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

Comparing IO-AIO/AIO.pm (file contents):
Revision 1.151 by root, Fri Jun 12 00:43:16 2009 UTC vs.
Revision 1.186 by root, Thu Dec 30 07:19:31 2010 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
…		…
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		30
31	# AnyEvent integration (EV, Event, Glib, Tk, POE, urxvt, pureperl...)
32	use AnyEvent::AIO;
33
34	# EV integration
35	my $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
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.	34	operating system supports. It is implemented as an interface to C<libeio>
		35	(L<http://software.schmorp.de/pkg/libeio.html>).
58		36
59	Asynchronous means that operations that can normally block your program	37	Asynchronous means that operations that can normally block your program
60	(e.g. reading from disk) will be done asynchronously: the operation	38	(e.g. reading from disk) will be done asynchronously: the operation
61	will still block, but you can do something else in the meantime. This	39	will still block, but you can do something else in the meantime. This
62	is extremely useful for programs that need to stay interactive even	40	is extremely useful for programs that need to stay interactive even
…		…
66	on a RAID volume or over NFS when you do a number of stat operations	44	on a RAID volume or over NFS when you do a number of stat operations
67	concurrently.	45	concurrently.
68		46
69	While most of this works on all types of file descriptors (for	47	While most of this works on all types of file descriptors (for
70	example sockets), using these functions on file descriptors that	48	example sockets), using these functions on file descriptors that
71	support nonblocking operation (again, sockets, pipes etc.) is very	49	support nonblocking operation (again, sockets, pipes etc.) is
72	inefficient. Use an event loop for that (such as the L<Event\|Event>	50	very inefficient. Use an event loop for that (such as the L<EV>
73	module): IO::AIO will naturally fit into such an event loop itself.	51	module): IO::AIO will naturally fit into such an event loop itself.
74		52
75	In this version, a number of threads are started that execute your	53	In this version, a number of threads are started that execute your
76	requests and signal their completion. You don't need thread support	54	requests and signal their completion. You don't need thread support
77	in perl, and the threads created by this module will not be visible	55	in perl, and the threads created by this module will not be visible
…		…
87	yourself, always call C<poll_cb> from within the same thread, or never	65	yourself, always call C<poll_cb> from within the same thread, or never
88	call C<poll_cb> (or other C<aio_> functions) recursively.	66	call C<poll_cb> (or other C<aio_> functions) recursively.
89		67
90	=head2 EXAMPLE	68	=head2 EXAMPLE
91		69
92	This is a simple example that uses the Event module and loads	70	This is a simple example that uses the EV module and loads
93	F</etc/passwd> asynchronously:	71	F</etc/passwd> asynchronously:
94		72
95	use Fcntl;	73	use Fcntl;
96	use Event;	74	use EV;
97	use IO::AIO;	75	use IO::AIO;
98		76
99	# register the IO::AIO callback with Event	77	# register the IO::AIO callback with EV
100	Event->io (fd => IO::AIO::poll_fileno,	78	my $aio_w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb;
101	poll => 'r',
102	cb => \&IO::AIO::poll_cb);
103		79
104	# queue the request to open /etc/passwd	80	# queue the request to open /etc/passwd
105	aio_open "/etc/passwd", O_RDONLY, 0, sub {	81	aio_open "/etc/passwd", IO::AIO::O_RDONLY, 0, sub {
106	my $fh = shift	82	my $fh = shift
107	or die "error while opening: $!";	83	or die "error while opening: $!";
108		84
109	# stat'ing filehandles is generally non-blocking	85	# stat'ing filehandles is generally non-blocking
110	my $size = -s $fh;	86	my $size = -s $fh;
…		…
119		95
120	# file contents now in $contents	96	# file contents now in $contents
121	print $contents;	97	print $contents;
122		98
123	# exit event loop and program	99	# exit event loop and program
124	Event::unloop;	100	EV::unloop;
125	};	101	};
126	};	102	};
127		103
128	# possibly queue up other requests, or open GUI windows,	104	# possibly queue up other requests, or open GUI windows,
129	# check for sockets etc. etc.	105	# check for sockets etc. etc.
130		106
131	# process events as long as there are some:	107	# process events as long as there are some:
132	Event::loop;	108	EV::loop;
133		109
134	=head1 REQUEST ANATOMY AND LIFETIME	110	=head1 REQUEST ANATOMY AND LIFETIME
135		111
136	Every C<aio_*> function creates a request. which is a C data structure not	112	Every C<aio_*> function creates a request. which is a C data structure not
137	directly visible to Perl.	113	directly visible to Perl.
