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

Comparing IO-AIO/AIO.pm (file contents):
Revision 1.107 by root, Fri Jun 1 05:52:59 2007 UTC vs.
Revision 1.176 by root, Sun Jan 10 23:05:11 2010 UTC

…		…
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
32	open my $fh, "<&=" . IO::AIO::poll_fileno or die "$!";
33	my $w = AnyEvent->io (fh => $fh, poll => 'r', cb => sub { IO::AIO::poll_cb });
34
35	# Event integration
36	Event->io (fd => IO::AIO::poll_fileno,
37	poll => 'r',
38	cb => \&IO::AIO::poll_cb);
39
40	# Glib/Gtk2 integration
41	add_watch Glib::IO IO::AIO::poll_fileno,
42	in => sub { IO::AIO::poll_cb; 1 };
43
44	# Tk integration
45	Tk::Event::IO->fileevent (IO::AIO::poll_fileno, "",
46	readable => \&IO::AIO::poll_cb);
47
48	# Danga::Socket integration
49	Danga::Socket->AddOtherFds (IO::AIO::poll_fileno =>
50	\&IO::AIO::poll_cb);
51
52	=head1 DESCRIPTION	31	=head1 DESCRIPTION
53		32
54	This module implements asynchronous I/O using whatever means your	33	This module implements asynchronous I/O using whatever means your
55	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>).
56		36
57	Asynchronous means that operations that can normally block your program	37	Asynchronous means that operations that can normally block your program
58	(e.g. reading from disk) will be done asynchronously: the operation	38	(e.g. reading from disk) will be done asynchronously: the operation
59	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
60	is extremely useful for programs that need to stay interactive even	40	is extremely useful for programs that need to stay interactive even
…		…
62	etc.), but can also be used to easily do operations in parallel that are	42	etc.), but can also be used to easily do operations in parallel that are
63	normally done sequentially, e.g. stat'ing many files, which is much faster	43	normally done sequentially, e.g. stat'ing many files, which is much faster
64	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
65	concurrently.	45	concurrently.
66		46
67	While most of this works on all types of file descriptors (for example	47	While most of this works on all types of file descriptors (for
68	sockets), using these functions on file descriptors that support	48	example sockets), using these functions on file descriptors that
69	nonblocking operation (again, sockets, pipes etc.) is very inefficient or	49	support nonblocking operation (again, sockets, pipes etc.) is
70	might not work (aio_read fails on sockets/pipes/fifos). Use an event loop	50	very inefficient. Use an event loop for that (such as the L<EV>
71	for that (such as the L<Event\|Event> module): IO::AIO will naturally fit	51	module): IO::AIO will naturally fit into such an event loop itself.
72	into such an event loop itself.
73		52
74	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
75	requests and signal their completion. You don't need thread support	54	requests and signal their completion. You don't need thread support
76	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
77	to perl. In the future, this module might make use of the native aio	56	to perl. In the future, this module might make use of the native aio
…		…
79	not well-supported or restricted (GNU/Linux doesn't allow them on normal	58	not well-supported or restricted (GNU/Linux doesn't allow them on normal
80	files currently, for example), and they would only support aio_read and	59	files currently, for example), and they would only support aio_read and
81	aio_write, so the remaining functionality would have to be implemented	60	aio_write, so the remaining functionality would have to be implemented
82	using threads anyway.	61	using threads anyway.
83		62
84	Although the module will work with in the presence of other (Perl-)	63	Although the module will work in the presence of other (Perl-) threads,
85	threads, it is currently not reentrant in any way, so use appropriate	64	it is currently not reentrant in any way, so use appropriate locking
86	locking yourself, always call C<poll_cb> from within the same thread, or	65	yourself, always call C<poll_cb> from within the same thread, or never
87	never call C<poll_cb> (or other C<aio_> functions) recursively.	66	call C<poll_cb> (or other C<aio_> functions) recursively.
88		67
89	=head2 EXAMPLE	68	=head2 EXAMPLE
90		69
91	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
92	F</etc/passwd> asynchronously:	71	F</etc/passwd> asynchronously:
93		72
94	use Fcntl;	73	use Fcntl;
95	use Event;	74	use EV;
96	use IO::AIO;	75	use IO::AIO;
97		76
98	# register the IO::AIO callback with Event	77	# register the IO::AIO callback with EV
99	Event->io (fd => IO::AIO::poll_fileno,	78	my $aio_w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb;
100	poll => 'r',
101	cb => \&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", O_RDONLY, 0, sub {
105	my $fh = shift	82	my $fh = shift
106	or die "error while opening: $!";	83	or die "error while opening: $!";
…		…
118		95
119	# file contents now in $contents	96	# file contents now in $contents
120	print $contents;	97	print $contents;
121		98
122	# exit event loop and program	99	# exit event loop and program
123	Event::unloop;	100	EV::unloop;
124	};	101	};
125	};	102	};
126		103
127	# possibly queue up other requests, or open GUI windows,	104	# possibly queue up other requests, or open GUI windows,
128	# check for sockets etc. etc.	105	# check for sockets etc. etc.
