[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 1.197 by root, Wed Jun 29 10:49:35 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 = '3.9';
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_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_rename $srcpath, $dstpath, $callback->($status)
		228	aio_mkdir $pathname, $mode, $callback->($status)
		229	aio_rmdir $pathname, $callback->($status)
		230	aio_readdir $pathname, $callback->($entries)
		231	aio_readdirx $pathname, $flags, $callback->($entries, $flags)
		232	IO::AIO::READDIR_DENTS IO::AIO::READDIR_DIRS_FIRST
		233	IO::AIO::READDIR_STAT_ORDER IO::AIO::READDIR_FOUND_UNKNOWN
		234	aio_load $path, $data, $callback->($status)
		235	aio_copy $srcpath, $dstpath, $callback->($status)
		236	aio_move $srcpath, $dstpath, $callback->($status)
		237	aio_scandir $path, $maxreq, $callback->($dirs, $nondirs)
		238	aio_rmtree $path, $callback->($status)
		239	aio_sync $callback->($status)
		240	aio_fsync $fh, $callback->($status)
		241	aio_fdatasync $fh, $callback->($status)
		242	aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status)
		243	aio_pathsync $path, $callback->($status)
		244	aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
		245	aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
		246	aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status)
		247	aio_mlockall $flags, $callback->($status)
		248	aio_group $callback->(...)
		249	aio_nop $callback->()
		250
		251	$prev_pri = aioreq_pri [$pri]
		252	aioreq_nice $pri_adjust
		253
		254	IO::AIO::poll_wait
		255	IO::AIO::poll_cb
		256	IO::AIO::poll
		257	IO::AIO::flush
		258	IO::AIO::max_poll_reqs $nreqs
		259	IO::AIO::max_poll_time $seconds
		260	IO::AIO::min_parallel $nthreads
		261	IO::AIO::max_parallel $nthreads
		262	IO::AIO::max_idle $nthreads
		263	IO::AIO::idle_timeout $seconds
		264	IO::AIO::max_outstanding $maxreqs
		265	IO::AIO::nreqs
		266	IO::AIO::nready
		267	IO::AIO::npending
		268
		269	IO::AIO::sendfile $ofh, $ifh, $offset, $count
		270	IO::AIO::fadvise $fh, $offset, $len, $advice
		271	IO::AIO::madvise $scalar, $offset, $length, $advice
		272	IO::AIO::mprotect $scalar, $offset, $length, $protect
		273	IO::AIO::munlock $scalar, $offset = 0, $length = undef
		274	IO::AIO::munlockall
223		275
224	=head2 AIO REQUEST FUNCTIONS	276	=head2 AIO REQUEST FUNCTIONS
225		277
226	All the C<aio_*> calls are more or less thin wrappers around the syscall	278	All the C<aio_*> calls are more or less thin wrappers around the syscall
227	with the same name (sans C<aio_>). The arguments are similar or identical,	279	with the same name (sans C<aio_>). The arguments are similar or identical,
…		…
307	by the umask in effect then the request is being executed, so better never	359	by the umask in effect then the request is being executed, so better never
308	change the umask.	360	change the umask.
309		361
310	Example:	362	Example:
311		363
312	aio_open "/etc/passwd", O_RDONLY, 0, sub {	364	aio_open "/etc/passwd", IO::AIO::O_RDONLY, 0, sub {
313	if ($_[0]) {	365	if ($_[0]) {
314	print "open successful, fh is $_[0]\n";	366	print "open successful, fh is $_[0]\n";
315	...	367	...
316	} else {	368	} else {
317	die "open failed: $!\n";	369	die "open failed: $!\n";
318	}	370	}
319	};	371	};
320		372
		373	In addition to all the common open modes/flags (C<O_RDONLY>, C<O_WRONLY>,
		374	C<O_RDWR>, C<O_CREAT>, C<O_TRUNC>, C<O_EXCL> and C<O_APPEND>), the
		375	following POSIX and non-POSIX constants are available (missing ones on
		376	your system are, as usual, C<0>):
		377
		378	C<O_ASYNC>, C<O_DIRECT>, C<O_NOATIME>, C<O_CLOEXEC>, C<O_NOCTTY>, C<O_NOFOLLOW>,
		379	C<O_NONBLOCK>, C<O_EXEC>, C<O_SEARCH>, C<O_DIRECTORY>, C<O_DSYNC>,
		380	C<O_RSYNC>, C<O_SYNC> and C<O_TTY_INIT>.
		381
321		382
322	=item aio_close $fh, $callback->($status)	383	=item aio_close $fh, $callback->($status)
323		384
324	Asynchronously close a file and call the callback with the result	385	Asynchronously close a file and call the callback with the result
325	code.	386	code.
