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

Comparing IO-AIO/AIO.pm (file contents):
Revision 1.111 by root, Mon Aug 13 12:08:13 2007 UTC vs.
Revision 1.182 by root, Sun Sep 12 03:36:27 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
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";
…		…
311		369
312		370
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. I<WARNING:> although accepted, you should not pass in a perl	374	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		375
321	This is supposed to be a bug in the API, so that might change. It's	376	Unfortunately, you can't do this to perl. Perl I<insists> very strongly on
322	therefore best to avoid this function.	377	closing the file descriptor associated with the filehandle itself.
323		378
		379	Therefore, C<aio_close> will not close the filehandle - instead it will
		380	use dup2 to overwrite the file descriptor with the write-end of a pipe
		381	(the pipe fd will be created on demand and will be cached).
		382
		383	Or in other words: the file descriptor will be closed, but it will not be
		384	free for reuse until the perl filehandle is closed.
		385
		386	=cut
324		387
325	=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)	388	=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
326		389
327	=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)	390	=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
328		391
329	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<$fh> and
330	into the scalar given by C<$data> and offset C<$dataoffset> and calls the	393	C<$offset> into the scalar given by C<$data> and offset C<$dataoffset>
331	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
332	like the syscall).	395	error, just like the syscall).
333		396
		397	C<aio_read> will, like C<sysread>, shrink or grow the C<$data> scalar to
		398	offset plus the actual number of bytes read.
		399
334	If C<$offset> is undefined, then the current file offset will be used (and	400	If C<$offset> is undefined, then the current file descriptor offset will
335	updated), otherwise the file offset will not be changed by these calls.	401	be used (and updated), otherwise the file descriptor offset will not be
		402	changed by these calls.
336		403
337	If C<$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<$data>.
338		406
339	If C<$dataoffset> is less than zero, it will be counted from the end of	407	If C<$dataoffset> is less than zero, it will be counted from the end of
340	C<$data>.	408	C<$data>.
341		409
342	The C<$data> scalar I<MUST NOT> be modified in any way while the request	410	The C<$data> scalar I<MUST NOT> be modified in any way while the request
…		…
360	than one C<aio_sendfile> per C<$out_fh>, as they will interfere with each	428	than one C<aio_sendfile> per C<$out_fh>, as they will interfere with each
361	other.	429	other.
362		430
363	This call tries to make use of a native C<sendfile> syscall to provide	431	This call tries to make use of a native C<sendfile> syscall to provide
364	zero-copy operation. For this to work, C<$out_fh> should refer to a	432	zero-copy operation. For this to work, C<$out_fh> should refer to a
365	socket, and C<$in_fh> should refer to mmap'able file.	433	socket, and C<$in_fh> should refer to an mmap'able file.
366		434
367	If the native sendfile call fails or is not implemented, it will be	435	If a native sendfile cannot be found or it fails with C<ENOSYS>,
		436	C<ENOTSUP>, C<EOPNOTSUPP>, C<EAFNOSUPPORT>, C<EPROTOTYPE> or C<ENOTSOCK>,
368	emulated, so you can call C<aio_sendfile> on any type of filehandle	437	it will be emulated, so you can call C<aio_sendfile> on any type of
369	regardless of the limitations of the operating system.	438	filehandle regardless of the limitations of the operating system.
370		439
371	Please note, however, that C<aio_sendfile> can read more bytes from	440	Please note, however, that C<aio_sendfile> can read more bytes from
372	C<$in_fh> than are written, and there is no way to find out how many	441	C<$in_fh> than are written, and there is no way to find out how many
373	bytes have been read from C<aio_sendfile> alone, as C<aio_sendfile> only	442	bytes have been read from C<aio_sendfile> alone, as C<aio_sendfile> only
374	provides the number of bytes written to C<$out_fh>. Only if the result	443	provides the number of bytes written to C<$out_fh>. Only if the result
…		…
412	$_[0] and die "stat failed: $!";	481	$_[0] and die "stat failed: $!";
413	print "size is ", -s _, "\n";	482	print "size is ", -s _, "\n";
414	};	483	};
415		484
416		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
417	=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status)	531	=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
418		532
419	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
420	and $mtime being undef). Fractional times are supported if the underlying	534	and $mtime being undef). Fractional times are supported if the underlying
421	syscalls support them.	535	syscalls support them.
…		…
514		628
515	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
516	directory (i.e. opendir + readdir + closedir). The entries will not be	630	directory (i.e. opendir + readdir + closedir). The entries will not be
517	sorted, and will B<NOT> include the C<.> and C<..> entries.	631	sorted, and will B<NOT> include the C<.> and C<..> entries.
518		632
519	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
520	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
521		701
522		702
523	=item aio_load $path, $data, $callback->($status)	703	=item aio_load $path, $data, $callback->($status)
524		704
525	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
526	memory. Status is the same as with aio_read.	706	memory. Status is the same as with aio_read.
