[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 1.203 by root, Thu Jul 7 22:36:18 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_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_fsync $fh, $callback->($status)
		243	aio_fdatasync $fh, $callback->($status)
		244	aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status)
		245	aio_pathsync $path, $callback->($status)
		246	aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
		247	aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
		248	aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status)
		249	aio_mlockall $flags, $callback->($status)
		250	aio_group $callback->(...)
		251	aio_nop $callback->()
		252
		253	$prev_pri = aioreq_pri [$pri]
		254	aioreq_nice $pri_adjust
		255
		256	IO::AIO::poll_wait
		257	IO::AIO::poll_cb
		258	IO::AIO::poll
		259	IO::AIO::flush
		260	IO::AIO::max_poll_reqs $nreqs
		261	IO::AIO::max_poll_time $seconds
		262	IO::AIO::min_parallel $nthreads
		263	IO::AIO::max_parallel $nthreads
		264	IO::AIO::max_idle $nthreads
		265	IO::AIO::idle_timeout $seconds
		266	IO::AIO::max_outstanding $maxreqs
		267	IO::AIO::nreqs
		268	IO::AIO::nready
		269	IO::AIO::npending
		270
		271	IO::AIO::sendfile $ofh, $ifh, $offset, $count
		272	IO::AIO::fadvise $fh, $offset, $len, $advice
		273	IO::AIO::madvise $scalar, $offset, $length, $advice
		274	IO::AIO::mprotect $scalar, $offset, $length, $protect
		275	IO::AIO::munlock $scalar, $offset = 0, $length = undef
		276	IO::AIO::munlockall
223		277
224	=head2 AIO REQUEST FUNCTIONS	278	=head2 AIO REQUEST FUNCTIONS
225		279
226	All the C<aio_*> calls are more or less thin wrappers around the syscall	280	All the C<aio_*> calls are more or less thin wrappers around the syscall
227	with the same name (sans C<aio_>). The arguments are similar or identical,	281	with the same name (sans C<aio_>). The arguments are similar or identical,
…		…
307	by the umask in effect then the request is being executed, so better never	361	by the umask in effect then the request is being executed, so better never
308	change the umask.	362	change the umask.
309		363
310	Example:	364	Example:
311		365
312	aio_open "/etc/passwd", O_RDONLY, 0, sub {	366	aio_open "/etc/passwd", IO::AIO::O_RDONLY, 0, sub {
313	if ($_[0]) {	367	if ($_[0]) {
314	print "open successful, fh is $_[0]\n";	368	print "open successful, fh is $_[0]\n";
315	...	369	...
316	} else {	370	} else {
317	die "open failed: $!\n";	371	die "open failed: $!\n";
318	}	372	}
319	};	373	};
320		374
		375	In addition to all the common open modes/flags (C<O_RDONLY>, C<O_WRONLY>,
		376	C<O_RDWR>, C<O_CREAT>, C<O_TRUNC>, C<O_EXCL> and C<O_APPEND>), the
		377	following POSIX and non-POSIX constants are available (missing ones on
		378	your system are, as usual, C<0>):
		379
		380	C<O_ASYNC>, C<O_DIRECT>, C<O_NOATIME>, C<O_CLOEXEC>, C<O_NOCTTY>, C<O_NOFOLLOW>,
		381	C<O_NONBLOCK>, C<O_EXEC>, C<O_SEARCH>, C<O_DIRECTORY>, C<O_DSYNC>,
		382	C<O_RSYNC>, C<O_SYNC> and C<O_TTY_INIT>.
		383
321		384
322	=item aio_close $fh, $callback->($status)	385	=item aio_close $fh, $callback->($status)
323		386
324	Asynchronously close a file and call the callback with the result	387	Asynchronously close a file and call the callback with the result
325	code.	388	code.
…		…
375		438
376	Tries to copy C<$length> bytes from C<$in_fh> to C<$out_fh>. It starts	439	Tries to copy C<$length> bytes from C<$in_fh> to C<$out_fh>. It starts
377	reading at byte offset C<$in_offset>, and starts writing at the current	440	reading at byte offset C<$in_offset>, and starts writing at the current
378	file offset of C<$out_fh>. Because of that, it is not safe to issue more	441	file offset of C<$out_fh>. Because of that, it is not safe to issue more
379	than one C<aio_sendfile> per C<$out_fh>, as they will interfere with each	442	than one C<aio_sendfile> per C<$out_fh>, as they will interfere with each
380	other.	443	other. The same C<$in_fh> works fine though, as this function does not
		444	move or use the file offset of C<$in_fh>.