…		…
375		436
376	Tries to copy C<$length> bytes from C<$in_fh> to C<$out_fh>. It starts	437	Tries to copy C<$length> bytes from C<$in_fh> to C<$out_fh>. It starts
377	reading at byte offset C<$in_offset>, and starts writing at the current	438	reading at byte offset C<$in_offset>, and starts writing at the current
378	file offset of C<$out_fh>. Because of that, it is not safe to issue more	439	file offset of C<$out_fh>. Because of that, it is not safe to issue more
379	than one C<aio_sendfile> per C<$out_fh>, as they will interfere with each	440	than one C<aio_sendfile> per C<$out_fh>, as they will interfere with each
380	other.	441	other. The same C<$in_fh> works fine though, as this function does not
		442	move or use the file offset of C<$in_fh>.
381		443
		444	Please note that C<aio_sendfile> can read more bytes from C<$in_fh> than
		445	are written, and there is no way to find out how many more bytes have been
		446	read from C<aio_sendfile> alone, as C<aio_sendfile> only provides the
		447	number of bytes written to C<$out_fh>. Only if the result value equals
		448	C<$length> one can assume that C<$length> bytes have been read.
		449
		450	Unlike with other C<aio_> functions, it makes a lot of sense to use
		451	C<aio_sendfile> on non-blocking sockets, as long as one end (typically
		452	the C<$in_fh>) is a file - the file I/O will then be asynchronous, while
		453	the socket I/O will be non-blocking. Note, however, that you can run
		454	into a trap where C<aio_sendfile> reads some data with readahead, then
		455	fails to write all data, and when the socket is ready the next time, the
		456	data in the cache is already lost, forcing C<aio_sendfile> to again hit
		457	the disk. Explicit C<aio_read> + C<aio_write> let's you better control
		458	resource usage.
		459
382	This call tries to make use of a native C<sendfile> syscall to provide	460	This call tries to make use of a native C<sendfile>-like syscall to
383	zero-copy operation. For this to work, C<$out_fh> should refer to a	461	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.	462	a socket, and C<$in_fh> should refer to an mmap'able file.
385		463
386	If a native sendfile cannot be found or it fails with C<ENOSYS>,	464	If a native sendfile cannot be found or it fails with C<ENOSYS>,
387	C<ENOTSUP>, C<EOPNOTSUPP>, C<EAFNOSUPPORT>, C<EPROTOTYPE> or C<ENOTSOCK>,	465	C<EINVAL>, C<ENOTSUP>, C<EOPNOTSUPP>, C<EAFNOSUPPORT>, C<EPROTOTYPE> or
388	it will be emulated, so you can call C<aio_sendfile> on any type of	466	C<ENOTSOCK>, it will be emulated, so you can call C<aio_sendfile> on any
389	filehandle regardless of the limitations of the operating system.	467	type of filehandle regardless of the limitations of the operating system.
390		468
391	Please note, however, that C<aio_sendfile> can read more bytes from	469	As native sendfile syscalls (as practically any non-POSIX interface hacked
392	C<$in_fh> than are written, and there is no way to find out how many	470	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	471	on many systems, this implementation tries to work around some known bugs
394	provides the number of bytes written to C<$out_fh>. Only if the result	472	in Linux and FreeBSD kernels (probably others, too), but that might fail,
395	value equals C<$length> one can assume that C<$length> bytes have been	473	so you really really should check the return value of C<aio_sendfile> -
396	read.	474	fewre bytes than expected might have been transferred.
397		475
398		476
399	=item aio_readahead $fh,$offset,$length, $callback->($retval)	477	=item aio_readahead $fh,$offset,$length, $callback->($retval)
400		478
401	C<aio_readahead> populates the page cache with data from a file so that	479	C<aio_readahead> populates the page cache with data from a file so that
…		…
424		502
425	Currently, the stats are always 64-bit-stats, i.e. instead of returning an	503	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	504	error when stat'ing a large file, the results will be silently truncated
427	unless perl itself is compiled with large file support.	505	unless perl itself is compiled with large file support.
