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

Comparing IO-AIO/AIO.pm (file contents):
Revision 1.113 by root, Thu Sep 20 14:06:21 2007 UTC vs.
Revision 1.185 by root, Sat Dec 11 19:06:07 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 = '3.7';
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::madvise $scalar, $offset, $length, $advice
		271	IO::AIO::mprotect $scalar, $offset, $length, $protect
		272	IO::AIO::munlock $scalar, $offset = 0, $length = undef
		273	IO::AIO::munlockall
214		274
215	=head2 AIO REQUEST FUNCTIONS	275	=head2 AIO REQUEST FUNCTIONS
216		276
217	All the C<aio_*> calls are more or less thin wrappers around the syscall	277	All the C<aio_*> calls are more or less thin wrappers around the syscall
218	with the same name (sans C<aio_>). The arguments are similar or identical,	278	with the same name (sans C<aio_>). The arguments are similar or identical,
219	and they all accept an additional (and optional) C<$callback> argument	279	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	280	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	281	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	282	perl, which usually delivers "false") as its sole argument after the given
223	syscall has been executed asynchronously.	283	syscall has been executed asynchronously.
224		284
225	All functions expecting a filehandle keep a copy of the filehandle	285	All functions expecting a filehandle keep a copy of the filehandle
226	internally until the request has finished.	286	internally until the request has finished.
227		287
…		…
241	your pathnames to the locale (or other) encoding in effect in the user	301	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)	302	environment, d) use Glib::filename_from_unicode on unicode filenames or e)
243	use something else to ensure your scalar has the correct contents.	303	use something else to ensure your scalar has the correct contents.
244		304
245	This works, btw. independent of the internal UTF-8 bit, which IO::AIO	305	This works, btw. independent of the internal UTF-8 bit, which IO::AIO
246	handles correctly wether it is set or not.	306	handles correctly whether it is set or not.
247		307
248	=over 4	308	=over 4
249		309
250	=item $prev_pri = aioreq_pri [$pri]	310	=item $prev_pri = aioreq_pri [$pri]
251		311
…		…
298	by the umask in effect then the request is being executed, so better never	358	by the umask in effect then the request is being executed, so better never
299	change the umask.	359	change the umask.
300		360
301	Example:	361	Example:
302		362
303	aio_open "/etc/passwd", O_RDONLY, 0, sub {	363	aio_open "/etc/passwd", IO::AIO::O_RDONLY, 0, sub {
304	if ($_[0]) {	364	if ($_[0]) {
305	print "open successful, fh is $_[0]\n";	365	print "open successful, fh is $_[0]\n";
306	...	366	...
307	} else {	367	} else {
308	die "open failed: $!\n";	368	die "open failed: $!\n";
…		…
311		371
312		372
313	=item aio_close $fh, $callback->($status)	373	=item aio_close $fh, $callback->($status)
314		374
315	Asynchronously close a file and call the callback with the result	375	Asynchronously close a file and call the callback with the result
316	code. I<WARNING:> although accepted, you should not pass in a perl	376	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		377
321	This is supposed to be a bug in the API, so that might change. It's	378	Unfortunately, you can't do this to perl. Perl I<insists> very strongly on
322	therefore best to avoid this function.	379	closing the file descriptor associated with the filehandle itself.
323		380
		381	Therefore, C<aio_close> will not close the filehandle - instead it will
		382	use dup2 to overwrite the file descriptor with the write-end of a pipe
		383	(the pipe fd will be created on demand and will be cached).
		384
		385	Or in other words: the file descriptor will be closed, but it will not be
		386	free for reuse until the perl filehandle is closed.
		387
		388	=cut
324		389
325	=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)	390	=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
326		391
327	=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)	392	=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
328		393
329	Reads or writes C<$length> bytes from the specified C<$fh> and C<$offset>	394	Reads or writes C<$length> bytes from or to the specified C<$fh> and
330	into the scalar given by C<$data> and offset C<$dataoffset> and calls the	395	C<$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	396	and calls the callback without the actual number of bytes read (or -1 on
332	like the syscall).	397	error, just like the syscall).
		398
		399	C<aio_read> will, like C<sysread>, shrink or grow the C<$data> scalar to
		400	offset plus the actual number of bytes read.
333		401
334	If C<$offset> is undefined, then the current file descriptor offset will	402	If C<$offset> is undefined, then the current file descriptor offset will
335	be used (and updated), otherwise the file descriptor offset will not be	403	be used (and updated), otherwise the file descriptor offset will not be
336	changed by these calls.	404	changed by these calls.
337		405
338	If C<$length> is undefined in C<aio_write>, use the remaining length of C<$data>.	406	If C<$length> is undefined in C<aio_write>, use the remaining length of
		407	C<$data>.
339		408
340	If C<$dataoffset> is less than zero, it will be counted from the end of	409	If C<$dataoffset> is less than zero, it will be counted from the end of
341	C<$data>.	410	C<$data>.
342		411
343	The C<$data> scalar I<MUST NOT> be modified in any way while the request	412	The C<$data> scalar I<MUST NOT> be modified in any way while the request
…		…
359	reading at byte offset C<$in_offset>, and starts writing at the current	428	reading at byte offset C<$in_offset>, and starts writing at the current
360	file offset of C<$out_fh>. Because of that, it is not safe to issue more	429	file offset of C<$out_fh>. Because of that, it is not safe to issue more
361	than one C<aio_sendfile> per C<$out_fh>, as they will interfere with each	430	than one C<aio_sendfile> per C<$out_fh>, as they will interfere with each
362	other.	431	other.
363		432
		433	Please note that C<aio_sendfile> can read more bytes from C<$in_fh> than
		434	are written, and there is no way to find out how many bytes have been read
		435	from C<aio_sendfile> alone, as C<aio_sendfile> only provides the number of
		436	bytes written to C<$out_fh>. Only if the result value equals C<$length>
		437	one can assume that C<$length> bytes have been read.
		438
		439	Unlike with other C<aio_> functions, it makes a lot of sense to use
		440	C<aio_sendfile> on non-blocking sockets, as long as one end (typically
		441	the C<$in_fh>) is a file - the file I/O will then be asynchronous, while
		442	the socket I/O will be non-blocking. Note, however, that you can run into
		443	a trap where C<aio_sendfile> reads some data with readahead, then fails
		444	to write all data, and when the socket is ready the next time, the data
		445	in the cache is already lost, forcing C<aio_sendfile> to again hit the
		446	disk. Explicit C<aio_read> + C<aio_write> let's you control resource usage
		447	much better.
		448
364	This call tries to make use of a native C<sendfile> syscall to provide	449	This call tries to make use of a native C<sendfile> syscall to provide
365	zero-copy operation. For this to work, C<$out_fh> should refer to a	450	zero-copy operation. For this to work, C<$out_fh> should refer to a
366	socket, and C<$in_fh> should refer to mmap'able file.	451	socket, and C<$in_fh> should refer to an mmap'able file.
367		452
368	If the native sendfile call fails or is not implemented, it will be	453	If a native sendfile cannot be found or it fails with C<ENOSYS>,
		454	C<ENOTSUP>, C<EOPNOTSUPP>, C<EAFNOSUPPORT>, C<EPROTOTYPE> or C<ENOTSOCK>,
369	emulated, so you can call C<aio_sendfile> on any type of filehandle	455	it will be emulated, so you can call C<aio_sendfile> on any type of
370	regardless of the limitations of the operating system.	456	filehandle regardless of the limitations of the operating system.
