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

Comparing IO-AIO/AIO.pm (file contents):
Revision 1.153 by root, Sat Jun 13 13:33:00 2009 UTC vs.
Revision 1.190 by root, Thu May 19 22:42:20 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
…		…
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 = '3.22';	173	our $VERSION = '3.8';
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 idle_timeout
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::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: $!\n";
…		…
377	reading at byte offset C<$in_offset>, and starts writing at the current	429	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	430	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	431	than one C<aio_sendfile> per C<$out_fh>, as they will interfere with each
380	other.	432	other.
381		433
		434	Please note that C<aio_sendfile> can read more bytes from C<$in_fh> than
		435	are written, and there is no way to find out how many bytes have been read
		436	from C<aio_sendfile> alone, as C<aio_sendfile> only provides the number of
		437	bytes written to C<$out_fh>. Only if the result value equals C<$length>
		438	one can assume that C<$length> bytes have been read.
		439
		440	Unlike with other C<aio_> functions, it makes a lot of sense to use
		441	C<aio_sendfile> on non-blocking sockets, as long as one end (typically
		442	the C<$in_fh>) is a file - the file I/O will then be asynchronous, while
		443	the socket I/O will be non-blocking. Note, however, that you can run into
		444	a trap where C<aio_sendfile> reads some data with readahead, then fails
		445	to write all data, and when the socket is ready the next time, the data
		446	in the cache is already lost, forcing C<aio_sendfile> to again hit the
		447	disk. Explicit C<aio_read> + C<aio_write> let's you control resource usage
		448	much better.
		449
382	This call tries to make use of a native C<sendfile> syscall to provide	450	This call tries to make use of a native C<sendfile> syscall to provide
383	zero-copy operation. For this to work, C<$out_fh> should refer to a	451	zero-copy operation. For this to work, C<$out_fh> should refer to a
384	socket, and C<$in_fh> should refer to mmap'able file.	452	socket, and C<$in_fh> should refer to an mmap'able file.
385		453
386	If the native sendfile call fails or is not implemented, it will be	454	If a native sendfile cannot be found or it fails with C<ENOSYS>,
		455	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	456	it will be emulated, so you can call C<aio_sendfile> on any type of
388	regardless of the limitations of the operating system.	457	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		458
397		459
398	=item aio_readahead $fh,$offset,$length, $callback->($retval)	460	=item aio_readahead $fh,$offset,$length, $callback->($retval)
399		461
400	C<aio_readahead> populates the page cache with data from a file so that	462	C<aio_readahead> populates the page cache with data from a file so that
…		…
423		485
424	Currently, the stats are always 64-bit-stats, i.e. instead of returning an	486	Currently, the stats are always 64-bit-stats, i.e. instead of returning an
425	error when stat'ing a large file, the results will be silently truncated	487	error when stat'ing a large file, the results will be silently truncated
426	unless perl itself is compiled with large file support.	488	unless perl itself is compiled with large file support.
427		489
		490	To help interpret the mode and dev/rdev stat values, IO::AIO offers the
		491	following constants and functions (if not implemented, the constants will
		492	be C<0> and the functions will either C<croak> or fall back on traditional
		493	behaviour).
		494
		495	C<S_IFMT>, C<S_IFIFO>, C<S_IFCHR>, C<S_IFBLK>, C<S_IFLNK>, C<S_IFREG>,
		496	C<S_IFDIR>, C<S_IFWHT>, C<S_IFSOCK>, C<IO::AIO::major $dev_t>,
		497	C<IO::AIO::minor $dev_t>, C<IO::AIO::makedev $major, $minor>.
		498
428	Example: Print the length of F</etc/passwd>:	499	Example: Print the length of F</etc/passwd>:
429		500
430	aio_stat "/etc/passwd", sub {	501	aio_stat "/etc/passwd", sub {
431	$_[0] and die "stat failed: $!";	502	$_[0] and die "stat failed: $!";
432	print "size is ", -s _, "\n";	503	print "size is ", -s _, "\n";
433	};	504	};
434		505
435		506
		507	=item aio_statvfs $fh_or_path, $callback->($statvfs)
		508
		509	Works like the POSIX C<statvfs> or C<fstatvfs> syscalls, depending on
		510	whether a file handle or path was passed.