428		506
		507	To help interpret the mode and dev/rdev stat values, IO::AIO offers the
		508	following constants and functions (if not implemented, the constants will
		509	be C<0> and the functions will either C<croak> or fall back on traditional
		510	behaviour).
		511
		512	C<S_IFMT>, C<S_IFIFO>, C<S_IFCHR>, C<S_IFBLK>, C<S_IFLNK>, C<S_IFREG>,
		513	C<S_IFDIR>, C<S_IFWHT>, C<S_IFSOCK>, C<IO::AIO::major $dev_t>,
		514	C<IO::AIO::minor $dev_t>, C<IO::AIO::makedev $major, $minor>.
		515
429	Example: Print the length of F</etc/passwd>:	516	Example: Print the length of F</etc/passwd>:
430		517
431	aio_stat "/etc/passwd", sub {	518	aio_stat "/etc/passwd", sub {
432	$_[0] and die "stat failed: $!";	519	$_[0] and die "stat failed: $!";
433	print "size is ", -s _, "\n";	520	print "size is ", -s _, "\n";
434	};	521	};
435		522
436		523
		524	=item aio_statvfs $fh_or_path, $callback->($statvfs)
		525
		526	Works like the POSIX C<statvfs> or C<fstatvfs> syscalls, depending on
		527	whether a file handle or path was passed.
		528
		529	On success, the callback is passed a hash reference with the following
		530	members: C<bsize>, C<frsize>, C<blocks>, C<bfree>, C<bavail>, C<files>,
		531	C<ffree>, C<favail>, C<fsid>, C<flag> and C<namemax>. On failure, C<undef>
		532	is passed.
		533
		534	The following POSIX IO::AIO::ST_* constants are defined: C<ST_RDONLY> and
		535	C<ST_NOSUID>.
		536
		537	The following non-POSIX IO::AIO::ST_* flag masks are defined to
		538	their correct value when available, or to C<0> on systems that do
		539	not support them: C<ST_NODEV>, C<ST_NOEXEC>, C<ST_SYNCHRONOUS>,
		540	C<ST_MANDLOCK>, C<ST_WRITE>, C<ST_APPEND>, C<ST_IMMUTABLE>, C<ST_NOATIME>,
		541	C<ST_NODIRATIME> and C<ST_RELATIME>.
		542
		543	Example: stat C</wd> and dump out the data if successful.
		544
		545	aio_statvfs "/wd", sub {
		546	my $f = $_[0]
		547	or die "statvfs: $!";
		548
		549	use Data::Dumper;
		550	say Dumper $f;
		551	};
		552
		553	# result:
		554	{
		555	bsize => 1024,
		556	bfree => 4333064312,
		557	blocks => 10253828096,
		558	files => 2050765568,
		559	flag => 4096,
		560	favail => 2042092649,
		561	bavail => 4333064312,
		562	ffree => 2042092649,
		563	namemax => 255,
		564	frsize => 1024,
		565	fsid => 1810
		566	}
		567
		568
437	=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status)	569	=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
438		570
439	Works like perl's C<utime> function (including the special case of $atime	571	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	572	and $mtime being undef). Fractional times are supported if the underlying
441	syscalls support them.	573	syscalls support them.
…		…
489		621
490	The only (POSIX-) portable way of calling this function is:	622	The only (POSIX-) portable way of calling this function is:
491		623
492	aio_mknod $path, IO::AIO::S_IFIFO \| $mode, 0, sub { ...	624	aio_mknod $path, IO::AIO::S_IFIFO \| $mode, 0, sub { ...
493		625
		626	See C<aio_stat> for info about some potentially helpful extra constants
		627	and functions.
494		628
495	=item aio_link $srcpath, $dstpath, $callback->($status)	629	=item aio_link $srcpath, $dstpath, $callback->($status)
496		630
497	Asynchronously create a new link to the existing object at C<$srcpath> at	631	Asynchronously create a new link to the existing object at C<$srcpath> at
498	the path C<$dstpath> and call the callback with the result code.	632	the path C<$dstpath> and call the callback with the result code.
