[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 1.184 by root, Mon Nov 1 22:03:43 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<$data> scalar I<MUST NOT> be modified in any way while the request
…		…
361	than one C<aio_sendfile> per C<$out_fh>, as they will interfere with each	430	than one C<aio_sendfile> per C<$out_fh>, as they will interfere with each
362	other.	431	other.
363		432
364	This call tries to make use of a native C<sendfile> syscall to provide	433	This call tries to make use of a native C<sendfile> syscall to provide
365	zero-copy operation. For this to work, C<$out_fh> should refer to a	434	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.	435	socket, and C<$in_fh> should refer to an mmap'able file.
367		436
368	If the native sendfile call fails or is not implemented, it will be	437	If a native sendfile cannot be found or it fails with C<ENOSYS>,
		438	C<ENOTSUP>, C<EOPNOTSUPP>, C<EAFNOSUPPORT>, C<EPROTOTYPE> or C<ENOTSOCK>,
369	emulated, so you can call C<aio_sendfile> on any type of filehandle	439	it will be emulated, so you can call C<aio_sendfile> on any type of
370	regardless of the limitations of the operating system.	440	filehandle regardless of the limitations of the operating system.
371		441
372	Please note, however, that C<aio_sendfile> can read more bytes from	442	Please note, however, that C<aio_sendfile> can read more bytes from
373	C<$in_fh> than are written, and there is no way to find out how many	443	C<$in_fh> than are written, and there is no way to find out how many
374	bytes have been read from C<aio_sendfile> alone, as C<aio_sendfile> only	444	bytes have been read from C<aio_sendfile> alone, as C<aio_sendfile> only
375	provides the number of bytes written to C<$out_fh>. Only if the result	445	provides the number of bytes written to C<$out_fh>. Only if the result
…		…
413	$_[0] and die "stat failed: $!";	483	$_[0] and die "stat failed: $!";
414	print "size is ", -s _, "\n";	484	print "size is ", -s _, "\n";
415	};	485	};
416		486
417		487
		488	=item aio_statvfs $fh_or_path, $callback->($statvfs)
		489
		490	Works like the POSIX C<statvfs> or C<fstatvfs> syscalls, depending on
		491	whether a file handle or path was passed.
		492
		493	On success, the callback is passed a hash reference with the following
		494	members: C<bsize>, C<frsize>, C<blocks>, C<bfree>, C<bavail>, C<files>,
		495	C<ffree>, C<favail>, C<fsid>, C<flag> and C<namemax>. On failure, C<undef>
		496	is passed.
		497
		498	The following POSIX IO::AIO::ST_* constants are defined: C<ST_RDONLY> and
		499	C<ST_NOSUID>.
		500
		501	The following non-POSIX IO::AIO::ST_* flag masks are defined to
		502	their correct value when available, or to C<0> on systems that do
		503	not support them: C<ST_NODEV>, C<ST_NOEXEC>, C<ST_SYNCHRONOUS>,
		504	C<ST_MANDLOCK>, C<ST_WRITE>, C<ST_APPEND>, C<ST_IMMUTABLE>, C<ST_NOATIME>,
		505	C<ST_NODIRATIME> and C<ST_RELATIME>.
		506
		507	Example: stat C</wd> and dump out the data if successful.
		508
		509	aio_statvfs "/wd", sub {
		510	my $f = $_[0]
		511	or die "statvfs: $!";
		512
		513	use Data::Dumper;
		514	say Dumper $f;
		515	};
		516
		517	# result:
		518	{
		519	bsize => 1024,
		520	bfree => 4333064312,
		521	blocks => 10253828096,
		522	files => 2050765568,
		523	flag => 4096,
		524	favail => 2042092649,
		525	bavail => 4333064312,
		526	ffree => 2042092649,
		527	namemax => 255,
		528	frsize => 1024,
		529	fsid => 1810
		530	}
		531
		532
418	=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status)	533	=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
419		534
420	Works like perl's C<utime> function (including the special case of $atime	535	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	536	and $mtime being undef). Fractional times are supported if the underlying
422	syscalls support them.	537	syscalls support them.
…		…
515		630
516	Unlike the POSIX call of the same name, C<aio_readdir> reads an entire	631	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	632	directory (i.e. opendir + readdir + closedir). The entries will not be
518	sorted, and will B<NOT> include the C<.> and C<..> entries.	633	sorted, and will B<NOT> include the C<.> and C<..> entries.
519		634
520	The callback a single argument which is either C<undef> or an array-ref	635	The callback is passed a single argument which is either C<undef> or an
521	with the filenames.	636	array-ref with the filenames.
		637
		638
		639	=item aio_readdirx $pathname, $flags, $callback->($entries, $flags)
		640
		641	Quite similar to C<aio_readdir>, but the C<$flags> argument allows to tune
		642	behaviour and output format. In case of an error, C<$entries> will be
		643	C<undef>.
		644
		645	The flags are a combination of the following constants, ORed together (the
		646	flags will also be passed to the callback, possibly modified):
		647
		648	=over 4
		649
		650	=item IO::AIO::READDIR_DENTS
		651
		652	When this flag is off, then the callback gets an arrayref with of names
		653	only (as with C<aio_readdir>), otherwise it gets an arrayref with
		654	C<[$name, $type, $inode]> arrayrefs, each describing a single directory
		655	entry in more detail.
		656
		657	C<$name> is the name of the entry.
		658
		659	C<$type> is one of the C<IO::AIO::DT_xxx> constants:
		660
		661	C<IO::AIO::DT_UNKNOWN>, C<IO::AIO::DT_FIFO>, C<IO::AIO::DT_CHR>, C<IO::AIO::DT_DIR>,
		662	C<IO::AIO::DT_BLK>, C<IO::AIO::DT_REG>, C<IO::AIO::DT_LNK>, C<IO::AIO::DT_SOCK>,
		663	C<IO::AIO::DT_WHT>.
		664
		665	C<IO::AIO::DT_UNKNOWN> means just that: readdir does not know. If you need to
		666	know, you have to run stat yourself. Also, for speed reasons, the C<$type>
		667	scalars are read-only: you can not modify them.
