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

Comparing IO-AIO/AIO.pm (file contents):
Revision 1.146 by root, Tue Apr 21 20:06:05 2009 UTC vs.
Revision 1.189 by root, Sun Mar 27 10:26:08 2011 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 (EV, Event, Glib, Tk, POE, urxvt, pureperl...)
32	use AnyEvent::AIO;
33
34	# EV integration
35	my $w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb;
36
37	# Event integration
38	Event->io (fd => IO::AIO::poll_fileno,
39	poll => 'r',
40	cb => \&IO::AIO::poll_cb);
41
42	# Glib/Gtk2 integration
43	add_watch Glib::IO IO::AIO::poll_fileno,
44	in => sub { IO::AIO::poll_cb; 1 };
45
46	# Tk integration
47	Tk::Event::IO->fileevent (IO::AIO::poll_fileno, "",
48	readable => \&IO::AIO::poll_cb);
49
50	# Danga::Socket integration
51	Danga::Socket->AddOtherFds (IO::AIO::poll_fileno =>
52	\&IO::AIO::poll_cb);
53
54	=head1 DESCRIPTION	31	=head1 DESCRIPTION
55		32
56	This module implements asynchronous I/O using whatever means your	33	This module implements asynchronous I/O using whatever means your
57	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>).
58		36
59	Asynchronous means that operations that can normally block your program	37	Asynchronous means that operations that can normally block your program
60	(e.g. reading from disk) will be done asynchronously: the operation	38	(e.g. reading from disk) will be done asynchronously: the operation
61	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
62	is extremely useful for programs that need to stay interactive even	40	is extremely useful for programs that need to stay interactive even
…		…
66	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
67	concurrently.	45	concurrently.
68		46
69	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
70	example sockets), using these functions on file descriptors that	48	example sockets), using these functions on file descriptors that
71	support nonblocking operation (again, sockets, pipes etc.) is very	49	support nonblocking operation (again, sockets, pipes etc.) is
72	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>
73	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.
74		52
75	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
76	requests and signal their completion. You don't need thread support	54	requests and signal their completion. You don't need thread support
77	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
…		…
87	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
88	call C<poll_cb> (or other C<aio_> functions) recursively.	66	call C<poll_cb> (or other C<aio_> functions) recursively.
89		67
90	=head2 EXAMPLE	68	=head2 EXAMPLE
91		69
92	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
93	F</etc/passwd> asynchronously:	71	F</etc/passwd> asynchronously:
94		72
95	use Fcntl;	73	use Fcntl;
96	use Event;	74	use EV;
97	use IO::AIO;	75	use IO::AIO;
98		76
99	# register the IO::AIO callback with Event	77	# register the IO::AIO callback with EV
100	Event->io (fd => IO::AIO::poll_fileno,	78	my $aio_w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb;
101	poll => 'r',
102	cb => \&IO::AIO::poll_cb);
103		79
104	# queue the request to open /etc/passwd	80	# queue the request to open /etc/passwd
105	aio_open "/etc/passwd", O_RDONLY, 0, sub {	81	aio_open "/etc/passwd", IO::AIO::O_RDONLY, 0, sub {
106	my $fh = shift	82	my $fh = shift
107	or die "error while opening: $!";	83	or die "error while opening: $!";
108		84
109	# stat'ing filehandles is generally non-blocking	85	# stat'ing filehandles is generally non-blocking
110	my $size = -s $fh;	86	my $size = -s $fh;
…		…
119		95
120	# file contents now in $contents	96	# file contents now in $contents
121	print $contents;	97	print $contents;
122		98
123	# exit event loop and program	99	# exit event loop and program
124	Event::unloop;	100	EV::unloop;
125	};	101	};
126	};	102	};
127		103
128	# possibly queue up other requests, or open GUI windows,	104	# possibly queue up other requests, or open GUI windows,
129	# check for sockets etc. etc.	105	# check for sockets etc. etc.
130		106
131	# process events as long as there are some:	107	# process events as long as there are some:
132	Event::loop;	108	EV::loop;
133		109
134	=head1 REQUEST ANATOMY AND LIFETIME	110	=head1 REQUEST ANATOMY AND LIFETIME
135		111
136	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
137	directly visible to Perl.	113	directly visible to Perl.
…		…
187		163
188	package IO::AIO;	164	package IO::AIO;
189		165
190	use Carp ();	166	use Carp ();
191		167
192	no warnings;	168	use common::sense;
193	use strict 'vars';
194		169
195	use base 'Exporter';	170	use base 'Exporter';
196		171
197	BEGIN {	172	BEGIN {
198	our $VERSION = '3.19';	173	our $VERSION = '3.8';
199		174
200	our @AIO_REQ = qw(aio_sendfile aio_read aio_write aio_open aio_close	175	our @AIO_REQ = qw(aio_sendfile aio_read aio_write aio_open aio_close
201	aio_stat aio_lstat aio_unlink aio_rmdir aio_readdir	176	aio_stat aio_lstat aio_unlink aio_rmdir aio_readdir aio_readdirx
202	aio_scandir aio_symlink aio_readlink aio_sync aio_fsync	177	aio_scandir aio_symlink aio_readlink aio_sync aio_fsync
203	aio_fdatasync aio_sync_file_range aio_pathsync aio_readahead	178	aio_fdatasync aio_sync_file_range aio_pathsync aio_readahead
204	aio_rename aio_link aio_move aio_copy aio_group	179	aio_rename aio_link aio_move aio_copy aio_group
205	aio_nop aio_mknod aio_load aio_rmtree aio_mkdir aio_chown	180	aio_nop aio_mknod aio_load aio_rmtree aio_mkdir aio_chown
206	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);
207		184
208	our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice));	185	our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice));
209	our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush	186	our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush
210	min_parallel max_parallel max_idle	187	min_parallel max_parallel max_idle idle_timeout
211	nreqs nready npending nthreads	188	nreqs nready npending nthreads
212	max_poll_time max_poll_reqs);	189	max_poll_time max_poll_reqs
		190	sendfile fadvise madvise
		191	mmap munmap munlock munlockall);
213		192
214	push @AIO_REQ, qw(aio_busy); # not exported	193	push @AIO_REQ, qw(aio_busy); # not exported
215		194
216	@IO::AIO::GRP::ISA = 'IO::AIO::REQ';	195	@IO::AIO::GRP::ISA = 'IO::AIO::REQ';
217		196
218	require XSLoader;	197	require XSLoader;
219	XSLoader::load ("IO::AIO", $VERSION);	198	XSLoader::load ("IO::AIO", $VERSION);
220	}	199	}
221		200
222	=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::idle_timeout $seconds
		264	IO::AIO::max_outstanding $maxreqs
		265	IO::AIO::nreqs
		266	IO::AIO::nready
		267	IO::AIO::npending
		268
		269	IO::AIO::sendfile $ofh, $ifh, $offset, $count
		270	IO::AIO::fadvise $fh, $offset, $len, $advice
		271	IO::AIO::madvise $scalar, $offset, $length, $advice
		272	IO::AIO::mprotect $scalar, $offset, $length, $protect
		273	IO::AIO::munlock $scalar, $offset = 0, $length = undef
		274	IO::AIO::munlockall
223		275
224	=head2 AIO REQUEST FUNCTIONS	276	=head2 AIO REQUEST FUNCTIONS
225		277
226	All the C<aio_*> calls are more or less thin wrappers around the syscall	278	All the C<aio_*> calls are more or less thin wrappers around the syscall
227	with the same name (sans C<aio_>). The arguments are similar or identical,	279	with the same name (sans C<aio_>). The arguments are similar or identical,
…		…
307	by the umask in effect then the request is being executed, so better never	359	by the umask in effect then the request is being executed, so better never
308	change the umask.	360	change the umask.
