[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 1.202 by root, Tue Jul 5 14:02:15 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 = '3.93';
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 aio_fsync
201	aio_fdatasync aio_sync_file_range aio_pathsync aio_readahead	178	aio_fdatasync aio_sync_file_range aio_pathsync aio_readahead
202	aio_rename aio_link aio_move aio_copy aio_group	179	aio_rename aio_link aio_move aio_copy aio_group
203	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
204	aio_chmod aio_utime aio_truncate	181	aio_chmod aio_utime aio_truncate
		182	aio_msync aio_mtouch aio_mlock aio_mlockall
205	aio_msync aio_mtouch);	183	aio_statvfs);
206		184
207	our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice));	185	our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice));
208	our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush	186	our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush
209	min_parallel max_parallel max_idle	187	min_parallel max_parallel max_idle idle_timeout
210	nreqs nready npending nthreads	188	nreqs nready npending nthreads
211	max_poll_time max_poll_reqs	189	max_poll_time max_poll_reqs
212	sendfile fadvise);	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_realpath $path, $callback->($link)
		228	aio_rename $srcpath, $dstpath, $callback->($status)
		229	aio_mkdir $pathname, $mode, $callback->($status)
		230	aio_rmdir $pathname, $callback->($status)
		231	aio_readdir $pathname, $callback->($entries)
		232	aio_readdirx $pathname, $flags, $callback->($entries, $flags)
		233	IO::AIO::READDIR_DENTS IO::AIO::READDIR_DIRS_FIRST
		234	IO::AIO::READDIR_STAT_ORDER IO::AIO::READDIR_FOUND_UNKNOWN
		235	aio_load $path, $data, $callback->($status)
		236	aio_copy $srcpath, $dstpath, $callback->($status)
		237	aio_move $srcpath, $dstpath, $callback->($status)
		238	aio_scandir $path, $maxreq, $callback->($dirs, $nondirs)
		239	aio_rmtree $path, $callback->($status)
		240	aio_sync $callback->($status)
		241	aio_fsync $fh, $callback->($status)
		242	aio_fdatasync $fh, $callback->($status)
		243	aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status)
		244	aio_pathsync $path, $callback->($status)
		245	aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
		246	aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
		247	aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status)
		248	aio_mlockall $flags, $callback->($status)
		249	aio_group $callback->(...)
		250	aio_nop $callback->()
		251
		252	$prev_pri = aioreq_pri [$pri]
		253	aioreq_nice $pri_adjust
		254
		255	IO::AIO::poll_wait
		256	IO::AIO::poll_cb
		257	IO::AIO::poll
		258	IO::AIO::flush
		259	IO::AIO::max_poll_reqs $nreqs
		260	IO::AIO::max_poll_time $seconds
		261	IO::AIO::min_parallel $nthreads
		262	IO::AIO::max_parallel $nthreads
		263	IO::AIO::max_idle $nthreads
		264	IO::AIO::idle_timeout $seconds
		265	IO::AIO::max_outstanding $maxreqs
		266	IO::AIO::nreqs
		267	IO::AIO::nready
		268	IO::AIO::npending
		269
		270	IO::AIO::sendfile $ofh, $ifh, $offset, $count
		271	IO::AIO::fadvise $fh, $offset, $len, $advice
		272	IO::AIO::madvise $scalar, $offset, $length, $advice
		273	IO::AIO::mprotect $scalar, $offset, $length, $protect
		274	IO::AIO::munlock $scalar, $offset = 0, $length = undef
		275	IO::AIO::munlockall
223		276
224	=head2 AIO REQUEST FUNCTIONS	277	=head2 AIO REQUEST FUNCTIONS
225		278
226	All the C<aio_*> calls are more or less thin wrappers around the syscall	279	All the C<aio_*> calls are more or less thin wrappers around the syscall
227	with the same name (sans C<aio_>). The arguments are similar or identical,	280	with the same name (sans C<aio_>). The arguments are similar or identical,
…		…
307	by the umask in effect then the request is being executed, so better never	360	by the umask in effect then the request is being executed, so better never
308	change the umask.	361	change the umask.
309		362
310	Example:	363	Example:
311		364
312	aio_open "/etc/passwd", O_RDONLY, 0, sub {	365	aio_open "/etc/passwd", IO::AIO::O_RDONLY, 0, sub {
313	if ($_[0]) {	366	if ($_[0]) {
314	print "open successful, fh is $_[0]\n";	367	print "open successful, fh is $_[0]\n";
315	...	368	...
