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Revision 1.110 by root, Sun Jul 8 09:09:34 2007 UTC vs.
Revision 1.208 by root, Mon Sep 26 20:19:08 2011 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
…		…
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	47	While most of this works on all types of file descriptors (for
68	example sockets), using these functions on file descriptors that	48	example sockets), using these functions on file descriptors that
69	support nonblocking operation (again, sockets, pipes etc.) is very	49	support nonblocking operation (again, sockets, pipes etc.) is
70	inefficient. Use an event loop for that (such as the L<Event|Event>	50	very inefficient. Use an event loop for that (such as the L<EV>
71	module): IO::AIO will naturally fit into such an event loop itself.	51	module): IO::AIO will naturally fit into such an event loop itself.
72		52
73	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
74	requests and signal their completion. You don't need thread support	54	requests and signal their completion. You don't need thread support
75	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
…		…
85	yourself, always call C<poll_cb> from within the same thread, or never	65	yourself, always call C<poll_cb> from within the same thread, or never
86	call C<poll_cb> (or other C<aio_> functions) recursively.	66	call C<poll_cb> (or other C<aio_> functions) recursively.
87		67
88	=head2 EXAMPLE	68	=head2 EXAMPLE
89		69
90	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
91	F</etc/passwd> asynchronously:	71	F</etc/passwd> asynchronously:
92		72
93	use Fcntl;	73	use Fcntl;
94	use Event;	74	use EV;
95	use IO::AIO;	75	use IO::AIO;
96		76
97	# register the IO::AIO callback with Event	77	# register the IO::AIO callback with EV
98	Event->io (fd => IO::AIO::poll_fileno,	78	my $aio_w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb;
99	poll => 'r',
100	cb => \&IO::AIO::poll_cb);
101		79
102	# queue the request to open /etc/passwd	80	# queue the request to open /etc/passwd
103	aio_open "/etc/passwd", O_RDONLY, 0, sub {	81	aio_open "/etc/passwd", IO::AIO::O_RDONLY, 0, sub {
104	my $fh = shift	82	my $fh = shift
105	or die "error while opening: $!";	83	or die "error while opening: $!";
106		84
107	# stat'ing filehandles is generally non-blocking	85	# stat'ing filehandles is generally non-blocking
108	my $size = -s $fh;	86	my $size = -s $fh;
…		…
117		95
118	# file contents now in $contents	96	# file contents now in $contents
119	print $contents;	97	print $contents;
120		98
121	# exit event loop and program	99	# exit event loop and program
122	Event::unloop;	100	EV::unloop;
123	};	101	};
124	};	102	};
125		103
126	# possibly queue up other requests, or open GUI windows,	104	# possibly queue up other requests, or open GUI windows,
127	# check for sockets etc. etc.	105	# check for sockets etc. etc.
128		106
129	# process events as long as there are some:	107	# process events as long as there are some:
130	Event::loop;	108	EV::loop;
131		109
132	=head1 REQUEST ANATOMY AND LIFETIME	110	=head1 REQUEST ANATOMY AND LIFETIME
133		111
134	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
135	directly visible to Perl.	113	directly visible to Perl.
…		…
183		161
184	=cut	162	=cut
185		163
186	package IO::AIO;	164	package IO::AIO;
187		165
188	no warnings;	166	use Carp ();
189	use strict 'vars';	167
		168	use common::sense;
190		169
191	use base 'Exporter';	170	use base 'Exporter';
192		171
193	BEGIN {	172	BEGIN {
194	our $VERSION = '2.4';	173	our $VERSION = '4.0';
195		174
196	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
197	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
198	aio_readlink aio_fsync aio_fdatasync aio_readahead aio_rename aio_link	177	aio_scandir aio_symlink aio_readlink aio_realpath aio_sync
		178	aio_fsync aio_syncfs aio_fdatasync aio_sync_file_range aio_fallocate
		179	aio_pathsync aio_readahead
		180	aio_rename aio_link aio_move aio_copy aio_group
199	aio_move aio_copy aio_group aio_nop aio_mknod aio_load aio_rmtree aio_mkdir	181	aio_nop aio_mknod aio_load aio_rmtree aio_mkdir aio_chown
200	aio_chown aio_chmod aio_utime aio_truncate);	182	aio_chmod aio_utime aio_truncate
		183	aio_msync aio_mtouch aio_mlock aio_mlockall
		184	aio_statvfs
		185	aio_wd);
		186
201	our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice aio_block));	187	our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice));
202	our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush	188	our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush
203	min_parallel max_parallel max_idle	189	min_parallel max_parallel max_idle idle_timeout
204	nreqs nready npending nthreads	190	nreqs nready npending nthreads
205	max_poll_time max_poll_reqs);	191	max_poll_time max_poll_reqs
		192	sendfile fadvise madvise
		193	mmap munmap munlock munlockall);
		194
		195	push @AIO_REQ, qw(aio_busy); # not exported
206		196
207	@IO::AIO::GRP::ISA = 'IO::AIO::REQ';	197	@IO::AIO::GRP::ISA = 'IO::AIO::REQ';
208		198
209	require XSLoader;	199	require XSLoader;
210	XSLoader::load ("IO::AIO", $VERSION);	200	XSLoader::load ("IO::AIO", $VERSION);
211	}	201	}
212		202
213	=head1 FUNCTIONS	203	=head1 FUNCTIONS
		204
		205	=head2 QUICK OVERVIEW
		206
		207	This section simply lists the prototypes of the most important functions
		208	for quick reference. See the following sections for function-by-function
		209	documentation.
		210
		211	aio_wd $pathname, $callback->($wd)
		212	aio_open $pathname, $flags, $mode, $callback->($fh)
		213	aio_close $fh, $callback->($status)
		214	aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
		215	aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
		216	aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval)
		217	aio_readahead $fh,$offset,$length, $callback->($retval)
		218	aio_stat $fh_or_path, $callback->($status)
		219	aio_lstat $fh, $callback->($status)
		220	aio_statvfs $fh_or_path, $callback->($statvfs)
		221	aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
		222	aio_chown $fh_or_path, $uid, $gid, $callback->($status)
		223	aio_truncate $fh_or_path, $offset, $callback->($status)
		224	aio_chmod $fh_or_path, $mode, $callback->($status)
		225	aio_unlink $pathname, $callback->($status)
		226	aio_mknod $path, $mode, $dev, $callback->($status)
		227	aio_link $srcpath, $dstpath, $callback->($status)
		228	aio_symlink $srcpath, $dstpath, $callback->($status)
		229	aio_readlink $path, $callback->($link)
		230	aio_realpath $path, $callback->($link)
		231	aio_rename $srcpath, $dstpath, $callback->($status)
		232	aio_mkdir $pathname, $mode, $callback->($status)
		233	aio_rmdir $pathname, $callback->($status)
		234	aio_readdir $pathname, $callback->($entries)
		235	aio_readdirx $pathname, $flags, $callback->($entries, $flags)
		236	IO::AIO::READDIR_DENTS IO::AIO::READDIR_DIRS_FIRST
		237	IO::AIO::READDIR_STAT_ORDER IO::AIO::READDIR_FOUND_UNKNOWN
		238	aio_load $path, $data, $callback->($status)
		239	aio_copy $srcpath, $dstpath, $callback->($status)
		240	aio_move $srcpath, $dstpath, $callback->($status)
		241	aio_scandir $path, $maxreq, $callback->($dirs, $nondirs)
		242	aio_rmtree $path, $callback->($status)
		243	aio_sync $callback->($status)
		244	aio_syncfs $fh, $callback->($status)
		245	aio_fsync $fh, $callback->($status)
		246	aio_fdatasync $fh, $callback->($status)
		247	aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status)
		248	aio_pathsync $path, $callback->($status)
		249	aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
		250	aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
		251	aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status)
		252	aio_mlockall $flags, $callback->($status)
		253	aio_group $callback->(...)
		254	aio_nop $callback->()
		255
		256	$prev_pri = aioreq_pri [$pri]
		257	aioreq_nice $pri_adjust
		258
		259	IO::AIO::poll_wait
		260	IO::AIO::poll_cb
		261	IO::AIO::poll
		262	IO::AIO::flush
		263	IO::AIO::max_poll_reqs $nreqs
		264	IO::AIO::max_poll_time $seconds
		265	IO::AIO::min_parallel $nthreads
		266	IO::AIO::max_parallel $nthreads
		267	IO::AIO::max_idle $nthreads
		268	IO::AIO::idle_timeout $seconds
		269	IO::AIO::max_outstanding $maxreqs
		270	IO::AIO::nreqs
		271	IO::AIO::nready
		272	IO::AIO::npending
		273
		274	IO::AIO::sendfile $ofh, $ifh, $offset, $count
		275	IO::AIO::fadvise $fh, $offset, $len, $advice
		276	IO::AIO::madvise $scalar, $offset, $length, $advice
		277	IO::AIO::mprotect $scalar, $offset, $length, $protect
		278	IO::AIO::munlock $scalar, $offset = 0, $length = undef
		279	IO::AIO::munlockall
214		280
215	=head2 AIO REQUEST FUNCTIONS	281	=head2 AIO REQUEST FUNCTIONS
216		282
217	All the C<aio_*> calls are more or less thin wrappers around the syscall	283	All the C<aio_*> calls are more or less thin wrappers around the syscall
218	with the same name (sans C<aio_>). The arguments are similar or identical,	284	with the same name (sans C<aio_>). The arguments are similar or identical,
219	and they all accept an additional (and optional) C<$callback> argument	285	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	286	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	287	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	288	perl, which usually delivers "false") as its sole argument after the given
223	syscall has been executed asynchronously.	289	syscall has been executed asynchronously.
224		290
225	All functions expecting a filehandle keep a copy of the filehandle	291	All functions expecting a filehandle keep a copy of the filehandle
226	internally until the request has finished.	292	internally until the request has finished.
