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

Comparing IO-AIO/AIO.pm (file contents):
Revision 1.116 by root, Wed Oct 3 21:27:51 2007 UTC vs.
Revision 1.183 by root, Sun Sep 12 03:40:05 2010 UTC

…		…
4		4
5	=head1 SYNOPSIS	5	=head1 SYNOPSIS
6		6
7	use IO::AIO;	7	use IO::AIO;
8		8
9	aio_open "/etc/passwd", O_RDONLY, 0, sub {	9	aio_open "/etc/passwd", IO::AIO::O_RDONLY, 0, sub {
10	my $fh = shift	10	my $fh = shift
11	or die "/etc/passwd: $!";	11	or die "/etc/passwd: $!";
12	...	12	...
13	};	13	};
14		14
…		…
26	$req->cancel; # cancel request if still in queue	26	$req->cancel; # cancel request if still in queue
27		27
28	my $grp = aio_group sub { print "all stats done\n" };	28	my $grp = aio_group sub { print "all stats done\n" };
29	add $grp aio_stat "..." for ...;	29	add $grp aio_stat "..." for ...;
30		30
31	# AnyEvent integration
32	open my $fh, "<&=" . IO::AIO::poll_fileno or die "$!";
33	my $w = AnyEvent->io (fh => $fh, poll => 'r', cb => sub { IO::AIO::poll_cb });
34
35	# Event integration
36	Event->io (fd => IO::AIO::poll_fileno,
37	poll => 'r',
38	cb => \&IO::AIO::poll_cb);
39
40	# Glib/Gtk2 integration
41	add_watch Glib::IO IO::AIO::poll_fileno,
42	in => sub { IO::AIO::poll_cb; 1 };
43
44	# Tk integration
45	Tk::Event::IO->fileevent (IO::AIO::poll_fileno, "",
46	readable => \&IO::AIO::poll_cb);
47
48	# Danga::Socket integration
49	Danga::Socket->AddOtherFds (IO::AIO::poll_fileno =>
50	\&IO::AIO::poll_cb);
51
52	=head1 DESCRIPTION	31	=head1 DESCRIPTION
53		32
54	This module implements asynchronous I/O using whatever means your	33	This module implements asynchronous I/O using whatever means your
55	operating system supports.	34	operating system supports. It is implemented as an interface to C<libeio>
		35	(L<http://software.schmorp.de/pkg/libeio.html>).
56		36
57	Asynchronous means that operations that can normally block your program	37	Asynchronous means that operations that can normally block your program
58	(e.g. reading from disk) will be done asynchronously: the operation	38	(e.g. reading from disk) will be done asynchronously: the operation
59	will still block, but you can do something else in the meantime. This	39	will still block, but you can do something else in the meantime. This
60	is extremely useful for programs that need to stay interactive even	40	is extremely useful for programs that need to stay interactive even
…		…
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 = '2.5';	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
200	aio_chown aio_chmod aio_utime aio_truncate);	181	aio_chmod aio_utime aio_truncate
		182	aio_msync aio_mtouch aio_mlock aio_mlockall
		183	aio_statvfs);
		184
201	our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice aio_block));	185	our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice));
202	our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush	186	our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush
203	min_parallel max_parallel max_idle	187	min_parallel max_parallel max_idle
204	nreqs nready npending nthreads	188	nreqs nready npending nthreads
205	max_poll_time max_poll_reqs);	189	max_poll_time max_poll_reqs
		190	sendfile fadvise madvise
		191	mmap munmap munlock munlockall);
		192
		193	push @AIO_REQ, qw(aio_busy); # not exported
206		194
207	@IO::AIO::GRP::ISA = 'IO::AIO::REQ';	195	@IO::AIO::GRP::ISA = 'IO::AIO::REQ';
208		196
209	require XSLoader;	197	require XSLoader;
210	XSLoader::load ("IO::AIO", $VERSION);	198	XSLoader::load ("IO::AIO", $VERSION);
211	}	199	}
212		200
213	=head1 FUNCTIONS	201	=head1 FUNCTIONS
		202
		203	=head2 QUICK OVERVIEW
		204
		205	This section simply lists the prototypes of the most important functions
		206	for quick reference. See the following sections for function-by-function
		207	documentation.
		208
		209	aio_open $pathname, $flags, $mode, $callback->($fh)
		210	aio_close $fh, $callback->($status)
		211	aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
		212	aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
		213	aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval)
		214	aio_readahead $fh,$offset,$length, $callback->($retval)
		215	aio_stat $fh_or_path, $callback->($status)
		216	aio_lstat $fh, $callback->($status)
		217	aio_statvfs $fh_or_path, $callback->($statvfs)
		218	aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
		219	aio_chown $fh_or_path, $uid, $gid, $callback->($status)
		220	aio_truncate $fh_or_path, $offset, $callback->($status)
		221	aio_chmod $fh_or_path, $mode, $callback->($status)
		222	aio_unlink $pathname, $callback->($status)
		223	aio_mknod $path, $mode, $dev, $callback->($status)
		224	aio_link $srcpath, $dstpath, $callback->($status)
		225	aio_symlink $srcpath, $dstpath, $callback->($status)
		226	aio_readlink $path, $callback->($link)
		227	aio_rename $srcpath, $dstpath, $callback->($status)
		228	aio_mkdir $pathname, $mode, $callback->($status)
		229	aio_rmdir $pathname, $callback->($status)
		230	aio_readdir $pathname, $callback->($entries)
		231	aio_readdirx $pathname, $flags, $callback->($entries, $flags)
		232	IO::AIO::READDIR_DENTS IO::AIO::READDIR_DIRS_FIRST
		233	IO::AIO::READDIR_STAT_ORDER IO::AIO::READDIR_FOUND_UNKNOWN
		234	aio_load $path, $data, $callback->($status)
		235	aio_copy $srcpath, $dstpath, $callback->($status)
		236	aio_move $srcpath, $dstpath, $callback->($status)
		237	aio_scandir $path, $maxreq, $callback->($dirs, $nondirs)
		238	aio_rmtree $path, $callback->($status)
		239	aio_sync $callback->($status)
		240	aio_fsync $fh, $callback->($status)
		241	aio_fdatasync $fh, $callback->($status)
		242	aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status)
		243	aio_pathsync $path, $callback->($status)
		244	aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
		245	aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
		246	aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status)
		247	aio_mlockall $flags, $callback->($status)
		248	aio_group $callback->(...)
		249	aio_nop $callback->()
		250
		251	$prev_pri = aioreq_pri [$pri]
		252	aioreq_nice $pri_adjust
		253
		254	IO::AIO::poll_wait
		255	IO::AIO::poll_cb
		256	IO::AIO::poll
		257	IO::AIO::flush
		258	IO::AIO::max_poll_reqs $nreqs
		259	IO::AIO::max_poll_time $seconds
		260	IO::AIO::min_parallel $nthreads
		261	IO::AIO::max_parallel $nthreads
		262	IO::AIO::max_idle $nthreads
		263	IO::AIO::max_outstanding $maxreqs
		264	IO::AIO::nreqs
		265	IO::AIO::nready
		266	IO::AIO::npending
		267
		268	IO::AIO::sendfile $ofh, $ifh, $offset, $count
		269	IO::AIO::fadvise $fh, $offset, $len, $advice
		270	IO::AIO::munlock $scalar, $offset = 0, $length = undef
		271	IO::AIO::munlockall
214		272
215	=head2 AIO REQUEST FUNCTIONS	273	=head2 AIO REQUEST FUNCTIONS
216		274
217	All the C<aio_*> calls are more or less thin wrappers around the syscall	275	All the C<aio_*> calls are more or less thin wrappers around the syscall
218	with the same name (sans C<aio_>). The arguments are similar or identical,	276	with the same name (sans C<aio_>). The arguments are similar or identical,
219	and they all accept an additional (and optional) C<$callback> argument	277	and they all accept an additional (and optional) C<$callback> argument
220	which must be a code reference. This code reference will get called with	278	which must be a code reference. This code reference will get called with
221	the syscall return code (e.g. most syscalls return C<-1> on error, unlike	279	the syscall return code (e.g. most syscalls return C<-1> on error, unlike
222	perl, which usually delivers "false") as it's sole argument when the given	280	perl, which usually delivers "false") as its sole argument after the given
223	syscall has been executed asynchronously.	281	syscall has been executed asynchronously.