309		361
310	Example:	362	Example:
311		363
312	aio_open "/etc/passwd", O_RDONLY, 0, sub {	364	aio_open "/etc/passwd", IO::AIO::O_RDONLY, 0, sub {
313	if ($_[0]) {	365	if ($_[0]) {
314	print "open successful, fh is $_[0]\n";	366	print "open successful, fh is $_[0]\n";
315	...	367	...
316	} else {	368	} else {
317	die "open failed: $!\n";	369	die "open failed: $!\n";
…		…
377	reading at byte offset C<$in_offset>, and starts writing at the current	429	reading at byte offset C<$in_offset>, and starts writing at the current
378	file offset of C<$out_fh>. Because of that, it is not safe to issue more	430	file offset of C<$out_fh>. Because of that, it is not safe to issue more
379	than one C<aio_sendfile> per C<$out_fh>, as they will interfere with each	431	than one C<aio_sendfile> per C<$out_fh>, as they will interfere with each
380	other.	432	other.
381		433
		434	Please note that C<aio_sendfile> can read more bytes from C<$in_fh> than
		435	are written, and there is no way to find out how many bytes have been read
		436	from C<aio_sendfile> alone, as C<aio_sendfile> only provides the number of
		437	bytes written to C<$out_fh>. Only if the result value equals C<$length>
		438	one can assume that C<$length> bytes have been read.
		439
		440	Unlike with other C<aio_> functions, it makes a lot of sense to use
		441	C<aio_sendfile> on non-blocking sockets, as long as one end (typically
		442	the C<$in_fh>) is a file - the file I/O will then be asynchronous, while
		443	the socket I/O will be non-blocking. Note, however, that you can run into
		444	a trap where C<aio_sendfile> reads some data with readahead, then fails
		445	to write all data, and when the socket is ready the next time, the data
		446	in the cache is already lost, forcing C<aio_sendfile> to again hit the
		447	disk. Explicit C<aio_read> + C<aio_write> let's you control resource usage
		448	much better.
		449
382	This call tries to make use of a native C<sendfile> syscall to provide	450	This call tries to make use of a native C<sendfile> syscall to provide
383	zero-copy operation. For this to work, C<$out_fh> should refer to a	451	zero-copy operation. For this to work, C<$out_fh> should refer to a
384	socket, and C<$in_fh> should refer to mmap'able file.	452	socket, and C<$in_fh> should refer to an mmap'able file.
385		453
386	If the native sendfile call fails or is not implemented, it will be	454	If a native sendfile cannot be found or it fails with C<ENOSYS>,
		455	C<ENOTSUP>, C<EOPNOTSUPP>, C<EAFNOSUPPORT>, C<EPROTOTYPE> or C<ENOTSOCK>,
387	emulated, so you can call C<aio_sendfile> on any type of filehandle	456	it will be emulated, so you can call C<aio_sendfile> on any type of
388	regardless of the limitations of the operating system.	457	filehandle regardless of the limitations of the operating system.
389
390	Please note, however, that C<aio_sendfile> can read more bytes from
391	C<$in_fh> than are written, and there is no way to find out how many
392	bytes have been read from C<aio_sendfile> alone, as C<aio_sendfile> only
393	provides the number of bytes written to C<$out_fh>. Only if the result
394	value equals C<$length> one can assume that C<$length> bytes have been
395	read.
396		458
397		459
398	=item aio_readahead $fh,$offset,$length, $callback->($retval)	460	=item aio_readahead $fh,$offset,$length, $callback->($retval)
399		461
400	C<aio_readahead> populates the page cache with data from a file so that	462	C<aio_readahead> populates the page cache with data from a file so that
…		…
423		485
424	Currently, the stats are always 64-bit-stats, i.e. instead of returning an	486	Currently, the stats are always 64-bit-stats, i.e. instead of returning an
425	error when stat'ing a large file, the results will be silently truncated	487	error when stat'ing a large file, the results will be silently truncated
426	unless perl itself is compiled with large file support.	488	unless perl itself is compiled with large file support.
427		489
		490	To help interpret the mode and dev/rdev stat values, IO::AIO offers the
		491	following constants and functions (if not implemented, the constants will
		492	be C<0> and the functions will either C<croak> or fall back on traditional
		493	behaviour).
		494
		495	C<S_IFMT>, C<S_IFIFO>, C<S_IFCHR>, C<S_IFBLK>, C<S_IFLNK>, C<S_IFREG>,
		496	C<S_IFDIR>, C<S_IFWHT>, C<S_IFSOCK>, C<IO::AIO::major $dev_t>,
		497	C<IO::AIO::minor $dev_t>, C<IO::AIO::makedev $major, $minor>.
		498
428	Example: Print the length of F</etc/passwd>:	499	Example: Print the length of F</etc/passwd>:
429		500
430	aio_stat "/etc/passwd", sub {	501	aio_stat "/etc/passwd", sub {
431	$_[0] and die "stat failed: $!";	502	$_[0] and die "stat failed: $!";
432	print "size is ", -s _, "\n";	503	print "size is ", -s _, "\n";
433	};	504	};
434		505
435		506
		507	=item aio_statvfs $fh_or_path, $callback->($statvfs)
		508
		509	Works like the POSIX C<statvfs> or C<fstatvfs> syscalls, depending on
		510	whether a file handle or path was passed.