227		293
…		…
241	your pathnames to the locale (or other) encoding in effect in the user	307	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)	308	environment, d) use Glib::filename_from_unicode on unicode filenames or e)
243	use something else to ensure your scalar has the correct contents.	309	use something else to ensure your scalar has the correct contents.
244		310
245	This works, btw. independent of the internal UTF-8 bit, which IO::AIO	311	This works, btw. independent of the internal UTF-8 bit, which IO::AIO
246	handles correctly wether it is set or not.	312	handles correctly whether it is set or not.
247		313
248	=over 4	314	=over 4
249		315
250	=item $prev_pri = aioreq_pri [$pri]	316	=item $prev_pri = aioreq_pri [$pri]
251		317
…		…
298	by the umask in effect then the request is being executed, so better never	364	by the umask in effect then the request is being executed, so better never
299	change the umask.	365	change the umask.
300		366
301	Example:	367	Example:
302		368
303	aio_open "/etc/passwd", O_RDONLY, 0, sub {	369	aio_open "/etc/passwd", IO::AIO::O_RDONLY, 0, sub {
304	if ($_[0]) {	370	if ($_[0]) {
305	print "open successful, fh is $_[0]\n";	371	print "open successful, fh is $_[0]\n";
306	...	372	...
307	} else {	373	} else {
308	die "open failed: $!\n";	374	die "open failed: $!\n";
309	}	375	}
310	};	376	};
311		377
		378	In addition to all the common open modes/flags (C<O_RDONLY>, C<O_WRONLY>,
		379	C<O_RDWR>, C<O_CREAT>, C<O_TRUNC>, C<O_EXCL> and C<O_APPEND>), the
		380	following POSIX and non-POSIX constants are available (missing ones on
		381	your system are, as usual, C<0>):
		382
		383	C<O_ASYNC>, C<O_DIRECT>, C<O_NOATIME>, C<O_CLOEXEC>, C<O_NOCTTY>, C<O_NOFOLLOW>,
		384	C<O_NONBLOCK>, C<O_EXEC>, C<O_SEARCH>, C<O_DIRECTORY>, C<O_DSYNC>,
		385	C<O_RSYNC>, C<O_SYNC> and C<O_TTY_INIT>.
		386
312		387
313	=item aio_close $fh, $callback->($status)	388	=item aio_close $fh, $callback->($status)
314		389
315	Asynchronously close a file and call the callback with the result	390	Asynchronously close a file and call the callback with the result
316	code. I<WARNING:> although accepted, you should not pass in a perl	391	code.
317	filehandle here, as perl will likely close the file descriptor another
318	time when the filehandle is destroyed. Normally, you can safely call perls
319	C<close> or just let filehandles go out of scope.
320		392
321	This is supposed to be a bug in the API, so that might change. It's	393	Unfortunately, you can't do this to perl. Perl I<insists> very strongly on
322	therefore best to avoid this function.	394	closing the file descriptor associated with the filehandle itself.
323		395
		396	Therefore, C<aio_close> will not close the filehandle - instead it will
		397	use dup2 to overwrite the file descriptor with the write-end of a pipe
		398	(the pipe fd will be created on demand and will be cached).
		399
		400	Or in other words: the file descriptor will be closed, but it will not be
		401	free for reuse until the perl filehandle is closed.
		402
		403	=cut
324		404
325	=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)	405	=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
326		406
327	=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)	407	=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
328		408
329	Reads or writes C<$length> bytes from the specified C<$fh> and C<$offset>	409	Reads or writes C<$length> bytes from or to the specified C<$fh> and
330	into the scalar given by C<$data> and offset C<$dataoffset> and calls the	410	C<$offset> into the scalar given by C<$data> and offset C<$dataoffset>
331	callback without the actual number of bytes read (or -1 on error, just	411	and calls the callback without the actual number of bytes read (or -1 on
332	like the syscall).	412	error, just like the syscall).
333		413
		414	C<aio_read> will, like C<sysread>, shrink or grow the C<$data> scalar to
		415	offset plus the actual number of bytes read.
		416
334	If C<$offset> is undefined, then the current file offset will be used (and	417	If C<$offset> is undefined, then the current file descriptor offset will
335	updated), otherwise the file offset will not be changed by these calls.	418	be used (and updated), otherwise the file descriptor offset will not be
		419	changed by these calls.
336		420
337	If C<$length> is undefined in C<aio_write>, use the remaining length of C<$data>.	421	If C<$length> is undefined in C<aio_write>, use the remaining length of
		422	C<$data>.
338		423
339	If C<$dataoffset> is less than zero, it will be counted from the end of	424	If C<$dataoffset> is less than zero, it will be counted from the end of
340	C<$data>.	425	C<$data>.
341		426
342	The C<$data> scalar I<MUST NOT> be modified in any way while the request	427	The C<$data> scalar I<MUST NOT> be modified in any way while the request
…		…
356		441
357	Tries to copy C<$length> bytes from C<$in_fh> to C<$out_fh>. It starts	442	Tries to copy C<$length> bytes from C<$in_fh> to C<$out_fh>. It starts
358	reading at byte offset C<$in_offset>, and starts writing at the current	443	reading at byte offset C<$in_offset>, and starts writing at the current
359	file offset of C<$out_fh>. Because of that, it is not safe to issue more	444	file offset of C<$out_fh>. Because of that, it is not safe to issue more
360	than one C<aio_sendfile> per C<$out_fh>, as they will interfere with each	445	than one C<aio_sendfile> per C<$out_fh>, as they will interfere with each
361	other.	446	other. The same C<$in_fh> works fine though, as this function does not
		447	move or use the file offset of C<$in_fh>.
362		448
		449	Please note that C<aio_sendfile> can read more bytes from C<$in_fh> than
		450	are written, and there is no way to find out how many more bytes have been
		451	read from C<aio_sendfile> alone, as C<aio_sendfile> only provides the
		452	number of bytes written to C<$out_fh>. Only if the result value equals
		453	C<$length> one can assume that C<$length> bytes have been read.
		454
		455	Unlike with other C<aio_> functions, it makes a lot of sense to use
		456	C<aio_sendfile> on non-blocking sockets, as long as one end (typically
		457	the C<$in_fh>) is a file - the file I/O will then be asynchronous, while
		458	the socket I/O will be non-blocking. Note, however, that you can run
		459	into a trap where C<aio_sendfile> reads some data with readahead, then
		460	fails to write all data, and when the socket is ready the next time, the
		461	data in the cache is already lost, forcing C<aio_sendfile> to again hit
		462	the disk. Explicit C<aio_read> + C<aio_write> let's you better control
		463	resource usage.
		464
363	This call tries to make use of a native C<sendfile> syscall to provide	465	This call tries to make use of a native C<sendfile>-like syscall to
364	zero-copy operation. For this to work, C<$out_fh> should refer to a	466	provide zero-copy operation. For this to work, C<$out_fh> should refer to
365	socket, and C<$in_fh> should refer to mmap'able file.	467	a socket, and C<$in_fh> should refer to an mmap'able file.
366		468
367	If the native sendfile call fails or is not implemented, it will be	469	If a native sendfile cannot be found or it fails with C<ENOSYS>,
368	emulated, so you can call C<aio_sendfile> on any type of filehandle	470	C<EINVAL>, C<ENOTSUP>, C<EOPNOTSUPP>, C<EAFNOSUPPORT>, C<EPROTOTYPE> or
		471	C<ENOTSOCK>, it will be emulated, so you can call C<aio_sendfile> on any
369	regardless of the limitations of the operating system.	472	type of filehandle regardless of the limitations of the operating system.
370		473
371	Please note, however, that C<aio_sendfile> can read more bytes from	474	As native sendfile syscalls (as practically any non-POSIX interface hacked
372	C<$in_fh> than are written, and there is no way to find out how many	475	together in a hurry to improve benchmark numbers) tend to be rather buggy
373	bytes have been read from C<aio_sendfile> alone, as C<aio_sendfile> only	476	on many systems, this implementation tries to work around some known bugs
374	provides the number of bytes written to C<$out_fh>. Only if the result	477	in Linux and FreeBSD kernels (probably others, too), but that might fail,
375	value equals C<$length> one can assume that C<$length> bytes have been	478	so you really really should check the return value of C<aio_sendfile> -
376	read.	479	fewre bytes than expected might have been transferred.
377		480
378		481
379	=item aio_readahead $fh,$offset,$length, $callback->($retval)	482	=item aio_readahead $fh,$offset,$length, $callback->($retval)
380		483
381	C<aio_readahead> populates the page cache with data from a file so that	484	C<aio_readahead> populates the page cache with data from a file so that
…		…
404		507
405	Currently, the stats are always 64-bit-stats, i.e. instead of returning an	508	Currently, the stats are always 64-bit-stats, i.e. instead of returning an
406	error when stat'ing a large file, the results will be silently truncated	509	error when stat'ing a large file, the results will be silently truncated
407	unless perl itself is compiled with large file support.	510	unless perl itself is compiled with large file support.
408		511
		512	To help interpret the mode and dev/rdev stat values, IO::AIO offers the
		513	following constants and functions (if not implemented, the constants will
		514	be C<0> and the functions will either C<croak> or fall back on traditional
		515	behaviour).
		516
		517	C<S_IFMT>, C<S_IFIFO>, C<S_IFCHR>, C<S_IFBLK>, C<S_IFLNK>, C<S_IFREG>,
		518	C<S_IFDIR>, C<S_IFWHT>, C<S_IFSOCK>, C<IO::AIO::major $dev_t>,
		519	C<IO::AIO::minor $dev_t>, C<IO::AIO::makedev $major, $minor>.
		520
409	Example: Print the length of F</etc/passwd>:	521	Example: Print the length of F</etc/passwd>:
410		522
411	aio_stat "/etc/passwd", sub {	523	aio_stat "/etc/passwd", sub {
412	$_[0] and die "stat failed: $!";	524	$_[0] and die "stat failed: $!";
413	print "size is ", -s _, "\n";	525	print "size is ", -s _, "\n";
414	};	526	};
415		527
416		528
		529	=item aio_statvfs $fh_or_path, $callback->($statvfs)
		530
		531	Works like the POSIX C<statvfs> or C<fstatvfs> syscalls, depending on
		532	whether a file handle or path was passed.