381		445
		446	Please note that C<aio_sendfile> can read more bytes from C<$in_fh> than
		447	are written, and there is no way to find out how many more bytes have been
		448	read from C<aio_sendfile> alone, as C<aio_sendfile> only provides the
		449	number of bytes written to C<$out_fh>. Only if the result value equals
		450	C<$length> one can assume that C<$length> bytes have been read.
		451
		452	Unlike with other C<aio_> functions, it makes a lot of sense to use
		453	C<aio_sendfile> on non-blocking sockets, as long as one end (typically
		454	the C<$in_fh>) is a file - the file I/O will then be asynchronous, while
		455	the socket I/O will be non-blocking. Note, however, that you can run
		456	into a trap where C<aio_sendfile> reads some data with readahead, then
		457	fails to write all data, and when the socket is ready the next time, the
		458	data in the cache is already lost, forcing C<aio_sendfile> to again hit
		459	the disk. Explicit C<aio_read> + C<aio_write> let's you better control
		460	resource usage.
		461
382	This call tries to make use of a native C<sendfile> syscall to provide	462	This call tries to make use of a native C<sendfile>-like syscall to
383	zero-copy operation. For this to work, C<$out_fh> should refer to a	463	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.	464	a socket, and C<$in_fh> should refer to an mmap'able file.
385		465
386	If a native sendfile cannot be found or it fails with C<ENOSYS>,	466	If a native sendfile cannot be found or it fails with C<ENOSYS>,
387	C<ENOTSUP>, C<EOPNOTSUPP>, C<EAFNOSUPPORT>, C<EPROTOTYPE> or C<ENOTSOCK>,	467	C<EINVAL>, C<ENOTSUP>, C<EOPNOTSUPP>, C<EAFNOSUPPORT>, C<EPROTOTYPE> or
388	it will be emulated, so you can call C<aio_sendfile> on any type of	468	C<ENOTSOCK>, it will be emulated, so you can call C<aio_sendfile> on any
389	filehandle regardless of the limitations of the operating system.	469	type of filehandle regardless of the limitations of the operating system.
390		470
391	Please note, however, that C<aio_sendfile> can read more bytes from	471	As native sendfile syscalls (as practically any non-POSIX interface hacked
392	C<$in_fh> than are written, and there is no way to find out how many	472	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	473	on many systems, this implementation tries to work around some known bugs
394	provides the number of bytes written to C<$out_fh>. Only if the result	474	in Linux and FreeBSD kernels (probably others, too), but that might fail,
395	value equals C<$length> one can assume that C<$length> bytes have been	475	so you really really should check the return value of C<aio_sendfile> -
396	read.	476	fewre bytes than expected might have been transferred.
397		477
398		478
399	=item aio_readahead $fh,$offset,$length, $callback->($retval)	479	=item aio_readahead $fh,$offset,$length, $callback->($retval)
400		480
401	C<aio_readahead> populates the page cache with data from a file so that	481	C<aio_readahead> populates the page cache with data from a file so that
…		…
424		504
425	Currently, the stats are always 64-bit-stats, i.e. instead of returning an	505	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	506	error when stat'ing a large file, the results will be silently truncated
427	unless perl itself is compiled with large file support.	507	unless perl itself is compiled with large file support.
428		508
		509	To help interpret the mode and dev/rdev stat values, IO::AIO offers the
		510	following constants and functions (if not implemented, the constants will
		511	be C<0> and the functions will either C<croak> or fall back on traditional
		512	behaviour).
		513
		514	C<S_IFMT>, C<S_IFIFO>, C<S_IFCHR>, C<S_IFBLK>, C<S_IFLNK>, C<S_IFREG>,
		515	C<S_IFDIR>, C<S_IFWHT>, C<S_IFSOCK>, C<IO::AIO::major $dev_t>,
		516	C<IO::AIO::minor $dev_t>, C<IO::AIO::makedev $major, $minor>.
		517
429	Example: Print the length of F</etc/passwd>:	518	Example: Print the length of F</etc/passwd>:
430		519
431	aio_stat "/etc/passwd", sub {	520	aio_stat "/etc/passwd", sub {
432	$_[0] and die "stat failed: $!";	521	$_[0] and die "stat failed: $!";
433	print "size is ", -s _, "\n";	522	print "size is ", -s _, "\n";
434	};	523	};
435		524
436		525
		526	=item aio_statvfs $fh_or_path, $callback->($statvfs)
		527
		528	Works like the POSIX C<statvfs> or C<fstatvfs> syscalls, depending on
		529	whether a file handle or path was passed.