		511
		512	On success, the callback is passed a hash reference with the following
		513	members: C<bsize>, C<frsize>, C<blocks>, C<bfree>, C<bavail>, C<files>,
		514	C<ffree>, C<favail>, C<fsid>, C<flag> and C<namemax>. On failure, C<undef>
		515	is passed.
		516
		517	The following POSIX IO::AIO::ST_* constants are defined: C<ST_RDONLY> and
		518	C<ST_NOSUID>.
		519
		520	The following non-POSIX IO::AIO::ST_* flag masks are defined to
		521	their correct value when available, or to C<0> on systems that do
		522	not support them: C<ST_NODEV>, C<ST_NOEXEC>, C<ST_SYNCHRONOUS>,
		523	C<ST_MANDLOCK>, C<ST_WRITE>, C<ST_APPEND>, C<ST_IMMUTABLE>, C<ST_NOATIME>,
		524	C<ST_NODIRATIME> and C<ST_RELATIME>.
		525
		526	Example: stat C</wd> and dump out the data if successful.
		527
		528	aio_statvfs "/wd", sub {
		529	my $f = $_[0]
		530	or die "statvfs: $!";
		531
		532	use Data::Dumper;
		533	say Dumper $f;
		534	};
		535
		536	# result:
		537	{
		538	bsize => 1024,
		539	bfree => 4333064312,
		540	blocks => 10253828096,
		541	files => 2050765568,
		542	flag => 4096,
		543	favail => 2042092649,
		544	bavail => 4333064312,
		545	ffree => 2042092649,
		546	namemax => 255,
		547	frsize => 1024,
		548	fsid => 1810
		549	}
		550
		551
436	=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status)	552	=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
437		553
438	Works like perl's C<utime> function (including the special case of $atime	554	Works like perl's C<utime> function (including the special case of $atime
439	and $mtime being undef). Fractional times are supported if the underlying	555	and $mtime being undef). Fractional times are supported if the underlying
440	syscalls support them.	556	syscalls support them.
…		…
488		604
489	The only (POSIX-) portable way of calling this function is:	605	The only (POSIX-) portable way of calling this function is:
490		606
491	aio_mknod $path, IO::AIO::S_IFIFO \| $mode, 0, sub { ...	607	aio_mknod $path, IO::AIO::S_IFIFO \| $mode, 0, sub { ...
492		608
		609	See C<aio_stat> for info about some potentially helpful extra constants
		610	and functions.
493		611
494	=item aio_link $srcpath, $dstpath, $callback->($status)	612	=item aio_link $srcpath, $dstpath, $callback->($status)
495		613
496	Asynchronously create a new link to the existing object at C<$srcpath> at	614	Asynchronously create a new link to the existing object at C<$srcpath> at
497	the path C<$dstpath> and call the callback with the result code.	615	the path C<$dstpath> and call the callback with the result code.
…		…
533		651
534	Unlike the POSIX call of the same name, C<aio_readdir> reads an entire	652	Unlike the POSIX call of the same name, C<aio_readdir> reads an entire
535	directory (i.e. opendir + readdir + closedir). The entries will not be	653	directory (i.e. opendir + readdir + closedir). The entries will not be
536	sorted, and will B<NOT> include the C<.> and C<..> entries.	654	sorted, and will B<NOT> include the C<.> and C<..> entries.
537		655
538	The callback a single argument which is either C<undef> or an array-ref	656	The callback is passed a single argument which is either C<undef> or an
539	with the filenames.	657	array-ref with the filenames.
		658
		659
		660	=item aio_readdirx $pathname, $flags, $callback->($entries, $flags)
		661
		662	Quite similar to C<aio_readdir>, but the C<$flags> argument allows to tune
		663	behaviour and output format. In case of an error, C<$entries> will be
		664	C<undef>.
		665
		666	The flags are a combination of the following constants, ORed together (the
		667	flags will also be passed to the callback, possibly modified):
		668
		669	=over 4
		670
		671	=item IO::AIO::READDIR_DENTS
		672
		673	When this flag is off, then the callback gets an arrayref with of names
		674	only (as with C<aio_readdir>), otherwise it gets an arrayref with
		675	C<[$name, $type, $inode]> arrayrefs, each describing a single directory
		676	entry in more detail.
		677
		678	C<$name> is the name of the entry.
		679
		680	C<$type> is one of the C<IO::AIO::DT_xxx> constants:
		681
		682	C<IO::AIO::DT_UNKNOWN>, C<IO::AIO::DT_FIFO>, C<IO::AIO::DT_CHR>, C<IO::AIO::DT_DIR>,
		683	C<IO::AIO::DT_BLK>, C<IO::AIO::DT_REG>, C<IO::AIO::DT_LNK>, C<IO::AIO::DT_SOCK>,
		684	C<IO::AIO::DT_WHT>.
		685
		686	C<IO::AIO::DT_UNKNOWN> means just that: readdir does not know. If you need to
		687	know, you have to run stat yourself. Also, for speed reasons, the C<$type>
		688	scalars are read-only: you can not modify them.
		689
		690	C<$inode> is the inode number (which might not be exact on systems with 64
		691	bit inode numbers and 32 bit perls). This field has unspecified content on
		692	systems that do not deliver the inode information.
		693
		694	=item IO::AIO::READDIR_DIRS_FIRST
		695
		696	When this flag is set, then the names will be returned in an order where
		697	likely directories come first. This is useful when you need to quickly
		698	find directories, or you want to find all directories while avoiding to
		699	stat() each entry.
		700
		701	If the system returns type information in readdir, then this is used
		702	to find directories directly. Otherwise, likely directories are files
		703	beginning with ".", or otherwise files with no dots, of which files with
		704	short names are tried first.
		705
		706	=item IO::AIO::READDIR_STAT_ORDER
		707
		708	When this flag is set, then the names will be returned in an order
		709	suitable for stat()'ing each one. That is, when you plan to stat()
		710	all files in the given directory, then the returned order will likely
		711	be fastest.
