[ViewVC] Diff of: cvs/IO-AIO/AIO.pm

Comparing IO-AIO/AIO.pm (file contents):
Revision 1.109 by root, Sun Jun 3 09:44:17 2007 UTC vs.
Revision 1.181 by root, Tue May 4 21:14:01 2010 UTC

…		…
4		4
5	=head1 SYNOPSIS	5	=head1 SYNOPSIS
6		6
7	use IO::AIO;	7	use IO::AIO;
8		8
9	aio_open "/etc/passwd", O_RDONLY, 0, sub {	9	aio_open "/etc/passwd", IO::AIO::O_RDONLY, 0, sub {
10	my $fh = shift	10	my $fh = shift
11	or die "/etc/passwd: $!";	11	or die "/etc/passwd: $!";
12	...	12	...
13	};	13	};
14		14
…		…
26	$req->cancel; # cancel request if still in queue	26	$req->cancel; # cancel request if still in queue
27		27
28	my $grp = aio_group sub { print "all stats done\n" };	28	my $grp = aio_group sub { print "all stats done\n" };
29	add $grp aio_stat "..." for ...;	29	add $grp aio_stat "..." for ...;
30		30
31	# AnyEvent integration
32	open my $fh, "<&=" . IO::AIO::poll_fileno or die "$!";
33	my $w = AnyEvent->io (fh => $fh, poll => 'r', cb => sub { IO::AIO::poll_cb });
34
35	# Event integration
36	Event->io (fd => IO::AIO::poll_fileno,
37	poll => 'r',
38	cb => \&IO::AIO::poll_cb);
39
40	# Glib/Gtk2 integration
41	add_watch Glib::IO IO::AIO::poll_fileno,
42	in => sub { IO::AIO::poll_cb; 1 };
43
44	# Tk integration
45	Tk::Event::IO->fileevent (IO::AIO::poll_fileno, "",
46	readable => \&IO::AIO::poll_cb);
47
48	# Danga::Socket integration
49	Danga::Socket->AddOtherFds (IO::AIO::poll_fileno =>
50	\&IO::AIO::poll_cb);
51
52	=head1 DESCRIPTION	31	=head1 DESCRIPTION
53		32
54	This module implements asynchronous I/O using whatever means your	33	This module implements asynchronous I/O using whatever means your
55	operating system supports.	34	operating system supports. It is implemented as an interface to C<libeio>
		35	(L<http://software.schmorp.de/pkg/libeio.html>).
56		36
57	Asynchronous means that operations that can normally block your program	37	Asynchronous means that operations that can normally block your program
58	(e.g. reading from disk) will be done asynchronously: the operation	38	(e.g. reading from disk) will be done asynchronously: the operation
59	will still block, but you can do something else in the meantime. This	39	will still block, but you can do something else in the meantime. This
60	is extremely useful for programs that need to stay interactive even	40	is extremely useful for programs that need to stay interactive even
…		…
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 = '3.65';
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_sync aio_fsync
		178	aio_fdatasync aio_sync_file_range aio_pathsync aio_readahead
		179	aio_rename aio_link aio_move aio_copy aio_group
199	aio_move aio_copy aio_group aio_nop aio_mknod aio_load aio_rmtree aio_mkdir	180	aio_nop aio_mknod aio_load aio_rmtree aio_mkdir aio_chown
		181	aio_chmod aio_utime aio_truncate
200	aio_chown aio_chmod aio_utime);	182	aio_msync aio_mtouch aio_statvfs);
		183
201	our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice aio_block));	184	our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice));
202	our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush	185	our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush
203	min_parallel max_parallel max_idle	186	min_parallel max_parallel max_idle
204	nreqs nready npending nthreads	187	nreqs nready npending nthreads
205	max_poll_time max_poll_reqs);	188	max_poll_time max_poll_reqs
		189	sendfile fadvise);
		190
		191	push @AIO_REQ, qw(aio_busy); # not exported
206		192
207	@IO::AIO::GRP::ISA = 'IO::AIO::REQ';	193	@IO::AIO::GRP::ISA = 'IO::AIO::REQ';
208		194
209	require XSLoader;	195	require XSLoader;
210	XSLoader::load ("IO::AIO", $VERSION);	196	XSLoader::load ("IO::AIO", $VERSION);
211	}	197	}
212		198
213	=head1 FUNCTIONS	199	=head1 FUNCTIONS
		200
		201	=head2 QUICK OVERVIEW
		202
		203	This section simply lists the prototypes of the most important functions
		204	for quick reference. See the following sections for function-by-function
		205	documentation.
		206
		207	aio_open $pathname, $flags, $mode, $callback->($fh)
		208	aio_close $fh, $callback->($status)
		209	aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
		210	aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
		211	aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval)
		212	aio_readahead $fh,$offset,$length, $callback->($retval)
		213	aio_stat $fh_or_path, $callback->($status)
		214	aio_lstat $fh, $callback->($status)
		215	aio_statvfs $fh_or_path, $callback->($statvfs)
		216	aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
		217	aio_chown $fh_or_path, $uid, $gid, $callback->($status)
		218	aio_truncate $fh_or_path, $offset, $callback->($status)
		219	aio_chmod $fh_or_path, $mode, $callback->($status)
		220	aio_unlink $pathname, $callback->($status)
		221	aio_mknod $path, $mode, $dev, $callback->($status)
		222	aio_link $srcpath, $dstpath, $callback->($status)
		223	aio_symlink $srcpath, $dstpath, $callback->($status)
		224	aio_readlink $path, $callback->($link)
		225	aio_rename $srcpath, $dstpath, $callback->($status)
		226	aio_mkdir $pathname, $mode, $callback->($status)
		227	aio_rmdir $pathname, $callback->($status)
		228	aio_readdir $pathname, $callback->($entries)
		229	aio_readdirx $pathname, $flags, $callback->($entries, $flags)
		230	IO::AIO::READDIR_DENTS IO::AIO::READDIR_DIRS_FIRST
		231	IO::AIO::READDIR_STAT_ORDER IO::AIO::READDIR_FOUND_UNKNOWN
		232	aio_load $path, $data, $callback->($status)
		233	aio_copy $srcpath, $dstpath, $callback->($status)
		234	aio_move $srcpath, $dstpath, $callback->($status)
		235	aio_scandir $path, $maxreq, $callback->($dirs, $nondirs)
		236	aio_rmtree $path, $callback->($status)
		237	aio_sync $callback->($status)
		238	aio_fsync $fh, $callback->($status)
		239	aio_fdatasync $fh, $callback->($status)
		240	aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status)
		241	aio_pathsync $path, $callback->($status)
		242	aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
		243	aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
		244	aio_group $callback->(...)
		245	aio_nop $callback->()
		246
		247	$prev_pri = aioreq_pri [$pri]
		248	aioreq_nice $pri_adjust
		249
		250	IO::AIO::poll_wait
		251	IO::AIO::poll_cb
		252	IO::AIO::poll
		253	IO::AIO::flush
		254	IO::AIO::max_poll_reqs $nreqs
		255	IO::AIO::max_poll_time $seconds
		256	IO::AIO::min_parallel $nthreads
		257	IO::AIO::max_parallel $nthreads
		258	IO::AIO::max_idle $nthreads
		259	IO::AIO::max_outstanding $maxreqs
		260	IO::AIO::nreqs
		261	IO::AIO::nready
		262	IO::AIO::npending
		263
		264	IO::AIO::sendfile $ofh, $ifh, $offset, $count
		265	IO::AIO::fadvise $fh, $offset, $len, $advice
		266	IO::AIO::mlockall $flags
		267	IO::AIO::munlockall
214		268
215	=head2 AIO REQUEST FUNCTIONS	269	=head2 AIO REQUEST FUNCTIONS
216		270
217	All the C<aio_*> calls are more or less thin wrappers around the syscall	271	All the C<aio_*> calls are more or less thin wrappers around the syscall
218	with the same name (sans C<aio_>). The arguments are similar or identical,	272	with the same name (sans C<aio_>). The arguments are similar or identical,
219	and they all accept an additional (and optional) C<$callback> argument	273	and they all accept an additional (and optional) C<$callback> argument
220	which must be a code reference. This code reference will get called with	274	which must be a code reference. This code reference will get called with
221	the syscall return code (e.g. most syscalls return C<-1> on error, unlike	275	the syscall return code (e.g. most syscalls return C<-1> on error, unlike
222	perl, which usually delivers "false") as it's sole argument when the given	276	perl, which usually delivers "false") as its sole argument after the given
223	syscall has been executed asynchronously.	277	syscall has been executed asynchronously.