		511
		512	On success, the callback is passed a hash reference with the following
		513	members: C<bsize>, C<frsize>, C<blocks>, C<bfree>, C<bavail>, C<files>,
		514	C<ffree>, C<favail>, C<fsid>, C<flag> and C<namemax>. On failure, C<undef>
		515	is passed.
		516
		517	The following POSIX IO::AIO::ST_* constants are defined: C<ST_RDONLY> and
		518	C<ST_NOSUID>.
		519
		520	The following non-POSIX IO::AIO::ST_* flag masks are defined to
		521	their correct value when available, or to C<0> on systems that do
		522	not support them: C<ST_NODEV>, C<ST_NOEXEC>, C<ST_SYNCHRONOUS>,
		523	C<ST_MANDLOCK>, C<ST_WRITE>, C<ST_APPEND>, C<ST_IMMUTABLE>, C<ST_NOATIME>,
		524	C<ST_NODIRATIME> and C<ST_RELATIME>.
		525
		526	Example: stat C</wd> and dump out the data if successful.
		527
		528	aio_statvfs "/wd", sub {
		529	my $f = $_[0]
		530	or die "statvfs: $!";
		531
		532	use Data::Dumper;
		533	say Dumper $f;
		534	};
		535
		536	# result:
		537	{
		538	bsize => 1024,
		539	bfree => 4333064312,
		540	blocks => 10253828096,
		541	files => 2050765568,
		542	flag => 4096,
		543	favail => 2042092649,
		544	bavail => 4333064312,
		545	ffree => 2042092649,
		546	namemax => 255,
		547	frsize => 1024,
		548	fsid => 1810
		549	}
		550
		551
436	=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status)	552	=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
437		553
438	Works like perl's C<utime> function (including the special case of $atime	554	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	555	and $mtime being undef). Fractional times are supported if the underlying
440	syscalls support them.	556	syscalls support them.
…		…
488		604
489	The only (POSIX-) portable way of calling this function is:	605	The only (POSIX-) portable way of calling this function is:
490		606
491	aio_mknod $path, IO::AIO::S_IFIFO \| $mode, 0, sub { ...	607	aio_mknod $path, IO::AIO::S_IFIFO \| $mode, 0, sub { ...
492		608
		609	See C<aio_stat> for info about some potentially helpful extra constants
		610	and functions.
493		611
494	=item aio_link $srcpath, $dstpath, $callback->($status)	612	=item aio_link $srcpath, $dstpath, $callback->($status)
495		613
496	Asynchronously create a new link to the existing object at C<$srcpath> at	614	Asynchronously create a new link to the existing object at C<$srcpath> at
497	the path C<$dstpath> and call the callback with the result code.	615	the path C<$dstpath> and call the callback with the result code.
…		…
550		668
551	=over 4	669	=over 4
552		670
553	=item IO::AIO::READDIR_DENTS	671	=item IO::AIO::READDIR_DENTS
554		672
555	When this flag is off, then the callback gets an arrayref with of names	673	When this flag is off, then the callback gets an arrayref consisting of
556	only (as with C<aio_readdir>), otherwise it gets an arrayref with	674	names only (as with C<aio_readdir>), otherwise it gets an arrayref with
557	C<[$name, $type, $inode]> arrayrefs, each describing a single directory	675	C<[$name, $type, $inode]> arrayrefs, each describing a single directory
558	entry in more detail.	676	entry in more detail.
559		677
560	C<$name> is the name of the entry.	678	C<$name> is the name of the entry.
561		679
…		…
568	C<IO::AIO::DT_UNKNOWN> means just that: readdir does not know. If you need to	686	C<IO::AIO::DT_UNKNOWN> means just that: readdir does not know. If you need to
569	know, you have to run stat yourself. Also, for speed reasons, the C<$type>	687	know, you have to run stat yourself. Also, for speed reasons, the C<$type>
570	scalars are read-only: you can not modify them.	688	scalars are read-only: you can not modify them.
571		689
572	C<$inode> is the inode number (which might not be exact on systems with 64	690	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	691	bit inode numbers and 32 bit perls). This field has unspecified content on
574	inode information, this will always be zero.	692	systems that do not deliver the inode information.