		533
		534	On success, the callback is passed a hash reference with the following
		535	members: C<bsize>, C<frsize>, C<blocks>, C<bfree>, C<bavail>, C<files>,
		536	C<ffree>, C<favail>, C<fsid>, C<flag> and C<namemax>. On failure, C<undef>
		537	is passed.
		538
		539	The following POSIX IO::AIO::ST_* constants are defined: C<ST_RDONLY> and
		540	C<ST_NOSUID>.
		541
		542	The following non-POSIX IO::AIO::ST_* flag masks are defined to
		543	their correct value when available, or to C<0> on systems that do
		544	not support them: C<ST_NODEV>, C<ST_NOEXEC>, C<ST_SYNCHRONOUS>,
		545	C<ST_MANDLOCK>, C<ST_WRITE>, C<ST_APPEND>, C<ST_IMMUTABLE>, C<ST_NOATIME>,
		546	C<ST_NODIRATIME> and C<ST_RELATIME>.
		547
		548	Example: stat C</wd> and dump out the data if successful.
		549
		550	aio_statvfs "/wd", sub {
		551	my $f = $_[0]
		552	or die "statvfs: $!";
		553
		554	use Data::Dumper;
		555	say Dumper $f;
		556	};
		557
		558	# result:
		559	{
		560	bsize => 1024,
		561	bfree => 4333064312,
		562	blocks => 10253828096,
		563	files => 2050765568,
		564	flag => 4096,
		565	favail => 2042092649,
		566	bavail => 4333064312,
		567	ffree => 2042092649,
		568	namemax => 255,
		569	frsize => 1024,
		570	fsid => 1810
		571	}
		572
		573
417	=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status)	574	=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
418		575
419	Works like perl's C<utime> function (including the special case of $atime	576	Works like perl's C<utime> function (including the special case of $atime
420	and $mtime being undef). Fractional times are supported if the underlying	577	and $mtime being undef). Fractional times are supported if the underlying
421	syscalls support them.	578	syscalls support them.
…		…
469		626
470	The only (POSIX-) portable way of calling this function is:	627	The only (POSIX-) portable way of calling this function is:
471		628
472	aio_mknod $path, IO::AIO::S_IFIFO | $mode, 0, sub { ...	629	aio_mknod $path, IO::AIO::S_IFIFO | $mode, 0, sub { ...
473		630
		631	See C<aio_stat> for info about some potentially helpful extra constants
		632	and functions.
474		633
475	=item aio_link $srcpath, $dstpath, $callback->($status)	634	=item aio_link $srcpath, $dstpath, $callback->($status)
476		635
477	Asynchronously create a new link to the existing object at C<$srcpath> at	636	Asynchronously create a new link to the existing object at C<$srcpath> at
478	the path C<$dstpath> and call the callback with the result code.	637	the path C<$dstpath> and call the callback with the result code.
…		…
489	Asynchronously read the symlink specified by C<$path> and pass it to	648	Asynchronously read the symlink specified by C<$path> and pass it to
490	the callback. If an error occurs, nothing or undef gets passed to the	649	the callback. If an error occurs, nothing or undef gets passed to the
491	callback.	650	callback.
492		651
493		652
		653	=item aio_realpath $path, $callback->($path)
		654
		655	Asynchronously make the path absolute and resolve any symlinks in
		656	C<$path>. The resulting path only consists of directories (Same as
		657	L<Cwd::realpath>).
		658
		659	This request can be used to get the absolute path of the current working
		660	directory by passing it a path of F<.> (a single dot).
		661
		662
494	=item aio_rename $srcpath, $dstpath, $callback->($status)	663	=item aio_rename $srcpath, $dstpath, $callback->($status)
495		664
496	Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as	665	Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as
497	rename(2) and call the callback with the result code.	666	rename(2) and call the callback with the result code.
498		667
…		…
514		683
515	Unlike the POSIX call of the same name, C<aio_readdir> reads an entire	684	Unlike the POSIX call of the same name, C<aio_readdir> reads an entire
516	directory (i.e. opendir + readdir + closedir). The entries will not be	685	directory (i.e. opendir + readdir + closedir). The entries will not be
517	sorted, and will B<NOT> include the C<.> and C<..> entries.	686	sorted, and will B<NOT> include the C<.> and C<..> entries.
518		687
519	The callback a single argument which is either C<undef> or an array-ref	688	The callback is passed a single argument which is either C<undef> or an
520	with the filenames.	689	array-ref with the filenames.
		690
		691
		692	=item aio_readdirx $pathname, $flags, $callback->($entries, $flags)
		693
		694	Quite similar to C<aio_readdir>, but the C<$flags> argument allows one to
		695	tune behaviour and output format. In case of an error, C<$entries> will be
		696	C<undef>.
		697
		698	The flags are a combination of the following constants, ORed together (the
		699	flags will also be passed to the callback, possibly modified):
		700
		701	=over 4
		702
		703	=item IO::AIO::READDIR_DENTS
		704
		705	When this flag is off, then the callback gets an arrayref consisting of
		706	names only (as with C<aio_readdir>), otherwise it gets an arrayref with
		707	C<[$name, $type, $inode]> arrayrefs, each describing a single directory
		708	entry in more detail.
		709
		710	C<$name> is the name of the entry.
		711
		712	C<$type> is one of the C<IO::AIO::DT_xxx> constants:
		713
		714	C<IO::AIO::DT_UNKNOWN>, C<IO::AIO::DT_FIFO>, C<IO::AIO::DT_CHR>, C<IO::AIO::DT_DIR>,
		715	C<IO::AIO::DT_BLK>, C<IO::AIO::DT_REG>, C<IO::AIO::DT_LNK>, C<IO::AIO::DT_SOCK>,
		716	C<IO::AIO::DT_WHT>.
		717
		718	C<IO::AIO::DT_UNKNOWN> means just that: readdir does not know. If you need to
		719	know, you have to run stat yourself. Also, for speed reasons, the C<$type>
		720	scalars are read-only: you can not modify them.
		721
		722	C<$inode> is the inode number (which might not be exact on systems with 64
		723	bit inode numbers and 32 bit perls). This field has unspecified content on
		724	systems that do not deliver the inode information.
		725
		726	=item IO::AIO::READDIR_DIRS_FIRST
		727
		728	When this flag is set, then the names will be returned in an order where
		729	likely directories come first, in optimal stat order. This is useful when
		730	you need to quickly find directories, or you want to find all directories
		731	while avoiding to stat() each entry.
		732
		733	If the system returns type information in readdir, then this is used
		734	to find directories directly. Otherwise, likely directories are names
		735	beginning with ".", or otherwise names with no dots, of which names with
		736	short names are tried first.
		737
		738	=item IO::AIO::READDIR_STAT_ORDER
		739
		740	When this flag is set, then the names will be returned in an order
		741	suitable for stat()'ing each one. That is, when you plan to stat()
		742	all files in the given directory, then the returned order will likely
		743	be fastest.
		744
		745	If both this flag and C<IO::AIO::READDIR_DIRS_FIRST> are specified, then
		746	the likely dirs come first, resulting in a less optimal stat order.
		747
		748	=item IO::AIO::READDIR_FOUND_UNKNOWN
		749
		750	This flag should not be set when calling C<aio_readdirx>. Instead, it
		751	is being set by C<aio_readdirx>, when any of the C<$type>'s found were
		752	C<IO::AIO::DT_UNKNOWN>. The absence of this flag therefore indicates that all
		753	C<$type>'s are known, which can be used to speed up some algorithms.
		754
		755	=back
521		756
522		757
523	=item aio_load $path, $data, $callback->($status)	758	=item aio_load $path, $data, $callback->($status)
524		759
525	This is a composite request that tries to fully load the given file into	760	This is a composite request that tries to fully load the given file into
526	memory. Status is the same as with aio_read.	761	memory. Status is the same as with aio_read.
527		762
528	=cut	763	=cut
529		764
530	sub aio_load($$;$) {	765	sub aio_load($$;$) {
531	aio_block {
532	my ($path, undef, $cb) = @_;	766	my ($path, undef, $cb) = @_;
533	my $data = \$_[1];	767	my $data = \$_[1];
534		768
535	my $pri = aioreq_pri;	769	my $pri = aioreq_pri;
536	my $grp = aio_group $cb;	770	my $grp = aio_group $cb;
		771
		772	aioreq_pri $pri;
		773	add $grp aio_open $path, O_RDONLY, 0, sub {
		774	my $fh = shift
		775	or return $grp->result (-1);
537		776
538	aioreq_pri $pri;	777	aioreq_pri $pri;
539	add $grp aio_open $path, O_RDONLY, 0, sub {
540	my $fh = shift
541	or return $grp->result (-1);
542
543	aioreq_pri $pri;
544	add $grp aio_read $fh, 0, (-s $fh), $$data, 0, sub {	778	add $grp aio_read $fh, 0, (-s $fh), $$data, 0, sub {
545	$grp->result ($_[0]);	779	$grp->result ($_[0]);
546	};
547	};	780	};
548
549	$grp
550	}	781	};
		782
		783	$grp
551	}	784	}
552		785
553	=item aio_copy $srcpath, $dstpath, $callback->($status)	786	=item aio_copy $srcpath, $dstpath, $callback->($status)
554		787
555	Try to copy the I<file> (directories not supported as either source or	788	Try to copy the I<file> (directories not supported as either source or
556	destination) from C<$srcpath> to C<$dstpath> and call the callback with	789	destination) from C<$srcpath> to C<$dstpath> and call the callback with
557	the C<0> (error) or C<-1> ok.	790	a status of C<0> (ok) or C<-1> (error, see C<$!>).