…		…
187		163
188	package IO::AIO;	164	package IO::AIO;
189		165
190	use Carp ();	166	use Carp ();
191		167
192	no warnings;	168	use common::sense;
193	use strict 'vars';
194		169
195	use base 'Exporter';	170	use base 'Exporter';
196		171
197	BEGIN {	172	BEGIN {
198	our $VERSION = '3.2';	173	our $VERSION = '3.71';
199		174
200	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
201	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
202	aio_scandir aio_symlink aio_readlink aio_sync aio_fsync	177	aio_scandir aio_symlink aio_readlink aio_sync aio_fsync
203	aio_fdatasync aio_sync_file_range aio_pathsync aio_readahead	178	aio_fdatasync aio_sync_file_range aio_pathsync aio_readahead
204	aio_rename aio_link aio_move aio_copy aio_group	179	aio_rename aio_link aio_move aio_copy aio_group
205	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
206	aio_chmod aio_utime aio_truncate);	181	aio_chmod aio_utime aio_truncate
		182	aio_msync aio_mtouch aio_mlock aio_mlockall
		183	aio_statvfs);
207		184
208	our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice));	185	our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice));
209	our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush	186	our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush
210	min_parallel max_parallel max_idle	187	min_parallel max_parallel max_idle
211	nreqs nready npending nthreads	188	nreqs nready npending nthreads
212	max_poll_time max_poll_reqs);	189	max_poll_time max_poll_reqs
		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::max_outstanding $maxreqs
		264	IO::AIO::nreqs
		265	IO::AIO::nready
		266	IO::AIO::npending
		267
		268	IO::AIO::sendfile $ofh, $ifh, $offset, $count
		269	IO::AIO::fadvise $fh, $offset, $len, $advice
		270	IO::AIO::madvise $scalar, $offset, $length, $advice
		271	IO::AIO::mprotect $scalar, $offset, $length, $protect
		272	IO::AIO::munlock $scalar, $offset = 0, $length = undef
		273	IO::AIO::munlockall
223		274
224	=head2 AIO REQUEST FUNCTIONS	275	=head2 AIO REQUEST FUNCTIONS
225		276
226	All the C<aio_*> calls are more or less thin wrappers around the syscall	277	All the C<aio_*> calls are more or less thin wrappers around the syscall
227	with the same name (sans C<aio_>). The arguments are similar or identical,	278	with the same name (sans C<aio_>). The arguments are similar or identical,
…		…
307	by the umask in effect then the request is being executed, so better never	358	by the umask in effect then the request is being executed, so better never
308	change the umask.	359	change the umask.
309		360
310	Example:	361	Example:
311		362
312	aio_open "/etc/passwd", O_RDONLY, 0, sub {	363	aio_open "/etc/passwd", IO::AIO::O_RDONLY, 0, sub {
313	if ($_[0]) {	364	if ($_[0]) {
314	print "open successful, fh is $_[0]\n";	365	print "open successful, fh is $_[0]\n";
315	...	366	...
316	} else {	367	} else {
317	die "open failed: $!\n";	368	die "open failed: $!\n";
…		…
377	reading at byte offset C<$in_offset>, and starts writing at the current	428	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	429	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	430	than one C<aio_sendfile> per C<$out_fh>, as they will interfere with each
380	other.	431	other.
381		432
		433	Please note that C<aio_sendfile> can read more bytes from C<$in_fh> than
		434	are written, and there is no way to find out how many bytes have been read
		435	from C<aio_sendfile> alone, as C<aio_sendfile> only provides the number of
		436	bytes written to C<$out_fh>. Only if the result value equals C<$length>
		437	one can assume that C<$length> bytes have been read.
		438
		439	Unlike with other C<aio_> functions, it makes a lot of sense to use
		440	C<aio_sendfile> on non-blocking sockets, as long as one end (typically
		441	the C<$in_fh>) is a file - the file I/O will then be asynchronous, while
		442	the socket I/O will be non-blocking. Note, however, that you can run into
		443	a trap where C<aio_sendfile> reads some data with readahead, then fails
		444	to write all data, and when the socket is ready the next time, the data
		445	in the cache is already lost, forcing C<aio_sendfile> to again hit the
		446	disk. Explicit C<aio_read> + C<aio_write> let's you control resource usage
		447	much better.