527		707
528	=cut	708	=cut
529		709
530	sub aio_load($$;$) {	710	sub aio_load($$;$) {
531	aio_block {
532	my ($path, undef, $cb) = @_;	711	my ($path, undef, $cb) = @_;
533	my $data = \$_[1];	712	my $data = \$_[1];
534		713
535	my $pri = aioreq_pri;	714	my $pri = aioreq_pri;
536	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);
537		721
538	aioreq_pri $pri;	722	aioreq_pri $pri;
539	add $grp aio_open $path, O_RDONLY, 0, sub {
540	my $fh = shift
541	or return $grp->result (-1);
542
543	aioreq_pri $pri;
544	add $grp aio_read $fh, 0, (-s $fh), $$data, 0, sub {	723	add $grp aio_read $fh, 0, (-s $fh), $$data, 0, sub {
545	$grp->result ($_[0]);	724	$grp->result ($_[0]);
546	};
547	};	725	};
548
549	$grp
550	}	726	};
		727
		728	$grp
551	}	729	}
552		730
553	=item aio_copy $srcpath, $dstpath, $callback->($status)	731	=item aio_copy $srcpath, $dstpath, $callback->($status)
554		732
555	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
556	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
557	the C<0> (error) or C<-1> ok.	735	a status of C<0> (ok) or C<-1> (error, see C<$!>).
558		736
559	This is a composite request that it creates the destination file with	737	This is a composite request that creates the destination file with
560	mode 0200 and copies the contents of the source file into it using	738	mode 0200 and copies the contents of the source file into it using
561	C<aio_sendfile>, followed by restoring atime, mtime, access mode and	739	C<aio_sendfile>, followed by restoring atime, mtime, access mode and
562	uid/gid, in that order.	740	uid/gid, in that order.
563		741
564	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
…		…
566	errors are being ignored.	744	errors are being ignored.
567		745
568	=cut	746	=cut
569		747
570	sub aio_copy($$;$) {	748	sub aio_copy($$;$) {
571	aio_block {
572	my ($src, $dst, $cb) = @_;	749	my ($src, $dst, $cb) = @_;
573		750
574	my $pri = aioreq_pri;	751	my $pri = aioreq_pri;
575	my $grp = aio_group $cb;	752	my $grp = aio_group $cb;
576		753
577	aioreq_pri $pri;	754	aioreq_pri $pri;
578	add $grp aio_open $src, O_RDONLY, 0, sub {	755	add $grp aio_open $src, O_RDONLY, 0, sub {
579	if (my $src_fh = $_[0]) {	756	if (my $src_fh = $_[0]) {
580	my @stat = stat $src_fh;	757	my @stat = stat $src_fh; # hmm, might block over nfs?
581		758
582	aioreq_pri $pri;	759	aioreq_pri $pri;
583	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 {
584	if (my $dst_fh = $_[0]) {	761	if (my $dst_fh = $_[0]) {
585	aioreq_pri $pri;	762	aioreq_pri $pri;
586	add $grp aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub {	763	add $grp aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub {
587	if ($_[0] == $stat[7]) {	764	if ($_[0] == $stat[7]) {
588	$grp->result (0);	765	$grp->result (0);
589	close $src_fh;	766	close $src_fh;
590		767
591	# those should not normally block. should. should.
592	utime $stat[8], $stat[9], $dst;
593	chmod $stat[2] & 07777, $dst_fh;
594	chown $stat[4], $stat[5], $dst_fh;
595	close $dst_fh;
596	} else {	768	my $ch = sub {
597	$grp->result (-1);
598	close $src_fh;
599	close $dst_fh;
600
601	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;
602	add $grp aio_unlink $dst;	774	add $grp aio_close $dst_fh;
		775	}
		776	};
603	}	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;
604	};	795	}
605	} else {
606	$grp->result (-1);
607	}	796	};
		797	} else {
		798	$grp->result (-1);
608	},	799	}
609
610	} else {
611	$grp->result (-1);
612	}	800	},
		801
		802	} else {
		803	$grp->result (-1);
613	};	804	}
614
615	$grp
616	}	805	};
		806
		807	$grp
617	}	808	}
618		809
619	=item aio_move $srcpath, $dstpath, $callback->($status)	810	=item aio_move $srcpath, $dstpath, $callback->($status)
620		811
621	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
622	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
623	the C<0> (error) or C<-1> ok.	814	a status of C<0> (ok) or C<-1> (error, see C<$!>).
624		815
625	This is a composite request that tries to rename(2) the file first. If	816	This is a composite request that tries to rename(2) the file first; if
626	rename files with C<EXDEV>, it copies the file with C<aio_copy> and, if	817	rename fails with C<EXDEV>, it copies the file with C<aio_copy> and, if
627	that is successful, unlinking the C<$srcpath>.	818	that is successful, unlinks the C<$srcpath>.
628		819
629	=cut	820	=cut
630		821
631	sub aio_move($$;$) {	822	sub aio_move($$;$) {
632	aio_block {
633	my ($src, $dst, $cb) = @_;	823	my ($src, $dst, $cb) = @_;
634		824
635	my $pri = aioreq_pri;	825	my $pri = aioreq_pri;
636	my $grp = aio_group $cb;	826	my $grp = aio_group $cb;
637		827
638	aioreq_pri $pri;	828	aioreq_pri $pri;
639	add $grp aio_rename $src, $dst, sub {	829	add $grp aio_rename $src, $dst, sub {
640	if ($_[0] && $! == EXDEV) {	830	if ($_[0] && $! == EXDEV) {
641	aioreq_pri $pri;	831	aioreq_pri $pri;
642	add $grp aio_copy $src, $dst, sub {	832	add $grp aio_copy $src, $dst, sub {
643	$grp->result ($_[0]);
644
645	if (!$_[0]) {
646	aioreq_pri $pri;
647	add $grp aio_unlink $src;
648	}
649	};
650	} else {
651	$grp->result ($_[0]);	833	$grp->result ($_[0]);
		834
		835	if (!$_[0]) {
		836	aioreq_pri $pri;
		837	add $grp aio_unlink $src;
		838	}
652	}	839	};
		840	} else {
		841	$grp->result ($_[0]);
653	};	842	}
654
655	$grp
656	}	843	};
		844
		845	$grp
657	}	846	}
658		847
659	=item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs)	848	=item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs)
660		849
661	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
…		…
681		870
682	Implementation notes.	871	Implementation notes.
683		872
684	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.
