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Revision 1.96 by root, Fri Dec 22 04:05:50 2006 UTC vs.
Revision 1.183 by root, Sun Sep 12 03:40:05 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 = '2.21';	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
200	aio_move aio_copy aio_group aio_nop aio_mknod);	178	aio_fdatasync aio_sync_file_range aio_pathsync aio_readahead
		179	aio_rename aio_link aio_move aio_copy aio_group
		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::munlock $scalar, $offset = 0, $length = undef
		271	IO::AIO::munlockall
214		272
215	=head2 AIO REQUEST FUNCTIONS	273	=head2 AIO REQUEST FUNCTIONS
216		274
217	All the C<aio_*> calls are more or less thin wrappers around the syscall	275	All the C<aio_*> calls are more or less thin wrappers around the syscall
218	with the same name (sans C<aio_>). The arguments are similar or identical,	276	with the same name (sans C<aio_>). The arguments are similar or identical,
219	and they all accept an additional (and optional) C<$callback> argument	277	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	278	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	279	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	280	perl, which usually delivers "false") as its sole argument after the given
223	syscall has been executed asynchronously.	281	syscall has been executed asynchronously.
224		282
225	All functions expecting a filehandle keep a copy of the filehandle	283	All functions expecting a filehandle keep a copy of the filehandle
226	internally until the request has finished.	284	internally until the request has finished.
227		285
…		…
241	your pathnames to the locale (or other) encoding in effect in the user	299	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)	300	environment, d) use Glib::filename_from_unicode on unicode filenames or e)
243	use something else to ensure your scalar has the correct contents.	301	use something else to ensure your scalar has the correct contents.
244		302
245	This works, btw. independent of the internal UTF-8 bit, which IO::AIO	303	This works, btw. independent of the internal UTF-8 bit, which IO::AIO
246	handles correctly wether it is set or not.	304	handles correctly whether it is set or not.
247		305
248	=over 4	306	=over 4
249		307
250	=item $prev_pri = aioreq_pri [$pri]	308	=item $prev_pri = aioreq_pri [$pri]
251		309
…		…
271	aio_read $_[0], ..., sub {	329	aio_read $_[0], ..., sub {
272	...	330	...
273	};	331	};
274	};	332	};
275		333
		334
276	=item aioreq_nice $pri_adjust	335	=item aioreq_nice $pri_adjust
277		336
278	Similar to C<aioreq_pri>, but subtracts the given value from the current	337	Similar to C<aioreq_pri>, but subtracts the given value from the current
279	priority, so the effect is cumulative.	338	priority, so the effect is cumulative.
		339
280		340
281	=item aio_open $pathname, $flags, $mode, $callback->($fh)	341	=item aio_open $pathname, $flags, $mode, $callback->($fh)
282		342
283	Asynchronously open or create a file and call the callback with a newly	343	Asynchronously open or create a file and call the callback with a newly
284	created filehandle for the file.	344	created filehandle for the file.
…		…
290	list. They are the same as used by C<sysopen>.	350	list. They are the same as used by C<sysopen>.
291		351
292	Likewise, C<$mode> specifies the mode of the newly created file, if it	352	Likewise, C<$mode> specifies the mode of the newly created file, if it
293	didn't exist and C<O_CREAT> has been given, just like perl's C<sysopen>,	353	didn't exist and C<O_CREAT> has been given, just like perl's C<sysopen>,
294	except that it is mandatory (i.e. use C<0> if you don't create new files,	354	except that it is mandatory (i.e. use C<0> if you don't create new files,
295	and C<0666> or C<0777> if you do).	355	and C<0666> or C<0777> if you do). Note that the C<$mode> will be modified
		356	by the umask in effect then the request is being executed, so better never
		357	change the umask.
296		358
297	Example:	359	Example:
298		360
299	aio_open "/etc/passwd", O_RDONLY, 0, sub {	361	aio_open "/etc/passwd", IO::AIO::O_RDONLY, 0, sub {
300	if ($_[0]) {	362	if ($_[0]) {
301	print "open successful, fh is $_[0]\n";	363	print "open successful, fh is $_[0]\n";
302	...	364	...
303	} else {	365	} else {
304	die "open failed: $!\n";	366	die "open failed: $!\n";
305	}	367	}
306	};	368	};
307		369
		370
308	=item aio_close $fh, $callback->($status)	371	=item aio_close $fh, $callback->($status)
309		372
310	Asynchronously close a file and call the callback with the result	373	Asynchronously close a file and call the callback with the result
311	code. I<WARNING:> although accepted, you should not pass in a perl	374	code.
312	filehandle here, as perl will likely close the file descriptor another
313	time when the filehandle is destroyed. Normally, you can safely call perls
314	C<close> or just let filehandles go out of scope.
315		375
316	This is supposed to be a bug in the API, so that might change. It's	376	Unfortunately, you can't do this to perl. Perl I<insists> very strongly on
317	therefore best to avoid this function.	377	closing the file descriptor associated with the filehandle itself.
		378
		379	Therefore, C<aio_close> will not close the filehandle - instead it will
		380	use dup2 to overwrite the file descriptor with the write-end of a pipe
		381	(the pipe fd will be created on demand and will be cached).
		382
		383	Or in other words: the file descriptor will be closed, but it will not be
		384	free for reuse until the perl filehandle is closed.
		385
		386	=cut
318		387
319	=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)	388	=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
320		389
321	=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)	390	=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
322		391
323	Reads or writes C<length> bytes from the specified C<fh> and C<offset>	392	Reads or writes C<$length> bytes from or to the specified C<$fh> and
324	into the scalar given by C<data> and offset C<dataoffset> and calls the	393	C<$offset> into the scalar given by C<$data> and offset C<$dataoffset>
325	callback without the actual number of bytes read (or -1 on error, just	394	and calls the callback without the actual number of bytes read (or -1 on
326	like the syscall).	395	error, just like the syscall).
		396
		397	C<aio_read> will, like C<sysread>, shrink or grow the C<$data> scalar to
		398	offset plus the actual number of bytes read.
		399
		400	If C<$offset> is undefined, then the current file descriptor offset will
		401	be used (and updated), otherwise the file descriptor offset will not be
		402	changed by these calls.
		403
		404	If C<$length> is undefined in C<aio_write>, use the remaining length of
		405	C<$data>.
		406
		407	If C<$dataoffset> is less than zero, it will be counted from the end of
		408	C<$data>.
327		409
328	The C<$data> scalar I<MUST NOT> be modified in any way while the request	410	The C<$data> scalar I<MUST NOT> be modified in any way while the request
329	is outstanding. Modifying it can result in segfaults or WW3 (if the	411	is outstanding. Modifying it can result in segfaults or World War III (if
330	necessary/optional hardware is installed).	412	the necessary/optional hardware is installed).
331		413
332	Example: Read 15 bytes at offset 7 into scalar C<$buffer>, starting at	414	Example: Read 15 bytes at offset 7 into scalar C<$buffer>, starting at
333	offset C<0> within the scalar:	415	offset C<0> within the scalar:
334		416
335	aio_read $fh, 7, 15, $buffer, 0, sub {	417	aio_read $fh, 7, 15, $buffer, 0, sub {
336	$_[0] > 0 or die "read error: $!";	418	$_[0] > 0 or die "read error: $!";
337	print "read $_[0] bytes: <$buffer>\n";	419	print "read $_[0] bytes: <$buffer>\n";
338	};	420	};
		421
339		422
340	=item aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval)	423	=item aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval)
341		424
342	Tries to copy C<$length> bytes from C<$in_fh> to C<$out_fh>. It starts	425	Tries to copy C<$length> bytes from C<$in_fh> to C<$out_fh>. It starts
343	reading at byte offset C<$in_offset>, and starts writing at the current	426	reading at byte offset C<$in_offset>, and starts writing at the current
…		…
345	than one C<aio_sendfile> per C<$out_fh>, as they will interfere with each	428	than one C<aio_sendfile> per C<$out_fh>, as they will interfere with each
346	other.	429	other.
347		430
348	This call tries to make use of a native C<sendfile> syscall to provide	431	This call tries to make use of a native C<sendfile> syscall to provide
349	zero-copy operation. For this to work, C<$out_fh> should refer to a	432	zero-copy operation. For this to work, C<$out_fh> should refer to a
350	socket, and C<$in_fh> should refer to mmap'able file.	433	socket, and C<$in_fh> should refer to an mmap'able file.