371
372	Please note, however, that C<aio_sendfile> can read more bytes from
373	C<$in_fh> than are written, and there is no way to find out how many
374	bytes have been read from C<aio_sendfile> alone, as C<aio_sendfile> only
375	provides the number of bytes written to C<$out_fh>. Only if the result
376	value equals C<$length> one can assume that C<$length> bytes have been
377	read.
378		457
379		458
380	=item aio_readahead $fh,$offset,$length, $callback->($retval)	459	=item aio_readahead $fh,$offset,$length, $callback->($retval)
381		460
382	C<aio_readahead> populates the page cache with data from a file so that	461	C<aio_readahead> populates the page cache with data from a file so that
…		…
413	$_[0] and die "stat failed: $!";	492	$_[0] and die "stat failed: $!";
414	print "size is ", -s _, "\n";	493	print "size is ", -s _, "\n";
415	};	494	};
416		495
417		496
		497	=item aio_statvfs $fh_or_path, $callback->($statvfs)
		498
		499	Works like the POSIX C<statvfs> or C<fstatvfs> syscalls, depending on
		500	whether a file handle or path was passed.
		501
		502	On success, the callback is passed a hash reference with the following
		503	members: C<bsize>, C<frsize>, C<blocks>, C<bfree>, C<bavail>, C<files>,
		504	C<ffree>, C<favail>, C<fsid>, C<flag> and C<namemax>. On failure, C<undef>
		505	is passed.
		506
		507	The following POSIX IO::AIO::ST_* constants are defined: C<ST_RDONLY> and
		508	C<ST_NOSUID>.
		509
		510	The following non-POSIX IO::AIO::ST_* flag masks are defined to
		511	their correct value when available, or to C<0> on systems that do
		512	not support them: C<ST_NODEV>, C<ST_NOEXEC>, C<ST_SYNCHRONOUS>,
		513	C<ST_MANDLOCK>, C<ST_WRITE>, C<ST_APPEND>, C<ST_IMMUTABLE>, C<ST_NOATIME>,
		514	C<ST_NODIRATIME> and C<ST_RELATIME>.
		515
		516	Example: stat C</wd> and dump out the data if successful.
		517
		518	aio_statvfs "/wd", sub {
		519	my $f = $_[0]
		520	or die "statvfs: $!";
		521
		522	use Data::Dumper;
		523	say Dumper $f;
		524	};
		525
		526	# result:
		527	{
		528	bsize => 1024,
		529	bfree => 4333064312,
		530	blocks => 10253828096,
		531	files => 2050765568,
		532	flag => 4096,
		533	favail => 2042092649,
		534	bavail => 4333064312,
		535	ffree => 2042092649,
		536	namemax => 255,
		537	frsize => 1024,
		538	fsid => 1810
		539	}
		540
		541
418	=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status)	542	=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
419		543
420	Works like perl's C<utime> function (including the special case of $atime	544	Works like perl's C<utime> function (including the special case of $atime
421	and $mtime being undef). Fractional times are supported if the underlying	545	and $mtime being undef). Fractional times are supported if the underlying
422	syscalls support them.	546	syscalls support them.
…		…
515		639
516	Unlike the POSIX call of the same name, C<aio_readdir> reads an entire	640	Unlike the POSIX call of the same name, C<aio_readdir> reads an entire
517	directory (i.e. opendir + readdir + closedir). The entries will not be	641	directory (i.e. opendir + readdir + closedir). The entries will not be
518	sorted, and will B<NOT> include the C<.> and C<..> entries.	642	sorted, and will B<NOT> include the C<.> and C<..> entries.
519		643
520	The callback a single argument which is either C<undef> or an array-ref	644	The callback is passed a single argument which is either C<undef> or an
521	with the filenames.	645	array-ref with the filenames.
		646
		647
		648	=item aio_readdirx $pathname, $flags, $callback->($entries, $flags)
		649
		650	Quite similar to C<aio_readdir>, but the C<$flags> argument allows to tune
		651	behaviour and output format. In case of an error, C<$entries> will be
		652	C<undef>.
		653
		654	The flags are a combination of the following constants, ORed together (the
		655	flags will also be passed to the callback, possibly modified):
		656
		657	=over 4
		658
		659	=item IO::AIO::READDIR_DENTS
		660
		661	When this flag is off, then the callback gets an arrayref with of names
		662	only (as with C<aio_readdir>), otherwise it gets an arrayref with
		663	C<[$name, $type, $inode]> arrayrefs, each describing a single directory
		664	entry in more detail.
		665
		666	C<$name> is the name of the entry.
		667
		668	C<$type> is one of the C<IO::AIO::DT_xxx> constants:
		669
		670	C<IO::AIO::DT_UNKNOWN>, C<IO::AIO::DT_FIFO>, C<IO::AIO::DT_CHR>, C<IO::AIO::DT_DIR>,
		671	C<IO::AIO::DT_BLK>, C<IO::AIO::DT_REG>, C<IO::AIO::DT_LNK>, C<IO::AIO::DT_SOCK>,
		672	C<IO::AIO::DT_WHT>.
		673
		674	C<IO::AIO::DT_UNKNOWN> means just that: readdir does not know. If you need to
		675	know, you have to run stat yourself. Also, for speed reasons, the C<$type>
		676	scalars are read-only: you can not modify them.
		677
		678	C<$inode> is the inode number (which might not be exact on systems with 64
		679	bit inode numbers and 32 bit perls). This field has unspecified content on
		680	systems that do not deliver the inode information.
		681
		682	=item IO::AIO::READDIR_DIRS_FIRST
		683
		684	When this flag is set, then the names will be returned in an order where
		685	likely directories come first. This is useful when you need to quickly
		686	find directories, or you want to find all directories while avoiding to
		687	stat() each entry.
		688
		689	If the system returns type information in readdir, then this is used
		690	to find directories directly. Otherwise, likely directories are files
		691	beginning with ".", or otherwise files with no dots, of which files with
		692	short names are tried first.
		693
		694	=item IO::AIO::READDIR_STAT_ORDER
		695
		696	When this flag is set, then the names will be returned in an order
		697	suitable for stat()'ing each one. That is, when you plan to stat()
		698	all files in the given directory, then the returned order will likely
		699	be fastest.
		700
		701	If both this flag and C<IO::AIO::READDIR_DIRS_FIRST> are specified, then
		702	the likely dirs come first, resulting in a less optimal stat order.
		703
		704	=item IO::AIO::READDIR_FOUND_UNKNOWN
		705
		706	This flag should not be set when calling C<aio_readdirx>. Instead, it
		707	is being set by C<aio_readdirx>, when any of the C<$type>'s found were
		708	C<IO::AIO::DT_UNKNOWN>. The absense of this flag therefore indicates that all
		709	C<$type>'s are known, which can be used to speed up some algorithms.
		710
		711	=back
522		712
523		713
524	=item aio_load $path, $data, $callback->($status)	714	=item aio_load $path, $data, $callback->($status)
525		715
526	This is a composite request that tries to fully load the given file into	716	This is a composite request that tries to fully load the given file into
527	memory. Status is the same as with aio_read.	717	memory. Status is the same as with aio_read.