316	} else {	369	} else {
317	die "open failed: $!\n";	370	die "open failed: $!\n";
318	}	371	}
319	};	372	};
320		373
		374	In addition to all the common open modes/flags (C<O_RDONLY>, C<O_WRONLY>,
		375	C<O_RDWR>, C<O_CREAT>, C<O_TRUNC>, C<O_EXCL> and C<O_APPEND>), the
		376	following POSIX and non-POSIX constants are available (missing ones on
		377	your system are, as usual, C<0>):
		378
		379	C<O_ASYNC>, C<O_DIRECT>, C<O_NOATIME>, C<O_CLOEXEC>, C<O_NOCTTY>, C<O_NOFOLLOW>,
		380	C<O_NONBLOCK>, C<O_EXEC>, C<O_SEARCH>, C<O_DIRECTORY>, C<O_DSYNC>,
		381	C<O_RSYNC>, C<O_SYNC> and C<O_TTY_INIT>.
		382
321		383
322	=item aio_close $fh, $callback->($status)	384	=item aio_close $fh, $callback->($status)
323		385
324	Asynchronously close a file and call the callback with the result	386	Asynchronously close a file and call the callback with the result
325	code.	387	code.
…		…
375		437
376	Tries to copy C<$length> bytes from C<$in_fh> to C<$out_fh>. It starts	438	Tries to copy C<$length> bytes from C<$in_fh> to C<$out_fh>. It starts
377	reading at byte offset C<$in_offset>, and starts writing at the current	439	reading at byte offset C<$in_offset>, and starts writing at the current
378	file offset of C<$out_fh>. Because of that, it is not safe to issue more	440	file offset of C<$out_fh>. Because of that, it is not safe to issue more
379	than one C<aio_sendfile> per C<$out_fh>, as they will interfere with each	441	than one C<aio_sendfile> per C<$out_fh>, as they will interfere with each
380	other.	442	other. The same C<$in_fh> works fine though, as this function does not
		443	move or use the file offset of C<$in_fh>.
381		444
		445	Please note that C<aio_sendfile> can read more bytes from C<$in_fh> than
		446	are written, and there is no way to find out how many more bytes have been
		447	read from C<aio_sendfile> alone, as C<aio_sendfile> only provides the
		448	number of bytes written to C<$out_fh>. Only if the result value equals
		449	C<$length> one can assume that C<$length> bytes have been read.
		450
		451	Unlike with other C<aio_> functions, it makes a lot of sense to use
		452	C<aio_sendfile> on non-blocking sockets, as long as one end (typically
		453	the C<$in_fh>) is a file - the file I/O will then be asynchronous, while
		454	the socket I/O will be non-blocking. Note, however, that you can run
		455	into a trap where C<aio_sendfile> reads some data with readahead, then
		456	fails to write all data, and when the socket is ready the next time, the
		457	data in the cache is already lost, forcing C<aio_sendfile> to again hit
		458	the disk. Explicit C<aio_read> + C<aio_write> let's you better control
		459	resource usage.
		460
382	This call tries to make use of a native C<sendfile> syscall to provide	461	This call tries to make use of a native C<sendfile>-like syscall to
383	zero-copy operation. For this to work, C<$out_fh> should refer to a	462	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.	463	a socket, and C<$in_fh> should refer to an mmap'able file.
385		464
386	If a native sendfile cannot be found or it fails with C<ENOSYS>,	465	If a native sendfile cannot be found or it fails with C<ENOSYS>,
387	C<ENOTSUP>, C<EOPNOTSUPP>, C<EAFNOSUPPORT>, C<EPROTOTYPE> or C<ENOTSOCK>,	466	C<EINVAL>, C<ENOTSUP>, C<EOPNOTSUPP>, C<EAFNOSUPPORT>, C<EPROTOTYPE> or
388	it will be emulated, so you can call C<aio_sendfile> on any type of	467	C<ENOTSOCK>, it will be emulated, so you can call C<aio_sendfile> on any
389	filehandle regardless of the limitations of the operating system.	468	type of filehandle regardless of the limitations of the operating system.
390		469
391	Please note, however, that C<aio_sendfile> can read more bytes from	470	As native sendfile syscalls (as practically any non-POSIX interface hacked
392	C<$in_fh> than are written, and there is no way to find out how many	471	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	472	on many systems, this implementation tries to work around some known bugs
394	provides the number of bytes written to C<$out_fh>. Only if the result	473	in Linux and FreeBSD kernels (probably others, too), but that might fail,
395	value equals C<$length> one can assume that C<$length> bytes have been	474	so you really really should check the return value of C<aio_sendfile> -
396	read.	475	fewre bytes than expected might have been transferred.