685		874
		875	If readdir returns file type information, then this is used directly to
		876	find directories.
		877
686	After reading the directory, the modification time, size etc. of the	878	Otherwise, after reading the directory, the modification time, size etc.
687	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
688	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
689	entries are directories (if >= 2). Otherwise, no knowledge of the number	881	how many entries are directories (if >= 2). Otherwise, no knowledge of the
690	of subdirectories will be assumed.	882	number of subdirectories will be assumed.
691		883
692	Then entries will be sorted into likely directories (everything without	884	Then entries will be sorted into likely directories a non-initial dot
693	a non-initial dot currently) and likely non-directories (everything	885	currently) and likely non-directories (see C<aio_readdirx>). Then every
694	else). Then every entry plus an appended C</.> will be C<stat>'ed,	886	entry plus an appended C</.> will be C<stat>'ed, likely directories first,
695	likely directories first. If that succeeds, it assumes that the entry	887	in order of their inode numbers. If that succeeds, it assumes that the
696	is a directory or a symlink to directory (which will be checked	888	entry is a directory or a symlink to directory (which will be checked
697	seperately). This is often faster than stat'ing the entry itself because	889	seperately). This is often faster than stat'ing the entry itself because
698	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
699	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.
700		893
701	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
702	rest of the entries is assumed to be non-directories.	895	rest of the entries is assumed to be non-directories.
703		896
704	This only works with certainty on POSIX (= UNIX) filesystems, which	897	This only works with certainty on POSIX (= UNIX) filesystems, which
…		…
709	directory counting heuristic.	902	directory counting heuristic.
710		903
711	=cut	904	=cut
712		905
713	sub aio_scandir($$;$) {	906	sub aio_scandir($$;$) {
714	aio_block {
715	my ($path, $maxreq, $cb) = @_;	907	my ($path, $maxreq, $cb) = @_;
716		908
717	my $pri = aioreq_pri;	909	my $pri = aioreq_pri;
718		910
719	my $grp = aio_group $cb;	911	my $grp = aio_group $cb;
720		912
721	$maxreq = 4 if $maxreq <= 0;	913	$maxreq = 4 if $maxreq <= 0;
722		914
723	# 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
724	aioreq_pri $pri;	923	aioreq_pri $pri;
725	add $grp aio_stat $path, sub {	924	add $grp aio_readdirx $path, READDIR_DIRS_FIRST, sub {
		925	my $entries = shift
726	return $grp->result () if $_[0];	926	or return $grp->result ();
727	my $now = time;
728	my $hash1 = join ":", (stat _)[0,1,3,7,9];
729		927
730	# read the directory entries	928	# stat the dir another time
731	aioreq_pri $pri;	929	aioreq_pri $pri;
732	add $grp aio_readdir $path, sub {
733	my $entries = shift
734	or return $grp->result ();
735
736	# stat the dir another time
737	aioreq_pri $pri;
738	add $grp aio_stat $path, sub {	930	add $grp aio_stat $path, sub {
739	my $hash2 = join ":", (stat _)[0,1,3,7,9];	931	my $hash2 = join ":", (stat _)[0,1,3,7,9];
740		932
741	my $ndirs;	933	my $ndirs;
742		934
743	# take the slow route if anything looks fishy	935	# take the slow route if anything looks fishy
744	if ($hash1 ne $hash2 or (stat _)[9] == $now) {	936	if ($hash1 ne $hash2 or (stat _)[9] == $now) {
745	$ndirs = -1;	937	$ndirs = -1;
746	} else {	938	} else {
747	# if nlink == 2, we are finished	939	# if nlink == 2, we are finished
748	# on non-posix-fs's, we rely on nlink < 2	940	# for non-posix-fs's, we rely on nlink < 2
749	$ndirs = (stat _)[3] - 2	941	$ndirs = (stat _)[3] - 2
750	or return $grp->result ([], $entries);	942	or return $grp->result ([], $entries);
751	}	943	}
752		944
753	# sort into likely dirs and likely nondirs
754	# dirs == files without ".", short entries first
755	$entries = [map $_->[0],
756	sort { $b->[1] cmp $a->[1] }
757	map [$_, sprintf "%s%04d", (/.\./ ? "1" : "0"), length],
758	@$entries];
759
760	my (@dirs, @nondirs);	945	my (@dirs, @nondirs);
761		946
762	my $statgrp = add $grp aio_group sub {	947	my $statgrp = add $grp aio_group sub {
763	$grp->result (\@dirs, \@nondirs);	948	$grp->result (\@dirs, \@nondirs);
764	};	949	};
765		950
766	limit $statgrp $maxreq;	951	limit $statgrp $maxreq;
767	feed $statgrp sub {	952	feed $statgrp sub {
768	return unless @$entries;	953	return unless @$entries;
769	my $entry = pop @$entries;	954	my $entry = shift @$entries;
770		955
771	aioreq_pri $pri;	956	aioreq_pri $pri;
772	add $statgrp aio_stat "$path/$entry/.", sub {	957	add $statgrp aio_stat "$path/$entry/.", sub {