528		718
529	=cut	719	=cut
530		720
531	sub aio_load($$;$) {	721	sub aio_load($$;$) {
532	aio_block {
533	my ($path, undef, $cb) = @_;	722	my ($path, undef, $cb) = @_;
534	my $data = \$_[1];	723	my $data = \$_[1];
535		724
536	my $pri = aioreq_pri;	725	my $pri = aioreq_pri;
537	my $grp = aio_group $cb;	726	my $grp = aio_group $cb;
		727
		728	aioreq_pri $pri;
		729	add $grp aio_open $path, O_RDONLY, 0, sub {
		730	my $fh = shift
		731	or return $grp->result (-1);
538		732
539	aioreq_pri $pri;	733	aioreq_pri $pri;
540	add $grp aio_open $path, O_RDONLY, 0, sub {
541	my $fh = shift
542	or return $grp->result (-1);
543
544	aioreq_pri $pri;
545	add $grp aio_read $fh, 0, (-s $fh), $$data, 0, sub {	734	add $grp aio_read $fh, 0, (-s $fh), $$data, 0, sub {
546	$grp->result ($_[0]);	735	$grp->result ($_[0]);
547	};
548	};	736	};
549
550	$grp
551	}	737	};
		738
		739	$grp
552	}	740	}
553		741
554	=item aio_copy $srcpath, $dstpath, $callback->($status)	742	=item aio_copy $srcpath, $dstpath, $callback->($status)
555		743
556	Try to copy the I<file> (directories not supported as either source or	744	Try to copy the I<file> (directories not supported as either source or
557	destination) from C<$srcpath> to C<$dstpath> and call the callback with	745	destination) from C<$srcpath> to C<$dstpath> and call the callback with
558	the C<0> (error) or C<-1> ok.	746	a status of C<0> (ok) or C<-1> (error, see C<$!>).
559		747
560	This is a composite request that it creates the destination file with	748	This is a composite request that creates the destination file with
561	mode 0200 and copies the contents of the source file into it using	749	mode 0200 and copies the contents of the source file into it using
562	C<aio_sendfile>, followed by restoring atime, mtime, access mode and	750	C<aio_sendfile>, followed by restoring atime, mtime, access mode and
563	uid/gid, in that order.	751	uid/gid, in that order.
564		752
565	If an error occurs, the partial destination file will be unlinked, if	753	If an error occurs, the partial destination file will be unlinked, if
…		…
567	errors are being ignored.	755	errors are being ignored.
568		756
569	=cut	757	=cut
570		758
571	sub aio_copy($$;$) {	759	sub aio_copy($$;$) {
572	aio_block {
573	my ($src, $dst, $cb) = @_;	760	my ($src, $dst, $cb) = @_;
574		761
575	my $pri = aioreq_pri;	762	my $pri = aioreq_pri;
576	my $grp = aio_group $cb;	763	my $grp = aio_group $cb;
577		764
578	aioreq_pri $pri;	765	aioreq_pri $pri;
579	add $grp aio_open $src, O_RDONLY, 0, sub {	766	add $grp aio_open $src, O_RDONLY, 0, sub {
580	if (my $src_fh = $_[0]) {	767	if (my $src_fh = $_[0]) {
581	my @stat = stat $src_fh;	768	my @stat = stat $src_fh; # hmm, might block over nfs?
582		769
583	aioreq_pri $pri;	770	aioreq_pri $pri;
584	add $grp aio_open $dst, O_CREAT \| O_WRONLY \| O_TRUNC, 0200, sub {	771	add $grp aio_open $dst, O_CREAT \| O_WRONLY \| O_TRUNC, 0200, sub {
585	if (my $dst_fh = $_[0]) {	772	if (my $dst_fh = $_[0]) {
586	aioreq_pri $pri;	773	aioreq_pri $pri;
587	add $grp aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub {	774	add $grp aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub {
588	if ($_[0] == $stat[7]) {	775	if ($_[0] == $stat[7]) {
589	$grp->result (0);	776	$grp->result (0);
590	close $src_fh;	777	close $src_fh;
591		778
592	# those should not normally block. should. should.
593	utime $stat[8], $stat[9], $dst;
594	chmod $stat[2] & 07777, $dst_fh;
595	chown $stat[4], $stat[5], $dst_fh;
596	close $dst_fh;
597	} else {	779	my $ch = sub {
598	$grp->result (-1);
599	close $src_fh;
600	close $dst_fh;
601
602	aioreq $pri;	780	aioreq_pri $pri;
		781	add $grp aio_chmod $dst_fh, $stat[2] & 07777, sub {
		782	aioreq_pri $pri;
		783	add $grp aio_chown $dst_fh, $stat[4], $stat[5], sub {
		784	aioreq_pri $pri;
603	add $grp aio_unlink $dst;	785	add $grp aio_close $dst_fh;
		786	}
		787	};
604	}	788	};
		789
		790	aioreq_pri $pri;
		791	add $grp aio_utime $dst_fh, $stat[8], $stat[9], sub {
		792	if ($_[0] < 0 && $! == ENOSYS) {
		793	aioreq_pri $pri;
		794	add $grp aio_utime $dst, $stat[8], $stat[9], $ch;
		795	} else {
		796	$ch->();
		797	}
		798	};
		799	} else {
		800	$grp->result (-1);
		801	close $src_fh;
		802	close $dst_fh;
		803
		804	aioreq $pri;
		805	add $grp aio_unlink $dst;
605	};	806	}
606	} else {
607	$grp->result (-1);
608	}	807	};
		808	} else {
		809	$grp->result (-1);
609	},	810	}
610
611	} else {
612	$grp->result (-1);
613	}	811	},
		812
		813	} else {
		814	$grp->result (-1);
614	};	815	}
615
616	$grp
617	}	816	};
		817
		818	$grp
618	}	819	}
619		820
620	=item aio_move $srcpath, $dstpath, $callback->($status)	821	=item aio_move $srcpath, $dstpath, $callback->($status)
621		822
622	Try to move the I<file> (directories not supported as either source or	823	Try to move the I<file> (directories not supported as either source or
623	destination) from C<$srcpath> to C<$dstpath> and call the callback with	824	destination) from C<$srcpath> to C<$dstpath> and call the callback with
624	the C<0> (error) or C<-1> ok.	825	a status of C<0> (ok) or C<-1> (error, see C<$!>).
625		826
626	This is a composite request that tries to rename(2) the file first. If	827	This is a composite request that tries to rename(2) the file first; if
627	rename files with C<EXDEV>, it copies the file with C<aio_copy> and, if	828	rename fails with C<EXDEV>, it copies the file with C<aio_copy> and, if
628	that is successful, unlinking the C<$srcpath>.	829	that is successful, unlinks the C<$srcpath>.
629		830
630	=cut	831	=cut
631		832
632	sub aio_move($$;$) {	833	sub aio_move($$;$) {
633	aio_block {
634	my ($src, $dst, $cb) = @_;	834	my ($src, $dst, $cb) = @_;
635		835
636	my $pri = aioreq_pri;	836	my $pri = aioreq_pri;
637	my $grp = aio_group $cb;	837	my $grp = aio_group $cb;
638		838
639	aioreq_pri $pri;	839	aioreq_pri $pri;
640	add $grp aio_rename $src, $dst, sub {	840	add $grp aio_rename $src, $dst, sub {
641	if ($_[0] && $! == EXDEV) {	841	if ($_[0] && $! == EXDEV) {
642	aioreq_pri $pri;	842	aioreq_pri $pri;
643	add $grp aio_copy $src, $dst, sub {	843	add $grp aio_copy $src, $dst, sub {
644	$grp->result ($_[0]);
645
646	if (!$_[0]) {
647	aioreq_pri $pri;
648	add $grp aio_unlink $src;
649	}
650	};
651	} else {
652	$grp->result ($_[0]);	844	$grp->result ($_[0]);
		845
		846	if (!$_[0]) {
		847	aioreq_pri $pri;
		848	add $grp aio_unlink $src;
		849	}
653	}	850	};
		851	} else {
		852	$grp->result ($_[0]);
654	};	853	}
655
656	$grp
657	}	854	};
		855
		856	$grp
658	}	857	}
659		858
660	=item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs)	859	=item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs)
661		860
662	Scans a directory (similar to C<aio_readdir>) but additionally tries to	861	Scans a directory (similar to C<aio_readdir>) but additionally tries to
…		…
682		881
683	Implementation notes.	882	Implementation notes.
684		883
685	The C<aio_readdir> cannot be avoided, but C<stat()>'ing every entry can.	884	The C<aio_readdir> cannot be avoided, but C<stat()>'ing every entry can.
