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

Comparing IO-AIO/AIO.pm (file contents):
Revision 1.171 by root, Sat Jan 2 14:24:32 2010 UTC vs.
Revision 1.206 by root, Sun Jul 24 03:32:51 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
…		…
25	my $req = aio_unlink "/tmp/file", sub { };	25	my $req = aio_unlink "/tmp/file", sub { };
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
31	# AnyEvent integration (EV, Event, Glib, Tk, POE, urxvt, pureperl...)
32	use AnyEvent::AIO;
33
34	# EV integration
35	my $aio_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		30
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. It is implemented as an interface to C<libeio>	34	operating system supports. It is implemented as an interface to C<libeio>
…		…
99		76
100	# register the IO::AIO callback with EV	77	# register the IO::AIO callback with EV
101	my $aio_w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb;	78	my $aio_w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb;
102		79
103	# queue the request to open /etc/passwd	80	# queue the request to open /etc/passwd
104	aio_open "/etc/passwd", O_RDONLY, 0, sub {	81	aio_open "/etc/passwd", IO::AIO::O_RDONLY, 0, sub {
105	my $fh = shift	82	my $fh = shift
106	or die "error while opening: $!";	83	or die "error while opening: $!";
107		84
108	# stat'ing filehandles is generally non-blocking	85	# stat'ing filehandles is generally non-blocking
109	my $size = -s $fh;	86	my $size = -s $fh;
…		…
191	use common::sense;	168	use common::sense;
192		169
193	use base 'Exporter';	170	use base 'Exporter';
194		171
195	BEGIN {	172	BEGIN {
196	our $VERSION = '3.4';	173	our $VERSION = '4.0';
197		174
198	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
199	aio_stat aio_lstat aio_unlink aio_rmdir aio_readdir aio_readdirx	176	aio_stat aio_lstat aio_unlink aio_rmdir aio_readdir aio_readdirx
200	aio_scandir aio_symlink aio_readlink aio_sync aio_fsync	177	aio_scandir aio_symlink aio_readlink aio_realpath aio_sync
201	aio_fdatasync aio_sync_file_range aio_pathsync aio_readahead	178	aio_fsync aio_syncfs aio_fdatasync aio_sync_file_range aio_fallocate
		179	aio_pathsync aio_readahead
202	aio_rename aio_link aio_move aio_copy aio_group	180	aio_rename aio_link aio_move aio_copy aio_group
203	aio_nop aio_mknod aio_load aio_rmtree aio_mkdir aio_chown	181	aio_nop aio_mknod aio_load aio_rmtree aio_mkdir aio_chown
204	aio_chmod aio_utime aio_truncate	182	aio_chmod aio_utime aio_truncate
		183	aio_msync aio_mtouch aio_mlock aio_mlockall
205	aio_msync aio_mtouch);	184	aio_statvfs);
206		185
207	our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice));	186	our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice));
208	our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush	187	our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush
209	min_parallel max_parallel max_idle	188	min_parallel max_parallel max_idle idle_timeout
210	nreqs nready npending nthreads	189	nreqs nready npending nthreads
211	max_poll_time max_poll_reqs	190	max_poll_time max_poll_reqs
212	sendfile fadvise);	191	sendfile fadvise madvise
		192	mmap munmap munlock munlockall);
213		193
214	push @AIO_REQ, qw(aio_busy); # not exported	194	push @AIO_REQ, qw(aio_busy); # not exported
215		195
216	@IO::AIO::GRP::ISA = 'IO::AIO::REQ';	196	@IO::AIO::GRP::ISA = 'IO::AIO::REQ';
217		197
218	require XSLoader;	198	require XSLoader;
219	XSLoader::load ("IO::AIO", $VERSION);	199	XSLoader::load ("IO::AIO", $VERSION);
220	}	200	}
221		201
222	=head1 FUNCTIONS	202	=head1 FUNCTIONS
		203
		204	=head2 QUICK OVERVIEW
		205
		206	This section simply lists the prototypes of the most important functions
		207	for quick reference. See the following sections for function-by-function
		208	documentation.
		209
		210	aio_open $pathname, $flags, $mode, $callback->($fh)
		211	aio_close $fh, $callback->($status)
		212	aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
		213	aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
		214	aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval)
		215	aio_readahead $fh,$offset,$length, $callback->($retval)
		216	aio_stat $fh_or_path, $callback->($status)
		217	aio_lstat $fh, $callback->($status)
		218	aio_statvfs $fh_or_path, $callback->($statvfs)
		219	aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
		220	aio_chown $fh_or_path, $uid, $gid, $callback->($status)
		221	aio_truncate $fh_or_path, $offset, $callback->($status)
		222	aio_chmod $fh_or_path, $mode, $callback->($status)
		223	aio_unlink $pathname, $callback->($status)
		224	aio_mknod $path, $mode, $dev, $callback->($status)
		225	aio_link $srcpath, $dstpath, $callback->($status)
		226	aio_symlink $srcpath, $dstpath, $callback->($status)
		227	aio_readlink $path, $callback->($link)
		228	aio_realpath $path, $callback->($link)
		229	aio_rename $srcpath, $dstpath, $callback->($status)
		230	aio_mkdir $pathname, $mode, $callback->($status)
		231	aio_rmdir $pathname, $callback->($status)
		232	aio_readdir $pathname, $callback->($entries)
		233	aio_readdirx $pathname, $flags, $callback->($entries, $flags)
		234	IO::AIO::READDIR_DENTS IO::AIO::READDIR_DIRS_FIRST
		235	IO::AIO::READDIR_STAT_ORDER IO::AIO::READDIR_FOUND_UNKNOWN
		236	aio_load $path, $data, $callback->($status)
		237	aio_copy $srcpath, $dstpath, $callback->($status)
		238	aio_move $srcpath, $dstpath, $callback->($status)
		239	aio_scandir $path, $maxreq, $callback->($dirs, $nondirs)
		240	aio_rmtree $path, $callback->($status)
		241	aio_sync $callback->($status)
		242	aio_syncfs $fh, $callback->($status)
		243	aio_fsync $fh, $callback->($status)
		244	aio_fdatasync $fh, $callback->($status)
		245	aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status)
		246	aio_pathsync $path, $callback->($status)
		247	aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
		248	aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
		249	aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status)
		250	aio_mlockall $flags, $callback->($status)
		251	aio_group $callback->(...)