224		278
225	All functions expecting a filehandle keep a copy of the filehandle	279	All functions expecting a filehandle keep a copy of the filehandle
226	internally until the request has finished.	280	internally until the request has finished.
227		281
…		…
241	your pathnames to the locale (or other) encoding in effect in the user	295	your pathnames to the locale (or other) encoding in effect in the user
242	environment, d) use Glib::filename_from_unicode on unicode filenames or e)	296	environment, d) use Glib::filename_from_unicode on unicode filenames or e)
243	use something else to ensure your scalar has the correct contents.	297	use something else to ensure your scalar has the correct contents.
244		298
245	This works, btw. independent of the internal UTF-8 bit, which IO::AIO	299	This works, btw. independent of the internal UTF-8 bit, which IO::AIO
246	handles correctly wether it is set or not.	300	handles correctly whether it is set or not.
247		301
248	=over 4	302	=over 4
249		303
250	=item $prev_pri = aioreq_pri [$pri]	304	=item $prev_pri = aioreq_pri [$pri]
251		305
…		…
298	by the umask in effect then the request is being executed, so better never	352	by the umask in effect then the request is being executed, so better never
299	change the umask.	353	change the umask.
300		354
301	Example:	355	Example:
302		356
303	aio_open "/etc/passwd", O_RDONLY, 0, sub {	357	aio_open "/etc/passwd", IO::AIO::O_RDONLY, 0, sub {
304	if ($_[0]) {	358	if ($_[0]) {
305	print "open successful, fh is $_[0]\n";	359	print "open successful, fh is $_[0]\n";
306	...	360	...
307	} else {	361	} else {
308	die "open failed: $!\n";	362	die "open failed: $!\n";
…		…
311		365
312		366
313	=item aio_close $fh, $callback->($status)	367	=item aio_close $fh, $callback->($status)
314		368
315	Asynchronously close a file and call the callback with the result	369	Asynchronously close a file and call the callback with the result
316	code. I<WARNING:> although accepted, you should not pass in a perl	370	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		371
321	This is supposed to be a bug in the API, so that might change. It's	372	Unfortunately, you can't do this to perl. Perl I<insists> very strongly on
322	therefore best to avoid this function.	373	closing the file descriptor associated with the filehandle itself.
323		374
		375	Therefore, C<aio_close> will not close the filehandle - instead it will
		376	use dup2 to overwrite the file descriptor with the write-end of a pipe
		377	(the pipe fd will be created on demand and will be cached).
		378
		379	Or in other words: the file descriptor will be closed, but it will not be
		380	free for reuse until the perl filehandle is closed.
		381
		382	=cut
324		383
325	=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)	384	=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
326		385
327	=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)	386	=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
328		387
329	Reads or writes C<$length> bytes from the specified C<$fh> and C<$offset>	388	Reads or writes C<$length> bytes from or to the specified C<$fh> and
330	into the scalar given by C<$data> and offset C<$dataoffset> and calls the	389	C<$offset> into the scalar given by C<$data> and offset C<$dataoffset>
331	callback without the actual number of bytes read (or -1 on error, just	390	and calls the callback without the actual number of bytes read (or -1 on
332	like the syscall).	391	error, just like the syscall).
333		392
		393	C<aio_read> will, like C<sysread>, shrink or grow the C<$data> scalar to
		394	offset plus the actual number of bytes read.
		395
334	If C<$offset> is undefined, then the current file offset will be used (and	396	If C<$offset> is undefined, then the current file descriptor offset will
335	updated), otherwise the file offset will not be changed by these calls.	397	be used (and updated), otherwise the file descriptor offset will not be
		398	changed by these calls.
336		399
337	If C<$length> is undefined in C<aio_write>, use the remaining length of C<$data>.	400	If C<$length> is undefined in C<aio_write>, use the remaining length of
		401	C<$data>.
338		402
339	If C<$dataoffset> is less than zero, it will be counted from the end of	403	If C<$dataoffset> is less than zero, it will be counted from the end of
340	C<$data>.	404	C<$data>.
341		405
342	The C<$data> scalar I<MUST NOT> be modified in any way while the request	406	The C<$data> scalar I<MUST NOT> be modified in any way while the request
…		…
360	than one C<aio_sendfile> per C<$out_fh>, as they will interfere with each	424	than one C<aio_sendfile> per C<$out_fh>, as they will interfere with each
361	other.	425	other.
362		426
363	This call tries to make use of a native C<sendfile> syscall to provide	427	This call tries to make use of a native C<sendfile> syscall to provide
364	zero-copy operation. For this to work, C<$out_fh> should refer to a	428	zero-copy operation. For this to work, C<$out_fh> should refer to a
365	socket, and C<$in_fh> should refer to mmap'able file.	429	socket, and C<$in_fh> should refer to an mmap'able file.
366		430
367	If the native sendfile call fails or is not implemented, it will be	431	If a native sendfile cannot be found or it fails with C<ENOSYS>,
		432	C<ENOTSUP>, C<EOPNOTSUPP>, C<EAFNOSUPPORT>, C<EPROTOTYPE> or C<ENOTSOCK>,
368	emulated, so you can call C<aio_sendfile> on any type of filehandle	433	it will be emulated, so you can call C<aio_sendfile> on any type of
369	regardless of the limitations of the operating system.	434	filehandle regardless of the limitations of the operating system.
370		435
371	Please note, however, that C<aio_sendfile> can read more bytes from	436	Please note, however, that C<aio_sendfile> can read more bytes from
372	C<$in_fh> than are written, and there is no way to find out how many	437	C<$in_fh> than are written, and there is no way to find out how many
373	bytes have been read from C<aio_sendfile> alone, as C<aio_sendfile> only	438	bytes have been read from C<aio_sendfile> alone, as C<aio_sendfile> only
374	provides the number of bytes written to C<$out_fh>. Only if the result	439	provides the number of bytes written to C<$out_fh>. Only if the result
…		…
412	$_[0] and die "stat failed: $!";	477	$_[0] and die "stat failed: $!";
413	print "size is ", -s _, "\n";	478	print "size is ", -s _, "\n";
414	};	479	};
415		480
416		481
		482	=item aio_statvfs $fh_or_path, $callback->($statvfs)
		483
		484	Works like the POSIX C<statvfs> or C<fstatvfs> syscalls, depending on
		485	whether a file handle or path was passed.
		486
		487	On success, the callback is passed a hash reference with the following
		488	members: C<bsize>, C<frsize>, C<blocks>, C<bfree>, C<bavail>, C<files>,
		489	C<ffree>, C<favail>, C<fsid>, C<flag> and C<namemax>. On failure, C<undef>
		490	is passed.
		491
		492	The following POSIX IO::AIO::ST_* constants are defined: C<ST_RDONLY> and
		493	C<ST_NOSUID>.
		494
		495	The following non-POSIX IO::AIO::ST_* flag masks are defined to
		496	their correct value when available, or to C<0> on systems that do
		497	not support them: C<ST_NODEV>, C<ST_NOEXEC>, C<ST_SYNCHRONOUS>,
		498	C<ST_MANDLOCK>, C<ST_WRITE>, C<ST_APPEND>, C<ST_IMMUTABLE>, C<ST_NOATIME>,
		499	C<ST_NODIRATIME> and C<ST_RELATIME>.
		500
		501	Example: stat C</wd> and dump out the data if successful.
		502
		503	aio_statvfs "/wd", sub {
		504	my $f = $_[0]
		505	or die "statvfs: $!";
		506
		507	use Data::Dumper;
		508	say Dumper $f;
		509	};
		510
		511	# result:
		512	{
		513	bsize => 1024,
		514	bfree => 4333064312,
		515	blocks => 10253828096,
		516	files => 2050765568,
		517	flag => 4096,
		518	favail => 2042092649,
		519	bavail => 4333064312,
		520	ffree => 2042092649,
		521	namemax => 255,
		522	frsize => 1024,
		523	fsid => 1810
		524	}
		525
		526
417	=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status)	527	=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
418		528
419	Works like perl's C<utime> function (including the special case of $atime	529	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	530	and $mtime being undef). Fractional times are supported if the underlying
421	syscalls support them.	531	syscalls support them.