397		476
398		477
399	=item aio_readahead $fh,$offset,$length, $callback->($retval)	478	=item aio_readahead $fh,$offset,$length, $callback->($retval)
400		479
401	C<aio_readahead> populates the page cache with data from a file so that	480	C<aio_readahead> populates the page cache with data from a file so that
…		…
424		503
425	Currently, the stats are always 64-bit-stats, i.e. instead of returning an	504	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	505	error when stat'ing a large file, the results will be silently truncated
427	unless perl itself is compiled with large file support.	506	unless perl itself is compiled with large file support.
428		507
		508	To help interpret the mode and dev/rdev stat values, IO::AIO offers the
		509	following constants and functions (if not implemented, the constants will
		510	be C<0> and the functions will either C<croak> or fall back on traditional
		511	behaviour).
		512
		513	C<S_IFMT>, C<S_IFIFO>, C<S_IFCHR>, C<S_IFBLK>, C<S_IFLNK>, C<S_IFREG>,
		514	C<S_IFDIR>, C<S_IFWHT>, C<S_IFSOCK>, C<IO::AIO::major $dev_t>,
		515	C<IO::AIO::minor $dev_t>, C<IO::AIO::makedev $major, $minor>.
		516
429	Example: Print the length of F</etc/passwd>:	517	Example: Print the length of F</etc/passwd>:
430		518
431	aio_stat "/etc/passwd", sub {	519	aio_stat "/etc/passwd", sub {
432	$_[0] and die "stat failed: $!";	520	$_[0] and die "stat failed: $!";
433	print "size is ", -s _, "\n";	521	print "size is ", -s _, "\n";
434	};	522	};
435		523
436		524
		525	=item aio_statvfs $fh_or_path, $callback->($statvfs)
		526
		527	Works like the POSIX C<statvfs> or C<fstatvfs> syscalls, depending on
		528	whether a file handle or path was passed.
		529
		530	On success, the callback is passed a hash reference with the following
		531	members: C<bsize>, C<frsize>, C<blocks>, C<bfree>, C<bavail>, C<files>,
		532	C<ffree>, C<favail>, C<fsid>, C<flag> and C<namemax>. On failure, C<undef>
		533	is passed.
		534
		535	The following POSIX IO::AIO::ST_* constants are defined: C<ST_RDONLY> and
		536	C<ST_NOSUID>.
		537
		538	The following non-POSIX IO::AIO::ST_* flag masks are defined to
		539	their correct value when available, or to C<0> on systems that do
		540	not support them: C<ST_NODEV>, C<ST_NOEXEC>, C<ST_SYNCHRONOUS>,
		541	C<ST_MANDLOCK>, C<ST_WRITE>, C<ST_APPEND>, C<ST_IMMUTABLE>, C<ST_NOATIME>,
		542	C<ST_NODIRATIME> and C<ST_RELATIME>.
		543
		544	Example: stat C</wd> and dump out the data if successful.
		545
		546	aio_statvfs "/wd", sub {
		547	my $f = $_[0]
		548	or die "statvfs: $!";
		549
		550	use Data::Dumper;
		551	say Dumper $f;
		552	};
		553
		554	# result:
		555	{
		556	bsize => 1024,
		557	bfree => 4333064312,
		558	blocks => 10253828096,
		559	files => 2050765568,
		560	flag => 4096,
		561	favail => 2042092649,
		562	bavail => 4333064312,
		563	ffree => 2042092649,
		564	namemax => 255,
		565	frsize => 1024,
		566	fsid => 1810
		567	}
		568
		569
437	=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status)	570	=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
438		571
439	Works like perl's C<utime> function (including the special case of $atime	572	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	573	and $mtime being undef). Fractional times are supported if the underlying
441	syscalls support them.	574	syscalls support them.
…		…
489		622
490	The only (POSIX-) portable way of calling this function is:	623	The only (POSIX-) portable way of calling this function is:
491		624
492	aio_mknod $path, IO::AIO::S_IFIFO \| $mode, 0, sub { ...	625	aio_mknod $path, IO::AIO::S_IFIFO \| $mode, 0, sub { ...
493		626
		627	See C<aio_stat> for info about some potentially helpful extra constants
		628	and functions.
494		629
495	=item aio_link $srcpath, $dstpath, $callback->($status)	630	=item aio_link $srcpath, $dstpath, $callback->($status)
496		631
497	Asynchronously create a new link to the existing object at C<$srcpath> at	632	Asynchronously create a new link to the existing object at C<$srcpath> at
498	the path C<$dstpath> and call the callback with the result code.	633	the path C<$dstpath> and call the callback with the result code.