575		693
576	=item IO::AIO::READDIR_DIRS_FIRST	694	=item IO::AIO::READDIR_DIRS_FIRST
577		695
578	When this flag is set, then the names will be returned in an order where	696	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	697	likely directories come first. This is useful when you need to quickly
…		…
635		753
636	=item aio_copy $srcpath, $dstpath, $callback->($status)	754	=item aio_copy $srcpath, $dstpath, $callback->($status)
637		755
638	Try to copy the I<file> (directories not supported as either source or	756	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	757	destination) from C<$srcpath> to C<$dstpath> and call the callback with
640	the C<0> (error) or C<-1> ok.	758	a status of C<0> (ok) or C<-1> (error, see C<$!>).
641		759
642	This is a composite request that creates the destination file with	760	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	761	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	762	C<aio_sendfile>, followed by restoring atime, mtime, access mode and
645	uid/gid, in that order.	763	uid/gid, in that order.
…		…
657	my $grp = aio_group $cb;	775	my $grp = aio_group $cb;
658		776
659	aioreq_pri $pri;	777	aioreq_pri $pri;
660	add $grp aio_open $src, O_RDONLY, 0, sub {	778	add $grp aio_open $src, O_RDONLY, 0, sub {
661	if (my $src_fh = $_[0]) {	779	if (my $src_fh = $_[0]) {
662	my @stat = stat $src_fh; # hmm, might bock over nfs?	780	my @stat = stat $src_fh; # hmm, might block over nfs?
663		781
664	aioreq_pri $pri;	782	aioreq_pri $pri;
665	add $grp aio_open $dst, O_CREAT \| O_WRONLY \| O_TRUNC, 0200, sub {	783	add $grp aio_open $dst, O_CREAT \| O_WRONLY \| O_TRUNC, 0200, sub {
666	if (my $dst_fh = $_[0]) {	784	if (my $dst_fh = $_[0]) {
667	aioreq_pri $pri;	785	aioreq_pri $pri;
…		…
714		832
715	=item aio_move $srcpath, $dstpath, $callback->($status)	833	=item aio_move $srcpath, $dstpath, $callback->($status)
716		834
717	Try to move the I<file> (directories not supported as either source or	835	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	836	destination) from C<$srcpath> to C<$dstpath> and call the callback with
719	the C<0> (error) or C<-1> ok.	837	a status of C<0> (ok) or C<-1> (error, see C<$!>).
720		838
721	This is a composite request that tries to rename(2) the file first; if	839	This is a composite request that tries to rename(2) the file first; if
722	rename fails with C<EXDEV>, it copies the file with C<aio_copy> and, if	840	rename fails with C<EXDEV>, it copies the file with C<aio_copy> and, if
723	that is successful, unlinks the C<$srcpath>.	841	that is successful, unlinks the C<$srcpath>.
724		842
…		…
958	(E.g. rename). This might not work on all operating systems or have any	1076	(E.g. rename). This might not work on all operating systems or have any
959	specific effect, but usually it makes sure that directory changes get	1077	specific effect, but usually it makes sure that directory changes get
960	written to disc. It works for anything that can be opened for read-only,	1078	written to disc. It works for anything that can be opened for read-only,
961	not just directories.	1079	not just directories.
962		1080
		1081	Future versions of this function might fall back to other methods when
		1082	C<fsync> on the directory fails (such as calling C<sync>).
		1083
963	Passes C<0> when everything went ok, and C<-1> on error.	1084	Passes C<0> when everything went ok, and C<-1> on error.
964		1085
965	=cut	1086	=cut
966		1087
967	sub aio_pathsync($;$) {	1088	sub aio_pathsync($;$) {
…		…
987	};	1108	};
988		1109
989	$grp	1110	$grp
990	}	1111	}
991		1112
		1113	=item aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
		1114
		1115	This is a rather advanced IO::AIO call, which only works on mmap(2)ed
		1116	scalars (see the C<IO::AIO::mmap> function, although it also works on data
		1117	scalars managed by the L<Sys::Mmap> or L<Mmap> modules, note that the
		1118	scalar must only be modified in-place while an aio operation is pending on
		1119	it).
		1120
		1121	It calls the C<msync> function of your OS, if available, with the memory
		1122	area starting at C<$offset> in the string and ending C<$length> bytes
		1123	later. If C<$length> is negative, counts from the end, and if C<$length>
		1124	is C<undef>, then it goes till the end of the string. The flags can be
		1125	a combination of C<IO::AIO::MS_ASYNC>, C<IO::AIO::MS_INVALIDATE> and
		1126	C<IO::AIO::MS_SYNC>.
		1127
		1128	=item aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
		1129
		1130	This is a rather advanced IO::AIO call, which works best on mmap(2)ed
		1131	scalars.