129		106
130	# process events as long as there are some:	107	# process events as long as there are some:
131	Event::loop;	108	EV::loop;
132		109
133	=head1 REQUEST ANATOMY AND LIFETIME	110	=head1 REQUEST ANATOMY AND LIFETIME
134		111
135	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
136	directly visible to Perl.	113	directly visible to Perl.
…		…
184		161
185	=cut	162	=cut
186		163
187	package IO::AIO;	164	package IO::AIO;
188		165
189	no warnings;	166	use Carp ();
190	use strict 'vars';	167
		168	use common::sense;
191		169
192	use base 'Exporter';	170	use base 'Exporter';
193		171
194	BEGIN {	172	BEGIN {
195	our $VERSION = '2.4';	173	our $VERSION = '3.5';
196		174
197	our @AIO_REQ = qw(aio_sendfile aio_read aio_write aio_open aio_close aio_stat	175	our @AIO_REQ = qw(aio_sendfile aio_read aio_write aio_open aio_close
198	aio_lstat aio_unlink aio_rmdir aio_readdir aio_scandir aio_symlink	176	aio_stat aio_lstat aio_unlink aio_rmdir aio_readdir aio_readdirx
199	aio_readlink aio_fsync aio_fdatasync aio_readahead aio_rename aio_link	177	aio_scandir aio_symlink aio_readlink aio_sync aio_fsync
		178	aio_fdatasync aio_sync_file_range aio_pathsync aio_readahead
		179	aio_rename aio_link aio_move aio_copy aio_group
200	aio_move aio_copy aio_group aio_nop aio_mknod aio_load aio_rmtree aio_mkdir	180	aio_nop aio_mknod aio_load aio_rmtree aio_mkdir aio_chown
		181	aio_chmod aio_utime aio_truncate
201	aio_chown aio_chmod aio_utime);	182	aio_msync aio_mtouch aio_statvfs);
		183
202	our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice aio_block));	184	our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice));
203	our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush	185	our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush
204	min_parallel max_parallel max_idle	186	min_parallel max_parallel max_idle
205	nreqs nready npending nthreads	187	nreqs nready npending nthreads
206	max_poll_time max_poll_reqs);	188	max_poll_time max_poll_reqs
		189	sendfile fadvise);
		190
		191	push @AIO_REQ, qw(aio_busy); # not exported
207		192
208	@IO::AIO::GRP::ISA = 'IO::AIO::REQ';	193	@IO::AIO::GRP::ISA = 'IO::AIO::REQ';
209		194
210	require XSLoader;	195	require XSLoader;
211	XSLoader::load ("IO::AIO", $VERSION);	196	XSLoader::load ("IO::AIO", $VERSION);
212	}	197	}
213		198
214	=head1 FUNCTIONS	199	=head1 FUNCTIONS
		200
		201	=head2 QUICK OVERVIEW
		202
		203	This section simply lists the prototypes of the most important functions
		204	for quick reference. See the following sections for function-by-function
		205	documentation.
		206
		207	aio_open $pathname, $flags, $mode, $callback->($fh)
		208	aio_close $fh, $callback->($status)
		209	aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
		210	aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
		211	aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval)
		212	aio_readahead $fh,$offset,$length, $callback->($retval)
		213	aio_stat $fh_or_path, $callback->($status)
		214	aio_lstat $fh, $callback->($status)
		215	aio_statvfs $fh_or_path, $callback->($statvfs)
		216	aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
		217	aio_chown $fh_or_path, $uid, $gid, $callback->($status)
		218	aio_truncate $fh_or_path, $offset, $callback->($status)
		219	aio_chmod $fh_or_path, $mode, $callback->($status)
		220	aio_unlink $pathname, $callback->($status)
		221	aio_mknod $path, $mode, $dev, $callback->($status)
		222	aio_link $srcpath, $dstpath, $callback->($status)
		223	aio_symlink $srcpath, $dstpath, $callback->($status)
		224	aio_readlink $path, $callback->($link)
		225	aio_rename $srcpath, $dstpath, $callback->($status)
		226	aio_mkdir $pathname, $mode, $callback->($status)
		227	aio_rmdir $pathname, $callback->($status)
		228	aio_readdir $pathname, $callback->($entries)
		229	aio_readdirx $pathname, $flags, $callback->($entries, $flags)
		230	IO::AIO::READDIR_DENTS IO::AIO::READDIR_DIRS_FIRST
		231	IO::AIO::READDIR_STAT_ORDER IO::AIO::READDIR_FOUND_UNKNOWN
		232	aio_load $path, $data, $callback->($status)
		233	aio_copy $srcpath, $dstpath, $callback->($status)
		234	aio_move $srcpath, $dstpath, $callback->($status)
		235	aio_scandir $path, $maxreq, $callback->($dirs, $nondirs)
		236	aio_rmtree $path, $callback->($status)
		237	aio_sync $callback->($status)
		238	aio_fsync $fh, $callback->($status)
		239	aio_fdatasync $fh, $callback->($status)
		240	aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status)
		241	aio_pathsync $path, $callback->($status)
		242	aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
		243	aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
		244	aio_group $callback->(...)