351		434
352	If the native sendfile call fails or is not implemented, it will be	435	If a native sendfile cannot be found or it fails with C<ENOSYS>,
		436	C<ENOTSUP>, C<EOPNOTSUPP>, C<EAFNOSUPPORT>, C<EPROTOTYPE> or C<ENOTSOCK>,
353	emulated, so you can call C<aio_sendfile> on any type of filehandle	437	it will be emulated, so you can call C<aio_sendfile> on any type of
354	regardless of the limitations of the operating system.	438	filehandle regardless of the limitations of the operating system.
355		439
356	Please note, however, that C<aio_sendfile> can read more bytes from	440	Please note, however, that C<aio_sendfile> can read more bytes from
357	C<$in_fh> than are written, and there is no way to find out how many	441	C<$in_fh> than are written, and there is no way to find out how many
358	bytes have been read from C<aio_sendfile> alone, as C<aio_sendfile> only	442	bytes have been read from C<aio_sendfile> alone, as C<aio_sendfile> only
359	provides the number of bytes written to C<$out_fh>. Only if the result	443	provides the number of bytes written to C<$out_fh>. Only if the result
360	value equals C<$length> one can assume that C<$length> bytes have been	444	value equals C<$length> one can assume that C<$length> bytes have been
361	read.	445	read.
		446
362		447
363	=item aio_readahead $fh,$offset,$length, $callback->($retval)	448	=item aio_readahead $fh,$offset,$length, $callback->($retval)
364		449
365	C<aio_readahead> populates the page cache with data from a file so that	450	C<aio_readahead> populates the page cache with data from a file so that
366	subsequent reads from that file will not block on disk I/O. The C<$offset>	451	subsequent reads from that file will not block on disk I/O. The C<$offset>
…		…
372	file. The current file offset of the file is left unchanged.	457	file. The current file offset of the file is left unchanged.
373		458
374	If that syscall doesn't exist (likely if your OS isn't Linux) it will be	459	If that syscall doesn't exist (likely if your OS isn't Linux) it will be
375	emulated by simply reading the data, which would have a similar effect.	460	emulated by simply reading the data, which would have a similar effect.
376		461
		462
377	=item aio_stat $fh_or_path, $callback->($status)	463	=item aio_stat $fh_or_path, $callback->($status)
378		464
379	=item aio_lstat $fh, $callback->($status)	465	=item aio_lstat $fh, $callback->($status)
380		466
381	Works like perl's C<stat> or C<lstat> in void context. The callback will	467	Works like perl's C<stat> or C<lstat> in void context. The callback will
…		…
394	aio_stat "/etc/passwd", sub {	480	aio_stat "/etc/passwd", sub {
395	$_[0] and die "stat failed: $!";	481	$_[0] and die "stat failed: $!";
396	print "size is ", -s _, "\n";	482	print "size is ", -s _, "\n";
397	};	483	};
398		484
		485
		486	=item aio_statvfs $fh_or_path, $callback->($statvfs)
		487
		488	Works like the POSIX C<statvfs> or C<fstatvfs> syscalls, depending on
		489	whether a file handle or path was passed.
		490
		491	On success, the callback is passed a hash reference with the following
		492	members: C<bsize>, C<frsize>, C<blocks>, C<bfree>, C<bavail>, C<files>,
		493	C<ffree>, C<favail>, C<fsid>, C<flag> and C<namemax>. On failure, C<undef>
		494	is passed.
		495
		496	The following POSIX IO::AIO::ST_* constants are defined: C<ST_RDONLY> and
		497	C<ST_NOSUID>.
		498
		499	The following non-POSIX IO::AIO::ST_* flag masks are defined to
		500	their correct value when available, or to C<0> on systems that do
		501	not support them: C<ST_NODEV>, C<ST_NOEXEC>, C<ST_SYNCHRONOUS>,
		502	C<ST_MANDLOCK>, C<ST_WRITE>, C<ST_APPEND>, C<ST_IMMUTABLE>, C<ST_NOATIME>,
		503	C<ST_NODIRATIME> and C<ST_RELATIME>.
		504
		505	Example: stat C</wd> and dump out the data if successful.
		506
		507	aio_statvfs "/wd", sub {
		508	my $f = $_[0]
		509	or die "statvfs: $!";
		510
		511	use Data::Dumper;
		512	say Dumper $f;
		513	};
		514
		515	# result:
		516	{
		517	bsize => 1024,
		518	bfree => 4333064312,
		519	blocks => 10253828096,
		520	files => 2050765568,
		521	flag => 4096,
		522	favail => 2042092649,
		523	bavail => 4333064312,
		524	ffree => 2042092649,
		525	namemax => 255,
		526	frsize => 1024,
		527	fsid => 1810
		528	}
		529
		530
		531	=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
		532
		533	Works like perl's C<utime> function (including the special case of $atime
		534	and $mtime being undef). Fractional times are supported if the underlying
		535	syscalls support them.
		536
		537	When called with a pathname, uses utimes(2) if available, otherwise
		538	utime(2). If called on a file descriptor, uses futimes(2) if available,
		539	otherwise returns ENOSYS, so this is not portable.
		540
		541	Examples:
		542
		543	# set atime and mtime to current time (basically touch(1)):
		544	aio_utime "path", undef, undef;
		545	# set atime to current time and mtime to beginning of the epoch:
		546	aio_utime "path", time, undef; # undef==0
		547
		548
		549	=item aio_chown $fh_or_path, $uid, $gid, $callback->($status)
		550
		551	Works like perl's C<chown> function, except that C<undef> for either $uid
		552	or $gid is being interpreted as "do not change" (but -1 can also be used).
		553
		554	Examples:
		555
		556	# same as "chown root path" in the shell:
		557	aio_chown "path", 0, -1;
		558	# same as above:
		559	aio_chown "path", 0, undef;
		560
		561
		562	=item aio_truncate $fh_or_path, $offset, $callback->($status)
		563
		564	Works like truncate(2) or ftruncate(2).
		565
		566
		567	=item aio_chmod $fh_or_path, $mode, $callback->($status)
		568
		569	Works like perl's C<chmod> function.
		570
		571
399	=item aio_unlink $pathname, $callback->($status)	572	=item aio_unlink $pathname, $callback->($status)
400		573
401	Asynchronously unlink (delete) a file and call the callback with the	574	Asynchronously unlink (delete) a file and call the callback with the
402	result code.	575	result code.
403		576
		577
404	=item aio_mknod $path, $mode, $dev, $callback->($status)	578	=item aio_mknod $path, $mode, $dev, $callback->($status)
405		579
406	[EXPERIMENTAL]	580	[EXPERIMENTAL]
407		581
408	Asynchronously create a device node (or fifo). See mknod(2).	582	Asynchronously create a device node (or fifo). See mknod(2).
409		583
410	The only (POSIX-) portable way of calling this function is:	584	The only (POSIX-) portable way of calling this function is:
411		585
412	aio_mknod $path, IO::AIO::S_IFIFO | $mode, 0, sub { ...	586	aio_mknod $path, IO::AIO::S_IFIFO | $mode, 0, sub { ...
		587
413		588
414	=item aio_link $srcpath, $dstpath, $callback->($status)	589	=item aio_link $srcpath, $dstpath, $callback->($status)
415		590
416	Asynchronously create a new link to the existing object at C<$srcpath> at	591	Asynchronously create a new link to the existing object at C<$srcpath> at
417	the path C<$dstpath> and call the callback with the result code.	592	the path C<$dstpath> and call the callback with the result code.
418		593
		594
419	=item aio_symlink $srcpath, $dstpath, $callback->($status)	595	=item aio_symlink $srcpath, $dstpath, $callback->($status)
420		596
421	Asynchronously create a new symbolic link to the existing object at C<$srcpath> at	597	Asynchronously create a new symbolic link to the existing object at C<$srcpath> at
422	the path C<$dstpath> and call the callback with the result code.	598	the path C<$dstpath> and call the callback with the result code.
		599
423		600
424	=item aio_readlink $path, $callback->($link)	601	=item aio_readlink $path, $callback->($link)
425		602
426	Asynchronously read the symlink specified by C<$path> and pass it to	603	Asynchronously read the symlink specified by C<$path> and pass it to
427	the callback. If an error occurs, nothing or undef gets passed to the	604	the callback. If an error occurs, nothing or undef gets passed to the
428	callback.	605	callback.