686		885
		886	If readdir returns file type information, then this is used directly to
		887	find directories.
		888
687	After reading the directory, the modification time, size etc. of the	889	Otherwise, after reading the directory, the modification time, size etc.
688	directory before and after the readdir is checked, and if they match (and	890	of the directory before and after the readdir is checked, and if they
689	isn't the current time), the link count will be used to decide how many	891	match (and isn't the current time), the link count will be used to decide
690	entries are directories (if >= 2). Otherwise, no knowledge of the number	892	how many entries are directories (if >= 2). Otherwise, no knowledge of the
691	of subdirectories will be assumed.	893	number of subdirectories will be assumed.
692		894
693	Then entries will be sorted into likely directories (everything without	895	Then entries will be sorted into likely directories a non-initial dot
694	a non-initial dot currently) and likely non-directories (everything	896	currently) and likely non-directories (see C<aio_readdirx>). Then every
695	else). Then every entry plus an appended C</.> will be C<stat>'ed,	897	entry plus an appended C</.> will be C<stat>'ed, likely directories first,
696	likely directories first. If that succeeds, it assumes that the entry	898	in order of their inode numbers. If that succeeds, it assumes that the
697	is a directory or a symlink to directory (which will be checked	899	entry is a directory or a symlink to directory (which will be checked
698	seperately). This is often faster than stat'ing the entry itself because	900	seperately). This is often faster than stat'ing the entry itself because
699	filesystems might detect the type of the entry without reading the inode	901	filesystems might detect the type of the entry without reading the inode
700	data (e.g. ext2fs filetype feature).	902	data (e.g. ext2fs filetype feature), even on systems that cannot return
		903	the filetype information on readdir.
701		904
702	If the known number of directories (link count - 2) has been reached, the	905	If the known number of directories (link count - 2) has been reached, the
703	rest of the entries is assumed to be non-directories.	906	rest of the entries is assumed to be non-directories.
704		907
705	This only works with certainty on POSIX (= UNIX) filesystems, which	908	This only works with certainty on POSIX (= UNIX) filesystems, which
…		…
710	directory counting heuristic.	913	directory counting heuristic.
711		914
712	=cut	915	=cut
713		916
714	sub aio_scandir($$;$) {	917	sub aio_scandir($$;$) {
715	aio_block {
716	my ($path, $maxreq, $cb) = @_;	918	my ($path, $maxreq, $cb) = @_;
717		919
718	my $pri = aioreq_pri;	920	my $pri = aioreq_pri;
719		921
720	my $grp = aio_group $cb;	922	my $grp = aio_group $cb;
721		923
722	$maxreq = 4 if $maxreq <= 0;	924	$maxreq = 4 if $maxreq <= 0;
723		925
724	# stat once	926	# stat once
		927	aioreq_pri $pri;
		928	add $grp aio_stat $path, sub {
		929	return $grp->result () if $_[0];
		930	my $now = time;
		931	my $hash1 = join ":", (stat _)[0,1,3,7,9];
		932
		933	# read the directory entries
725	aioreq_pri $pri;	934	aioreq_pri $pri;
726	add $grp aio_stat $path, sub {	935	add $grp aio_readdirx $path, READDIR_DIRS_FIRST, sub {
		936	my $entries = shift
727	return $grp->result () if $_[0];	937	or return $grp->result ();
728	my $now = time;
729	my $hash1 = join ":", (stat _)[0,1,3,7,9];
730		938
731	# read the directory entries	939	# stat the dir another time
732	aioreq_pri $pri;	940	aioreq_pri $pri;
733	add $grp aio_readdir $path, sub {
734	my $entries = shift
735	or return $grp->result ();
736
737	# stat the dir another time
738	aioreq_pri $pri;
739	add $grp aio_stat $path, sub {	941	add $grp aio_stat $path, sub {
740	my $hash2 = join ":", (stat _)[0,1,3,7,9];	942	my $hash2 = join ":", (stat _)[0,1,3,7,9];
741		943
742	my $ndirs;	944	my $ndirs;
743		945
744	# take the slow route if anything looks fishy	946	# take the slow route if anything looks fishy
745	if ($hash1 ne $hash2 or (stat _)[9] == $now) {	947	if ($hash1 ne $hash2 or (stat _)[9] == $now) {
746	$ndirs = -1;	948	$ndirs = -1;
747	} else {	949	} else {
748	# if nlink == 2, we are finished	950	# if nlink == 2, we are finished
749	# on non-posix-fs's, we rely on nlink < 2	951	# for non-posix-fs's, we rely on nlink < 2
750	$ndirs = (stat _)[3] - 2	952	$ndirs = (stat _)[3] - 2
751	or return $grp->result ([], $entries);	953	or return $grp->result ([], $entries);
752	}	954	}
753		955
754	# sort into likely dirs and likely nondirs
755	# dirs == files without ".", short entries first
756	$entries = [map $_->[0],
757	sort { $b->[1] cmp $a->[1] }
758	map [$_, sprintf "%s%04d", (/.\./ ? "1" : "0"), length],
759	@$entries];
760
761	my (@dirs, @nondirs);	956	my (@dirs, @nondirs);
762		957
763	my $statgrp = add $grp aio_group sub {	958	my $statgrp = add $grp aio_group sub {
764	$grp->result (\@dirs, \@nondirs);	959	$grp->result (\@dirs, \@nondirs);
765	};	960	};
766		961
767	limit $statgrp $maxreq;	962	limit $statgrp $maxreq;
768	feed $statgrp sub {	963	feed $statgrp sub {
769	return unless @$entries;	964	return unless @$entries;
770	my $entry = pop @$entries;	965	my $entry = shift @$entries;
771		966
772	aioreq_pri $pri;	967	aioreq_pri $pri;
773	add $statgrp aio_stat "$path/$entry/.", sub {	968	add $statgrp aio_stat "$path/$entry/.", sub {
774	if ($_[0] < 0) {	969	if ($_[0] < 0) {
775	push @nondirs, $entry;	970	push @nondirs, $entry;
776	} else {	971	} else {
777	# need to check for real directory	972	# need to check for real directory
778	aioreq_pri $pri;	973	aioreq_pri $pri;
779	add $statgrp aio_lstat "$path/$entry", sub {	974	add $statgrp aio_lstat "$path/$entry", sub {
780	if (-d _) {	975	if (-d _) {
781	push @dirs, $entry;	976	push @dirs, $entry;
782		977
783	unless (--$ndirs) {	978	unless (--$ndirs) {
784	push @nondirs, @$entries;	979	push @nondirs, @$entries;
785	feed $statgrp;	980	feed $statgrp;
786	}
787	} else {
788	push @nondirs, $entry;
789	}	981	}
		982	} else {
		983	push @nondirs, $entry;
790	}	984	}
791	}	985	}
792	};	986	}
793	};	987	};
794	};	988	};
795	};	989	};
796	};	990	};
797
798	$grp
799	}	991	};
		992
		993	$grp
800	}	994	}
801		995
802	=item aio_rmtree $path, $callback->($status)	996	=item aio_rmtree $path, $callback->($status)
803		997
804	Delete a directory tree starting (and including) C<$path>, return the	998	Delete a directory tree starting (and including) C<$path>, return the
…		…
808		1002
809	=cut	1003	=cut
810		1004
811	sub aio_rmtree;	1005	sub aio_rmtree;
812	sub aio_rmtree($;$) {	1006	sub aio_rmtree($;$) {
813	aio_block {
814	my ($path, $cb) = @_;	1007	my ($path, $cb) = @_;
815		1008
816	my $pri = aioreq_pri;	1009	my $pri = aioreq_pri;
817	my $grp = aio_group $cb;	1010	my $grp = aio_group $cb;
818		1011
819	aioreq_pri $pri;	1012	aioreq_pri $pri;
820	add $grp aio_scandir $path, 0, sub {	1013	add $grp aio_scandir $path, 0, sub {
821	my ($dirs, $nondirs) = @_;	1014	my ($dirs, $nondirs) = @_;
822		1015
823	my $dirgrp = aio_group sub {	1016	my $dirgrp = aio_group sub {
824	add $grp aio_rmdir $path, sub {	1017	add $grp aio_rmdir $path, sub {
825	$grp->result ($_[0]);	1018	$grp->result ($_[0]);
826	};
827	};	1019	};
828
829	(aioreq_pri $pri), add $dirgrp aio_rmtree "$path/$_" for @$dirs;
830	(aioreq_pri $pri), add $dirgrp aio_unlink "$path/$_" for @$nondirs;
831
832	add $grp $dirgrp;
833	};	1020	};
834		1021
835	$grp	1022	(aioreq_pri $pri), add $dirgrp aio_rmtree "$path/$_" for @$dirs;
		1023	(aioreq_pri $pri), add $dirgrp aio_unlink "$path/$_" for @$nondirs;
		1024
		1025	add $grp $dirgrp;
836	}	1026	};
		1027
		1028	$grp
837	}	1029	}
		1030
		1031	=item aio_sync $callback->($status)