		252	aio_nop $callback->()
		253
		254	$prev_pri = aioreq_pri [$pri]
		255	aioreq_nice $pri_adjust
		256
		257	IO::AIO::poll_wait
		258	IO::AIO::poll_cb
		259	IO::AIO::poll
		260	IO::AIO::flush
		261	IO::AIO::max_poll_reqs $nreqs
		262	IO::AIO::max_poll_time $seconds
		263	IO::AIO::min_parallel $nthreads
		264	IO::AIO::max_parallel $nthreads
		265	IO::AIO::max_idle $nthreads
		266	IO::AIO::idle_timeout $seconds
		267	IO::AIO::max_outstanding $maxreqs
		268	IO::AIO::nreqs
		269	IO::AIO::nready
		270	IO::AIO::npending
		271
		272	IO::AIO::sendfile $ofh, $ifh, $offset, $count
		273	IO::AIO::fadvise $fh, $offset, $len, $advice
		274	IO::AIO::madvise $scalar, $offset, $length, $advice
		275	IO::AIO::mprotect $scalar, $offset, $length, $protect
		276	IO::AIO::munlock $scalar, $offset = 0, $length = undef
		277	IO::AIO::munlockall
223		278
224	=head2 AIO REQUEST FUNCTIONS	279	=head2 AIO REQUEST FUNCTIONS
225		280
226	All the C<aio_*> calls are more or less thin wrappers around the syscall	281	All the C<aio_*> calls are more or less thin wrappers around the syscall
227	with the same name (sans C<aio_>). The arguments are similar or identical,	282	with the same name (sans C<aio_>). The arguments are similar or identical,
…		…
307	by the umask in effect then the request is being executed, so better never	362	by the umask in effect then the request is being executed, so better never
308	change the umask.	363	change the umask.
309		364
310	Example:	365	Example:
311		366
312	aio_open "/etc/passwd", O_RDONLY, 0, sub {	367	aio_open "/etc/passwd", IO::AIO::O_RDONLY, 0, sub {
313	if ($_[0]) {	368	if ($_[0]) {
314	print "open successful, fh is $_[0]\n";	369	print "open successful, fh is $_[0]\n";
315	...	370	...
316	} else {	371	} else {
317	die "open failed: $!\n";	372	die "open failed: $!\n";
318	}	373	}
319	};	374	};
320		375
		376	In addition to all the common open modes/flags (C<O_RDONLY>, C<O_WRONLY>,
		377	C<O_RDWR>, C<O_CREAT>, C<O_TRUNC>, C<O_EXCL> and C<O_APPEND>), the
		378	following POSIX and non-POSIX constants are available (missing ones on
		379	your system are, as usual, C<0>):
		380
		381	C<O_ASYNC>, C<O_DIRECT>, C<O_NOATIME>, C<O_CLOEXEC>, C<O_NOCTTY>, C<O_NOFOLLOW>,
		382	C<O_NONBLOCK>, C<O_EXEC>, C<O_SEARCH>, C<O_DIRECTORY>, C<O_DSYNC>,
		383	C<O_RSYNC>, C<O_SYNC> and C<O_TTY_INIT>.
		384
321		385
322	=item aio_close $fh, $callback->($status)	386	=item aio_close $fh, $callback->($status)
323		387
324	Asynchronously close a file and call the callback with the result	388	Asynchronously close a file and call the callback with the result
325	code.	389	code.
…		…
375		439
376	Tries to copy C<$length> bytes from C<$in_fh> to C<$out_fh>. It starts	440	Tries to copy C<$length> bytes from C<$in_fh> to C<$out_fh>. It starts
377	reading at byte offset C<$in_offset>, and starts writing at the current	441	reading at byte offset C<$in_offset>, and starts writing at the current
378	file offset of C<$out_fh>. Because of that, it is not safe to issue more	442	file offset of C<$out_fh>. Because of that, it is not safe to issue more
379	than one C<aio_sendfile> per C<$out_fh>, as they will interfere with each	443	than one C<aio_sendfile> per C<$out_fh>, as they will interfere with each
380	other.	444	other. The same C<$in_fh> works fine though, as this function does not
		445	move or use the file offset of C<$in_fh>.
381		446
		447	Please note that C<aio_sendfile> can read more bytes from C<$in_fh> than
		448	are written, and there is no way to find out how many more bytes have been
		449	read from C<aio_sendfile> alone, as C<aio_sendfile> only provides the
		450	number of bytes written to C<$out_fh>. Only if the result value equals
		451	C<$length> one can assume that C<$length> bytes have been read.
		452
		453	Unlike with other C<aio_> functions, it makes a lot of sense to use
		454	C<aio_sendfile> on non-blocking sockets, as long as one end (typically
		455	the C<$in_fh>) is a file - the file I/O will then be asynchronous, while
		456	the socket I/O will be non-blocking. Note, however, that you can run
		457	into a trap where C<aio_sendfile> reads some data with readahead, then
		458	fails to write all data, and when the socket is ready the next time, the
		459	data in the cache is already lost, forcing C<aio_sendfile> to again hit
		460	the disk. Explicit C<aio_read> + C<aio_write> let's you better control
		461	resource usage.