		448
382	This call tries to make use of a native C<sendfile> syscall to provide	449	This call tries to make use of a native C<sendfile> syscall to provide
383	zero-copy operation. For this to work, C<$out_fh> should refer to a	450	zero-copy operation. For this to work, C<$out_fh> should refer to a
384	socket, and C<$in_fh> should refer to mmap'able file.	451	socket, and C<$in_fh> should refer to an mmap'able file.
385		452
386	If the native sendfile call fails or is not implemented, it will be	453	If a native sendfile cannot be found or it fails with C<ENOSYS>,
		454	C<ENOTSUP>, C<EOPNOTSUPP>, C<EAFNOSUPPORT>, C<EPROTOTYPE> or C<ENOTSOCK>,
387	emulated, so you can call C<aio_sendfile> on any type of filehandle	455	it will be emulated, so you can call C<aio_sendfile> on any type of
388	regardless of the limitations of the operating system.	456	filehandle regardless of the limitations of the operating system.
389
390	Please note, however, that C<aio_sendfile> can read more bytes from
391	C<$in_fh> than are written, and there is no way to find out how many
392	bytes have been read from C<aio_sendfile> alone, as C<aio_sendfile> only
393	provides the number of bytes written to C<$out_fh>. Only if the result
394	value equals C<$length> one can assume that C<$length> bytes have been
395	read.
396		457
397		458
398	=item aio_readahead $fh,$offset,$length, $callback->($retval)	459	=item aio_readahead $fh,$offset,$length, $callback->($retval)
399		460
400	C<aio_readahead> populates the page cache with data from a file so that	461	C<aio_readahead> populates the page cache with data from a file so that
…		…
431	$_[0] and die "stat failed: $!";	492	$_[0] and die "stat failed: $!";
432	print "size is ", -s _, "\n";	493	print "size is ", -s _, "\n";
433	};	494	};
434		495
435		496
		497	=item aio_statvfs $fh_or_path, $callback->($statvfs)
		498
		499	Works like the POSIX C<statvfs> or C<fstatvfs> syscalls, depending on
		500	whether a file handle or path was passed.
		501
		502	On success, the callback is passed a hash reference with the following
		503	members: C<bsize>, C<frsize>, C<blocks>, C<bfree>, C<bavail>, C<files>,
		504	C<ffree>, C<favail>, C<fsid>, C<flag> and C<namemax>. On failure, C<undef>
		505	is passed.
		506
		507	The following POSIX IO::AIO::ST_* constants are defined: C<ST_RDONLY> and
		508	C<ST_NOSUID>.
		509
		510	The following non-POSIX IO::AIO::ST_* flag masks are defined to
		511	their correct value when available, or to C<0> on systems that do
		512	not support them: C<ST_NODEV>, C<ST_NOEXEC>, C<ST_SYNCHRONOUS>,
		513	C<ST_MANDLOCK>, C<ST_WRITE>, C<ST_APPEND>, C<ST_IMMUTABLE>, C<ST_NOATIME>,
		514	C<ST_NODIRATIME> and C<ST_RELATIME>.
		515
		516	Example: stat C</wd> and dump out the data if successful.
		517
		518	aio_statvfs "/wd", sub {
		519	my $f = $_[0]
		520	or die "statvfs: $!";
		521
		522	use Data::Dumper;
		523	say Dumper $f;
		524	};
		525
		526	# result:
		527	{
		528	bsize => 1024,
		529	bfree => 4333064312,
		530	blocks => 10253828096,
		531	files => 2050765568,
		532	flag => 4096,
		533	favail => 2042092649,
		534	bavail => 4333064312,
		535	ffree => 2042092649,
		536	namemax => 255,
		537	frsize => 1024,
		538	fsid => 1810
		539	}
		540
		541
436	=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status)	542	=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
437		543
438	Works like perl's C<utime> function (including the special case of $atime	544	Works like perl's C<utime> function (including the special case of $atime
439	and $mtime being undef). Fractional times are supported if the underlying	545	and $mtime being undef). Fractional times are supported if the underlying
440	syscalls support them.	546	syscalls support them.
…		…
568	C<IO::AIO::DT_UNKNOWN> means just that: readdir does not know. If you need to	674	C<IO::AIO::DT_UNKNOWN> means just that: readdir does not know. If you need to
569	know, you have to run stat yourself. Also, for speed reasons, the C<$type>	675	know, you have to run stat yourself. Also, for speed reasons, the C<$type>
570	scalars are read-only: you can not modify them.	676	scalars are read-only: you can not modify them.
