[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 1.201 by root, Tue Jul 5 09:24:11 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.
		653
		654	This request can be used to get the absolute path of the current working
		655	directory by passing it a path of F<.> (a single dot).
		656
		657
514	=item aio_rename $srcpath, $dstpath, $callback->($status)	658	=item aio_rename $srcpath, $dstpath, $callback->($status)
515		659
516	Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as	660	Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as
517	rename(2) and call the callback with the result code.	661	rename(2) and call the callback with the result code.
518		662
…		…
551		695
552	=over 4	696	=over 4
553		697
554	=item IO::AIO::READDIR_DENTS	698	=item IO::AIO::READDIR_DENTS
555		699
556	When this flag is off, then the callback gets an arrayref with of names	700	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	701	names only (as with C<aio_readdir>), otherwise it gets an arrayref with
558	C<[$name, $type, $inode]> arrayrefs, each describing a single directory	702	C<[$name, $type, $inode]> arrayrefs, each describing a single directory
559	entry in more detail.	703	entry in more detail.
560		704
561	C<$name> is the name of the entry.	705	C<$name> is the name of the entry.
562		706
…		…
575	systems that do not deliver the inode information.	719	systems that do not deliver the inode information.
576		720
577	=item IO::AIO::READDIR_DIRS_FIRST	721	=item IO::AIO::READDIR_DIRS_FIRST
578		722
579	When this flag is set, then the names will be returned in an order where	723	When this flag is set, then the names will be returned in an order where
580	likely directories come first. This is useful when you need to quickly	724	likely directories come first, in optimal stat order. This is useful when
581	find directories, or you want to find all directories while avoiding to	725	you need to quickly find directories, or you want to find all directories
582	stat() each entry.	726	while avoiding to stat() each entry.
583		727
584	If the system returns type information in readdir, then this is used	728	If the system returns type information in readdir, then this is used
585	to find directories directly. Otherwise, likely directories are files	729	to find directories directly. Otherwise, likely directories are names
586	beginning with ".", or otherwise files with no dots, of which files with	730	beginning with ".", or otherwise names with no dots, of which names with
587	short names are tried first.	731	short names are tried first.
588		732
589	=item IO::AIO::READDIR_STAT_ORDER	733	=item IO::AIO::READDIR_STAT_ORDER
590		734
591	When this flag is set, then the names will be returned in an order	735	When this flag is set, then the names will be returned in an order
…		…
736	if ($_[0] && $! == EXDEV) {	880	if ($_[0] && $! == EXDEV) {
737	aioreq_pri $pri;	881	aioreq_pri $pri;
738	add $grp aio_copy $src, $dst, sub {	882	add $grp aio_copy $src, $dst, sub {
739	$grp->result ($_[0]);	883	$grp->result ($_[0]);
740		884
741	if (!$_[0]) {	885	unless ($_[0]) {
742	aioreq_pri $pri;	886	aioreq_pri $pri;
743	add $grp aio_unlink $src;	887	add $grp aio_unlink $src;
744	}	888	}
745	};	889	};
746	} else {	890	} else {
…		…
994	}	1138	}
995		1139
996	=item aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)	1140	=item aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
997		1141
998	This is a rather advanced IO::AIO call, which only works on mmap(2)ed	1142	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	1143	scalars (see the C<IO::AIO::mmap> function, although it also works on data
		1144	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	1145	scalar must only be modified in-place while an aio operation is pending on
1001	pending on it).	1146	it).
1002		1147
1003	It calls the C<msync> function of your OS, if available, with the memory	1148	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	1149	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>	1150	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	1151	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	1162	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	1163	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	1164	C<IO::AIO::MT_MODIFY>, which modifies the memory page s(by reading and
1020	writing an octet from it, which dirties the page).	1165	writing an octet from it, which dirties the page).
1021		1166
		1167	=item aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status)
		1168
		1169	This is a rather advanced IO::AIO call, which works best on mmap(2)ed
		1170	scalars.
		1171
		1172	It reads in all the pages of the underlying storage into memory (if any)
		1173	and locks them, so they are not getting swapped/paged out or removed.
		1174
		1175	If C<$length> is undefined, then the scalar will be locked till the end.
		1176
		1177	On systems that do not implement C<mlock>, this function returns C<-1>
		1178	and sets errno to C<ENOSYS>.
		1179
		1180	Note that the corresponding C<munlock> is synchronous and is
		1181	documented under L<MISCELLANEOUS FUNCTIONS>.