		462
382	This call tries to make use of a native C<sendfile> syscall to provide	463	This call tries to make use of a native C<sendfile>-like syscall to
383	zero-copy operation. For this to work, C<$out_fh> should refer to a	464	provide zero-copy operation. For this to work, C<$out_fh> should refer to
384	socket, and C<$in_fh> should refer to mmap'able file.	465	a socket, and C<$in_fh> should refer to an mmap'able file.
385		466
386	If a native sendfile cannot be found or it fails with C<ENOSYS>,	467	If a native sendfile cannot be found or it fails with C<ENOSYS>,
387	C<ENOTSUP>, C<EOPNOTSUPP>, C<EAFNOSUPPORT>, C<EPROTOTYPE> or C<ENOTSOCK>,	468	C<EINVAL>, C<ENOTSUP>, C<EOPNOTSUPP>, C<EAFNOSUPPORT>, C<EPROTOTYPE> or
388	it will be emulated, so you can call C<aio_sendfile> on any type of	469	C<ENOTSOCK>, it will be emulated, so you can call C<aio_sendfile> on any
389	filehandle regardless of the limitations of the operating system.	470	type of filehandle regardless of the limitations of the operating system.
390		471
391	Please note, however, that C<aio_sendfile> can read more bytes from	472	As native sendfile syscalls (as practically any non-POSIX interface hacked
392	C<$in_fh> than are written, and there is no way to find out how many	473	together in a hurry to improve benchmark numbers) tend to be rather buggy
393	bytes have been read from C<aio_sendfile> alone, as C<aio_sendfile> only	474	on many systems, this implementation tries to work around some known bugs
394	provides the number of bytes written to C<$out_fh>. Only if the result	475	in Linux and FreeBSD kernels (probably others, too), but that might fail,
395	value equals C<$length> one can assume that C<$length> bytes have been	476	so you really really should check the return value of C<aio_sendfile> -
396	read.	477	fewre bytes than expected might have been transferred.
397		478
398		479
399	=item aio_readahead $fh,$offset,$length, $callback->($retval)	480	=item aio_readahead $fh,$offset,$length, $callback->($retval)
400		481
401	C<aio_readahead> populates the page cache with data from a file so that	482	C<aio_readahead> populates the page cache with data from a file so that
…		…
424		505
425	Currently, the stats are always 64-bit-stats, i.e. instead of returning an	506	Currently, the stats are always 64-bit-stats, i.e. instead of returning an
426	error when stat'ing a large file, the results will be silently truncated	507	error when stat'ing a large file, the results will be silently truncated
427	unless perl itself is compiled with large file support.	508	unless perl itself is compiled with large file support.
428		509
		510	To help interpret the mode and dev/rdev stat values, IO::AIO offers the
		511	following constants and functions (if not implemented, the constants will
		512	be C<0> and the functions will either C<croak> or fall back on traditional
		513	behaviour).
		514
		515	C<S_IFMT>, C<S_IFIFO>, C<S_IFCHR>, C<S_IFBLK>, C<S_IFLNK>, C<S_IFREG>,
		516	C<S_IFDIR>, C<S_IFWHT>, C<S_IFSOCK>, C<IO::AIO::major $dev_t>,
		517	C<IO::AIO::minor $dev_t>, C<IO::AIO::makedev $major, $minor>.
		518
429	Example: Print the length of F</etc/passwd>:	519	Example: Print the length of F</etc/passwd>:
430		520
431	aio_stat "/etc/passwd", sub {	521	aio_stat "/etc/passwd", sub {
432	$_[0] and die "stat failed: $!";	522	$_[0] and die "stat failed: $!";
433	print "size is ", -s _, "\n";	523	print "size is ", -s _, "\n";
434	};	524	};
435		525
436		526
		527	=item aio_statvfs $fh_or_path, $callback->($statvfs)
		528
		529	Works like the POSIX C<statvfs> or C<fstatvfs> syscalls, depending on
		530	whether a file handle or path was passed.
		531
		532	On success, the callback is passed a hash reference with the following
		533	members: C<bsize>, C<frsize>, C<blocks>, C<bfree>, C<bavail>, C<files>,
		534	C<ffree>, C<favail>, C<fsid>, C<flag> and C<namemax>. On failure, C<undef>
		535	is passed.
		536
		537	The following POSIX IO::AIO::ST_* constants are defined: C<ST_RDONLY> and
		538	C<ST_NOSUID>.
		539
		540	The following non-POSIX IO::AIO::ST_* flag masks are defined to
		541	their correct value when available, or to C<0> on systems that do
		542	not support them: C<ST_NODEV>, C<ST_NOEXEC>, C<ST_SYNCHRONOUS>,
		543	C<ST_MANDLOCK>, C<ST_WRITE>, C<ST_APPEND>, C<ST_IMMUTABLE>, C<ST_NOATIME>,
		544	C<ST_NODIRATIME> and C<ST_RELATIME>.
		545
		546	Example: stat C</wd> and dump out the data if successful.
		547
		548	aio_statvfs "/wd", sub {
		549	my $f = $_[0]
		550	or die "statvfs: $!";
		551
		552	use Data::Dumper;
		553	say Dumper $f;
		554	};
		555
		556	# result:
		557	{
		558	bsize => 1024,
		559	bfree => 4333064312,
		560	blocks => 10253828096,
		561	files => 2050765568,
		562	flag => 4096,
		563	favail => 2042092649,
		564	bavail => 4333064312,
		565	ffree => 2042092649,
		566	namemax => 255,
		567	frsize => 1024,
		568	fsid => 1810
		569	}
		570
		571
437	=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status)	572	=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
438		573
439	Works like perl's C<utime> function (including the special case of $atime	574	Works like perl's C<utime> function (including the special case of $atime
440	and $mtime being undef). Fractional times are supported if the underlying	575	and $mtime being undef). Fractional times are supported if the underlying
441	syscalls support them.	576	syscalls support them.