…		…
443	aio_chown "path", 0, -1;	553	aio_chown "path", 0, -1;
444	# same as above:	554	# same as above:
445	aio_chown "path", 0, undef;	555	aio_chown "path", 0, undef;
446		556
447		557
		558	=item aio_truncate $fh_or_path, $offset, $callback->($status)
		559
		560	Works like truncate(2) or ftruncate(2).
		561
		562
448	=item aio_chmod $fh_or_path, $mode, $callback->($status)	563	=item aio_chmod $fh_or_path, $mode, $callback->($status)
449		564
450	Works like perl's C<chmod> function.	565	Works like perl's C<chmod> function.
451		566
452		567
…		…
509		624
510	Unlike the POSIX call of the same name, C<aio_readdir> reads an entire	625	Unlike the POSIX call of the same name, C<aio_readdir> reads an entire
511	directory (i.e. opendir + readdir + closedir). The entries will not be	626	directory (i.e. opendir + readdir + closedir). The entries will not be
512	sorted, and will B<NOT> include the C<.> and C<..> entries.	627	sorted, and will B<NOT> include the C<.> and C<..> entries.
513		628
514	The callback a single argument which is either C<undef> or an array-ref	629	The callback is passed a single argument which is either C<undef> or an
515	with the filenames.	630	array-ref with the filenames.
		631
		632
		633	=item aio_readdirx $pathname, $flags, $callback->($entries, $flags)
		634
		635	Quite similar to C<aio_readdir>, but the C<$flags> argument allows to tune
		636	behaviour and output format. In case of an error, C<$entries> will be
		637	C<undef>.
		638
		639	The flags are a combination of the following constants, ORed together (the
		640	flags will also be passed to the callback, possibly modified):
		641
		642	=over 4
		643
		644	=item IO::AIO::READDIR_DENTS
		645
		646	When this flag is off, then the callback gets an arrayref with of names
		647	only (as with C<aio_readdir>), otherwise it gets an arrayref with
		648	C<[$name, $type, $inode]> arrayrefs, each describing a single directory
		649	entry in more detail.
		650
		651	C<$name> is the name of the entry.
		652
		653	C<$type> is one of the C<IO::AIO::DT_xxx> constants:
		654
		655	C<IO::AIO::DT_UNKNOWN>, C<IO::AIO::DT_FIFO>, C<IO::AIO::DT_CHR>, C<IO::AIO::DT_DIR>,
		656	C<IO::AIO::DT_BLK>, C<IO::AIO::DT_REG>, C<IO::AIO::DT_LNK>, C<IO::AIO::DT_SOCK>,
		657	C<IO::AIO::DT_WHT>.
		658
		659	C<IO::AIO::DT_UNKNOWN> means just that: readdir does not know. If you need to
		660	know, you have to run stat yourself. Also, for speed reasons, the C<$type>
		661	scalars are read-only: you can not modify them.
		662
		663	C<$inode> is the inode number (which might not be exact on systems with 64
		664	bit inode numbers and 32 bit perls). This field has unspecified content on
		665	systems that do not deliver the inode information.
		666
		667	=item IO::AIO::READDIR_DIRS_FIRST
		668
		669	When this flag is set, then the names will be returned in an order where
		670	likely directories come first. This is useful when you need to quickly
		671	find directories, or you want to find all directories while avoiding to
		672	stat() each entry.
		673
		674	If the system returns type information in readdir, then this is used
		675	to find directories directly. Otherwise, likely directories are files
		676	beginning with ".", or otherwise files with no dots, of which files with
		677	short names are tried first.
		678
		679	=item IO::AIO::READDIR_STAT_ORDER
		680
		681	When this flag is set, then the names will be returned in an order
		682	suitable for stat()'ing each one. That is, when you plan to stat()
		683	all files in the given directory, then the returned order will likely
		684	be fastest.
		685
		686	If both this flag and C<IO::AIO::READDIR_DIRS_FIRST> are specified, then
		687	the likely dirs come first, resulting in a less optimal stat order.
		688
		689	=item IO::AIO::READDIR_FOUND_UNKNOWN
		690
		691	This flag should not be set when calling C<aio_readdirx>. Instead, it
		692	is being set by C<aio_readdirx>, when any of the C<$type>'s found were
		693	C<IO::AIO::DT_UNKNOWN>. The absense of this flag therefore indicates that all
		694	C<$type>'s are known, which can be used to speed up some algorithms.
		695
		696	=back
516		697
517		698
518	=item aio_load $path, $data, $callback->($status)	699	=item aio_load $path, $data, $callback->($status)
519		700
520	This is a composite request that tries to fully load the given file into	701	This is a composite request that tries to fully load the given file into
521	memory. Status is the same as with aio_read.	702	memory. Status is the same as with aio_read.
522		703
523	=cut	704	=cut
524		705
525	sub aio_load($$;$) {	706	sub aio_load($$;$) {
526	aio_block {
527	my ($path, undef, $cb) = @_;	707	my ($path, undef, $cb) = @_;
528	my $data = \$_[1];	708	my $data = \$_[1];
529		709
530	my $pri = aioreq_pri;	710	my $pri = aioreq_pri;
531	my $grp = aio_group $cb;	711	my $grp = aio_group $cb;
		712
		713	aioreq_pri $pri;
		714	add $grp aio_open $path, O_RDONLY, 0, sub {
		715	my $fh = shift
		716	or return $grp->result (-1);
532		717
533	aioreq_pri $pri;	718	aioreq_pri $pri;
534	add $grp aio_open $path, O_RDONLY, 0, sub {
535	my $fh = shift
536	or return $grp->result (-1);
537
538	aioreq_pri $pri;
539	add $grp aio_read $fh, 0, (-s $fh), $$data, 0, sub {	719	add $grp aio_read $fh, 0, (-s $fh), $$data, 0, sub {
540	$grp->result ($_[0]);	720	$grp->result ($_[0]);
541	};
542	};	721	};
543
544	$grp
545	}	722	};
		723
		724	$grp
546	}	725	}
547		726
548	=item aio_copy $srcpath, $dstpath, $callback->($status)	727	=item aio_copy $srcpath, $dstpath, $callback->($status)
549		728
550	Try to copy the I<file> (directories not supported as either source or	729	Try to copy the I<file> (directories not supported as either source or
551	destination) from C<$srcpath> to C<$dstpath> and call the callback with	730	destination) from C<$srcpath> to C<$dstpath> and call the callback with
552	the C<0> (error) or C<-1> ok.	731	a status of C<0> (ok) or C<-1> (error, see C<$!>).
553		732
554	This is a composite request that it creates the destination file with	733	This is a composite request that creates the destination file with
555	mode 0200 and copies the contents of the source file into it using	734	mode 0200 and copies the contents of the source file into it using
556	C<aio_sendfile>, followed by restoring atime, mtime, access mode and	735	C<aio_sendfile>, followed by restoring atime, mtime, access mode and
557	uid/gid, in that order.	736	uid/gid, in that order.
558		737
559	If an error occurs, the partial destination file will be unlinked, if	738	If an error occurs, the partial destination file will be unlinked, if
…		…
561	errors are being ignored.	740	errors are being ignored.
562		741
563	=cut	742	=cut
564		743
565	sub aio_copy($$;$) {	744	sub aio_copy($$;$) {
566	aio_block {
567	my ($src, $dst, $cb) = @_;	745	my ($src, $dst, $cb) = @_;
568		746
569	my $pri = aioreq_pri;	747	my $pri = aioreq_pri;
570	my $grp = aio_group $cb;	748	my $grp = aio_group $cb;
571		749
572	aioreq_pri $pri;	750	aioreq_pri $pri;
573	add $grp aio_open $src, O_RDONLY, 0, sub {	751	add $grp aio_open $src, O_RDONLY, 0, sub {
574	if (my $src_fh = $_[0]) {	752	if (my $src_fh = $_[0]) {
575	my @stat = stat $src_fh;	753	my @stat = stat $src_fh; # hmm, might block over nfs?