		530
		531	On success, the callback is passed a hash reference with the following
		532	members: C<bsize>, C<frsize>, C<blocks>, C<bfree>, C<bavail>, C<files>,
		533	C<ffree>, C<favail>, C<fsid>, C<flag> and C<namemax>. On failure, C<undef>
		534	is passed.
		535
		536	The following POSIX IO::AIO::ST_* constants are defined: C<ST_RDONLY> and
		537	C<ST_NOSUID>.
		538
		539	The following non-POSIX IO::AIO::ST_* flag masks are defined to
		540	their correct value when available, or to C<0> on systems that do
		541	not support them: C<ST_NODEV>, C<ST_NOEXEC>, C<ST_SYNCHRONOUS>,
		542	C<ST_MANDLOCK>, C<ST_WRITE>, C<ST_APPEND>, C<ST_IMMUTABLE>, C<ST_NOATIME>,
		543	C<ST_NODIRATIME> and C<ST_RELATIME>.
		544
		545	Example: stat C</wd> and dump out the data if successful.
		546
		547	aio_statvfs "/wd", sub {
		548	my $f = $_[0]
		549	or die "statvfs: $!";
		550
		551	use Data::Dumper;
		552	say Dumper $f;
		553	};
		554
		555	# result:
		556	{
		557	bsize => 1024,
		558	bfree => 4333064312,
		559	blocks => 10253828096,
		560	files => 2050765568,
		561	flag => 4096,
		562	favail => 2042092649,
		563	bavail => 4333064312,
		564	ffree => 2042092649,
		565	namemax => 255,
		566	frsize => 1024,
		567	fsid => 1810
		568	}
		569
		570
437	=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status)	571	=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
438		572
439	Works like perl's C<utime> function (including the special case of $atime	573	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	574	and $mtime being undef). Fractional times are supported if the underlying
441	syscalls support them.	575	syscalls support them.
…		…
489		623
490	The only (POSIX-) portable way of calling this function is:	624	The only (POSIX-) portable way of calling this function is:
491		625
492	aio_mknod $path, IO::AIO::S_IFIFO \| $mode, 0, sub { ...	626	aio_mknod $path, IO::AIO::S_IFIFO \| $mode, 0, sub { ...
493		627
		628	See C<aio_stat> for info about some potentially helpful extra constants
		629	and functions.
494		630
495	=item aio_link $srcpath, $dstpath, $callback->($status)	631	=item aio_link $srcpath, $dstpath, $callback->($status)
496		632
497	Asynchronously create a new link to the existing object at C<$srcpath> at	633	Asynchronously create a new link to the existing object at C<$srcpath> at
498	the path C<$dstpath> and call the callback with the result code.	634	the path C<$dstpath> and call the callback with the result code.
…		…
509	Asynchronously read the symlink specified by C<$path> and pass it to	645	Asynchronously read the symlink specified by C<$path> and pass it to
510	the callback. If an error occurs, nothing or undef gets passed to the	646	the callback. If an error occurs, nothing or undef gets passed to the
511	callback.	647	callback.
512		648
513		649
		650	=item aio_realpath $path, $callback->($path)
		651
		652	Asynchronously make the path absolute and resolve any symlinks in
		653	C<$path>. The resulting path only consists of directories (Same as
		654	L<Cwd::realpath>).
		655
		656	This request can be used to get the absolute path of the current working
		657	directory by passing it a path of F<.> (a single dot).
		658
		659
514	=item aio_rename $srcpath, $dstpath, $callback->($status)	660	=item aio_rename $srcpath, $dstpath, $callback->($status)
515		661
516	Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as	662	Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as
517	rename(2) and call the callback with the result code.	663	rename(2) and call the callback with the result code.