		712
		713	If both this flag and C<IO::AIO::READDIR_DIRS_FIRST> are specified, then
		714	the likely dirs come first, resulting in a less optimal stat order.
		715
		716	=item IO::AIO::READDIR_FOUND_UNKNOWN
		717
		718	This flag should not be set when calling C<aio_readdirx>. Instead, it
		719	is being set by C<aio_readdirx>, when any of the C<$type>'s found were
		720	C<IO::AIO::DT_UNKNOWN>. The absense of this flag therefore indicates that all
		721	C<$type>'s are known, which can be used to speed up some algorithms.
		722
		723	=back
540		724
541		725
542	=item aio_load $path, $data, $callback->($status)	726	=item aio_load $path, $data, $callback->($status)
543		727
544	This is a composite request that tries to fully load the given file into	728	This is a composite request that tries to fully load the given file into
…		…
569		753
570	=item aio_copy $srcpath, $dstpath, $callback->($status)	754	=item aio_copy $srcpath, $dstpath, $callback->($status)
571		755
572	Try to copy the I<file> (directories not supported as either source or	756	Try to copy the I<file> (directories not supported as either source or
573	destination) from C<$srcpath> to C<$dstpath> and call the callback with	757	destination) from C<$srcpath> to C<$dstpath> and call the callback with
574	the C<0> (error) or C<-1> ok.	758	a status of C<0> (ok) or C<-1> (error, see C<$!>).
575		759
576	This is a composite request that creates the destination file with	760	This is a composite request that creates the destination file with
577	mode 0200 and copies the contents of the source file into it using	761	mode 0200 and copies the contents of the source file into it using
578	C<aio_sendfile>, followed by restoring atime, mtime, access mode and	762	C<aio_sendfile>, followed by restoring atime, mtime, access mode and
579	uid/gid, in that order.	763	uid/gid, in that order.
…		…
591	my $grp = aio_group $cb;	775	my $grp = aio_group $cb;
592		776
593	aioreq_pri $pri;	777	aioreq_pri $pri;
594	add $grp aio_open $src, O_RDONLY, 0, sub {	778	add $grp aio_open $src, O_RDONLY, 0, sub {
595	if (my $src_fh = $_[0]) {	779	if (my $src_fh = $_[0]) {
596	my @stat = stat $src_fh;	780	my @stat = stat $src_fh; # hmm, might block over nfs?
597		781
598	aioreq_pri $pri;	782	aioreq_pri $pri;
599	add $grp aio_open $dst, O_CREAT \| O_WRONLY \| O_TRUNC, 0200, sub {	783	add $grp aio_open $dst, O_CREAT \| O_WRONLY \| O_TRUNC, 0200, sub {
600	if (my $dst_fh = $_[0]) {	784	if (my $dst_fh = $_[0]) {
601	aioreq_pri $pri;	785	aioreq_pri $pri;
602	add $grp aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub {	786	add $grp aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub {
603	if ($_[0] == $stat[7]) {	787	if ($_[0] == $stat[7]) {
604	$grp->result (0);	788	$grp->result (0);
605	close $src_fh;	789	close $src_fh;
606		790
607	# those should not normally block. should. should.	791	my $ch = sub {
608	utime $stat[8], $stat[9], $dst;	792	aioreq_pri $pri;
609	chmod $stat[2] & 07777, $dst_fh;	793	add $grp aio_chmod $dst_fh, $stat[2] & 07777, sub {
610	chown $stat[4], $stat[5], $dst_fh;	794	aioreq_pri $pri;
		795	add $grp aio_chown $dst_fh, $stat[4], $stat[5], sub {
		796	aioreq_pri $pri;
		797	add $grp aio_close $dst_fh;
		798	}
		799	};
		800	};
611		801
612	aioreq_pri $pri;	802	aioreq_pri $pri;
613	add $grp aio_close $dst_fh;	803	add $grp aio_utime $dst_fh, $stat[8], $stat[9], sub {
		804	if ($_[0] < 0 && $! == ENOSYS) {
		805	aioreq_pri $pri;
		806	add $grp aio_utime $dst, $stat[8], $stat[9], $ch;
		807	} else {
		808	$ch->();
		809	}
		810	};
614	} else {	811	} else {
615	$grp->result (-1);	812	$grp->result (-1);
616	close $src_fh;	813	close $src_fh;
617	close $dst_fh;	814	close $dst_fh;
618		815
…		…
635		832
636	=item aio_move $srcpath, $dstpath, $callback->($status)	833	=item aio_move $srcpath, $dstpath, $callback->($status)
637		834
638	Try to move the I<file> (directories not supported as either source or	835	Try to move the I<file> (directories not supported as either source or
639	destination) from C<$srcpath> to C<$dstpath> and call the callback with	836	destination) from C<$srcpath> to C<$dstpath> and call the callback with
640	the C<0> (error) or C<-1> ok.	837	a status of C<0> (ok) or C<-1> (error, see C<$!>).
641		838
642	This is a composite request that tries to rename(2) the file first; if	839	This is a composite request that tries to rename(2) the file first; if
643	rename fails with C<EXDEV>, it copies the file with C<aio_copy> and, if	840	rename fails with C<EXDEV>, it copies the file with C<aio_copy> and, if
644	that is successful, unlinks the C<$srcpath>.	841	that is successful, unlinks the C<$srcpath>.
645		842
…		…
696		893
697	Implementation notes.	894	Implementation notes.
698		895
699	The C<aio_readdir> cannot be avoided, but C<stat()>'ing every entry can.	896	The C<aio_readdir> cannot be avoided, but C<stat()>'ing every entry can.
700		897
		898	If readdir returns file type information, then this is used directly to
		899	find directories.
		900
701	After reading the directory, the modification time, size etc. of the	901	Otherwise, after reading the directory, the modification time, size etc.
702	directory before and after the readdir is checked, and if they match (and	902	of the directory before and after the readdir is checked, and if they
703	isn't the current time), the link count will be used to decide how many	903	match (and isn't the current time), the link count will be used to decide
704	entries are directories (if >= 2). Otherwise, no knowledge of the number	904	how many entries are directories (if >= 2). Otherwise, no knowledge of the
705	of subdirectories will be assumed.	905	number of subdirectories will be assumed.