…		…
551		685
552	=over 4	686	=over 4
553		687
554	=item IO::AIO::READDIR_DENTS	688	=item IO::AIO::READDIR_DENTS
555		689
556	When this flag is off, then the callback gets an arrayref with of names	690	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	691	names only (as with C<aio_readdir>), otherwise it gets an arrayref with
558	C<[$name, $type, $inode]> arrayrefs, each describing a single directory	692	C<[$name, $type, $inode]> arrayrefs, each describing a single directory
559	entry in more detail.	693	entry in more detail.
560		694
561	C<$name> is the name of the entry.	695	C<$name> is the name of the entry.
562		696
…		…
575	systems that do not deliver the inode information.	709	systems that do not deliver the inode information.
576		710
577	=item IO::AIO::READDIR_DIRS_FIRST	711	=item IO::AIO::READDIR_DIRS_FIRST
578		712
579	When this flag is set, then the names will be returned in an order where	713	When this flag is set, then the names will be returned in an order where
580	likely directories come first. This is useful when you need to quickly	714	likely directories come first, in optimal stat order. This is useful when
581	find directories, or you want to find all directories while avoiding to	715	you need to quickly find directories, or you want to find all directories
582	stat() each entry.	716	while avoiding to stat() each entry.
583		717
584	If the system returns type information in readdir, then this is used	718	If the system returns type information in readdir, then this is used
585	to find directories directly. Otherwise, likely directories are files	719	to find directories directly. Otherwise, likely directories are names
586	beginning with ".", or otherwise files with no dots, of which files with	720	beginning with ".", or otherwise names with no dots, of which names with
587	short names are tried first.	721	short names are tried first.
588		722
589	=item IO::AIO::READDIR_STAT_ORDER	723	=item IO::AIO::READDIR_STAT_ORDER
590		724
591	When this flag is set, then the names will be returned in an order	725	When this flag is set, then the names will be returned in an order
…		…
736	if ($_[0] && $! == EXDEV) {	870	if ($_[0] && $! == EXDEV) {
737	aioreq_pri $pri;	871	aioreq_pri $pri;
738	add $grp aio_copy $src, $dst, sub {	872	add $grp aio_copy $src, $dst, sub {
739	$grp->result ($_[0]);	873	$grp->result ($_[0]);
740		874
741	if (!$_[0]) {	875	unless ($_[0]) {
742	aioreq_pri $pri;	876	aioreq_pri $pri;
743	add $grp aio_unlink $src;	877	add $grp aio_unlink $src;
744	}	878	}
745	};	879	};
746	} else {	880	} else {
…		…
994	}	1128	}
995		1129
996	=item aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)	1130	=item aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
997		1131
998	This is a rather advanced IO::AIO call, which only works on mmap(2)ed	1132	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	1133	scalars (see the C<IO::AIO::mmap> function, although it also works on data
		1134	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	1135	scalar must only be modified in-place while an aio operation is pending on
1001	pending on it).	1136	it).
1002		1137
1003	It calls the C<msync> function of your OS, if available, with the memory	1138	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	1139	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>	1140	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	1141	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	1152	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	1153	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	1154	C<IO::AIO::MT_MODIFY>, which modifies the memory page s(by reading and
1020	writing an octet from it, which dirties the page).	1155	writing an octet from it, which dirties the page).
1021		1156
		1157	=item aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status)
		1158
		1159	This is a rather advanced IO::AIO call, which works best on mmap(2)ed
		1160	scalars.
		1161
		1162	It reads in all the pages of the underlying storage into memory (if any)
		1163	and locks them, so they are not getting swapped/paged out or removed.
		1164
		1165	If C<$length> is undefined, then the scalar will be locked till the end.
		1166
		1167	On systems that do not implement C<mlock>, this function returns C<-1>
		1168	and sets errno to C<ENOSYS>.
		1169
		1170	Note that the corresponding C<munlock> is synchronous and is
		1171	documented under L<MISCELLANEOUS FUNCTIONS>.