		245	aio_nop $callback->()
		246
		247	$prev_pri = aioreq_pri [$pri]
		248	aioreq_nice $pri_adjust
		249
		250	IO::AIO::poll_wait
		251	IO::AIO::poll_cb
		252	IO::AIO::poll
		253	IO::AIO::flush
		254	IO::AIO::max_poll_reqs $nreqs
		255	IO::AIO::max_poll_time $seconds
		256	IO::AIO::min_parallel $nthreads
		257	IO::AIO::max_parallel $nthreads
		258	IO::AIO::max_idle $nthreads
		259	IO::AIO::max_outstanding $maxreqs
		260	IO::AIO::nreqs
		261	IO::AIO::nready
		262	IO::AIO::npending
		263
		264	IO::AIO::sendfile $ofh, $ifh, $offset, $count
		265	IO::AIO::fadvise $fh, $offset, $len, $advice
		266	IO::AIO::mlockall $flags
		267	IO::AIO::munlockall
215		268
216	=head2 AIO REQUEST FUNCTIONS	269	=head2 AIO REQUEST FUNCTIONS
217		270
218	All the C<aio_*> calls are more or less thin wrappers around the syscall	271	All the C<aio_*> calls are more or less thin wrappers around the syscall
219	with the same name (sans C<aio_>). The arguments are similar or identical,	272	with the same name (sans C<aio_>). The arguments are similar or identical,
220	and they all accept an additional (and optional) C<$callback> argument	273	and they all accept an additional (and optional) C<$callback> argument
221	which must be a code reference. This code reference will get called with	274	which must be a code reference. This code reference will get called with
222	the syscall return code (e.g. most syscalls return C<-1> on error, unlike	275	the syscall return code (e.g. most syscalls return C<-1> on error, unlike
223	perl, which usually delivers "false") as it's sole argument when the given	276	perl, which usually delivers "false") as its sole argument after the given
224	syscall has been executed asynchronously.	277	syscall has been executed asynchronously.
225		278
226	All functions expecting a filehandle keep a copy of the filehandle	279	All functions expecting a filehandle keep a copy of the filehandle
227	internally until the request has finished.	280	internally until the request has finished.
228		281
…		…
242	your pathnames to the locale (or other) encoding in effect in the user	295	your pathnames to the locale (or other) encoding in effect in the user
243	environment, d) use Glib::filename_from_unicode on unicode filenames or e)	296	environment, d) use Glib::filename_from_unicode on unicode filenames or e)
244	use something else to ensure your scalar has the correct contents.	297	use something else to ensure your scalar has the correct contents.
245		298
246	This works, btw. independent of the internal UTF-8 bit, which IO::AIO	299	This works, btw. independent of the internal UTF-8 bit, which IO::AIO
247	handles correctly wether it is set or not.	300	handles correctly whether it is set or not.
248		301
249	=over 4	302	=over 4
250		303
251	=item $prev_pri = aioreq_pri [$pri]	304	=item $prev_pri = aioreq_pri [$pri]
252		305
…		…
312		365
313		366
314	=item aio_close $fh, $callback->($status)	367	=item aio_close $fh, $callback->($status)
315		368
316	Asynchronously close a file and call the callback with the result	369	Asynchronously close a file and call the callback with the result
317	code. I<WARNING:> although accepted, you should not pass in a perl	370	code.
318	filehandle here, as perl will likely close the file descriptor another
319	time when the filehandle is destroyed. Normally, you can safely call perls
320	C<close> or just let filehandles go out of scope.
321		371
322	This is supposed to be a bug in the API, so that might change. It's	372	Unfortunately, you can't do this to perl. Perl I<insists> very strongly on
323	therefore best to avoid this function.	373	closing the file descriptor associated with the filehandle itself.
324		374
		375	Therefore, C<aio_close> will not close the filehandle - instead it will
		376	use dup2 to overwrite the file descriptor with the write-end of a pipe
		377	(the pipe fd will be created on demand and will be cached).
		378
		379	Or in other words: the file descriptor will be closed, but it will not be
		380	free for reuse until the perl filehandle is closed.
		381
		382	=cut
325		383
326	=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)	384	=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
327		385
328	=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)	386	=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
329		387
330	Reads or writes C<length> bytes from the specified C<fh> and C<offset>	388	Reads or writes C<$length> bytes from or to the specified C<$fh> and
331	into the scalar given by C<data> and offset C<dataoffset> and calls the	389	C<$offset> into the scalar given by C<$data> and offset C<$dataoffset>
332	callback without the actual number of bytes read (or -1 on error, just	390	and calls the callback without the actual number of bytes read (or -1 on
333	like the syscall).	391	error, just like the syscall).