		1182
		1183	Example: open a file, mmap and mlock it - both will be undone when
		1184	C<$data> gets destroyed.
		1185
		1186	open my $fh, "<", $path or die "$path: $!";
		1187	my $data;
		1188	IO::AIO::mmap $data, -s $fh, IO::AIO::PROT_READ, IO::AIO::MAP_SHARED, $fh;
		1189	aio_mlock $data; # mlock in background
		1190
		1191	=item aio_mlockall $flags, $callback->($status)
		1192
		1193	Calls the C<mlockall> function with the given C<$flags> (a combination of
		1194	C<IO::AIO::MCL_CURRENT> and C<IO::AIO::MCL_FUTURE>).
		1195
		1196	On systems that do not implement C<mlockall>, this function returns C<-1>
		1197	and sets errno to C<ENOSYS>.
		1198
		1199	Note that the corresponding C<munlockall> is synchronous and is
		1200	documented under L<MISCELLANEOUS FUNCTIONS>.
		1201
		1202	Example: asynchronously lock all current and future pages into memory.
		1203
		1204	aio_mlockall IO::AIO::MCL_FUTURE;
		1205
1022	=item aio_group $callback->(...)	1206	=item aio_group $callback->(...)
1023		1207
1024	This is a very special aio request: Instead of doing something, it is a	1208	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	1209	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	1210	many requests into a single, composite, request with a definite callback
…		…
1249		1433
1250	See C<poll_cb> for an example.	1434	See C<poll_cb> for an example.
1251		1435
1252	=item IO::AIO::poll_cb	1436	=item IO::AIO::poll_cb
1253		1437
1254	Process some outstanding events on the result pipe. You have to call this	1438	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	1439	this regularly. Returns C<0> if all events could be processed (or there
1256	returned earlier for whatever reason. Returns immediately when no events	1440	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	1441	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>.	1442	events processed depends on the settings of C<IO::AIO::max_poll_req> and
		1443	C<IO::AIO::max_poll_time>.
1259		1444
1260	If not all requests were processed for whatever reason, the filehandle	1445	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	1446	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.	1447	do anything special to have it called later.
1263		1448
		1449	Apart from calling C<IO::AIO::poll_cb> when the event filehandle becomes
		1450	ready, it can be beneficial to call this function from loops which submit
		1451	a lot of requests, to make sure the results get processed when they become
		1452	available and not just when the loop is finished and the event loop takes
		1453	over again. This function returns very fast when there are no outstanding
		1454	requests.
		1455
1264	Example: Install an Event watcher that automatically calls	1456	Example: Install an Event watcher that automatically calls
1265	IO::AIO::poll_cb with high priority (more examples can be found in the	1457	IO::AIO::poll_cb with high priority (more examples can be found in the
1266	SYNOPSIS section, at the top of this document):	1458	SYNOPSIS section, at the top of this document):
1267		1459
1268	Event->io (fd => IO::AIO::poll_fileno,	1460	Event->io (fd => IO::AIO::poll_fileno,
1269	poll => 'r', async => 1,	1461	poll => 'r', async => 1,
1270	cb => \&IO::AIO::poll_cb);	1462	cb => \&IO::AIO::poll_cb);
		1463
		1464	=item IO::AIO::poll_wait
		1465
		1466	If there are any outstanding requests and none of them in the result
		1467	phase, wait till the result filehandle becomes ready for reading (simply
		1468	does a C<select> on the filehandle. This is useful if you want to
		1469	synchronously wait for some requests to finish).
		1470
		1471	See C<nreqs> for an example.
		1472
		1473	=item IO::AIO::poll
		1474
		1475	Waits until some requests have been handled.
		1476
		1477	Returns the number of requests processed, but is otherwise strictly
		1478	equivalent to:
		1479
		1480	IO::AIO::poll_wait, IO::AIO::poll_cb
		1481
		1482	=item IO::AIO::flush
		1483
		1484	Wait till all outstanding AIO requests have been handled.
		1485
		1486	Strictly equivalent to:
		1487
		1488	IO::AIO::poll_wait, IO::AIO::poll_cb
		1489	while IO::AIO::nreqs;
1271		1490
1272	=item IO::AIO::max_poll_reqs $nreqs	1491	=item IO::AIO::max_poll_reqs $nreqs
1273		1492
1274	=item IO::AIO::max_poll_time $seconds	1493	=item IO::AIO::max_poll_time $seconds
1275		1494
…		…
1300	# use a low priority so other tasks have priority	1519	# use a low priority so other tasks have priority
1301	Event->io (fd => IO::AIO::poll_fileno,	1520	Event->io (fd => IO::AIO::poll_fileno,
1302	poll => 'r', nice => 1,	1521	poll => 'r', nice => 1,
1303	cb => &IO::AIO::poll_cb);	1522	cb => &IO::AIO::poll_cb);
1304		1523
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	1524	=back
1333		1525
1334	=head3 CONTROLLING THE NUMBER OF THREADS	1526	=head3 CONTROLLING THE NUMBER OF THREADS
1335		1527
1336	=over	1528	=over
…		…
1369		1561
1370	Under normal circumstances you don't need to call this function.	1562	Under normal circumstances you don't need to call this function.
1371		1563
1372	=item IO::AIO::max_idle $nthreads	1564	=item IO::AIO::max_idle $nthreads
1373		1565
1374	Limit the number of threads (default: 4) that are allowed to idle (i.e.,	1566	Limit the number of threads (default: 4) that are allowed to idle
1375	threads that did not get a request to process within 10 seconds). That	1567	(i.e., threads that did not get a request to process within the idle
1376	means if a thread becomes idle while C<$nthreads> other threads are also	1568	timeout (default: 10 seconds). That means if a thread becomes idle while
1377	idle, it will free its resources and exit.	1569	C<$nthreads> other threads are also idle, it will free its resources and
		1570	exit.
1378		1571
1379	This is useful when you allow a large number of threads (e.g. 100 or 1000)	1572	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	1573	to allow for extremely high load situations, but want to free resources
1381	under normal circumstances (1000 threads can easily consume 30MB of RAM).	1574	under normal circumstances (1000 threads can easily consume 30MB of RAM).
1382		1575
1383	The default is probably ok in most situations, especially if thread	1576	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	1577	creation is fast. If thread creation is very slow on your system you might
1385	want to use larger values.	1578	want to use larger values.
1386		1579
		1580	=item IO::AIO::idle_timeout $seconds
		1581
		1582	Sets the minimum idle timeout (default 10) after which worker threads are
		1583	allowed to exit. SEe C<IO::AIO::max_idle>.
		1584
1387	=item IO::AIO::max_outstanding $maxreqs	1585	=item IO::AIO::max_outstanding $maxreqs
		1586
		1587	Sets the maximum number of outstanding requests to C<$nreqs>. If
		1588	you do queue up more than this number of requests, the next call to
		1589	C<IO::AIO::poll_cb> (and other functions calling C<poll_cb>, such as
		1590	C<IO::AIO::flush> or C<IO::AIO::poll>) will block until the limit is no
		1591	longer exceeded.
		1592
		1593	In other words, this setting does not enforce a queue limit, but can be
		1594	used to make poll functions block if the limit is exceeded.
1388		1595
1389	This is a very bad function to use in interactive programs because it	1596	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	1597	blocks, and a bad way to reduce concurrency because it is inexact: Better
1391	use an C<aio_group> together with a feed callback.	1598	use an C<aio_group> together with a feed callback.
1392		1599
1393	Sets the maximum number of outstanding requests to C<$nreqs>. If you	1600	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	1601	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		1602
1398	The default value is very large, so there is no practical limit on the	1603	IO::AIO::max_outstanding 32;
1399	number of outstanding requests.
1400		1604
1401	You can still queue as many requests as you want. Therefore,	1605	for my $path (...) {
1402	C<max_outstanding> is mainly useful in simple scripts (with low values) or	1606	aio_stat $path , ...;
1403	as a stop gap to shield against fatal memory overflow (with large values).	1607	IO::AIO::poll_cb;
		1608	}
		1609
		1610	IO::AIO::flush;
		1611
		1612	The call to C<poll_cb> inside the loop will normally return instantly, but
		1613	as soon as more thna C<32> reqeusts are in-flight, it will block until
		1614	some requests have been handled. This keeps the loop from pushing a large
		1615	number of C<aio_stat> requests onto the queue.
		1616
		1617	The default value for C<max_outstanding> is very large, so there is no
		1618	practical limit on the number of outstanding requests.