224		282
225	All functions expecting a filehandle keep a copy of the filehandle	283	All functions expecting a filehandle keep a copy of the filehandle
226	internally until the request has finished.	284	internally until the request has finished.
227		285
…		…
241	your pathnames to the locale (or other) encoding in effect in the user	299	your pathnames to the locale (or other) encoding in effect in the user
242	environment, d) use Glib::filename_from_unicode on unicode filenames or e)	300	environment, d) use Glib::filename_from_unicode on unicode filenames or e)
243	use something else to ensure your scalar has the correct contents.	301	use something else to ensure your scalar has the correct contents.
244		302
245	This works, btw. independent of the internal UTF-8 bit, which IO::AIO	303	This works, btw. independent of the internal UTF-8 bit, which IO::AIO
246	handles correctly wether it is set or not.	304	handles correctly whether it is set or not.
247		305
248	=over 4	306	=over 4
249		307
250	=item $prev_pri = aioreq_pri [$pri]	308	=item $prev_pri = aioreq_pri [$pri]
251		309
…		…
298	by the umask in effect then the request is being executed, so better never	356	by the umask in effect then the request is being executed, so better never
299	change the umask.	357	change the umask.
300		358
301	Example:	359	Example:
302		360
303	aio_open "/etc/passwd", O_RDONLY, 0, sub {	361	aio_open "/etc/passwd", IO::AIO::O_RDONLY, 0, sub {
304	if ($_[0]) {	362	if ($_[0]) {
305	print "open successful, fh is $_[0]\n";	363	print "open successful, fh is $_[0]\n";
306	...	364	...
307	} else {	365	} else {
308	die "open failed: $!\n";	366	die "open failed: $!\n";
…		…
313	=item aio_close $fh, $callback->($status)	371	=item aio_close $fh, $callback->($status)
314		372
315	Asynchronously close a file and call the callback with the result	373	Asynchronously close a file and call the callback with the result
316	code.	374	code.
317		375
318	Unlike the other functions operating on files, this function uses the	376	Unfortunately, you can't do this to perl. Perl I<insists> very strongly on
319	PerlIO layer to close the filehandle. The reason is that the PerlIO API	377	closing the file descriptor associated with the filehandle itself.
320	insists on closing the underlying fd itself, no matter what, and doesn't
321	allow modifications to the fd. Unfortunately, it is not clear that you can
322	call PerlIO from different threads (actually, its quite clear that this
323	won't work in some cases), so while it likely works perfectly with simple
324	file handles (such as the ones created by C<aio_open>) it might fail in
325	interesting ways for others.
326		378
327	Having said that, aio_close tries to clean up the filehandle as much as	379	Therefore, C<aio_close> will not close the filehandle - instead it will
328	possible before handing it to an io thread, and generally does work.	380	use dup2 to overwrite the file descriptor with the write-end of a pipe
		381	(the pipe fd will be created on demand and will be cached).
329		382
		383	Or in other words: the file descriptor will be closed, but it will not be
		384	free for reuse until the perl filehandle is closed.
		385
		386	=cut
330		387
331	=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)	388	=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
332		389
333	=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)	390	=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
334		391
335	Reads or writes C<$length> bytes from the specified C<$fh> and C<$offset>	392	Reads or writes C<$length> bytes from or to the specified C<$fh> and
336	into the scalar given by C<$data> and offset C<$dataoffset> and calls the	393	C<$offset> into the scalar given by C<$data> and offset C<$dataoffset>
337	callback without the actual number of bytes read (or -1 on error, just	394	and calls the callback without the actual number of bytes read (or -1 on
338	like the syscall).	395	error, just like the syscall).
		396
		397	C<aio_read> will, like C<sysread>, shrink or grow the C<$data> scalar to
		398	offset plus the actual number of bytes read.
339		399
340	If C<$offset> is undefined, then the current file descriptor offset will	400	If C<$offset> is undefined, then the current file descriptor offset will
341	be used (and updated), otherwise the file descriptor offset will not be	401	be used (and updated), otherwise the file descriptor offset will not be
342	changed by these calls.	402	changed by these calls.
343		403
344	If C<$length> is undefined in C<aio_write>, use the remaining length of C<$data>.	404	If C<$length> is undefined in C<aio_write>, use the remaining length of
		405	C<$data>.
345		406
346	If C<$dataoffset> is less than zero, it will be counted from the end of	407	If C<$dataoffset> is less than zero, it will be counted from the end of
347	C<$data>.	408	C<$data>.
348		409
349	The C<$data> scalar I<MUST NOT> be modified in any way while the request	410	The C<$data> scalar I<MUST NOT> be modified in any way while the request
…		…
367	than one C<aio_sendfile> per C<$out_fh>, as they will interfere with each	428	than one C<aio_sendfile> per C<$out_fh>, as they will interfere with each
368	other.	429	other.
369		430
370	This call tries to make use of a native C<sendfile> syscall to provide	431	This call tries to make use of a native C<sendfile> syscall to provide
371	zero-copy operation. For this to work, C<$out_fh> should refer to a	432	zero-copy operation. For this to work, C<$out_fh> should refer to a
372	socket, and C<$in_fh> should refer to mmap'able file.	433	socket, and C<$in_fh> should refer to an mmap'able file.
373		434
374	If the native sendfile call fails or is not implemented, it will be	435	If a native sendfile cannot be found or it fails with C<ENOSYS>,
		436	C<ENOTSUP>, C<EOPNOTSUPP>, C<EAFNOSUPPORT>, C<EPROTOTYPE> or C<ENOTSOCK>,
375	emulated, so you can call C<aio_sendfile> on any type of filehandle	437	it will be emulated, so you can call C<aio_sendfile> on any type of
376	regardless of the limitations of the operating system.	438	filehandle regardless of the limitations of the operating system.
377		439
378	Please note, however, that C<aio_sendfile> can read more bytes from	440	Please note, however, that C<aio_sendfile> can read more bytes from
379	C<$in_fh> than are written, and there is no way to find out how many	441	C<$in_fh> than are written, and there is no way to find out how many
380	bytes have been read from C<aio_sendfile> alone, as C<aio_sendfile> only	442	bytes have been read from C<aio_sendfile> alone, as C<aio_sendfile> only
381	provides the number of bytes written to C<$out_fh>. Only if the result	443	provides the number of bytes written to C<$out_fh>. Only if the result
…		…
419	$_[0] and die "stat failed: $!";	481	$_[0] and die "stat failed: $!";
420	print "size is ", -s _, "\n";	482	print "size is ", -s _, "\n";
421	};	483	};
422		484
423		485
		486	=item aio_statvfs $fh_or_path, $callback->($statvfs)
		487
		488	Works like the POSIX C<statvfs> or C<fstatvfs> syscalls, depending on
		489	whether a file handle or path was passed.
		490
		491	On success, the callback is passed a hash reference with the following
		492	members: C<bsize>, C<frsize>, C<blocks>, C<bfree>, C<bavail>, C<files>,
		493	C<ffree>, C<favail>, C<fsid>, C<flag> and C<namemax>. On failure, C<undef>
		494	is passed.
		495
		496	The following POSIX IO::AIO::ST_* constants are defined: C<ST_RDONLY> and
		497	C<ST_NOSUID>.
		498
		499	The following non-POSIX IO::AIO::ST_* flag masks are defined to
		500	their correct value when available, or to C<0> on systems that do
		501	not support them: C<ST_NODEV>, C<ST_NOEXEC>, C<ST_SYNCHRONOUS>,
		502	C<ST_MANDLOCK>, C<ST_WRITE>, C<ST_APPEND>, C<ST_IMMUTABLE>, C<ST_NOATIME>,
		503	C<ST_NODIRATIME> and C<ST_RELATIME>.
		504
		505	Example: stat C</wd> and dump out the data if successful.
		506
		507	aio_statvfs "/wd", sub {
		508	my $f = $_[0]
		509	or die "statvfs: $!";
		510
		511	use Data::Dumper;
		512	say Dumper $f;
		513	};
		514
		515	# result:
		516	{
		517	bsize => 1024,
		518	bfree => 4333064312,
		519	blocks => 10253828096,
		520	files => 2050765568,
		521	flag => 4096,
		522	favail => 2042092649,
		523	bavail => 4333064312,
		524	ffree => 2042092649,
		525	namemax => 255,
		526	frsize => 1024,
		527	fsid => 1810
		528	}
		529
		530
424	=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status)	531	=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
425		532
426	Works like perl's C<utime> function (including the special case of $atime	533	Works like perl's C<utime> function (including the special case of $atime
427	and $mtime being undef). Fractional times are supported if the underlying	534	and $mtime being undef). Fractional times are supported if the underlying
428	syscalls support them.	535	syscalls support them.