576		754
577	aioreq_pri $pri;	755	aioreq_pri $pri;
578	add $grp aio_open $dst, O_CREAT \| O_WRONLY \| O_TRUNC, 0200, sub {	756	add $grp aio_open $dst, O_CREAT \| O_WRONLY \| O_TRUNC, 0200, sub {
579	if (my $dst_fh = $_[0]) {	757	if (my $dst_fh = $_[0]) {
580	aioreq_pri $pri;	758	aioreq_pri $pri;
581	add $grp aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub {	759	add $grp aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub {
582	if ($_[0] == $stat[7]) {	760	if ($_[0] == $stat[7]) {
583	$grp->result (0);	761	$grp->result (0);
584	close $src_fh;	762	close $src_fh;
585		763
586	# those should not normally block. should. should.
587	utime $stat[8], $stat[9], $dst;
588	chmod $stat[2] & 07777, $dst_fh;
589	chown $stat[4], $stat[5], $dst_fh;
590	close $dst_fh;
591	} else {	764	my $ch = sub {
592	$grp->result (-1);
593	close $src_fh;
594	close $dst_fh;
595
596	aioreq $pri;	765	aioreq_pri $pri;
		766	add $grp aio_chmod $dst_fh, $stat[2] & 07777, sub {
		767	aioreq_pri $pri;
		768	add $grp aio_chown $dst_fh, $stat[4], $stat[5], sub {
		769	aioreq_pri $pri;
597	add $grp aio_unlink $dst;	770	add $grp aio_close $dst_fh;
		771	}
		772	};
598	}	773	};
		774
		775	aioreq_pri $pri;
		776	add $grp aio_utime $dst_fh, $stat[8], $stat[9], sub {
		777	if ($_[0] < 0 && $! == ENOSYS) {
		778	aioreq_pri $pri;
		779	add $grp aio_utime $dst, $stat[8], $stat[9], $ch;
		780	} else {
		781	$ch->();
		782	}
		783	};
		784	} else {
		785	$grp->result (-1);
		786	close $src_fh;
		787	close $dst_fh;
		788
		789	aioreq $pri;
		790	add $grp aio_unlink $dst;
599	};	791	}
600	} else {
601	$grp->result (-1);
602	}	792	};
		793	} else {
		794	$grp->result (-1);
603	},	795	}
604
605	} else {
606	$grp->result (-1);
607	}	796	},
		797
		798	} else {
		799	$grp->result (-1);
608	};	800	}
609
610	$grp
611	}	801	};
		802
		803	$grp
612	}	804	}
613		805
614	=item aio_move $srcpath, $dstpath, $callback->($status)	806	=item aio_move $srcpath, $dstpath, $callback->($status)
615		807
616	Try to move the I<file> (directories not supported as either source or	808	Try to move the I<file> (directories not supported as either source or
617	destination) from C<$srcpath> to C<$dstpath> and call the callback with	809	destination) from C<$srcpath> to C<$dstpath> and call the callback with
618	the C<0> (error) or C<-1> ok.	810	a status of C<0> (ok) or C<-1> (error, see C<$!>).
619		811
620	This is a composite request that tries to rename(2) the file first. If	812	This is a composite request that tries to rename(2) the file first; if
621	rename files with C<EXDEV>, it copies the file with C<aio_copy> and, if	813	rename fails with C<EXDEV>, it copies the file with C<aio_copy> and, if
622	that is successful, unlinking the C<$srcpath>.	814	that is successful, unlinks the C<$srcpath>.
623		815
624	=cut	816	=cut
625		817
626	sub aio_move($$;$) {	818	sub aio_move($$;$) {
627	aio_block {
628	my ($src, $dst, $cb) = @_;	819	my ($src, $dst, $cb) = @_;
629		820
630	my $pri = aioreq_pri;	821	my $pri = aioreq_pri;
631	my $grp = aio_group $cb;	822	my $grp = aio_group $cb;
632		823
633	aioreq_pri $pri;	824	aioreq_pri $pri;
634	add $grp aio_rename $src, $dst, sub {	825	add $grp aio_rename $src, $dst, sub {
635	if ($_[0] && $! == EXDEV) {	826	if ($_[0] && $! == EXDEV) {
636	aioreq_pri $pri;	827	aioreq_pri $pri;
637	add $grp aio_copy $src, $dst, sub {	828	add $grp aio_copy $src, $dst, sub {
638	$grp->result ($_[0]);
639
640	if (!$_[0]) {
641	aioreq_pri $pri;
642	add $grp aio_unlink $src;
643	}
644	};
645	} else {
646	$grp->result ($_[0]);	829	$grp->result ($_[0]);
		830
		831	if (!$_[0]) {
		832	aioreq_pri $pri;
		833	add $grp aio_unlink $src;
		834	}
647	}	835	};
		836	} else {
		837	$grp->result ($_[0]);
648	};	838	}
649
650	$grp
651	}	839	};
		840
		841	$grp
652	}	842	}
653		843
654	=item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs)	844	=item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs)
655		845
656	Scans a directory (similar to C<aio_readdir>) but additionally tries to	846	Scans a directory (similar to C<aio_readdir>) but additionally tries to
…		…
676		866
677	Implementation notes.	867	Implementation notes.
678		868
679	The C<aio_readdir> cannot be avoided, but C<stat()>'ing every entry can.	869	The C<aio_readdir> cannot be avoided, but C<stat()>'ing every entry can.
680		870
		871	If readdir returns file type information, then this is used directly to
		872	find directories.
		873
681	After reading the directory, the modification time, size etc. of the	874	Otherwise, after reading the directory, the modification time, size etc.
682	directory before and after the readdir is checked, and if they match (and	875	of the directory before and after the readdir is checked, and if they
683	isn't the current time), the link count will be used to decide how many	876	match (and isn't the current time), the link count will be used to decide
684	entries are directories (if >= 2). Otherwise, no knowledge of the number	877	how many entries are directories (if >= 2). Otherwise, no knowledge of the
685	of subdirectories will be assumed.	878	number of subdirectories will be assumed.
686		879
687	Then entries will be sorted into likely directories (everything without	880	Then entries will be sorted into likely directories a non-initial dot
688	a non-initial dot currently) and likely non-directories (everything	881	currently) and likely non-directories (see C<aio_readdirx>). Then every
689	else). Then every entry plus an appended C</.> will be C<stat>'ed,	882	entry plus an appended C</.> will be C<stat>'ed, likely directories first,
690	likely directories first. If that succeeds, it assumes that the entry	883	in order of their inode numbers. If that succeeds, it assumes that the
691	is a directory or a symlink to directory (which will be checked	884	entry is a directory or a symlink to directory (which will be checked
692	seperately). This is often faster than stat'ing the entry itself because	885	seperately). This is often faster than stat'ing the entry itself because
693	filesystems might detect the type of the entry without reading the inode	886	filesystems might detect the type of the entry without reading the inode
694	data (e.g. ext2fs filetype feature).	887	data (e.g. ext2fs filetype feature), even on systems that cannot return
		888	the filetype information on readdir.
695		889
696	If the known number of directories (link count - 2) has been reached, the	890	If the known number of directories (link count - 2) has been reached, the
697	rest of the entries is assumed to be non-directories.	891	rest of the entries is assumed to be non-directories.
698		892
699	This only works with certainty on POSIX (= UNIX) filesystems, which	893	This only works with certainty on POSIX (= UNIX) filesystems, which
…		…
704	directory counting heuristic.	898	directory counting heuristic.