571		677
572	C<$inode> is the inode number (which might not be exact on systems with 64	678	C<$inode> is the inode number (which might not be exact on systems with 64
573	bit inode numbers and 32 bit perls). On systems that do not deliver the	679	bit inode numbers and 32 bit perls). This field has unspecified content on
574	inode information, this will always be zero.	680	systems that do not deliver the inode information.
575		681
576	=item IO::AIO::READDIR_DIRS_FIRST	682	=item IO::AIO::READDIR_DIRS_FIRST
577		683
578	When this flag is set, then the names will be returned in an order where	684	When this flag is set, then the names will be returned in an order where
579	likely directories come first. This is useful when you need to quickly	685	likely directories come first. This is useful when you need to quickly
…		…
635		741
636	=item aio_copy $srcpath, $dstpath, $callback->($status)	742	=item aio_copy $srcpath, $dstpath, $callback->($status)
637		743
638	Try to copy the I<file> (directories not supported as either source or	744	Try to copy the I<file> (directories not supported as either source or
639	destination) from C<$srcpath> to C<$dstpath> and call the callback with	745	destination) from C<$srcpath> to C<$dstpath> and call the callback with
640	the C<0> (error) or C<-1> ok.	746	a status of C<0> (ok) or C<-1> (error, see C<$!>).
641		747
642	This is a composite request that creates the destination file with	748	This is a composite request that creates the destination file with
643	mode 0200 and copies the contents of the source file into it using	749	mode 0200 and copies the contents of the source file into it using
644	C<aio_sendfile>, followed by restoring atime, mtime, access mode and	750	C<aio_sendfile>, followed by restoring atime, mtime, access mode and
645	uid/gid, in that order.	751	uid/gid, in that order.
…		…
657	my $grp = aio_group $cb;	763	my $grp = aio_group $cb;
658		764
659	aioreq_pri $pri;	765	aioreq_pri $pri;
660	add $grp aio_open $src, O_RDONLY, 0, sub {	766	add $grp aio_open $src, O_RDONLY, 0, sub {
661	if (my $src_fh = $_[0]) {	767	if (my $src_fh = $_[0]) {
662	my @stat = stat $src_fh; # hmm, might bock over nfs?	768	my @stat = stat $src_fh; # hmm, might block over nfs?
663		769
664	aioreq_pri $pri;	770	aioreq_pri $pri;
665	add $grp aio_open $dst, O_CREAT \| O_WRONLY \| O_TRUNC, 0200, sub {	771	add $grp aio_open $dst, O_CREAT \| O_WRONLY \| O_TRUNC, 0200, sub {
666	if (my $dst_fh = $_[0]) {	772	if (my $dst_fh = $_[0]) {
667	aioreq_pri $pri;	773	aioreq_pri $pri;
…		…
714		820
715	=item aio_move $srcpath, $dstpath, $callback->($status)	821	=item aio_move $srcpath, $dstpath, $callback->($status)
716		822
717	Try to move the I<file> (directories not supported as either source or	823	Try to move the I<file> (directories not supported as either source or
718	destination) from C<$srcpath> to C<$dstpath> and call the callback with	824	destination) from C<$srcpath> to C<$dstpath> and call the callback with
719	the C<0> (error) or C<-1> ok.	825	a status of C<0> (ok) or C<-1> (error, see C<$!>).
720		826
721	This is a composite request that tries to rename(2) the file first; if	827	This is a composite request that tries to rename(2) the file first; if
722	rename fails with C<EXDEV>, it copies the file with C<aio_copy> and, if	828	rename fails with C<EXDEV>, it copies the file with C<aio_copy> and, if
723	that is successful, unlinks the C<$srcpath>.	829	that is successful, unlinks the C<$srcpath>.
724		830
…		…
958	(E.g. rename). This might not work on all operating systems or have any	1064	(E.g. rename). This might not work on all operating systems or have any
959	specific effect, but usually it makes sure that directory changes get	1065	specific effect, but usually it makes sure that directory changes get
960	written to disc. It works for anything that can be opened for read-only,	1066	written to disc. It works for anything that can be opened for read-only,
961	not just directories.	1067	not just directories.
962		1068
		1069	Future versions of this function might fall back to other methods when
		1070	C<fsync> on the directory fails (such as calling C<sync>).
		1071
963	Passes C<0> when everything went ok, and C<-1> on error.	1072	Passes C<0> when everything went ok, and C<-1> on error.