558		791
559	This is a composite request that it creates the destination file with	792	This is a composite request that creates the destination file with
560	mode 0200 and copies the contents of the source file into it using	793	mode 0200 and copies the contents of the source file into it using
561	C<aio_sendfile>, followed by restoring atime, mtime, access mode and	794	C<aio_sendfile>, followed by restoring atime, mtime, access mode and
562	uid/gid, in that order.	795	uid/gid, in that order.
563		796
564	If an error occurs, the partial destination file will be unlinked, if	797	If an error occurs, the partial destination file will be unlinked, if
…		…
566	errors are being ignored.	799	errors are being ignored.
567		800
568	=cut	801	=cut
569		802
570	sub aio_copy($$;$) {	803	sub aio_copy($$;$) {
571	aio_block {
572	my ($src, $dst, $cb) = @_;	804	my ($src, $dst, $cb) = @_;
573		805
574	my $pri = aioreq_pri;	806	my $pri = aioreq_pri;
575	my $grp = aio_group $cb;	807	my $grp = aio_group $cb;
576		808
577	aioreq_pri $pri;	809	aioreq_pri $pri;
578	add $grp aio_open $src, O_RDONLY, 0, sub {	810	add $grp aio_open $src, O_RDONLY, 0, sub {
579	if (my $src_fh = $_[0]) {	811	if (my $src_fh = $_[0]) {
580	my @stat = stat $src_fh;	812	my @stat = stat $src_fh; # hmm, might block over nfs?
581		813
582	aioreq_pri $pri;	814	aioreq_pri $pri;
583	add $grp aio_open $dst, O_CREAT | O_WRONLY | O_TRUNC, 0200, sub {	815	add $grp aio_open $dst, O_CREAT | O_WRONLY | O_TRUNC, 0200, sub {
584	if (my $dst_fh = $_[0]) {	816	if (my $dst_fh = $_[0]) {
585	aioreq_pri $pri;	817	aioreq_pri $pri;
586	add $grp aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub {	818	add $grp aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub {
587	if ($_[0] == $stat[7]) {	819	if ($_[0] == $stat[7]) {
588	$grp->result (0);	820	$grp->result (0);
589	close $src_fh;	821	close $src_fh;
590		822
591	# those should not normally block. should. should.
592	utime $stat[8], $stat[9], $dst;
593	chmod $stat[2] & 07777, $dst_fh;
594	chown $stat[4], $stat[5], $dst_fh;
595	close $dst_fh;
596	} else {	823	my $ch = sub {
597	$grp->result (-1);
598	close $src_fh;
599	close $dst_fh;
600
601	aioreq $pri;	824	aioreq_pri $pri;
		825	add $grp aio_chmod $dst_fh, $stat[2] & 07777, sub {
		826	aioreq_pri $pri;
		827	add $grp aio_chown $dst_fh, $stat[4], $stat[5], sub {
		828	aioreq_pri $pri;
602	add $grp aio_unlink $dst;	829	add $grp aio_close $dst_fh;
		830	}
		831	};
603	}	832	};
		833
		834	aioreq_pri $pri;
		835	add $grp aio_utime $dst_fh, $stat[8], $stat[9], sub {
		836	if ($_[0] < 0 && $! == ENOSYS) {
		837	aioreq_pri $pri;
		838	add $grp aio_utime $dst, $stat[8], $stat[9], $ch;
		839	} else {
		840	$ch->();
		841	}
		842	};
		843	} else {
		844	$grp->result (-1);
		845	close $src_fh;
		846	close $dst_fh;
		847
		848	aioreq $pri;
		849	add $grp aio_unlink $dst;
604	};	850	}
605	} else {
606	$grp->result (-1);
607	}	851	};
		852	} else {
		853	$grp->result (-1);
608	},	854	}
609
610	} else {
611	$grp->result (-1);
612	}	855	},
		856
		857	} else {
		858	$grp->result (-1);
613	};	859	}
614
615	$grp
616	}	860	};
		861
		862	$grp
617	}	863	}
618		864
619	=item aio_move $srcpath, $dstpath, $callback->($status)	865	=item aio_move $srcpath, $dstpath, $callback->($status)
620		866
621	Try to move the I<file> (directories not supported as either source or	867	Try to move the I<file> (directories not supported as either source or
622	destination) from C<$srcpath> to C<$dstpath> and call the callback with	868	destination) from C<$srcpath> to C<$dstpath> and call the callback with
623	the C<0> (error) or C<-1> ok.	869	a status of C<0> (ok) or C<-1> (error, see C<$!>).
624		870
625	This is a composite request that tries to rename(2) the file first. If	871	This is a composite request that tries to rename(2) the file first; if
626	rename files with C<EXDEV>, it copies the file with C<aio_copy> and, if	872	rename fails with C<EXDEV>, it copies the file with C<aio_copy> and, if
627	that is successful, unlinking the C<$srcpath>.	873	that is successful, unlinks the C<$srcpath>.
628		874
629	=cut	875	=cut
630		876
631	sub aio_move($$;$) {	877	sub aio_move($$;$) {
632	aio_block {
633	my ($src, $dst, $cb) = @_;	878	my ($src, $dst, $cb) = @_;
634		879
635	my $pri = aioreq_pri;	880	my $pri = aioreq_pri;
636	my $grp = aio_group $cb;	881	my $grp = aio_group $cb;
637		882
638	aioreq_pri $pri;	883	aioreq_pri $pri;
639	add $grp aio_rename $src, $dst, sub {	884	add $grp aio_rename $src, $dst, sub {
640	if ($_[0] && $! == EXDEV) {	885	if ($_[0] && $! == EXDEV) {
641	aioreq_pri $pri;	886	aioreq_pri $pri;
642	add $grp aio_copy $src, $dst, sub {	887	add $grp aio_copy $src, $dst, sub {
643	$grp->result ($_[0]);
644
645	if (!$_[0]) {
646	aioreq_pri $pri;
647	add $grp aio_unlink $src;
648	}
649	};
650	} else {
651	$grp->result ($_[0]);	888	$grp->result ($_[0]);
		889
		890	unless ($_[0]) {
		891	aioreq_pri $pri;
		892	add $grp aio_unlink $src;
		893	}
652	}	894	};
		895	} else {
		896	$grp->result ($_[0]);
653	};	897	}
654
655	$grp
656	}	898	};
		899
		900	$grp
657	}	901	}
658		902
659	=item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs)	903	=item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs)
660		904
661	Scans a directory (similar to C<aio_readdir>) but additionally tries to	905	Scans a directory (similar to C<aio_readdir>) but additionally tries to
…		…
681		925
682	Implementation notes.	926	Implementation notes.
683		927
684	The C<aio_readdir> cannot be avoided, but C<stat()>'ing every entry can.	928	The C<aio_readdir> cannot be avoided, but C<stat()>'ing every entry can.
685		929
		930	If readdir returns file type information, then this is used directly to
		931	find directories.
		932
686	After reading the directory, the modification time, size etc. of the	933	Otherwise, after reading the directory, the modification time, size etc.
687	directory before and after the readdir is checked, and if they match (and	934	of the directory before and after the readdir is checked, and if they
688	isn't the current time), the link count will be used to decide how many	935	match (and isn't the current time), the link count will be used to decide
689	entries are directories (if >= 2). Otherwise, no knowledge of the number	936	how many entries are directories (if >= 2). Otherwise, no knowledge of the
690	of subdirectories will be assumed.	937	number of subdirectories will be assumed.
691		938
692	Then entries will be sorted into likely directories (everything without	939	Then entries will be sorted into likely directories a non-initial dot
693	a non-initial dot currently) and likely non-directories (everything	940	currently) and likely non-directories (see C<aio_readdirx>). Then every
694	else). Then every entry plus an appended C</.> will be C<stat>'ed,	941	entry plus an appended C</.> will be C<stat>'ed, likely directories first,
695	likely directories first. If that succeeds, it assumes that the entry	942	in order of their inode numbers. If that succeeds, it assumes that the
696	is a directory or a symlink to directory (which will be checked	943	entry is a directory or a symlink to directory (which will be checked
697	seperately). This is often faster than stat'ing the entry itself because	944	separately). This is often faster than stat'ing the entry itself because
698	filesystems might detect the type of the entry without reading the inode	945	filesystems might detect the type of the entry without reading the inode
699	data (e.g. ext2fs filetype feature).	946	data (e.g. ext2fs filetype feature), even on systems that cannot return
		947	the filetype information on readdir.
700		948
701	If the known number of directories (link count - 2) has been reached, the	949	If the known number of directories (link count - 2) has been reached, the
702	rest of the entries is assumed to be non-directories.	950	rest of the entries is assumed to be non-directories.
703		951
704	This only works with certainty on POSIX (= UNIX) filesystems, which	952	This only works with certainty on POSIX (= UNIX) filesystems, which
…		…
709	directory counting heuristic.	957	directory counting heuristic.