		1132
		1133	It touches (reads or writes) all memory pages in the specified
		1134	range inside the scalar. All caveats and parameters are the same
		1135	as for C<aio_msync>, above, except for flags, which must be either
		1136	C<0> (which reads all pages and ensures they are instantiated) or
		1137	C<IO::AIO::MT_MODIFY>, which modifies the memory page s(by reading and
		1138	writing an octet from it, which dirties the page).
		1139
		1140	=item aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status)
		1141
		1142	This is a rather advanced IO::AIO call, which works best on mmap(2)ed
		1143	scalars.
		1144
		1145	It reads in all the pages of the underlying storage into memory (if any)
		1146	and locks them, so they are not getting swapped/paged out or removed.
		1147
		1148	If C<$length> is undefined, then the scalar will be locked till the end.
		1149
		1150	On systems that do not implement C<mlock>, this function returns C<-1>
		1151	and sets errno to C<ENOSYS>.
		1152
		1153	Note that the corresponding C<munlock> is synchronous and is
		1154	documented under L<MISCELLANEOUS FUNCTIONS>.
		1155
		1156	Example: open a file, mmap and mlock it - both will be undone when
		1157	C<$data> gets destroyed.
		1158
		1159	open my $fh, "<", $path or die "$path: $!";
		1160	my $data;
		1161	IO::AIO::mmap $data, -s $fh, IO::AIO::PROT_READ, IO::AIO::MAP_SHARED, $fh;
		1162	aio_mlock $data; # mlock in background
		1163
		1164	=item aio_mlockall $flags, $callback->($status)
		1165
		1166	Calls the C<mlockall> function with the given C<$flags> (a combination of
		1167	C<IO::AIO::MCL_CURRENT> and C<IO::AIO::MCL_FUTURE>).
		1168
		1169	On systems that do not implement C<mlockall>, this function returns C<-1>
		1170	and sets errno to C<ENOSYS>.
		1171
		1172	Note that the corresponding C<munlockall> is synchronous and is
		1173	documented under L<MISCELLANEOUS FUNCTIONS>.
		1174
		1175	Example: asynchronously lock all current and future pages into memory.
		1176
		1177	aio_mlockall IO::AIO::MCL_FUTURE;
		1178
992	=item aio_group $callback->(...)	1179	=item aio_group $callback->(...)
993		1180
994	This is a very special aio request: Instead of doing something, it is a	1181	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	1182	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	1183	many requests into a single, composite, request with a definite callback
…		…
1131	=item $grp->cancel_subs	1318	=item $grp->cancel_subs
1132		1319
1133	Cancel all subrequests and clears any feeder, but not the group request	1320	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.	1321	itself. Useful when you queued a lot of events but got a result early.
1135		1322
		1323	The group request will finish normally (you cannot add requests to the
		1324	group).
		1325
1136	=item $grp->result (...)	1326	=item $grp->result (...)
1137		1327
1138	Set the result value(s) that will be passed to the group callback when all	1328	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	1329	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,	1330	of errno (just like calling C<errno> without an error number). By default,
…		…
1208	=over 4	1398	=over 4
1209		1399
1210	=item $fileno = IO::AIO::poll_fileno	1400	=item $fileno = IO::AIO::poll_fileno
1211		1401
1212	Return the I<request result pipe file descriptor>. This filehandle must be	1402	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	1403	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	1404	select and so on, see below or the SYNOPSIS). If the pipe becomes readable
1215	to call C<poll_cb> to check the results.	1405	you have to call C<poll_cb> to check the results.
1216		1406
1217	See C<poll_cb> for an example.	1407	See C<poll_cb> for an example.
1218		1408
1219	=item IO::AIO::poll_cb	1409	=item IO::AIO::poll_cb
1220		1410
…		…
1227	If not all requests were processed for whatever reason, the filehandle	1417	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	1418	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.	1419	do anything special to have it called later.