964		1073
965	=cut	1074	=cut
966		1075
967	sub aio_pathsync($;$) {	1076	sub aio_pathsync($;$) {
…		…
987	};	1096	};
988		1097
989	$grp	1098	$grp
990	}	1099	}
991		1100
		1101	=item aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
		1102
		1103	This is a rather advanced IO::AIO call, which only works on mmap(2)ed
		1104	scalars (see the C<IO::AIO::mmap> function, although it also works on data
		1105	scalars managed by the L<Sys::Mmap> or L<Mmap> modules, note that the
		1106	scalar must only be modified in-place while an aio operation is pending on
		1107	it).
		1108
		1109	It calls the C<msync> function of your OS, if available, with the memory
		1110	area starting at C<$offset> in the string and ending C<$length> bytes
		1111	later. If C<$length> is negative, counts from the end, and if C<$length>
		1112	is C<undef>, then it goes till the end of the string. The flags can be
		1113	a combination of C<IO::AIO::MS_ASYNC>, C<IO::AIO::MS_INVALIDATE> and
		1114	C<IO::AIO::MS_SYNC>.
		1115
		1116	=item aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
		1117
		1118	This is a rather advanced IO::AIO call, which works best on mmap(2)ed
		1119	scalars.
		1120
		1121	It touches (reads or writes) all memory pages in the specified
		1122	range inside the scalar. All caveats and parameters are the same
		1123	as for C<aio_msync>, above, except for flags, which must be either
		1124	C<0> (which reads all pages and ensures they are instantiated) or
		1125	C<IO::AIO::MT_MODIFY>, which modifies the memory page s(by reading and
		1126	writing an octet from it, which dirties the page).
		1127
		1128	=item aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status)
		1129
		1130	This is a rather advanced IO::AIO call, which works best on mmap(2)ed
		1131	scalars.
		1132
		1133	It reads in all the pages of the underlying storage into memory (if any)
		1134	and locks them, so they are not getting swapped/paged out or removed.
		1135
		1136	If C<$length> is undefined, then the scalar will be locked till the end.
		1137
		1138	On systems that do not implement C<mlock>, this function returns C<-1>
		1139	and sets errno to C<ENOSYS>.
		1140
		1141	Note that the corresponding C<munlock> is synchronous and is
		1142	documented under L<MISCELLANEOUS FUNCTIONS>.
		1143
		1144	Example: open a file, mmap and mlock it - both will be undone when
		1145	C<$data> gets destroyed.
		1146
		1147	open my $fh, "<", $path or die "$path: $!";
		1148	my $data;
		1149	IO::AIO::mmap $data, -s $fh, IO::AIO::PROT_READ, IO::AIO::MAP_SHARED, $fh;
		1150	aio_mlock $data; # mlock in background
		1151
		1152	=item aio_mlockall $flags, $callback->($status)
		1153
		1154	Calls the C<mlockall> function with the given C<$flags> (a combination of
		1155	C<IO::AIO::MCL_CURRENT> and C<IO::AIO::MCL_FUTURE>).
		1156
		1157	On systems that do not implement C<mlockall>, this function returns C<-1>
		1158	and sets errno to C<ENOSYS>.
		1159
		1160	Note that the corresponding C<munlockall> is synchronous and is
		1161	documented under L<MISCELLANEOUS FUNCTIONS>.
		1162
		1163	Example: asynchronously lock all current and future pages into memory.
		1164
		1165	aio_mlockall IO::AIO::MCL_FUTURE;
		1166
992	=item aio_group $callback->(...)	1167	=item aio_group $callback->(...)
993		1168
994	This is a very special aio request: Instead of doing something, it is a	1169	This is a very special aio request: Instead of doing something, it is a
995	container for other aio requests, which is useful if you want to bundle	1170	container for other aio requests, which is useful if you want to bundle
996	many requests into a single, composite, request with a definite callback	1171	many requests into a single, composite, request with a definite callback
…		…
1131	=item $grp->cancel_subs	1306	=item $grp->cancel_subs
1132		1307
1133	Cancel all subrequests and clears any feeder, but not the group request	1308	Cancel all subrequests and clears any feeder, but not the group request
1134	itself. Useful when you queued a lot of events but got a result early.	1309	itself. Useful when you queued a lot of events but got a result early.
1135		1310
		1311	The group request will finish normally (you cannot add requests to the
		1312	group).
		1313
1136	=item $grp->result (...)	1314	=item $grp->result (...)