773	if ($_[0] < 0) {	958	if ($_[0] < 0) {
774	push @nondirs, $entry;	959	push @nondirs, $entry;
775	} else {	960	} else {
776	# need to check for real directory	961	# need to check for real directory
777	aioreq_pri $pri;	962	aioreq_pri $pri;
778	add $statgrp aio_lstat "$path/$entry", sub {	963	add $statgrp aio_lstat "$path/$entry", sub {
779	if (-d _) {	964	if (-d _) {
780	push @dirs, $entry;	965	push @dirs, $entry;
781		966
782	unless (--$ndirs) {	967	unless (--$ndirs) {
783	push @nondirs, @$entries;	968	push @nondirs, @$entries;
784	feed $statgrp;	969	feed $statgrp;
785	}
786	} else {
787	push @nondirs, $entry;
788	}	970	}
		971	} else {
		972	push @nondirs, $entry;
789	}	973	}
790	}	974	}
791	};	975	}
792	};	976	};
793	};	977	};
794	};	978	};
795	};	979	};
796
797	$grp
798	}	980	};
		981
		982	$grp
799	}	983	}
800		984
801	=item aio_rmtree $path, $callback->($status)	985	=item aio_rmtree $path, $callback->($status)
802		986
803	Delete a directory tree starting (and including) C<$path>, return the	987	Delete a directory tree starting (and including) C<$path>, return the
…		…
807		991
808	=cut	992	=cut
809		993
810	sub aio_rmtree;	994	sub aio_rmtree;
811	sub aio_rmtree($;$) {	995	sub aio_rmtree($;$) {
812	aio_block {
813	my ($path, $cb) = @_;	996	my ($path, $cb) = @_;
814		997
815	my $pri = aioreq_pri;	998	my $pri = aioreq_pri;
816	my $grp = aio_group $cb;	999	my $grp = aio_group $cb;
817		1000
818	aioreq_pri $pri;	1001	aioreq_pri $pri;
819	add $grp aio_scandir $path, 0, sub {	1002	add $grp aio_scandir $path, 0, sub {
820	my ($dirs, $nondirs) = @_;	1003	my ($dirs, $nondirs) = @_;
821		1004
822	my $dirgrp = aio_group sub {	1005	my $dirgrp = aio_group sub {
823	add $grp aio_rmdir $path, sub {	1006	add $grp aio_rmdir $path, sub {
824	$grp->result ($_[0]);	1007	$grp->result ($_[0]);
825	};
826	};	1008	};
827
828	(aioreq_pri $pri), add $dirgrp aio_rmtree "$path/$_" for @$dirs;
829	(aioreq_pri $pri), add $dirgrp aio_unlink "$path/$_" for @$nondirs;
830
831	add $grp $dirgrp;
832	};	1009	};
833		1010
834	$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;
835	}	1015	};
		1016
		1017	$grp
836	}	1018	}
		1019
		1020	=item aio_sync $callback->($status)
		1021
		1022	Asynchronously call sync and call the callback when finished.
837		1023
838	=item aio_fsync $fh, $callback->($status)	1024	=item aio_fsync $fh, $callback->($status)
839		1025
840	Asynchronously call fsync on the given filehandle and call the callback	1026	Asynchronously call fsync on the given filehandle and call the callback
841	with the fsync result code.	1027	with the fsync result code.
…		…
845	Asynchronously call fdatasync on the given filehandle and call the	1031	Asynchronously call fdatasync on the given filehandle and call the
846	callback with the fdatasync result code.	1032	callback with the fdatasync result code.
847		1033
848	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
849	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	=item aio_mlockall $flags, $callback->($status)
		1134
		1135	Calls the C<mlockall> function with the given C<$flags> (a combination of
		1136	C<IO::AIO::MCL_CURRENT> and C<IO::AIO::MCL_FUTURE>).
		1137
		1138	On systems that do not implement C<mlockall>, this function returns C<-1>
		1139	and sets errno to C<ENOSYS>.
		1140
		1141	Note that the corresponding C<munlockall> is synchronous and is
		1142	documented under L<MISCELLANEOUS FUNCTIONS>.
850		1143
851	=item aio_group $callback->(...)	1144	=item aio_group $callback->(...)
852		1145
853	This is a very special aio request: Instead of doing something, it is a	1146	This is a very special aio request: Instead of doing something, it is a
854	container for other aio requests, which is useful if you want to bundle	1147	container for other aio requests, which is useful if you want to bundle
…		…
904	=item cancel $req	1197	=item cancel $req
905		1198
906	Cancels the request, if possible. Has the effect of skipping execution	1199	Cancels the request, if possible. Has the effect of skipping execution
907	when entering the B<execute> state and skipping calling the callback when	1200	when entering the B<execute> state and skipping calling the callback when
908	entering the the B<result> state, but will leave the request otherwise	1201	entering the the B<result> state, but will leave the request otherwise
909	untouched. That means that requests that currently execute will not be	1202	untouched (with the exception of readdir). That means that requests that
910	stopped and resources held by the request will not be freed prematurely.	1203	currently execute will not be stopped and resources held by the request
		1204	will not be freed prematurely.