		392
		393	C<aio_read> will, like C<sysread>, shrink or grow the C<$data> scalar to
		394	offset plus the actual number of bytes read.
		395
		396	If C<$offset> is undefined, then the current file descriptor offset will
		397	be used (and updated), otherwise the file descriptor offset will not be
		398	changed by these calls.
		399
		400	If C<$length> is undefined in C<aio_write>, use the remaining length of
		401	C<$data>.
		402
		403	If C<$dataoffset> is less than zero, it will be counted from the end of
		404	C<$data>.
334		405
335	The C<$data> scalar I<MUST NOT> be modified in any way while the request	406	The C<$data> scalar I<MUST NOT> be modified in any way while the request
336	is outstanding. Modifying it can result in segfaults or WW3 (if the	407	is outstanding. Modifying it can result in segfaults or World War III (if
337	necessary/optional hardware is installed).	408	the necessary/optional hardware is installed).
338		409
339	Example: Read 15 bytes at offset 7 into scalar C<$buffer>, starting at	410	Example: Read 15 bytes at offset 7 into scalar C<$buffer>, starting at
340	offset C<0> within the scalar:	411	offset C<0> within the scalar:
341		412
342	aio_read $fh, 7, 15, $buffer, 0, sub {	413	aio_read $fh, 7, 15, $buffer, 0, sub {
…		…
353	than one C<aio_sendfile> per C<$out_fh>, as they will interfere with each	424	than one C<aio_sendfile> per C<$out_fh>, as they will interfere with each
354	other.	425	other.
355		426
356	This call tries to make use of a native C<sendfile> syscall to provide	427	This call tries to make use of a native C<sendfile> syscall to provide
357	zero-copy operation. For this to work, C<$out_fh> should refer to a	428	zero-copy operation. For this to work, C<$out_fh> should refer to a
358	socket, and C<$in_fh> should refer to mmap'able file.	429	socket, and C<$in_fh> should refer to an mmap'able file.
359		430
360	If the native sendfile call fails or is not implemented, it will be	431	If a native sendfile cannot be found or it fails with C<ENOSYS>,
		432	C<ENOTSUP>, C<EOPNOTSUPP>, C<EAFNOSUPPORT>, C<EPROTOTYPE> or C<ENOTSOCK>,
361	emulated, so you can call C<aio_sendfile> on any type of filehandle	433	it will be emulated, so you can call C<aio_sendfile> on any type of
362	regardless of the limitations of the operating system.	434	filehandle regardless of the limitations of the operating system.
363		435
364	Please note, however, that C<aio_sendfile> can read more bytes from	436	Please note, however, that C<aio_sendfile> can read more bytes from
365	C<$in_fh> than are written, and there is no way to find out how many	437	C<$in_fh> than are written, and there is no way to find out how many
366	bytes have been read from C<aio_sendfile> alone, as C<aio_sendfile> only	438	bytes have been read from C<aio_sendfile> alone, as C<aio_sendfile> only
367	provides the number of bytes written to C<$out_fh>. Only if the result	439	provides the number of bytes written to C<$out_fh>. Only if the result
…		…
405	$_[0] and die "stat failed: $!";	477	$_[0] and die "stat failed: $!";
406	print "size is ", -s _, "\n";	478	print "size is ", -s _, "\n";
407	};	479	};
408		480
409		481
		482	=item aio_statvfs $fh_or_path, $callback->($statvfs)
		483
		484	Works like the POSIX C<statvfs> or C<fstatvfs> syscalls, depending on
		485	whether a file handle or path was passed.
		486
		487	On success, the callback is passed a hash reference with the following
		488	members: C<bsize>, C<frsize>, C<blocks>, C<bfree>, C<bavail>, C<files>,
		489	C<ffree>, C<favail>, C<fsid>, C<flag> and C<namemax>. On failure, C<undef>
		490	is passed.
		491
		492	The following POSIX IO::AIO::ST_* constants are defined: C<ST_RDONLY> and
		493	C<ST_NOSUID>.
		494
		495	The following non-POSIX IO::AIO::ST_* flag masks are defined to
		496	their correct value when available, or to C<0> on systems that do
		497	not support them: C<ST_NODEV>, C<ST_NOEXEC>, C<ST_SYNCHRONOUS>,
		498	C<ST_MANDLOCK>, C<ST_WRITE>, C<ST_APPEND>, C<ST_IMMUTABLE>, C<ST_NOATIME>,
		499	C<ST_NODIRATIME> and C<ST_RELATIME>.
		500
		501	Example: stat C</wd> and dump out the data if successful.
		502
		503	aio_statvfs "/wd", sub {
		504	my $f = $_[0]
		505	or die "statvfs: $!";
		506
		507	use Data::Dumper;
		508	say Dumper $f;
		509	};
		510
		511	# result:
		512	{
		513	bsize => 1024,
		514	bfree => 4333064312,
		515	blocks => 10253828096,
		516	files => 2050765568,
		517	flag => 4096,
		518	favail => 2042092649,
		519	bavail => 4333064312,
		520	ffree => 2042092649,
		521	namemax => 255,
		522	frsize => 1024,
		523	fsid => 1810
		524	}
		525
		526
410	=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status)	527	=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
411		528
412	Works like perl's C<utime> function (including the special case of $atime	529	Works like perl's C<utime> function (including the special case of $atime
413	and $mtime being undef). Fractional times are supported if the underlying	530	and $mtime being undef). Fractional times are supported if the underlying
414	syscalls support them.	531	syscalls support them.