…		…
509	Asynchronously read the symlink specified by C<$path> and pass it to	644	Asynchronously read the symlink specified by C<$path> and pass it to
510	the callback. If an error occurs, nothing or undef gets passed to the	645	the callback. If an error occurs, nothing or undef gets passed to the
511	callback.	646	callback.
512		647
513		648
		649	=item aio_realpath $path, $callback->($path)
		650
		651	Asynchronously make the path absolute and resolve any symlinks in
		652	C<$path>. The resulting path only consists of directories (Same as
		653	L<Cwd::realpath>).
		654
		655	This request can be used to get the absolute path of the current working
		656	directory by passing it a path of F<.> (a single dot).
		657
		658
514	=item aio_rename $srcpath, $dstpath, $callback->($status)	659	=item aio_rename $srcpath, $dstpath, $callback->($status)
515		660
516	Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as	661	Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as
517	rename(2) and call the callback with the result code.	662	rename(2) and call the callback with the result code.
518		663
…		…
551		696
552	=over 4	697	=over 4
553		698
554	=item IO::AIO::READDIR_DENTS	699	=item IO::AIO::READDIR_DENTS
555		700
556	When this flag is off, then the callback gets an arrayref with of names	701	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	702	names only (as with C<aio_readdir>), otherwise it gets an arrayref with
558	C<[$name, $type, $inode]> arrayrefs, each describing a single directory	703	C<[$name, $type, $inode]> arrayrefs, each describing a single directory
559	entry in more detail.	704	entry in more detail.
560		705
561	C<$name> is the name of the entry.	706	C<$name> is the name of the entry.
562		707
…		…
575	systems that do not deliver the inode information.	720	systems that do not deliver the inode information.
576		721
577	=item IO::AIO::READDIR_DIRS_FIRST	722	=item IO::AIO::READDIR_DIRS_FIRST
578		723
579	When this flag is set, then the names will be returned in an order where	724	When this flag is set, then the names will be returned in an order where
580	likely directories come first. This is useful when you need to quickly	725	likely directories come first, in optimal stat order. This is useful when
581	find directories, or you want to find all directories while avoiding to	726	you need to quickly find directories, or you want to find all directories
582	stat() each entry.	727	while avoiding to stat() each entry.
583		728
584	If the system returns type information in readdir, then this is used	729	If the system returns type information in readdir, then this is used
585	to find directories directly. Otherwise, likely directories are files	730	to find directories directly. Otherwise, likely directories are names
586	beginning with ".", or otherwise files with no dots, of which files with	731	beginning with ".", or otherwise names with no dots, of which names with
587	short names are tried first.	732	short names are tried first.
588		733
589	=item IO::AIO::READDIR_STAT_ORDER	734	=item IO::AIO::READDIR_STAT_ORDER
590		735
591	When this flag is set, then the names will be returned in an order	736	When this flag is set, then the names will be returned in an order
…		…
736	if ($_[0] && $! == EXDEV) {	881	if ($_[0] && $! == EXDEV) {
737	aioreq_pri $pri;	882	aioreq_pri $pri;
738	add $grp aio_copy $src, $dst, sub {	883	add $grp aio_copy $src, $dst, sub {
739	$grp->result ($_[0]);	884	$grp->result ($_[0]);
740		885
741	if (!$_[0]) {	886	unless ($_[0]) {
742	aioreq_pri $pri;	887	aioreq_pri $pri;
743	add $grp aio_unlink $src;	888	add $grp aio_unlink $src;
744	}	889	}
745	};	890	};
746	} else {	891	} else {
…		…
994	}	1139	}
995		1140
996	=item aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)	1141	=item aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
997		1142
998	This is a rather advanced IO::AIO call, which only works on mmap(2)ed	1143	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	1144	scalars (see the C<IO::AIO::mmap> function, although it also works on data
		1145	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	1146	scalar must only be modified in-place while an aio operation is pending on
1001	pending on it).	1147	it).
1002		1148
1003	It calls the C<msync> function of your OS, if available, with the memory	1149	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	1150	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>	1151	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	1152	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	1163	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	1164	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	1165	C<IO::AIO::MT_MODIFY>, which modifies the memory page s(by reading and
1020	writing an octet from it, which dirties the page).	1166	writing an octet from it, which dirties the page).
1021		1167
		1168	=item aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status)
		1169
		1170	This is a rather advanced IO::AIO call, which works best on mmap(2)ed
		1171	scalars.
		1172
		1173	It reads in all the pages of the underlying storage into memory (if any)
		1174	and locks them, so they are not getting swapped/paged out or removed.