		1172
		1173	Example: open a file, mmap and mlock it - both will be undone when
		1174	C<$data> gets destroyed.
		1175
		1176	open my $fh, "<", $path or die "$path: $!";
		1177	my $data;
		1178	IO::AIO::mmap $data, -s $fh, IO::AIO::PROT_READ, IO::AIO::MAP_SHARED, $fh;
		1179	aio_mlock $data; # mlock in background
		1180
		1181	=item aio_mlockall $flags, $callback->($status)
		1182
		1183	Calls the C<mlockall> function with the given C<$flags> (a combination of
		1184	C<IO::AIO::MCL_CURRENT> and C<IO::AIO::MCL_FUTURE>).
		1185
		1186	On systems that do not implement C<mlockall>, this function returns C<-1>
		1187	and sets errno to C<ENOSYS>.
		1188
		1189	Note that the corresponding C<munlockall> is synchronous and is
		1190	documented under L<MISCELLANEOUS FUNCTIONS>.
		1191
		1192	Example: asynchronously lock all current and future pages into memory.
		1193
		1194	aio_mlockall IO::AIO::MCL_FUTURE;
		1195
1022	=item aio_group $callback->(...)	1196	=item aio_group $callback->(...)
1023		1197
1024	This is a very special aio request: Instead of doing something, it is a	1198	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	1199	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	1200	many requests into a single, composite, request with a definite callback
…		…
1249		1423
1250	See C<poll_cb> for an example.	1424	See C<poll_cb> for an example.
1251		1425
1252	=item IO::AIO::poll_cb	1426	=item IO::AIO::poll_cb
1253		1427
1254	Process some outstanding events on the result pipe. You have to call this	1428	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	1429	this regularly. Returns C<0> if all events could be processed (or there
1256	returned earlier for whatever reason. Returns immediately when no events	1430	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	1431	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>.	1432	events processed depends on the settings of C<IO::AIO::max_poll_req> and
		1433	C<IO::AIO::max_poll_time>.
1259		1434
1260	If not all requests were processed for whatever reason, the filehandle	1435	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	1436	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.	1437	do anything special to have it called later.
1263		1438
		1439	Apart from calling C<IO::AIO::poll_cb> when the event filehandle becomes
		1440	ready, it can be beneficial to call this function from loops which submit
		1441	a lot of requests, to make sure the results get processed when they become
		1442	available and not just when the loop is finished and the event loop takes
		1443	over again. This function returns very fast when there are no outstanding
		1444	requests.
		1445
1264	Example: Install an Event watcher that automatically calls	1446	Example: Install an Event watcher that automatically calls
1265	IO::AIO::poll_cb with high priority (more examples can be found in the	1447	IO::AIO::poll_cb with high priority (more examples can be found in the
1266	SYNOPSIS section, at the top of this document):	1448	SYNOPSIS section, at the top of this document):
1267		1449
1268	Event->io (fd => IO::AIO::poll_fileno,	1450	Event->io (fd => IO::AIO::poll_fileno,
1269	poll => 'r', async => 1,	1451	poll => 'r', async => 1,
1270	cb => \&IO::AIO::poll_cb);	1452	cb => \&IO::AIO::poll_cb);
		1453
		1454	=item IO::AIO::poll_wait
		1455
		1456	If there are any outstanding requests and none of them in the result
		1457	phase, wait till the result filehandle becomes ready for reading (simply
		1458	does a C<select> on the filehandle. This is useful if you want to
		1459	synchronously wait for some requests to finish).
		1460
		1461	See C<nreqs> for an example.
		1462
		1463	=item IO::AIO::poll
		1464
		1465	Waits until some requests have been handled.
		1466
		1467	Returns the number of requests processed, but is otherwise strictly
		1468	equivalent to:
		1469
		1470	IO::AIO::poll_wait, IO::AIO::poll_cb
		1471
		1472	=item IO::AIO::flush
		1473
		1474	Wait till all outstanding AIO requests have been handled.
		1475
		1476	Strictly equivalent to:
		1477
		1478	IO::AIO::poll_wait, IO::AIO::poll_cb
		1479	while IO::AIO::nreqs;
1271		1480
1272	=item IO::AIO::max_poll_reqs $nreqs	1481	=item IO::AIO::max_poll_reqs $nreqs
1273		1482
1274	=item IO::AIO::max_poll_time $seconds	1483	=item IO::AIO::max_poll_time $seconds
1275		1484
…		…
1300	# use a low priority so other tasks have priority	1509	# use a low priority so other tasks have priority
1301	Event->io (fd => IO::AIO::poll_fileno,	1510	Event->io (fd => IO::AIO::poll_fileno,
1302	poll => 'r', nice => 1,	1511	poll => 'r', nice => 1,
1303	cb => &IO::AIO::poll_cb);	1512	cb => &IO::AIO::poll_cb);
1304		1513
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	1514	=back
1333		1515
1334	=head3 CONTROLLING THE NUMBER OF THREADS	1516	=head3 CONTROLLING THE NUMBER OF THREADS
1335		1517
1336	=over	1518	=over
…		…
1369		1551
1370	Under normal circumstances you don't need to call this function.	1552	Under normal circumstances you don't need to call this function.