518		664
…		…
551		697
552	=over 4	698	=over 4
553		699
554	=item IO::AIO::READDIR_DENTS	700	=item IO::AIO::READDIR_DENTS
555		701
556	When this flag is off, then the callback gets an arrayref with of names	702	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	703	names only (as with C<aio_readdir>), otherwise it gets an arrayref with
558	C<[$name, $type, $inode]> arrayrefs, each describing a single directory	704	C<[$name, $type, $inode]> arrayrefs, each describing a single directory
559	entry in more detail.	705	entry in more detail.
560		706
561	C<$name> is the name of the entry.	707	C<$name> is the name of the entry.
562		708
…		…
575	systems that do not deliver the inode information.	721	systems that do not deliver the inode information.
576		722
577	=item IO::AIO::READDIR_DIRS_FIRST	723	=item IO::AIO::READDIR_DIRS_FIRST
578		724
579	When this flag is set, then the names will be returned in an order where	725	When this flag is set, then the names will be returned in an order where
580	likely directories come first. This is useful when you need to quickly	726	likely directories come first, in optimal stat order. This is useful when
581	find directories, or you want to find all directories while avoiding to	727	you need to quickly find directories, or you want to find all directories
582	stat() each entry.	728	while avoiding to stat() each entry.
583		729
584	If the system returns type information in readdir, then this is used	730	If the system returns type information in readdir, then this is used
585	to find directories directly. Otherwise, likely directories are files	731	to find directories directly. Otherwise, likely directories are names
586	beginning with ".", or otherwise files with no dots, of which files with	732	beginning with ".", or otherwise names with no dots, of which names with
587	short names are tried first.	733	short names are tried first.
588		734
589	=item IO::AIO::READDIR_STAT_ORDER	735	=item IO::AIO::READDIR_STAT_ORDER
590		736
591	When this flag is set, then the names will be returned in an order	737	When this flag is set, then the names will be returned in an order
…		…
736	if ($_[0] && $! == EXDEV) {	882	if ($_[0] && $! == EXDEV) {
737	aioreq_pri $pri;	883	aioreq_pri $pri;
738	add $grp aio_copy $src, $dst, sub {	884	add $grp aio_copy $src, $dst, sub {
739	$grp->result ($_[0]);	885	$grp->result ($_[0]);
740		886
741	if (!$_[0]) {	887	unless ($_[0]) {
742	aioreq_pri $pri;	888	aioreq_pri $pri;
743	add $grp aio_unlink $src;	889	add $grp aio_unlink $src;
744	}	890	}
745	};	891	};
746	} else {	892	} else {
…		…
994	}	1140	}
995		1141
996	=item aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)	1142	=item aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
997		1143
998	This is a rather advanced IO::AIO call, which only works on mmap(2)ed	1144	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	1145	scalars (see the C<IO::AIO::mmap> function, although it also works on data
		1146	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	1147	scalar must only be modified in-place while an aio operation is pending on
1001	pending on it).	1148	it).
1002		1149
1003	It calls the C<msync> function of your OS, if available, with the memory	1150	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	1151	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>	1152	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	1153	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	1164	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	1165	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	1166	C<IO::AIO::MT_MODIFY>, which modifies the memory page s(by reading and
1020	writing an octet from it, which dirties the page).	1167	writing an octet from it, which dirties the page).
1021		1168
		1169	=item aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status)
		1170
		1171	This is a rather advanced IO::AIO call, which works best on mmap(2)ed
		1172	scalars.
		1173
		1174	It reads in all the pages of the underlying storage into memory (if any)
		1175	and locks them, so they are not getting swapped/paged out or removed.
		1176
		1177	If C<$length> is undefined, then the scalar will be locked till the end.
		1178
		1179	On systems that do not implement C<mlock>, this function returns C<-1>
		1180	and sets errno to C<ENOSYS>.
		1181
		1182	Note that the corresponding C<munlock> is synchronous and is
		1183	documented under L<MISCELLANEOUS FUNCTIONS>.
		1184
		1185	Example: open a file, mmap and mlock it - both will be undone when
		1186	C<$data> gets destroyed.
		1187
		1188	open my $fh, "<", $path or die "$path: $!";
		1189	my $data;
		1190	IO::AIO::mmap $data, -s $fh, IO::AIO::PROT_READ, IO::AIO::MAP_SHARED, $fh;
		1191	aio_mlock $data; # mlock in background
		1192
		1193	=item aio_mlockall $flags, $callback->($status)
		1194
		1195	Calls the C<mlockall> function with the given C<$flags> (a combination of
		1196	C<IO::AIO::MCL_CURRENT> and C<IO::AIO::MCL_FUTURE>).
		1197
		1198	On systems that do not implement C<mlockall>, this function returns C<-1>
		1199	and sets errno to C<ENOSYS>.