…		…
489		624
490	The only (POSIX-) portable way of calling this function is:	625	The only (POSIX-) portable way of calling this function is:
491		626
492	aio_mknod $path, IO::AIO::S_IFIFO \| $mode, 0, sub { ...	627	aio_mknod $path, IO::AIO::S_IFIFO \| $mode, 0, sub { ...
493		628
		629	See C<aio_stat> for info about some potentially helpful extra constants
		630	and functions.
494		631
495	=item aio_link $srcpath, $dstpath, $callback->($status)	632	=item aio_link $srcpath, $dstpath, $callback->($status)
496		633
497	Asynchronously create a new link to the existing object at C<$srcpath> at	634	Asynchronously create a new link to the existing object at C<$srcpath> at
498	the path C<$dstpath> and call the callback with the result code.	635	the path C<$dstpath> and call the callback with the result code.
…		…
509	Asynchronously read the symlink specified by C<$path> and pass it to	646	Asynchronously read the symlink specified by C<$path> and pass it to
510	the callback. If an error occurs, nothing or undef gets passed to the	647	the callback. If an error occurs, nothing or undef gets passed to the
511	callback.	648	callback.
512		649
513		650
		651	=item aio_realpath $path, $callback->($path)
		652
		653	Asynchronously make the path absolute and resolve any symlinks in
		654	C<$path>. The resulting path only consists of directories (Same as
		655	L<Cwd::realpath>).
		656
		657	This request can be used to get the absolute path of the current working
		658	directory by passing it a path of F<.> (a single dot).
		659
		660
514	=item aio_rename $srcpath, $dstpath, $callback->($status)	661	=item aio_rename $srcpath, $dstpath, $callback->($status)
515		662
516	Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as	663	Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as
517	rename(2) and call the callback with the result code.	664	rename(2) and call the callback with the result code.
518		665
…		…
551		698
552	=over 4	699	=over 4
553		700
554	=item IO::AIO::READDIR_DENTS	701	=item IO::AIO::READDIR_DENTS
555		702
556	When this flag is off, then the callback gets an arrayref with of names	703	When this flag is off, then the callback gets an arrayref consisting of
557	only (as with C<aio_readdir>), otherwise it gets an arrayref with	704	names only (as with C<aio_readdir>), otherwise it gets an arrayref with
558	C<[$name, $type, $inode]> arrayrefs, each describing a single directory	705	C<[$name, $type, $inode]> arrayrefs, each describing a single directory
559	entry in more detail.	706	entry in more detail.
560		707
561	C<$name> is the name of the entry.	708	C<$name> is the name of the entry.
562		709
…		…
575	systems that do not deliver the inode information.	722	systems that do not deliver the inode information.
576		723
577	=item IO::AIO::READDIR_DIRS_FIRST	724	=item IO::AIO::READDIR_DIRS_FIRST
578		725
579	When this flag is set, then the names will be returned in an order where	726	When this flag is set, then the names will be returned in an order where
580	likely directories come first. This is useful when you need to quickly	727	likely directories come first, in optimal stat order. This is useful when
581	find directories, or you want to find all directories while avoiding to	728	you need to quickly find directories, or you want to find all directories
582	stat() each entry.	729	while avoiding to stat() each entry.
583		730
584	If the system returns type information in readdir, then this is used	731	If the system returns type information in readdir, then this is used
585	to find directories directly. Otherwise, likely directories are files	732	to find directories directly. Otherwise, likely directories are names
586	beginning with ".", or otherwise files with no dots, of which files with	733	beginning with ".", or otherwise names with no dots, of which names with
587	short names are tried first.	734	short names are tried first.
588		735
589	=item IO::AIO::READDIR_STAT_ORDER	736	=item IO::AIO::READDIR_STAT_ORDER
590		737
591	When this flag is set, then the names will be returned in an order	738	When this flag is set, then the names will be returned in an order
…		…
736	if ($_[0] && $! == EXDEV) {	883	if ($_[0] && $! == EXDEV) {
737	aioreq_pri $pri;	884	aioreq_pri $pri;
738	add $grp aio_copy $src, $dst, sub {	885	add $grp aio_copy $src, $dst, sub {
739	$grp->result ($_[0]);	886	$grp->result ($_[0]);
740		887
741	if (!$_[0]) {	888	unless ($_[0]) {
742	aioreq_pri $pri;	889	aioreq_pri $pri;
743	add $grp aio_unlink $src;	890	add $grp aio_unlink $src;
744	}	891	}
745	};	892	};
746	} else {	893	} else {
…		…
938	callback with the fdatasync result code.	1085	callback with the fdatasync result code.
939		1086
940	If this call isn't available because your OS lacks it or it couldn't be	1087	If this call isn't available because your OS lacks it or it couldn't be
941	detected, it will be emulated by calling C<fsync> instead.	1088	detected, it will be emulated by calling C<fsync> instead.
942		1089
		1090	=item aio_syncfs $fh, $callback->($status)
		1091
		1092	Asynchronously call the syncfs syscall to sync the filesystem associated
		1093	to the given filehandle and call the callback with the syncfs result
		1094	code. If syncfs is not available, calls sync(), but returns C<-1> and sets
		1095	errno to C<ENOSYS> nevertheless.
		1096
943	=item aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status)	1097	=item aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status)
944		1098
945	Sync the data portion of the file specified by C<$offset> and C<$length>	1099	Sync the data portion of the file specified by C<$offset> and C<$length>
946	to disk (but NOT the metadata), by calling the Linux-specific	1100	to disk (but NOT the metadata), by calling the Linux-specific
947	sync_file_range call. If sync_file_range is not available or it returns	1101	sync_file_range call. If sync_file_range is not available or it returns
…		…
994	}	1148	}
995		1149
996	=item aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)	1150	=item aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
997		1151
998	This is a rather advanced IO::AIO call, which only works on mmap(2)ed	1152	This is a rather advanced IO::AIO call, which only works on mmap(2)ed
999	scalars (see the L<Sys::Mmap> or L<Mmap> modules for details on this, note	1153	scalars (see the C<IO::AIO::mmap> function, although it also works on data
		1154	scalars managed by the L<Sys::Mmap> or L<Mmap> modules, note that the
1000	that the scalar must only be modified in-place while an aio operation is	1155	scalar must only be modified in-place while an aio operation is pending on
1001	pending on it).	1156	it).