911		1205
912	=item cb $req $callback->(...)	1206	=item cb $req $callback->(...)
913		1207
914	Replace (or simply set) the callback registered to the request.	1208	Replace (or simply set) the callback registered to the request.
915		1209
…		…
966	Their lifetime, simplified, looks like this: when they are empty, they	1260	Their lifetime, simplified, looks like this: when they are empty, they
967	will finish very quickly. If they contain only requests that are in the	1261	will finish very quickly. If they contain only requests that are in the
968	C<done> state, they will also finish. Otherwise they will continue to	1262	C<done> state, they will also finish. Otherwise they will continue to
969	exist.	1263	exist.
970		1264
971	That means after creating a group you have some time to add requests. And	1265	That means after creating a group you have some time to add requests
972	in the callbacks of those requests, you can add further requests to the	1266	(precisely before the callback has been invoked, which is only done within
973	group. And only when all those requests have finished will the the group	1267	the C<poll_cb>). And in the callbacks of those requests, you can add
974	itself finish.	1268	further requests to the group. And only when all those requests have
		1269	finished will the the group itself finish.
975		1270
976	=over 4	1271	=over 4
977		1272
978	=item add $grp ...	1273	=item add $grp ...
979		1274
…		…
988	=item $grp->cancel_subs	1283	=item $grp->cancel_subs
989		1284
990	Cancel all subrequests and clears any feeder, but not the group request	1285	Cancel all subrequests and clears any feeder, but not the group request
991	itself. Useful when you queued a lot of events but got a result early.	1286	itself. Useful when you queued a lot of events but got a result early.
992		1287
		1288	The group request will finish normally (you cannot add requests to the
		1289	group).
		1290
993	=item $grp->result (...)	1291	=item $grp->result (...)
994		1292
995	Set the result value(s) that will be passed to the group callback when all	1293	Set the result value(s) that will be passed to the group callback when all
996	subrequests have finished and set thre groups errno to the current value	1294	subrequests have finished and set the groups errno to the current value
997	of errno (just like calling C<errno> without an error number). By default,	1295	of errno (just like calling C<errno> without an error number). By default,
998	no argument will be passed and errno is zero.	1296	no argument will be passed and errno is zero.
999		1297
1000	=item $grp->errno ([$errno])	1298	=item $grp->errno ([$errno])
1001		1299
…		…
1012	=item feed $grp $callback->($grp)	1310	=item feed $grp $callback->($grp)
1013		1311
1014	Sets a feeder/generator on this group: every group can have an attached	1312	Sets a feeder/generator on this group: every group can have an attached
1015	generator that generates requests if idle. The idea behind this is that,	1313	generator that generates requests if idle. The idea behind this is that,
1016	although you could just queue as many requests as you want in a group,	1314	although you could just queue as many requests as you want in a group,
1017	this might starve other requests for a potentially long time. For	1315	this might starve other requests for a potentially long time. For example,
1018	example, C<aio_scandir> might generate hundreds of thousands C<aio_stat>	1316	C<aio_scandir> might generate hundreds of thousands C<aio_stat> requests,
1019	requests, delaying any later requests for a long time.	1317	delaying any later requests for a long time.
1020		1318
1021	To avoid this, and allow incremental generation of requests, you can	1319	To avoid this, and allow incremental generation of requests, you can
1022	instead a group and set a feeder on it that generates those requests. The	1320	instead a group and set a feeder on it that generates those requests. The
1023	feed callback will be called whenever there are few enough (see C<limit>,	1321	feed callback will be called whenever there are few enough (see C<limit>,
1024	below) requests active in the group itself and is expected to queue more	1322	below) requests active in the group itself and is expected to queue more
…		…
1028	not impose any limits).	1326	not impose any limits).
1029		1327
1030	If the feed does not queue more requests when called, it will be	1328	If the feed does not queue more requests when called, it will be
1031	automatically removed from the group.	1329	automatically removed from the group.
1032		1330
1033	If the feed limit is C<0>, it will be set to C<2> automatically.	1331	If the feed limit is C<0> when this method is called, it will be set to
		1332	C<2> automatically.
1034		1333
1035	Example:	1334	Example:
1036		1335
1037	# stat all files in @files, but only ever use four aio requests concurrently:	1336	# stat all files in @files, but only ever use four aio requests concurrently:
1038		1337
…		…
1050	Sets the feeder limit for the group: The feeder will be called whenever	1349	Sets the feeder limit for the group: The feeder will be called whenever
1051	the group contains less than this many requests.	1350	the group contains less than this many requests.
1052		1351
1053	Setting the limit to C<0> will pause the feeding process.	1352	Setting the limit to C<0> will pause the feeding process.
1054		1353
		1354	The default value for the limit is C<0>, but note that setting a feeder
		1355	automatically bumps it up to C<2>.