		1200
		1201	Note that the corresponding C<munlockall> is synchronous and is
		1202	documented under L<MISCELLANEOUS FUNCTIONS>.
		1203
		1204	Example: asynchronously lock all current and future pages into memory.
		1205
		1206	aio_mlockall IO::AIO::MCL_FUTURE;
		1207
1022	=item aio_group $callback->(...)	1208	=item aio_group $callback->(...)
1023		1209
1024	This is a very special aio request: Instead of doing something, it is a	1210	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	1211	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	1212	many requests into a single, composite, request with a definite callback
…		…
1249		1435
1250	See C<poll_cb> for an example.	1436	See C<poll_cb> for an example.
1251		1437
1252	=item IO::AIO::poll_cb	1438	=item IO::AIO::poll_cb
1253		1439
1254	Process some outstanding events on the result pipe. You have to call this	1440	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	1441	this regularly. Returns C<0> if all events could be processed (or there
1256	returned earlier for whatever reason. Returns immediately when no events	1442	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	1443	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>.	1444	events processed depends on the settings of C<IO::AIO::max_poll_req> and
		1445	C<IO::AIO::max_poll_time>.
1259		1446
1260	If not all requests were processed for whatever reason, the filehandle	1447	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	1448	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.	1449	do anything special to have it called later.
1263		1450
		1451	Apart from calling C<IO::AIO::poll_cb> when the event filehandle becomes
		1452	ready, it can be beneficial to call this function from loops which submit
		1453	a lot of requests, to make sure the results get processed when they become
		1454	available and not just when the loop is finished and the event loop takes
		1455	over again. This function returns very fast when there are no outstanding
		1456	requests.
		1457
1264	Example: Install an Event watcher that automatically calls	1458	Example: Install an Event watcher that automatically calls
1265	IO::AIO::poll_cb with high priority (more examples can be found in the	1459	IO::AIO::poll_cb with high priority (more examples can be found in the
1266	SYNOPSIS section, at the top of this document):	1460	SYNOPSIS section, at the top of this document):
1267		1461
1268	Event->io (fd => IO::AIO::poll_fileno,	1462	Event->io (fd => IO::AIO::poll_fileno,
1269	poll => 'r', async => 1,	1463	poll => 'r', async => 1,
1270	cb => \&IO::AIO::poll_cb);	1464	cb => \&IO::AIO::poll_cb);
		1465
		1466	=item IO::AIO::poll_wait
		1467
		1468	If there are any outstanding requests and none of them in the result
		1469	phase, wait till the result filehandle becomes ready for reading (simply
		1470	does a C<select> on the filehandle. This is useful if you want to
		1471	synchronously wait for some requests to finish).
		1472
		1473	See C<nreqs> for an example.
		1474
		1475	=item IO::AIO::poll
		1476
		1477	Waits until some requests have been handled.
		1478
		1479	Returns the number of requests processed, but is otherwise strictly
		1480	equivalent to:
		1481
		1482	IO::AIO::poll_wait, IO::AIO::poll_cb
		1483
		1484	=item IO::AIO::flush
		1485
		1486	Wait till all outstanding AIO requests have been handled.
		1487
		1488	Strictly equivalent to:
		1489
		1490	IO::AIO::poll_wait, IO::AIO::poll_cb
		1491	while IO::AIO::nreqs;
1271		1492
1272	=item IO::AIO::max_poll_reqs $nreqs	1493	=item IO::AIO::max_poll_reqs $nreqs
1273		1494
1274	=item IO::AIO::max_poll_time $seconds	1495	=item IO::AIO::max_poll_time $seconds
1275		1496
…		…
1300	# use a low priority so other tasks have priority	1521	# use a low priority so other tasks have priority
1301	Event->io (fd => IO::AIO::poll_fileno,	1522	Event->io (fd => IO::AIO::poll_fileno,
1302	poll => 'r', nice => 1,	1523	poll => 'r', nice => 1,
1303	cb => &IO::AIO::poll_cb);	1524	cb => &IO::AIO::poll_cb);
1304		1525
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	1526	=back
1333		1527
1334	=head3 CONTROLLING THE NUMBER OF THREADS	1528	=head3 CONTROLLING THE NUMBER OF THREADS
1335		1529
1336	=over	1530	=over
…		…
1369		1563
1370	Under normal circumstances you don't need to call this function.	1564	Under normal circumstances you don't need to call this function.