710		958
711	=cut	959	=cut
712		960
713	sub aio_scandir($$;$) {	961	sub aio_scandir($$;$) {
714	aio_block {
715	my ($path, $maxreq, $cb) = @_;	962	my ($path, $maxreq, $cb) = @_;
716		963
717	my $pri = aioreq_pri;	964	my $pri = aioreq_pri;
718		965
719	my $grp = aio_group $cb;	966	my $grp = aio_group $cb;
720		967
721	$maxreq = 4 if $maxreq <= 0;	968	$maxreq = 4 if $maxreq <= 0;
722		969
723	# stat once	970	# stat once
		971	aioreq_pri $pri;
		972	add $grp aio_stat $path, sub {
		973	return $grp->result () if $_[0];
		974	my $now = time;
		975	my $hash1 = join ":", (stat _)[0,1,3,7,9];
		976
		977	# read the directory entries
724	aioreq_pri $pri;	978	aioreq_pri $pri;
725	add $grp aio_stat $path, sub {	979	add $grp aio_readdirx $path, READDIR_DIRS_FIRST, sub {
		980	my $entries = shift
726	return $grp->result () if $_[0];	981	or return $grp->result ();
727	my $now = time;
728	my $hash1 = join ":", (stat _)[0,1,3,7,9];
729		982
730	# read the directory entries	983	# stat the dir another time
731	aioreq_pri $pri;	984	aioreq_pri $pri;
732	add $grp aio_readdir $path, sub {
733	my $entries = shift
734	or return $grp->result ();
735
736	# stat the dir another time
737	aioreq_pri $pri;
738	add $grp aio_stat $path, sub {	985	add $grp aio_stat $path, sub {
739	my $hash2 = join ":", (stat _)[0,1,3,7,9];	986	my $hash2 = join ":", (stat _)[0,1,3,7,9];
740		987
741	my $ndirs;	988	my $ndirs;
742		989
743	# take the slow route if anything looks fishy	990	# take the slow route if anything looks fishy
744	if ($hash1 ne $hash2 or (stat _)[9] == $now) {	991	if ($hash1 ne $hash2 or (stat _)[9] == $now) {
745	$ndirs = -1;	992	$ndirs = -1;
746	} else {	993	} else {
747	# if nlink == 2, we are finished	994	# if nlink == 2, we are finished
748	# on non-posix-fs's, we rely on nlink < 2	995	# for non-posix-fs's, we rely on nlink < 2
749	$ndirs = (stat _)[3] - 2	996	$ndirs = (stat _)[3] - 2
750	or return $grp->result ([], $entries);	997	or return $grp->result ([], $entries);
751	}	998	}
752		999
753	# sort into likely dirs and likely nondirs
754	# dirs == files without ".", short entries first
755	$entries = [map $_->[0],
756	sort { $b->[1] cmp $a->[1] }
757	map [$_, sprintf "%s%04d", (/.\./ ? "1" : "0"), length],
758	@$entries];
759
760	my (@dirs, @nondirs);	1000	my (@dirs, @nondirs);
761		1001
762	my $statgrp = add $grp aio_group sub {	1002	my $statgrp = add $grp aio_group sub {
763	$grp->result (\@dirs, \@nondirs);	1003	$grp->result (\@dirs, \@nondirs);
764	};	1004	};
765		1005
766	limit $statgrp $maxreq;	1006	limit $statgrp $maxreq;
767	feed $statgrp sub {	1007	feed $statgrp sub {
768	return unless @$entries;	1008	return unless @$entries;
769	my $entry = pop @$entries;	1009	my $entry = shift @$entries;
770		1010
771	aioreq_pri $pri;	1011	aioreq_pri $pri;
772	add $statgrp aio_stat "$path/$entry/.", sub {	1012	add $statgrp aio_stat "$path/$entry/.", sub {
773	if ($_[0] < 0) {	1013	if ($_[0] < 0) {
774	push @nondirs, $entry;	1014	push @nondirs, $entry;
775	} else {	1015	} else {
776	# need to check for real directory	1016	# need to check for real directory
777	aioreq_pri $pri;	1017	aioreq_pri $pri;
778	add $statgrp aio_lstat "$path/$entry", sub {	1018	add $statgrp aio_lstat "$path/$entry", sub {
779	if (-d _) {	1019	if (-d _) {
780	push @dirs, $entry;	1020	push @dirs, $entry;
781		1021
782	unless (--$ndirs) {	1022	unless (--$ndirs) {
783	push @nondirs, @$entries;	1023	push @nondirs, @$entries;
784	feed $statgrp;	1024	feed $statgrp;
785	}
786	} else {
787	push @nondirs, $entry;
788	}	1025	}
		1026	} else {
		1027	push @nondirs, $entry;
789	}	1028	}
790	}	1029	}
791	};	1030	}
792	};	1031	};
793	};	1032	};
794	};	1033	};
795	};	1034	};
796
797	$grp
798	}	1035	};
		1036
		1037	$grp
799	}	1038	}
800		1039
801	=item aio_rmtree $path, $callback->($status)	1040	=item aio_rmtree $path, $callback->($status)
802		1041
803	Delete a directory tree starting (and including) C<$path>, return the	1042	Delete a directory tree starting (and including) C<$path>, return the
…		…
807		1046
808	=cut	1047	=cut
809		1048
810	sub aio_rmtree;	1049	sub aio_rmtree;
811	sub aio_rmtree($;$) {	1050	sub aio_rmtree($;$) {
812	aio_block {
813	my ($path, $cb) = @_;	1051	my ($path, $cb) = @_;
814		1052
815	my $pri = aioreq_pri;	1053	my $pri = aioreq_pri;
816	my $grp = aio_group $cb;	1054	my $grp = aio_group $cb;
817		1055
818	aioreq_pri $pri;	1056	aioreq_pri $pri;
819	add $grp aio_scandir $path, 0, sub {	1057	add $grp aio_scandir $path, 0, sub {
820	my ($dirs, $nondirs) = @_;	1058	my ($dirs, $nondirs) = @_;
821		1059
822	my $dirgrp = aio_group sub {	1060	my $dirgrp = aio_group sub {
823	add $grp aio_rmdir $path, sub {	1061	add $grp aio_rmdir $path, sub {
824	$grp->result ($_[0]);	1062	$grp->result ($_[0]);
825	};
826	};	1063	};
827
828	(aioreq_pri $pri), add $dirgrp aio_rmtree "$path/$_" for @$dirs;
829	(aioreq_pri $pri), add $dirgrp aio_unlink "$path/$_" for @$nondirs;
830
831	add $grp $dirgrp;
832	};	1064	};
833		1065
834	$grp	1066	(aioreq_pri $pri), add $dirgrp aio_rmtree "$path/$_" for @$dirs;
		1067	(aioreq_pri $pri), add $dirgrp aio_unlink "$path/$_" for @$nondirs;
		1068
		1069	add $grp $dirgrp;
835	}	1070	};
		1071
		1072	$grp
836	}	1073	}
		1074
		1075	=item aio_sync $callback->($status)
		1076
		1077	Asynchronously call sync and call the callback when finished.
837		1078
838	=item aio_fsync $fh, $callback->($status)	1079	=item aio_fsync $fh, $callback->($status)
839		1080
840	Asynchronously call fsync on the given filehandle and call the callback	1081	Asynchronously call fsync on the given filehandle and call the callback
841	with the fsync result code.	1082	with the fsync result code.
…		…
845	Asynchronously call fdatasync on the given filehandle and call the	1086	Asynchronously call fdatasync on the given filehandle and call the
846	callback with the fdatasync result code.	1087	callback with the fdatasync result code.
847		1088
848	If this call isn't available because your OS lacks it or it couldn't be	1089	If this call isn't available because your OS lacks it or it couldn't be
849	detected, it will be emulated by calling C<fsync> instead.	1090	detected, it will be emulated by calling C<fsync> instead.
		1091
		1092	=item aio_syncfs $fh, $callback->($status)
		1093
		1094	Asynchronously call the syncfs syscall to sync the filesystem associated
		1095	to the given filehandle and call the callback with the syncfs result
		1096	code. If syncfs is not available, calls sync(), but returns C<-1> and sets
		1097	errno to C<ENOSYS> nevertheless.
		1098
		1099	=item aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status)
		1100
		1101	Sync the data portion of the file specified by C<$offset> and C<$length>
		1102	to disk (but NOT the metadata), by calling the Linux-specific
		1103	sync_file_range call. If sync_file_range is not available or it returns
		1104	ENOSYS, then fdatasync or fsync is being substituted.
		1105
		1106	C<$flags> can be a combination of C<IO::AIO::SYNC_FILE_RANGE_WAIT_BEFORE>,
		1107	C<IO::AIO::SYNC_FILE_RANGE_WRITE> and
		1108	C<IO::AIO::SYNC_FILE_RANGE_WAIT_AFTER>: refer to the sync_file_range
		1109	manpage for details.
		1110
		1111	=item aio_pathsync $path, $callback->($status)
		1112
		1113	This request tries to open, fsync and close the given path. This is a
		1114	composite request intended to sync directories after directory operations
		1115	(E.g. rename). This might not work on all operating systems or have any
		1116	specific effect, but usually it makes sure that directory changes get
		1117	written to disc. It works for anything that can be opened for read-only,
		1118	not just directories.
		1119
		1120	Future versions of this function might fall back to other methods when
		1121	C<fsync> on the directory fails (such as calling C<sync>).
		1122
		1123	Passes C<0> when everything went ok, and C<-1> on error.
		1124
		1125	=cut
		1126
		1127	sub aio_pathsync($;$) {
		1128	my ($path, $cb) = @_;
		1129
		1130	my $pri = aioreq_pri;
		1131	my $grp = aio_group $cb;
		1132
		1133	aioreq_pri $pri;
		1134	add $grp aio_open $path, O_RDONLY, 0, sub {
		1135	my ($fh) = @_;
		1136	if ($fh) {
		1137	aioreq_pri $pri;
		1138	add $grp aio_fsync $fh, sub {
		1139	$grp->result ($_[0]);
		1140
		1141	aioreq_pri $pri;
		1142	add $grp aio_close $fh;
		1143	};
		1144	} else {
		1145	$grp->result (-1);
		1146	}
		1147	};
		1148
		1149	$grp
		1150	}
		1151
		1152	=item aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
		1153
		1154	This is a rather advanced IO::AIO call, which only works on mmap(2)ed
		1155	scalars (see the C<IO::AIO::mmap> function, although it also works on data
		1156	scalars managed by the L<Sys::Mmap> or L<Mmap> modules, note that the
		1157	scalar must only be modified in-place while an aio operation is pending on
		1158	it).
		1159
		1160	It calls the C<msync> function of your OS, if available, with the memory
		1161	area starting at C<$offset> in the string and ending C<$length> bytes
		1162	later. If C<$length> is negative, counts from the end, and if C<$length>
		1163	is C<undef>, then it goes till the end of the string. The flags can be
		1164	a combination of C<IO::AIO::MS_ASYNC>, C<IO::AIO::MS_INVALIDATE> and
		1165	C<IO::AIO::MS_SYNC>.
		1166
		1167	=item aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
		1168
		1169	This is a rather advanced IO::AIO call, which works best on mmap(2)ed
		1170	scalars.