706		906
707	Then entries will be sorted into likely directories (everything without	907	Then entries will be sorted into likely directories a non-initial dot
708	a non-initial dot currently) and likely non-directories (everything	908	currently) and likely non-directories (see C<aio_readdirx>). Then every
709	else). Then every entry plus an appended C</.> will be C<stat>'ed,	909	entry plus an appended C</.> will be C<stat>'ed, likely directories first,
710	likely directories first. If that succeeds, it assumes that the entry	910	in order of their inode numbers. If that succeeds, it assumes that the
711	is a directory or a symlink to directory (which will be checked	911	entry is a directory or a symlink to directory (which will be checked
712	seperately). This is often faster than stat'ing the entry itself because	912	seperately). This is often faster than stat'ing the entry itself because
713	filesystems might detect the type of the entry without reading the inode	913	filesystems might detect the type of the entry without reading the inode
714	data (e.g. ext2fs filetype feature).	914	data (e.g. ext2fs filetype feature), even on systems that cannot return
		915	the filetype information on readdir.
715		916
716	If the known number of directories (link count - 2) has been reached, the	917	If the known number of directories (link count - 2) has been reached, the
717	rest of the entries is assumed to be non-directories.	918	rest of the entries is assumed to be non-directories.
718		919
719	This only works with certainty on POSIX (= UNIX) filesystems, which	920	This only works with certainty on POSIX (= UNIX) filesystems, which
…		…
741	my $now = time;	942	my $now = time;
742	my $hash1 = join ":", (stat _)[0,1,3,7,9];	943	my $hash1 = join ":", (stat _)[0,1,3,7,9];
743		944
744	# read the directory entries	945	# read the directory entries
745	aioreq_pri $pri;	946	aioreq_pri $pri;
746	add $grp aio_readdir $path, sub {	947	add $grp aio_readdirx $path, READDIR_DIRS_FIRST, sub {
747	my $entries = shift	948	my $entries = shift
748	or return $grp->result ();	949	or return $grp->result ();
749		950
750	# stat the dir another time	951	# stat the dir another time
751	aioreq_pri $pri;	952	aioreq_pri $pri;
…		…
757	# take the slow route if anything looks fishy	958	# take the slow route if anything looks fishy
758	if ($hash1 ne $hash2 or (stat _)[9] == $now) {	959	if ($hash1 ne $hash2 or (stat _)[9] == $now) {
759	$ndirs = -1;	960	$ndirs = -1;
760	} else {	961	} else {
761	# if nlink == 2, we are finished	962	# if nlink == 2, we are finished
762	# on non-posix-fs's, we rely on nlink < 2	963	# for non-posix-fs's, we rely on nlink < 2
763	$ndirs = (stat _)[3] - 2	964	$ndirs = (stat _)[3] - 2
764	or return $grp->result ([], $entries);	965	or return $grp->result ([], $entries);
765	}	966	}
766		967
767	# sort into likely dirs and likely nondirs
768	# dirs == files without ".", short entries first
769	$entries = [map $_->[0],
770	sort { $b->[1] cmp $a->[1] }
771	map [$_, sprintf "%s%04d", (/.\./ ? "1" : "0"), length],
772	@$entries];
773
774	my (@dirs, @nondirs);	968	my (@dirs, @nondirs);
775		969
776	my $statgrp = add $grp aio_group sub {	970	my $statgrp = add $grp aio_group sub {
777	$grp->result (\@dirs, \@nondirs);	971	$grp->result (\@dirs, \@nondirs);
778	};	972	};
779		973
780	limit $statgrp $maxreq;	974	limit $statgrp $maxreq;
781	feed $statgrp sub {	975	feed $statgrp sub {
782	return unless @$entries;	976	return unless @$entries;
783	my $entry = pop @$entries;	977	my $entry = shift @$entries;
784		978
785	aioreq_pri $pri;	979	aioreq_pri $pri;
786	add $statgrp aio_stat "$path/$entry/.", sub {	980	add $statgrp aio_stat "$path/$entry/.", sub {
787	if ($_[0] < 0) {	981	if ($_[0] < 0) {
788	push @nondirs, $entry;	982	push @nondirs, $entry;
…		…
882	(E.g. rename). This might not work on all operating systems or have any	1076	(E.g. rename). This might not work on all operating systems or have any
883	specific effect, but usually it makes sure that directory changes get	1077	specific effect, but usually it makes sure that directory changes get
884	written to disc. It works for anything that can be opened for read-only,	1078	written to disc. It works for anything that can be opened for read-only,
885	not just directories.	1079	not just directories.
886		1080
		1081	Future versions of this function might fall back to other methods when
		1082	C<fsync> on the directory fails (such as calling C<sync>).
		1083
887	Passes C<0> when everything went ok, and C<-1> on error.	1084	Passes C<0> when everything went ok, and C<-1> on error.
888		1085
889	=cut	1086	=cut
890		1087
891	sub aio_pathsync($;$) {	1088	sub aio_pathsync($;$) {
…		…
911	};	1108	};
912		1109
913	$grp	1110	$grp
914	}	1111	}
915		1112
		1113	=item aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
		1114
		1115	This is a rather advanced IO::AIO call, which only works on mmap(2)ed
		1116	scalars (see the C<IO::AIO::mmap> function, although it also works on data
		1117	scalars managed by the L<Sys::Mmap> or L<Mmap> modules, note that the
		1118	scalar must only be modified in-place while an aio operation is pending on
		1119	it).
		1120
		1121	It calls the C<msync> function of your OS, if available, with the memory
		1122	area starting at C<$offset> in the string and ending C<$length> bytes
		1123	later. If C<$length> is negative, counts from the end, and if C<$length>
		1124	is C<undef>, then it goes till the end of the string. The flags can be
		1125	a combination of C<IO::AIO::MS_ASYNC>, C<IO::AIO::MS_INVALIDATE> and
		1126	C<IO::AIO::MS_SYNC>.
		1127
		1128	=item aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
		1129
		1130	This is a rather advanced IO::AIO call, which works best on mmap(2)ed
		1131	scalars.
		1132
		1133	It touches (reads or writes) all memory pages in the specified
		1134	range inside the scalar. All caveats and parameters are the same
		1135	as for C<aio_msync>, above, except for flags, which must be either
		1136	C<0> (which reads all pages and ensures they are instantiated) or
		1137	C<IO::AIO::MT_MODIFY>, which modifies the memory page s(by reading and
		1138	writing an octet from it, which dirties the page).
		1139
		1140	=item aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status)
		1141
		1142	This is a rather advanced IO::AIO call, which works best on mmap(2)ed
		1143	scalars.