1230		1420
1231	Example: Install an Event watcher that automatically calls	1421	Example: Install an Event watcher that automatically calls
1232	IO::AIO::poll_cb with high priority:	1422	IO::AIO::poll_cb with high priority (more examples can be found in the
		1423	SYNOPSIS section, at the top of this document):
1233		1424
1234	Event->io (fd => IO::AIO::poll_fileno,	1425	Event->io (fd => IO::AIO::poll_fileno,
1235	poll => 'r', async => 1,	1426	poll => 'r', async => 1,
1236	cb => \&IO::AIO::poll_cb);	1427	cb => \&IO::AIO::poll_cb);
		1428
		1429	=item IO::AIO::poll_wait
		1430
		1431	If there are any outstanding requests and none of them in the result
		1432	phase, wait till the result filehandle becomes ready for reading (simply
		1433	does a C<select> on the filehandle. This is useful if you want to
		1434	synchronously wait for some requests to finish).
		1435
		1436	See C<nreqs> for an example.
		1437
		1438	=item IO::AIO::poll
		1439
		1440	Waits until some requests have been handled.
		1441
		1442	Returns the number of requests processed, but is otherwise strictly
		1443	equivalent to:
		1444
		1445	IO::AIO::poll_wait, IO::AIO::poll_cb
		1446
		1447	=item IO::AIO::flush
		1448
		1449	Wait till all outstanding AIO requests have been handled.
		1450
		1451	Strictly equivalent to:
		1452
		1453	IO::AIO::poll_wait, IO::AIO::poll_cb
		1454	while IO::AIO::nreqs;
1237		1455
1238	=item IO::AIO::max_poll_reqs $nreqs	1456	=item IO::AIO::max_poll_reqs $nreqs
1239		1457
1240	=item IO::AIO::max_poll_time $seconds	1458	=item IO::AIO::max_poll_time $seconds
1241		1459
…		…
1266	# use a low priority so other tasks have priority	1484	# use a low priority so other tasks have priority
1267	Event->io (fd => IO::AIO::poll_fileno,	1485	Event->io (fd => IO::AIO::poll_fileno,
1268	poll => 'r', nice => 1,	1486	poll => 'r', nice => 1,
1269	cb => &IO::AIO::poll_cb);	1487	cb => &IO::AIO::poll_cb);
1270		1488
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	1489	=back
1299		1490
1300	=head3 CONTROLLING THE NUMBER OF THREADS	1491	=head3 CONTROLLING THE NUMBER OF THREADS
1301		1492
1302	=over	1493	=over
…		…
1335		1526
1336	Under normal circumstances you don't need to call this function.	1527	Under normal circumstances you don't need to call this function.
1337		1528
1338	=item IO::AIO::max_idle $nthreads	1529	=item IO::AIO::max_idle $nthreads
1339		1530
1340	Limit the number of threads (default: 4) that are allowed to idle (i.e.,	1531	Limit the number of threads (default: 4) that are allowed to idle
1341	threads that did not get a request to process within 10 seconds). That	1532	(i.e., threads that did not get a request to process within the idle
1342	means if a thread becomes idle while C<$nthreads> other threads are also	1533	timeout (default: 10 seconds). That means if a thread becomes idle while
1343	idle, it will free its resources and exit.	1534	C<$nthreads> other threads are also idle, it will free its resources and
		1535	exit.
1344		1536
1345	This is useful when you allow a large number of threads (e.g. 100 or 1000)	1537	This is useful when you allow a large number of threads (e.g. 100 or 1000)
1346	to allow for extremely high load situations, but want to free resources	1538	to allow for extremely high load situations, but want to free resources
1347	under normal circumstances (1000 threads can easily consume 30MB of RAM).	1539	under normal circumstances (1000 threads can easily consume 30MB of RAM).
1348		1540
1349	The default is probably ok in most situations, especially if thread	1541	The default is probably ok in most situations, especially if thread
1350	creation is fast. If thread creation is very slow on your system you might	1542	creation is fast. If thread creation is very slow on your system you might
1351	want to use larger values.	1543	want to use larger values.
		1544
		1545	=item IO::AIO::idle_timeout $seconds
		1546
		1547	Sets the minimum idle timeout (default 10) after which worker threads are
		1548	allowed to exit. SEe C<IO::AIO::max_idle>.