		1171
		1172	It touches (reads or writes) all memory pages in the specified
		1173	range inside the scalar. All caveats and parameters are the same
		1174	as for C<aio_msync>, above, except for flags, which must be either
		1175	C<0> (which reads all pages and ensures they are instantiated) or
		1176	C<IO::AIO::MT_MODIFY>, which modifies the memory page s(by reading and
		1177	writing an octet from it, which dirties the page).
		1178
		1179	=item aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status)
		1180
		1181	This is a rather advanced IO::AIO call, which works best on mmap(2)ed
		1182	scalars.
		1183
		1184	It reads in all the pages of the underlying storage into memory (if any)
		1185	and locks them, so they are not getting swapped/paged out or removed.
		1186
		1187	If C<$length> is undefined, then the scalar will be locked till the end.
		1188
		1189	On systems that do not implement C<mlock>, this function returns C<-1>
		1190	and sets errno to C<ENOSYS>.
		1191
		1192	Note that the corresponding C<munlock> is synchronous and is
		1193	documented under L<MISCELLANEOUS FUNCTIONS>.
		1194
		1195	Example: open a file, mmap and mlock it - both will be undone when
		1196	C<$data> gets destroyed.
		1197
		1198	open my $fh, "<", $path or die "$path: $!";
		1199	my $data;
		1200	IO::AIO::mmap $data, -s $fh, IO::AIO::PROT_READ, IO::AIO::MAP_SHARED, $fh;
		1201	aio_mlock $data; # mlock in background
		1202
		1203	=item aio_mlockall $flags, $callback->($status)
		1204
		1205	Calls the C<mlockall> function with the given C<$flags> (a combination of
		1206	C<IO::AIO::MCL_CURRENT> and C<IO::AIO::MCL_FUTURE>).
		1207
		1208	On systems that do not implement C<mlockall>, this function returns C<-1>
		1209	and sets errno to C<ENOSYS>.
		1210
		1211	Note that the corresponding C<munlockall> is synchronous and is
		1212	documented under L<MISCELLANEOUS FUNCTIONS>.
		1213
		1214	Example: asynchronously lock all current and future pages into memory.
		1215
		1216	aio_mlockall IO::AIO::MCL_FUTURE;
850		1217
851	=item aio_group $callback->(...)	1218	=item aio_group $callback->(...)
852		1219
853	This is a very special aio request: Instead of doing something, it is a	1220	This is a very special aio request: Instead of doing something, it is a
854	container for other aio requests, which is useful if you want to bundle	1221	container for other aio requests, which is useful if you want to bundle
…		…
904	=item cancel $req	1271	=item cancel $req
905		1272
906	Cancels the request, if possible. Has the effect of skipping execution	1273	Cancels the request, if possible. Has the effect of skipping execution
907	when entering the B<execute> state and skipping calling the callback when	1274	when entering the B<execute> state and skipping calling the callback when
908	entering the the B<result> state, but will leave the request otherwise	1275	entering the the B<result> state, but will leave the request otherwise
909	untouched. That means that requests that currently execute will not be	1276	untouched (with the exception of readdir). That means that requests that
910	stopped and resources held by the request will not be freed prematurely.	1277	currently execute will not be stopped and resources held by the request
		1278	will not be freed prematurely.
911		1279
912	=item cb $req $callback->(...)	1280	=item cb $req $callback->(...)
913		1281
914	Replace (or simply set) the callback registered to the request.	1282	Replace (or simply set) the callback registered to the request.
915		1283
…		…
966	Their lifetime, simplified, looks like this: when they are empty, they	1334	Their lifetime, simplified, looks like this: when they are empty, they
967	will finish very quickly. If they contain only requests that are in the	1335	will finish very quickly. If they contain only requests that are in the
968	C<done> state, they will also finish. Otherwise they will continue to	1336	C<done> state, they will also finish. Otherwise they will continue to
969	exist.	1337	exist.
970		1338
971	That means after creating a group you have some time to add requests. And	1339	That means after creating a group you have some time to add requests
972	in the callbacks of those requests, you can add further requests to the	1340	(precisely before the callback has been invoked, which is only done within
973	group. And only when all those requests have finished will the the group	1341	the C<poll_cb>). And in the callbacks of those requests, you can add
974	itself finish.	1342	further requests to the group. And only when all those requests have
		1343	finished will the the group itself finish.
975		1344
976	=over 4	1345	=over 4
977		1346
978	=item add $grp ...	1347	=item add $grp ...
979		1348
…		…
988	=item $grp->cancel_subs	1357	=item $grp->cancel_subs
989		1358
990	Cancel all subrequests and clears any feeder, but not the group request	1359	Cancel all subrequests and clears any feeder, but not the group request
991	itself. Useful when you queued a lot of events but got a result early.	1360	itself. Useful when you queued a lot of events but got a result early.
992		1361
		1362	The group request will finish normally (you cannot add requests to the
		1363	group).
		1364
993	=item $grp->result (...)	1365	=item $grp->result (...)
994		1366
995	Set the result value(s) that will be passed to the group callback when all	1367	Set the result value(s) that will be passed to the group callback when all
996	subrequests have finished and set thre groups errno to the current value	1368	subrequests have finished and set the groups errno to the current value
997	of errno (just like calling C<errno> without an error number). By default,	1369	of errno (just like calling C<errno> without an error number). By default,
998	no argument will be passed and errno is zero.	1370	no argument will be passed and errno is zero.
999		1371
1000	=item $grp->errno ([$errno])	1372	=item $grp->errno ([$errno])
1001		1373
…		…
1012	=item feed $grp $callback->($grp)	1384	=item feed $grp $callback->($grp)
1013		1385
1014	Sets a feeder/generator on this group: every group can have an attached	1386	Sets a feeder/generator on this group: every group can have an attached
1015	generator that generates requests if idle. The idea behind this is that,	1387	generator that generates requests if idle. The idea behind this is that,
1016	although you could just queue as many requests as you want in a group,	1388	although you could just queue as many requests as you want in a group,
1017	this might starve other requests for a potentially long time. For	1389	this might starve other requests for a potentially long time. For example,
1018	example, C<aio_scandir> might generate hundreds of thousands C<aio_stat>	1390	C<aio_scandir> might generate hundreds of thousands C<aio_stat> requests,
1019	requests, delaying any later requests for a long time.	1391	delaying any later requests for a long time.
1020		1392
1021	To avoid this, and allow incremental generation of requests, you can	1393	To avoid this, and allow incremental generation of requests, you can
1022	instead a group and set a feeder on it that generates those requests. The	1394	instead a group and set a feeder on it that generates those requests. The
1023	feed callback will be called whenever there are few enough (see C<limit>,	1395	feed callback will be called whenever there are few enough (see C<limit>,
1024	below) requests active in the group itself and is expected to queue more	1396	below) requests active in the group itself and is expected to queue more
…		…
1028	not impose any limits).	1400	not impose any limits).
1029		1401
1030	If the feed does not queue more requests when called, it will be	1402	If the feed does not queue more requests when called, it will be
1031	automatically removed from the group.	1403	automatically removed from the group.
1032		1404
1033	If the feed limit is C<0>, it will be set to C<2> automatically.	1405	If the feed limit is C<0> when this method is called, it will be set to
		1406	C<2> automatically.
1034		1407
1035	Example:	1408	Example:
1036		1409
1037	# stat all files in @files, but only ever use four aio requests concurrently:	1410	# stat all files in @files, but only ever use four aio requests concurrently:
1038		1411
…		…
1050	Sets the feeder limit for the group: The feeder will be called whenever	1423	Sets the feeder limit for the group: The feeder will be called whenever
1051	the group contains less than this many requests.	1424	the group contains less than this many requests.
1052		1425
1053	Setting the limit to C<0> will pause the feeding process.	1426	Setting the limit to C<0> will pause the feeding process.
1054		1427
		1428	The default value for the limit is C<0>, but note that setting a feeder
		1429	automatically bumps it up to C<2>.
		1430
1055	=back	1431	=back
1056		1432
1057	=head2 SUPPORT FUNCTIONS	1433	=head2 SUPPORT FUNCTIONS
1058		1434
1059	=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION	1435	=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION
…		…
1061	=over 4	1437	=over 4
1062		1438
1063	=item $fileno = IO::AIO::poll_fileno	1439	=item $fileno = IO::AIO::poll_fileno
1064		1440
1065	Return the I<request result pipe file descriptor>. This filehandle must be	1441	Return the I<request result pipe file descriptor>. This filehandle must be
1066	polled for reading by some mechanism outside this module (e.g. Event or	1442	polled for reading by some mechanism outside this module (e.g. EV, Glib,
1067	select, see below or the SYNOPSIS). If the pipe becomes readable you have	1443	select and so on, see below or the SYNOPSIS). If the pipe becomes readable
1068	to call C<poll_cb> to check the results.	1444	you have to call C<poll_cb> to check the results.
1069		1445
1070	See C<poll_cb> for an example.	1446	See C<poll_cb> for an example.
1071		1447
1072	=item IO::AIO::poll_cb	1448	=item IO::AIO::poll_cb
1073		1449
1074	Process some outstanding events on the result pipe. You have to call this	1450	Process some outstanding events on the result pipe. You have to call
1075	regularly. Returns the number of events processed. Returns immediately	1451	this regularly. Returns C<0> if all events could be processed (or there
1076	when no events are outstanding. The amount of events processed depends on	1452	were no events to process), or C<-1> if it returned earlier for whatever
1077	the settings of C<IO::AIO::max_poll_req> and C<IO::AIO::max_poll_time>.	1453	reason. Returns immediately when no events are outstanding. The amount of
		1454	events processed depends on the settings of C<IO::AIO::max_poll_req> and
		1455	C<IO::AIO::max_poll_time>.
1078		1456
1079	If not all requests were processed for whatever reason, the filehandle	1457	If not all requests were processed for whatever reason, the filehandle
1080	will still be ready when C<poll_cb> returns.	1458	will still be ready when C<poll_cb> returns, so normally you don't have to
		1459	do anything special to have it called later.