429		606
		607
430	=item aio_rename $srcpath, $dstpath, $callback->($status)	608	=item aio_rename $srcpath, $dstpath, $callback->($status)
431		609
432	Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as	610	Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as
433	rename(2) and call the callback with the result code.	611	rename(2) and call the callback with the result code.
434		612
		613
		614	=item aio_mkdir $pathname, $mode, $callback->($status)
		615
		616	Asynchronously mkdir (create) a directory and call the callback with
		617	the result code. C<$mode> will be modified by the umask at the time the
		618	request is executed, so do not change your umask.
		619
		620
435	=item aio_rmdir $pathname, $callback->($status)	621	=item aio_rmdir $pathname, $callback->($status)
436		622
437	Asynchronously rmdir (delete) a directory and call the callback with the	623	Asynchronously rmdir (delete) a directory and call the callback with the
438	result code.	624	result code.
		625
439		626
440	=item aio_readdir $pathname, $callback->($entries)	627	=item aio_readdir $pathname, $callback->($entries)
441		628
442	Unlike the POSIX call of the same name, C<aio_readdir> reads an entire	629	Unlike the POSIX call of the same name, C<aio_readdir> reads an entire
443	directory (i.e. opendir + readdir + closedir). The entries will not be	630	directory (i.e. opendir + readdir + closedir). The entries will not be
444	sorted, and will B<NOT> include the C<.> and C<..> entries.	631	sorted, and will B<NOT> include the C<.> and C<..> entries.
445		632
446	The callback a single argument which is either C<undef> or an array-ref	633	The callback is passed a single argument which is either C<undef> or an
447	with the filenames.	634	array-ref with the filenames.
		635
		636
		637	=item aio_readdirx $pathname, $flags, $callback->($entries, $flags)
		638
		639	Quite similar to C<aio_readdir>, but the C<$flags> argument allows to tune
		640	behaviour and output format. In case of an error, C<$entries> will be
		641	C<undef>.
		642
		643	The flags are a combination of the following constants, ORed together (the
		644	flags will also be passed to the callback, possibly modified):
		645
		646	=over 4
		647
		648	=item IO::AIO::READDIR_DENTS
		649
		650	When this flag is off, then the callback gets an arrayref with of names
		651	only (as with C<aio_readdir>), otherwise it gets an arrayref with
		652	C<[$name, $type, $inode]> arrayrefs, each describing a single directory
		653	entry in more detail.
		654
		655	C<$name> is the name of the entry.
		656
		657	C<$type> is one of the C<IO::AIO::DT_xxx> constants:
		658
		659	C<IO::AIO::DT_UNKNOWN>, C<IO::AIO::DT_FIFO>, C<IO::AIO::DT_CHR>, C<IO::AIO::DT_DIR>,
		660	C<IO::AIO::DT_BLK>, C<IO::AIO::DT_REG>, C<IO::AIO::DT_LNK>, C<IO::AIO::DT_SOCK>,
		661	C<IO::AIO::DT_WHT>.
		662
		663	C<IO::AIO::DT_UNKNOWN> means just that: readdir does not know. If you need to
		664	know, you have to run stat yourself. Also, for speed reasons, the C<$type>
		665	scalars are read-only: you can not modify them.
		666
		667	C<$inode> is the inode number (which might not be exact on systems with 64
		668	bit inode numbers and 32 bit perls). This field has unspecified content on
		669	systems that do not deliver the inode information.
		670
		671	=item IO::AIO::READDIR_DIRS_FIRST
		672
		673	When this flag is set, then the names will be returned in an order where
		674	likely directories come first. This is useful when you need to quickly
		675	find directories, or you want to find all directories while avoiding to
		676	stat() each entry.
		677
		678	If the system returns type information in readdir, then this is used
		679	to find directories directly. Otherwise, likely directories are files
		680	beginning with ".", or otherwise files with no dots, of which files with
		681	short names are tried first.
		682
		683	=item IO::AIO::READDIR_STAT_ORDER
		684
		685	When this flag is set, then the names will be returned in an order
		686	suitable for stat()'ing each one. That is, when you plan to stat()
		687	all files in the given directory, then the returned order will likely
		688	be fastest.
		689
		690	If both this flag and C<IO::AIO::READDIR_DIRS_FIRST> are specified, then
		691	the likely dirs come first, resulting in a less optimal stat order.
		692
		693	=item IO::AIO::READDIR_FOUND_UNKNOWN
		694
		695	This flag should not be set when calling C<aio_readdirx>. Instead, it
		696	is being set by C<aio_readdirx>, when any of the C<$type>'s found were
		697	C<IO::AIO::DT_UNKNOWN>. The absense of this flag therefore indicates that all
		698	C<$type>'s are known, which can be used to speed up some algorithms.
		699
		700	=back
		701
		702
		703	=item aio_load $path, $data, $callback->($status)
		704
		705	This is a composite request that tries to fully load the given file into
		706	memory. Status is the same as with aio_read.
		707
		708	=cut
		709
		710	sub aio_load($$;$) {
		711	my ($path, undef, $cb) = @_;
		712	my $data = \$_[1];
		713
		714	my $pri = aioreq_pri;
		715	my $grp = aio_group $cb;
		716
		717	aioreq_pri $pri;
		718	add $grp aio_open $path, O_RDONLY, 0, sub {
		719	my $fh = shift
		720	or return $grp->result (-1);
		721
		722	aioreq_pri $pri;
		723	add $grp aio_read $fh, 0, (-s $fh), $$data, 0, sub {
		724	$grp->result ($_[0]);
		725	};
		726	};
		727
		728	$grp
		729	}
448		730
449	=item aio_copy $srcpath, $dstpath, $callback->($status)	731	=item aio_copy $srcpath, $dstpath, $callback->($status)
450		732
451	Try to copy the I<file> (directories not supported as either source or	733	Try to copy the I<file> (directories not supported as either source or
452	destination) from C<$srcpath> to C<$dstpath> and call the callback with	734	destination) from C<$srcpath> to C<$dstpath> and call the callback with
453	the C<0> (error) or C<-1> ok.	735	a status of C<0> (ok) or C<-1> (error, see C<$!>).
454		736
455	This is a composite request that it creates the destination file with	737	This is a composite request that creates the destination file with
456	mode 0200 and copies the contents of the source file into it using	738	mode 0200 and copies the contents of the source file into it using
457	C<aio_sendfile>, followed by restoring atime, mtime, access mode and	739	C<aio_sendfile>, followed by restoring atime, mtime, access mode and
458	uid/gid, in that order.	740	uid/gid, in that order.
459		741
460	If an error occurs, the partial destination file will be unlinked, if	742	If an error occurs, the partial destination file will be unlinked, if
…		…
462	errors are being ignored.	744	errors are being ignored.
463		745
464	=cut	746	=cut
465		747
466	sub aio_copy($$;$) {	748	sub aio_copy($$;$) {
467	aio_block {
468	my ($src, $dst, $cb) = @_;	749	my ($src, $dst, $cb) = @_;
469		750
470	my $pri = aioreq_pri;	751	my $pri = aioreq_pri;
471	my $grp = aio_group $cb;	752	my $grp = aio_group $cb;
472		753
473	aioreq_pri $pri;	754	aioreq_pri $pri;
474	add $grp aio_open $src, O_RDONLY, 0, sub {	755	add $grp aio_open $src, O_RDONLY, 0, sub {
475	if (my $src_fh = $_[0]) {	756	if (my $src_fh = $_[0]) {
476	my @stat = stat $src_fh;	757	my @stat = stat $src_fh; # hmm, might block over nfs?
477		758
478	aioreq_pri $pri;	759	aioreq_pri $pri;
479	add $grp aio_open $dst, O_CREAT | O_WRONLY | O_TRUNC, 0200, sub {	760	add $grp aio_open $dst, O_CREAT | O_WRONLY | O_TRUNC, 0200, sub {
480	if (my $dst_fh = $_[0]) {	761	if (my $dst_fh = $_[0]) {
481	aioreq_pri $pri;	762	aioreq_pri $pri;
482	add $grp aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub {	763	add $grp aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub {
483	if ($_[0] == $stat[7]) {	764	if ($_[0] == $stat[7]) {
484	$grp->result (0);	765	$grp->result (0);
485	close $src_fh;	766	close $src_fh;
486		767
487	# those should not normally block. should. should.