705		899
706	=cut	900	=cut
707		901
708	sub aio_scandir($$;$) {	902	sub aio_scandir($$;$) {
709	aio_block {
710	my ($path, $maxreq, $cb) = @_;	903	my ($path, $maxreq, $cb) = @_;
711		904
712	my $pri = aioreq_pri;	905	my $pri = aioreq_pri;
713		906
714	my $grp = aio_group $cb;	907	my $grp = aio_group $cb;
715		908
716	$maxreq = 4 if $maxreq <= 0;	909	$maxreq = 4 if $maxreq <= 0;
717		910
718	# stat once	911	# stat once
		912	aioreq_pri $pri;
		913	add $grp aio_stat $path, sub {
		914	return $grp->result () if $_[0];
		915	my $now = time;
		916	my $hash1 = join ":", (stat _)[0,1,3,7,9];
		917
		918	# read the directory entries
719	aioreq_pri $pri;	919	aioreq_pri $pri;
720	add $grp aio_stat $path, sub {	920	add $grp aio_readdirx $path, READDIR_DIRS_FIRST, sub {
		921	my $entries = shift
721	return $grp->result () if $_[0];	922	or return $grp->result ();
722	my $now = time;
723	my $hash1 = join ":", (stat _)[0,1,3,7,9];
724		923
725	# read the directory entries	924	# stat the dir another time
726	aioreq_pri $pri;	925	aioreq_pri $pri;
727	add $grp aio_readdir $path, sub {
728	my $entries = shift
729	or return $grp->result ();
730
731	# stat the dir another time
732	aioreq_pri $pri;
733	add $grp aio_stat $path, sub {	926	add $grp aio_stat $path, sub {
734	my $hash2 = join ":", (stat _)[0,1,3,7,9];	927	my $hash2 = join ":", (stat _)[0,1,3,7,9];
735		928
736	my $ndirs;	929	my $ndirs;
737		930
738	# take the slow route if anything looks fishy	931	# take the slow route if anything looks fishy
739	if ($hash1 ne $hash2 or (stat _)[9] == $now) {	932	if ($hash1 ne $hash2 or (stat _)[9] == $now) {
740	$ndirs = -1;	933	$ndirs = -1;
741	} else {	934	} else {
742	# if nlink == 2, we are finished	935	# if nlink == 2, we are finished
743	# on non-posix-fs's, we rely on nlink < 2	936	# for non-posix-fs's, we rely on nlink < 2
744	$ndirs = (stat _)[3] - 2	937	$ndirs = (stat _)[3] - 2
745	or return $grp->result ([], $entries);	938	or return $grp->result ([], $entries);
746	}	939	}
747		940
748	# sort into likely dirs and likely nondirs
749	# dirs == files without ".", short entries first
750	$entries = [map $_->[0],
751	sort { $b->[1] cmp $a->[1] }
752	map [$_, sprintf "%s%04d", (/.\./ ? "1" : "0"), length],
753	@$entries];
754
755	my (@dirs, @nondirs);	941	my (@dirs, @nondirs);
756		942
757	my $statgrp = add $grp aio_group sub {	943	my $statgrp = add $grp aio_group sub {
758	$grp->result (\@dirs, \@nondirs);	944	$grp->result (\@dirs, \@nondirs);
759	};	945	};
760		946
761	limit $statgrp $maxreq;	947	limit $statgrp $maxreq;
762	feed $statgrp sub {	948	feed $statgrp sub {
763	return unless @$entries;	949	return unless @$entries;
764	my $entry = pop @$entries;	950	my $entry = shift @$entries;
765		951
766	aioreq_pri $pri;	952	aioreq_pri $pri;
767	add $statgrp aio_stat "$path/$entry/.", sub {	953	add $statgrp aio_stat "$path/$entry/.", sub {
768	if ($_[0] < 0) {	954	if ($_[0] < 0) {
769	push @nondirs, $entry;	955	push @nondirs, $entry;
770	} else {	956	} else {
771	# need to check for real directory	957	# need to check for real directory
772	aioreq_pri $pri;	958	aioreq_pri $pri;
773	add $statgrp aio_lstat "$path/$entry", sub {	959	add $statgrp aio_lstat "$path/$entry", sub {
774	if (-d _) {	960	if (-d _) {
775	push @dirs, $entry;	961	push @dirs, $entry;
776		962
777	unless (--$ndirs) {	963	unless (--$ndirs) {
778	push @nondirs, @$entries;	964	push @nondirs, @$entries;
779	feed $statgrp;	965	feed $statgrp;
780	}
781	} else {
782	push @nondirs, $entry;
783	}	966	}
		967	} else {
		968	push @nondirs, $entry;
784	}	969	}
785	}	970	}
786	};	971	}
787	};	972	};
788	};	973	};
789	};	974	};
790	};	975	};
791
792	$grp
793	}	976	};
		977
		978	$grp
794	}	979	}
795		980
796	=item aio_rmtree $path, $callback->($status)	981	=item aio_rmtree $path, $callback->($status)
797		982
798	Delete a directory tree starting (and including) C<$path>, return the	983	Delete a directory tree starting (and including) C<$path>, return the
…		…
802		987
803	=cut	988	=cut
804		989
805	sub aio_rmtree;	990	sub aio_rmtree;
806	sub aio_rmtree($;$) {	991	sub aio_rmtree($;$) {
807	aio_block {
808	my ($path, $cb) = @_;	992	my ($path, $cb) = @_;
809		993
810	my $pri = aioreq_pri;	994	my $pri = aioreq_pri;
811	my $grp = aio_group $cb;	995	my $grp = aio_group $cb;
812		996
813	aioreq_pri $pri;	997	aioreq_pri $pri;
814	add $grp aio_scandir $path, 0, sub {	998	add $grp aio_scandir $path, 0, sub {
815	my ($dirs, $nondirs) = @_;	999	my ($dirs, $nondirs) = @_;
816		1000
817	my $dirgrp = aio_group sub {	1001	my $dirgrp = aio_group sub {
818	add $grp aio_rmdir $path, sub {	1002	add $grp aio_rmdir $path, sub {
819	$grp->result ($_[0]);	1003	$grp->result ($_[0]);
820	};
821	};	1004	};
822
823	(aioreq_pri $pri), add $dirgrp aio_rmtree "$path/$_" for @$dirs;
824	(aioreq_pri $pri), add $dirgrp aio_unlink "$path/$_" for @$nondirs;
825
826	add $grp $dirgrp;
827	};	1005	};
828		1006
829	$grp	1007	(aioreq_pri $pri), add $dirgrp aio_rmtree "$path/$_" for @$dirs;
		1008	(aioreq_pri $pri), add $dirgrp aio_unlink "$path/$_" for @$nondirs;
		1009
		1010	add $grp $dirgrp;
830	}	1011	};
		1012
		1013	$grp
831	}	1014	}
		1015
		1016	=item aio_sync $callback->($status)
		1017
		1018	Asynchronously call sync and call the callback when finished.
832		1019
833	=item aio_fsync $fh, $callback->($status)	1020	=item aio_fsync $fh, $callback->($status)
834		1021
835	Asynchronously call fsync on the given filehandle and call the callback	1022	Asynchronously call fsync on the given filehandle and call the callback
836	with the fsync result code.	1023	with the fsync result code.
…		…
840	Asynchronously call fdatasync on the given filehandle and call the	1027	Asynchronously call fdatasync on the given filehandle and call the
841	callback with the fdatasync result code.	1028	callback with the fdatasync result code.
842		1029
843	If this call isn't available because your OS lacks it or it couldn't be	1030	If this call isn't available because your OS lacks it or it couldn't be
844	detected, it will be emulated by calling C<fsync> instead.	1031	detected, it will be emulated by calling C<fsync> instead.
		1032
		1033	=item aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status)
		1034
		1035	Sync the data portion of the file specified by C<$offset> and C<$length>
		1036	to disk (but NOT the metadata), by calling the Linux-specific
		1037	sync_file_range call. If sync_file_range is not available or it returns
		1038	ENOSYS, then fdatasync or fsync is being substituted.
		1039
		1040	C<$flags> can be a combination of C<IO::AIO::SYNC_FILE_RANGE_WAIT_BEFORE>,
		1041	C<IO::AIO::SYNC_FILE_RANGE_WRITE> and
		1042	C<IO::AIO::SYNC_FILE_RANGE_WAIT_AFTER>: refer to the sync_file_range
		1043	manpage for details.
		1044
		1045	=item aio_pathsync $path, $callback->($status)
		1046
		1047	This request tries to open, fsync and close the given path. This is a
		1048	composite request intended to sync directories after directory operations
		1049	(E.g. rename). This might not work on all operating systems or have any
		1050	specific effect, but usually it makes sure that directory changes get
		1051	written to disc. It works for anything that can be opened for read-only,
		1052	not just directories.