		668
		669	C<$inode> is the inode number (which might not be exact on systems with 64
		670	bit inode numbers and 32 bit perls). This field has unspecified content on
		671	systems that do not deliver the inode information.
		672
		673	=item IO::AIO::READDIR_DIRS_FIRST
		674
		675	When this flag is set, then the names will be returned in an order where
		676	likely directories come first. This is useful when you need to quickly
		677	find directories, or you want to find all directories while avoiding to
		678	stat() each entry.
		679
		680	If the system returns type information in readdir, then this is used
		681	to find directories directly. Otherwise, likely directories are files
		682	beginning with ".", or otherwise files with no dots, of which files with
		683	short names are tried first.
		684
		685	=item IO::AIO::READDIR_STAT_ORDER
		686
		687	When this flag is set, then the names will be returned in an order
		688	suitable for stat()'ing each one. That is, when you plan to stat()
		689	all files in the given directory, then the returned order will likely
		690	be fastest.
		691
		692	If both this flag and C<IO::AIO::READDIR_DIRS_FIRST> are specified, then
		693	the likely dirs come first, resulting in a less optimal stat order.
		694
		695	=item IO::AIO::READDIR_FOUND_UNKNOWN
		696
		697	This flag should not be set when calling C<aio_readdirx>. Instead, it
		698	is being set by C<aio_readdirx>, when any of the C<$type>'s found were
		699	C<IO::AIO::DT_UNKNOWN>. The absense of this flag therefore indicates that all
		700	C<$type>'s are known, which can be used to speed up some algorithms.
		701
		702	=back
522		703
523		704
524	=item aio_load $path, $data, $callback->($status)	705	=item aio_load $path, $data, $callback->($status)
525		706
526	This is a composite request that tries to fully load the given file into	707	This is a composite request that tries to fully load the given file into
527	memory. Status is the same as with aio_read.	708	memory. Status is the same as with aio_read.
528		709
529	=cut	710	=cut
530		711
531	sub aio_load($$;$) {	712	sub aio_load($$;$) {
532	aio_block {
533	my ($path, undef, $cb) = @_;	713	my ($path, undef, $cb) = @_;
534	my $data = \$_[1];	714	my $data = \$_[1];
535		715
536	my $pri = aioreq_pri;	716	my $pri = aioreq_pri;
537	my $grp = aio_group $cb;	717	my $grp = aio_group $cb;
		718
		719	aioreq_pri $pri;
		720	add $grp aio_open $path, O_RDONLY, 0, sub {
		721	my $fh = shift
		722	or return $grp->result (-1);
538		723
539	aioreq_pri $pri;	724	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), $$data, 0, sub {	725	add $grp aio_read $fh, 0, (-s $fh), $$data, 0, sub {
546	$grp->result ($_[0]);	726	$grp->result ($_[0]);
547	};
548	};	727	};
549
550	$grp
551	}	728	};
		729
		730	$grp
552	}	731	}
553		732
554	=item aio_copy $srcpath, $dstpath, $callback->($status)	733	=item aio_copy $srcpath, $dstpath, $callback->($status)
555		734
556	Try to copy the I<file> (directories not supported as either source or	735	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	736	destination) from C<$srcpath> to C<$dstpath> and call the callback with
558	the C<0> (error) or C<-1> ok.	737	a status of C<0> (ok) or C<-1> (error, see C<$!>).
559		738
560	This is a composite request that it creates the destination file with	739	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	740	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	741	C<aio_sendfile>, followed by restoring atime, mtime, access mode and
563	uid/gid, in that order.	742	uid/gid, in that order.
564		743
565	If an error occurs, the partial destination file will be unlinked, if	744	If an error occurs, the partial destination file will be unlinked, if
…		…
567	errors are being ignored.	746	errors are being ignored.
568		747
569	=cut	748	=cut
570		749
571	sub aio_copy($$;$) {	750	sub aio_copy($$;$) {
572	aio_block {
573	my ($src, $dst, $cb) = @_;	751	my ($src, $dst, $cb) = @_;
574		752
575	my $pri = aioreq_pri;	753	my $pri = aioreq_pri;
576	my $grp = aio_group $cb;	754	my $grp = aio_group $cb;
577		755
578	aioreq_pri $pri;	756	aioreq_pri $pri;
579	add $grp aio_open $src, O_RDONLY, 0, sub {	757	add $grp aio_open $src, O_RDONLY, 0, sub {
580	if (my $src_fh = $_[0]) {	758	if (my $src_fh = $_[0]) {
581	my @stat = stat $src_fh;	759	my @stat = stat $src_fh; # hmm, might block over nfs?