488	utime $stat[8], $stat[9], $dst;
489	chmod $stat[2] & 07777, $dst_fh;
490	chown $stat[4], $stat[5], $dst_fh;
491	close $dst_fh;
492	} else {	768	my $ch = sub {
493	$grp->result (-1);
494	close $src_fh;
495	close $dst_fh;
496
497	aioreq $pri;	769	aioreq_pri $pri;
		770	add $grp aio_chmod $dst_fh, $stat[2] & 07777, sub {
		771	aioreq_pri $pri;
		772	add $grp aio_chown $dst_fh, $stat[4], $stat[5], sub {
		773	aioreq_pri $pri;
498	add $grp aio_unlink $dst;	774	add $grp aio_close $dst_fh;
		775	}
		776	};
499	}	777	};
		778
		779	aioreq_pri $pri;
		780	add $grp aio_utime $dst_fh, $stat[8], $stat[9], sub {
		781	if ($_[0] < 0 && $! == ENOSYS) {
		782	aioreq_pri $pri;
		783	add $grp aio_utime $dst, $stat[8], $stat[9], $ch;
		784	} else {
		785	$ch->();
		786	}
		787	};
		788	} else {
		789	$grp->result (-1);
		790	close $src_fh;
		791	close $dst_fh;
		792
		793	aioreq $pri;
		794	add $grp aio_unlink $dst;
500	};	795	}
501	} else {
502	$grp->result (-1);
503	}	796	};
		797	} else {
		798	$grp->result (-1);
504	},	799	}
505
506	} else {
507	$grp->result (-1);
508	}	800	},
		801
		802	} else {
		803	$grp->result (-1);
509	};	804	}
510
511	$grp
512	}	805	};
		806
		807	$grp
513	}	808	}
514		809
515	=item aio_move $srcpath, $dstpath, $callback->($status)	810	=item aio_move $srcpath, $dstpath, $callback->($status)
516		811
517	Try to move the I<file> (directories not supported as either source or	812	Try to move the I<file> (directories not supported as either source or
518	destination) from C<$srcpath> to C<$dstpath> and call the callback with	813	destination) from C<$srcpath> to C<$dstpath> and call the callback with
519	the C<0> (error) or C<-1> ok.	814	a status of C<0> (ok) or C<-1> (error, see C<$!>).
520		815
521	This is a composite request that tries to rename(2) the file first. If	816	This is a composite request that tries to rename(2) the file first; if
522	rename files with C<EXDEV>, it copies the file with C<aio_copy> and, if	817	rename fails with C<EXDEV>, it copies the file with C<aio_copy> and, if
523	that is successful, unlinking the C<$srcpath>.	818	that is successful, unlinks the C<$srcpath>.
524		819
525	=cut	820	=cut
526		821
527	sub aio_move($$;$) {	822	sub aio_move($$;$) {
528	aio_block {
529	my ($src, $dst, $cb) = @_;	823	my ($src, $dst, $cb) = @_;
530		824
531	my $pri = aioreq_pri;	825	my $pri = aioreq_pri;
532	my $grp = aio_group $cb;	826	my $grp = aio_group $cb;
533		827
534	aioreq_pri $pri;	828	aioreq_pri $pri;
535	add $grp aio_rename $src, $dst, sub {	829	add $grp aio_rename $src, $dst, sub {
536	if ($_[0] && $! == EXDEV) {	830	if ($_[0] && $! == EXDEV) {
537	aioreq_pri $pri;	831	aioreq_pri $pri;
538	add $grp aio_copy $src, $dst, sub {	832	add $grp aio_copy $src, $dst, sub {
539	$grp->result ($_[0]);
540
541	if (!$_[0]) {
542	aioreq_pri $pri;
543	add $grp aio_unlink $src;
544	}
545	};
546	} else {
547	$grp->result ($_[0]);	833	$grp->result ($_[0]);
		834
		835	if (!$_[0]) {
		836	aioreq_pri $pri;
		837	add $grp aio_unlink $src;
		838	}
548	}	839	};
		840	} else {
		841	$grp->result ($_[0]);
549	};	842	}
550
551	$grp
552	}	843	};
		844
		845	$grp
553	}	846	}
554		847
555	=item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs)	848	=item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs)
556		849
557	Scans a directory (similar to C<aio_readdir>) but additionally tries to	850	Scans a directory (similar to C<aio_readdir>) but additionally tries to
…		…
577		870
578	Implementation notes.	871	Implementation notes.
579		872
580	The C<aio_readdir> cannot be avoided, but C<stat()>'ing every entry can.	873	The C<aio_readdir> cannot be avoided, but C<stat()>'ing every entry can.
581		874
		875	If readdir returns file type information, then this is used directly to
		876	find directories.
		877
582	After reading the directory, the modification time, size etc. of the	878	Otherwise, after reading the directory, the modification time, size etc.
583	directory before and after the readdir is checked, and if they match (and	879	of the directory before and after the readdir is checked, and if they
584	isn't the current time), the link count will be used to decide how many	880	match (and isn't the current time), the link count will be used to decide
585	entries are directories (if >= 2). Otherwise, no knowledge of the number	881	how many entries are directories (if >= 2). Otherwise, no knowledge of the
586	of subdirectories will be assumed.	882	number of subdirectories will be assumed.
587		883
588	Then entries will be sorted into likely directories (everything without	884	Then entries will be sorted into likely directories a non-initial dot
589	a non-initial dot currently) and likely non-directories (everything	885	currently) and likely non-directories (see C<aio_readdirx>). Then every
590	else). Then every entry plus an appended C</.> will be C<stat>'ed,	886	entry plus an appended C</.> will be C<stat>'ed, likely directories first,
591	likely directories first. If that succeeds, it assumes that the entry	887	in order of their inode numbers. If that succeeds, it assumes that the
592	is a directory or a symlink to directory (which will be checked	888	entry is a directory or a symlink to directory (which will be checked
593	seperately). This is often faster than stat'ing the entry itself because	889	seperately). This is often faster than stat'ing the entry itself because
594	filesystems might detect the type of the entry without reading the inode	890	filesystems might detect the type of the entry without reading the inode
595	data (e.g. ext2fs filetype feature).	891	data (e.g. ext2fs filetype feature), even on systems that cannot return
		892	the filetype information on readdir.
596		893
597	If the known number of directories (link count - 2) has been reached, the	894	If the known number of directories (link count - 2) has been reached, the
598	rest of the entries is assumed to be non-directories.	895	rest of the entries is assumed to be non-directories.
599		896
600	This only works with certainty on POSIX (= UNIX) filesystems, which	897	This only works with certainty on POSIX (= UNIX) filesystems, which
…		…
604	as those tend to return 0 or 1 as link counts, which disables the	901	as those tend to return 0 or 1 as link counts, which disables the
605	directory counting heuristic.	902	directory counting heuristic.