1137		1315
1138	Set the result value(s) that will be passed to the group callback when all	1316	Set the result value(s) that will be passed to the group callback when all
1139	subrequests have finished and set the groups errno to the current value	1317	subrequests have finished and set the groups errno to the current value
1140	of errno (just like calling C<errno> without an error number). By default,	1318	of errno (just like calling C<errno> without an error number). By default,
…		…
1208	=over 4	1386	=over 4
1209		1387
1210	=item $fileno = IO::AIO::poll_fileno	1388	=item $fileno = IO::AIO::poll_fileno
1211		1389
1212	Return the I<request result pipe file descriptor>. This filehandle must be	1390	Return the I<request result pipe file descriptor>. This filehandle must be
1213	polled for reading by some mechanism outside this module (e.g. Event or	1391	polled for reading by some mechanism outside this module (e.g. EV, Glib,
1214	select, see below or the SYNOPSIS). If the pipe becomes readable you have	1392	select and so on, see below or the SYNOPSIS). If the pipe becomes readable
1215	to call C<poll_cb> to check the results.	1393	you have to call C<poll_cb> to check the results.
1216		1394
1217	See C<poll_cb> for an example.	1395	See C<poll_cb> for an example.
1218		1396
1219	=item IO::AIO::poll_cb	1397	=item IO::AIO::poll_cb
1220		1398
…		…
1227	If not all requests were processed for whatever reason, the filehandle	1405	If not all requests were processed for whatever reason, the filehandle
1228	will still be ready when C<poll_cb> returns, so normally you don't have to	1406	will still be ready when C<poll_cb> returns, so normally you don't have to
1229	do anything special to have it called later.	1407	do anything special to have it called later.
1230		1408
1231	Example: Install an Event watcher that automatically calls	1409	Example: Install an Event watcher that automatically calls
1232	IO::AIO::poll_cb with high priority:	1410	IO::AIO::poll_cb with high priority (more examples can be found in the
		1411	SYNOPSIS section, at the top of this document):
1233		1412
1234	Event->io (fd => IO::AIO::poll_fileno,	1413	Event->io (fd => IO::AIO::poll_fileno,
1235	poll => 'r', async => 1,	1414	poll => 'r', async => 1,
1236	cb => \&IO::AIO::poll_cb);	1415	cb => \&IO::AIO::poll_cb);
		1416
		1417	=item IO::AIO::poll_wait
		1418
		1419	If there are any outstanding requests and none of them in the result
		1420	phase, wait till the result filehandle becomes ready for reading (simply
		1421	does a C<select> on the filehandle. This is useful if you want to
		1422	synchronously wait for some requests to finish).
		1423
		1424	See C<nreqs> for an example.
		1425
		1426	=item IO::AIO::poll
		1427
		1428	Waits until some requests have been handled.
		1429
		1430	Returns the number of requests processed, but is otherwise strictly
		1431	equivalent to:
		1432
		1433	IO::AIO::poll_wait, IO::AIO::poll_cb
		1434
		1435	=item IO::AIO::flush
		1436
		1437	Wait till all outstanding AIO requests have been handled.
		1438
		1439	Strictly equivalent to:
		1440
		1441	IO::AIO::poll_wait, IO::AIO::poll_cb
		1442	while IO::AIO::nreqs;
1237		1443
1238	=item IO::AIO::max_poll_reqs $nreqs	1444	=item IO::AIO::max_poll_reqs $nreqs
1239		1445
1240	=item IO::AIO::max_poll_time $seconds	1446	=item IO::AIO::max_poll_time $seconds
1241		1447
…		…
1266	# use a low priority so other tasks have priority	1472	# use a low priority so other tasks have priority
1267	Event->io (fd => IO::AIO::poll_fileno,	1473	Event->io (fd => IO::AIO::poll_fileno,
1268	poll => 'r', nice => 1,	1474	poll => 'r', nice => 1,
1269	cb => &IO::AIO::poll_cb);	1475	cb => &IO::AIO::poll_cb);
1270		1476
1271	=item IO::AIO::poll_wait
1272
1273	If there are any outstanding requests and none of them in the result
1274	phase, wait till the result filehandle becomes ready for reading (simply
1275	does a C<select> on the filehandle. This is useful if you want to
1276	synchronously wait for some requests to finish).