582		760
583	aioreq_pri $pri;	761	aioreq_pri $pri;
584	add $grp aio_open $dst, O_CREAT \| O_WRONLY \| O_TRUNC, 0200, sub {	762	add $grp aio_open $dst, O_CREAT \| O_WRONLY \| O_TRUNC, 0200, sub {
585	if (my $dst_fh = $_[0]) {	763	if (my $dst_fh = $_[0]) {
586	aioreq_pri $pri;	764	aioreq_pri $pri;
587	add $grp aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub {	765	add $grp aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub {
588	if ($_[0] == $stat[7]) {	766	if ($_[0] == $stat[7]) {
589	$grp->result (0);	767	$grp->result (0);
590	close $src_fh;	768	close $src_fh;
591		769
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 {	770	my $ch = sub {
598	$grp->result (-1);
599	close $src_fh;
600	close $dst_fh;
601
602	aioreq $pri;	771	aioreq_pri $pri;
		772	add $grp aio_chmod $dst_fh, $stat[2] & 07777, sub {
		773	aioreq_pri $pri;
		774	add $grp aio_chown $dst_fh, $stat[4], $stat[5], sub {
		775	aioreq_pri $pri;
603	add $grp aio_unlink $dst;	776	add $grp aio_close $dst_fh;
		777	}
		778	};
604	}	779	};
		780
		781	aioreq_pri $pri;
		782	add $grp aio_utime $dst_fh, $stat[8], $stat[9], sub {
		783	if ($_[0] < 0 && $! == ENOSYS) {
		784	aioreq_pri $pri;
		785	add $grp aio_utime $dst, $stat[8], $stat[9], $ch;
		786	} else {
		787	$ch->();
		788	}
		789	};
		790	} else {
		791	$grp->result (-1);
		792	close $src_fh;
		793	close $dst_fh;
		794
		795	aioreq $pri;
		796	add $grp aio_unlink $dst;
605	};	797	}
606	} else {
607	$grp->result (-1);
608	}	798	};
		799	} else {
		800	$grp->result (-1);
609	},	801	}
610
611	} else {
612	$grp->result (-1);
613	}	802	},
		803
		804	} else {
		805	$grp->result (-1);
614	};	806	}
615
616	$grp
617	}	807	};
		808
		809	$grp
618	}	810	}
619		811
620	=item aio_move $srcpath, $dstpath, $callback->($status)	812	=item aio_move $srcpath, $dstpath, $callback->($status)
621		813
622	Try to move the I<file> (directories not supported as either source or	814	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	815	destination) from C<$srcpath> to C<$dstpath> and call the callback with
624	the C<0> (error) or C<-1> ok.	816	a status of C<0> (ok) or C<-1> (error, see C<$!>).
625		817
626	This is a composite request that tries to rename(2) the file first. If	818	This is a composite request that tries to rename(2) the file first; if
627	rename files with C<EXDEV>, it copies the file with C<aio_copy> and, if	819	rename fails with C<EXDEV>, it copies the file with C<aio_copy> and, if
628	that is successful, unlinking the C<$srcpath>.	820	that is successful, unlinks the C<$srcpath>.
629		821
630	=cut	822	=cut
631		823
632	sub aio_move($$;$) {	824	sub aio_move($$;$) {
633	aio_block {
634	my ($src, $dst, $cb) = @_;	825	my ($src, $dst, $cb) = @_;
635		826
636	my $pri = aioreq_pri;	827	my $pri = aioreq_pri;
637	my $grp = aio_group $cb;	828	my $grp = aio_group $cb;
638		829
639	aioreq_pri $pri;	830	aioreq_pri $pri;
640	add $grp aio_rename $src, $dst, sub {	831	add $grp aio_rename $src, $dst, sub {
641	if ($_[0] && $! == EXDEV) {	832	if ($_[0] && $! == EXDEV) {
642	aioreq_pri $pri;	833	aioreq_pri $pri;
643	add $grp aio_copy $src, $dst, sub {	834	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]);	835	$grp->result ($_[0]);
		836
		837	if (!$_[0]) {
		838	aioreq_pri $pri;
		839	add $grp aio_unlink $src;
		840	}
653	}	841	};
		842	} else {
		843	$grp->result ($_[0]);
654	};	844	}
655
656	$grp
657	}	845	};
		846
		847	$grp
658	}	848	}
659		849
660	=item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs)	850	=item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs)
661		851
662	Scans a directory (similar to C<aio_readdir>) but additionally tries to	852	Scans a directory (similar to C<aio_readdir>) but additionally tries to
…		…
682		872
683	Implementation notes.	873	Implementation notes.
684		874
685	The C<aio_readdir> cannot be avoided, but C<stat()>'ing every entry can.	875	The C<aio_readdir> cannot be avoided, but C<stat()>'ing every entry can.
686		876
		877	If readdir returns file type information, then this is used directly to
		878	find directories.
		879
687	After reading the directory, the modification time, size etc. of the	880	Otherwise, after reading the directory, the modification time, size etc.
688	directory before and after the readdir is checked, and if they match (and	881	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	882	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	883	how many entries are directories (if >= 2). Otherwise, no knowledge of the
691	of subdirectories will be assumed.	884	number of subdirectories will be assumed.
692		885
693	Then entries will be sorted into likely directories (everything without	886	Then entries will be sorted into likely directories a non-initial dot
694	a non-initial dot currently) and likely non-directories (everything	887	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,	888	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	889	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	890	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	891	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	892	filesystems might detect the type of the entry without reading the inode
700	data (e.g. ext2fs filetype feature).	893	data (e.g. ext2fs filetype feature), even on systems that cannot return
		894	the filetype information on readdir.
701		895
702	If the known number of directories (link count - 2) has been reached, the	896	If the known number of directories (link count - 2) has been reached, the
703	rest of the entries is assumed to be non-directories.	897	rest of the entries is assumed to be non-directories.
704		898
705	This only works with certainty on POSIX (= UNIX) filesystems, which	899	This only works with certainty on POSIX (= UNIX) filesystems, which
…		…
710	directory counting heuristic.	904	directory counting heuristic.