606		903
607	=cut	904	=cut
608		905
609	sub aio_scandir($$$) {	906	sub aio_scandir($$;$) {
610	aio_block {
611	my ($path, $maxreq, $cb) = @_;	907	my ($path, $maxreq, $cb) = @_;
612		908
613	my $pri = aioreq_pri;	909	my $pri = aioreq_pri;
614		910
615	my $grp = aio_group $cb;	911	my $grp = aio_group $cb;
616		912
617	$maxreq = 4 if $maxreq <= 0;	913	$maxreq = 4 if $maxreq <= 0;
618		914
619	# stat once	915	# stat once
		916	aioreq_pri $pri;
		917	add $grp aio_stat $path, sub {
		918	return $grp->result () if $_[0];
		919	my $now = time;
		920	my $hash1 = join ":", (stat _)[0,1,3,7,9];
		921
		922	# read the directory entries
620	aioreq_pri $pri;	923	aioreq_pri $pri;
621	add $grp aio_stat $path, sub {	924	add $grp aio_readdirx $path, READDIR_DIRS_FIRST, sub {
		925	my $entries = shift
622	return $grp->result () if $_[0];	926	or return $grp->result ();
623	my $now = time;
624	my $hash1 = join ":", (stat _)[0,1,3,7,9];
625		927
626	# read the directory entries	928	# stat the dir another time
627	aioreq_pri $pri;	929	aioreq_pri $pri;
628	add $grp aio_readdir $path, sub {
629	my $entries = shift
630	or return $grp->result ();
631
632	# stat the dir another time
633	aioreq_pri $pri;
634	add $grp aio_stat $path, sub {	930	add $grp aio_stat $path, sub {
635	my $hash2 = join ":", (stat _)[0,1,3,7,9];	931	my $hash2 = join ":", (stat _)[0,1,3,7,9];
636		932
637	my $ndirs;	933	my $ndirs;
638		934
639	# take the slow route if anything looks fishy	935	# take the slow route if anything looks fishy
640	if ($hash1 ne $hash2 or (stat _)[9] == $now) {	936	if ($hash1 ne $hash2 or (stat _)[9] == $now) {
641	$ndirs = -1;	937	$ndirs = -1;
642	} else {	938	} else {
643	# if nlink == 2, we are finished	939	# if nlink == 2, we are finished
644	# on non-posix-fs's, we rely on nlink < 2	940	# for non-posix-fs's, we rely on nlink < 2
645	$ndirs = (stat _)[3] - 2	941	$ndirs = (stat _)[3] - 2
646	or return $grp->result ([], $entries);	942	or return $grp->result ([], $entries);
647	}	943	}
648		944
649	# sort into likely dirs and likely nondirs
650	# dirs == files without ".", short entries first
651	$entries = [map $_->[0],
652	sort { $b->[1] cmp $a->[1] }
653	map [$_, sprintf "%s%04d", (/.\./ ? "1" : "0"), length],
654	@$entries];
655
656	my (@dirs, @nondirs);	945	my (@dirs, @nondirs);
657		946
658	my $statgrp = add $grp aio_group sub {	947	my $statgrp = add $grp aio_group sub {
659	$grp->result (\@dirs, \@nondirs);	948	$grp->result (\@dirs, \@nondirs);
660	};	949	};
661		950
662	limit $statgrp $maxreq;	951	limit $statgrp $maxreq;
663	feed $statgrp sub {	952	feed $statgrp sub {
664	return unless @$entries;	953	return unless @$entries;
665	my $entry = pop @$entries;	954	my $entry = shift @$entries;
666		955
667	aioreq_pri $pri;	956	aioreq_pri $pri;
668	add $statgrp aio_stat "$path/$entry/.", sub {	957	add $statgrp aio_stat "$path/$entry/.", sub {
669	if ($_[0] < 0) {	958	if ($_[0] < 0) {
670	push @nondirs, $entry;	959	push @nondirs, $entry;
671	} else {	960	} else {
672	# need to check for real directory	961	# need to check for real directory
673	aioreq_pri $pri;	962	aioreq_pri $pri;
674	add $statgrp aio_lstat "$path/$entry", sub {	963	add $statgrp aio_lstat "$path/$entry", sub {
675	if (-d _) {	964	if (-d _) {
676	push @dirs, $entry;	965	push @dirs, $entry;
677		966
678	unless (--$ndirs) {	967	unless (--$ndirs) {
679	push @nondirs, @$entries;	968	push @nondirs, @$entries;
680	feed $statgrp;	969	feed $statgrp;
681	}
682	} else {
683	push @nondirs, $entry;
684	}	970	}
		971	} else {
		972	push @nondirs, $entry;
685	}	973	}
686	}	974	}
687	};	975	}
688	};	976	};
689	};	977	};
690	};	978	};
691	};	979	};
692
693	$grp
694	}	980	};
		981
		982	$grp
695	}	983	}
		984
		985	=item aio_rmtree $path, $callback->($status)
		986
		987	Delete a directory tree starting (and including) C<$path>, return the
		988	status of the final C<rmdir> only. This is a composite request that
		989	uses C<aio_scandir> to recurse into and rmdir directories, and unlink
		990	everything else.
		991
		992	=cut
		993
		994	sub aio_rmtree;
		995	sub aio_rmtree($;$) {
		996	my ($path, $cb) = @_;
		997
		998	my $pri = aioreq_pri;
		999	my $grp = aio_group $cb;
		1000
		1001	aioreq_pri $pri;
		1002	add $grp aio_scandir $path, 0, sub {
		1003	my ($dirs, $nondirs) = @_;
		1004
		1005	my $dirgrp = aio_group sub {
		1006	add $grp aio_rmdir $path, sub {
		1007	$grp->result ($_[0]);
		1008	};
		1009	};
		1010
		1011	(aioreq_pri $pri), add $dirgrp aio_rmtree "$path/$_" for @$dirs;
		1012	(aioreq_pri $pri), add $dirgrp aio_unlink "$path/$_" for @$nondirs;
		1013
		1014	add $grp $dirgrp;
		1015	};
		1016
		1017	$grp
		1018	}
		1019
		1020	=item aio_sync $callback->($status)
		1021
		1022	Asynchronously call sync and call the callback when finished.
696		1023
697	=item aio_fsync $fh, $callback->($status)	1024	=item aio_fsync $fh, $callback->($status)
698		1025
699	Asynchronously call fsync on the given filehandle and call the callback	1026	Asynchronously call fsync on the given filehandle and call the callback
700	with the fsync result code.	1027	with the fsync result code.
…		…
704	Asynchronously call fdatasync on the given filehandle and call the	1031	Asynchronously call fdatasync on the given filehandle and call the
705	callback with the fdatasync result code.	1032	callback with the fdatasync result code.
706		1033
707	If this call isn't available because your OS lacks it or it couldn't be	1034	If this call isn't available because your OS lacks it or it couldn't be
708	detected, it will be emulated by calling C<fsync> instead.	1035	detected, it will be emulated by calling C<fsync> instead.
		1036
		1037	=item aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status)
		1038
		1039	Sync the data portion of the file specified by C<$offset> and C<$length>
		1040	to disk (but NOT the metadata), by calling the Linux-specific
		1041	sync_file_range call. If sync_file_range is not available or it returns
		1042	ENOSYS, then fdatasync or fsync is being substituted.
		1043
		1044	C<$flags> can be a combination of C<IO::AIO::SYNC_FILE_RANGE_WAIT_BEFORE>,
		1045	C<IO::AIO::SYNC_FILE_RANGE_WRITE> and
		1046	C<IO::AIO::SYNC_FILE_RANGE_WAIT_AFTER>: refer to the sync_file_range
		1047	manpage for details.
		1048
		1049	=item aio_pathsync $path, $callback->($status)
		1050
		1051	This request tries to open, fsync and close the given path. This is a
		1052	composite request intended to sync directories after directory operations
		1053	(E.g. rename). This might not work on all operating systems or have any
		1054	specific effect, but usually it makes sure that directory changes get
		1055	written to disc. It works for anything that can be opened for read-only,
		1056	not just directories.
		1057
		1058	Future versions of this function might fall back to other methods when
		1059	C<fsync> on the directory fails (such as calling C<sync>).
		1060
		1061	Passes C<0> when everything went ok, and C<-1> on error.
		1062
		1063	=cut
		1064
		1065	sub aio_pathsync($;$) {
		1066	my ($path, $cb) = @_;
		1067
		1068	my $pri = aioreq_pri;
		1069	my $grp = aio_group $cb;
		1070
		1071	aioreq_pri $pri;
		1072	add $grp aio_open $path, O_RDONLY, 0, sub {
		1073	my ($fh) = @_;
		1074	if ($fh) {
		1075	aioreq_pri $pri;
		1076	add $grp aio_fsync $fh, sub {
		1077	$grp->result ($_[0]);
		1078
		1079	aioreq_pri $pri;
		1080	add $grp aio_close $fh;
		1081	};
		1082	} else {
		1083	$grp->result (-1);
		1084	}
		1085	};
		1086
		1087	$grp
		1088	}
		1089
		1090	=item aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
		1091
		1092	This is a rather advanced IO::AIO call, which only works on mmap(2)ed
		1093	scalars (see the C<IO::AIO::mmap> function, although it also works on data
		1094	scalars managed by the L<Sys::Mmap> or L<Mmap> modules, note that the
		1095	scalar must only be modified in-place while an aio operation is pending on
		1096	it).
		1097
		1098	It calls the C<msync> function of your OS, if available, with the memory
		1099	area starting at C<$offset> in the string and ending C<$length> bytes
		1100	later. If C<$length> is negative, counts from the end, and if C<$length>
		1101	is C<undef>, then it goes till the end of the string. The flags can be
		1102	a combination of C<IO::AIO::MS_ASYNC>, C<IO::AIO::MS_INVALIDATE> and
		1103	C<IO::AIO::MS_SYNC>.
		1104
		1105	=item aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
		1106
		1107	This is a rather advanced IO::AIO call, which works best on mmap(2)ed
		1108	scalars.