…		…
436	aio_chown "path", 0, -1;	553	aio_chown "path", 0, -1;
437	# same as above:	554	# same as above:
438	aio_chown "path", 0, undef;	555	aio_chown "path", 0, undef;
439		556
440		557
		558	=item aio_truncate $fh_or_path, $offset, $callback->($status)
		559
		560	Works like truncate(2) or ftruncate(2).
		561
		562
441	=item aio_chmod $fh_or_path, $mode, $callback->($status)	563	=item aio_chmod $fh_or_path, $mode, $callback->($status)
442		564
443	Works like perl's C<chmod> function.	565	Works like perl's C<chmod> function.
444		566
445		567
…		…
502		624
503	Unlike the POSIX call of the same name, C<aio_readdir> reads an entire	625	Unlike the POSIX call of the same name, C<aio_readdir> reads an entire
504	directory (i.e. opendir + readdir + closedir). The entries will not be	626	directory (i.e. opendir + readdir + closedir). The entries will not be
505	sorted, and will B<NOT> include the C<.> and C<..> entries.	627	sorted, and will B<NOT> include the C<.> and C<..> entries.
506		628
507	The callback a single argument which is either C<undef> or an array-ref	629	The callback is passed a single argument which is either C<undef> or an
508	with the filenames.	630	array-ref with the filenames.
		631
		632
		633	=item aio_readdirx $pathname, $flags, $callback->($entries, $flags)
		634
		635	Quite similar to C<aio_readdir>, but the C<$flags> argument allows to tune
		636	behaviour and output format. In case of an error, C<$entries> will be
		637	C<undef>.
		638
		639	The flags are a combination of the following constants, ORed together (the
		640	flags will also be passed to the callback, possibly modified):
		641
		642	=over 4
		643
		644	=item IO::AIO::READDIR_DENTS
		645
		646	When this flag is off, then the callback gets an arrayref with of names
		647	only (as with C<aio_readdir>), otherwise it gets an arrayref with
		648	C<[$name, $type, $inode]> arrayrefs, each describing a single directory
		649	entry in more detail.
		650
		651	C<$name> is the name of the entry.
		652
		653	C<$type> is one of the C<IO::AIO::DT_xxx> constants:
		654
		655	C<IO::AIO::DT_UNKNOWN>, C<IO::AIO::DT_FIFO>, C<IO::AIO::DT_CHR>, C<IO::AIO::DT_DIR>,
		656	C<IO::AIO::DT_BLK>, C<IO::AIO::DT_REG>, C<IO::AIO::DT_LNK>, C<IO::AIO::DT_SOCK>,
		657	C<IO::AIO::DT_WHT>.
		658
		659	C<IO::AIO::DT_UNKNOWN> means just that: readdir does not know. If you need to
		660	know, you have to run stat yourself. Also, for speed reasons, the C<$type>
		661	scalars are read-only: you can not modify them.
		662
		663	C<$inode> is the inode number (which might not be exact on systems with 64
		664	bit inode numbers and 32 bit perls). This field has unspecified content on
		665	systems that do not deliver the inode information.
		666
		667	=item IO::AIO::READDIR_DIRS_FIRST
		668
		669	When this flag is set, then the names will be returned in an order where
		670	likely directories come first. This is useful when you need to quickly
		671	find directories, or you want to find all directories while avoiding to
		672	stat() each entry.
		673
		674	If the system returns type information in readdir, then this is used
		675	to find directories directly. Otherwise, likely directories are files
		676	beginning with ".", or otherwise files with no dots, of which files with
		677	short names are tried first.
		678
		679	=item IO::AIO::READDIR_STAT_ORDER
		680
		681	When this flag is set, then the names will be returned in an order
		682	suitable for stat()'ing each one. That is, when you plan to stat()
		683	all files in the given directory, then the returned order will likely
		684	be fastest.
		685
		686	If both this flag and C<IO::AIO::READDIR_DIRS_FIRST> are specified, then
		687	the likely dirs come first, resulting in a less optimal stat order.