1371		1565
1372	=item IO::AIO::max_idle $nthreads	1566	=item IO::AIO::max_idle $nthreads
1373		1567
1374	Limit the number of threads (default: 4) that are allowed to idle (i.e.,	1568	Limit the number of threads (default: 4) that are allowed to idle
1375	threads that did not get a request to process within 10 seconds). That	1569	(i.e., threads that did not get a request to process within the idle
1376	means if a thread becomes idle while C<$nthreads> other threads are also	1570	timeout (default: 10 seconds). That means if a thread becomes idle while
1377	idle, it will free its resources and exit.	1571	C<$nthreads> other threads are also idle, it will free its resources and
		1572	exit.
1378		1573
1379	This is useful when you allow a large number of threads (e.g. 100 or 1000)	1574	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	1575	to allow for extremely high load situations, but want to free resources
1381	under normal circumstances (1000 threads can easily consume 30MB of RAM).	1576	under normal circumstances (1000 threads can easily consume 30MB of RAM).
1382		1577
1383	The default is probably ok in most situations, especially if thread	1578	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	1579	creation is fast. If thread creation is very slow on your system you might
1385	want to use larger values.	1580	want to use larger values.
1386		1581
		1582	=item IO::AIO::idle_timeout $seconds
		1583
		1584	Sets the minimum idle timeout (default 10) after which worker threads are
		1585	allowed to exit. SEe C<IO::AIO::max_idle>.
		1586
1387	=item IO::AIO::max_outstanding $maxreqs	1587	=item IO::AIO::max_outstanding $maxreqs
		1588
		1589	Sets the maximum number of outstanding requests to C<$nreqs>. If
		1590	you do queue up more than this number of requests, the next call to
		1591	C<IO::AIO::poll_cb> (and other functions calling C<poll_cb>, such as
		1592	C<IO::AIO::flush> or C<IO::AIO::poll>) will block until the limit is no
		1593	longer exceeded.
		1594
		1595	In other words, this setting does not enforce a queue limit, but can be
		1596	used to make poll functions block if the limit is exceeded.
1388		1597
1389	This is a very bad function to use in interactive programs because it	1598	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	1599	blocks, and a bad way to reduce concurrency because it is inexact: Better
1391	use an C<aio_group> together with a feed callback.	1600	use an C<aio_group> together with a feed callback.
1392		1601
1393	Sets the maximum number of outstanding requests to C<$nreqs>. If you	1602	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	1603	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		1604
1398	The default value is very large, so there is no practical limit on the	1605	IO::AIO::max_outstanding 32;
1399	number of outstanding requests.
1400		1606
1401	You can still queue as many requests as you want. Therefore,	1607	for my $path (...) {
1402	C<max_outstanding> is mainly useful in simple scripts (with low values) or	1608	aio_stat $path , ...;
1403	as a stop gap to shield against fatal memory overflow (with large values).	1609	IO::AIO::poll_cb;
		1610	}
		1611
		1612	IO::AIO::flush;
		1613
		1614	The call to C<poll_cb> inside the loop will normally return instantly, but
		1615	as soon as more thna C<32> reqeusts are in-flight, it will block until
		1616	some requests have been handled. This keeps the loop from pushing a large
		1617	number of C<aio_stat> requests onto the queue.
		1618
		1619	The default value for C<max_outstanding> is very large, so there is no
		1620	practical limit on the number of outstanding requests.