1002		1157
1003	It calls the C<msync> function of your OS, if available, with the memory	1158	It calls the C<msync> function of your OS, if available, with the memory
1004	area starting at C<$offset> in the string and ending C<$length> bytes	1159	area starting at C<$offset> in the string and ending C<$length> bytes
1005	later. If C<$length> is negative, counts from the end, and if C<$length>	1160	later. If C<$length> is negative, counts from the end, and if C<$length>
1006	is C<undef>, then it goes till the end of the string. The flags can be	1161	is C<undef>, then it goes till the end of the string. The flags can be
…		…
1017	as for C<aio_msync>, above, except for flags, which must be either	1172	as for C<aio_msync>, above, except for flags, which must be either
1018	C<0> (which reads all pages and ensures they are instantiated) or	1173	C<0> (which reads all pages and ensures they are instantiated) or
1019	C<IO::AIO::MT_MODIFY>, which modifies the memory page s(by reading and	1174	C<IO::AIO::MT_MODIFY>, which modifies the memory page s(by reading and
1020	writing an octet from it, which dirties the page).	1175	writing an octet from it, which dirties the page).
1021		1176
		1177	=item aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status)
		1178
		1179	This is a rather advanced IO::AIO call, which works best on mmap(2)ed
		1180	scalars.
		1181
		1182	It reads in all the pages of the underlying storage into memory (if any)
		1183	and locks them, so they are not getting swapped/paged out or removed.
		1184
		1185	If C<$length> is undefined, then the scalar will be locked till the end.
		1186
		1187	On systems that do not implement C<mlock>, this function returns C<-1>
		1188	and sets errno to C<ENOSYS>.
		1189
		1190	Note that the corresponding C<munlock> is synchronous and is
		1191	documented under L<MISCELLANEOUS FUNCTIONS>.
		1192
		1193	Example: open a file, mmap and mlock it - both will be undone when
		1194	C<$data> gets destroyed.
		1195
		1196	open my $fh, "<", $path or die "$path: $!";
		1197	my $data;
		1198	IO::AIO::mmap $data, -s $fh, IO::AIO::PROT_READ, IO::AIO::MAP_SHARED, $fh;
		1199	aio_mlock $data; # mlock in background
		1200
		1201	=item aio_mlockall $flags, $callback->($status)
		1202
		1203	Calls the C<mlockall> function with the given C<$flags> (a combination of
		1204	C<IO::AIO::MCL_CURRENT> and C<IO::AIO::MCL_FUTURE>).
		1205
		1206	On systems that do not implement C<mlockall>, this function returns C<-1>
		1207	and sets errno to C<ENOSYS>.
		1208
		1209	Note that the corresponding C<munlockall> is synchronous and is
		1210	documented under L<MISCELLANEOUS FUNCTIONS>.
		1211
		1212	Example: asynchronously lock all current and future pages into memory.
		1213
		1214	aio_mlockall IO::AIO::MCL_FUTURE;
		1215
1022	=item aio_group $callback->(...)	1216	=item aio_group $callback->(...)
1023		1217
1024	This is a very special aio request: Instead of doing something, it is a	1218	This is a very special aio request: Instead of doing something, it is a
1025	container for other aio requests, which is useful if you want to bundle	1219	container for other aio requests, which is useful if you want to bundle
1026	many requests into a single, composite, request with a definite callback	1220	many requests into a single, composite, request with a definite callback
…		…
1249		1443
1250	See C<poll_cb> for an example.	1444	See C<poll_cb> for an example.
1251		1445
1252	=item IO::AIO::poll_cb	1446	=item IO::AIO::poll_cb
1253		1447
1254	Process some outstanding events on the result pipe. You have to call this	1448	Process some outstanding events on the result pipe. You have to call
1255	regularly. Returns C<0> if all events could be processed, or C<-1> if it	1449	this regularly. Returns C<0> if all events could be processed (or there
1256	returned earlier for whatever reason. Returns immediately when no events	1450	were no events to process), or C<-1> if it returned earlier for whatever
1257	are outstanding. The amount of events processed depends on the settings of	1451	reason. Returns immediately when no events are outstanding. The amount of
1258	C<IO::AIO::max_poll_req> and C<IO::AIO::max_poll_time>.	1452	events processed depends on the settings of C<IO::AIO::max_poll_req> and
		1453	C<IO::AIO::max_poll_time>.
1259		1454
1260	If not all requests were processed for whatever reason, the filehandle	1455	If not all requests were processed for whatever reason, the filehandle
1261	will still be ready when C<poll_cb> returns, so normally you don't have to	1456	will still be ready when C<poll_cb> returns, so normally you don't have to
1262	do anything special to have it called later.	1457	do anything special to have it called later.
1263		1458
		1459	Apart from calling C<IO::AIO::poll_cb> when the event filehandle becomes
		1460	ready, it can be beneficial to call this function from loops which submit
		1461	a lot of requests, to make sure the results get processed when they become
		1462	available and not just when the loop is finished and the event loop takes
		1463	over again. This function returns very fast when there are no outstanding
		1464	requests.