		1144
		1145	It reads in all the pages of the underlying storage into memory (if any)
		1146	and locks them, so they are not getting swapped/paged out or removed.
		1147
		1148	If C<$length> is undefined, then the scalar will be locked till the end.
		1149
		1150	On systems that do not implement C<mlock>, this function returns C<-1>
		1151	and sets errno to C<ENOSYS>.
		1152
		1153	Note that the corresponding C<munlock> is synchronous and is
		1154	documented under L<MISCELLANEOUS FUNCTIONS>.
		1155
		1156	Example: open a file, mmap and mlock it - both will be undone when
		1157	C<$data> gets destroyed.
		1158
		1159	open my $fh, "<", $path or die "$path: $!";
		1160	my $data;
		1161	IO::AIO::mmap $data, -s $fh, IO::AIO::PROT_READ, IO::AIO::MAP_SHARED, $fh;
		1162	aio_mlock $data; # mlock in background
		1163
		1164	=item aio_mlockall $flags, $callback->($status)
		1165
		1166	Calls the C<mlockall> function with the given C<$flags> (a combination of
		1167	C<IO::AIO::MCL_CURRENT> and C<IO::AIO::MCL_FUTURE>).
		1168
		1169	On systems that do not implement C<mlockall>, this function returns C<-1>
		1170	and sets errno to C<ENOSYS>.
		1171
		1172	Note that the corresponding C<munlockall> is synchronous and is
		1173	documented under L<MISCELLANEOUS FUNCTIONS>.
		1174
		1175	Example: asynchronously lock all current and future pages into memory.
		1176
		1177	aio_mlockall IO::AIO::MCL_FUTURE;
		1178
916	=item aio_group $callback->(...)	1179	=item aio_group $callback->(...)
917		1180
918	This is a very special aio request: Instead of doing something, it is a	1181	This is a very special aio request: Instead of doing something, it is a
919	container for other aio requests, which is useful if you want to bundle	1182	container for other aio requests, which is useful if you want to bundle
920	many requests into a single, composite, request with a definite callback	1183	many requests into a single, composite, request with a definite callback
…		…
969	=item cancel $req	1232	=item cancel $req
970		1233
971	Cancels the request, if possible. Has the effect of skipping execution	1234	Cancels the request, if possible. Has the effect of skipping execution
972	when entering the B<execute> state and skipping calling the callback when	1235	when entering the B<execute> state and skipping calling the callback when
973	entering the the B<result> state, but will leave the request otherwise	1236	entering the the B<result> state, but will leave the request otherwise
974	untouched. That means that requests that currently execute will not be	1237	untouched (with the exception of readdir). That means that requests that
975	stopped and resources held by the request will not be freed prematurely.	1238	currently execute will not be stopped and resources held by the request
		1239	will not be freed prematurely.
976		1240
977	=item cb $req $callback->(...)	1241	=item cb $req $callback->(...)
978		1242
979	Replace (or simply set) the callback registered to the request.	1243	Replace (or simply set) the callback registered to the request.
980		1244
…		…
1053		1317
1054	=item $grp->cancel_subs	1318	=item $grp->cancel_subs
1055		1319
1056	Cancel all subrequests and clears any feeder, but not the group request	1320	Cancel all subrequests and clears any feeder, but not the group request
1057	itself. Useful when you queued a lot of events but got a result early.	1321	itself. Useful when you queued a lot of events but got a result early.
		1322
		1323	The group request will finish normally (you cannot add requests to the
		1324	group).
1058		1325
1059	=item $grp->result (...)	1326	=item $grp->result (...)
1060		1327
1061	Set the result value(s) that will be passed to the group callback when all	1328	Set the result value(s) that will be passed to the group callback when all
1062	subrequests have finished and set the groups errno to the current value	1329	subrequests have finished and set the groups errno to the current value
…		…
1131	=over 4	1398	=over 4
1132		1399
1133	=item $fileno = IO::AIO::poll_fileno	1400	=item $fileno = IO::AIO::poll_fileno
1134		1401
1135	Return the I<request result pipe file descriptor>. This filehandle must be	1402	Return the I<request result pipe file descriptor>. This filehandle must be
1136	polled for reading by some mechanism outside this module (e.g. Event or	1403	polled for reading by some mechanism outside this module (e.g. EV, Glib,
1137	select, see below or the SYNOPSIS). If the pipe becomes readable you have	1404	select and so on, see below or the SYNOPSIS). If the pipe becomes readable
1138	to call C<poll_cb> to check the results.	1405	you have to call C<poll_cb> to check the results.
1139		1406
1140	See C<poll_cb> for an example.	1407	See C<poll_cb> for an example.
1141		1408
1142	=item IO::AIO::poll_cb	1409	=item IO::AIO::poll_cb
1143		1410
…		…
1150	If not all requests were processed for whatever reason, the filehandle	1417	If not all requests were processed for whatever reason, the filehandle
1151	will still be ready when C<poll_cb> returns, so normally you don't have to	1418	will still be ready when C<poll_cb> returns, so normally you don't have to
1152	do anything special to have it called later.	1419	do anything special to have it called later.
1153		1420
1154	Example: Install an Event watcher that automatically calls	1421	Example: Install an Event watcher that automatically calls
1155	IO::AIO::poll_cb with high priority:	1422	IO::AIO::poll_cb with high priority (more examples can be found in the
		1423	SYNOPSIS section, at the top of this document):
1156		1424
1157	Event->io (fd => IO::AIO::poll_fileno,	1425	Event->io (fd => IO::AIO::poll_fileno,
1158	poll => 'r', async => 1,	1426	poll => 'r', async => 1,
1159	cb => \&IO::AIO::poll_cb);	1427	cb => \&IO::AIO::poll_cb);
		1428
		1429	=item IO::AIO::poll_wait
		1430
		1431	If there are any outstanding requests and none of them in the result
		1432	phase, wait till the result filehandle becomes ready for reading (simply
		1433	does a C<select> on the filehandle. This is useful if you want to
		1434	synchronously wait for some requests to finish).