1404		1621
1405	=back	1622	=back
1406		1623
1407	=head3 STATISTICAL INFORMATION	1624	=head3 STATISTICAL INFORMATION
1408		1625
…		…
1446		1663
1447	Returns the number of bytes copied, or C<-1> on error.	1664	Returns the number of bytes copied, or C<-1> on error.
1448		1665
1449	=item IO::AIO::fadvise $fh, $offset, $len, $advice	1666	=item IO::AIO::fadvise $fh, $offset, $len, $advice
1450		1667
1451	Simply calls the C<posix_fadvise> function (see it's	1668	Simply calls the C<posix_fadvise> function (see its
1452	manpage for details). The following advice constants are	1669	manpage for details). The following advice constants are
1453	avaiable: C<IO::AIO::FADV_NORMAL>, C<IO::AIO::FADV_SEQUENTIAL>,	1670	avaiable: C<IO::AIO::FADV_NORMAL>, C<IO::AIO::FADV_SEQUENTIAL>,
1454	C<IO::AIO::FADV_RANDOM>, C<IO::AIO::FADV_NOREUSE>,	1671	C<IO::AIO::FADV_RANDOM>, C<IO::AIO::FADV_NOREUSE>,
1455	C<IO::AIO::FADV_WILLNEED>, C<IO::AIO::FADV_DONTNEED>.	1672	C<IO::AIO::FADV_WILLNEED>, C<IO::AIO::FADV_DONTNEED>.
1456		1673
1457	On systems that do not implement C<posix_fadvise>, this function returns	1674	On systems that do not implement C<posix_fadvise>, this function returns
1458	ENOSYS, otherwise the return value of C<posix_fadvise>.	1675	ENOSYS, otherwise the return value of C<posix_fadvise>.
1459		1676
		1677	=item IO::AIO::madvise $scalar, $offset, $len, $advice
		1678
		1679	Simply calls the C<posix_madvise> function (see its
		1680	manpage for details). The following advice constants are
		1681	avaiable: C<IO::AIO::MADV_NORMAL>, C<IO::AIO::MADV_SEQUENTIAL>,
		1682	C<IO::AIO::MADV_RANDOM>, C<IO::AIO::MADV_WILLNEED>, C<IO::AIO::MADV_DONTNEED>.
		1683
		1684	On systems that do not implement C<posix_madvise>, this function returns
		1685	ENOSYS, otherwise the return value of C<posix_madvise>.
		1686
		1687	=item IO::AIO::mprotect $scalar, $offset, $len, $protect
		1688
		1689	Simply calls the C<mprotect> function on the preferably AIO::mmap'ed
		1690	$scalar (see its manpage for details). The following protect
		1691	constants are avaiable: C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_READ>,
		1692	C<IO::AIO::PROT_WRITE>, C<IO::AIO::PROT_EXEC>.
		1693
		1694	On systems that do not implement C<mprotect>, this function returns
		1695	ENOSYS, otherwise the return value of C<mprotect>.
		1696
		1697	=item IO::AIO::mmap $scalar, $length, $prot, $flags, $fh[, $offset]
		1698
		1699	Memory-maps a file (or anonymous memory range) and attaches it to the
		1700	given C<$scalar>, which will act like a string scalar.
		1701
		1702	The only operations allowed on the scalar are C<substr>/C<vec> that don't
		1703	change the string length, and most read-only operations such as copying it
		1704	or searching it with regexes and so on.
		1705
		1706	Anything else is unsafe and will, at best, result in memory leaks.
		1707
		1708	The memory map associated with the C<$scalar> is automatically removed
		1709	when the C<$scalar> is destroyed, or when the C<IO::AIO::mmap> or
		1710	C<IO::AIO::munmap> functions are called.
		1711
		1712	This calls the C<mmap>(2) function internally. See your system's manual
		1713	page for details on the C<$length>, C<$prot> and C<$flags> parameters.
		1714
		1715	The C<$length> must be larger than zero and smaller than the actual
		1716	filesize.
		1717
		1718	C<$prot> is a combination of C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_EXEC>,
		1719	C<IO::AIO::PROT_READ> and/or C<IO::AIO::PROT_WRITE>,
		1720
		1721	C<$flags> can be a combination of C<IO::AIO::MAP_SHARED> or
		1722	C<IO::AIO::MAP_PRIVATE>, or a number of system-specific flags (when
		1723	not available, the are defined as 0): C<IO::AIO::MAP_ANONYMOUS>
		1724	(which is set to C<MAP_ANON> if your system only provides this
		1725	constant), C<IO::AIO::MAP_HUGETLB>, C<IO::AIO::MAP_LOCKED>,
		1726	C<IO::AIO::MAP_NORESERVE>, C<IO::AIO::MAP_POPULATE> or
		1727	C<IO::AIO::MAP_NONBLOCK>
		1728
		1729	If C<$fh> is C<undef>, then a file descriptor of C<-1> is passed.
		1730
		1731	C<$offset> is the offset from the start of the file - it generally must be
		1732	a multiple of C<IO::AIO::PAGESIZE> and defaults to C<0>.