1352		1549
1353	=item IO::AIO::max_outstanding $maxreqs	1550	=item IO::AIO::max_outstanding $maxreqs
1354		1551
1355	This is a very bad function to use in interactive programs because it	1552	This is a very bad function to use in interactive programs because it
1356	blocks, and a bad way to reduce concurrency because it is inexact: Better	1553	blocks, and a bad way to reduce concurrency because it is inexact: Better
…		…
1394	Returns the number of requests currently in the pending state (executed,	1591	Returns the number of requests currently in the pending state (executed,
1395	but not yet processed by poll_cb).	1592	but not yet processed by poll_cb).
1396		1593
1397	=back	1594	=back
1398		1595
		1596	=head3 MISCELLANEOUS FUNCTIONS
		1597
		1598	IO::AIO implements some functions that might be useful, but are not
		1599	asynchronous.
		1600
		1601	=over 4
		1602
		1603	=item IO::AIO::sendfile $ofh, $ifh, $offset, $count
		1604
		1605	Calls the C<eio_sendfile_sync> function, which is like C<aio_sendfile>,
		1606	but is blocking (this makes most sense if you know the input data is
		1607	likely cached already and the output filehandle is set to non-blocking
		1608	operations).
		1609
		1610	Returns the number of bytes copied, or C<-1> on error.
		1611
		1612	=item IO::AIO::fadvise $fh, $offset, $len, $advice
		1613
		1614	Simply calls the C<posix_fadvise> function (see its
		1615	manpage for details). The following advice constants are
		1616	avaiable: C<IO::AIO::FADV_NORMAL>, C<IO::AIO::FADV_SEQUENTIAL>,
		1617	C<IO::AIO::FADV_RANDOM>, C<IO::AIO::FADV_NOREUSE>,
		1618	C<IO::AIO::FADV_WILLNEED>, C<IO::AIO::FADV_DONTNEED>.
		1619
		1620	On systems that do not implement C<posix_fadvise>, this function returns
		1621	ENOSYS, otherwise the return value of C<posix_fadvise>.
		1622
		1623	=item IO::AIO::madvise $scalar, $offset, $len, $advice
		1624
		1625	Simply calls the C<posix_madvise> function (see its
		1626	manpage for details). The following advice constants are
		1627	avaiable: C<IO::AIO::MADV_NORMAL>, C<IO::AIO::MADV_SEQUENTIAL>,
		1628	C<IO::AIO::MADV_RANDOM>, C<IO::AIO::MADV_WILLNEED>, C<IO::AIO::MADV_DONTNEED>.
		1629
		1630	On systems that do not implement C<posix_madvise>, this function returns
		1631	ENOSYS, otherwise the return value of C<posix_madvise>.
		1632
		1633	=item IO::AIO::mprotect $scalar, $offset, $len, $protect
		1634
		1635	Simply calls the C<mprotect> function on the preferably AIO::mmap'ed
		1636	$scalar (see its manpage for details). The following protect
		1637	constants are avaiable: C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_READ>,
		1638	C<IO::AIO::PROT_WRITE>, C<IO::AIO::PROT_EXEC>.
		1639
		1640	On systems that do not implement C<mprotect>, this function returns
		1641	ENOSYS, otherwise the return value of C<mprotect>.
		1642
		1643	=item IO::AIO::mmap $scalar, $length, $prot, $flags, $fh[, $offset]
		1644
		1645	Memory-maps a file (or anonymous memory range) and attaches it to the
		1646	given C<$scalar>, which will act like a string scalar.
		1647
		1648	The only operations allowed on the scalar are C<substr>/C<vec> that don't
		1649	change the string length, and most read-only operations such as copying it
		1650	or searching it with regexes and so on.
		1651
		1652	Anything else is unsafe and will, at best, result in memory leaks.
		1653
		1654	The memory map associated with the C<$scalar> is automatically removed
		1655	when the C<$scalar> is destroyed, or when the C<IO::AIO::mmap> or
		1656	C<IO::AIO::munmap> functions are called.
		1657
		1658	This calls the C<mmap>(2) function internally. See your system's manual
		1659	page for details on the C<$length>, C<$prot> and C<$flags> parameters.
		1660
		1661	The C<$length> must be larger than zero and smaller than the actual
		1662	filesize.