		1032
		1033	Asynchronously call sync and call the callback when finished.
838		1034
839	=item aio_fsync $fh, $callback->($status)	1035	=item aio_fsync $fh, $callback->($status)
840		1036
841	Asynchronously call fsync on the given filehandle and call the callback	1037	Asynchronously call fsync on the given filehandle and call the callback
842	with the fsync result code.	1038	with the fsync result code.
…		…
846	Asynchronously call fdatasync on the given filehandle and call the	1042	Asynchronously call fdatasync on the given filehandle and call the
847	callback with the fdatasync result code.	1043	callback with the fdatasync result code.
848		1044
849	If this call isn't available because your OS lacks it or it couldn't be	1045	If this call isn't available because your OS lacks it or it couldn't be
850	detected, it will be emulated by calling C<fsync> instead.	1046	detected, it will be emulated by calling C<fsync> instead.
		1047
		1048	=item aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status)
		1049
		1050	Sync the data portion of the file specified by C<$offset> and C<$length>
		1051	to disk (but NOT the metadata), by calling the Linux-specific
		1052	sync_file_range call. If sync_file_range is not available or it returns
		1053	ENOSYS, then fdatasync or fsync is being substituted.
		1054
		1055	C<$flags> can be a combination of C<IO::AIO::SYNC_FILE_RANGE_WAIT_BEFORE>,
		1056	C<IO::AIO::SYNC_FILE_RANGE_WRITE> and
		1057	C<IO::AIO::SYNC_FILE_RANGE_WAIT_AFTER>: refer to the sync_file_range
		1058	manpage for details.
		1059
		1060	=item aio_pathsync $path, $callback->($status)
		1061
		1062	This request tries to open, fsync and close the given path. This is a
		1063	composite request intended to sync directories after directory operations
		1064	(E.g. rename). This might not work on all operating systems or have any
		1065	specific effect, but usually it makes sure that directory changes get
		1066	written to disc. It works for anything that can be opened for read-only,
		1067	not just directories.
		1068
		1069	Future versions of this function might fall back to other methods when
		1070	C<fsync> on the directory fails (such as calling C<sync>).
		1071
		1072	Passes C<0> when everything went ok, and C<-1> on error.
		1073
		1074	=cut
		1075
		1076	sub aio_pathsync($;$) {
		1077	my ($path, $cb) = @_;
		1078
		1079	my $pri = aioreq_pri;
		1080	my $grp = aio_group $cb;
		1081
		1082	aioreq_pri $pri;
		1083	add $grp aio_open $path, O_RDONLY, 0, sub {
		1084	my ($fh) = @_;
		1085	if ($fh) {
		1086	aioreq_pri $pri;
		1087	add $grp aio_fsync $fh, sub {
		1088	$grp->result ($_[0]);
		1089
		1090	aioreq_pri $pri;
		1091	add $grp aio_close $fh;
		1092	};
		1093	} else {
		1094	$grp->result (-1);
		1095	}
		1096	};
		1097
		1098	$grp
		1099	}
		1100
		1101	=item aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
		1102
		1103	This is a rather advanced IO::AIO call, which only works on mmap(2)ed
		1104	scalars (see the C<IO::AIO::mmap> function, although it also works on data
		1105	scalars managed by the L<Sys::Mmap> or L<Mmap> modules, note that the
		1106	scalar must only be modified in-place while an aio operation is pending on
		1107	it).
		1108
		1109	It calls the C<msync> function of your OS, if available, with the memory
		1110	area starting at C<$offset> in the string and ending C<$length> bytes
		1111	later. If C<$length> is negative, counts from the end, and if C<$length>
		1112	is C<undef>, then it goes till the end of the string. The flags can be
		1113	a combination of C<IO::AIO::MS_ASYNC>, C<IO::AIO::MS_INVALIDATE> and
		1114	C<IO::AIO::MS_SYNC>.
		1115
		1116	=item aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
		1117
		1118	This is a rather advanced IO::AIO call, which works best on mmap(2)ed
		1119	scalars.
		1120
		1121	It touches (reads or writes) all memory pages in the specified
		1122	range inside the scalar. All caveats and parameters are the same
		1123	as for C<aio_msync>, above, except for flags, which must be either
		1124	C<0> (which reads all pages and ensures they are instantiated) or
		1125	C<IO::AIO::MT_MODIFY>, which modifies the memory page s(by reading and
		1126	writing an octet from it, which dirties the page).
		1127
		1128	=item aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status)
		1129
		1130	This is a rather advanced IO::AIO call, which works best on mmap(2)ed
		1131	scalars.
		1132
		1133	It reads in all the pages of the underlying storage into memory (if any)
		1134	and locks them, so they are not getting swapped/paged out or removed.
		1135
		1136	If C<$length> is undefined, then the scalar will be locked till the end.
		1137
		1138	On systems that do not implement C<mlock>, this function returns C<-1>
		1139	and sets errno to C<ENOSYS>.
		1140
		1141	Note that the corresponding C<munlock> is synchronous and is
		1142	documented under L<MISCELLANEOUS FUNCTIONS>.
		1143
		1144	Example: open a file, mmap and mlock it - both will be undone when
		1145	C<$data> gets destroyed.
		1146
		1147	open my $fh, "<", $path or die "$path: $!";
		1148	my $data;
		1149	IO::AIO::mmap $data, -s $fh, IO::AIO::PROT_READ, IO::AIO::MAP_SHARED, $fh;
		1150	aio_mlock $data; # mlock in background
		1151
		1152	=item aio_mlockall $flags, $callback->($status)
		1153
		1154	Calls the C<mlockall> function with the given C<$flags> (a combination of
		1155	C<IO::AIO::MCL_CURRENT> and C<IO::AIO::MCL_FUTURE>).
		1156
		1157	On systems that do not implement C<mlockall>, this function returns C<-1>
		1158	and sets errno to C<ENOSYS>.