		1109
		1110	It touches (reads or writes) all memory pages in the specified
		1111	range inside the scalar. All caveats and parameters are the same
		1112	as for C<aio_msync>, above, except for flags, which must be either
		1113	C<0> (which reads all pages and ensures they are instantiated) or
		1114	C<IO::AIO::MT_MODIFY>, which modifies the memory page s(by reading and
		1115	writing an octet from it, which dirties the page).
		1116
		1117	=item aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status)
		1118
		1119	This is a rather advanced IO::AIO call, which works best on mmap(2)ed
		1120	scalars.
		1121
		1122	It reads in all the pages of the underlying storage into memory (if any)
		1123	and locks them, so they are not getting swapped/paged out or removed.
		1124
		1125	If C<$length> is undefined, then the scalar will be locked till the end.
		1126
		1127	On systems that do not implement C<mlock>, this function returns C<-1>
		1128	and sets errno to C<ENOSYS>.
		1129
		1130	Note that the corresponding C<munlock> is synchronous and is
		1131	documented under L<MISCELLANEOUS FUNCTIONS>.
		1132
		1133	Example: open a file, mmap and mlock it - both will be undone when
		1134	C<$data> gets destroyed.
		1135
		1136	open my $fh, "<", $path or die "$path: $!";
		1137	my $data;
		1138	IO::AIO::mmap $data, -s $fh, IO::AIO::PROT_READ, IO::AIO::MAP_SHARED, $fh;
		1139	aio_mlock $data; # mlock in background
		1140
		1141	=item aio_mlockall $flags, $callback->($status)
		1142
		1143	Calls the C<mlockall> function with the given C<$flags> (a combination of
		1144	C<IO::AIO::MCL_CURRENT> and C<IO::AIO::MCL_FUTURE>).
		1145
		1146	On systems that do not implement C<mlockall>, this function returns C<-1>
		1147	and sets errno to C<ENOSYS>.
		1148
		1149	Note that the corresponding C<munlockall> is synchronous and is
		1150	documented under L<MISCELLANEOUS FUNCTIONS>.
		1151
		1152	Example: asynchronously lock all current and future pages into memory.
		1153
		1154	aio_mlockall IO::AIO::MCL_FUTURE;
709		1155
710	=item aio_group $callback->(...)	1156	=item aio_group $callback->(...)
711		1157
712	This is a very special aio request: Instead of doing something, it is a	1158	This is a very special aio request: Instead of doing something, it is a
713	container for other aio requests, which is useful if you want to bundle	1159	container for other aio requests, which is useful if you want to bundle
…		…
763	=item cancel $req	1209	=item cancel $req
764		1210
765	Cancels the request, if possible. Has the effect of skipping execution	1211	Cancels the request, if possible. Has the effect of skipping execution
766	when entering the B<execute> state and skipping calling the callback when	1212	when entering the B<execute> state and skipping calling the callback when
767	entering the the B<result> state, but will leave the request otherwise	1213	entering the the B<result> state, but will leave the request otherwise
768	untouched. That means that requests that currently execute will not be	1214	untouched (with the exception of readdir). That means that requests that
769	stopped and resources held by the request will not be freed prematurely.	1215	currently execute will not be stopped and resources held by the request
		1216	will not be freed prematurely.
770		1217
771	=item cb $req $callback->(...)	1218	=item cb $req $callback->(...)
772		1219
773	Replace (or simply set) the callback registered to the request.	1220	Replace (or simply set) the callback registered to the request.
774		1221
…		…
825	Their lifetime, simplified, looks like this: when they are empty, they	1272	Their lifetime, simplified, looks like this: when they are empty, they
826	will finish very quickly. If they contain only requests that are in the	1273	will finish very quickly. If they contain only requests that are in the
827	C<done> state, they will also finish. Otherwise they will continue to	1274	C<done> state, they will also finish. Otherwise they will continue to
828	exist.	1275	exist.
829		1276
830	That means after creating a group you have some time to add requests. And	1277	That means after creating a group you have some time to add requests
831	in the callbacks of those requests, you can add further requests to the	1278	(precisely before the callback has been invoked, which is only done within
832	group. And only when all those requests have finished will the the group	1279	the C<poll_cb>). And in the callbacks of those requests, you can add
833	itself finish.	1280	further requests to the group. And only when all those requests have
		1281	finished will the the group itself finish.
834		1282
835	=over 4	1283	=over 4
836		1284
837	=item add $grp ...	1285	=item add $grp ...
838		1286
…		…
847	=item $grp->cancel_subs	1295	=item $grp->cancel_subs
848		1296
849	Cancel all subrequests and clears any feeder, but not the group request	1297	Cancel all subrequests and clears any feeder, but not the group request
850	itself. Useful when you queued a lot of events but got a result early.	1298	itself. Useful when you queued a lot of events but got a result early.
851		1299
		1300	The group request will finish normally (you cannot add requests to the
		1301	group).
		1302
852	=item $grp->result (...)	1303	=item $grp->result (...)
853		1304
854	Set the result value(s) that will be passed to the group callback when all	1305	Set the result value(s) that will be passed to the group callback when all
855	subrequests have finished and set thre groups errno to the current value	1306	subrequests have finished and set the groups errno to the current value
856	of errno (just like calling C<errno> without an error number). By default,	1307	of errno (just like calling C<errno> without an error number). By default,
857	no argument will be passed and errno is zero.	1308	no argument will be passed and errno is zero.
858		1309
859	=item $grp->errno ([$errno])	1310	=item $grp->errno ([$errno])
860		1311
…		…
871	=item feed $grp $callback->($grp)	1322	=item feed $grp $callback->($grp)
872		1323
873	Sets a feeder/generator on this group: every group can have an attached	1324	Sets a feeder/generator on this group: every group can have an attached
874	generator that generates requests if idle. The idea behind this is that,	1325	generator that generates requests if idle. The idea behind this is that,
875	although you could just queue as many requests as you want in a group,	1326	although you could just queue as many requests as you want in a group,
876	this might starve other requests for a potentially long time. For	1327	this might starve other requests for a potentially long time. For example,
877	example, C<aio_scandir> might generate hundreds of thousands C<aio_stat>	1328	C<aio_scandir> might generate hundreds of thousands C<aio_stat> requests,
878	requests, delaying any later requests for a long time.	1329	delaying any later requests for a long time.
879		1330
880	To avoid this, and allow incremental generation of requests, you can	1331	To avoid this, and allow incremental generation of requests, you can
881	instead a group and set a feeder on it that generates those requests. The	1332	instead a group and set a feeder on it that generates those requests. The
882	feed callback will be called whenever there are few enough (see C<limit>,	1333	feed callback will be called whenever there are few enough (see C<limit>,
883	below) requests active in the group itself and is expected to queue more	1334	below) requests active in the group itself and is expected to queue more
…		…
887	not impose any limits).	1338	not impose any limits).
888		1339
889	If the feed does not queue more requests when called, it will be	1340	If the feed does not queue more requests when called, it will be
890	automatically removed from the group.	1341	automatically removed from the group.
891		1342
892	If the feed limit is C<0>, it will be set to C<2> automatically.	1343	If the feed limit is C<0> when this method is called, it will be set to
		1344	C<2> automatically.
893		1345
894	Example:	1346	Example:
895		1347
896	# stat all files in @files, but only ever use four aio requests concurrently:	1348	# stat all files in @files, but only ever use four aio requests concurrently:
897		1349
…		…
909	Sets the feeder limit for the group: The feeder will be called whenever	1361	Sets the feeder limit for the group: The feeder will be called whenever
910	the group contains less than this many requests.	1362	the group contains less than this many requests.
911		1363
912	Setting the limit to C<0> will pause the feeding process.	1364	Setting the limit to C<0> will pause the feeding process.
913		1365
		1366	The default value for the limit is C<0>, but note that setting a feeder
		1367	automatically bumps it up to C<2>.