		1175
		1176	If C<$length> is undefined, then the scalar will be locked till the end.
		1177
		1178	On systems that do not implement C<mlock>, this function returns C<-1>
		1179	and sets errno to C<ENOSYS>.
		1180
		1181	Note that the corresponding C<munlock> is synchronous and is
		1182	documented under L<MISCELLANEOUS FUNCTIONS>.
		1183
		1184	Example: open a file, mmap and mlock it - both will be undone when
		1185	C<$data> gets destroyed.
		1186
		1187	open my $fh, "<", $path or die "$path: $!";
		1188	my $data;
		1189	IO::AIO::mmap $data, -s $fh, IO::AIO::PROT_READ, IO::AIO::MAP_SHARED, $fh;
		1190	aio_mlock $data; # mlock in background
		1191
		1192	=item aio_mlockall $flags, $callback->($status)
		1193
		1194	Calls the C<mlockall> function with the given C<$flags> (a combination of
		1195	C<IO::AIO::MCL_CURRENT> and C<IO::AIO::MCL_FUTURE>).
		1196
		1197	On systems that do not implement C<mlockall>, this function returns C<-1>
		1198	and sets errno to C<ENOSYS>.
		1199
		1200	Note that the corresponding C<munlockall> is synchronous and is
		1201	documented under L<MISCELLANEOUS FUNCTIONS>.
		1202
		1203	Example: asynchronously lock all current and future pages into memory.
		1204
		1205	aio_mlockall IO::AIO::MCL_FUTURE;
		1206
1022	=item aio_group $callback->(...)	1207	=item aio_group $callback->(...)
1023		1208
1024	This is a very special aio request: Instead of doing something, it is a	1209	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	1210	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	1211	many requests into a single, composite, request with a definite callback
…		…
1249		1434
1250	See C<poll_cb> for an example.	1435	See C<poll_cb> for an example.
1251		1436
1252	=item IO::AIO::poll_cb	1437	=item IO::AIO::poll_cb
1253		1438
1254	Process some outstanding events on the result pipe. You have to call this	1439	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	1440	this regularly. Returns C<0> if all events could be processed (or there
1256	returned earlier for whatever reason. Returns immediately when no events	1441	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	1442	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>.	1443	events processed depends on the settings of C<IO::AIO::max_poll_req> and
		1444	C<IO::AIO::max_poll_time>.
1259		1445
1260	If not all requests were processed for whatever reason, the filehandle	1446	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	1447	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.	1448	do anything special to have it called later.
1263		1449
		1450	Apart from calling C<IO::AIO::poll_cb> when the event filehandle becomes
		1451	ready, it can be beneficial to call this function from loops which submit
		1452	a lot of requests, to make sure the results get processed when they become
		1453	available and not just when the loop is finished and the event loop takes
		1454	over again. This function returns very fast when there are no outstanding
		1455	requests.
		1456
1264	Example: Install an Event watcher that automatically calls	1457	Example: Install an Event watcher that automatically calls
1265	IO::AIO::poll_cb with high priority (more examples can be found in the	1458	IO::AIO::poll_cb with high priority (more examples can be found in the
1266	SYNOPSIS section, at the top of this document):	1459	SYNOPSIS section, at the top of this document):
1267		1460
1268	Event->io (fd => IO::AIO::poll_fileno,	1461	Event->io (fd => IO::AIO::poll_fileno,
1269	poll => 'r', async => 1,	1462	poll => 'r', async => 1,
1270	cb => \&IO::AIO::poll_cb);	1463	cb => \&IO::AIO::poll_cb);
		1464
		1465	=item IO::AIO::poll_wait
		1466
		1467	If there are any outstanding requests and none of them in the result
		1468	phase, wait till the result filehandle becomes ready for reading (simply
		1469	does a C<select> on the filehandle. This is useful if you want to
		1470	synchronously wait for some requests to finish).