		1460
		1461	Apart from calling C<IO::AIO::poll_cb> when the event filehandle becomes
		1462	ready, it can be beneficial to call this function from loops which submit
		1463	a lot of requests, to make sure the results get processed when they become
		1464	available and not just when the loop is finished and the event loop takes
		1465	over again. This function returns very fast when there are no outstanding
		1466	requests.
1081		1467
1082	Example: Install an Event watcher that automatically calls	1468	Example: Install an Event watcher that automatically calls
1083	IO::AIO::poll_cb with high priority:	1469	IO::AIO::poll_cb with high priority (more examples can be found in the
		1470	SYNOPSIS section, at the top of this document):
1084		1471
1085	Event->io (fd => IO::AIO::poll_fileno,	1472	Event->io (fd => IO::AIO::poll_fileno,
1086	poll => 'r', async => 1,	1473	poll => 'r', async => 1,
1087	cb => \&IO::AIO::poll_cb);	1474	cb => \&IO::AIO::poll_cb);
		1475
		1476	=item IO::AIO::poll_wait
		1477
		1478	If there are any outstanding requests and none of them in the result
		1479	phase, wait till the result filehandle becomes ready for reading (simply
		1480	does a C<select> on the filehandle. This is useful if you want to
		1481	synchronously wait for some requests to finish).
		1482
		1483	See C<nreqs> for an example.
		1484
		1485	=item IO::AIO::poll
		1486
		1487	Waits until some requests have been handled.
		1488
		1489	Returns the number of requests processed, but is otherwise strictly
		1490	equivalent to:
		1491
		1492	IO::AIO::poll_wait, IO::AIO::poll_cb
		1493
		1494	=item IO::AIO::flush
		1495
		1496	Wait till all outstanding AIO requests have been handled.
		1497
		1498	Strictly equivalent to:
		1499
		1500	IO::AIO::poll_wait, IO::AIO::poll_cb
		1501	while IO::AIO::nreqs;
1088		1502
1089	=item IO::AIO::max_poll_reqs $nreqs	1503	=item IO::AIO::max_poll_reqs $nreqs
1090		1504
1091	=item IO::AIO::max_poll_time $seconds	1505	=item IO::AIO::max_poll_time $seconds
1092		1506
…		…
1117	# use a low priority so other tasks have priority	1531	# use a low priority so other tasks have priority
1118	Event->io (fd => IO::AIO::poll_fileno,	1532	Event->io (fd => IO::AIO::poll_fileno,
1119	poll => 'r', nice => 1,	1533	poll => 'r', nice => 1,
1120	cb => &IO::AIO::poll_cb);	1534	cb => &IO::AIO::poll_cb);
1121		1535
1122	=item IO::AIO::poll_wait
1123
1124	If there are any outstanding requests and none of them in the result
1125	phase, wait till the result filehandle becomes ready for reading (simply
1126	does a C<select> on the filehandle. This is useful if you want to
1127	synchronously wait for some requests to finish).
1128
1129	See C<nreqs> for an example.
1130
1131	=item IO::AIO::poll
1132
1133	Waits until some requests have been handled.
1134
1135	Returns the number of requests processed, but is otherwise strictly
1136	equivalent to:
1137
1138	IO::AIO::poll_wait, IO::AIO::poll_cb
1139
1140	=item IO::AIO::flush
1141
1142	Wait till all outstanding AIO requests have been handled.
1143
1144	Strictly equivalent to:
1145
1146	IO::AIO::poll_wait, IO::AIO::poll_cb
1147	while IO::AIO::nreqs;
1148
1149	=back	1536	=back
1150		1537
1151	=head3 CONTROLLING THE NUMBER OF THREADS	1538	=head3 CONTROLLING THE NUMBER OF THREADS
1152		1539
1153	=over	1540	=over
…		…
1186		1573
1187	Under normal circumstances you don't need to call this function.	1574	Under normal circumstances you don't need to call this function.
1188		1575
1189	=item IO::AIO::max_idle $nthreads	1576	=item IO::AIO::max_idle $nthreads
1190		1577
1191	Limit the number of threads (default: 4) that are allowed to idle (i.e.,	1578	Limit the number of threads (default: 4) that are allowed to idle
1192	threads that did not get a request to process within 10 seconds). That	1579	(i.e., threads that did not get a request to process within the idle
1193	means if a thread becomes idle while C<$nthreads> other threads are also	1580	timeout (default: 10 seconds). That means if a thread becomes idle while
1194	idle, it will free its resources and exit.	1581	C<$nthreads> other threads are also idle, it will free its resources and
		1582	exit.
1195		1583
1196	This is useful when you allow a large number of threads (e.g. 100 or 1000)	1584	This is useful when you allow a large number of threads (e.g. 100 or 1000)
1197	to allow for extremely high load situations, but want to free resources	1585	to allow for extremely high load situations, but want to free resources
1198	under normal circumstances (1000 threads can easily consume 30MB of RAM).	1586	under normal circumstances (1000 threads can easily consume 30MB of RAM).
1199		1587
1200	The default is probably ok in most situations, especially if thread	1588	The default is probably ok in most situations, especially if thread
1201	creation is fast. If thread creation is very slow on your system you might	1589	creation is fast. If thread creation is very slow on your system you might
1202	want to use larger values.	1590	want to use larger values.
1203		1591
		1592	=item IO::AIO::idle_timeout $seconds
		1593
		1594	Sets the minimum idle timeout (default 10) after which worker threads are
		1595	allowed to exit. SEe C<IO::AIO::max_idle>.
		1596
1204	=item $oldmaxreqs = IO::AIO::max_outstanding $maxreqs	1597	=item IO::AIO::max_outstanding $maxreqs
		1598
		1599	Sets the maximum number of outstanding requests to C<$nreqs>. If
		1600	you do queue up more than this number of requests, the next call to
		1601	C<IO::AIO::poll_cb> (and other functions calling C<poll_cb>, such as
		1602	C<IO::AIO::flush> or C<IO::AIO::poll>) will block until the limit is no
		1603	longer exceeded.
		1604
		1605	In other words, this setting does not enforce a queue limit, but can be
		1606	used to make poll functions block if the limit is exceeded.
1205		1607
1206	This is a very bad function to use in interactive programs because it	1608	This is a very bad function to use in interactive programs because it
1207	blocks, and a bad way to reduce concurrency because it is inexact: Better	1609	blocks, and a bad way to reduce concurrency because it is inexact: Better
1208	use an C<aio_group> together with a feed callback.	1610	use an C<aio_group> together with a feed callback.
1209		1611
1210	Sets the maximum number of outstanding requests to C<$nreqs>. If you	1612	It's main use is in scripts without an event loop - when you want to stat
1211	to queue up more than this number of requests, the next call to the	1613	a lot of files, you can write somehting like this:
1212	C<poll_cb> (and C<poll_some> and other functions calling C<poll_cb>)
1213	function will block until the limit is no longer exceeded.
1214		1614
1215	The default value is very large, so there is no practical limit on the	1615	IO::AIO::max_outstanding 32;
1216	number of outstanding requests.
1217		1616
1218	You can still queue as many requests as you want. Therefore,	1617	for my $path (...) {
1219	C<max_oustsanding> is mainly useful in simple scripts (with low values) or	1618	aio_stat $path , ...;
1220	as a stop gap to shield against fatal memory overflow (with large values).	1619	IO::AIO::poll_cb;
		1620	}
		1621
		1622	IO::AIO::flush;
		1623
		1624	The call to C<poll_cb> inside the loop will normally return instantly, but
		1625	as soon as more thna C<32> reqeusts are in-flight, it will block until
		1626	some requests have been handled. This keeps the loop from pushing a large
		1627	number of C<aio_stat> requests onto the queue.
		1628
		1629	The default value for C<max_outstanding> is very large, so there is no
		1630	practical limit on the number of outstanding requests.
1221		1631
1222	=back	1632	=back
1223		1633
1224	=head3 STATISTICAL INFORMATION	1634	=head3 STATISTICAL INFORMATION
1225		1635
…		…
1245	Returns the number of requests currently in the pending state (executed,	1655	Returns the number of requests currently in the pending state (executed,
1246	but not yet processed by poll_cb).	1656	but not yet processed by poll_cb).
1247		1657
1248	=back	1658	=back
1249		1659
		1660	=head3 MISCELLANEOUS FUNCTIONS
		1661
		1662	IO::AIO implements some functions that might be useful, but are not
		1663	asynchronous.
		1664
		1665	=over 4
		1666
		1667	=item IO::AIO::sendfile $ofh, $ifh, $offset, $count
		1668
		1669	Calls the C<eio_sendfile_sync> function, which is like C<aio_sendfile>,
		1670	but is blocking (this makes most sense if you know the input data is
		1671	likely cached already and the output filehandle is set to non-blocking
		1672	operations).