…		…
521		628
522	Unlike the POSIX call of the same name, C<aio_readdir> reads an entire	629	Unlike the POSIX call of the same name, C<aio_readdir> reads an entire
523	directory (i.e. opendir + readdir + closedir). The entries will not be	630	directory (i.e. opendir + readdir + closedir). The entries will not be
524	sorted, and will B<NOT> include the C<.> and C<..> entries.	631	sorted, and will B<NOT> include the C<.> and C<..> entries.
525		632
526	The callback a single argument which is either C<undef> or an array-ref	633	The callback is passed a single argument which is either C<undef> or an
527	with the filenames.	634	array-ref with the filenames.
		635
		636
		637	=item aio_readdirx $pathname, $flags, $callback->($entries, $flags)
		638
		639	Quite similar to C<aio_readdir>, but the C<$flags> argument allows to tune
		640	behaviour and output format. In case of an error, C<$entries> will be
		641	C<undef>.
		642
		643	The flags are a combination of the following constants, ORed together (the
		644	flags will also be passed to the callback, possibly modified):
		645
		646	=over 4
		647
		648	=item IO::AIO::READDIR_DENTS
		649
		650	When this flag is off, then the callback gets an arrayref with of names
		651	only (as with C<aio_readdir>), otherwise it gets an arrayref with
		652	C<[$name, $type, $inode]> arrayrefs, each describing a single directory
		653	entry in more detail.
		654
		655	C<$name> is the name of the entry.
		656
		657	C<$type> is one of the C<IO::AIO::DT_xxx> constants:
		658
		659	C<IO::AIO::DT_UNKNOWN>, C<IO::AIO::DT_FIFO>, C<IO::AIO::DT_CHR>, C<IO::AIO::DT_DIR>,
		660	C<IO::AIO::DT_BLK>, C<IO::AIO::DT_REG>, C<IO::AIO::DT_LNK>, C<IO::AIO::DT_SOCK>,
		661	C<IO::AIO::DT_WHT>.
		662
		663	C<IO::AIO::DT_UNKNOWN> means just that: readdir does not know. If you need to
		664	know, you have to run stat yourself. Also, for speed reasons, the C<$type>
		665	scalars are read-only: you can not modify them.
		666
		667	C<$inode> is the inode number (which might not be exact on systems with 64
		668	bit inode numbers and 32 bit perls). This field has unspecified content on
		669	systems that do not deliver the inode information.
		670
		671	=item IO::AIO::READDIR_DIRS_FIRST
		672
		673	When this flag is set, then the names will be returned in an order where
		674	likely directories come first. This is useful when you need to quickly
		675	find directories, or you want to find all directories while avoiding to
		676	stat() each entry.
		677
		678	If the system returns type information in readdir, then this is used
		679	to find directories directly. Otherwise, likely directories are files
		680	beginning with ".", or otherwise files with no dots, of which files with
		681	short names are tried first.
		682
		683	=item IO::AIO::READDIR_STAT_ORDER
		684
		685	When this flag is set, then the names will be returned in an order
		686	suitable for stat()'ing each one. That is, when you plan to stat()
		687	all files in the given directory, then the returned order will likely
		688	be fastest.
		689
		690	If both this flag and C<IO::AIO::READDIR_DIRS_FIRST> are specified, then
		691	the likely dirs come first, resulting in a less optimal stat order.
		692
		693	=item IO::AIO::READDIR_FOUND_UNKNOWN
		694
		695	This flag should not be set when calling C<aio_readdirx>. Instead, it
		696	is being set by C<aio_readdirx>, when any of the C<$type>'s found were
		697	C<IO::AIO::DT_UNKNOWN>. The absense of this flag therefore indicates that all
		698	C<$type>'s are known, which can be used to speed up some algorithms.
		699
		700	=back
528		701
529		702
530	=item aio_load $path, $data, $callback->($status)	703	=item aio_load $path, $data, $callback->($status)
531		704
532	This is a composite request that tries to fully load the given file into	705	This is a composite request that tries to fully load the given file into
533	memory. Status is the same as with aio_read.	706	memory. Status is the same as with aio_read.
534		707
535	=cut	708	=cut
536		709
537	sub aio_load($$;$) {	710	sub aio_load($$;$) {
538	aio_block {
539	my ($path, undef, $cb) = @_;	711	my ($path, undef, $cb) = @_;
540	my $data = \$_[1];	712	my $data = \$_[1];
541		713
542	my $pri = aioreq_pri;	714	my $pri = aioreq_pri;
543	my $grp = aio_group $cb;	715	my $grp = aio_group $cb;
		716
		717	aioreq_pri $pri;
		718	add $grp aio_open $path, O_RDONLY, 0, sub {
		719	my $fh = shift
		720	or return $grp->result (-1);
544		721
545	aioreq_pri $pri;	722	aioreq_pri $pri;
546	add $grp aio_open $path, O_RDONLY, 0, sub {
547	my $fh = shift
548	or return $grp->result (-1);
549
550	aioreq_pri $pri;
551	add $grp aio_read $fh, 0, (-s $fh), $$data, 0, sub {	723	add $grp aio_read $fh, 0, (-s $fh), $$data, 0, sub {
552	$grp->result ($_[0]);	724	$grp->result ($_[0]);
553	};
554	};	725	};
555
556	$grp
557	}	726	};
		727
		728	$grp
558	}	729	}
559		730
560	=item aio_copy $srcpath, $dstpath, $callback->($status)	731	=item aio_copy $srcpath, $dstpath, $callback->($status)
561		732
562	Try to copy the I<file> (directories not supported as either source or	733	Try to copy the I<file> (directories not supported as either source or
563	destination) from C<$srcpath> to C<$dstpath> and call the callback with	734	destination) from C<$srcpath> to C<$dstpath> and call the callback with
564	the C<0> (error) or C<-1> ok.	735	a status of C<0> (ok) or C<-1> (error, see C<$!>).
565		736
566	This is a composite request that it creates the destination file with	737	This is a composite request that creates the destination file with
567	mode 0200 and copies the contents of the source file into it using	738	mode 0200 and copies the contents of the source file into it using
568	C<aio_sendfile>, followed by restoring atime, mtime, access mode and	739	C<aio_sendfile>, followed by restoring atime, mtime, access mode and
569	uid/gid, in that order.	740	uid/gid, in that order.
570		741
571	If an error occurs, the partial destination file will be unlinked, if	742	If an error occurs, the partial destination file will be unlinked, if
…		…
573	errors are being ignored.	744	errors are being ignored.
574		745
575	=cut	746	=cut
576		747
577	sub aio_copy($$;$) {	748	sub aio_copy($$;$) {
578	aio_block {
579	my ($src, $dst, $cb) = @_;	749	my ($src, $dst, $cb) = @_;
580		750
581	my $pri = aioreq_pri;	751	my $pri = aioreq_pri;
582	my $grp = aio_group $cb;	752	my $grp = aio_group $cb;
583		753
584	aioreq_pri $pri;	754	aioreq_pri $pri;
585	add $grp aio_open $src, O_RDONLY, 0, sub {	755	add $grp aio_open $src, O_RDONLY, 0, sub {
586	if (my $src_fh = $_[0]) {	756	if (my $src_fh = $_[0]) {
587	my @stat = stat $src_fh;	757	my @stat = stat $src_fh; # hmm, might block over nfs?