		1159
		1160	Note that the corresponding C<munlockall> is synchronous and is
		1161	documented under L<MISCELLANEOUS FUNCTIONS>.
		1162
		1163	Example: asynchronously lock all current and future pages into memory.
		1164
		1165	aio_mlockall IO::AIO::MCL_FUTURE;
851		1166
852	=item aio_group $callback->(...)	1167	=item aio_group $callback->(...)
853		1168
854	This is a very special aio request: Instead of doing something, it is a	1169	This is a very special aio request: Instead of doing something, it is a
855	container for other aio requests, which is useful if you want to bundle	1170	container for other aio requests, which is useful if you want to bundle
…		…
905	=item cancel $req	1220	=item cancel $req
906		1221
907	Cancels the request, if possible. Has the effect of skipping execution	1222	Cancels the request, if possible. Has the effect of skipping execution
908	when entering the B<execute> state and skipping calling the callback when	1223	when entering the B<execute> state and skipping calling the callback when
909	entering the the B<result> state, but will leave the request otherwise	1224	entering the the B<result> state, but will leave the request otherwise
910	untouched. That means that requests that currently execute will not be	1225	untouched (with the exception of readdir). That means that requests that
911	stopped and resources held by the request will not be freed prematurely.	1226	currently execute will not be stopped and resources held by the request
		1227	will not be freed prematurely.
912		1228
913	=item cb $req $callback->(...)	1229	=item cb $req $callback->(...)
914		1230
915	Replace (or simply set) the callback registered to the request.	1231	Replace (or simply set) the callback registered to the request.
916		1232
…		…
967	Their lifetime, simplified, looks like this: when they are empty, they	1283	Their lifetime, simplified, looks like this: when they are empty, they
968	will finish very quickly. If they contain only requests that are in the	1284	will finish very quickly. If they contain only requests that are in the
969	C<done> state, they will also finish. Otherwise they will continue to	1285	C<done> state, they will also finish. Otherwise they will continue to
970	exist.	1286	exist.
971		1287
972	That means after creating a group you have some time to add requests. And	1288	That means after creating a group you have some time to add requests
973	in the callbacks of those requests, you can add further requests to the	1289	(precisely before the callback has been invoked, which is only done within
974	group. And only when all those requests have finished will the the group	1290	the C<poll_cb>). And in the callbacks of those requests, you can add
975	itself finish.	1291	further requests to the group. And only when all those requests have
		1292	finished will the the group itself finish.
976		1293
977	=over 4	1294	=over 4
978		1295
979	=item add $grp ...	1296	=item add $grp ...
980		1297
…		…
989	=item $grp->cancel_subs	1306	=item $grp->cancel_subs
990		1307
991	Cancel all subrequests and clears any feeder, but not the group request	1308	Cancel all subrequests and clears any feeder, but not the group request
992	itself. Useful when you queued a lot of events but got a result early.	1309	itself. Useful when you queued a lot of events but got a result early.
993		1310
		1311	The group request will finish normally (you cannot add requests to the
		1312	group).
		1313
994	=item $grp->result (...)	1314	=item $grp->result (...)
995		1315
996	Set the result value(s) that will be passed to the group callback when all	1316	Set the result value(s) that will be passed to the group callback when all
997	subrequests have finished and set thre groups errno to the current value	1317	subrequests have finished and set the groups errno to the current value
998	of errno (just like calling C<errno> without an error number). By default,	1318	of errno (just like calling C<errno> without an error number). By default,
999	no argument will be passed and errno is zero.	1319	no argument will be passed and errno is zero.
1000		1320
1001	=item $grp->errno ([$errno])	1321	=item $grp->errno ([$errno])
1002		1322
…		…
1013	=item feed $grp $callback->($grp)	1333	=item feed $grp $callback->($grp)
1014		1334
1015	Sets a feeder/generator on this group: every group can have an attached	1335	Sets a feeder/generator on this group: every group can have an attached
1016	generator that generates requests if idle. The idea behind this is that,	1336	generator that generates requests if idle. The idea behind this is that,
1017	although you could just queue as many requests as you want in a group,	1337	although you could just queue as many requests as you want in a group,
1018	this might starve other requests for a potentially long time. For	1338	this might starve other requests for a potentially long time. For example,
1019	example, C<aio_scandir> might generate hundreds of thousands C<aio_stat>	1339	C<aio_scandir> might generate hundreds of thousands C<aio_stat> requests,
1020	requests, delaying any later requests for a long time.	1340	delaying any later requests for a long time.
1021		1341
1022	To avoid this, and allow incremental generation of requests, you can	1342	To avoid this, and allow incremental generation of requests, you can
1023	instead a group and set a feeder on it that generates those requests. The	1343	instead a group and set a feeder on it that generates those requests. The
1024	feed callback will be called whenever there are few enough (see C<limit>,	1344	feed callback will be called whenever there are few enough (see C<limit>,
1025	below) requests active in the group itself and is expected to queue more	1345	below) requests active in the group itself and is expected to queue more
…		…
1029	not impose any limits).	1349	not impose any limits).
1030		1350
1031	If the feed does not queue more requests when called, it will be	1351	If the feed does not queue more requests when called, it will be
1032	automatically removed from the group.	1352	automatically removed from the group.
1033		1353
1034	If the feed limit is C<0>, it will be set to C<2> automatically.	1354	If the feed limit is C<0> when this method is called, it will be set to
		1355	C<2> automatically.
1035		1356
1036	Example:	1357	Example:
1037		1358
1038	# stat all files in @files, but only ever use four aio requests concurrently:	1359	# stat all files in @files, but only ever use four aio requests concurrently:
1039		1360
…		…
1051	Sets the feeder limit for the group: The feeder will be called whenever	1372	Sets the feeder limit for the group: The feeder will be called whenever
1052	the group contains less than this many requests.	1373	the group contains less than this many requests.
1053		1374
1054	Setting the limit to C<0> will pause the feeding process.	1375	Setting the limit to C<0> will pause the feeding process.
1055		1376
		1377	The default value for the limit is C<0>, but note that setting a feeder
		1378	automatically bumps it up to C<2>.
		1379
1056	=back	1380	=back
1057		1381
1058	=head2 SUPPORT FUNCTIONS	1382	=head2 SUPPORT FUNCTIONS
1059		1383
1060	=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION	1384	=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION
…		…
1062	=over 4	1386	=over 4
1063		1387
1064	=item $fileno = IO::AIO::poll_fileno	1388	=item $fileno = IO::AIO::poll_fileno
1065		1389
1066	Return the I<request result pipe file descriptor>. This filehandle must be	1390	Return the I<request result pipe file descriptor>. This filehandle must be
1067	polled for reading by some mechanism outside this module (e.g. Event or	1391	polled for reading by some mechanism outside this module (e.g. EV, Glib,
1068	select, see below or the SYNOPSIS). If the pipe becomes readable you have	1392	select and so on, see below or the SYNOPSIS). If the pipe becomes readable
1069	to call C<poll_cb> to check the results.	1393	you have to call C<poll_cb> to check the results.