		1356
1055	=back	1357	=back
1056		1358
1057	=head2 SUPPORT FUNCTIONS	1359	=head2 SUPPORT FUNCTIONS
1058		1360
1059	=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION	1361	=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION
…		…
1061	=over 4	1363	=over 4
1062		1364
1063	=item $fileno = IO::AIO::poll_fileno	1365	=item $fileno = IO::AIO::poll_fileno
1064		1366
1065	Return the I<request result pipe file descriptor>. This filehandle must be	1367	Return the I<request result pipe file descriptor>. This filehandle must be
1066	polled for reading by some mechanism outside this module (e.g. Event or	1368	polled for reading by some mechanism outside this module (e.g. EV, Glib,
1067	select, see below or the SYNOPSIS). If the pipe becomes readable you have	1369	select and so on, see below or the SYNOPSIS). If the pipe becomes readable
1068	to call C<poll_cb> to check the results.	1370	you have to call C<poll_cb> to check the results.
1069		1371
1070	See C<poll_cb> for an example.	1372	See C<poll_cb> for an example.
1071		1373
1072	=item IO::AIO::poll_cb	1374	=item IO::AIO::poll_cb
1073		1375
1074	Process some outstanding events on the result pipe. You have to call this	1376	Process some outstanding events on the result pipe. You have to call this
1075	regularly. Returns the number of events processed. Returns immediately	1377	regularly. Returns C<0> if all events could be processed, or C<-1> if it
		1378	returned earlier for whatever reason. Returns immediately when no events
1076	when no events are outstanding. The amount of events processed depends on	1379	are outstanding. The amount of events processed depends on the settings of
1077	the settings of C<IO::AIO::max_poll_req> and C<IO::AIO::max_poll_time>.	1380	C<IO::AIO::max_poll_req> and C<IO::AIO::max_poll_time>.
1078		1381
1079	If not all requests were processed for whatever reason, the filehandle	1382	If not all requests were processed for whatever reason, the filehandle
1080	will still be ready when C<poll_cb> returns.	1383	will still be ready when C<poll_cb> returns, so normally you don't have to
		1384	do anything special to have it called later.
1081		1385
1082	Example: Install an Event watcher that automatically calls	1386	Example: Install an Event watcher that automatically calls
1083	IO::AIO::poll_cb with high priority:	1387	IO::AIO::poll_cb with high priority (more examples can be found in the
		1388	SYNOPSIS section, at the top of this document):
1084		1389
1085	Event->io (fd => IO::AIO::poll_fileno,	1390	Event->io (fd => IO::AIO::poll_fileno,
1086	poll => 'r', async => 1,	1391	poll => 'r', async => 1,
1087	cb => \&IO::AIO::poll_cb);	1392	cb => \&IO::AIO::poll_cb);
		1393
		1394	=item IO::AIO::poll_wait
		1395
		1396	If there are any outstanding requests and none of them in the result
		1397	phase, wait till the result filehandle becomes ready for reading (simply
		1398	does a C<select> on the filehandle. This is useful if you want to
		1399	synchronously wait for some requests to finish).
		1400
		1401	See C<nreqs> for an example.
		1402
		1403	=item IO::AIO::poll
		1404
		1405	Waits until some requests have been handled.
		1406
		1407	Returns the number of requests processed, but is otherwise strictly
		1408	equivalent to:
		1409
		1410	IO::AIO::poll_wait, IO::AIO::poll_cb
		1411
		1412	=item IO::AIO::flush
		1413
		1414	Wait till all outstanding AIO requests have been handled.
		1415
		1416	Strictly equivalent to:
		1417
		1418	IO::AIO::poll_wait, IO::AIO::poll_cb
		1419	while IO::AIO::nreqs;
1088		1420
1089	=item IO::AIO::max_poll_reqs $nreqs	1421	=item IO::AIO::max_poll_reqs $nreqs
1090		1422
1091	=item IO::AIO::max_poll_time $seconds	1423	=item IO::AIO::max_poll_time $seconds
1092		1424
…		…
1117	# use a low priority so other tasks have priority	1449	# use a low priority so other tasks have priority
1118	Event->io (fd => IO::AIO::poll_fileno,	1450	Event->io (fd => IO::AIO::poll_fileno,
1119	poll => 'r', nice => 1,	1451	poll => 'r', nice => 1,
1120	cb => &IO::AIO::poll_cb);	1452	cb => &IO::AIO::poll_cb);
1121		1453
1122	=item IO::AIO::poll_wait
1123
1124	If there are any outstanding requests and none of them in the result
1125	phase, wait till the result filehandle becomes ready for reading (simply
1126	does a C<select> on the filehandle. This is useful if you want to
1127	synchronously wait for some requests to finish).
1128
1129	See C<nreqs> for an example.
1130
1131	=item IO::AIO::poll
1132
1133	Waits until some requests have been handled.
1134
1135	Returns the number of requests processed, but is otherwise strictly
1136	equivalent to:
1137
1138	IO::AIO::poll_wait, IO::AIO::poll_cb
1139
1140	=item IO::AIO::flush
1141
1142	Wait till all outstanding AIO requests have been handled.
1143
1144	Strictly equivalent to:
1145
1146	IO::AIO::poll_wait, IO::AIO::poll_cb
1147	while IO::AIO::nreqs;
1148
1149	=back	1454	=back
1150		1455
1151	=head3 CONTROLLING THE NUMBER OF THREADS	1456	=head3 CONTROLLING THE NUMBER OF THREADS
1152		1457
1153	=over	1458	=over
…		…
1199		1504
1200	The default is probably ok in most situations, especially if thread	1505	The default is probably ok in most situations, especially if thread
1201	creation is fast. If thread creation is very slow on your system you might	1506	creation is fast. If thread creation is very slow on your system you might
1202	want to use larger values.	1507	want to use larger values.