		1465
1264	Example: Install an Event watcher that automatically calls	1466	Example: Install an Event watcher that automatically calls
1265	IO::AIO::poll_cb with high priority (more examples can be found in the	1467	IO::AIO::poll_cb with high priority (more examples can be found in the
1266	SYNOPSIS section, at the top of this document):	1468	SYNOPSIS section, at the top of this document):
1267		1469
1268	Event->io (fd => IO::AIO::poll_fileno,	1470	Event->io (fd => IO::AIO::poll_fileno,
1269	poll => 'r', async => 1,	1471	poll => 'r', async => 1,
1270	cb => \&IO::AIO::poll_cb);	1472	cb => \&IO::AIO::poll_cb);
		1473
		1474	=item IO::AIO::poll_wait
		1475
		1476	If there are any outstanding requests and none of them in the result
		1477	phase, wait till the result filehandle becomes ready for reading (simply
		1478	does a C<select> on the filehandle. This is useful if you want to
		1479	synchronously wait for some requests to finish).
		1480
		1481	See C<nreqs> for an example.
		1482
		1483	=item IO::AIO::poll
		1484
		1485	Waits until some requests have been handled.
		1486
		1487	Returns the number of requests processed, but is otherwise strictly
		1488	equivalent to:
		1489
		1490	IO::AIO::poll_wait, IO::AIO::poll_cb
		1491
		1492	=item IO::AIO::flush
		1493
		1494	Wait till all outstanding AIO requests have been handled.
		1495
		1496	Strictly equivalent to:
		1497
		1498	IO::AIO::poll_wait, IO::AIO::poll_cb
		1499	while IO::AIO::nreqs;
1271		1500
1272	=item IO::AIO::max_poll_reqs $nreqs	1501	=item IO::AIO::max_poll_reqs $nreqs
1273		1502
1274	=item IO::AIO::max_poll_time $seconds	1503	=item IO::AIO::max_poll_time $seconds
1275		1504
…		…
1300	# use a low priority so other tasks have priority	1529	# use a low priority so other tasks have priority
1301	Event->io (fd => IO::AIO::poll_fileno,	1530	Event->io (fd => IO::AIO::poll_fileno,
1302	poll => 'r', nice => 1,	1531	poll => 'r', nice => 1,
1303	cb => &IO::AIO::poll_cb);	1532	cb => &IO::AIO::poll_cb);
1304		1533
1305	=item IO::AIO::poll_wait
1306
1307	If there are any outstanding requests and none of them in the result
1308	phase, wait till the result filehandle becomes ready for reading (simply
1309	does a C<select> on the filehandle. This is useful if you want to
1310	synchronously wait for some requests to finish).
1311
1312	See C<nreqs> for an example.
1313
1314	=item IO::AIO::poll
1315
1316	Waits until some requests have been handled.
1317
1318	Returns the number of requests processed, but is otherwise strictly
1319	equivalent to:
1320
1321	IO::AIO::poll_wait, IO::AIO::poll_cb
1322
1323	=item IO::AIO::flush
1324
1325	Wait till all outstanding AIO requests have been handled.
1326
1327	Strictly equivalent to:
1328
1329	IO::AIO::poll_wait, IO::AIO::poll_cb
1330	while IO::AIO::nreqs;
1331
1332	=back	1534	=back
1333		1535
1334	=head3 CONTROLLING THE NUMBER OF THREADS	1536	=head3 CONTROLLING THE NUMBER OF THREADS
1335		1537
1336	=over	1538	=over
…		…
1369		1571
1370	Under normal circumstances you don't need to call this function.	1572	Under normal circumstances you don't need to call this function.
1371		1573
1372	=item IO::AIO::max_idle $nthreads	1574	=item IO::AIO::max_idle $nthreads
1373		1575
1374	Limit the number of threads (default: 4) that are allowed to idle (i.e.,	1576	Limit the number of threads (default: 4) that are allowed to idle
1375	threads that did not get a request to process within 10 seconds). That	1577	(i.e., threads that did not get a request to process within the idle
1376	means if a thread becomes idle while C<$nthreads> other threads are also	1578	timeout (default: 10 seconds). That means if a thread becomes idle while
1377	idle, it will free its resources and exit.	1579	C<$nthreads> other threads are also idle, it will free its resources and
		1580	exit.
1378		1581
1379	This is useful when you allow a large number of threads (e.g. 100 or 1000)	1582	This is useful when you allow a large number of threads (e.g. 100 or 1000)
1380	to allow for extremely high load situations, but want to free resources	1583	to allow for extremely high load situations, but want to free resources
1381	under normal circumstances (1000 threads can easily consume 30MB of RAM).	1584	under normal circumstances (1000 threads can easily consume 30MB of RAM).
1382		1585
1383	The default is probably ok in most situations, especially if thread	1586	The default is probably ok in most situations, especially if thread
1384	creation is fast. If thread creation is very slow on your system you might	1587	creation is fast. If thread creation is very slow on your system you might
1385	want to use larger values.	1588	want to use larger values.
1386		1589
		1590	=item IO::AIO::idle_timeout $seconds
		1591
		1592	Sets the minimum idle timeout (default 10) after which worker threads are
		1593	allowed to exit. SEe C<IO::AIO::max_idle>.
		1594
1387	=item IO::AIO::max_outstanding $maxreqs	1595	=item IO::AIO::max_outstanding $maxreqs
		1596
		1597	Sets the maximum number of outstanding requests to C<$nreqs>. If
		1598	you do queue up more than this number of requests, the next call to
		1599	C<IO::AIO::poll_cb> (and other functions calling C<poll_cb>, such as
		1600	C<IO::AIO::flush> or C<IO::AIO::poll>) will block until the limit is no
		1601	longer exceeded.
		1602
		1603	In other words, this setting does not enforce a queue limit, but can be
		1604	used to make poll functions block if the limit is exceeded.
1388		1605
1389	This is a very bad function to use in interactive programs because it	1606	This is a very bad function to use in interactive programs because it
1390	blocks, and a bad way to reduce concurrency because it is inexact: Better	1607	blocks, and a bad way to reduce concurrency because it is inexact: Better
1391	use an C<aio_group> together with a feed callback.	1608	use an C<aio_group> together with a feed callback.