1404		1619
1405	=back	1620	=back
1406		1621
1407	=head3 STATISTICAL INFORMATION	1622	=head3 STATISTICAL INFORMATION
1408		1623
…		…
1446		1661
1447	Returns the number of bytes copied, or C<-1> on error.	1662	Returns the number of bytes copied, or C<-1> on error.
1448		1663
1449	=item IO::AIO::fadvise $fh, $offset, $len, $advice	1664	=item IO::AIO::fadvise $fh, $offset, $len, $advice
1450		1665
1451	Simply calls the C<posix_fadvise> function (see it's	1666	Simply calls the C<posix_fadvise> function (see its
1452	manpage for details). The following advice constants are	1667	manpage for details). The following advice constants are
1453	avaiable: C<IO::AIO::FADV_NORMAL>, C<IO::AIO::FADV_SEQUENTIAL>,	1668	avaiable: C<IO::AIO::FADV_NORMAL>, C<IO::AIO::FADV_SEQUENTIAL>,
1454	C<IO::AIO::FADV_RANDOM>, C<IO::AIO::FADV_NOREUSE>,	1669	C<IO::AIO::FADV_RANDOM>, C<IO::AIO::FADV_NOREUSE>,
1455	C<IO::AIO::FADV_WILLNEED>, C<IO::AIO::FADV_DONTNEED>.	1670	C<IO::AIO::FADV_WILLNEED>, C<IO::AIO::FADV_DONTNEED>.
1456		1671
1457	On systems that do not implement C<posix_fadvise>, this function returns	1672	On systems that do not implement C<posix_fadvise>, this function returns
1458	ENOSYS, otherwise the return value of C<posix_fadvise>.	1673	ENOSYS, otherwise the return value of C<posix_fadvise>.
1459		1674
		1675	=item IO::AIO::madvise $scalar, $offset, $len, $advice
		1676
		1677	Simply calls the C<posix_madvise> function (see its
		1678	manpage for details). The following advice constants are
		1679	avaiable: C<IO::AIO::MADV_NORMAL>, C<IO::AIO::MADV_SEQUENTIAL>,
		1680	C<IO::AIO::MADV_RANDOM>, C<IO::AIO::MADV_WILLNEED>, C<IO::AIO::MADV_DONTNEED>.
		1681
		1682	On systems that do not implement C<posix_madvise>, this function returns
		1683	ENOSYS, otherwise the return value of C<posix_madvise>.
		1684
		1685	=item IO::AIO::mprotect $scalar, $offset, $len, $protect
		1686
		1687	Simply calls the C<mprotect> function on the preferably AIO::mmap'ed
		1688	$scalar (see its manpage for details). The following protect
		1689	constants are avaiable: C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_READ>,
		1690	C<IO::AIO::PROT_WRITE>, C<IO::AIO::PROT_EXEC>.
		1691
		1692	On systems that do not implement C<mprotect>, this function returns
		1693	ENOSYS, otherwise the return value of C<mprotect>.
		1694
		1695	=item IO::AIO::mmap $scalar, $length, $prot, $flags, $fh[, $offset]
		1696
		1697	Memory-maps a file (or anonymous memory range) and attaches it to the
		1698	given C<$scalar>, which will act like a string scalar.
		1699
		1700	The only operations allowed on the scalar are C<substr>/C<vec> that don't
		1701	change the string length, and most read-only operations such as copying it
		1702	or searching it with regexes and so on.
		1703
		1704	Anything else is unsafe and will, at best, result in memory leaks.
		1705
		1706	The memory map associated with the C<$scalar> is automatically removed
		1707	when the C<$scalar> is destroyed, or when the C<IO::AIO::mmap> or
		1708	C<IO::AIO::munmap> functions are called.
		1709
		1710	This calls the C<mmap>(2) function internally. See your system's manual
		1711	page for details on the C<$length>, C<$prot> and C<$flags> parameters.
		1712
		1713	The C<$length> must be larger than zero and smaller than the actual
		1714	filesize.