711		905
712	=cut	906	=cut
713		907
714	sub aio_scandir($$;$) {	908	sub aio_scandir($$;$) {
715	aio_block {
716	my ($path, $maxreq, $cb) = @_;	909	my ($path, $maxreq, $cb) = @_;
717		910
718	my $pri = aioreq_pri;	911	my $pri = aioreq_pri;
719		912
720	my $grp = aio_group $cb;	913	my $grp = aio_group $cb;
721		914
722	$maxreq = 4 if $maxreq <= 0;	915	$maxreq = 4 if $maxreq <= 0;
723		916
724	# stat once	917	# stat once
		918	aioreq_pri $pri;
		919	add $grp aio_stat $path, sub {
		920	return $grp->result () if $_[0];
		921	my $now = time;
		922	my $hash1 = join ":", (stat _)[0,1,3,7,9];
		923
		924	# read the directory entries
725	aioreq_pri $pri;	925	aioreq_pri $pri;
726	add $grp aio_stat $path, sub {	926	add $grp aio_readdirx $path, READDIR_DIRS_FIRST, sub {
		927	my $entries = shift
727	return $grp->result () if $_[0];	928	or return $grp->result ();
728	my $now = time;
729	my $hash1 = join ":", (stat _)[0,1,3,7,9];
730		929
731	# read the directory entries	930	# stat the dir another time
732	aioreq_pri $pri;	931	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 {	932	add $grp aio_stat $path, sub {
740	my $hash2 = join ":", (stat _)[0,1,3,7,9];	933	my $hash2 = join ":", (stat _)[0,1,3,7,9];
741		934
742	my $ndirs;	935	my $ndirs;
743		936
744	# take the slow route if anything looks fishy	937	# take the slow route if anything looks fishy
745	if ($hash1 ne $hash2 or (stat _)[9] == $now) {	938	if ($hash1 ne $hash2 or (stat _)[9] == $now) {
746	$ndirs = -1;	939	$ndirs = -1;
747	} else {	940	} else {
748	# if nlink == 2, we are finished	941	# if nlink == 2, we are finished
749	# on non-posix-fs's, we rely on nlink < 2	942	# for non-posix-fs's, we rely on nlink < 2
750	$ndirs = (stat _)[3] - 2	943	$ndirs = (stat _)[3] - 2
751	or return $grp->result ([], $entries);	944	or return $grp->result ([], $entries);
752	}	945	}
753		946
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);	947	my (@dirs, @nondirs);
762		948
763	my $statgrp = add $grp aio_group sub {	949	my $statgrp = add $grp aio_group sub {
764	$grp->result (\@dirs, \@nondirs);	950	$grp->result (\@dirs, \@nondirs);
765	};	951	};
766		952
767	limit $statgrp $maxreq;	953	limit $statgrp $maxreq;
768	feed $statgrp sub {	954	feed $statgrp sub {
769	return unless @$entries;	955	return unless @$entries;
770	my $entry = pop @$entries;	956	my $entry = shift @$entries;
771		957
772	aioreq_pri $pri;	958	aioreq_pri $pri;
773	add $statgrp aio_stat "$path/$entry/.", sub {	959	add $statgrp aio_stat "$path/$entry/.", sub {
774	if ($_[0] < 0) {	960	if ($_[0] < 0) {
775	push @nondirs, $entry;	961	push @nondirs, $entry;
776	} else {	962	} else {
777	# need to check for real directory	963	# need to check for real directory
778	aioreq_pri $pri;	964	aioreq_pri $pri;
779	add $statgrp aio_lstat "$path/$entry", sub {	965	add $statgrp aio_lstat "$path/$entry", sub {
780	if (-d _) {	966	if (-d _) {
781	push @dirs, $entry;	967	push @dirs, $entry;
782		968
783	unless (--$ndirs) {	969	unless (--$ndirs) {
784	push @nondirs, @$entries;	970	push @nondirs, @$entries;
785	feed $statgrp;	971	feed $statgrp;
786	}
787	} else {
788	push @nondirs, $entry;
789	}	972	}
		973	} else {
		974	push @nondirs, $entry;
790	}	975	}
791	}	976	}
792	};	977	}
793	};	978	};
794	};	979	};
795	};	980	};
796	};	981	};
797
798	$grp
799	}	982	};
		983
		984	$grp
800	}	985	}
801		986
802	=item aio_rmtree $path, $callback->($status)	987	=item aio_rmtree $path, $callback->($status)
803		988
804	Delete a directory tree starting (and including) C<$path>, return the	989	Delete a directory tree starting (and including) C<$path>, return the
…		…
808		993
809	=cut	994	=cut
810		995
811	sub aio_rmtree;	996	sub aio_rmtree;
812	sub aio_rmtree($;$) {	997	sub aio_rmtree($;$) {
813	aio_block {
814	my ($path, $cb) = @_;	998	my ($path, $cb) = @_;
815		999
816	my $pri = aioreq_pri;	1000	my $pri = aioreq_pri;
817	my $grp = aio_group $cb;	1001	my $grp = aio_group $cb;
818		1002
819	aioreq_pri $pri;	1003	aioreq_pri $pri;
820	add $grp aio_scandir $path, 0, sub {	1004	add $grp aio_scandir $path, 0, sub {
821	my ($dirs, $nondirs) = @_;	1005	my ($dirs, $nondirs) = @_;
822		1006
823	my $dirgrp = aio_group sub {	1007	my $dirgrp = aio_group sub {
824	add $grp aio_rmdir $path, sub {	1008	add $grp aio_rmdir $path, sub {
825	$grp->result ($_[0]);	1009	$grp->result ($_[0]);
826	};
827	};	1010	};
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	};	1011	};
834		1012
835	$grp	1013	(aioreq_pri $pri), add $dirgrp aio_rmtree "$path/$_" for @$dirs;
		1014	(aioreq_pri $pri), add $dirgrp aio_unlink "$path/$_" for @$nondirs;
		1015
		1016	add $grp $dirgrp;
836	}	1017	};
		1018
		1019	$grp
837	}	1020	}
		1021
		1022	=item aio_sync $callback->($status)
		1023
		1024	Asynchronously call sync and call the callback when finished.
838		1025
839	=item aio_fsync $fh, $callback->($status)	1026	=item aio_fsync $fh, $callback->($status)
840		1027
841	Asynchronously call fsync on the given filehandle and call the callback	1028	Asynchronously call fsync on the given filehandle and call the callback
842	with the fsync result code.	1029	with the fsync result code.
…		…
846	Asynchronously call fdatasync on the given filehandle and call the	1033	Asynchronously call fdatasync on the given filehandle and call the
847	callback with the fdatasync result code.	1034	callback with the fdatasync result code.