1392		1609
1393	Sets the maximum number of outstanding requests to C<$nreqs>. If you	1610	It's main use is in scripts without an event loop - when you want to stat
1394	do queue up more than this number of requests, the next call to the	1611	a lot of files, you can write somehting like this:
1395	C<poll_cb> (and C<poll_some> and other functions calling C<poll_cb>)
1396	function will block until the limit is no longer exceeded.
1397		1612
1398	The default value is very large, so there is no practical limit on the	1613	IO::AIO::max_outstanding 32;
1399	number of outstanding requests.
1400		1614
1401	You can still queue as many requests as you want. Therefore,	1615	for my $path (...) {
1402	C<max_outstanding> is mainly useful in simple scripts (with low values) or	1616	aio_stat $path , ...;
1403	as a stop gap to shield against fatal memory overflow (with large values).	1617	IO::AIO::poll_cb;
		1618	}
		1619
		1620	IO::AIO::flush;
		1621
		1622	The call to C<poll_cb> inside the loop will normally return instantly, but
		1623	as soon as more thna C<32> reqeusts are in-flight, it will block until
		1624	some requests have been handled. This keeps the loop from pushing a large
		1625	number of C<aio_stat> requests onto the queue.
		1626
		1627	The default value for C<max_outstanding> is very large, so there is no
		1628	practical limit on the number of outstanding requests.
1404		1629
1405	=back	1630	=back
1406		1631
1407	=head3 STATISTICAL INFORMATION	1632	=head3 STATISTICAL INFORMATION
1408		1633
…		…
1446		1671
1447	Returns the number of bytes copied, or C<-1> on error.	1672	Returns the number of bytes copied, or C<-1> on error.
1448		1673
1449	=item IO::AIO::fadvise $fh, $offset, $len, $advice	1674	=item IO::AIO::fadvise $fh, $offset, $len, $advice
1450		1675
1451	Simply calls the C<posix_fadvise> function (see it's	1676	Simply calls the C<posix_fadvise> function (see its
1452	manpage for details). The following advice constants are	1677	manpage for details). The following advice constants are
1453	avaiable: C<IO::AIO::FADV_NORMAL>, C<IO::AIO::FADV_SEQUENTIAL>,	1678	avaiable: C<IO::AIO::FADV_NORMAL>, C<IO::AIO::FADV_SEQUENTIAL>,
1454	C<IO::AIO::FADV_RANDOM>, C<IO::AIO::FADV_NOREUSE>,	1679	C<IO::AIO::FADV_RANDOM>, C<IO::AIO::FADV_NOREUSE>,
1455	C<IO::AIO::FADV_WILLNEED>, C<IO::AIO::FADV_DONTNEED>.	1680	C<IO::AIO::FADV_WILLNEED>, C<IO::AIO::FADV_DONTNEED>.
1456		1681
1457	On systems that do not implement C<posix_fadvise>, this function returns	1682	On systems that do not implement C<posix_fadvise>, this function returns
1458	ENOSYS, otherwise the return value of C<posix_fadvise>.	1683	ENOSYS, otherwise the return value of C<posix_fadvise>.
1459		1684
		1685	=item IO::AIO::madvise $scalar, $offset, $len, $advice
		1686
		1687	Simply calls the C<posix_madvise> function (see its
		1688	manpage for details). The following advice constants are
		1689	avaiable: C<IO::AIO::MADV_NORMAL>, C<IO::AIO::MADV_SEQUENTIAL>,
		1690	C<IO::AIO::MADV_RANDOM>, C<IO::AIO::MADV_WILLNEED>, C<IO::AIO::MADV_DONTNEED>.
		1691
		1692	On systems that do not implement C<posix_madvise>, this function returns
		1693	ENOSYS, otherwise the return value of C<posix_madvise>.
		1694
		1695	=item IO::AIO::mprotect $scalar, $offset, $len, $protect
		1696
		1697	Simply calls the C<mprotect> function on the preferably AIO::mmap'ed
		1698	$scalar (see its manpage for details). The following protect
		1699	constants are avaiable: C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_READ>,
		1700	C<IO::AIO::PROT_WRITE>, C<IO::AIO::PROT_EXEC>.
		1701
		1702	On systems that do not implement C<mprotect>, this function returns
		1703	ENOSYS, otherwise the return value of C<mprotect>.
		1704
		1705	=item IO::AIO::mmap $scalar, $length, $prot, $flags, $fh[, $offset]
		1706
		1707	Memory-maps a file (or anonymous memory range) and attaches it to the
		1708	given C<$scalar>, which will act like a string scalar.
		1709
		1710	The only operations allowed on the scalar are C<substr>/C<vec> that don't
		1711	change the string length, and most read-only operations such as copying it
		1712	or searching it with regexes and so on.
		1713
		1714	Anything else is unsafe and will, at best, result in memory leaks.
		1715
		1716	The memory map associated with the C<$scalar> is automatically removed
		1717	when the C<$scalar> is destroyed, or when the C<IO::AIO::mmap> or
		1718	C<IO::AIO::munmap> functions are called.
		1719
		1720	This calls the C<mmap>(2) function internally. See your system's manual
		1721	page for details on the C<$length>, C<$prot> and C<$flags> parameters.
		1722
		1723	The C<$length> must be larger than zero and smaller than the actual
		1724	filesize.
		1725
		1726	C<$prot> is a combination of C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_EXEC>,
		1727	C<IO::AIO::PROT_READ> and/or C<IO::AIO::PROT_WRITE>,
		1728
		1729	C<$flags> can be a combination of C<IO::AIO::MAP_SHARED> or
		1730	C<IO::AIO::MAP_PRIVATE>, or a number of system-specific flags (when
		1731	not available, the are defined as 0): C<IO::AIO::MAP_ANONYMOUS>
		1732	(which is set to C<MAP_ANON> if your system only provides this
		1733	constant), C<IO::AIO::MAP_HUGETLB>, C<IO::AIO::MAP_LOCKED>,
		1734	C<IO::AIO::MAP_NORESERVE>, C<IO::AIO::MAP_POPULATE> or
		1735	C<IO::AIO::MAP_NONBLOCK>
		1736
		1737	If C<$fh> is C<undef>, then a file descriptor of C<-1> is passed.
		1738
		1739	C<$offset> is the offset from the start of the file - it generally must be
		1740	a multiple of C<IO::AIO::PAGESIZE> and defaults to C<0>.