1203		1508
1204	=item $oldmaxreqs = IO::AIO::max_outstanding $maxreqs	1509	=item IO::AIO::max_outstanding $maxreqs
1205		1510
1206	This is a very bad function to use in interactive programs because it	1511	This is a very bad function to use in interactive programs because it
1207	blocks, and a bad way to reduce concurrency because it is inexact: Better	1512	blocks, and a bad way to reduce concurrency because it is inexact: Better
1208	use an C<aio_group> together with a feed callback.	1513	use an C<aio_group> together with a feed callback.
1209		1514
1210	Sets the maximum number of outstanding requests to C<$nreqs>. If you	1515	Sets the maximum number of outstanding requests to C<$nreqs>. If you
1211	to queue up more than this number of requests, the next call to the	1516	do queue up more than this number of requests, the next call to the
1212	C<poll_cb> (and C<poll_some> and other functions calling C<poll_cb>)	1517	C<poll_cb> (and C<poll_some> and other functions calling C<poll_cb>)
1213	function will block until the limit is no longer exceeded.	1518	function will block until the limit is no longer exceeded.
1214		1519
1215	The default value is very large, so there is no practical limit on the	1520	The default value is very large, so there is no practical limit on the
1216	number of outstanding requests.	1521	number of outstanding requests.
1217		1522
1218	You can still queue as many requests as you want. Therefore,	1523	You can still queue as many requests as you want. Therefore,
1219	C<max_oustsanding> is mainly useful in simple scripts (with low values) or	1524	C<max_outstanding> is mainly useful in simple scripts (with low values) or
1220	as a stop gap to shield against fatal memory overflow (with large values).	1525	as a stop gap to shield against fatal memory overflow (with large values).
1221		1526
1222	=back	1527	=back
1223		1528
1224	=head3 STATISTICAL INFORMATION	1529	=head3 STATISTICAL INFORMATION
…		…
1245	Returns the number of requests currently in the pending state (executed,	1550	Returns the number of requests currently in the pending state (executed,
1246	but not yet processed by poll_cb).	1551	but not yet processed by poll_cb).
1247		1552
1248	=back	1553	=back
1249		1554
		1555	=head3 MISCELLANEOUS FUNCTIONS
		1556
		1557	IO::AIO implements some functions that might be useful, but are not
		1558	asynchronous.
		1559
		1560	=over 4
		1561
		1562	=item IO::AIO::sendfile $ofh, $ifh, $offset, $count
		1563
		1564	Calls the C<eio_sendfile_sync> function, which is like C<aio_sendfile>,
		1565	but is blocking (this makes most sense if you know the input data is
		1566	likely cached already and the output filehandle is set to non-blocking
		1567	operations).
		1568
		1569	Returns the number of bytes copied, or C<-1> on error.
		1570
		1571	=item IO::AIO::fadvise $fh, $offset, $len, $advice
		1572
		1573	Simply calls the C<posix_fadvise> function (see it's
		1574	manpage for details). The following advice constants are
		1575	avaiable: C<IO::AIO::FADV_NORMAL>, C<IO::AIO::FADV_SEQUENTIAL>,
		1576	C<IO::AIO::FADV_RANDOM>, C<IO::AIO::FADV_NOREUSE>,
		1577	C<IO::AIO::FADV_WILLNEED>, C<IO::AIO::FADV_DONTNEED>.
		1578
		1579	On systems that do not implement C<posix_fadvise>, this function returns
		1580	ENOSYS, otherwise the return value of C<posix_fadvise>.
		1581
		1582	=item IO::AIO::mmap $scalar, $length, $prot, $flags, $fh[, $offset]
		1583
		1584	Memory-maps a file (or anonymous memory range) and attaches it to the
		1585	given C<$scalar>, which will act like a string scalar.
		1586
		1587	The only operations allowed on the scalar are C<substr>/C<vec> that don't
		1588	change the string length, and most read-only operations such as copying it
		1589	or searching it with regexes and so on.
		1590
		1591	Anything else is unsafe and will, at best, result in memory leaks.
		1592
		1593	The memory map associated with the C<$scalar> is automatically removed
		1594	when the C<$scalar> is destroyed, or when the C<IO::AIO::mmap> or
		1595	C<IO::AIO::munmap> functions are called.
		1596
		1597	This calls the C<mmap>(2) function internally. See your system's manual
		1598	page for details on the C<$length>, C<$prot> and C<$flags> parameters.
		1599
		1600	The C<$length> must be larger than zero and smaller than the actual
		1601	filesize.