848		1035
849	If this call isn't available because your OS lacks it or it couldn't be	1036	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.	1037	detected, it will be emulated by calling C<fsync> instead.
		1038
		1039	=item aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status)
		1040
		1041	Sync the data portion of the file specified by C<$offset> and C<$length>
		1042	to disk (but NOT the metadata), by calling the Linux-specific
		1043	sync_file_range call. If sync_file_range is not available or it returns
		1044	ENOSYS, then fdatasync or fsync is being substituted.
		1045
		1046	C<$flags> can be a combination of C<IO::AIO::SYNC_FILE_RANGE_WAIT_BEFORE>,
		1047	C<IO::AIO::SYNC_FILE_RANGE_WRITE> and
		1048	C<IO::AIO::SYNC_FILE_RANGE_WAIT_AFTER>: refer to the sync_file_range
		1049	manpage for details.
		1050
		1051	=item aio_pathsync $path, $callback->($status)
		1052
		1053	This request tries to open, fsync and close the given path. This is a
		1054	composite request intended to sync directories after directory operations
		1055	(E.g. rename). This might not work on all operating systems or have any
		1056	specific effect, but usually it makes sure that directory changes get
		1057	written to disc. It works for anything that can be opened for read-only,
		1058	not just directories.
		1059
		1060	Future versions of this function might fall back to other methods when
		1061	C<fsync> on the directory fails (such as calling C<sync>).
		1062
		1063	Passes C<0> when everything went ok, and C<-1> on error.
		1064
		1065	=cut
		1066
		1067	sub aio_pathsync($;$) {
		1068	my ($path, $cb) = @_;
		1069
		1070	my $pri = aioreq_pri;
		1071	my $grp = aio_group $cb;
		1072
		1073	aioreq_pri $pri;
		1074	add $grp aio_open $path, O_RDONLY, 0, sub {
		1075	my ($fh) = @_;
		1076	if ($fh) {
		1077	aioreq_pri $pri;
		1078	add $grp aio_fsync $fh, sub {
		1079	$grp->result ($_[0]);
		1080
		1081	aioreq_pri $pri;
		1082	add $grp aio_close $fh;
		1083	};
		1084	} else {
		1085	$grp->result (-1);
		1086	}
		1087	};
		1088
		1089	$grp
		1090	}
		1091
		1092	=item aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
		1093
		1094	This is a rather advanced IO::AIO call, which only works on mmap(2)ed
		1095	scalars (see the C<IO::AIO::mmap> function, although it also works on data
		1096	scalars managed by the L<Sys::Mmap> or L<Mmap> modules, note that the
		1097	scalar must only be modified in-place while an aio operation is pending on
		1098	it).
		1099
		1100	It calls the C<msync> function of your OS, if available, with the memory
		1101	area starting at C<$offset> in the string and ending C<$length> bytes
		1102	later. If C<$length> is negative, counts from the end, and if C<$length>
		1103	is C<undef>, then it goes till the end of the string. The flags can be
		1104	a combination of C<IO::AIO::MS_ASYNC>, C<IO::AIO::MS_INVALIDATE> and
		1105	C<IO::AIO::MS_SYNC>.
		1106
		1107	=item aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
		1108
		1109	This is a rather advanced IO::AIO call, which works best on mmap(2)ed
		1110	scalars.
		1111
		1112	It touches (reads or writes) all memory pages in the specified
		1113	range inside the scalar. All caveats and parameters are the same
		1114	as for C<aio_msync>, above, except for flags, which must be either
		1115	C<0> (which reads all pages and ensures they are instantiated) or
		1116	C<IO::AIO::MT_MODIFY>, which modifies the memory page s(by reading and
		1117	writing an octet from it, which dirties the page).
		1118
		1119	=item aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status)
		1120
		1121	This is a rather advanced IO::AIO call, which works best on mmap(2)ed
		1122	scalars.
		1123
		1124	It reads in all the pages of the underlying storage into memory (if any)
		1125	and locks them, so they are not getting swapped/paged out or removed.
		1126
		1127	If C<$length> is undefined, then the scalar will be locked till the end.
		1128
		1129	On systems that do not implement C<mlock>, this function returns C<-1>
		1130	and sets errno to C<ENOSYS>.
		1131
		1132	Note that the corresponding C<munlock> is synchronous and is
		1133	documented under L<MISCELLANEOUS FUNCTIONS>.
		1134
		1135	Example: open a file, mmap and mlock it - both will be undone when
		1136	C<$data> gets destroyed.
		1137
		1138	open my $fh, "<", $path or die "$path: $!";
		1139	my $data;
		1140	IO::AIO::mmap $data, -s $fh, IO::AIO::PROT_READ, IO::AIO::MAP_SHARED, $fh;
		1141	aio_mlock $data; # mlock in background
		1142
		1143	=item aio_mlockall $flags, $callback->($status)
		1144
		1145	Calls the C<mlockall> function with the given C<$flags> (a combination of
		1146	C<IO::AIO::MCL_CURRENT> and C<IO::AIO::MCL_FUTURE>).
		1147
		1148	On systems that do not implement C<mlockall>, this function returns C<-1>
		1149	and sets errno to C<ENOSYS>.
		1150
		1151	Note that the corresponding C<munlockall> is synchronous and is
		1152	documented under L<MISCELLANEOUS FUNCTIONS>.
		1153
		1154	Example: asynchronously lock all current and future pages into memory.
		1155
		1156	aio_mlockall IO::AIO::MCL_FUTURE;
851		1157
852	=item aio_group $callback->(...)	1158	=item aio_group $callback->(...)