		688
		689	=item IO::AIO::READDIR_FOUND_UNKNOWN
		690
		691	This flag should not be set when calling C<aio_readdirx>. Instead, it
		692	is being set by C<aio_readdirx>, when any of the C<$type>'s found were
		693	C<IO::AIO::DT_UNKNOWN>. The absense of this flag therefore indicates that all
		694	C<$type>'s are known, which can be used to speed up some algorithms.
		695
		696	=back
509		697
510		698
511	=item aio_load $path, $data, $callback->($status)	699	=item aio_load $path, $data, $callback->($status)
512		700
513	This is a composite request that tries to fully load the given file into	701	This is a composite request that tries to fully load the given file into
514	memory. Status is the same as with aio_read.	702	memory. Status is the same as with aio_read.
515		703
516	=cut	704	=cut
517		705
518	sub aio_load($$;$) {	706	sub aio_load($$;$) {
519	aio_block {
520	my ($path, undef, $cb) = @_;	707	my ($path, undef, $cb) = @_;
521	my $data = \$_[1];	708	my $data = \$_[1];
522		709
523	my $pri = aioreq_pri;	710	my $pri = aioreq_pri;
524	my $grp = aio_group $cb;	711	my $grp = aio_group $cb;
		712
		713	aioreq_pri $pri;
		714	add $grp aio_open $path, O_RDONLY, 0, sub {
		715	my $fh = shift
		716	or return $grp->result (-1);
525		717
526	aioreq_pri $pri;	718	aioreq_pri $pri;
527	add $grp aio_open $path, O_RDONLY, 0, sub {
528	my $fh = shift
529	or return $grp->result (-1);
530
531	aioreq_pri $pri;
532	add $grp aio_read $fh, 0, (-s $fh), $$data, 0, sub {	719	add $grp aio_read $fh, 0, (-s $fh), $$data, 0, sub {
533	$grp->result ($_[0]);	720	$grp->result ($_[0]);
534	};
535	};	721	};
536
537	$grp
538	}	722	};
		723
		724	$grp
539	}	725	}
540		726
541	=item aio_copy $srcpath, $dstpath, $callback->($status)	727	=item aio_copy $srcpath, $dstpath, $callback->($status)
542		728
543	Try to copy the I<file> (directories not supported as either source or	729	Try to copy the I<file> (directories not supported as either source or
544	destination) from C<$srcpath> to C<$dstpath> and call the callback with	730	destination) from C<$srcpath> to C<$dstpath> and call the callback with
545	the C<0> (error) or C<-1> ok.	731	a status of C<0> (ok) or C<-1> (error, see C<$!>).
546		732
547	This is a composite request that it creates the destination file with	733	This is a composite request that creates the destination file with
548	mode 0200 and copies the contents of the source file into it using	734	mode 0200 and copies the contents of the source file into it using
549	C<aio_sendfile>, followed by restoring atime, mtime, access mode and	735	C<aio_sendfile>, followed by restoring atime, mtime, access mode and
550	uid/gid, in that order.	736	uid/gid, in that order.
551		737
552	If an error occurs, the partial destination file will be unlinked, if	738	If an error occurs, the partial destination file will be unlinked, if
…		…
554	errors are being ignored.	740	errors are being ignored.
555		741
556	=cut	742	=cut
557		743
558	sub aio_copy($$;$) {	744	sub aio_copy($$;$) {
559	aio_block {
560	my ($src, $dst, $cb) = @_;	745	my ($src, $dst, $cb) = @_;
561		746
562	my $pri = aioreq_pri;	747	my $pri = aioreq_pri;
563	my $grp = aio_group $cb;	748	my $grp = aio_group $cb;
564		749
565	aioreq_pri $pri;	750	aioreq_pri $pri;
566	add $grp aio_open $src, O_RDONLY, 0, sub {	751	add $grp aio_open $src, O_RDONLY, 0, sub {
567	if (my $src_fh = $_[0]) {	752	if (my $src_fh = $_[0]) {
568	my @stat = stat $src_fh;	753	my @stat = stat $src_fh; # hmm, might block over nfs?
569		754
570	aioreq_pri $pri;	755	aioreq_pri $pri;
571	add $grp aio_open $dst, O_CREAT \| O_WRONLY \| O_TRUNC, 0200, sub {	756	add $grp aio_open $dst, O_CREAT \| O_WRONLY \| O_TRUNC, 0200, sub {
572	if (my $dst_fh = $_[0]) {	757	if (my $dst_fh = $_[0]) {
573	aioreq_pri $pri;	758	aioreq_pri $pri;
574	add $grp aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub {	759	add $grp aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub {
575	if ($_[0] == $stat[7]) {	760	if ($_[0] == $stat[7]) {
576	$grp->result (0);	761	$grp->result (0);
577	close $src_fh;	762	close $src_fh;
578		763
579	# those should not normally block. should. should.