		1368
914	=back	1369	=back
915		1370
916	=head2 SUPPORT FUNCTIONS	1371	=head2 SUPPORT FUNCTIONS
917		1372
918	=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION	1373	=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION
…		…
920	=over 4	1375	=over 4
921		1376
922	=item $fileno = IO::AIO::poll_fileno	1377	=item $fileno = IO::AIO::poll_fileno
923		1378
924	Return the I<request result pipe file descriptor>. This filehandle must be	1379	Return the I<request result pipe file descriptor>. This filehandle must be
925	polled for reading by some mechanism outside this module (e.g. Event or	1380	polled for reading by some mechanism outside this module (e.g. EV, Glib,
926	select, see below or the SYNOPSIS). If the pipe becomes readable you have	1381	select and so on, see below or the SYNOPSIS). If the pipe becomes readable
927	to call C<poll_cb> to check the results.	1382	you have to call C<poll_cb> to check the results.
928		1383
929	See C<poll_cb> for an example.	1384	See C<poll_cb> for an example.
930		1385
931	=item IO::AIO::poll_cb	1386	=item IO::AIO::poll_cb
932		1387
933	Process some outstanding events on the result pipe. You have to call this	1388	Process some outstanding events on the result pipe. You have to call this
934	regularly. Returns the number of events processed. Returns immediately	1389	regularly. Returns C<0> if all events could be processed, or C<-1> if it
		1390	returned earlier for whatever reason. Returns immediately when no events
935	when no events are outstanding. The amount of events processed depends on	1391	are outstanding. The amount of events processed depends on the settings of
936	the settings of C<IO::AIO::max_poll_req> and C<IO::AIO::max_poll_time>.	1392	C<IO::AIO::max_poll_req> and C<IO::AIO::max_poll_time>.
937		1393
938	If not all requests were processed for whatever reason, the filehandle	1394	If not all requests were processed for whatever reason, the filehandle
939	will still be ready when C<poll_cb> returns.	1395	will still be ready when C<poll_cb> returns, so normally you don't have to
		1396	do anything special to have it called later.
940		1397
941	Example: Install an Event watcher that automatically calls	1398	Example: Install an Event watcher that automatically calls
942	IO::AIO::poll_cb with high priority:	1399	IO::AIO::poll_cb with high priority (more examples can be found in the
		1400	SYNOPSIS section, at the top of this document):
943		1401
944	Event->io (fd => IO::AIO::poll_fileno,	1402	Event->io (fd => IO::AIO::poll_fileno,
945	poll => 'r', async => 1,	1403	poll => 'r', async => 1,
946	cb => \&IO::AIO::poll_cb);	1404	cb => \&IO::AIO::poll_cb);
		1405
		1406	=item IO::AIO::poll_wait
		1407
		1408	If there are any outstanding requests and none of them in the result
		1409	phase, wait till the result filehandle becomes ready for reading (simply
		1410	does a C<select> on the filehandle. This is useful if you want to
		1411	synchronously wait for some requests to finish).
		1412
		1413	See C<nreqs> for an example.
		1414
		1415	=item IO::AIO::poll
		1416
		1417	Waits until some requests have been handled.
		1418
		1419	Returns the number of requests processed, but is otherwise strictly
		1420	equivalent to:
		1421
		1422	IO::AIO::poll_wait, IO::AIO::poll_cb
		1423
		1424	=item IO::AIO::flush
		1425
		1426	Wait till all outstanding AIO requests have been handled.
		1427
		1428	Strictly equivalent to:
		1429
		1430	IO::AIO::poll_wait, IO::AIO::poll_cb
		1431	while IO::AIO::nreqs;
947		1432
948	=item IO::AIO::max_poll_reqs $nreqs	1433	=item IO::AIO::max_poll_reqs $nreqs
949		1434
950	=item IO::AIO::max_poll_time $seconds	1435	=item IO::AIO::max_poll_time $seconds
951		1436
…		…
976	# use a low priority so other tasks have priority	1461	# use a low priority so other tasks have priority
977	Event->io (fd => IO::AIO::poll_fileno,	1462	Event->io (fd => IO::AIO::poll_fileno,
978	poll => 'r', nice => 1,	1463	poll => 'r', nice => 1,
979	cb => &IO::AIO::poll_cb);	1464	cb => &IO::AIO::poll_cb);
980		1465
981	=item IO::AIO::poll_wait	1466	=back
982
983	If there are any outstanding requests and none of them in the result
984	phase, wait till the result filehandle becomes ready for reading (simply
985	does a C<select> on the filehandle. This is useful if you want to
986	synchronously wait for some requests to finish).
987
988	See C<nreqs> for an example.
989
990	=item IO::AIO::poll
991
992	Waits until some requests have been handled.
993
994	Returns the number of requests processed, but is otherwise strictly
995	equivalent to:
996
997	IO::AIO::poll_wait, IO::AIO::poll_cb
998
999	=item IO::AIO::flush
1000
1001	Wait till all outstanding AIO requests have been handled.
1002
1003	Strictly equivalent to:
1004
1005	IO::AIO::poll_wait, IO::AIO::poll_cb
1006	while IO::AIO::nreqs;
1007		1467
1008	=head3 CONTROLLING THE NUMBER OF THREADS	1468	=head3 CONTROLLING THE NUMBER OF THREADS
		1469
		1470	=over
1009		1471
1010	=item IO::AIO::min_parallel $nthreads	1472	=item IO::AIO::min_parallel $nthreads
1011		1473
1012	Set the minimum number of AIO threads to C<$nthreads>. The current	1474	Set the minimum number of AIO threads to C<$nthreads>. The current
1013	default is C<8>, which means eight asynchronous operations can execute	1475	default is C<8>, which means eight asynchronous operations can execute
…		…
1054		1516
1055	The default is probably ok in most situations, especially if thread	1517	The default is probably ok in most situations, especially if thread
1056	creation is fast. If thread creation is very slow on your system you might	1518	creation is fast. If thread creation is very slow on your system you might
1057	want to use larger values.	1519	want to use larger values.
1058		1520
1059	=item $oldmaxreqs = IO::AIO::max_outstanding $maxreqs	1521	=item IO::AIO::max_outstanding $maxreqs
1060		1522
1061	This is a very bad function to use in interactive programs because it	1523	This is a very bad function to use in interactive programs because it
1062	blocks, and a bad way to reduce concurrency because it is inexact: Better	1524	blocks, and a bad way to reduce concurrency because it is inexact: Better
1063	use an C<aio_group> together with a feed callback.	1525	use an C<aio_group> together with a feed callback.
1064		1526
1065	Sets the maximum number of outstanding requests to C<$nreqs>. If you	1527	Sets the maximum number of outstanding requests to C<$nreqs>. If you
1066	to queue up more than this number of requests, the next call to the	1528	do queue up more than this number of requests, the next call to the
1067	C<poll_cb> (and C<poll_some> and other functions calling C<poll_cb>)	1529	C<poll_cb> (and C<poll_some> and other functions calling C<poll_cb>)
1068	function will block until the limit is no longer exceeded.	1530	function will block until the limit is no longer exceeded.
1069		1531
1070	The default value is very large, so there is no practical limit on the	1532	The default value is very large, so there is no practical limit on the
1071	number of outstanding requests.	1533	number of outstanding requests.
1072		1534
1073	You can still queue as many requests as you want. Therefore,	1535	You can still queue as many requests as you want. Therefore,
1074	C<max_oustsanding> is mainly useful in simple scripts (with low values) or	1536	C<max_outstanding> is mainly useful in simple scripts (with low values) or
1075	as a stop gap to shield against fatal memory overflow (with large values).	1537	as a stop gap to shield against fatal memory overflow (with large values).
1076		1538
		1539	=back
		1540
1077	=head3 STATISTICAL INFORMATION	1541	=head3 STATISTICAL INFORMATION
		1542
		1543	=over
1078		1544
1079	=item IO::AIO::nreqs	1545	=item IO::AIO::nreqs
1080		1546
1081	Returns the number of requests currently in the ready, execute or pending	1547	Returns the number of requests currently in the ready, execute or pending
1082	states (i.e. for which their callback has not been invoked yet).	1548	states (i.e. for which their callback has not been invoked yet).
…		…
1096	Returns the number of requests currently in the pending state (executed,	1562	Returns the number of requests currently in the pending state (executed,
1097	but not yet processed by poll_cb).	1563	but not yet processed by poll_cb).
1098		1564
1099	=back	1565	=back
1100		1566
		1567	=head3 MISCELLANEOUS FUNCTIONS
		1568
		1569	IO::AIO implements some functions that might be useful, but are not
		1570	asynchronous.