853		1159
854	This is a very special aio request: Instead of doing something, it is a	1160	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	1161	container for other aio requests, which is useful if you want to bundle
…		…
905	=item cancel $req	1211	=item cancel $req
906		1212
907	Cancels the request, if possible. Has the effect of skipping execution	1213	Cancels the request, if possible. Has the effect of skipping execution
908	when entering the B<execute> state and skipping calling the callback when	1214	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	1215	entering the the B<result> state, but will leave the request otherwise
910	untouched. That means that requests that currently execute will not be	1216	untouched (with the exception of readdir). That means that requests that
911	stopped and resources held by the request will not be freed prematurely.	1217	currently execute will not be stopped and resources held by the request
		1218	will not be freed prematurely.
912		1219
913	=item cb $req $callback->(...)	1220	=item cb $req $callback->(...)
914		1221
915	Replace (or simply set) the callback registered to the request.	1222	Replace (or simply set) the callback registered to the request.
916		1223
…		…
967	Their lifetime, simplified, looks like this: when they are empty, they	1274	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	1275	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	1276	C<done> state, they will also finish. Otherwise they will continue to
970	exist.	1277	exist.
971		1278
972	That means after creating a group you have some time to add requests. And	1279	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	1280	(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	1281	the C<poll_cb>). And in the callbacks of those requests, you can add
975	itself finish.	1282	further requests to the group. And only when all those requests have
		1283	finished will the the group itself finish.
976		1284
977	=over 4	1285	=over 4
978		1286
979	=item add $grp ...	1287	=item add $grp ...
980		1288
…		…
989	=item $grp->cancel_subs	1297	=item $grp->cancel_subs
990		1298
991	Cancel all subrequests and clears any feeder, but not the group request	1299	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.	1300	itself. Useful when you queued a lot of events but got a result early.
993		1301
		1302	The group request will finish normally (you cannot add requests to the
		1303	group).
		1304
994	=item $grp->result (...)	1305	=item $grp->result (...)
995		1306
996	Set the result value(s) that will be passed to the group callback when all	1307	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	1308	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,	1309	of errno (just like calling C<errno> without an error number). By default,
999	no argument will be passed and errno is zero.	1310	no argument will be passed and errno is zero.
1000		1311
1001	=item $grp->errno ([$errno])	1312	=item $grp->errno ([$errno])
1002		1313
…		…
1013	=item feed $grp $callback->($grp)	1324	=item feed $grp $callback->($grp)
1014		1325
1015	Sets a feeder/generator on this group: every group can have an attached	1326	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,	1327	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,	1328	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	1329	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>	1330	C<aio_scandir> might generate hundreds of thousands C<aio_stat> requests,
1020	requests, delaying any later requests for a long time.	1331	delaying any later requests for a long time.
1021		1332
1022	To avoid this, and allow incremental generation of requests, you can	1333	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	1334	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>,	1335	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	1336	below) requests active in the group itself and is expected to queue more
…		…
1029	not impose any limits).	1340	not impose any limits).
1030		1341
1031	If the feed does not queue more requests when called, it will be	1342	If the feed does not queue more requests when called, it will be
1032	automatically removed from the group.	1343	automatically removed from the group.
1033		1344
1034	If the feed limit is C<0>, it will be set to C<2> automatically.	1345	If the feed limit is C<0> when this method is called, it will be set to
		1346	C<2> automatically.
1035		1347
1036	Example:	1348	Example:
1037		1349
1038	# stat all files in @files, but only ever use four aio requests concurrently:	1350	# stat all files in @files, but only ever use four aio requests concurrently:
1039		1351
…		…
1051	Sets the feeder limit for the group: The feeder will be called whenever	1363	Sets the feeder limit for the group: The feeder will be called whenever
1052	the group contains less than this many requests.	1364	the group contains less than this many requests.
1053		1365
1054	Setting the limit to C<0> will pause the feeding process.	1366	Setting the limit to C<0> will pause the feeding process.
1055		1367
		1368	The default value for the limit is C<0>, but note that setting a feeder
		1369	automatically bumps it up to C<2>.
		1370
1056	=back	1371	=back
1057		1372
1058	=head2 SUPPORT FUNCTIONS	1373	=head2 SUPPORT FUNCTIONS
1059		1374
1060	=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION	1375	=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION
…		…
1062	=over 4	1377	=over 4
1063		1378
1064	=item $fileno = IO::AIO::poll_fileno	1379	=item $fileno = IO::AIO::poll_fileno
1065		1380
1066	Return the I<request result pipe file descriptor>. This filehandle must be	1381	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	1382	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	1383	select and so on, see below or the SYNOPSIS). If the pipe becomes readable
1069	to call C<poll_cb> to check the results.	1384	you have to call C<poll_cb> to check the results.
1070		1385
1071	See C<poll_cb> for an example.	1386	See C<poll_cb> for an example.
1072		1387
1073	=item IO::AIO::poll_cb	1388	=item IO::AIO::poll_cb
1074		1389
1075	Process some outstanding events on the result pipe. You have to call this	1390	Process some outstanding events on the result pipe. You have to call this
1076	regularly. Returns the number of events processed. Returns immediately	1391	regularly. Returns C<0> if all events could be processed, or C<-1> if it
		1392	returned earlier for whatever reason. Returns immediately when no events
1077	when no events are outstanding. The amount of events processed depends on	1393	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>.	1394	C<IO::AIO::max_poll_req> and C<IO::AIO::max_poll_time>.
1079		1395
1080	If not all requests were processed for whatever reason, the filehandle	1396	If not all requests were processed for whatever reason, the filehandle
1081	will still be ready when C<poll_cb> returns.	1397	will still be ready when C<poll_cb> returns, so normally you don't have to
		1398	do anything special to have it called later.
1082		1399
1083	Example: Install an Event watcher that automatically calls	1400	Example: Install an Event watcher that automatically calls
1084	IO::AIO::poll_cb with high priority:	1401	IO::AIO::poll_cb with high priority (more examples can be found in the
		1402	SYNOPSIS section, at the top of this document):
1085		1403
1086	Event->io (fd => IO::AIO::poll_fileno,	1404	Event->io (fd => IO::AIO::poll_fileno,
1087	poll => 'r', async => 1,	1405	poll => 'r', async => 1,
1088	cb => \&IO::AIO::poll_cb);	1406	cb => \&IO::AIO::poll_cb);
		1407
		1408	=item IO::AIO::poll_wait
		1409
		1410	If there are any outstanding requests and none of them in the result
		1411	phase, wait till the result filehandle becomes ready for reading (simply
		1412	does a C<select> on the filehandle. This is useful if you want to
		1413	synchronously wait for some requests to finish).