		1673
		1674	Returns the number of bytes copied, or C<-1> on error.
		1675
		1676	=item IO::AIO::fadvise $fh, $offset, $len, $advice
		1677
		1678	Simply calls the C<posix_fadvise> function (see its
		1679	manpage for details). The following advice constants are
		1680	available: C<IO::AIO::FADV_NORMAL>, C<IO::AIO::FADV_SEQUENTIAL>,
		1681	C<IO::AIO::FADV_RANDOM>, C<IO::AIO::FADV_NOREUSE>,
		1682	C<IO::AIO::FADV_WILLNEED>, C<IO::AIO::FADV_DONTNEED>.
		1683
		1684	On systems that do not implement C<posix_fadvise>, this function returns
		1685	ENOSYS, otherwise the return value of C<posix_fadvise>.
		1686
		1687	=item IO::AIO::madvise $scalar, $offset, $len, $advice
		1688
		1689	Simply calls the C<posix_madvise> function (see its
		1690	manpage for details). The following advice constants are
		1691	available: C<IO::AIO::MADV_NORMAL>, C<IO::AIO::MADV_SEQUENTIAL>,
		1692	C<IO::AIO::MADV_RANDOM>, C<IO::AIO::MADV_WILLNEED>, C<IO::AIO::MADV_DONTNEED>.
		1693
		1694	On systems that do not implement C<posix_madvise>, this function returns
		1695	ENOSYS, otherwise the return value of C<posix_madvise>.
		1696
		1697	=item IO::AIO::mprotect $scalar, $offset, $len, $protect
		1698
		1699	Simply calls the C<mprotect> function on the preferably AIO::mmap'ed
		1700	$scalar (see its manpage for details). The following protect
		1701	constants are available: C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_READ>,
		1702	C<IO::AIO::PROT_WRITE>, C<IO::AIO::PROT_EXEC>.
		1703
		1704	On systems that do not implement C<mprotect>, this function returns
		1705	ENOSYS, otherwise the return value of C<mprotect>.
		1706
		1707	=item IO::AIO::mmap $scalar, $length, $prot, $flags, $fh[, $offset]
		1708
		1709	Memory-maps a file (or anonymous memory range) and attaches it to the
		1710	given C<$scalar>, which will act like a string scalar.
		1711
		1712	The only operations allowed on the scalar are C<substr>/C<vec> that don't
		1713	change the string length, and most read-only operations such as copying it
		1714	or searching it with regexes and so on.
		1715
		1716	Anything else is unsafe and will, at best, result in memory leaks.
		1717
		1718	The memory map associated with the C<$scalar> is automatically removed
		1719	when the C<$scalar> is destroyed, or when the C<IO::AIO::mmap> or
		1720	C<IO::AIO::munmap> functions are called.
		1721
		1722	This calls the C<mmap>(2) function internally. See your system's manual
		1723	page for details on the C<$length>, C<$prot> and C<$flags> parameters.
		1724
		1725	The C<$length> must be larger than zero and smaller than the actual
		1726	filesize.
		1727
		1728	C<$prot> is a combination of C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_EXEC>,
		1729	C<IO::AIO::PROT_READ> and/or C<IO::AIO::PROT_WRITE>,
		1730
		1731	C<$flags> can be a combination of C<IO::AIO::MAP_SHARED> or
		1732	C<IO::AIO::MAP_PRIVATE>, or a number of system-specific flags (when
		1733	not available, the are defined as 0): C<IO::AIO::MAP_ANONYMOUS>
		1734	(which is set to C<MAP_ANON> if your system only provides this
		1735	constant), C<IO::AIO::MAP_HUGETLB>, C<IO::AIO::MAP_LOCKED>,
		1736	C<IO::AIO::MAP_NORESERVE>, C<IO::AIO::MAP_POPULATE> or
		1737	C<IO::AIO::MAP_NONBLOCK>
		1738
		1739	If C<$fh> is C<undef>, then a file descriptor of C<-1> is passed.
		1740
		1741	C<$offset> is the offset from the start of the file - it generally must be
		1742	a multiple of C<IO::AIO::PAGESIZE> and defaults to C<0>.
		1743
		1744	Example:
		1745
		1746	use Digest::MD5;
		1747	use IO::AIO;
		1748
		1749	open my $fh, "<verybigfile"
		1750	or die "$!";
		1751
		1752	IO::AIO::mmap my $data, -s $fh, IO::AIO::PROT_READ, IO::AIO::MAP_SHARED, $fh
		1753	or die "verybigfile: $!";
		1754
		1755	my $fast_md5 = md5 $data;
		1756
		1757	=item IO::AIO::munmap $scalar
		1758
		1759	Removes a previous mmap and undefines the C<$scalar>.
		1760
		1761	=item IO::AIO::munlock $scalar, $offset = 0, $length = undef
		1762
		1763	Calls the C<munlock> function, undoing the effects of a previous
		1764	C<aio_mlock> call (see its description for details).
		1765
		1766	=item IO::AIO::munlockall
		1767
		1768	Calls the C<munlockall> function.
		1769
		1770	On systems that do not implement C<munlockall>, this function returns
		1771	ENOSYS, otherwise the return value of C<munlockall>.
		1772
		1773	=back
		1774
1250	=cut	1775	=cut
1251		1776
1252	# support function to convert a fd into a perl filehandle
1253	sub _fd2fh {
1254	return undef if $_[0] < 0;
1255
1256	# try to generate nice filehandles
1257	my $sym = "IO::AIO::fd#$_[0]";
1258	local *$sym;
1259
1260	open *$sym, "+<&=$_[0]" # usually works under any unix
1261	or open *$sym, "<&=$_[0]" # cygwin needs this
1262	or open *$sym, ">&=$_[0]" # or this
1263	or return undef;
1264
1265	*$sym
1266	}
1267
1268	min_parallel 8;	1777	min_parallel 8;
1269		1778
1270	END { flush }	1779	END { flush }
1271		1780
1272	1;	1781	1;
1273		1782
		1783	=head1 EVENT LOOP INTEGRATION
		1784
		1785	It is recommended to use L<AnyEvent::AIO> to integrate IO::AIO
		1786	automatically into many event loops:
		1787
		1788	# AnyEvent integration (EV, Event, Glib, Tk, POE, urxvt, pureperl...)
		1789	use AnyEvent::AIO;
		1790
		1791	You can also integrate IO::AIO manually into many event loops, here are
		1792	some examples of how to do this:
		1793
		1794	# EV integration
		1795	my $aio_w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb;
		1796
		1797	# Event integration
		1798	Event->io (fd => IO::AIO::poll_fileno,
		1799	poll => 'r',
		1800	cb => \&IO::AIO::poll_cb);
		1801
		1802	# Glib/Gtk2 integration
		1803	add_watch Glib::IO IO::AIO::poll_fileno,
		1804	in => sub { IO::AIO::poll_cb; 1 };
		1805
		1806	# Tk integration
		1807	Tk::Event::IO->fileevent (IO::AIO::poll_fileno, "",
		1808	readable => \&IO::AIO::poll_cb);
		1809
		1810	# Danga::Socket integration
		1811	Danga::Socket->AddOtherFds (IO::AIO::poll_fileno =>
		1812	\&IO::AIO::poll_cb);
		1813
1274	=head2 FORK BEHAVIOUR	1814	=head2 FORK BEHAVIOUR
1275		1815
1276	This module should do "the right thing" when the process using it forks:	1816	Usage of pthreads in a program changes the semantics of fork
		1817	considerably. Specifically, only async-safe functions can be called after
		1818	fork. Perl doesn't know about this, so in general, you cannot call fork
		1819	with defined behaviour in perl if pthreads are involved. IO::AIO uses
		1820	pthreads, so this applies, but many other extensions and (for inexplicable
		1821	reasons) perl itself often is linked against pthreads, so this limitation
		1822	applies to quite a lot of perls.
1277		1823
1278	Before the fork, IO::AIO enters a quiescent state where no requests	1824	This module no longer tries to fight your OS, or POSIX. That means IO::AIO
1279	can be added in other threads and no results will be processed. After	1825	only works in the process that loaded it. Forking is fully supported, but
1280	the fork the parent simply leaves the quiescent state and continues	1826	using IO::AIO in the child is not.
1281	request/result processing, while the child frees the request/result queue
1282	(so that the requests started before the fork will only be handled in the
1283	parent). Threads will be started on demand until the limit set in the
1284	parent process has been reached again.
1285		1827
1286	In short: the parent will, after a short pause, continue as if fork had	1828	You might get around by not I<using> IO::AIO before (or after)
1287	not been called, while the child will act as if IO::AIO has not been used	1829	forking. You could also try to call the L<IO::AIO::reinit> function in the
1288	yet.	1830	child:
		1831
		1832	=over 4
		1833
		1834	=item IO::AIO::reinit
		1835
		1836	Abandons all current requests and I/O threads and simply reinitialises all
		1837	data structures. This is not an operation supported by any standards, but
		1838	happens to work on GNU/Linux and some newer BSD systems.
		1839
		1840	The only reasonable use for this function is to call it after forking, if
		1841	C<IO::AIO> was used in the parent. Calling it while IO::AIO is active in
		1842	the process will result in undefined behaviour. Calling it at any time
		1843	will also result in any undefined (by POSIX) behaviour.
		1844
		1845	=back
1289		1846
1290	=head2 MEMORY USAGE	1847	=head2 MEMORY USAGE
1291		1848
1292	Per-request usage:	1849	Per-request usage:
1293		1850
…		…
1295	bytes of memory. In addition, stat requests need a stat buffer (possibly	1852	bytes of memory. In addition, stat requests need a stat buffer (possibly
1296	a few hundred bytes), readdir requires a result buffer and so on. Perl	1853	a few hundred bytes), readdir requires a result buffer and so on. Perl
1297	scalars and other data passed into aio requests will also be locked and	1854	scalars and other data passed into aio requests will also be locked and
1298	will consume memory till the request has entered the done state.	1855	will consume memory till the request has entered the done state.
1299		1856
1300	This is now awfully much, so queuing lots of requests is not usually a	1857	This is not awfully much, so queuing lots of requests is not usually a
1301	problem.	1858	problem.
1302		1859
1303	Per-thread usage:	1860	Per-thread usage:
1304		1861
1305	In the execution phase, some aio requests require more memory for	1862	In the execution phase, some aio requests require more memory for
…		…
1310		1867
1311	Known bugs will be fixed in the next release.	1868	Known bugs will be fixed in the next release.
1312		1869
1313	=head1 SEE ALSO	1870	=head1 SEE ALSO
1314		1871
1315	L<Coro::AIO>.	1872	L<AnyEvent::AIO> for easy integration into event loops, L<Coro::AIO> for a
		1873	more natural syntax.
1316		1874
1317	=head1 AUTHOR	1875	=head1 AUTHOR
1318		1876
1319	Marc Lehmann <schmorp@schmorp.de>	1877	Marc Lehmann <schmorp@schmorp.de>
1320	http://home.schmorp.de/	1878	http://home.schmorp.de/

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