588		758
589	aioreq_pri $pri;	759	aioreq_pri $pri;
590	add $grp aio_open $dst, O_CREAT \| O_WRONLY \| O_TRUNC, 0200, sub {	760	add $grp aio_open $dst, O_CREAT \| O_WRONLY \| O_TRUNC, 0200, sub {
591	if (my $dst_fh = $_[0]) {	761	if (my $dst_fh = $_[0]) {
592	aioreq_pri $pri;	762	aioreq_pri $pri;
593	add $grp aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub {	763	add $grp aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub {
594	if ($_[0] == $stat[7]) {	764	if ($_[0] == $stat[7]) {
595	$grp->result (0);	765	$grp->result (0);
596	close $src_fh;	766	close $src_fh;
597		767
598	# those should not normally block. should. should.
599	utime $stat[8], $stat[9], $dst;
600	chmod $stat[2] & 07777, $dst_fh;
601	chown $stat[4], $stat[5], $dst_fh;
602	close $dst_fh;
603	} else {	768	my $ch = sub {
604	$grp->result (-1);
605	close $src_fh;
606	close $dst_fh;
607
608	aioreq $pri;	769	aioreq_pri $pri;
		770	add $grp aio_chmod $dst_fh, $stat[2] & 07777, sub {
		771	aioreq_pri $pri;
		772	add $grp aio_chown $dst_fh, $stat[4], $stat[5], sub {
		773	aioreq_pri $pri;
609	add $grp aio_unlink $dst;	774	add $grp aio_close $dst_fh;
		775	}
		776	};
610	}	777	};
		778
		779	aioreq_pri $pri;
		780	add $grp aio_utime $dst_fh, $stat[8], $stat[9], sub {
		781	if ($_[0] < 0 && $! == ENOSYS) {
		782	aioreq_pri $pri;
		783	add $grp aio_utime $dst, $stat[8], $stat[9], $ch;
		784	} else {
		785	$ch->();
		786	}
		787	};
		788	} else {
		789	$grp->result (-1);
		790	close $src_fh;
		791	close $dst_fh;
		792
		793	aioreq $pri;
		794	add $grp aio_unlink $dst;
611	};	795	}
612	} else {
613	$grp->result (-1);
614	}	796	};
		797	} else {
		798	$grp->result (-1);
615	},	799	}
616
617	} else {
618	$grp->result (-1);
619	}	800	},
		801
		802	} else {
		803	$grp->result (-1);
620	};	804	}
621
622	$grp
623	}	805	};
		806
		807	$grp
624	}	808	}
625		809
626	=item aio_move $srcpath, $dstpath, $callback->($status)	810	=item aio_move $srcpath, $dstpath, $callback->($status)
627		811
628	Try to move the I<file> (directories not supported as either source or	812	Try to move the I<file> (directories not supported as either source or
629	destination) from C<$srcpath> to C<$dstpath> and call the callback with	813	destination) from C<$srcpath> to C<$dstpath> and call the callback with
630	the C<0> (error) or C<-1> ok.	814	a status of C<0> (ok) or C<-1> (error, see C<$!>).
631		815
632	This is a composite request that tries to rename(2) the file first. If	816	This is a composite request that tries to rename(2) the file first; if
633	rename files with C<EXDEV>, it copies the file with C<aio_copy> and, if	817	rename fails with C<EXDEV>, it copies the file with C<aio_copy> and, if
634	that is successful, unlinking the C<$srcpath>.	818	that is successful, unlinks the C<$srcpath>.
635		819
636	=cut	820	=cut
637		821
638	sub aio_move($$;$) {	822	sub aio_move($$;$) {
639	aio_block {
640	my ($src, $dst, $cb) = @_;	823	my ($src, $dst, $cb) = @_;
641		824
642	my $pri = aioreq_pri;	825	my $pri = aioreq_pri;
643	my $grp = aio_group $cb;	826	my $grp = aio_group $cb;
644		827
645	aioreq_pri $pri;	828	aioreq_pri $pri;
646	add $grp aio_rename $src, $dst, sub {	829	add $grp aio_rename $src, $dst, sub {
647	if ($_[0] && $! == EXDEV) {	830	if ($_[0] && $! == EXDEV) {
648	aioreq_pri $pri;	831	aioreq_pri $pri;
649	add $grp aio_copy $src, $dst, sub {	832	add $grp aio_copy $src, $dst, sub {
650	$grp->result ($_[0]);
651
652	if (!$_[0]) {
653	aioreq_pri $pri;
654	add $grp aio_unlink $src;
655	}
656	};
657	} else {
658	$grp->result ($_[0]);	833	$grp->result ($_[0]);
		834
		835	if (!$_[0]) {
		836	aioreq_pri $pri;
		837	add $grp aio_unlink $src;
		838	}
659	}	839	};
		840	} else {
		841	$grp->result ($_[0]);
660	};	842	}
661
662	$grp
663	}	843	};
		844
		845	$grp
664	}	846	}
665		847
666	=item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs)	848	=item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs)
667		849
668	Scans a directory (similar to C<aio_readdir>) but additionally tries to	850	Scans a directory (similar to C<aio_readdir>) but additionally tries to
…		…
688		870
689	Implementation notes.	871	Implementation notes.
690		872
691	The C<aio_readdir> cannot be avoided, but C<stat()>'ing every entry can.	873	The C<aio_readdir> cannot be avoided, but C<stat()>'ing every entry can.
692		874
		875	If readdir returns file type information, then this is used directly to
		876	find directories.
		877
693	After reading the directory, the modification time, size etc. of the	878	Otherwise, after reading the directory, the modification time, size etc.
694	directory before and after the readdir is checked, and if they match (and	879	of the directory before and after the readdir is checked, and if they
695	isn't the current time), the link count will be used to decide how many	880	match (and isn't the current time), the link count will be used to decide
696	entries are directories (if >= 2). Otherwise, no knowledge of the number	881	how many entries are directories (if >= 2). Otherwise, no knowledge of the
697	of subdirectories will be assumed.	882	number of subdirectories will be assumed.
698		883
699	Then entries will be sorted into likely directories (everything without	884	Then entries will be sorted into likely directories a non-initial dot
700	a non-initial dot currently) and likely non-directories (everything	885	currently) and likely non-directories (see C<aio_readdirx>). Then every
701	else). Then every entry plus an appended C</.> will be C<stat>'ed,	886	entry plus an appended C</.> will be C<stat>'ed, likely directories first,
702	likely directories first. If that succeeds, it assumes that the entry	887	in order of their inode numbers. If that succeeds, it assumes that the
703	is a directory or a symlink to directory (which will be checked	888	entry is a directory or a symlink to directory (which will be checked
704	seperately). This is often faster than stat'ing the entry itself because	889	seperately). This is often faster than stat'ing the entry itself because
705	filesystems might detect the type of the entry without reading the inode	890	filesystems might detect the type of the entry without reading the inode
706	data (e.g. ext2fs filetype feature).	891	data (e.g. ext2fs filetype feature), even on systems that cannot return
		892	the filetype information on readdir.
707		893
708	If the known number of directories (link count - 2) has been reached, the	894	If the known number of directories (link count - 2) has been reached, the
709	rest of the entries is assumed to be non-directories.	895	rest of the entries is assumed to be non-directories.
710		896
711	This only works with certainty on POSIX (= UNIX) filesystems, which	897	This only works with certainty on POSIX (= UNIX) filesystems, which
…		…
716	directory counting heuristic.	902	directory counting heuristic.