		1414
		1415	See C<nreqs> for an example.
		1416
		1417	=item IO::AIO::poll
		1418
		1419	Waits until some requests have been handled.
		1420
		1421	Returns the number of requests processed, but is otherwise strictly
		1422	equivalent to:
		1423
		1424	IO::AIO::poll_wait, IO::AIO::poll_cb
		1425
		1426	=item IO::AIO::flush
		1427
		1428	Wait till all outstanding AIO requests have been handled.
		1429
		1430	Strictly equivalent to:
		1431
		1432	IO::AIO::poll_wait, IO::AIO::poll_cb
		1433	while IO::AIO::nreqs;
1089		1434
1090	=item IO::AIO::max_poll_reqs $nreqs	1435	=item IO::AIO::max_poll_reqs $nreqs
1091		1436
1092	=item IO::AIO::max_poll_time $seconds	1437	=item IO::AIO::max_poll_time $seconds
1093		1438
…		…
1118	# use a low priority so other tasks have priority	1463	# use a low priority so other tasks have priority
1119	Event->io (fd => IO::AIO::poll_fileno,	1464	Event->io (fd => IO::AIO::poll_fileno,
1120	poll => 'r', nice => 1,	1465	poll => 'r', nice => 1,
1121	cb => &IO::AIO::poll_cb);	1466	cb => &IO::AIO::poll_cb);
1122		1467
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	1468	=back
1151		1469
1152	=head3 CONTROLLING THE NUMBER OF THREADS	1470	=head3 CONTROLLING THE NUMBER OF THREADS
1153		1471
1154	=over	1472	=over
…		…
1200		1518
1201	The default is probably ok in most situations, especially if thread	1519	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	1520	creation is fast. If thread creation is very slow on your system you might
1203	want to use larger values.	1521	want to use larger values.
1204		1522
1205	=item $oldmaxreqs = IO::AIO::max_outstanding $maxreqs	1523	=item IO::AIO::max_outstanding $maxreqs
1206		1524
1207	This is a very bad function to use in interactive programs because it	1525	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	1526	blocks, and a bad way to reduce concurrency because it is inexact: Better
1209	use an C<aio_group> together with a feed callback.	1527	use an C<aio_group> together with a feed callback.
1210		1528
…		…
1215		1533
1216	The default value is very large, so there is no practical limit on the	1534	The default value is very large, so there is no practical limit on the
1217	number of outstanding requests.	1535	number of outstanding requests.
1218		1536
1219	You can still queue as many requests as you want. Therefore,	1537	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	1538	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).	1539	as a stop gap to shield against fatal memory overflow (with large values).
1222		1540
1223	=back	1541	=back
1224		1542
1225	=head3 STATISTICAL INFORMATION	1543	=head3 STATISTICAL INFORMATION
…		…
1246	Returns the number of requests currently in the pending state (executed,	1564	Returns the number of requests currently in the pending state (executed,
1247	but not yet processed by poll_cb).	1565	but not yet processed by poll_cb).
1248		1566
1249	=back	1567	=back
1250		1568
		1569	=head3 MISCELLANEOUS FUNCTIONS
		1570
		1571	IO::AIO implements some functions that might be useful, but are not
		1572	asynchronous.
		1573
		1574	=over 4
		1575
		1576	=item IO::AIO::sendfile $ofh, $ifh, $offset, $count
		1577
		1578	Calls the C<eio_sendfile_sync> function, which is like C<aio_sendfile>,
		1579	but is blocking (this makes most sense if you know the input data is
		1580	likely cached already and the output filehandle is set to non-blocking
		1581	operations).
		1582
		1583	Returns the number of bytes copied, or C<-1> on error.
		1584
		1585	=item IO::AIO::fadvise $fh, $offset, $len, $advice
		1586
		1587	Simply calls the C<posix_fadvise> function (see its
		1588	manpage for details). The following advice constants are
		1589	avaiable: C<IO::AIO::FADV_NORMAL>, C<IO::AIO::FADV_SEQUENTIAL>,
		1590	C<IO::AIO::FADV_RANDOM>, C<IO::AIO::FADV_NOREUSE>,
		1591	C<IO::AIO::FADV_WILLNEED>, C<IO::AIO::FADV_DONTNEED>.
		1592
		1593	On systems that do not implement C<posix_fadvise>, this function returns
		1594	ENOSYS, otherwise the return value of C<posix_fadvise>.
		1595
		1596	=item IO::AIO::madvise $scalar, $offset, $len, $advice
		1597
		1598	Simply calls the C<posix_madvise> function (see its
		1599	manpage for details). The following advice constants are
		1600	avaiable: C<IO::AIO::MADV_NORMAL>, C<IO::AIO::MADV_SEQUENTIAL>,
		1601	C<IO::AIO::MADV_RANDOM>, C<IO::AIO::MADV_WILLNEED>, C<IO::AIO::MADV_DONTNEED>.
		1602
		1603	On systems that do not implement C<posix_madvise>, this function returns
		1604	ENOSYS, otherwise the return value of C<posix_madvise>.
		1605
		1606	=item IO::AIO::mprotect $scalar, $offset, $len, $protect
		1607
		1608	Simply calls the C<mprotect> function on the preferably AIO::mmap'ed
		1609	$scalar (see its manpage for details). The following protect
		1610	constants are avaiable: C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_READ>,
		1611	C<IO::AIO::PROT_WRITE>, C<IO::AIO::PROT_EXEC>.
		1612
		1613	On systems that do not implement C<mprotect>, this function returns
		1614	ENOSYS, otherwise the return value of C<mprotect>.
		1615
		1616	=item IO::AIO::mmap $scalar, $length, $prot, $flags, $fh[, $offset]
		1617
		1618	Memory-maps a file (or anonymous memory range) and attaches it to the
		1619	given C<$scalar>, which will act like a string scalar.