1070		1394
1071	See C<poll_cb> for an example.	1395	See C<poll_cb> for an example.
1072		1396
1073	=item IO::AIO::poll_cb	1397	=item IO::AIO::poll_cb
1074		1398
1075	Process some outstanding events on the result pipe. You have to call this	1399	Process some outstanding events on the result pipe. You have to call this
1076	regularly. Returns the number of events processed. Returns immediately	1400	regularly. Returns C<0> if all events could be processed, or C<-1> if it
		1401	returned earlier for whatever reason. Returns immediately when no events
1077	when no events are outstanding. The amount of events processed depends on	1402	are outstanding. The amount of events processed depends on the settings of
1078	the settings of C<IO::AIO::max_poll_req> and C<IO::AIO::max_poll_time>.	1403	C<IO::AIO::max_poll_req> and C<IO::AIO::max_poll_time>.
1079		1404
1080	If not all requests were processed for whatever reason, the filehandle	1405	If not all requests were processed for whatever reason, the filehandle
1081	will still be ready when C<poll_cb> returns.	1406	will still be ready when C<poll_cb> returns, so normally you don't have to
		1407	do anything special to have it called later.
1082		1408
1083	Example: Install an Event watcher that automatically calls	1409	Example: Install an Event watcher that automatically calls
1084	IO::AIO::poll_cb with high priority:	1410	IO::AIO::poll_cb with high priority (more examples can be found in the
		1411	SYNOPSIS section, at the top of this document):
1085		1412
1086	Event->io (fd => IO::AIO::poll_fileno,	1413	Event->io (fd => IO::AIO::poll_fileno,
1087	poll => 'r', async => 1,	1414	poll => 'r', async => 1,
1088	cb => \&IO::AIO::poll_cb);	1415	cb => \&IO::AIO::poll_cb);
		1416
		1417	=item IO::AIO::poll_wait
		1418
		1419	If there are any outstanding requests and none of them in the result
		1420	phase, wait till the result filehandle becomes ready for reading (simply
		1421	does a C<select> on the filehandle. This is useful if you want to
		1422	synchronously wait for some requests to finish).
		1423
		1424	See C<nreqs> for an example.
		1425
		1426	=item IO::AIO::poll
		1427
		1428	Waits until some requests have been handled.
		1429
		1430	Returns the number of requests processed, but is otherwise strictly
		1431	equivalent to:
		1432
		1433	IO::AIO::poll_wait, IO::AIO::poll_cb
		1434
		1435	=item IO::AIO::flush
		1436
		1437	Wait till all outstanding AIO requests have been handled.
		1438
		1439	Strictly equivalent to:
		1440
		1441	IO::AIO::poll_wait, IO::AIO::poll_cb
		1442	while IO::AIO::nreqs;
1089		1443
1090	=item IO::AIO::max_poll_reqs $nreqs	1444	=item IO::AIO::max_poll_reqs $nreqs
1091		1445
1092	=item IO::AIO::max_poll_time $seconds	1446	=item IO::AIO::max_poll_time $seconds
1093		1447
…		…
1118	# use a low priority so other tasks have priority	1472	# use a low priority so other tasks have priority
1119	Event->io (fd => IO::AIO::poll_fileno,	1473	Event->io (fd => IO::AIO::poll_fileno,
1120	poll => 'r', nice => 1,	1474	poll => 'r', nice => 1,
1121	cb => &IO::AIO::poll_cb);	1475	cb => &IO::AIO::poll_cb);
1122		1476
1123	=item IO::AIO::poll_wait
1124
1125	If there are any outstanding requests and none of them in the result
1126	phase, wait till the result filehandle becomes ready for reading (simply
1127	does a C<select> on the filehandle. This is useful if you want to
1128	synchronously wait for some requests to finish).
1129
1130	See C<nreqs> for an example.
1131
1132	=item IO::AIO::poll
1133
1134	Waits until some requests have been handled.
1135
1136	Returns the number of requests processed, but is otherwise strictly
1137	equivalent to:
1138
1139	IO::AIO::poll_wait, IO::AIO::poll_cb
1140
1141	=item IO::AIO::flush
1142
1143	Wait till all outstanding AIO requests have been handled.
1144
1145	Strictly equivalent to:
1146
1147	IO::AIO::poll_wait, IO::AIO::poll_cb
1148	while IO::AIO::nreqs;
1149
1150	=back	1477	=back
1151		1478
1152	=head3 CONTROLLING THE NUMBER OF THREADS	1479	=head3 CONTROLLING THE NUMBER OF THREADS
1153		1480
1154	=over	1481	=over
…		…
1200		1527
1201	The default is probably ok in most situations, especially if thread	1528	The default is probably ok in most situations, especially if thread
1202	creation is fast. If thread creation is very slow on your system you might	1529	creation is fast. If thread creation is very slow on your system you might
1203	want to use larger values.	1530	want to use larger values.
1204		1531
1205	=item $oldmaxreqs = IO::AIO::max_outstanding $maxreqs	1532	=item IO::AIO::max_outstanding $maxreqs
1206		1533
1207	This is a very bad function to use in interactive programs because it	1534	This is a very bad function to use in interactive programs because it
1208	blocks, and a bad way to reduce concurrency because it is inexact: Better	1535	blocks, and a bad way to reduce concurrency because it is inexact: Better
1209	use an C<aio_group> together with a feed callback.	1536	use an C<aio_group> together with a feed callback.
1210		1537
…		…
1215		1542
1216	The default value is very large, so there is no practical limit on the	1543	The default value is very large, so there is no practical limit on the
1217	number of outstanding requests.	1544	number of outstanding requests.
1218		1545
1219	You can still queue as many requests as you want. Therefore,	1546	You can still queue as many requests as you want. Therefore,
1220	C<max_oustsanding> is mainly useful in simple scripts (with low values) or	1547	C<max_outstanding> is mainly useful in simple scripts (with low values) or
1221	as a stop gap to shield against fatal memory overflow (with large values).	1548	as a stop gap to shield against fatal memory overflow (with large values).
1222		1549
1223	=back	1550	=back
1224		1551
1225	=head3 STATISTICAL INFORMATION	1552	=head3 STATISTICAL INFORMATION
…		…
1246	Returns the number of requests currently in the pending state (executed,	1573	Returns the number of requests currently in the pending state (executed,
1247	but not yet processed by poll_cb).	1574	but not yet processed by poll_cb).
1248		1575
1249	=back	1576	=back
1250		1577
		1578	=head3 MISCELLANEOUS FUNCTIONS
		1579
		1580	IO::AIO implements some functions that might be useful, but are not
		1581	asynchronous.
		1582
		1583	=over 4
		1584
		1585	=item IO::AIO::sendfile $ofh, $ifh, $offset, $count
		1586
		1587	Calls the C<eio_sendfile_sync> function, which is like C<aio_sendfile>,
		1588	but is blocking (this makes most sense if you know the input data is
		1589	likely cached already and the output filehandle is set to non-blocking
		1590	operations).