		1435
		1436	See C<nreqs> for an example.
		1437
		1438	=item IO::AIO::poll
		1439
		1440	Waits until some requests have been handled.
		1441
		1442	Returns the number of requests processed, but is otherwise strictly
		1443	equivalent to:
		1444
		1445	IO::AIO::poll_wait, IO::AIO::poll_cb
		1446
		1447	=item IO::AIO::flush
		1448
		1449	Wait till all outstanding AIO requests have been handled.
		1450
		1451	Strictly equivalent to:
		1452
		1453	IO::AIO::poll_wait, IO::AIO::poll_cb
		1454	while IO::AIO::nreqs;
1160		1455
1161	=item IO::AIO::max_poll_reqs $nreqs	1456	=item IO::AIO::max_poll_reqs $nreqs
1162		1457
1163	=item IO::AIO::max_poll_time $seconds	1458	=item IO::AIO::max_poll_time $seconds
1164		1459
…		…
1189	# use a low priority so other tasks have priority	1484	# use a low priority so other tasks have priority
1190	Event->io (fd => IO::AIO::poll_fileno,	1485	Event->io (fd => IO::AIO::poll_fileno,
1191	poll => 'r', nice => 1,	1486	poll => 'r', nice => 1,
1192	cb => &IO::AIO::poll_cb);	1487	cb => &IO::AIO::poll_cb);
1193		1488
1194	=item IO::AIO::poll_wait
1195
1196	If there are any outstanding requests and none of them in the result
1197	phase, wait till the result filehandle becomes ready for reading (simply
1198	does a C<select> on the filehandle. This is useful if you want to
1199	synchronously wait for some requests to finish).
1200
1201	See C<nreqs> for an example.
1202
1203	=item IO::AIO::poll
1204
1205	Waits until some requests have been handled.
1206
1207	Returns the number of requests processed, but is otherwise strictly
1208	equivalent to:
1209
1210	IO::AIO::poll_wait, IO::AIO::poll_cb
1211
1212	=item IO::AIO::flush
1213
1214	Wait till all outstanding AIO requests have been handled.
1215
1216	Strictly equivalent to:
1217
1218	IO::AIO::poll_wait, IO::AIO::poll_cb
1219	while IO::AIO::nreqs;
1220
1221	=back	1489	=back
1222		1490
1223	=head3 CONTROLLING THE NUMBER OF THREADS	1491	=head3 CONTROLLING THE NUMBER OF THREADS
1224		1492
1225	=over	1493	=over
…		…
1258		1526
1259	Under normal circumstances you don't need to call this function.	1527	Under normal circumstances you don't need to call this function.
1260		1528
1261	=item IO::AIO::max_idle $nthreads	1529	=item IO::AIO::max_idle $nthreads
1262		1530
1263	Limit the number of threads (default: 4) that are allowed to idle (i.e.,	1531	Limit the number of threads (default: 4) that are allowed to idle
1264	threads that did not get a request to process within 10 seconds). That	1532	(i.e., threads that did not get a request to process within the idle
1265	means if a thread becomes idle while C<$nthreads> other threads are also	1533	timeout (default: 10 seconds). That means if a thread becomes idle while
1266	idle, it will free its resources and exit.	1534	C<$nthreads> other threads are also idle, it will free its resources and
		1535	exit.
1267		1536
1268	This is useful when you allow a large number of threads (e.g. 100 or 1000)	1537	This is useful when you allow a large number of threads (e.g. 100 or 1000)
1269	to allow for extremely high load situations, but want to free resources	1538	to allow for extremely high load situations, but want to free resources
1270	under normal circumstances (1000 threads can easily consume 30MB of RAM).	1539	under normal circumstances (1000 threads can easily consume 30MB of RAM).
1271		1540
1272	The default is probably ok in most situations, especially if thread	1541	The default is probably ok in most situations, especially if thread
1273	creation is fast. If thread creation is very slow on your system you might	1542	creation is fast. If thread creation is very slow on your system you might
1274	want to use larger values.	1543	want to use larger values.
		1544
		1545	=item IO::AIO::idle_timeout $seconds
		1546
		1547	Sets the minimum idle timeout (default 10) after which worker threads are
		1548	allowed to exit. SEe C<IO::AIO::max_idle>.
1275		1549
1276	=item IO::AIO::max_outstanding $maxreqs	1550	=item IO::AIO::max_outstanding $maxreqs
1277		1551
1278	This is a very bad function to use in interactive programs because it	1552	This is a very bad function to use in interactive programs because it
1279	blocks, and a bad way to reduce concurrency because it is inexact: Better	1553	blocks, and a bad way to reduce concurrency because it is inexact: Better
…		…
1317	Returns the number of requests currently in the pending state (executed,	1591	Returns the number of requests currently in the pending state (executed,
1318	but not yet processed by poll_cb).	1592	but not yet processed by poll_cb).
1319		1593
1320	=back	1594	=back
1321		1595
		1596	=head3 MISCELLANEOUS FUNCTIONS
		1597
		1598	IO::AIO implements some functions that might be useful, but are not
		1599	asynchronous.
		1600
		1601	=over 4
		1602
		1603	=item IO::AIO::sendfile $ofh, $ifh, $offset, $count
		1604
		1605	Calls the C<eio_sendfile_sync> function, which is like C<aio_sendfile>,
		1606	but is blocking (this makes most sense if you know the input data is
		1607	likely cached already and the output filehandle is set to non-blocking
		1608	operations).