		1620
		1621	The only operations allowed on the scalar are C<substr>/C<vec> that don't
		1622	change the string length, and most read-only operations such as copying it
		1623	or searching it with regexes and so on.
		1624
		1625	Anything else is unsafe and will, at best, result in memory leaks.
		1626
		1627	The memory map associated with the C<$scalar> is automatically removed
		1628	when the C<$scalar> is destroyed, or when the C<IO::AIO::mmap> or
		1629	C<IO::AIO::munmap> functions are called.
		1630
		1631	This calls the C<mmap>(2) function internally. See your system's manual
		1632	page for details on the C<$length>, C<$prot> and C<$flags> parameters.
		1633
		1634	The C<$length> must be larger than zero and smaller than the actual
		1635	filesize.
		1636
		1637	C<$prot> is a combination of C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_EXEC>,
		1638	C<IO::AIO::PROT_READ> and/or C<IO::AIO::PROT_WRITE>,
		1639
		1640	C<$flags> can be a combination of C<IO::AIO::MAP_SHARED> or
		1641	C<IO::AIO::MAP_PRIVATE>, or a number of system-specific flags (when
		1642	not available, the are defined as 0): C<IO::AIO::MAP_ANONYMOUS>
		1643	(which is set to C<MAP_ANON> if your system only provides this
		1644	constant), C<IO::AIO::MAP_HUGETLB>, C<IO::AIO::MAP_LOCKED>,
		1645	C<IO::AIO::MAP_NORESERVE>, C<IO::AIO::MAP_POPULATE> or
		1646	C<IO::AIO::MAP_NONBLOCK>
		1647
		1648	If C<$fh> is C<undef>, then a file descriptor of C<-1> is passed.
		1649
		1650	C<$offset> is the offset from the start of the file - it generally must be
		1651	a multiple of C<IO::AIO::PAGESIZE> and defaults to C<0>.
		1652
		1653	Example:
		1654
		1655	use Digest::MD5;
		1656	use IO::AIO;
		1657
		1658	open my $fh, "<verybigfile"
		1659	or die "$!";
		1660
		1661	IO::AIO::mmap my $data, -s $fh, IO::AIO::PROT_READ, IO::AIO::MAP_SHARED, $fh
		1662	or die "verybigfile: $!";
		1663
		1664	my $fast_md5 = md5 $data;
		1665
		1666	=item IO::AIO::munmap $scalar
		1667
		1668	Removes a previous mmap and undefines the C<$scalar>.
		1669
		1670	=item IO::AIO::munlock $scalar, $offset = 0, $length = undef
		1671
		1672	Calls the C<munlock> function, undoing the effects of a previous
		1673	C<aio_mlock> call (see its description for details).
		1674
		1675	=item IO::AIO::munlockall
		1676
		1677	Calls the C<munlockall> function.
		1678
		1679	On systems that do not implement C<munlockall>, this function returns
		1680	ENOSYS, otherwise the return value of C<munlockall>.
		1681
		1682	=back
		1683
1251	=cut	1684	=cut
1252		1685
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;	1686	min_parallel 8;
1270		1687
1271	END { flush }	1688	END { flush }
1272		1689
1273	1;	1690	1;
		1691
		1692	=head1 EVENT LOOP INTEGRATION
		1693
		1694	It is recommended to use L<AnyEvent::AIO> to integrate IO::AIO
		1695	automatically into many event loops:
		1696
		1697	# AnyEvent integration (EV, Event, Glib, Tk, POE, urxvt, pureperl...)
		1698	use AnyEvent::AIO;
		1699
		1700	You can also integrate IO::AIO manually into many event loops, here are
		1701	some examples of how to do this:
		1702
		1703	# EV integration
		1704	my $aio_w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb;
		1705
		1706	# Event integration
		1707	Event->io (fd => IO::AIO::poll_fileno,
		1708	poll => 'r',
		1709	cb => \&IO::AIO::poll_cb);
		1710
		1711	# Glib/Gtk2 integration
		1712	add_watch Glib::IO IO::AIO::poll_fileno,
		1713	in => sub { IO::AIO::poll_cb; 1 };
		1714
		1715	# Tk integration
		1716	Tk::Event::IO->fileevent (IO::AIO::poll_fileno, "",
		1717	readable => \&IO::AIO::poll_cb);
		1718
		1719	# Danga::Socket integration
		1720	Danga::Socket->AddOtherFds (IO::AIO::poll_fileno =>
		1721	\&IO::AIO::poll_cb);
1274		1722
1275	=head2 FORK BEHAVIOUR	1723	=head2 FORK BEHAVIOUR
1276		1724
1277	This module should do "the right thing" when the process using it forks:	1725	This module should do "the right thing" when the process using it forks:
1278		1726
…		…
1311		1759
1312	Known bugs will be fixed in the next release.	1760	Known bugs will be fixed in the next release.
1313		1761
1314	=head1 SEE ALSO	1762	=head1 SEE ALSO
1315		1763
1316	L<Coro::AIO>.	1764	L<AnyEvent::AIO> for easy integration into event loops, L<Coro::AIO> for a
		1765	more natural syntax.
1317		1766
1318	=head1 AUTHOR	1767	=head1 AUTHOR
1319		1768
1320	Marc Lehmann <schmorp@schmorp.de>	1769	Marc Lehmann <schmorp@schmorp.de>
1321	http://home.schmorp.de/	1770	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 1.184 by root, Mon Nov 1 22:03:43 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 1.184 by root, Mon Nov 1 22:03:43 2010 UTC