		1471
		1472	See C<nreqs> for an example.
		1473
		1474	=item IO::AIO::poll
		1475
		1476	Waits until some requests have been handled.
		1477
		1478	Returns the number of requests processed, but is otherwise strictly
		1479	equivalent to:
		1480
		1481	IO::AIO::poll_wait, IO::AIO::poll_cb
		1482
		1483	=item IO::AIO::flush
		1484
		1485	Wait till all outstanding AIO requests have been handled.
		1486
		1487	Strictly equivalent to:
		1488
		1489	IO::AIO::poll_wait, IO::AIO::poll_cb
		1490	while IO::AIO::nreqs;
1271		1491
1272	=item IO::AIO::max_poll_reqs $nreqs	1492	=item IO::AIO::max_poll_reqs $nreqs
1273		1493
1274	=item IO::AIO::max_poll_time $seconds	1494	=item IO::AIO::max_poll_time $seconds
1275		1495
…		…
1300	# use a low priority so other tasks have priority	1520	# use a low priority so other tasks have priority
1301	Event->io (fd => IO::AIO::poll_fileno,	1521	Event->io (fd => IO::AIO::poll_fileno,
1302	poll => 'r', nice => 1,	1522	poll => 'r', nice => 1,
1303	cb => &IO::AIO::poll_cb);	1523	cb => &IO::AIO::poll_cb);
1304		1524
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	1525	=back
1333		1526
1334	=head3 CONTROLLING THE NUMBER OF THREADS	1527	=head3 CONTROLLING THE NUMBER OF THREADS
1335		1528
1336	=over	1529	=over
…		…
1369		1562
1370	Under normal circumstances you don't need to call this function.	1563	Under normal circumstances you don't need to call this function.
1371		1564
1372	=item IO::AIO::max_idle $nthreads	1565	=item IO::AIO::max_idle $nthreads
1373		1566
1374	Limit the number of threads (default: 4) that are allowed to idle (i.e.,	1567	Limit the number of threads (default: 4) that are allowed to idle
1375	threads that did not get a request to process within 10 seconds). That	1568	(i.e., threads that did not get a request to process within the idle
1376	means if a thread becomes idle while C<$nthreads> other threads are also	1569	timeout (default: 10 seconds). That means if a thread becomes idle while
1377	idle, it will free its resources and exit.	1570	C<$nthreads> other threads are also idle, it will free its resources and
		1571	exit.
1378		1572
1379	This is useful when you allow a large number of threads (e.g. 100 or 1000)	1573	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	1574	to allow for extremely high load situations, but want to free resources
1381	under normal circumstances (1000 threads can easily consume 30MB of RAM).	1575	under normal circumstances (1000 threads can easily consume 30MB of RAM).
1382		1576
1383	The default is probably ok in most situations, especially if thread	1577	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	1578	creation is fast. If thread creation is very slow on your system you might
1385	want to use larger values.	1579	want to use larger values.
1386		1580
		1581	=item IO::AIO::idle_timeout $seconds
		1582
		1583	Sets the minimum idle timeout (default 10) after which worker threads are
		1584	allowed to exit. SEe C<IO::AIO::max_idle>.
		1585
1387	=item IO::AIO::max_outstanding $maxreqs	1586	=item IO::AIO::max_outstanding $maxreqs
		1587
		1588	Sets the maximum number of outstanding requests to C<$nreqs>. If
		1589	you do queue up more than this number of requests, the next call to
		1590	C<IO::AIO::poll_cb> (and other functions calling C<poll_cb>, such as
		1591	C<IO::AIO::flush> or C<IO::AIO::poll>) will block until the limit is no
		1592	longer exceeded.
		1593
		1594	In other words, this setting does not enforce a queue limit, but can be
		1595	used to make poll functions block if the limit is exceeded.
1388		1596
1389	This is a very bad function to use in interactive programs because it	1597	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	1598	blocks, and a bad way to reduce concurrency because it is inexact: Better
1391	use an C<aio_group> together with a feed callback.	1599	use an C<aio_group> together with a feed callback.
1392		1600
1393	Sets the maximum number of outstanding requests to C<$nreqs>. If you	1601	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	1602	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		1603
1398	The default value is very large, so there is no practical limit on the	1604	IO::AIO::max_outstanding 32;
1399	number of outstanding requests.
1400		1605
1401	You can still queue as many requests as you want. Therefore,	1606	for my $path (...) {
1402	C<max_outstanding> is mainly useful in simple scripts (with low values) or	1607	aio_stat $path , ...;
1403	as a stop gap to shield against fatal memory overflow (with large values).	1608	IO::AIO::poll_cb;
		1609	}
		1610
		1611	IO::AIO::flush;
		1612
		1613	The call to C<poll_cb> inside the loop will normally return instantly, but
		1614	as soon as more thna C<32> reqeusts are in-flight, it will block until
		1615	some requests have been handled. This keeps the loop from pushing a large
		1616	number of C<aio_stat> requests onto the queue.
		1617
		1618	The default value for C<max_outstanding> is very large, so there is no
		1619	practical limit on the number of outstanding requests.