		1663
		1664	C<$prot> is a combination of C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_EXEC>,
		1665	C<IO::AIO::PROT_READ> and/or C<IO::AIO::PROT_WRITE>,
		1666
		1667	C<$flags> can be a combination of C<IO::AIO::MAP_SHARED> or
		1668	C<IO::AIO::MAP_PRIVATE>, or a number of system-specific flags (when
		1669	not available, the are defined as 0): C<IO::AIO::MAP_ANONYMOUS>
		1670	(which is set to C<MAP_ANON> if your system only provides this
		1671	constant), C<IO::AIO::MAP_HUGETLB>, C<IO::AIO::MAP_LOCKED>,
		1672	C<IO::AIO::MAP_NORESERVE>, C<IO::AIO::MAP_POPULATE> or
		1673	C<IO::AIO::MAP_NONBLOCK>
		1674
		1675	If C<$fh> is C<undef>, then a file descriptor of C<-1> is passed.
		1676
		1677	C<$offset> is the offset from the start of the file - it generally must be
		1678	a multiple of C<IO::AIO::PAGESIZE> and defaults to C<0>.
		1679
		1680	Example:
		1681
		1682	use Digest::MD5;
		1683	use IO::AIO;
		1684
		1685	open my $fh, "<verybigfile"
		1686	or die "$!";
		1687
		1688	IO::AIO::mmap my $data, -s $fh, IO::AIO::PROT_READ, IO::AIO::MAP_SHARED, $fh
		1689	or die "verybigfile: $!";
		1690
		1691	my $fast_md5 = md5 $data;
		1692
		1693	=item IO::AIO::munmap $scalar
		1694
		1695	Removes a previous mmap and undefines the C<$scalar>.
		1696
		1697	=item IO::AIO::munlock $scalar, $offset = 0, $length = undef
		1698
		1699	Calls the C<munlock> function, undoing the effects of a previous
		1700	C<aio_mlock> call (see its description for details).
		1701
		1702	=item IO::AIO::munlockall
		1703
		1704	Calls the C<munlockall> function.
		1705
		1706	On systems that do not implement C<munlockall>, this function returns
		1707	ENOSYS, otherwise the return value of C<munlockall>.
		1708
		1709	=back
		1710
1399	=cut	1711	=cut
1400		1712
1401	min_parallel 8;	1713	min_parallel 8;
1402		1714
1403	END { flush }	1715	END { flush }
1404		1716
1405	1;	1717	1;
		1718
		1719	=head1 EVENT LOOP INTEGRATION
		1720
		1721	It is recommended to use L<AnyEvent::AIO> to integrate IO::AIO
		1722	automatically into many event loops:
		1723
		1724	# AnyEvent integration (EV, Event, Glib, Tk, POE, urxvt, pureperl...)
		1725	use AnyEvent::AIO;
		1726
		1727	You can also integrate IO::AIO manually into many event loops, here are
		1728	some examples of how to do this:
		1729
		1730	# EV integration
		1731	my $aio_w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb;
		1732
		1733	# Event integration
		1734	Event->io (fd => IO::AIO::poll_fileno,
		1735	poll => 'r',
		1736	cb => \&IO::AIO::poll_cb);
		1737
		1738	# Glib/Gtk2 integration
		1739	add_watch Glib::IO IO::AIO::poll_fileno,
		1740	in => sub { IO::AIO::poll_cb; 1 };
		1741
		1742	# Tk integration
		1743	Tk::Event::IO->fileevent (IO::AIO::poll_fileno, "",
		1744	readable => \&IO::AIO::poll_cb);
		1745
		1746	# Danga::Socket integration
		1747	Danga::Socket->AddOtherFds (IO::AIO::poll_fileno =>
		1748	\&IO::AIO::poll_cb);
1406		1749
1407	=head2 FORK BEHAVIOUR	1750	=head2 FORK BEHAVIOUR
1408		1751
1409	This module should do "the right thing" when the process using it forks:	1752	This module should do "the right thing" when the process using it forks:
1410		1753

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Comparing IO-AIO/AIO.pm (file contents): Revision 1.153 by root, Sat Jun 13 13:33:00 2009 UTC vs. Revision 1.190 by root, Thu May 19 22:42:20 2011 UTC

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Comparing IO-AIO/AIO.pm (file contents):
Revision 1.153 by root, Sat Jun 13 13:33:00 2009 UTC vs.
Revision 1.190 by root, Thu May 19 22:42:20 2011 UTC