717		903
718	=cut	904	=cut
719		905
720	sub aio_scandir($$;$) {	906	sub aio_scandir($$;$) {
721	aio_block {
722	my ($path, $maxreq, $cb) = @_;	907	my ($path, $maxreq, $cb) = @_;
723		908
724	my $pri = aioreq_pri;	909	my $pri = aioreq_pri;
725		910
726	my $grp = aio_group $cb;	911	my $grp = aio_group $cb;
727		912
728	$maxreq = 4 if $maxreq <= 0;	913	$maxreq = 4 if $maxreq <= 0;
729		914
730	# stat once	915	# stat once
		916	aioreq_pri $pri;
		917	add $grp aio_stat $path, sub {
		918	return $grp->result () if $_[0];
		919	my $now = time;
		920	my $hash1 = join ":", (stat _)[0,1,3,7,9];
		921
		922	# read the directory entries
731	aioreq_pri $pri;	923	aioreq_pri $pri;
732	add $grp aio_stat $path, sub {	924	add $grp aio_readdirx $path, READDIR_DIRS_FIRST, sub {
		925	my $entries = shift
733	return $grp->result () if $_[0];	926	or return $grp->result ();
734	my $now = time;
735	my $hash1 = join ":", (stat _)[0,1,3,7,9];
736		927
737	# read the directory entries	928	# stat the dir another time
738	aioreq_pri $pri;	929	aioreq_pri $pri;
739	add $grp aio_readdir $path, sub {
740	my $entries = shift
741	or return $grp->result ();
742
743	# stat the dir another time
744	aioreq_pri $pri;
745	add $grp aio_stat $path, sub {	930	add $grp aio_stat $path, sub {
746	my $hash2 = join ":", (stat _)[0,1,3,7,9];	931	my $hash2 = join ":", (stat _)[0,1,3,7,9];
747		932
748	my $ndirs;	933	my $ndirs;
749		934
750	# take the slow route if anything looks fishy	935	# take the slow route if anything looks fishy
751	if ($hash1 ne $hash2 or (stat _)[9] == $now) {	936	if ($hash1 ne $hash2 or (stat _)[9] == $now) {
752	$ndirs = -1;	937	$ndirs = -1;
753	} else {	938	} else {
754	# if nlink == 2, we are finished	939	# if nlink == 2, we are finished
755	# on non-posix-fs's, we rely on nlink < 2	940	# for non-posix-fs's, we rely on nlink < 2
756	$ndirs = (stat _)[3] - 2	941	$ndirs = (stat _)[3] - 2
757	or return $grp->result ([], $entries);	942	or return $grp->result ([], $entries);
758	}	943	}
759		944
760	# sort into likely dirs and likely nondirs
761	# dirs == files without ".", short entries first
762	$entries = [map $_->[0],
763	sort { $b->[1] cmp $a->[1] }
764	map [$_, sprintf "%s%04d", (/.\./ ? "1" : "0"), length],
765	@$entries];
766
767	my (@dirs, @nondirs);	945	my (@dirs, @nondirs);
768		946
769	my $statgrp = add $grp aio_group sub {	947	my $statgrp = add $grp aio_group sub {
770	$grp->result (\@dirs, \@nondirs);	948	$grp->result (\@dirs, \@nondirs);
771	};	949	};
772		950
773	limit $statgrp $maxreq;	951	limit $statgrp $maxreq;
774	feed $statgrp sub {	952	feed $statgrp sub {
775	return unless @$entries;	953	return unless @$entries;
776	my $entry = pop @$entries;	954	my $entry = shift @$entries;
777		955
778	aioreq_pri $pri;	956	aioreq_pri $pri;
779	add $statgrp aio_stat "$path/$entry/.", sub {	957	add $statgrp aio_stat "$path/$entry/.", sub {
780	if ($_[0] < 0) {	958	if ($_[0] < 0) {
781	push @nondirs, $entry;	959	push @nondirs, $entry;
782	} else {	960	} else {
783	# need to check for real directory	961	# need to check for real directory
784	aioreq_pri $pri;	962	aioreq_pri $pri;
785	add $statgrp aio_lstat "$path/$entry", sub {	963	add $statgrp aio_lstat "$path/$entry", sub {
786	if (-d _) {	964	if (-d _) {
787	push @dirs, $entry;	965	push @dirs, $entry;
788		966
789	unless (--$ndirs) {	967	unless (--$ndirs) {
790	push @nondirs, @$entries;	968	push @nondirs, @$entries;
791	feed $statgrp;	969	feed $statgrp;
792	}
793	} else {
794	push @nondirs, $entry;
795	}	970	}
		971	} else {
		972	push @nondirs, $entry;
796	}	973	}
797	}	974	}
798	};	975	}
799	};	976	};
800	};	977	};
801	};	978	};
802	};	979	};
803
804	$grp
805	}	980	};
		981
		982	$grp
806	}	983	}
807		984
808	=item aio_rmtree $path, $callback->($status)	985	=item aio_rmtree $path, $callback->($status)
809		986
810	Delete a directory tree starting (and including) C<$path>, return the	987	Delete a directory tree starting (and including) C<$path>, return the
…		…
814		991
815	=cut	992	=cut
816		993
817	sub aio_rmtree;	994	sub aio_rmtree;
818	sub aio_rmtree($;$) {	995	sub aio_rmtree($;$) {
819	aio_block {
820	my ($path, $cb) = @_;	996	my ($path, $cb) = @_;
821		997
822	my $pri = aioreq_pri;	998	my $pri = aioreq_pri;
823	my $grp = aio_group $cb;	999	my $grp = aio_group $cb;
824		1000
825	aioreq_pri $pri;	1001	aioreq_pri $pri;
826	add $grp aio_scandir $path, 0, sub {	1002	add $grp aio_scandir $path, 0, sub {
827	my ($dirs, $nondirs) = @_;	1003	my ($dirs, $nondirs) = @_;
828		1004
829	my $dirgrp = aio_group sub {	1005	my $dirgrp = aio_group sub {
830	add $grp aio_rmdir $path, sub {	1006	add $grp aio_rmdir $path, sub {
831	$grp->result ($_[0]);	1007	$grp->result ($_[0]);
832	};
833	};	1008	};
834
835	(aioreq_pri $pri), add $dirgrp aio_rmtree "$path/$_" for @$dirs;
836	(aioreq_pri $pri), add $dirgrp aio_unlink "$path/$_" for @$nondirs;
837
838	add $grp $dirgrp;
839	};	1009	};
840		1010
841	$grp	1011	(aioreq_pri $pri), add $dirgrp aio_rmtree "$path/$_" for @$dirs;
		1012	(aioreq_pri $pri), add $dirgrp aio_unlink "$path/$_" for @$nondirs;
		1013
		1014	add $grp $dirgrp;
842	}	1015	};
		1016
		1017	$grp
843	}	1018	}
		1019
		1020	=item aio_sync $callback->($status)
		1021
		1022	Asynchronously call sync and call the callback when finished.
844		1023
845	=item aio_fsync $fh, $callback->($status)	1024	=item aio_fsync $fh, $callback->($status)
846		1025
847	Asynchronously call fsync on the given filehandle and call the callback	1026	Asynchronously call fsync on the given filehandle and call the callback
848	with the fsync result code.	1027	with the fsync result code.
…		…
852	Asynchronously call fdatasync on the given filehandle and call the	1031	Asynchronously call fdatasync on the given filehandle and call the
853	callback with the fdatasync result code.	1032	callback with the fdatasync result code.
854		1033
855	If this call isn't available because your OS lacks it or it couldn't be	1034	If this call isn't available because your OS lacks it or it couldn't be
856	detected, it will be emulated by calling C<fsync> instead.	1035	detected, it will be emulated by calling C<fsync> instead.
		1036
		1037	=item aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status)
		1038
		1039	Sync the data portion of the file specified by C<$offset> and C<$length>
		1040	to disk (but NOT the metadata), by calling the Linux-specific
		1041	sync_file_range call. If sync_file_range is not available or it returns
		1042	ENOSYS, then fdatasync or fsync is being substituted.
		1043
		1044	C<$flags> can be a combination of C<IO::AIO::SYNC_FILE_RANGE_WAIT_BEFORE>,
		1045	C<IO::AIO::SYNC_FILE_RANGE_WRITE> and
		1046	C<IO::AIO::SYNC_FILE_RANGE_WAIT_AFTER>: refer to the sync_file_range
		1047	manpage for details.
		1048
		1049	=item aio_pathsync $path, $callback->($status)
		1050
		1051	This request tries to open, fsync and close the given path. This is a
		1052	composite request intended to sync directories after directory operations
		1053	(E.g. rename). This might not work on all operating systems or have any
		1054	specific effect, but usually it makes sure that directory changes get
		1055	written to disc. It works for anything that can be opened for read-only,
		1056	not just directories.