1404		1620
1405	=back	1621	=back
1406		1622
1407	=head3 STATISTICAL INFORMATION	1623	=head3 STATISTICAL INFORMATION
1408		1624
…		…
1446		1662
1447	Returns the number of bytes copied, or C<-1> on error.	1663	Returns the number of bytes copied, or C<-1> on error.
1448		1664
1449	=item IO::AIO::fadvise $fh, $offset, $len, $advice	1665	=item IO::AIO::fadvise $fh, $offset, $len, $advice
1450		1666
1451	Simply calls the C<posix_fadvise> function (see it's	1667	Simply calls the C<posix_fadvise> function (see its
1452	manpage for details). The following advice constants are	1668	manpage for details). The following advice constants are
1453	avaiable: C<IO::AIO::FADV_NORMAL>, C<IO::AIO::FADV_SEQUENTIAL>,	1669	avaiable: C<IO::AIO::FADV_NORMAL>, C<IO::AIO::FADV_SEQUENTIAL>,
1454	C<IO::AIO::FADV_RANDOM>, C<IO::AIO::FADV_NOREUSE>,	1670	C<IO::AIO::FADV_RANDOM>, C<IO::AIO::FADV_NOREUSE>,
1455	C<IO::AIO::FADV_WILLNEED>, C<IO::AIO::FADV_DONTNEED>.	1671	C<IO::AIO::FADV_WILLNEED>, C<IO::AIO::FADV_DONTNEED>.
1456		1672
1457	On systems that do not implement C<posix_fadvise>, this function returns	1673	On systems that do not implement C<posix_fadvise>, this function returns
1458	ENOSYS, otherwise the return value of C<posix_fadvise>.	1674	ENOSYS, otherwise the return value of C<posix_fadvise>.
1459		1675
		1676	=item IO::AIO::madvise $scalar, $offset, $len, $advice
		1677
		1678	Simply calls the C<posix_madvise> function (see its
		1679	manpage for details). The following advice constants are
		1680	avaiable: C<IO::AIO::MADV_NORMAL>, C<IO::AIO::MADV_SEQUENTIAL>,
		1681	C<IO::AIO::MADV_RANDOM>, C<IO::AIO::MADV_WILLNEED>, C<IO::AIO::MADV_DONTNEED>.
		1682
		1683	On systems that do not implement C<posix_madvise>, this function returns
		1684	ENOSYS, otherwise the return value of C<posix_madvise>.
		1685
		1686	=item IO::AIO::mprotect $scalar, $offset, $len, $protect
		1687
		1688	Simply calls the C<mprotect> function on the preferably AIO::mmap'ed
		1689	$scalar (see its manpage for details). The following protect
		1690	constants are avaiable: C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_READ>,
		1691	C<IO::AIO::PROT_WRITE>, C<IO::AIO::PROT_EXEC>.
		1692
		1693	On systems that do not implement C<mprotect>, this function returns
		1694	ENOSYS, otherwise the return value of C<mprotect>.
		1695
		1696	=item IO::AIO::mmap $scalar, $length, $prot, $flags, $fh[, $offset]
		1697
		1698	Memory-maps a file (or anonymous memory range) and attaches it to the
		1699	given C<$scalar>, which will act like a string scalar.
		1700
		1701	The only operations allowed on the scalar are C<substr>/C<vec> that don't
		1702	change the string length, and most read-only operations such as copying it
		1703	or searching it with regexes and so on.
		1704
		1705	Anything else is unsafe and will, at best, result in memory leaks.
		1706
		1707	The memory map associated with the C<$scalar> is automatically removed
		1708	when the C<$scalar> is destroyed, or when the C<IO::AIO::mmap> or
		1709	C<IO::AIO::munmap> functions are called.
		1710
		1711	This calls the C<mmap>(2) function internally. See your system's manual
		1712	page for details on the C<$length>, C<$prot> and C<$flags> parameters.
		1713
		1714	The C<$length> must be larger than zero and smaller than the actual
		1715	filesize.
		1716
		1717	C<$prot> is a combination of C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_EXEC>,
		1718	C<IO::AIO::PROT_READ> and/or C<IO::AIO::PROT_WRITE>,
		1719
		1720	C<$flags> can be a combination of C<IO::AIO::MAP_SHARED> or
		1721	C<IO::AIO::MAP_PRIVATE>, or a number of system-specific flags (when
		1722	not available, the are defined as 0): C<IO::AIO::MAP_ANONYMOUS>
		1723	(which is set to C<MAP_ANON> if your system only provides this
		1724	constant), C<IO::AIO::MAP_HUGETLB>, C<IO::AIO::MAP_LOCKED>,
		1725	C<IO::AIO::MAP_NORESERVE>, C<IO::AIO::MAP_POPULATE> or
		1726	C<IO::AIO::MAP_NONBLOCK>
		1727
		1728	If C<$fh> is C<undef>, then a file descriptor of C<-1> is passed.
		1729
		1730	C<$offset> is the offset from the start of the file - it generally must be
		1731	a multiple of C<IO::AIO::PAGESIZE> and defaults to C<0>.