		1591
		1592	Returns the number of bytes copied, or C<-1> on error.
		1593
		1594	=item IO::AIO::fadvise $fh, $offset, $len, $advice
		1595
		1596	Simply calls the C<posix_fadvise> function (see its
		1597	manpage for details). The following advice constants are
		1598	avaiable: C<IO::AIO::FADV_NORMAL>, C<IO::AIO::FADV_SEQUENTIAL>,
		1599	C<IO::AIO::FADV_RANDOM>, C<IO::AIO::FADV_NOREUSE>,
		1600	C<IO::AIO::FADV_WILLNEED>, C<IO::AIO::FADV_DONTNEED>.
		1601
		1602	On systems that do not implement C<posix_fadvise>, this function returns
		1603	ENOSYS, otherwise the return value of C<posix_fadvise>.
		1604
		1605	=item IO::AIO::madvise $scalar, $offset, $len, $advice
		1606
		1607	Simply calls the C<posix_madvise> function (see its
		1608	manpage for details). The following advice constants are
		1609	avaiable: C<IO::AIO::MADV_NORMAL>, C<IO::AIO::MADV_SEQUENTIAL>,
		1610	C<IO::AIO::MADV_RANDOM>, C<IO::AIO::MADV_WILLNEED>, C<IO::AIO::MADV_DONTNEED>.
		1611
		1612	On systems that do not implement C<posix_madvise>, this function returns
		1613	ENOSYS, otherwise the return value of C<posix_madvise>.
		1614
		1615	=item IO::AIO::mprotect $scalar, $offset, $len, $protect
		1616
		1617	Simply calls the C<mprotect> function on the preferably AIO::mmap'ed
		1618	$scalar (see its manpage for details). The following protect
		1619	constants are avaiable: C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_READ>,
		1620	C<IO::AIO::PROT_WRITE>, C<IO::AIO::PROT_EXEC>.
		1621
		1622	On systems that do not implement C<mprotect>, this function returns
		1623	ENOSYS, otherwise the return value of C<mprotect>.
		1624
		1625	=item IO::AIO::mmap $scalar, $length, $prot, $flags, $fh[, $offset]
		1626
		1627	Memory-maps a file (or anonymous memory range) and attaches it to the
		1628	given C<$scalar>, which will act like a string scalar.
		1629
		1630	The only operations allowed on the scalar are C<substr>/C<vec> that don't
		1631	change the string length, and most read-only operations such as copying it
		1632	or searching it with regexes and so on.
		1633
		1634	Anything else is unsafe and will, at best, result in memory leaks.
		1635
		1636	The memory map associated with the C<$scalar> is automatically removed
		1637	when the C<$scalar> is destroyed, or when the C<IO::AIO::mmap> or
		1638	C<IO::AIO::munmap> functions are called.
		1639
		1640	This calls the C<mmap>(2) function internally. See your system's manual
		1641	page for details on the C<$length>, C<$prot> and C<$flags> parameters.
		1642
		1643	The C<$length> must be larger than zero and smaller than the actual
		1644	filesize.
		1645
		1646	C<$prot> is a combination of C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_EXEC>,
		1647	C<IO::AIO::PROT_READ> and/or C<IO::AIO::PROT_WRITE>,
		1648
		1649	C<$flags> can be a combination of C<IO::AIO::MAP_SHARED> or
		1650	C<IO::AIO::MAP_PRIVATE>, or a number of system-specific flags (when
		1651	not available, the are defined as 0): C<IO::AIO::MAP_ANONYMOUS>
		1652	(which is set to C<MAP_ANON> if your system only provides this
		1653	constant), C<IO::AIO::MAP_HUGETLB>, C<IO::AIO::MAP_LOCKED>,
		1654	C<IO::AIO::MAP_NORESERVE>, C<IO::AIO::MAP_POPULATE> or
		1655	C<IO::AIO::MAP_NONBLOCK>
		1656
		1657	If C<$fh> is C<undef>, then a file descriptor of C<-1> is passed.
		1658
		1659	C<$offset> is the offset from the start of the file - it generally must be
		1660	a multiple of C<IO::AIO::PAGESIZE> and defaults to C<0>.
		1661
		1662	Example:
		1663
		1664	use Digest::MD5;
		1665	use IO::AIO;
		1666
		1667	open my $fh, "<verybigfile"
		1668	or die "$!";
		1669
		1670	IO::AIO::mmap my $data, -s $fh, IO::AIO::PROT_READ, IO::AIO::MAP_SHARED, $fh
		1671	or die "verybigfile: $!";
		1672
		1673	my $fast_md5 = md5 $data;
		1674
		1675	=item IO::AIO::munmap $scalar
		1676
		1677	Removes a previous mmap and undefines the C<$scalar>.
		1678
		1679	=item IO::AIO::munlock $scalar, $offset = 0, $length = undef
		1680
		1681	Calls the C<munlock> function, undoing the effects of a previous
		1682	C<aio_mlock> call (see its description for details).
		1683
		1684	=item IO::AIO::munlockall
		1685
		1686	Calls the C<munlockall> function.
		1687
		1688	On systems that do not implement C<munlockall>, this function returns
		1689	ENOSYS, otherwise the return value of C<munlockall>.
		1690
		1691	=back
		1692
1251	=cut	1693	=cut
1252		1694
1253	# support function to convert a fd into a perl filehandle
1254	sub _fd2fh {
1255	return undef if $_[0] < 0;
1256
1257	# try to generate nice filehandles
1258	my $sym = "IO::AIO::fd#$_[0]";
1259	local *$sym;
1260
1261	open *$sym, "+<&=$_[0]" # usually works under any unix
1262	or open *$sym, "<&=$_[0]" # cygwin needs this
1263	or open *$sym, ">&=$_[0]" # or this
1264	or return undef;
1265
1266	*$sym
1267	}
1268
1269	min_parallel 8;	1695	min_parallel 8;
1270		1696
1271	END { flush }	1697	END { flush }
1272		1698
1273	1;	1699	1;
		1700
		1701	=head1 EVENT LOOP INTEGRATION
		1702
		1703	It is recommended to use L<AnyEvent::AIO> to integrate IO::AIO
		1704	automatically into many event loops:
		1705
		1706	# AnyEvent integration (EV, Event, Glib, Tk, POE, urxvt, pureperl...)
		1707	use AnyEvent::AIO;
		1708
		1709	You can also integrate IO::AIO manually into many event loops, here are
		1710	some examples of how to do this:
		1711
		1712	# EV integration
		1713	my $aio_w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb;
		1714
		1715	# Event integration
		1716	Event->io (fd => IO::AIO::poll_fileno,
		1717	poll => 'r',
		1718	cb => \&IO::AIO::poll_cb);
		1719
		1720	# Glib/Gtk2 integration
		1721	add_watch Glib::IO IO::AIO::poll_fileno,
		1722	in => sub { IO::AIO::poll_cb; 1 };
		1723
		1724	# Tk integration
		1725	Tk::Event::IO->fileevent (IO::AIO::poll_fileno, "",
		1726	readable => \&IO::AIO::poll_cb);
		1727
		1728	# Danga::Socket integration
		1729	Danga::Socket->AddOtherFds (IO::AIO::poll_fileno =>
		1730	\&IO::AIO::poll_cb);
1274		1731
1275	=head2 FORK BEHAVIOUR	1732	=head2 FORK BEHAVIOUR
1276		1733
1277	This module should do "the right thing" when the process using it forks:	1734	This module should do "the right thing" when the process using it forks:
1278		1735
…		…
1311		1768
1312	Known bugs will be fixed in the next release.	1769	Known bugs will be fixed in the next release.
1313		1770
1314	=head1 SEE ALSO	1771	=head1 SEE ALSO
1315		1772
1316	L<Coro::AIO>.	1773	L<AnyEvent::AIO> for easy integration into event loops, L<Coro::AIO> for a
		1774	more natural syntax.
1317		1775
1318	=head1 AUTHOR	1776	=head1 AUTHOR
1319		1777
1320	Marc Lehmann <schmorp@schmorp.de>	1778	Marc Lehmann <schmorp@schmorp.de>
1321	http://home.schmorp.de/	1779	http://home.schmorp.de/

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Comparing IO-AIO/AIO.pm (file contents): Revision 1.113 by root, Thu Sep 20 14:06:21 2007 UTC vs. Revision 1.185 by root, Sat Dec 11 19:06:07 2010 UTC

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Comparing IO-AIO/AIO.pm (file contents):
Revision 1.113 by root, Thu Sep 20 14:06:21 2007 UTC vs.
Revision 1.185 by root, Sat Dec 11 19:06:07 2010 UTC