		1053
		1054	Future versions of this function might fall back to other methods when
		1055	C<fsync> on the directory fails (such as calling C<sync>).
		1056
		1057	Passes C<0> when everything went ok, and C<-1> on error.
		1058
		1059	=cut
		1060
		1061	sub aio_pathsync($;$) {
		1062	my ($path, $cb) = @_;
		1063
		1064	my $pri = aioreq_pri;
		1065	my $grp = aio_group $cb;
		1066
		1067	aioreq_pri $pri;
		1068	add $grp aio_open $path, O_RDONLY, 0, sub {
		1069	my ($fh) = @_;
		1070	if ($fh) {
		1071	aioreq_pri $pri;
		1072	add $grp aio_fsync $fh, sub {
		1073	$grp->result ($_[0]);
		1074
		1075	aioreq_pri $pri;
		1076	add $grp aio_close $fh;
		1077	};
		1078	} else {
		1079	$grp->result (-1);
		1080	}
		1081	};
		1082
		1083	$grp
		1084	}
		1085
		1086	=item aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
		1087
		1088	This is a rather advanced IO::AIO call, which only works on mmap(2)ed
		1089	scalars (see the C<IO::AIO::mmap> function, although it also works on data
		1090	scalars managed by the L<Sys::Mmap> or L<Mmap> modules, note that the
		1091	scalar must only be modified in-place while an aio operation is pending on
		1092	it).
		1093
		1094	It calls the C<msync> function of your OS, if available, with the memory
		1095	area starting at C<$offset> in the string and ending C<$length> bytes
		1096	later. If C<$length> is negative, counts from the end, and if C<$length>
		1097	is C<undef>, then it goes till the end of the string. The flags can be
		1098	a combination of C<IO::AIO::MS_ASYNC>, C<IO::AIO::MS_INVALIDATE> and
		1099	C<IO::AIO::MS_SYNC>.
		1100
		1101	=item aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
		1102
		1103	This is a rather advanced IO::AIO call, which works best on mmap(2)ed
		1104	scalars.
		1105
		1106	It touches (reads or writes) all memory pages in the specified
		1107	range inside the scalar. All caveats and parameters are the same
		1108	as for C<aio_msync>, above, except for flags, which must be either
		1109	C<0> (which reads all pages and ensures they are instantiated) or
		1110	C<IO::AIO::MT_MODIFY>, which modifies the memory page s(by reading and
		1111	writing an octet from it, which dirties the page).
845		1112
846	=item aio_group $callback->(...)	1113	=item aio_group $callback->(...)
847		1114
848	This is a very special aio request: Instead of doing something, it is a	1115	This is a very special aio request: Instead of doing something, it is a
849	container for other aio requests, which is useful if you want to bundle	1116	container for other aio requests, which is useful if you want to bundle
…		…
899	=item cancel $req	1166	=item cancel $req
900		1167
901	Cancels the request, if possible. Has the effect of skipping execution	1168	Cancels the request, if possible. Has the effect of skipping execution
902	when entering the B<execute> state and skipping calling the callback when	1169	when entering the B<execute> state and skipping calling the callback when
903	entering the the B<result> state, but will leave the request otherwise	1170	entering the the B<result> state, but will leave the request otherwise
904	untouched. That means that requests that currently execute will not be	1171	untouched (with the exception of readdir). That means that requests that
905	stopped and resources held by the request will not be freed prematurely.	1172	currently execute will not be stopped and resources held by the request
		1173	will not be freed prematurely.
906		1174
907	=item cb $req $callback->(...)	1175	=item cb $req $callback->(...)
908		1176
909	Replace (or simply set) the callback registered to the request.	1177	Replace (or simply set) the callback registered to the request.
910		1178
…		…
961	Their lifetime, simplified, looks like this: when they are empty, they	1229	Their lifetime, simplified, looks like this: when they are empty, they
962	will finish very quickly. If they contain only requests that are in the	1230	will finish very quickly. If they contain only requests that are in the
963	C<done> state, they will also finish. Otherwise they will continue to	1231	C<done> state, they will also finish. Otherwise they will continue to
964	exist.	1232	exist.
965		1233
966	That means after creating a group you have some time to add requests. And	1234	That means after creating a group you have some time to add requests
967	in the callbacks of those requests, you can add further requests to the	1235	(precisely before the callback has been invoked, which is only done within
968	group. And only when all those requests have finished will the the group	1236	the C<poll_cb>). And in the callbacks of those requests, you can add
969	itself finish.	1237	further requests to the group. And only when all those requests have
		1238	finished will the the group itself finish.
970		1239
971	=over 4	1240	=over 4
972		1241
973	=item add $grp ...	1242	=item add $grp ...
974		1243
…		…
983	=item $grp->cancel_subs	1252	=item $grp->cancel_subs
984		1253
985	Cancel all subrequests and clears any feeder, but not the group request	1254	Cancel all subrequests and clears any feeder, but not the group request
986	itself. Useful when you queued a lot of events but got a result early.	1255	itself. Useful when you queued a lot of events but got a result early.
987		1256
		1257	The group request will finish normally (you cannot add requests to the
		1258	group).
		1259
988	=item $grp->result (...)	1260	=item $grp->result (...)
989		1261
990	Set the result value(s) that will be passed to the group callback when all	1262	Set the result value(s) that will be passed to the group callback when all
991	subrequests have finished and set thre groups errno to the current value	1263	subrequests have finished and set the groups errno to the current value
992	of errno (just like calling C<errno> without an error number). By default,	1264	of errno (just like calling C<errno> without an error number). By default,
993	no argument will be passed and errno is zero.	1265	no argument will be passed and errno is zero.
994		1266
995	=item $grp->errno ([$errno])	1267	=item $grp->errno ([$errno])
996		1268
…		…
1007	=item feed $grp $callback->($grp)	1279	=item feed $grp $callback->($grp)
1008		1280
1009	Sets a feeder/generator on this group: every group can have an attached	1281	Sets a feeder/generator on this group: every group can have an attached
1010	generator that generates requests if idle. The idea behind this is that,	1282	generator that generates requests if idle. The idea behind this is that,
1011	although you could just queue as many requests as you want in a group,	1283	although you could just queue as many requests as you want in a group,
1012	this might starve other requests for a potentially long time. For	1284	this might starve other requests for a potentially long time. For example,
1013	example, C<aio_scandir> might generate hundreds of thousands C<aio_stat>	1285	C<aio_scandir> might generate hundreds of thousands C<aio_stat> requests,
1014	requests, delaying any later requests for a long time.	1286	delaying any later requests for a long time.
1015		1287
1016	To avoid this, and allow incremental generation of requests, you can	1288	To avoid this, and allow incremental generation of requests, you can
1017	instead a group and set a feeder on it that generates those requests. The	1289	instead a group and set a feeder on it that generates those requests. The
1018	feed callback will be called whenever there are few enough (see C<limit>,	1290	feed callback will be called whenever there are few enough (see C<limit>,
1019	below) requests active in the group itself and is expected to queue more	1291	below) requests active in the group itself and is expected to queue more
…		…
1023	not impose any limits).	1295	not impose any limits).
1024		1296
1025	If the feed does not queue more requests when called, it will be	1297	If the feed does not queue more requests when called, it will be
1026	automatically removed from the group.	1298	automatically removed from the group.
1027		1299
1028	If the feed limit is C<0>, it will be set to C<2> automatically.	1300	If the feed limit is C<0> when this method is called, it will be set to
		1301	C<2> automatically.
1029		1302
1030	Example:	1303	Example:
1031		1304
1032	# stat all files in @files, but only ever use four aio requests concurrently:	1305	# stat all files in @files, but only ever use four aio requests concurrently:
1033		1306
…		…
1045	Sets the feeder limit for the group: The feeder will be called whenever	1318	Sets the feeder limit for the group: The feeder will be called whenever
1046	the group contains less than this many requests.	1319	the group contains less than this many requests.
1047		1320
1048	Setting the limit to C<0> will pause the feeding process.	1321	Setting the limit to C<0> will pause the feeding process.
1049		1322
		1323	The default value for the limit is C<0>, but note that setting a feeder
		1324	automatically bumps it up to C<2>.