		1057
		1058	Future versions of this function might fall back to other methods when
		1059	C<fsync> on the directory fails (such as calling C<sync>).
		1060
		1061	Passes C<0> when everything went ok, and C<-1> on error.
		1062
		1063	=cut
		1064
		1065	sub aio_pathsync($;$) {
		1066	my ($path, $cb) = @_;
		1067
		1068	my $pri = aioreq_pri;
		1069	my $grp = aio_group $cb;
		1070
		1071	aioreq_pri $pri;
		1072	add $grp aio_open $path, O_RDONLY, 0, sub {
		1073	my ($fh) = @_;
		1074	if ($fh) {
		1075	aioreq_pri $pri;
		1076	add $grp aio_fsync $fh, sub {
		1077	$grp->result ($_[0]);
		1078
		1079	aioreq_pri $pri;
		1080	add $grp aio_close $fh;
		1081	};
		1082	} else {
		1083	$grp->result (-1);
		1084	}
		1085	};
		1086
		1087	$grp
		1088	}
		1089
		1090	=item aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
		1091
		1092	This is a rather advanced IO::AIO call, which only works on mmap(2)ed
		1093	scalars (see the C<IO::AIO::mmap> function, although it also works on data
		1094	scalars managed by the L<Sys::Mmap> or L<Mmap> modules, note that the
		1095	scalar must only be modified in-place while an aio operation is pending on
		1096	it).
		1097
		1098	It calls the C<msync> function of your OS, if available, with the memory
		1099	area starting at C<$offset> in the string and ending C<$length> bytes
		1100	later. If C<$length> is negative, counts from the end, and if C<$length>
		1101	is C<undef>, then it goes till the end of the string. The flags can be
		1102	a combination of C<IO::AIO::MS_ASYNC>, C<IO::AIO::MS_INVALIDATE> and
		1103	C<IO::AIO::MS_SYNC>.
		1104
		1105	=item aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
		1106
		1107	This is a rather advanced IO::AIO call, which works best on mmap(2)ed
		1108	scalars.
		1109
		1110	It touches (reads or writes) all memory pages in the specified
		1111	range inside the scalar. All caveats and parameters are the same
		1112	as for C<aio_msync>, above, except for flags, which must be either
		1113	C<0> (which reads all pages and ensures they are instantiated) or
		1114	C<IO::AIO::MT_MODIFY>, which modifies the memory page s(by reading and
		1115	writing an octet from it, which dirties the page).
		1116
		1117	=item aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status)
		1118
		1119	This is a rather advanced IO::AIO call, which works best on mmap(2)ed
		1120	scalars.
		1121
		1122	It reads in all the pages of the underlying storage into memory (if any)
		1123	and locks them, so they are not getting swapped/paged out or removed.
		1124
		1125	If C<$length> is undefined, then the scalar will be locked till the end.
		1126
		1127	On systems that do not implement C<mlock>, this function returns C<-1>
		1128	and sets errno to C<ENOSYS>.
		1129
		1130	Note that the corresponding C<munlock> is synchronous and is
		1131	documented under L<MISCELLANEOUS FUNCTIONS>.
		1132
		1133	Example: open a file, mmap and mlock it - both will be undone when
		1134	C<$data> gets destroyed.
		1135
		1136	open my $fh, "<", $path or die "$path: $!";
		1137	my $data;
		1138	IO::AIO::mmap $data, -s $fh, IO::AIO::PROT_READ, IO::AIO::MAP_SHARED, $fh;
		1139	aio_mlock $data; # mlock in background
		1140
		1141	=item aio_mlockall $flags, $callback->($status)
		1142
		1143	Calls the C<mlockall> function with the given C<$flags> (a combination of
		1144	C<IO::AIO::MCL_CURRENT> and C<IO::AIO::MCL_FUTURE>).
		1145
		1146	On systems that do not implement C<mlockall>, this function returns C<-1>
		1147	and sets errno to C<ENOSYS>.
		1148
		1149	Note that the corresponding C<munlockall> is synchronous and is
		1150	documented under L<MISCELLANEOUS FUNCTIONS>.
		1151
		1152	Example: asynchronously lock all current and future pages into memory.
		1153
		1154	aio_mlockall IO::AIO::MCL_FUTURE;
857		1155
858	=item aio_group $callback->(...)	1156	=item aio_group $callback->(...)
859		1157
860	This is a very special aio request: Instead of doing something, it is a	1158	This is a very special aio request: Instead of doing something, it is a
861	container for other aio requests, which is useful if you want to bundle	1159	container for other aio requests, which is useful if you want to bundle
…		…
911	=item cancel $req	1209	=item cancel $req
912		1210
913	Cancels the request, if possible. Has the effect of skipping execution	1211	Cancels the request, if possible. Has the effect of skipping execution
914	when entering the B<execute> state and skipping calling the callback when	1212	when entering the B<execute> state and skipping calling the callback when
915	entering the the B<result> state, but will leave the request otherwise	1213	entering the the B<result> state, but will leave the request otherwise
916	untouched. That means that requests that currently execute will not be	1214	untouched (with the exception of readdir). That means that requests that
917	stopped and resources held by the request will not be freed prematurely.	1215	currently execute will not be stopped and resources held by the request
		1216	will not be freed prematurely.
918		1217
919	=item cb $req $callback->(...)	1218	=item cb $req $callback->(...)
920		1219
921	Replace (or simply set) the callback registered to the request.	1220	Replace (or simply set) the callback registered to the request.
922		1221
…		…
973	Their lifetime, simplified, looks like this: when they are empty, they	1272	Their lifetime, simplified, looks like this: when they are empty, they
974	will finish very quickly. If they contain only requests that are in the	1273	will finish very quickly. If they contain only requests that are in the
975	C<done> state, they will also finish. Otherwise they will continue to	1274	C<done> state, they will also finish. Otherwise they will continue to
976	exist.	1275	exist.
977		1276
978	That means after creating a group you have some time to add requests. And	1277	That means after creating a group you have some time to add requests
979	in the callbacks of those requests, you can add further requests to the	1278	(precisely before the callback has been invoked, which is only done within
980	group. And only when all those requests have finished will the the group	1279	the C<poll_cb>). And in the callbacks of those requests, you can add
981	itself finish.	1280	further requests to the group. And only when all those requests have
		1281	finished will the the group itself finish.
982		1282
983	=over 4	1283	=over 4
984		1284
985	=item add $grp ...	1285	=item add $grp ...
986		1286
…		…
995	=item $grp->cancel_subs	1295	=item $grp->cancel_subs
996		1296
997	Cancel all subrequests and clears any feeder, but not the group request	1297	Cancel all subrequests and clears any feeder, but not the group request
998	itself. Useful when you queued a lot of events but got a result early.	1298	itself. Useful when you queued a lot of events but got a result early.
999		1299
		1300	The group request will finish normally (you cannot add requests to the
		1301	group).
		1302
1000	=item $grp->result (...)	1303	=item $grp->result (...)
1001		1304
1002	Set the result value(s) that will be passed to the group callback when all	1305	Set the result value(s) that will be passed to the group callback when all
1003	subrequests have finished and set thre groups errno to the current value	1306	subrequests have finished and set the groups errno to the current value
1004	of errno (just like calling C<errno> without an error number). By default,	1307	of errno (just like calling C<errno> without an error number). By default,
1005	no argument will be passed and errno is zero.	1308	no argument will be passed and errno is zero.
1006		1309
1007	=item $grp->errno ([$errno])	1310	=item $grp->errno ([$errno])
1008		1311
…		…
1019	=item feed $grp $callback->($grp)	1322	=item feed $grp $callback->($grp)
1020		1323
1021	Sets a feeder/generator on this group: every group can have an attached	1324	Sets a feeder/generator on this group: every group can have an attached
1022	generator that generates requests if idle. The idea behind this is that,	1325	generator that generates requests if idle. The idea behind this is that,
1023	although you could just queue as many requests as you want in a group,	1326	although you could just queue as many requests as you want in a group,
1024	this might starve other requests for a potentially long time. For	1327	this might starve other requests for a potentially long time. For example,
1025	example, C<aio_scandir> might generate hundreds of thousands C<aio_stat>	1328	C<aio_scandir> might generate hundreds of thousands C<aio_stat> requests,
1026	requests, delaying any later requests for a long time.	1329	delaying any later requests for a long time.