580	utime $stat[8], $stat[9], $dst;
581	chmod $stat[2] & 07777, $dst_fh;
582	chown $stat[4], $stat[5], $dst_fh;
583	close $dst_fh;
584	} else {	764	my $ch = sub {
585	$grp->result (-1);
586	close $src_fh;
587	close $dst_fh;
588
589	aioreq $pri;	765	aioreq_pri $pri;
		766	add $grp aio_chmod $dst_fh, $stat[2] & 07777, sub {
		767	aioreq_pri $pri;
		768	add $grp aio_chown $dst_fh, $stat[4], $stat[5], sub {
		769	aioreq_pri $pri;
590	add $grp aio_unlink $dst;	770	add $grp aio_close $dst_fh;
		771	}
		772	};
591	}	773	};
		774
		775	aioreq_pri $pri;
		776	add $grp aio_utime $dst_fh, $stat[8], $stat[9], sub {
		777	if ($_[0] < 0 && $! == ENOSYS) {
		778	aioreq_pri $pri;
		779	add $grp aio_utime $dst, $stat[8], $stat[9], $ch;
		780	} else {
		781	$ch->();
		782	}
		783	};
		784	} else {
		785	$grp->result (-1);
		786	close $src_fh;
		787	close $dst_fh;
		788
		789	aioreq $pri;
		790	add $grp aio_unlink $dst;
592	};	791	}
593	} else {
594	$grp->result (-1);
595	}	792	};
		793	} else {
		794	$grp->result (-1);
596	},	795	}
597
598	} else {
599	$grp->result (-1);
600	}	796	},
		797
		798	} else {
		799	$grp->result (-1);
601	};	800	}
602
603	$grp
604	}	801	};
		802
		803	$grp
605	}	804	}
606		805
607	=item aio_move $srcpath, $dstpath, $callback->($status)	806	=item aio_move $srcpath, $dstpath, $callback->($status)
608		807
609	Try to move the I<file> (directories not supported as either source or	808	Try to move the I<file> (directories not supported as either source or
610	destination) from C<$srcpath> to C<$dstpath> and call the callback with	809	destination) from C<$srcpath> to C<$dstpath> and call the callback with
611	the C<0> (error) or C<-1> ok.	810	a status of C<0> (ok) or C<-1> (error, see C<$!>).
612		811
613	This is a composite request that tries to rename(2) the file first. If	812	This is a composite request that tries to rename(2) the file first; if
614	rename files with C<EXDEV>, it copies the file with C<aio_copy> and, if	813	rename fails with C<EXDEV>, it copies the file with C<aio_copy> and, if
615	that is successful, unlinking the C<$srcpath>.	814	that is successful, unlinks the C<$srcpath>.
616		815
617	=cut	816	=cut
618		817
619	sub aio_move($$;$) {	818	sub aio_move($$;$) {
620	aio_block {
621	my ($src, $dst, $cb) = @_;	819	my ($src, $dst, $cb) = @_;
622		820
623	my $pri = aioreq_pri;	821	my $pri = aioreq_pri;
624	my $grp = aio_group $cb;	822	my $grp = aio_group $cb;
625		823
626	aioreq_pri $pri;	824	aioreq_pri $pri;
627	add $grp aio_rename $src, $dst, sub {	825	add $grp aio_rename $src, $dst, sub {
628	if ($_[0] && $! == EXDEV) {	826	if ($_[0] && $! == EXDEV) {
629	aioreq_pri $pri;	827	aioreq_pri $pri;
630	add $grp aio_copy $src, $dst, sub {	828	add $grp aio_copy $src, $dst, sub {
631	$grp->result ($_[0]);
632
633	if (!$_[0]) {
634	aioreq_pri $pri;
635	add $grp aio_unlink $src;
636	}
637	};
638	} else {
639	$grp->result ($_[0]);	829	$grp->result ($_[0]);
		830
		831	if (!$_[0]) {
		832	aioreq_pri $pri;
		833	add $grp aio_unlink $src;
		834	}
640	}	835	};
		836	} else {
		837	$grp->result ($_[0]);
641	};	838	}
642
643	$grp
644	}	839	};
		840
		841	$grp
645	}	842	}
646		843
647	=item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs)	844	=item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs)
648		845
649	Scans a directory (similar to C<aio_readdir>) but additionally tries to	846	Scans a directory (similar to C<aio_readdir>) but additionally tries to
…		…
669		866
670	Implementation notes.	867	Implementation notes.
671		868
672	The C<aio_readdir> cannot be avoided, but C<stat()>'ing every entry can.	869	The C<aio_readdir> cannot be avoided, but C<stat()>'ing every entry can.
673		870
		871	If readdir returns file type information, then this is used directly to
		872	find directories.
		873
674	After reading the directory, the modification time, size etc. of the	874	Otherwise, after reading the directory, the modification time, size etc.
675	directory before and after the readdir is checked, and if they match (and	875	of the directory before and after the readdir is checked, and if they
676	isn't the current time), the link count will be used to decide how many	876	match (and isn't the current time), the link count will be used to decide
677	entries are directories (if >= 2). Otherwise, no knowledge of the number	877	how many entries are directories (if >= 2). Otherwise, no knowledge of the
678	of subdirectories will be assumed.	878	number of subdirectories will be assumed.