		1325
1050	=back	1326	=back
1051		1327
1052	=head2 SUPPORT FUNCTIONS	1328	=head2 SUPPORT FUNCTIONS
1053		1329
1054	=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION	1330	=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION
…		…
1056	=over 4	1332	=over 4
1057		1333
1058	=item $fileno = IO::AIO::poll_fileno	1334	=item $fileno = IO::AIO::poll_fileno
1059		1335
1060	Return the I<request result pipe file descriptor>. This filehandle must be	1336	Return the I<request result pipe file descriptor>. This filehandle must be
1061	polled for reading by some mechanism outside this module (e.g. Event or	1337	polled for reading by some mechanism outside this module (e.g. EV, Glib,
1062	select, see below or the SYNOPSIS). If the pipe becomes readable you have	1338	select and so on, see below or the SYNOPSIS). If the pipe becomes readable
1063	to call C<poll_cb> to check the results.	1339	you have to call C<poll_cb> to check the results.
1064		1340
1065	See C<poll_cb> for an example.	1341	See C<poll_cb> for an example.
1066		1342
1067	=item IO::AIO::poll_cb	1343	=item IO::AIO::poll_cb
1068		1344
1069	Process some outstanding events on the result pipe. You have to call this	1345	Process some outstanding events on the result pipe. You have to call this
1070	regularly. Returns the number of events processed. Returns immediately	1346	regularly. Returns C<0> if all events could be processed, or C<-1> if it
		1347	returned earlier for whatever reason. Returns immediately when no events
1071	when no events are outstanding. The amount of events processed depends on	1348	are outstanding. The amount of events processed depends on the settings of
1072	the settings of C<IO::AIO::max_poll_req> and C<IO::AIO::max_poll_time>.	1349	C<IO::AIO::max_poll_req> and C<IO::AIO::max_poll_time>.
1073		1350
1074	If not all requests were processed for whatever reason, the filehandle	1351	If not all requests were processed for whatever reason, the filehandle
1075	will still be ready when C<poll_cb> returns.	1352	will still be ready when C<poll_cb> returns, so normally you don't have to
		1353	do anything special to have it called later.
1076		1354
1077	Example: Install an Event watcher that automatically calls	1355	Example: Install an Event watcher that automatically calls
1078	IO::AIO::poll_cb with high priority:	1356	IO::AIO::poll_cb with high priority (more examples can be found in the
		1357	SYNOPSIS section, at the top of this document):
1079		1358
1080	Event->io (fd => IO::AIO::poll_fileno,	1359	Event->io (fd => IO::AIO::poll_fileno,
1081	poll => 'r', async => 1,	1360	poll => 'r', async => 1,
1082	cb => \&IO::AIO::poll_cb);	1361	cb => \&IO::AIO::poll_cb);
		1362
		1363	=item IO::AIO::poll_wait
		1364
		1365	If there are any outstanding requests and none of them in the result
		1366	phase, wait till the result filehandle becomes ready for reading (simply
		1367	does a C<select> on the filehandle. This is useful if you want to
		1368	synchronously wait for some requests to finish).
		1369
		1370	See C<nreqs> for an example.
		1371
		1372	=item IO::AIO::poll
		1373
		1374	Waits until some requests have been handled.
		1375
		1376	Returns the number of requests processed, but is otherwise strictly
		1377	equivalent to:
		1378
		1379	IO::AIO::poll_wait, IO::AIO::poll_cb
		1380
		1381	=item IO::AIO::flush
		1382
		1383	Wait till all outstanding AIO requests have been handled.
		1384
		1385	Strictly equivalent to:
		1386
		1387	IO::AIO::poll_wait, IO::AIO::poll_cb
		1388	while IO::AIO::nreqs;
1083		1389
1084	=item IO::AIO::max_poll_reqs $nreqs	1390	=item IO::AIO::max_poll_reqs $nreqs
1085		1391
1086	=item IO::AIO::max_poll_time $seconds	1392	=item IO::AIO::max_poll_time $seconds
1087		1393
…		…
1112	# use a low priority so other tasks have priority	1418	# use a low priority so other tasks have priority
1113	Event->io (fd => IO::AIO::poll_fileno,	1419	Event->io (fd => IO::AIO::poll_fileno,
1114	poll => 'r', nice => 1,	1420	poll => 'r', nice => 1,
1115	cb => &IO::AIO::poll_cb);	1421	cb => &IO::AIO::poll_cb);
1116		1422
1117	=item IO::AIO::poll_wait
1118
1119	If there are any outstanding requests and none of them in the result
1120	phase, wait till the result filehandle becomes ready for reading (simply
1121	does a C<select> on the filehandle. This is useful if you want to
1122	synchronously wait for some requests to finish).
1123
1124	See C<nreqs> for an example.
1125
1126	=item IO::AIO::poll
1127
1128	Waits until some requests have been handled.
1129
1130	Returns the number of requests processed, but is otherwise strictly
1131	equivalent to:
1132
1133	IO::AIO::poll_wait, IO::AIO::poll_cb
1134
1135	=item IO::AIO::flush
1136
1137	Wait till all outstanding AIO requests have been handled.
1138
1139	Strictly equivalent to:
1140
1141	IO::AIO::poll_wait, IO::AIO::poll_cb
1142	while IO::AIO::nreqs;
1143
1144	=back	1423	=back
1145		1424
1146	=head3 CONTROLLING THE NUMBER OF THREADS	1425	=head3 CONTROLLING THE NUMBER OF THREADS
1147		1426
1148	=over	1427	=over
…		…
1194		1473
1195	The default is probably ok in most situations, especially if thread	1474	The default is probably ok in most situations, especially if thread
1196	creation is fast. If thread creation is very slow on your system you might	1475	creation is fast. If thread creation is very slow on your system you might
1197	want to use larger values.	1476	want to use larger values.
1198		1477
1199	=item $oldmaxreqs = IO::AIO::max_outstanding $maxreqs	1478	=item IO::AIO::max_outstanding $maxreqs
1200		1479
1201	This is a very bad function to use in interactive programs because it	1480	This is a very bad function to use in interactive programs because it
1202	blocks, and a bad way to reduce concurrency because it is inexact: Better	1481	blocks, and a bad way to reduce concurrency because it is inexact: Better
1203	use an C<aio_group> together with a feed callback.	1482	use an C<aio_group> together with a feed callback.
1204		1483
1205	Sets the maximum number of outstanding requests to C<$nreqs>. If you	1484	Sets the maximum number of outstanding requests to C<$nreqs>. If you
1206	to queue up more than this number of requests, the next call to the	1485	do queue up more than this number of requests, the next call to the
1207	C<poll_cb> (and C<poll_some> and other functions calling C<poll_cb>)	1486	C<poll_cb> (and C<poll_some> and other functions calling C<poll_cb>)
1208	function will block until the limit is no longer exceeded.	1487	function will block until the limit is no longer exceeded.
1209		1488
1210	The default value is very large, so there is no practical limit on the	1489	The default value is very large, so there is no practical limit on the
1211	number of outstanding requests.	1490	number of outstanding requests.
1212		1491
1213	You can still queue as many requests as you want. Therefore,	1492	You can still queue as many requests as you want. Therefore,
1214	C<max_oustsanding> is mainly useful in simple scripts (with low values) or	1493	C<max_outstanding> is mainly useful in simple scripts (with low values) or
1215	as a stop gap to shield against fatal memory overflow (with large values).	1494	as a stop gap to shield against fatal memory overflow (with large values).
1216		1495
1217	=back	1496	=back
1218		1497
1219	=head3 STATISTICAL INFORMATION	1498	=head3 STATISTICAL INFORMATION
…		…
1240	Returns the number of requests currently in the pending state (executed,	1519	Returns the number of requests currently in the pending state (executed,
1241	but not yet processed by poll_cb).	1520	but not yet processed by poll_cb).
1242		1521
1243	=back	1522	=back
1244		1523
		1524	=head3 MISCELLANEOUS FUNCTIONS
		1525
		1526	IO::AIO implements some functions that might be useful, but are not
		1527	asynchronous.
		1528
		1529	=over 4
		1530
		1531	=item IO::AIO::sendfile $ofh, $ifh, $offset, $count
		1532
		1533	Calls the C<eio_sendfile_sync> function, which is like C<aio_sendfile>,
		1534	but is blocking (this makes most sense if you know the input data is
		1535	likely cached already and the output filehandle is set to non-blocking
		1536	operations).