		1715
		1716	C<$prot> is a combination of C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_EXEC>,
		1717	C<IO::AIO::PROT_READ> and/or C<IO::AIO::PROT_WRITE>,
		1718
		1719	C<$flags> can be a combination of C<IO::AIO::MAP_SHARED> or
		1720	C<IO::AIO::MAP_PRIVATE>, or a number of system-specific flags (when
		1721	not available, the are defined as 0): C<IO::AIO::MAP_ANONYMOUS>
		1722	(which is set to C<MAP_ANON> if your system only provides this
		1723	constant), C<IO::AIO::MAP_HUGETLB>, C<IO::AIO::MAP_LOCKED>,
		1724	C<IO::AIO::MAP_NORESERVE>, C<IO::AIO::MAP_POPULATE> or
		1725	C<IO::AIO::MAP_NONBLOCK>
		1726
		1727	If C<$fh> is C<undef>, then a file descriptor of C<-1> is passed.
		1728
		1729	C<$offset> is the offset from the start of the file - it generally must be
		1730	a multiple of C<IO::AIO::PAGESIZE> and defaults to C<0>.
		1731
		1732	Example:
		1733
		1734	use Digest::MD5;
		1735	use IO::AIO;
		1736
		1737	open my $fh, "<verybigfile"
		1738	or die "$!";
		1739
		1740	IO::AIO::mmap my $data, -s $fh, IO::AIO::PROT_READ, IO::AIO::MAP_SHARED, $fh
		1741	or die "verybigfile: $!";
		1742
		1743	my $fast_md5 = md5 $data;
		1744
		1745	=item IO::AIO::munmap $scalar
		1746
		1747	Removes a previous mmap and undefines the C<$scalar>.
		1748
		1749	=item IO::AIO::munlock $scalar, $offset = 0, $length = undef
		1750
		1751	Calls the C<munlock> function, undoing the effects of a previous
		1752	C<aio_mlock> call (see its description for details).
		1753
		1754	=item IO::AIO::munlockall
		1755
		1756	Calls the C<munlockall> function.
		1757
		1758	On systems that do not implement C<munlockall>, this function returns
		1759	ENOSYS, otherwise the return value of C<munlockall>.
		1760
1460	=back	1761	=back
1461		1762
1462	=cut	1763	=cut
1463		1764
1464	min_parallel 8;	1765	min_parallel 8;
1465		1766
1466	END { flush }	1767	END { flush }
1467		1768
1468	1;	1769	1;
1469		1770
		1771	=head1 EVENT LOOP INTEGRATION
		1772
		1773	It is recommended to use L<AnyEvent::AIO> to integrate IO::AIO
		1774	automatically into many event loops:
		1775
		1776	# AnyEvent integration (EV, Event, Glib, Tk, POE, urxvt, pureperl...)
		1777	use AnyEvent::AIO;
		1778
		1779	You can also integrate IO::AIO manually into many event loops, here are
		1780	some examples of how to do this:
		1781
		1782	# EV integration
		1783	my $aio_w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb;
		1784
		1785	# Event integration
		1786	Event->io (fd => IO::AIO::poll_fileno,
		1787	poll => 'r',
		1788	cb => \&IO::AIO::poll_cb);
		1789
		1790	# Glib/Gtk2 integration
		1791	add_watch Glib::IO IO::AIO::poll_fileno,
		1792	in => sub { IO::AIO::poll_cb; 1 };
		1793
		1794	# Tk integration
		1795	Tk::Event::IO->fileevent (IO::AIO::poll_fileno, "",
		1796	readable => \&IO::AIO::poll_cb);
		1797
		1798	# Danga::Socket integration
		1799	Danga::Socket->AddOtherFds (IO::AIO::poll_fileno =>
		1800	\&IO::AIO::poll_cb);
		1801
1470	=head2 FORK BEHAVIOUR	1802	=head2 FORK BEHAVIOUR
1471		1803
1472	This module should do "the right thing" when the process using it forks:	1804	Usage of pthreads in a program changes the semantics of fork
		1805	considerably. Specifically, only async-safe functions can be called after
		1806	fork. Perl doesn't know about this, so in general, you cannot call fork
		1807	with defined behaviour in perl. IO::AIO uses pthreads, so this applies,
		1808	but many other extensions and (for inexplicable reasons) perl itself often
		1809	is linked against pthreads, so this limitation applies.
1473		1810
1474	Before the fork, IO::AIO enters a quiescent state where no requests	1811	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	1812	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	1813	the time of this writing (2011) only GNU/Linux supports these extensions
1477	request/result processing, while the child frees the request/result queue	1814	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		1815
1486	=head2 MEMORY USAGE	1816	=head2 MEMORY USAGE
1487		1817
1488	Per-request usage:	1818	Per-request usage:
1489		1819

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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 1.201 by root, Tue Jul 5 09:24:11 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 1.201 by root, Tue Jul 5 09:24:11 2011 UTC