1371		1553
1372	=item IO::AIO::max_idle $nthreads	1554	=item IO::AIO::max_idle $nthreads
1373		1555
1374	Limit the number of threads (default: 4) that are allowed to idle (i.e.,	1556	Limit the number of threads (default: 4) that are allowed to idle
1375	threads that did not get a request to process within 10 seconds). That	1557	(i.e., threads that did not get a request to process within the idle
1376	means if a thread becomes idle while C<$nthreads> other threads are also	1558	timeout (default: 10 seconds). That means if a thread becomes idle while
1377	idle, it will free its resources and exit.	1559	C<$nthreads> other threads are also idle, it will free its resources and
		1560	exit.
1378		1561
1379	This is useful when you allow a large number of threads (e.g. 100 or 1000)	1562	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	1563	to allow for extremely high load situations, but want to free resources
1381	under normal circumstances (1000 threads can easily consume 30MB of RAM).	1564	under normal circumstances (1000 threads can easily consume 30MB of RAM).
1382		1565
1383	The default is probably ok in most situations, especially if thread	1566	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	1567	creation is fast. If thread creation is very slow on your system you might
1385	want to use larger values.	1568	want to use larger values.
1386		1569
		1570	=item IO::AIO::idle_timeout $seconds
		1571
		1572	Sets the minimum idle timeout (default 10) after which worker threads are
		1573	allowed to exit. SEe C<IO::AIO::max_idle>.
		1574
1387	=item IO::AIO::max_outstanding $maxreqs	1575	=item IO::AIO::max_outstanding $maxreqs
		1576
		1577	Sets the maximum number of outstanding requests to C<$nreqs>. If
		1578	you do queue up more than this number of requests, the next call to
		1579	C<IO::AIO::poll_cb> (and other functions calling C<poll_cb>, such as
		1580	C<IO::AIO::flush> or C<IO::AIO::poll>) will block until the limit is no
		1581	longer exceeded.
		1582
		1583	In other words, this setting does not enforce a queue limit, but can be
		1584	used to make poll functions block if the limit is exceeded.
1388		1585
1389	This is a very bad function to use in interactive programs because it	1586	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	1587	blocks, and a bad way to reduce concurrency because it is inexact: Better
1391	use an C<aio_group> together with a feed callback.	1588	use an C<aio_group> together with a feed callback.
1392		1589
1393	Sets the maximum number of outstanding requests to C<$nreqs>. If you	1590	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	1591	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		1592
1398	The default value is very large, so there is no practical limit on the	1593	IO::AIO::max_outstanding 32;
1399	number of outstanding requests.
1400		1594
1401	You can still queue as many requests as you want. Therefore,	1595	for my $path (...) {
1402	C<max_outstanding> is mainly useful in simple scripts (with low values) or	1596	aio_stat $path , ...;
1403	as a stop gap to shield against fatal memory overflow (with large values).	1597	IO::AIO::poll_cb;
		1598	}
		1599
		1600	IO::AIO::flush;
		1601
		1602	The call to C<poll_cb> inside the loop will normally return instantly, but
		1603	as soon as more thna C<32> reqeusts are in-flight, it will block until
		1604	some requests have been handled. This keeps the loop from pushing a large
		1605	number of C<aio_stat> requests onto the queue.
		1606
		1607	The default value for C<max_outstanding> is very large, so there is no
		1608	practical limit on the number of outstanding requests.