		1537
		1538	Returns the number of bytes copied, or C<-1> on error.
		1539
		1540	=item IO::AIO::fadvise $fh, $offset, $len, $advice
		1541
		1542	Simply calls the C<posix_fadvise> function (see it's
		1543	manpage for details). The following advice constants are
		1544	avaiable: C<IO::AIO::FADV_NORMAL>, C<IO::AIO::FADV_SEQUENTIAL>,
		1545	C<IO::AIO::FADV_RANDOM>, C<IO::AIO::FADV_NOREUSE>,
		1546	C<IO::AIO::FADV_WILLNEED>, C<IO::AIO::FADV_DONTNEED>.
		1547
		1548	On systems that do not implement C<posix_fadvise>, this function returns
		1549	ENOSYS, otherwise the return value of C<posix_fadvise>.
		1550
		1551	=item IO::AIO::mmap $scalar, $length, $prot, $flags, $fh[, $offset]
		1552
		1553	Memory-maps a file (or anonymous memory range) and attaches it to the
		1554	given C<$scalar>, which will act like a string scalar.
		1555
		1556	The only operations allowed on the scalar are C<substr>/C<vec> that don't
		1557	change the string length, and most read-only operations such as copying it
		1558	or searching it with regexes and so on.
		1559
		1560	Anything else is unsafe and will, at best, result in memory leaks.
		1561
		1562	The memory map associated with the C<$scalar> is automatically removed
		1563	when the C<$scalar> is destroyed, or when the C<IO::AIO::mmap> or
		1564	C<IO::AIO::munmap> functions are called.
		1565
		1566	This calls the C<mmap>(2) function internally. See your system's manual
		1567	page for details on the C<$length>, C<$prot> and C<$flags> parameters.
		1568
		1569	The C<$length> must be larger than zero and smaller than the actual
		1570	filesize.
		1571
		1572	C<$prot> is a combination of C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_EXEC>,
		1573	C<IO::AIO::PROT_READ> and/or C<IO::AIO::PROT_WRITE>,
		1574
		1575	C<$flags> can be a combination of C<IO::AIO::MAP_SHARED> or
		1576	C<IO::AIO::MAP_PRIVATE>, or a number of system-specific flags (when
		1577	not available, the are defined as 0): C<IO::AIO::MAP_ANONYMOUS>
		1578	(which is set to C<MAP_ANON> if your system only provides this
		1579	constant), C<IO::AIO::MAP_HUGETLB>, C<IO::AIO::MAP_LOCKED>,
		1580	C<IO::AIO::MAP_NORESERVE>, C<IO::AIO::MAP_POPULATE> or
		1581	C<IO::AIO::MAP_NONBLOCK>
		1582
		1583	If C<$fh> is C<undef>, then a file descriptor of C<-1> is passed.
		1584
		1585	C<$offset> is the offset from the start of the file - it generally must be
		1586	a multiple of C<IO::AIO::PAGESIZE> and defaults to C<0>.
		1587
		1588	Example:
		1589
		1590	use Digest::MD5;
		1591	use IO::AIO;
		1592
		1593	open my $fh, "<verybigfile"
		1594	or die "$!";
		1595
		1596	IO::AIO::mmap my $data, -s $fh, IO::AIO::PROT_READ, IO::AIO::MAP_SHARED, $fh
		1597	or die "verybigfile: $!";
		1598
		1599	my $fast_md5 = md5 $data;
		1600
		1601	=item IO::AIO::munmap $scalar
		1602
		1603	Removes a previous mmap and undefines the C<$scalar>.
		1604
		1605	=item IO::AIO::mlockall $flags
		1606
		1607	Calls the C<mlockall> function with the given C<$flags> (a combination of
		1608	C<IO::AIO::MCL_CURRENT> and C<IO::AIO::MCL__FUTURE>).
		1609
		1610	On systems that do not implement C<mlockall>, this function returns
		1611	ENOSYS, otherwise the return value of C<mlockall>.
		1612
		1613	=item IO::AIO::munlockall
		1614
		1615	Calls the C<munlockall> function.
		1616
		1617	On systems that do not implement C<munlockall>, this function returns
		1618	ENOSYS, otherwise the return value of C<munlockall>.
		1619
		1620	=back
		1621
1245	=cut	1622	=cut
1246		1623
1247	# support function to convert a fd into a perl filehandle
1248	sub _fd2fh {
1249	return undef if $_[0] < 0;
1250
1251	# try to generate nice filehandles
1252	my $sym = "IO::AIO::fd#$_[0]";
1253	local *$sym;
1254
1255	open *$sym, "+<&=$_[0]" # usually works under any unix
1256	or open *$sym, "<&=$_[0]" # cygwin needs this
1257	or open *$sym, ">&=$_[0]" # or this
1258	or return undef;
1259
1260	*$sym
1261	}
1262
1263	min_parallel 8;	1624	min_parallel 8;
1264		1625
1265	END { flush }	1626	END { flush }
1266		1627
1267	1;	1628	1;
		1629
		1630	=head1 EVENT LOOP INTEGRATION
		1631
		1632	It is recommended to use L<AnyEvent::AIO> to integrate IO::AIO
		1633	automatically into many event loops:
		1634
		1635	# AnyEvent integration (EV, Event, Glib, Tk, POE, urxvt, pureperl...)
		1636	use AnyEvent::AIO;
		1637
		1638	You can also integrate IO::AIO manually into many event loops, here are
		1639	some examples of how to do this:
		1640
		1641	# EV integration
		1642	my $aio_w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb;
		1643
		1644	# Event integration
		1645	Event->io (fd => IO::AIO::poll_fileno,
		1646	poll => 'r',
		1647	cb => \&IO::AIO::poll_cb);
		1648
		1649	# Glib/Gtk2 integration
		1650	add_watch Glib::IO IO::AIO::poll_fileno,
		1651	in => sub { IO::AIO::poll_cb; 1 };
		1652
		1653	# Tk integration
		1654	Tk::Event::IO->fileevent (IO::AIO::poll_fileno, "",
		1655	readable => \&IO::AIO::poll_cb);
		1656
		1657	# Danga::Socket integration
		1658	Danga::Socket->AddOtherFds (IO::AIO::poll_fileno =>
		1659	\&IO::AIO::poll_cb);
1268		1660
1269	=head2 FORK BEHAVIOUR	1661	=head2 FORK BEHAVIOUR
1270		1662
1271	This module should do "the right thing" when the process using it forks:	1663	This module should do "the right thing" when the process using it forks:
1272		1664
…		…
1290	bytes of memory. In addition, stat requests need a stat buffer (possibly	1682	bytes of memory. In addition, stat requests need a stat buffer (possibly
1291	a few hundred bytes), readdir requires a result buffer and so on. Perl	1683	a few hundred bytes), readdir requires a result buffer and so on. Perl
1292	scalars and other data passed into aio requests will also be locked and	1684	scalars and other data passed into aio requests will also be locked and
1293	will consume memory till the request has entered the done state.	1685	will consume memory till the request has entered the done state.
1294		1686
1295	This is now awfully much, so queuing lots of requests is not usually a	1687	This is not awfully much, so queuing lots of requests is not usually a
1296	problem.	1688	problem.
1297		1689
1298	Per-thread usage:	1690	Per-thread usage:
1299		1691
1300	In the execution phase, some aio requests require more memory for	1692	In the execution phase, some aio requests require more memory for
…		…
1305		1697
1306	Known bugs will be fixed in the next release.	1698	Known bugs will be fixed in the next release.
1307		1699
1308	=head1 SEE ALSO	1700	=head1 SEE ALSO
1309		1701
1310	L<Coro::AIO>.	1702	L<AnyEvent::AIO> for easy integration into event loops, L<Coro::AIO> for a
		1703	more natural syntax.
1311		1704
1312	=head1 AUTHOR	1705	=head1 AUTHOR
1313		1706
1314	Marc Lehmann <schmorp@schmorp.de>	1707	Marc Lehmann <schmorp@schmorp.de>
1315	http://home.schmorp.de/	1708	http://home.schmorp.de/

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Comparing IO-AIO/AIO.pm (file contents): Revision 1.109 by root, Sun Jun 3 09:44:17 2007 UTC vs. Revision 1.181 by root, Tue May 4 21:14:01 2010 UTC

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Comparing IO-AIO/AIO.pm (file contents):
Revision 1.109 by root, Sun Jun 3 09:44:17 2007 UTC vs.
Revision 1.181 by root, Tue May 4 21:14:01 2010 UTC