1027		1330
1028	To avoid this, and allow incremental generation of requests, you can	1331	To avoid this, and allow incremental generation of requests, you can
1029	instead a group and set a feeder on it that generates those requests. The	1332	instead a group and set a feeder on it that generates those requests. The
1030	feed callback will be called whenever there are few enough (see C<limit>,	1333	feed callback will be called whenever there are few enough (see C<limit>,
1031	below) requests active in the group itself and is expected to queue more	1334	below) requests active in the group itself and is expected to queue more
…		…
1035	not impose any limits).	1338	not impose any limits).
1036		1339
1037	If the feed does not queue more requests when called, it will be	1340	If the feed does not queue more requests when called, it will be
1038	automatically removed from the group.	1341	automatically removed from the group.
1039		1342
1040	If the feed limit is C<0>, it will be set to C<2> automatically.	1343	If the feed limit is C<0> when this method is called, it will be set to
		1344	C<2> automatically.
1041		1345
1042	Example:	1346	Example:
1043		1347
1044	# stat all files in @files, but only ever use four aio requests concurrently:	1348	# stat all files in @files, but only ever use four aio requests concurrently:
1045		1349
…		…
1057	Sets the feeder limit for the group: The feeder will be called whenever	1361	Sets the feeder limit for the group: The feeder will be called whenever
1058	the group contains less than this many requests.	1362	the group contains less than this many requests.
1059		1363
1060	Setting the limit to C<0> will pause the feeding process.	1364	Setting the limit to C<0> will pause the feeding process.
1061		1365
		1366	The default value for the limit is C<0>, but note that setting a feeder
		1367	automatically bumps it up to C<2>.
		1368
1062	=back	1369	=back
1063		1370
1064	=head2 SUPPORT FUNCTIONS	1371	=head2 SUPPORT FUNCTIONS
1065		1372
1066	=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION	1373	=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION
…		…
1068	=over 4	1375	=over 4
1069		1376
1070	=item $fileno = IO::AIO::poll_fileno	1377	=item $fileno = IO::AIO::poll_fileno
1071		1378
1072	Return the I<request result pipe file descriptor>. This filehandle must be	1379	Return the I<request result pipe file descriptor>. This filehandle must be
1073	polled for reading by some mechanism outside this module (e.g. Event or	1380	polled for reading by some mechanism outside this module (e.g. EV, Glib,
1074	select, see below or the SYNOPSIS). If the pipe becomes readable you have	1381	select and so on, see below or the SYNOPSIS). If the pipe becomes readable
1075	to call C<poll_cb> to check the results.	1382	you have to call C<poll_cb> to check the results.
1076		1383
1077	See C<poll_cb> for an example.	1384	See C<poll_cb> for an example.
1078		1385
1079	=item IO::AIO::poll_cb	1386	=item IO::AIO::poll_cb
1080		1387
1081	Process some outstanding events on the result pipe. You have to call this	1388	Process some outstanding events on the result pipe. You have to call this
1082	regularly. Returns the number of events processed. Returns immediately	1389	regularly. Returns C<0> if all events could be processed, or C<-1> if it
		1390	returned earlier for whatever reason. Returns immediately when no events
1083	when no events are outstanding. The amount of events processed depends on	1391	are outstanding. The amount of events processed depends on the settings of
1084	the settings of C<IO::AIO::max_poll_req> and C<IO::AIO::max_poll_time>.	1392	C<IO::AIO::max_poll_req> and C<IO::AIO::max_poll_time>.
1085		1393
1086	If not all requests were processed for whatever reason, the filehandle	1394	If not all requests were processed for whatever reason, the filehandle
1087	will still be ready when C<poll_cb> returns.	1395	will still be ready when C<poll_cb> returns, so normally you don't have to
		1396	do anything special to have it called later.
1088		1397
1089	Example: Install an Event watcher that automatically calls	1398	Example: Install an Event watcher that automatically calls
1090	IO::AIO::poll_cb with high priority:	1399	IO::AIO::poll_cb with high priority (more examples can be found in the
		1400	SYNOPSIS section, at the top of this document):
1091		1401
1092	Event->io (fd => IO::AIO::poll_fileno,	1402	Event->io (fd => IO::AIO::poll_fileno,
1093	poll => 'r', async => 1,	1403	poll => 'r', async => 1,
1094	cb => \&IO::AIO::poll_cb);	1404	cb => \&IO::AIO::poll_cb);
		1405
		1406	=item IO::AIO::poll_wait
		1407
		1408	If there are any outstanding requests and none of them in the result
		1409	phase, wait till the result filehandle becomes ready for reading (simply
		1410	does a C<select> on the filehandle. This is useful if you want to
		1411	synchronously wait for some requests to finish).
		1412
		1413	See C<nreqs> for an example.
		1414
		1415	=item IO::AIO::poll
		1416
		1417	Waits until some requests have been handled.
		1418
		1419	Returns the number of requests processed, but is otherwise strictly
		1420	equivalent to:
		1421
		1422	IO::AIO::poll_wait, IO::AIO::poll_cb
		1423
		1424	=item IO::AIO::flush
		1425
		1426	Wait till all outstanding AIO requests have been handled.
		1427
		1428	Strictly equivalent to:
		1429
		1430	IO::AIO::poll_wait, IO::AIO::poll_cb
		1431	while IO::AIO::nreqs;
1095		1432
1096	=item IO::AIO::max_poll_reqs $nreqs	1433	=item IO::AIO::max_poll_reqs $nreqs
1097		1434
1098	=item IO::AIO::max_poll_time $seconds	1435	=item IO::AIO::max_poll_time $seconds
1099		1436
…		…
1124	# use a low priority so other tasks have priority	1461	# use a low priority so other tasks have priority
1125	Event->io (fd => IO::AIO::poll_fileno,	1462	Event->io (fd => IO::AIO::poll_fileno,
1126	poll => 'r', nice => 1,	1463	poll => 'r', nice => 1,
1127	cb => &IO::AIO::poll_cb);	1464	cb => &IO::AIO::poll_cb);
1128		1465
1129	=item IO::AIO::poll_wait
1130
1131	If there are any outstanding requests and none of them in the result
1132	phase, wait till the result filehandle becomes ready for reading (simply
1133	does a C<select> on the filehandle. This is useful if you want to
1134	synchronously wait for some requests to finish).
1135
1136	See C<nreqs> for an example.
1137
1138	=item IO::AIO::poll
1139
1140	Waits until some requests have been handled.
1141
1142	Returns the number of requests processed, but is otherwise strictly
1143	equivalent to:
1144
1145	IO::AIO::poll_wait, IO::AIO::poll_cb
1146
1147	=item IO::AIO::flush
1148
1149	Wait till all outstanding AIO requests have been handled.
1150
1151	Strictly equivalent to:
1152
1153	IO::AIO::poll_wait, IO::AIO::poll_cb
1154	while IO::AIO::nreqs;
1155
1156	=back	1466	=back
1157		1467
1158	=head3 CONTROLLING THE NUMBER OF THREADS	1468	=head3 CONTROLLING THE NUMBER OF THREADS
1159		1469
1160	=over	1470	=over
…		…
1206		1516
1207	The default is probably ok in most situations, especially if thread	1517	The default is probably ok in most situations, especially if thread
1208	creation is fast. If thread creation is very slow on your system you might	1518	creation is fast. If thread creation is very slow on your system you might
1209	want to use larger values.	1519	want to use larger values.
1210		1520
1211	=item $oldmaxreqs = IO::AIO::max_outstanding $maxreqs	1521	=item IO::AIO::max_outstanding $maxreqs
1212		1522
1213	This is a very bad function to use in interactive programs because it	1523	This is a very bad function to use in interactive programs because it
1214	blocks, and a bad way to reduce concurrency because it is inexact: Better	1524	blocks, and a bad way to reduce concurrency because it is inexact: Better
1215	use an C<aio_group> together with a feed callback.	1525	use an C<aio_group> together with a feed callback.
1216		1526
…		…
1221		1531
1222	The default value is very large, so there is no practical limit on the	1532	The default value is very large, so there is no practical limit on the
1223	number of outstanding requests.	1533	number of outstanding requests.