		1741
		1742	Example:
		1743
		1744	use Digest::MD5;
		1745	use IO::AIO;
		1746
		1747	open my $fh, "<verybigfile"
		1748	or die "$!";
		1749
		1750	IO::AIO::mmap my $data, -s $fh, IO::AIO::PROT_READ, IO::AIO::MAP_SHARED, $fh
		1751	or die "verybigfile: $!";
		1752
		1753	my $fast_md5 = md5 $data;
		1754
		1755	=item IO::AIO::munmap $scalar
		1756
		1757	Removes a previous mmap and undefines the C<$scalar>.
		1758
		1759	=item IO::AIO::munlock $scalar, $offset = 0, $length = undef
		1760
		1761	Calls the C<munlock> function, undoing the effects of a previous
		1762	C<aio_mlock> call (see its description for details).
		1763
		1764	=item IO::AIO::munlockall
		1765
		1766	Calls the C<munlockall> function.
		1767
		1768	On systems that do not implement C<munlockall>, this function returns
		1769	ENOSYS, otherwise the return value of C<munlockall>.
		1770
1460	=back	1771	=back
1461		1772
1462	=cut	1773	=cut
1463		1774
1464	min_parallel 8;	1775	min_parallel 8;
1465		1776
1466	END { flush }	1777	END { flush }
1467		1778
1468	1;	1779	1;
1469		1780
		1781	=head1 EVENT LOOP INTEGRATION
		1782
		1783	It is recommended to use L<AnyEvent::AIO> to integrate IO::AIO
		1784	automatically into many event loops:
		1785
		1786	# AnyEvent integration (EV, Event, Glib, Tk, POE, urxvt, pureperl...)
		1787	use AnyEvent::AIO;
		1788
		1789	You can also integrate IO::AIO manually into many event loops, here are
		1790	some examples of how to do this:
		1791
		1792	# EV integration
		1793	my $aio_w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb;
		1794
		1795	# Event integration
		1796	Event->io (fd => IO::AIO::poll_fileno,
		1797	poll => 'r',
		1798	cb => \&IO::AIO::poll_cb);
		1799
		1800	# Glib/Gtk2 integration
		1801	add_watch Glib::IO IO::AIO::poll_fileno,
		1802	in => sub { IO::AIO::poll_cb; 1 };
		1803
		1804	# Tk integration
		1805	Tk::Event::IO->fileevent (IO::AIO::poll_fileno, "",
		1806	readable => \&IO::AIO::poll_cb);
		1807
		1808	# Danga::Socket integration
		1809	Danga::Socket->AddOtherFds (IO::AIO::poll_fileno =>
		1810	\&IO::AIO::poll_cb);
		1811
1470	=head2 FORK BEHAVIOUR	1812	=head2 FORK BEHAVIOUR
1471		1813
1472	This module should do "the right thing" when the process using it forks:	1814	Usage of pthreads in a program changes the semantics of fork
		1815	considerably. Specifically, only async-safe functions can be called after
		1816	fork. Perl doesn't know about this, so in general, you cannot call fork
		1817	with defined behaviour in perl if pthreads are involved. IO::AIO uses
		1818	pthreads, so this applies, but many other extensions and (for inexplicable
		1819	reasons) perl itself often is linked against pthreads, so this limitation
		1820	applies to quite a lot of perls.
1473		1821
1474	Before the fork, IO::AIO enters a quiescent state where no requests	1822	This module no longer tries to fight your OS, or POSIX. That means IO::AIO
1475	can be added in other threads and no results will be processed. After	1823	only works in the process that loaded it. Forking is fully supported, but
1476	the fork the parent simply leaves the quiescent state and continues	1824	using IO::AIO in the child is not.
1477	request/result processing, while the child frees the request/result queue
1478	(so that the requests started before the fork will only be handled in the
1479	parent). Threads will be started on demand until the limit set in the
1480	parent process has been reached again.
1481		1825
1482	In short: the parent will, after a short pause, continue as if fork had	1826	You might get around by not I<using> IO::AIO before (or after)
1483	not been called, while the child will act as if IO::AIO has not been used	1827	forking. You could also try to call the L<IO::AIO::reinit> function in the
1484	yet.	1828	child:
		1829
		1830	=over 4
		1831
		1832	=item IO::AIO::reinit
		1833
		1834	Abondons all current requests and I/O threads and simply reinitialises all
		1835	data structures. This is not an operation suppported by any standards, but
		1836	happens to work on GNU/Linux and some newer BSD systems.
		1837
		1838	The only reasonable use for this function is to call it after forking, if
		1839	C<IO::AIO> was used in the parent. Calling it while IO::AIO is active in
		1840	the process will result in undefined behaviour. Calling it at any time
		1841	will also result in any undefined (by POSIX) behaviour.
		1842
		1843	=back
1485		1844
1486	=head2 MEMORY USAGE	1845	=head2 MEMORY USAGE
1487		1846
1488	Per-request usage:	1847	Per-request usage:
1489		1848

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Comparing IO-AIO/AIO.pm (file contents): Revision 1.171 by root, Sat Jan 2 14:24:32 2010 UTC vs. Revision 1.206 by root, Sun Jul 24 03:32:51 2011 UTC

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Comparing IO-AIO/AIO.pm (file contents):
Revision 1.171 by root, Sat Jan 2 14:24:32 2010 UTC vs.
Revision 1.206 by root, Sun Jul 24 03:32:51 2011 UTC