1277
1278	See C<nreqs> for an example.
1279
1280	=item IO::AIO::poll
1281
1282	Waits until some requests have been handled.
1283
1284	Returns the number of requests processed, but is otherwise strictly
1285	equivalent to:
1286
1287	IO::AIO::poll_wait, IO::AIO::poll_cb
1288
1289	=item IO::AIO::flush
1290
1291	Wait till all outstanding AIO requests have been handled.
1292
1293	Strictly equivalent to:
1294
1295	IO::AIO::poll_wait, IO::AIO::poll_cb
1296	while IO::AIO::nreqs;
1297
1298	=back	1477	=back
1299		1478
1300	=head3 CONTROLLING THE NUMBER OF THREADS	1479	=head3 CONTROLLING THE NUMBER OF THREADS
1301		1480
1302	=over	1481	=over
…		…
1394	Returns the number of requests currently in the pending state (executed,	1573	Returns the number of requests currently in the pending state (executed,
1395	but not yet processed by poll_cb).	1574	but not yet processed by poll_cb).
1396		1575
1397	=back	1576	=back
1398		1577
		1578	=head3 MISCELLANEOUS FUNCTIONS
		1579
		1580	IO::AIO implements some functions that might be useful, but are not
		1581	asynchronous.
		1582
		1583	=over 4
		1584
		1585	=item IO::AIO::sendfile $ofh, $ifh, $offset, $count
		1586
		1587	Calls the C<eio_sendfile_sync> function, which is like C<aio_sendfile>,
		1588	but is blocking (this makes most sense if you know the input data is
		1589	likely cached already and the output filehandle is set to non-blocking
		1590	operations).
		1591
		1592	Returns the number of bytes copied, or C<-1> on error.
		1593
		1594	=item IO::AIO::fadvise $fh, $offset, $len, $advice
		1595
		1596	Simply calls the C<posix_fadvise> function (see its
		1597	manpage for details). The following advice constants are
		1598	avaiable: C<IO::AIO::FADV_NORMAL>, C<IO::AIO::FADV_SEQUENTIAL>,
		1599	C<IO::AIO::FADV_RANDOM>, C<IO::AIO::FADV_NOREUSE>,
		1600	C<IO::AIO::FADV_WILLNEED>, C<IO::AIO::FADV_DONTNEED>.
		1601
		1602	On systems that do not implement C<posix_fadvise>, this function returns
		1603	ENOSYS, otherwise the return value of C<posix_fadvise>.
		1604
		1605	=item IO::AIO::madvise $scalar, $offset, $len, $advice
		1606
		1607	Simply calls the C<posix_madvise> function (see its
		1608	manpage for details). The following advice constants are
		1609	avaiable: C<IO::AIO::MADV_NORMAL>, C<IO::AIO::MADV_SEQUENTIAL>,
		1610	C<IO::AIO::MADV_RANDOM>, C<IO::AIO::MADV_WILLNEED>, C<IO::AIO::MADV_DONTNEED>.
		1611
		1612	On systems that do not implement C<posix_madvise>, this function returns
		1613	ENOSYS, otherwise the return value of C<posix_madvise>.
		1614
		1615	=item IO::AIO::mprotect $scalar, $offset, $len, $protect
		1616
		1617	Simply calls the C<mprotect> function on the preferably AIO::mmap'ed
		1618	$scalar (see its manpage for details). The following protect
		1619	constants are avaiable: C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_READ>,
		1620	C<IO::AIO::PROT_WRITE>, C<IO::AIO::PROT_EXEC>.
		1621
		1622	On systems that do not implement C<mprotect>, this function returns
		1623	ENOSYS, otherwise the return value of C<mprotect>.
		1624
		1625	=item IO::AIO::mmap $scalar, $length, $prot, $flags, $fh[, $offset]
		1626
		1627	Memory-maps a file (or anonymous memory range) and attaches it to the
		1628	given C<$scalar>, which will act like a string scalar.
		1629
		1630	The only operations allowed on the scalar are C<substr>/C<vec> that don't
		1631	change the string length, and most read-only operations such as copying it
		1632	or searching it with regexes and so on.
		1633
		1634	Anything else is unsafe and will, at best, result in memory leaks.
		1635
		1636	The memory map associated with the C<$scalar> is automatically removed
		1637	when the C<$scalar> is destroyed, or when the C<IO::AIO::mmap> or
		1638	C<IO::AIO::munmap> functions are called.
		1639
		1640	This calls the C<mmap>(2) function internally. See your system's manual
		1641	page for details on the C<$length>, C<$prot> and C<$flags> parameters.
		1642
		1643	The C<$length> must be larger than zero and smaller than the actual
		1644	filesize.