1404		1609
1405	=back	1610	=back
1406		1611
1407	=head3 STATISTICAL INFORMATION	1612	=head3 STATISTICAL INFORMATION
1408		1613
…		…
1446		1651
1447	Returns the number of bytes copied, or C<-1> on error.	1652	Returns the number of bytes copied, or C<-1> on error.
1448		1653
1449	=item IO::AIO::fadvise $fh, $offset, $len, $advice	1654	=item IO::AIO::fadvise $fh, $offset, $len, $advice
1450		1655
1451	Simply calls the C<posix_fadvise> function (see it's	1656	Simply calls the C<posix_fadvise> function (see its
1452	manpage for details). The following advice constants are	1657	manpage for details). The following advice constants are
1453	avaiable: C<IO::AIO::FADV_NORMAL>, C<IO::AIO::FADV_SEQUENTIAL>,	1658	avaiable: C<IO::AIO::FADV_NORMAL>, C<IO::AIO::FADV_SEQUENTIAL>,
1454	C<IO::AIO::FADV_RANDOM>, C<IO::AIO::FADV_NOREUSE>,	1659	C<IO::AIO::FADV_RANDOM>, C<IO::AIO::FADV_NOREUSE>,
1455	C<IO::AIO::FADV_WILLNEED>, C<IO::AIO::FADV_DONTNEED>.	1660	C<IO::AIO::FADV_WILLNEED>, C<IO::AIO::FADV_DONTNEED>.
1456		1661
1457	On systems that do not implement C<posix_fadvise>, this function returns	1662	On systems that do not implement C<posix_fadvise>, this function returns
1458	ENOSYS, otherwise the return value of C<posix_fadvise>.	1663	ENOSYS, otherwise the return value of C<posix_fadvise>.
1459		1664
		1665	=item IO::AIO::madvise $scalar, $offset, $len, $advice
		1666
		1667	Simply calls the C<posix_madvise> function (see its
		1668	manpage for details). The following advice constants are
		1669	avaiable: C<IO::AIO::MADV_NORMAL>, C<IO::AIO::MADV_SEQUENTIAL>,
		1670	C<IO::AIO::MADV_RANDOM>, C<IO::AIO::MADV_WILLNEED>, C<IO::AIO::MADV_DONTNEED>.
		1671
		1672	On systems that do not implement C<posix_madvise>, this function returns
		1673	ENOSYS, otherwise the return value of C<posix_madvise>.
		1674
		1675	=item IO::AIO::mprotect $scalar, $offset, $len, $protect
		1676
		1677	Simply calls the C<mprotect> function on the preferably AIO::mmap'ed
		1678	$scalar (see its manpage for details). The following protect
		1679	constants are avaiable: C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_READ>,
		1680	C<IO::AIO::PROT_WRITE>, C<IO::AIO::PROT_EXEC>.
		1681
		1682	On systems that do not implement C<mprotect>, this function returns
		1683	ENOSYS, otherwise the return value of C<mprotect>.
		1684
		1685	=item IO::AIO::mmap $scalar, $length, $prot, $flags, $fh[, $offset]
		1686
		1687	Memory-maps a file (or anonymous memory range) and attaches it to the
		1688	given C<$scalar>, which will act like a string scalar.
		1689
		1690	The only operations allowed on the scalar are C<substr>/C<vec> that don't
		1691	change the string length, and most read-only operations such as copying it
		1692	or searching it with regexes and so on.
		1693
		1694	Anything else is unsafe and will, at best, result in memory leaks.
		1695
		1696	The memory map associated with the C<$scalar> is automatically removed
		1697	when the C<$scalar> is destroyed, or when the C<IO::AIO::mmap> or
		1698	C<IO::AIO::munmap> functions are called.
		1699
		1700	This calls the C<mmap>(2) function internally. See your system's manual
		1701	page for details on the C<$length>, C<$prot> and C<$flags> parameters.
		1702
		1703	The C<$length> must be larger than zero and smaller than the actual
		1704	filesize.
		1705
		1706	C<$prot> is a combination of C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_EXEC>,
		1707	C<IO::AIO::PROT_READ> and/or C<IO::AIO::PROT_WRITE>,
		1708
		1709	C<$flags> can be a combination of C<IO::AIO::MAP_SHARED> or
		1710	C<IO::AIO::MAP_PRIVATE>, or a number of system-specific flags (when
		1711	not available, the are defined as 0): C<IO::AIO::MAP_ANONYMOUS>
		1712	(which is set to C<MAP_ANON> if your system only provides this
		1713	constant), C<IO::AIO::MAP_HUGETLB>, C<IO::AIO::MAP_LOCKED>,
		1714	C<IO::AIO::MAP_NORESERVE>, C<IO::AIO::MAP_POPULATE> or
		1715	C<IO::AIO::MAP_NONBLOCK>
		1716
		1717	If C<$fh> is C<undef>, then a file descriptor of C<-1> is passed.
		1718
		1719	C<$offset> is the offset from the start of the file - it generally must be
		1720	a multiple of C<IO::AIO::PAGESIZE> and defaults to C<0>.