		1732
		1733	Example:
		1734
		1735	use Digest::MD5;
		1736	use IO::AIO;
		1737
		1738	open my $fh, "<verybigfile"
		1739	or die "$!";
		1740
		1741	IO::AIO::mmap my $data, -s $fh, IO::AIO::PROT_READ, IO::AIO::MAP_SHARED, $fh
		1742	or die "verybigfile: $!";
		1743
		1744	my $fast_md5 = md5 $data;
		1745
		1746	=item IO::AIO::munmap $scalar
		1747
		1748	Removes a previous mmap and undefines the C<$scalar>.
		1749
		1750	=item IO::AIO::munlock $scalar, $offset = 0, $length = undef
		1751
		1752	Calls the C<munlock> function, undoing the effects of a previous
		1753	C<aio_mlock> call (see its description for details).
		1754
		1755	=item IO::AIO::munlockall
		1756
		1757	Calls the C<munlockall> function.
		1758
		1759	On systems that do not implement C<munlockall>, this function returns
		1760	ENOSYS, otherwise the return value of C<munlockall>.
		1761
1460	=back	1762	=back
1461		1763
1462	=cut	1764	=cut
1463		1765
1464	min_parallel 8;	1766	min_parallel 8;
1465		1767
1466	END { flush }	1768	END { flush }
1467		1769
1468	1;	1770	1;
1469		1771
		1772	=head1 EVENT LOOP INTEGRATION
		1773
		1774	It is recommended to use L<AnyEvent::AIO> to integrate IO::AIO
		1775	automatically into many event loops:
		1776
		1777	# AnyEvent integration (EV, Event, Glib, Tk, POE, urxvt, pureperl...)
		1778	use AnyEvent::AIO;
		1779
		1780	You can also integrate IO::AIO manually into many event loops, here are
		1781	some examples of how to do this:
		1782
		1783	# EV integration
		1784	my $aio_w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb;
		1785
		1786	# Event integration
		1787	Event->io (fd => IO::AIO::poll_fileno,
		1788	poll => 'r',
		1789	cb => \&IO::AIO::poll_cb);
		1790
		1791	# Glib/Gtk2 integration
		1792	add_watch Glib::IO IO::AIO::poll_fileno,
		1793	in => sub { IO::AIO::poll_cb; 1 };
		1794
		1795	# Tk integration
		1796	Tk::Event::IO->fileevent (IO::AIO::poll_fileno, "",
		1797	readable => \&IO::AIO::poll_cb);
		1798
		1799	# Danga::Socket integration
		1800	Danga::Socket->AddOtherFds (IO::AIO::poll_fileno =>
		1801	\&IO::AIO::poll_cb);
		1802
1470	=head2 FORK BEHAVIOUR	1803	=head2 FORK BEHAVIOUR
1471		1804
1472	This module should do "the right thing" when the process using it forks:	1805	Usage of pthreads in a program changes the semantics of fork
		1806	considerably. Specifically, only async-safe functions can be called after
		1807	fork. Perl doesn't know about this, so in general, you cannot call fork
		1808	with defined behaviour in perl. IO::AIO uses pthreads, so this applies,
		1809	but many other extensions and (for inexplicable reasons) perl itself often
		1810	is linked against pthreads, so this limitation applies.
1473		1811
1474	Before the fork, IO::AIO enters a quiescent state where no requests	1812	Some operating systems have extensions that allow safe use of fork, and
1475	can be added in other threads and no results will be processed. After	1813	this module should do "the right thing" on those, and tries on others. At
1476	the fork the parent simply leaves the quiescent state and continues	1814	the time of this writing (2011) only GNU/Linux supports these extensions
1477	request/result processing, while the child frees the request/result queue	1815	to POSIX.
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
1482	In short: the parent will, after a short pause, continue as if fork had
1483	not been called, while the child will act as if IO::AIO has not been used
1484	yet.
1485		1816
1486	=head2 MEMORY USAGE	1817	=head2 MEMORY USAGE
1487		1818
1488	Per-request usage:	1819	Per-request usage:
1489		1820

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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 1.202 by root, Tue Jul 5 14:02:15 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 1.202 by root, Tue Jul 5 14:02:15 2011 UTC