		1733
		1734	Example:
		1735
		1736	use Digest::MD5;
		1737	use IO::AIO;
		1738
		1739	open my $fh, "<verybigfile"
		1740	or die "$!";
		1741
		1742	IO::AIO::mmap my $data, -s $fh, IO::AIO::PROT_READ, IO::AIO::MAP_SHARED, $fh
		1743	or die "verybigfile: $!";
		1744
		1745	my $fast_md5 = md5 $data;
		1746
		1747	=item IO::AIO::munmap $scalar
		1748
		1749	Removes a previous mmap and undefines the C<$scalar>.
		1750
		1751	=item IO::AIO::munlock $scalar, $offset = 0, $length = undef
		1752
		1753	Calls the C<munlock> function, undoing the effects of a previous
		1754	C<aio_mlock> call (see its description for details).
		1755
		1756	=item IO::AIO::munlockall
		1757
		1758	Calls the C<munlockall> function.
		1759
		1760	On systems that do not implement C<munlockall>, this function returns
		1761	ENOSYS, otherwise the return value of C<munlockall>.
		1762
1460	=back	1763	=back
1461		1764
1462	=cut	1765	=cut
1463		1766
1464	min_parallel 8;	1767	min_parallel 8;
1465		1768
1466	END { flush }	1769	END { flush }
1467		1770
1468	1;	1771	1;
1469		1772
		1773	=head1 EVENT LOOP INTEGRATION
		1774
		1775	It is recommended to use L<AnyEvent::AIO> to integrate IO::AIO
		1776	automatically into many event loops:
		1777
		1778	# AnyEvent integration (EV, Event, Glib, Tk, POE, urxvt, pureperl...)
		1779	use AnyEvent::AIO;
		1780
		1781	You can also integrate IO::AIO manually into many event loops, here are
		1782	some examples of how to do this:
		1783
		1784	# EV integration
		1785	my $aio_w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb;
		1786
		1787	# Event integration
		1788	Event->io (fd => IO::AIO::poll_fileno,
		1789	poll => 'r',
		1790	cb => \&IO::AIO::poll_cb);
		1791
		1792	# Glib/Gtk2 integration
		1793	add_watch Glib::IO IO::AIO::poll_fileno,
		1794	in => sub { IO::AIO::poll_cb; 1 };
		1795
		1796	# Tk integration
		1797	Tk::Event::IO->fileevent (IO::AIO::poll_fileno, "",
		1798	readable => \&IO::AIO::poll_cb);
		1799
		1800	# Danga::Socket integration
		1801	Danga::Socket->AddOtherFds (IO::AIO::poll_fileno =>
		1802	\&IO::AIO::poll_cb);
		1803
1470	=head2 FORK BEHAVIOUR	1804	=head2 FORK BEHAVIOUR
1471		1805
1472	This module should do "the right thing" when the process using it forks:	1806	Usage of pthreads in a program changes the semantics of fork
		1807	considerably. Specifically, only async-safe functions can be called after
		1808	fork. Perl doesn't know about this, so in general, you cannot call fork
		1809	with defined behaviour in perl. IO::AIO uses pthreads, so this applies,
		1810	but many other extensions and (for inexplicable reasons) perl itself often
		1811	is linked against pthreads, so this limitation applies.
1473		1812
1474	Before the fork, IO::AIO enters a quiescent state where no requests	1813	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	1814	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	1815	the time of this writing (2011) only GNU/Linux supports these extensions
1477	request/result processing, while the child frees the request/result queue	1816	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		1817
1486	=head2 MEMORY USAGE	1818	=head2 MEMORY USAGE
1487		1819
1488	Per-request usage:	1820	Per-request usage:
1489		1821

Diff Legend

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

Comparing IO-AIO/AIO.pm (file contents): Revision 1.171 by root, Sat Jan 2 14:24:32 2010 UTC vs. Revision 1.203 by root, Thu Jul 7 22:36:18 2011 UTC

Diff Legend

Comparing IO-AIO/AIO.pm (file contents):
Revision 1.171 by root, Sat Jan 2 14:24:32 2010 UTC vs.
Revision 1.203 by root, Thu Jul 7 22:36:18 2011 UTC