		1602
		1603	C<$prot> is a combination of C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_EXEC>,
		1604	C<IO::AIO::PROT_READ> and/or C<IO::AIO::PROT_WRITE>,
		1605
		1606	C<$flags> can be a combination of C<IO::AIO::MAP_SHARED> or
		1607	C<IO::AIO::MAP_PRIVATE>, or a number of system-specific flags (when
		1608	not available, the are defined as 0): C<IO::AIO::MAP_ANONYMOUS>
		1609	(which is set to C<MAP_ANON> if your system only provides this
		1610	constant), C<IO::AIO::MAP_HUGETLB>, C<IO::AIO::MAP_LOCKED>,
		1611	C<IO::AIO::MAP_NORESERVE>, C<IO::AIO::MAP_POPULATE> or
		1612	C<IO::AIO::MAP_NONBLOCK>
		1613
		1614	If C<$fh> is C<undef>, then a file descriptor of C<-1> is passed.
		1615
		1616	C<$offset> is the offset from the start of the file - it generally must be
		1617	a multiple of C<IO::AIO::PAGESIZE> and defaults to C<0>.
		1618
		1619	Example:
		1620
		1621	use Digest::MD5;
		1622	use IO::AIO;
		1623
		1624	open my $fh, "<verybigfile"
		1625	or die "$!";
		1626
		1627	IO::AIO::mmap my $data, -s $fh, IO::AIO::PROT_READ, IO::AIO::MAP_SHARED, $fh
		1628	or die "verybigfile: $!";
		1629
		1630	my $fast_md5 = md5 $data;
		1631
		1632	=item IO::AIO::munmap $scalar
		1633
		1634	Removes a previous mmap and undefines the C<$scalar>.
		1635
		1636	=item IO::AIO::munlock $scalar, $offset = 0, $length = undef
		1637
		1638	Calls the C<munlock> function, undoing the effects of a previous
		1639	C<aio_mlock> call (see its description for details).
		1640
		1641	=item IO::AIO::munlockall
		1642
		1643	Calls the C<munlockall> function.
		1644
		1645	On systems that do not implement C<munlockall>, this function returns
		1646	ENOSYS, otherwise the return value of C<munlockall>.
		1647
		1648	=back
		1649
1250	=cut	1650	=cut
1251		1651
1252	# support function to convert a fd into a perl filehandle
1253	sub _fd2fh {
1254	return undef if $_[0] < 0;
1255
1256	# try to generate nice filehandles
1257	my $sym = "IO::AIO::fd#$_[0]";
1258	local *$sym;
1259
1260	open *$sym, "+<&=$_[0]" # usually works under any unix
1261	or open *$sym, "<&=$_[0]" # cygwin needs this
1262	or open *$sym, ">&=$_[0]" # or this
1263	or return undef;
1264
1265	*$sym
1266	}
1267
1268	min_parallel 8;	1652	min_parallel 8;
1269		1653
1270	END { flush }	1654	END { flush }
1271		1655
1272	1;	1656	1;
		1657
		1658	=head1 EVENT LOOP INTEGRATION
		1659
		1660	It is recommended to use L<AnyEvent::AIO> to integrate IO::AIO
		1661	automatically into many event loops:
		1662
		1663	# AnyEvent integration (EV, Event, Glib, Tk, POE, urxvt, pureperl...)
		1664	use AnyEvent::AIO;
		1665
		1666	You can also integrate IO::AIO manually into many event loops, here are
		1667	some examples of how to do this:
		1668
		1669	# EV integration
		1670	my $aio_w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb;
		1671
		1672	# Event integration
		1673	Event->io (fd => IO::AIO::poll_fileno,
		1674	poll => 'r',
		1675	cb => \&IO::AIO::poll_cb);
		1676
		1677	# Glib/Gtk2 integration
		1678	add_watch Glib::IO IO::AIO::poll_fileno,
		1679	in => sub { IO::AIO::poll_cb; 1 };
		1680
		1681	# Tk integration
		1682	Tk::Event::IO->fileevent (IO::AIO::poll_fileno, "",
		1683	readable => \&IO::AIO::poll_cb);
		1684
		1685	# Danga::Socket integration
		1686	Danga::Socket->AddOtherFds (IO::AIO::poll_fileno =>
		1687	\&IO::AIO::poll_cb);
1273		1688
1274	=head2 FORK BEHAVIOUR	1689	=head2 FORK BEHAVIOUR
1275		1690
1276	This module should do "the right thing" when the process using it forks:	1691	This module should do "the right thing" when the process using it forks:
1277		1692
…		…
1310		1725
1311	Known bugs will be fixed in the next release.	1726	Known bugs will be fixed in the next release.
1312		1727
1313	=head1 SEE ALSO	1728	=head1 SEE ALSO
1314		1729
1315	L<Coro::AIO>.	1730	L<AnyEvent::AIO> for easy integration into event loops, L<Coro::AIO> for a
		1731	more natural syntax.
1316		1732
1317	=head1 AUTHOR	1733	=head1 AUTHOR
1318		1734
1319	Marc Lehmann <schmorp@schmorp.de>	1735	Marc Lehmann <schmorp@schmorp.de>
1320	http://home.schmorp.de/	1736	http://home.schmorp.de/

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Comparing IO-AIO/AIO.pm (file contents): Revision 1.111 by root, Mon Aug 13 12:08:13 2007 UTC vs. Revision 1.182 by root, Sun Sep 12 03:36:27 2010 UTC

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Comparing IO-AIO/AIO.pm (file contents):
Revision 1.111 by root, Mon Aug 13 12:08:13 2007 UTC vs.
Revision 1.182 by root, Sun Sep 12 03:36:27 2010 UTC