		1571
		1572	=over 4
		1573
		1574	=item IO::AIO::sendfile $ofh, $ifh, $offset, $count
		1575
		1576	Calls the C<eio_sendfile_sync> function, which is like C<aio_sendfile>,
		1577	but is blocking (this makes most sense if you know the input data is
		1578	likely cached already and the output filehandle is set to non-blocking
		1579	operations).
		1580
		1581	Returns the number of bytes copied, or C<-1> on error.
		1582
		1583	=item IO::AIO::fadvise $fh, $offset, $len, $advice
		1584
		1585	Simply calls the C<posix_fadvise> function (see it's
		1586	manpage for details). The following advice constants are
		1587	avaiable: C<IO::AIO::FADV_NORMAL>, C<IO::AIO::FADV_SEQUENTIAL>,
		1588	C<IO::AIO::FADV_RANDOM>, C<IO::AIO::FADV_NOREUSE>,
		1589	C<IO::AIO::FADV_WILLNEED>, C<IO::AIO::FADV_DONTNEED>.
		1590
		1591	On systems that do not implement C<posix_fadvise>, this function returns
		1592	ENOSYS, otherwise the return value of C<posix_fadvise>.
		1593
		1594	=item IO::AIO::mmap $scalar, $length, $prot, $flags, $fh[, $offset]
		1595
		1596	Memory-maps a file (or anonymous memory range) and attaches it to the
		1597	given C<$scalar>, which will act like a string scalar.
		1598
		1599	The only operations allowed on the scalar are C<substr>/C<vec> that don't
		1600	change the string length, and most read-only operations such as copying it
		1601	or searching it with regexes and so on.
		1602
		1603	Anything else is unsafe and will, at best, result in memory leaks.
		1604
		1605	The memory map associated with the C<$scalar> is automatically removed
		1606	when the C<$scalar> is destroyed, or when the C<IO::AIO::mmap> or
		1607	C<IO::AIO::munmap> functions are called.
		1608
		1609	This calls the C<mmap>(2) function internally. See your system's manual
		1610	page for details on the C<$length>, C<$prot> and C<$flags> parameters.
		1611
		1612	The C<$length> must be larger than zero and smaller than the actual
		1613	filesize.
		1614
		1615	C<$prot> is a combination of C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_EXEC>,
		1616	C<IO::AIO::PROT_READ> and/or C<IO::AIO::PROT_WRITE>,
		1617
		1618	C<$flags> can be a combination of C<IO::AIO::MAP_SHARED> or
		1619	C<IO::AIO::MAP_PRIVATE>, or a number of system-specific flags (when
		1620	not available, the are defined as 0): C<IO::AIO::MAP_ANONYMOUS>
		1621	(which is set to C<MAP_ANON> if your system only provides this
		1622	constant), C<IO::AIO::MAP_HUGETLB>, C<IO::AIO::MAP_LOCKED>,
		1623	C<IO::AIO::MAP_NORESERVE>, C<IO::AIO::MAP_POPULATE> or
		1624	C<IO::AIO::MAP_NONBLOCK>
		1625
		1626	If C<$fh> is C<undef>, then a file descriptor of C<-1> is passed.
		1627
		1628	C<$offset> is the offset from the start of the file - it generally must be
		1629	a multiple of C<IO::AIO::PAGESIZE> and defaults to C<0>.
		1630
		1631	Example:
		1632
		1633	use Digest::MD5;
		1634	use IO::AIO;
		1635
		1636	open my $fh, "<verybigfile"
		1637	or die "$!";
		1638
		1639	IO::AIO::mmap my $data, -s $fh, IO::AIO::PROT_READ, IO::AIO::MAP_SHARED, $fh
		1640	or die "verybigfile: $!";
		1641
		1642	my $fast_md5 = md5 $data;
		1643
		1644	=item IO::AIO::munmap $scalar
		1645
		1646	Removes a previous mmap and undefines the C<$scalar>.
		1647
		1648	=item IO::AIO::munlock $scalar, $offset = 0, $length = undef
		1649
		1650	Calls the C<munlock> function, undoing the effects of a previous
		1651	C<aio_mlock> call (see its description for details).
		1652
		1653	=item IO::AIO::munlockall
		1654
		1655	Calls the C<munlockall> function.
		1656
		1657	On systems that do not implement C<munlockall>, this function returns
		1658	ENOSYS, otherwise the return value of C<munlockall>.
		1659
		1660	=back
		1661
1101	=cut	1662	=cut
1102		1663
1103	# support function to convert a fd into a perl filehandle
1104	sub _fd2fh {
1105	return undef if $_[0] < 0;
1106
1107	# try to generate nice filehandles
1108	my $sym = "IO::AIO::fd#$_[0]";
1109	local *$sym;
1110
1111	open *$sym, "+<&=$_[0]" # usually works under any unix
1112	or open *$sym, "<&=$_[0]" # cygwin needs this
1113	or open *$sym, ">&=$_[0]" # or this
1114	or return undef;
1115
1116	*$sym
1117	}
1118
1119	min_parallel 8;	1664	min_parallel 8;
1120		1665
1121	END { flush }	1666	END { flush }
1122		1667
1123	1;	1668	1;
		1669
		1670	=head1 EVENT LOOP INTEGRATION
		1671
		1672	It is recommended to use L<AnyEvent::AIO> to integrate IO::AIO
		1673	automatically into many event loops:
		1674
		1675	# AnyEvent integration (EV, Event, Glib, Tk, POE, urxvt, pureperl...)
		1676	use AnyEvent::AIO;
		1677
		1678	You can also integrate IO::AIO manually into many event loops, here are
		1679	some examples of how to do this:
		1680
		1681	# EV integration
		1682	my $aio_w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb;
		1683
		1684	# Event integration
		1685	Event->io (fd => IO::AIO::poll_fileno,
		1686	poll => 'r',
		1687	cb => \&IO::AIO::poll_cb);
		1688
		1689	# Glib/Gtk2 integration
		1690	add_watch Glib::IO IO::AIO::poll_fileno,
		1691	in => sub { IO::AIO::poll_cb; 1 };
		1692
		1693	# Tk integration
		1694	Tk::Event::IO->fileevent (IO::AIO::poll_fileno, "",
		1695	readable => \&IO::AIO::poll_cb);
		1696
		1697	# Danga::Socket integration
		1698	Danga::Socket->AddOtherFds (IO::AIO::poll_fileno =>
		1699	\&IO::AIO::poll_cb);
1124		1700
1125	=head2 FORK BEHAVIOUR	1701	=head2 FORK BEHAVIOUR
1126		1702
1127	This module should do "the right thing" when the process using it forks:	1703	This module should do "the right thing" when the process using it forks:
1128		1704
…		…
1146	bytes of memory. In addition, stat requests need a stat buffer (possibly	1722	bytes of memory. In addition, stat requests need a stat buffer (possibly
1147	a few hundred bytes), readdir requires a result buffer and so on. Perl	1723	a few hundred bytes), readdir requires a result buffer and so on. Perl
1148	scalars and other data passed into aio requests will also be locked and	1724	scalars and other data passed into aio requests will also be locked and
1149	will consume memory till the request has entered the done state.	1725	will consume memory till the request has entered the done state.
1150		1726
1151	This is now awfully much, so queuing lots of requests is not usually a	1727	This is not awfully much, so queuing lots of requests is not usually a
1152	problem.	1728	problem.
1153		1729
1154	Per-thread usage:	1730	Per-thread usage:
1155		1731
1156	In the execution phase, some aio requests require more memory for	1732	In the execution phase, some aio requests require more memory for
…		…
1161		1737
1162	Known bugs will be fixed in the next release.	1738	Known bugs will be fixed in the next release.
1163		1739
1164	=head1 SEE ALSO	1740	=head1 SEE ALSO
1165		1741
1166	L<Coro::AIO>.	1742	L<AnyEvent::AIO> for easy integration into event loops, L<Coro::AIO> for a
		1743	more natural syntax.
1167		1744
1168	=head1 AUTHOR	1745	=head1 AUTHOR
1169		1746
1170	Marc Lehmann <schmorp@schmorp.de>	1747	Marc Lehmann <schmorp@schmorp.de>
1171	http://home.schmorp.de/	1748	http://home.schmorp.de/

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