the right thing" when the process using it forks:
1211		1726
…		…
1229	bytes of memory. In addition, stat requests need a stat buffer (possibly	1744	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	1745	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	1746	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.	1747	will consume memory till the request has entered the done state.
1233		1748
1234	This is now awfully much, so queuing lots of requests is not usually a	1749	This is not awfully much, so queuing lots of requests is not usually a
1235	problem.	1750	problem.
1236		1751
1237	Per-thread usage:	1752	Per-thread usage:
1238		1753
1239	In the execution phase, some aio requests require more memory for	1754	In the execution phase, some aio requests require more memory for
…		…
1244		1759
1245	Known bugs will be fixed in the next release.	1760	Known bugs will be fixed in the next release.
1246		1761
1247	=head1 SEE ALSO	1762	=head1 SEE ALSO
1248		1763
1249	L<Coro::AIO>.	1764	L<AnyEvent::AIO> for easy integration into event loops, L<Coro::AIO> for a
		1765	more natural syntax.
1250		1766
1251	=head1 AUTHOR	1767	=head1 AUTHOR
1252		1768
1253	Marc Lehmann <schmorp@schmorp.de>	1769	Marc Lehmann <schmorp@schmorp.de>
1254	http://home.schmorp.de/	1770	http://home.schmorp.de/

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