		1721
		1722	Example:
		1723
		1724	use Digest::MD5;
		1725	use IO::AIO;
		1726
		1727	open my $fh, "<verybigfile"
		1728	or die "$!";
		1729
		1730	IO::AIO::mmap my $data, -s $fh, IO::AIO::PROT_READ, IO::AIO::MAP_SHARED, $fh
		1731	or die "verybigfile: $!";
		1732
		1733	my $fast_md5 = md5 $data;
		1734
		1735	=item IO::AIO::munmap $scalar
		1736
		1737	Removes a previous mmap and undefines the C<$scalar>.
		1738
		1739	=item IO::AIO::munlock $scalar, $offset = 0, $length = undef
		1740
		1741	Calls the C<munlock> function, undoing the effects of a previous
		1742	C<aio_mlock> call (see its description for details).
		1743
		1744	=item IO::AIO::munlockall
		1745
		1746	Calls the C<munlockall> function.
		1747
		1748	On systems that do not implement C<munlockall>, this function returns
		1749	ENOSYS, otherwise the return value of C<munlockall>.
		1750
1460	=back	1751	=back
1461		1752
1462	=cut	1753	=cut
1463		1754
1464	min_parallel 8;	1755	min_parallel 8;
1465		1756
1466	END { flush }	1757	END { flush }
1467		1758
1468	1;	1759	1;
1469		1760
		1761	=head1 EVENT LOOP INTEGRATION
		1762
		1763	It is recommended to use L<AnyEvent::AIO> to integrate IO::AIO
		1764	automatically into many event loops:
		1765
		1766	# AnyEvent integration (EV, Event, Glib, Tk, POE, urxvt, pureperl...)
		1767	use AnyEvent::AIO;
		1768
		1769	You can also integrate IO::AIO manually into many event loops, here are
		1770	some examples of how to do this:
		1771
		1772	# EV integration
		1773	my $aio_w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb;
		1774
		1775	# Event integration
		1776	Event->io (fd => IO::AIO::poll_fileno,
		1777	poll => 'r',
		1778	cb => \&IO::AIO::poll_cb);
		1779
		1780	# Glib/Gtk2 integration
		1781	add_watch Glib::IO IO::AIO::poll_fileno,
		1782	in => sub { IO::AIO::poll_cb; 1 };
		1783
		1784	# Tk integration
		1785	Tk::Event::IO->fileevent (IO::AIO::poll_fileno, "",
		1786	readable => \&IO::AIO::poll_cb);
		1787
		1788	# Danga::Socket integration
		1789	Danga::Socket->AddOtherFds (IO::AIO::poll_fileno =>
		1790	\&IO::AIO::poll_cb);
		1791
1470	=head2 FORK BEHAVIOUR	1792	=head2 FORK BEHAVIOUR
1471		1793
1472	This module should do "the right thing" when the process using it forks:	1794	Usage of pthreads in a program changes the semantics of fork
		1795	considerably. Specifically, only async-safe functions can be called after
		1796	fork. Perl doesn't know about this, so in general, you cannot call fork
		1797	with defined behaviour in perl. IO::AIO uses pthreads, so this applies,
		1798	but many other extensions and (for inexplicable reasons) perl itself often
		1799	is linked against pthreads, so this limitation applies.
1473		1800
1474	Before the fork, IO::AIO enters a quiescent state where no requests	1801	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	1802	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	1803	the time of this writing (2011) only GNU/Linux supports these extensions
1477	request/result processing, while the child frees the request/result queue	1804	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		1805
1486	=head2 MEMORY USAGE	1806	=head2 MEMORY USAGE
1487		1807
1488	Per-request usage:	1808	Per-request usage:
1489		1809

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 1.197 by root, Wed Jun 29 10:49:35 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 1.197 by root, Wed Jun 29 10:49:35 2011 UTC