1224		1534
1225	You can still queue as many requests as you want. Therefore,	1535	You can still queue as many requests as you want. Therefore,
1226	C<max_oustsanding> is mainly useful in simple scripts (with low values) or	1536	C<max_outstanding> is mainly useful in simple scripts (with low values) or
1227	as a stop gap to shield against fatal memory overflow (with large values).	1537	as a stop gap to shield against fatal memory overflow (with large values).
1228		1538
1229	=back	1539	=back
1230		1540
1231	=head3 STATISTICAL INFORMATION	1541	=head3 STATISTICAL INFORMATION
…		…
1252	Returns the number of requests currently in the pending state (executed,	1562	Returns the number of requests currently in the pending state (executed,
1253	but not yet processed by poll_cb).	1563	but not yet processed by poll_cb).
1254		1564
1255	=back	1565	=back
1256		1566
		1567	=head3 MISCELLANEOUS FUNCTIONS
		1568
		1569	IO::AIO implements some functions that might be useful, but are not
		1570	asynchronous.
		1571
		1572	=over 4
		1573
		1574	=item IO::AIO::sendfile $ofh, $ifh, $offset, $count
		1575
		1576	Calls the C<eio_sendfile_sync> function, which is like C<aio_sendfile>,
		1577	but is blocking (this makes most sense if you know the input data is
		1578	likely cached already and the output filehandle is set to non-blocking
		1579	operations).
		1580
		1581	Returns the number of bytes copied, or C<-1> on error.
		1582
		1583	=item IO::AIO::fadvise $fh, $offset, $len, $advice
		1584
		1585	Simply calls the C<posix_fadvise> function (see it's
		1586	manpage for details). The following advice constants are
		1587	avaiable: C<IO::AIO::FADV_NORMAL>, C<IO::AIO::FADV_SEQUENTIAL>,
		1588	C<IO::AIO::FADV_RANDOM>, C<IO::AIO::FADV_NOREUSE>,
		1589	C<IO::AIO::FADV_WILLNEED>, C<IO::AIO::FADV_DONTNEED>.
		1590
		1591	On systems that do not implement C<posix_fadvise>, this function returns
		1592	ENOSYS, otherwise the return value of C<posix_fadvise>.
		1593
		1594	=item IO::AIO::mmap $scalar, $length, $prot, $flags, $fh[, $offset]
		1595
		1596	Memory-maps a file (or anonymous memory range) and attaches it to the
		1597	given C<$scalar>, which will act like a string scalar.
		1598
		1599	The only operations allowed on the scalar are C<substr>/C<vec> that don't
		1600	change the string length, and most read-only operations such as copying it
		1601	or searching it with regexes and so on.
		1602
		1603	Anything else is unsafe and will, at best, result in memory leaks.
		1604
		1605	The memory map associated with the C<$scalar> is automatically removed
		1606	when the C<$scalar> is destroyed, or when the C<IO::AIO::mmap> or
		1607	C<IO::AIO::munmap> functions are called.
		1608
		1609	This calls the C<mmap>(2) function internally. See your system's manual
		1610	page for details on the C<$length>, C<$prot> and C<$flags> parameters.
		1611
		1612	The C<$length> must be larger than zero and smaller than the actual
		1613	filesize.
		1614
		1615	C<$prot> is a combination of C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_EXEC>,
		1616	C<IO::AIO::PROT_READ> and/or C<IO::AIO::PROT_WRITE>,
		1617
		1618	C<$flags> can be a combination of C<IO::AIO::MAP_SHARED> or
		1619	C<IO::AIO::MAP_PRIVATE>, or a number of system-specific flags (when
		1620	not available, the are defined as 0): C<IO::AIO::MAP_ANONYMOUS>
		1621	(which is set to C<MAP_ANON> if your system only provides this
		1622	constant), C<IO::AIO::MAP_HUGETLB>, C<IO::AIO::MAP_LOCKED>,
		1623	C<IO::AIO::MAP_NORESERVE>, C<IO::AIO::MAP_POPULATE> or
		1624	C<IO::AIO::MAP_NONBLOCK>
		1625
		1626	If C<$fh> is C<undef>, then a file descriptor of C<-1> is passed.
		1627
		1628	C<$offset> is the offset from the start of the file - it generally must be
		1629	a multiple of C<IO::AIO::PAGESIZE> and defaults to C<0>.
		1630
		1631	Example:
		1632
		1633	use Digest::MD5;
		1634	use IO::AIO;
		1635
		1636	open my $fh, "<verybigfile"
		1637	or die "$!";
		1638
		1639	IO::AIO::mmap my $data, -s $fh, IO::AIO::PROT_READ, IO::AIO::MAP_SHARED, $fh
		1640	or die "verybigfile: $!";
		1641
		1642	my $fast_md5 = md5 $data;
		1643
		1644	=item IO::AIO::munmap $scalar
		1645
		1646	Removes a previous mmap and undefines the C<$scalar>.
		1647
		1648	=item IO::AIO::munlock $scalar, $offset = 0, $length = undef
		1649
		1650	Calls the C<munlock> function, undoing the effects of a previous
		1651	C<aio_mlock> call (see its description for details).
		1652
		1653	=item IO::AIO::munlockall
		1654
		1655	Calls the C<munlockall> function.
		1656
		1657	On systems that do not implement C<munlockall>, this function returns
		1658	ENOSYS, otherwise the return value of C<munlockall>.
		1659
		1660	=back
		1661
1257	=cut	1662	=cut
1258		1663
1259	min_parallel 8;	1664	min_parallel 8;
1260		1665
1261	END { flush }	1666	END { flush }
1262		1667
1263	1;	1668	1;
		1669
		1670	=head1 EVENT LOOP INTEGRATION
		1671
		1672	It is recommended to use L<AnyEvent::AIO> to integrate IO::AIO
		1673	automatically into many event loops:
		1674
		1675	# AnyEvent integration (EV, Event, Glib, Tk, POE, urxvt, pureperl...)
		1676	use AnyEvent::AIO;
		1677
		1678	You can also integrate IO::AIO manually into many event loops, here are
		1679	some examples of how to do this:
		1680
		1681	# EV integration
		1682	my $aio_w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb;
		1683
		1684	# Event integration
		1685	Event->io (fd => IO::AIO::poll_fileno,
		1686	poll => 'r',
		1687	cb => \&IO::AIO::poll_cb);
		1688
		1689	# Glib/Gtk2 integration
		1690	add_watch Glib::IO IO::AIO::poll_fileno,
		1691	in => sub { IO::AIO::poll_cb; 1 };
		1692
		1693	# Tk integration
		1694	Tk::Event::IO->fileevent (IO::AIO::poll_fileno, "",
		1695	readable => \&IO::AIO::poll_cb);
		1696
		1697	# Danga::Socket integration
		1698	Danga::Socket->AddOtherFds (IO::AIO::poll_fileno =>
		1699	\&IO::AIO::poll_cb);
1264		1700
1265	=head2 FORK BEHAVIOUR	1701	=head2 FORK BEHAVIOUR
1266		1702
1267	This module should do "the right thing" when the process using it forks:	1703	This module should do "the right thing" when the process using it forks:
1268		1704
…		…
1301		1737
1302	Known bugs will be fixed in the next release.	1738	Known bugs will be fixed in the next release.
1303		1739
1304	=head1 SEE ALSO	1740	=head1 SEE ALSO
1305		1741
1306	L<Coro::AIO>.	1742	L<AnyEvent::AIO> for easy integration into event loops, L<Coro::AIO> for a
		1743	more natural syntax.
1307		1744
1308	=head1 AUTHOR	1745	=head1 AUTHOR
1309		1746
1310	Marc Lehmann <schmorp@schmorp.de>	1747	Marc Lehmann <schmorp@schmorp.de>
1311	http://home.schmorp.de/	1748	http://home.schmorp.de/

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Comparing IO-AIO/AIO.pm (file contents): Revision 1.116 by root, Wed Oct 3 21:27:51 2007 UTC vs. Revision 1.183 by root, Sun Sep 12 03:40:05 2010 UTC

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Comparing IO-AIO/AIO.pm (file contents):
Revision 1.116 by root, Wed Oct 3 21:27:51 2007 UTC vs.
Revision 1.183 by root, Sun Sep 12 03:40:05 2010 UTC