		1645
		1646	C<$prot> is a combination of C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_EXEC>,
		1647	C<IO::AIO::PROT_READ> and/or C<IO::AIO::PROT_WRITE>,
		1648
		1649	C<$flags> can be a combination of C<IO::AIO::MAP_SHARED> or
		1650	C<IO::AIO::MAP_PRIVATE>, or a number of system-specific flags (when
		1651	not available, the are defined as 0): C<IO::AIO::MAP_ANONYMOUS>
		1652	(which is set to C<MAP_ANON> if your system only provides this
		1653	constant), C<IO::AIO::MAP_HUGETLB>, C<IO::AIO::MAP_LOCKED>,
		1654	C<IO::AIO::MAP_NORESERVE>, C<IO::AIO::MAP_POPULATE> or
		1655	C<IO::AIO::MAP_NONBLOCK>
		1656
		1657	If C<$fh> is C<undef>, then a file descriptor of C<-1> is passed.
		1658
		1659	C<$offset> is the offset from the start of the file - it generally must be
		1660	a multiple of C<IO::AIO::PAGESIZE> and defaults to C<0>.
		1661
		1662	Example:
		1663
		1664	use Digest::MD5;
		1665	use IO::AIO;
		1666
		1667	open my $fh, "<verybigfile"
		1668	or die "$!";
		1669
		1670	IO::AIO::mmap my $data, -s $fh, IO::AIO::PROT_READ, IO::AIO::MAP_SHARED, $fh
		1671	or die "verybigfile: $!";
		1672
		1673	my $fast_md5 = md5 $data;
		1674
		1675	=item IO::AIO::munmap $scalar
		1676
		1677	Removes a previous mmap and undefines the C<$scalar>.
		1678
		1679	=item IO::AIO::munlock $scalar, $offset = 0, $length = undef
		1680
		1681	Calls the C<munlock> function, undoing the effects of a previous
		1682	C<aio_mlock> call (see its description for details).
		1683
		1684	=item IO::AIO::munlockall
		1685
		1686	Calls the C<munlockall> function.
		1687
		1688	On systems that do not implement C<munlockall>, this function returns
		1689	ENOSYS, otherwise the return value of C<munlockall>.
		1690
		1691	=back
		1692
1399	=cut	1693	=cut
1400		1694
1401	min_parallel 8;	1695	min_parallel 8;
1402		1696
1403	END { flush }	1697	END { flush }
1404		1698
1405	1;	1699	1;
		1700
		1701	=head1 EVENT LOOP INTEGRATION
		1702
		1703	It is recommended to use L<AnyEvent::AIO> to integrate IO::AIO
		1704	automatically into many event loops:
		1705
		1706	# AnyEvent integration (EV, Event, Glib, Tk, POE, urxvt, pureperl...)
		1707	use AnyEvent::AIO;
		1708
		1709	You can also integrate IO::AIO manually into many event loops, here are
		1710	some examples of how to do this:
		1711
		1712	# EV integration
		1713	my $aio_w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb;
		1714
		1715	# Event integration
		1716	Event->io (fd => IO::AIO::poll_fileno,
		1717	poll => 'r',
		1718	cb => \&IO::AIO::poll_cb);
		1719
		1720	# Glib/Gtk2 integration
		1721	add_watch Glib::IO IO::AIO::poll_fileno,
		1722	in => sub { IO::AIO::poll_cb; 1 };
		1723
		1724	# Tk integration
		1725	Tk::Event::IO->fileevent (IO::AIO::poll_fileno, "",
		1726	readable => \&IO::AIO::poll_cb);
		1727
		1728	# Danga::Socket integration
		1729	Danga::Socket->AddOtherFds (IO::AIO::poll_fileno =>
		1730	\&IO::AIO::poll_cb);
1406		1731
1407	=head2 FORK BEHAVIOUR	1732	=head2 FORK BEHAVIOUR
1408		1733
1409	This module should do "the right thing" when the process using it forks:	1734	This module should do "the right thing" when the process using it forks:
1410		1735

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Comparing IO-AIO/AIO.pm (file contents): Revision 1.151 by root, Fri Jun 12 00:43:16 2009 UTC vs. Revision 1.186 by root, Thu Dec 30 07:19:31 2010 UTC

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Comparing IO-AIO/AIO.pm (file contents):
Revision 1.151 by root, Fri Jun 12 00:43:16 2009 UTC vs.
Revision 1.186 by root, Thu Dec 30 07:19:31 2010 UTC