		1609
		1610	Returns the number of bytes copied, or C<-1> on error.
		1611
		1612	=item IO::AIO::fadvise $fh, $offset, $len, $advice
		1613
		1614	Simply calls the C<posix_fadvise> function (see its
		1615	manpage for details). The following advice constants are
		1616	avaiable: C<IO::AIO::FADV_NORMAL>, C<IO::AIO::FADV_SEQUENTIAL>,
		1617	C<IO::AIO::FADV_RANDOM>, C<IO::AIO::FADV_NOREUSE>,
		1618	C<IO::AIO::FADV_WILLNEED>, C<IO::AIO::FADV_DONTNEED>.
		1619
		1620	On systems that do not implement C<posix_fadvise>, this function returns
		1621	ENOSYS, otherwise the return value of C<posix_fadvise>.
		1622
		1623	=item IO::AIO::madvise $scalar, $offset, $len, $advice
		1624
		1625	Simply calls the C<posix_madvise> function (see its
		1626	manpage for details). The following advice constants are
		1627	avaiable: C<IO::AIO::MADV_NORMAL>, C<IO::AIO::MADV_SEQUENTIAL>,
		1628	C<IO::AIO::MADV_RANDOM>, C<IO::AIO::MADV_WILLNEED>, C<IO::AIO::MADV_DONTNEED>.
		1629
		1630	On systems that do not implement C<posix_madvise>, this function returns
		1631	ENOSYS, otherwise the return value of C<posix_madvise>.
		1632
		1633	=item IO::AIO::mprotect $scalar, $offset, $len, $protect
		1634
		1635	Simply calls the C<mprotect> function on the preferably AIO::mmap'ed
		1636	$scalar (see its manpage for details). The following protect
		1637	constants are avaiable: C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_READ>,
		1638	C<IO::AIO::PROT_WRITE>, C<IO::AIO::PROT_EXEC>.
		1639
		1640	On systems that do not implement C<mprotect>, this function returns
		1641	ENOSYS, otherwise the return value of C<mprotect>.
		1642
		1643	=item IO::AIO::mmap $scalar, $length, $prot, $flags, $fh[, $offset]
		1644
		1645	Memory-maps a file (or anonymous memory range) and attaches it to the
		1646	given C<$scalar>, which will act like a string scalar.
		1647
		1648	The only operations allowed on the scalar are C<substr>/C<vec> that don't
		1649	change the string length, and most read-only operations such as copying it
		1650	or searching it with regexes and so on.
		1651
		1652	Anything else is unsafe and will, at best, result in memory leaks.
		1653
		1654	The memory map associated with the C<$scalar> is automatically removed
		1655	when the C<$scalar> is destroyed, or when the C<IO::AIO::mmap> or
		1656	C<IO::AIO::munmap> functions are called.
		1657
		1658	This calls the C<mmap>(2) function internally. See your system's manual
		1659	page for details on the C<$length>, C<$prot> and C<$flags> parameters.
		1660
		1661	The C<$length> must be larger than zero and smaller than the actual
		1662	filesize.
		1663
		1664	C<$prot> is a combination of C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_EXEC>,
		1665	C<IO::AIO::PROT_READ> and/or C<IO::AIO::PROT_WRITE>,
		1666
		1667	C<$flags> can be a combination of C<IO::AIO::MAP_SHARED> or
		1668	C<IO::AIO::MAP_PRIVATE>, or a number of system-specific flags (when
		1669	not available, the are defined as 0): C<IO::AIO::MAP_ANONYMOUS>
		1670	(which is set to C<MAP_ANON> if your system only provides this
		1671	constant), C<IO::AIO::MAP_HUGETLB>, C<IO::AIO::MAP_LOCKED>,
		1672	C<IO::AIO::MAP_NORESERVE>, C<IO::AIO::MAP_POPULATE> or
		1673	C<IO::AIO::MAP_NONBLOCK>
		1674
		1675	If C<$fh> is C<undef>, then a file descriptor of C<-1> is passed.
		1676
		1677	C<$offset> is the offset from the start of the file - it generally must be
		1678	a multiple of C<IO::AIO::PAGESIZE> and defaults to C<0>.
		1679
		1680	Example:
		1681
		1682	use Digest::MD5;
		1683	use IO::AIO;
		1684
		1685	open my $fh, "<verybigfile"
		1686	or die "$!";
		1687
		1688	IO::AIO::mmap my $data, -s $fh, IO::AIO::PROT_READ, IO::AIO::MAP_SHARED, $fh
		1689	or die "verybigfile: $!";
		1690
		1691	my $fast_md5 = md5 $data;
		1692
		1693	=item IO::AIO::munmap $scalar
		1694
		1695	Removes a previous mmap and undefines the C<$scalar>.
		1696
		1697	=item IO::AIO::munlock $scalar, $offset = 0, $length = undef
		1698
		1699	Calls the C<munlock> function, undoing the effects of a previous
		1700	C<aio_mlock> call (see its description for details).
		1701
		1702	=item IO::AIO::munlockall
		1703
		1704	Calls the C<munlockall> function.
		1705
		1706	On systems that do not implement C<munlockall>, this function returns
		1707	ENOSYS, otherwise the return value of C<munlockall>.
		1708
		1709	=back
		1710
1322	=cut	1711	=cut
1323		1712
1324	min_parallel 8;	1713	min_parallel 8;
1325		1714
1326	END { flush }	1715	END { flush }
1327		1716
1328	1;	1717	1;
		1718
		1719	=head1 EVENT LOOP INTEGRATION
		1720
		1721	It is recommended to use L<AnyEvent::AIO> to integrate IO::AIO
		1722	automatically into many event loops:
		1723
		1724	# AnyEvent integration (EV, Event, Glib, Tk, POE, urxvt, pureperl...)
		1725	use AnyEvent::AIO;
		1726
		1727	You can also integrate IO::AIO manually into many event loops, here are
		1728	some examples of how to do this:
		1729
		1730	# EV integration
		1731	my $aio_w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb;
		1732
		1733	# Event integration
		1734	Event->io (fd => IO::AIO::poll_fileno,
		1735	poll => 'r',
		1736	cb => \&IO::AIO::poll_cb);
		1737
		1738	# Glib/Gtk2 integration
		1739	add_watch Glib::IO IO::AIO::poll_fileno,
		1740	in => sub { IO::AIO::poll_cb; 1 };
		1741
		1742	# Tk integration
		1743	Tk::Event::IO->fileevent (IO::AIO::poll_fileno, "",
		1744	readable => \&IO::AIO::poll_cb);
		1745
		1746	# Danga::Socket integration
		1747	Danga::Socket->AddOtherFds (IO::AIO::poll_fileno =>
		1748	\&IO::AIO::poll_cb);
1329		1749
1330	=head2 FORK BEHAVIOUR	1750	=head2 FORK BEHAVIOUR
1331		1751
1332	This module should do "the right thing" when the process using it forks:	1752	This module should do "the right thing" when the process using it forks:
1333		1753

Diff Legend

-–
+Removed lines
-+
+Added lines
-<
+Changed lines
->
+Changed lines

Comparing IO-AIO/AIO.pm (file contents): Revision 1.146 by root, Tue Apr 21 20:06:05 2009 UTC vs. Revision 1.189 by root, Sun Mar 27 10:26:08 2011 UTC

Diff Legend

Comparing IO-AIO/AIO.pm (file contents):
Revision 1.146 by root, Tue Apr 21 20:06:05 2009 UTC vs.
Revision 1.189 by root, Sun Mar 27 10:26:08 2011 UTC