679		879
680	Then entries will be sorted into likely directories (everything without	880	Then entries will be sorted into likely directories a non-initial dot
681	a non-initial dot currently) and likely non-directories (everything	881	currently) and likely non-directories (see C<aio_readdirx>). Then every
682	else). Then every entry plus an appended C</.> will be C<stat>'ed,	882	entry plus an appended C</.> will be C<stat>'ed, likely directories first,
683	likely directories first. If that succeeds, it assumes that the entry	883	in order of their inode numbers. If that succeeds, it assumes that the
684	is a directory or a symlink to directory (which will be checked	884	entry is a directory or a symlink to directory (which will be checked
685	seperately). This is often faster than stat'ing the entry itself because	885	seperately). This is often faster than stat'ing the entry itself because
686	filesystems might detect the type of the entry without reading the inode	886	filesystems might detect the type of the entry without reading the inode
687	data (e.g. ext2fs filetype feature).	887	data (e.g. ext2fs filetype feature), even on systems that cannot return
		888	the filetype information on readdir.
688		889
689	If the known number of directories (link count - 2) has been reached, the	890	If the known number of directories (link count - 2) has been reached, the
690	rest of the entries is assumed to be non-directories.	891	rest of the entries is assumed to be non-directories.
691		892
692	This only works with certainty on POSIX (= UNIX) filesystems, which	893	This only works with certainty on POSIX (= UNIX) filesystems, which
…		…
697	directory counting heuristic.	898	directory counting heuristic.
698		899
699	=cut	900	=cut
700		901
701	sub aio_scandir($$;$) {	902	sub aio_scandir($$;$) {
702	aio_block {
703	my ($path, $maxreq, $cb) = @_;	903	my ($path, $maxreq, $cb) = @_;
704		904
705	my $pri = aioreq_pri;	905	my $pri = aioreq_pri;
706		906
707	my $grp = aio_group $cb;	907	my $grp = aio_group $cb;
708		908
709	$maxreq = 4 if $maxreq <= 0;	909	$maxreq = 4 if $maxreq <= 0;
710		910
711	# stat once	911	# stat once
		912	aioreq_pri $pri;
		913	add $grp aio_stat $path, sub {
		914	return $grp->result () if $_[0];
		915	my $now = time;
		916	my $hash1 = join ":", (stat _)[0,1,3,7,9];
		917
		918	# read the directory entries
712	aioreq_pri $pri;	919	aioreq_pri $pri;
713	add $grp aio_stat $path, sub {	920	add $grp aio_readdirx $path, READDIR_DIRS_FIRST, sub {
		921	my $entries = shift
714	return $grp->result () if $_[0];	922	or return $grp->result ();
715	my $now = time;
716	my $hash1 = join ":", (stat _)[0,1,3,7,9];
717		923
718	# read the directory entries	924	# stat the dir another time
719	aioreq_pri $pri;	925	aioreq_pri $pri;
720	add $grp aio_readdir $path, sub {
721	my $entries = shift
722	or return $grp->result ();
723
724	# stat the dir another time
725	aioreq_pri $pri;
726	add $grp aio_stat $path, sub {	926	add $grp aio_stat $path, sub {
727	my $hash2 = join ":", (stat _)[0,1,3,7,9];	927	my $hash2 = join ":", (stat _)[0,1,3,7,9];
728		928
729	my $ndirs;	929	my $ndirs;
730		930
731	# take the slow route if anything looks fishy	931	# take the slow route if anything looks fishy
732	if ($hash1 ne $hash2 or (stat _)[9] == $now) {	932	if ($hash1 ne $hash2 or (stat _)[9] == $now) {
733	$ndirs = -1;	933	$ndirs = -1;
734	} else {	934	} else {
735	# if nlink == 2, we are finished	935	# if nlink == 2, we are finished
736	# on non-posix-fs's, we rely on nlink < 2	936	# for non-posix-fs's, we rely on nlink < 2
737	$ndirs = (stat _)[3] - 2	937	$ndirs = (stat _)[3] - 2
738	or return $grp->result ([], $entries);	938	or return $grp->result ([], $entries);
739	}	939	}
740		940
741	# sort into likely dirs and likely nondirs
742	# dirs == files without ".", short entries first
743	$entries = [map $_->[0],
744	sort { $b->[1] cmp $a->[1] }
745	map [$_, sprintf "%s%04d", (/.\./ ? "1" : "0"), length],
746	@$entries];
747
748	my (@dirs, @nondirs);	941	my (@dirs, @nondirs);
749		942
750	my $statgrp = add $grp aio_group sub {	943	my $statgrp = add $grp aio_group sub {
751	$grp->result (\@dirs, \@nondirs);	944	$grp->result (\@dirs, \@nondirs);
752	};	945	};
753		946
754	limit $statgrp $maxreq;	947	limit $statgrp $maxreq;
755	feed $statgrp sub {	948	feed $statgrp sub {
756	return unless @$entries;	949	return unless @$entries;
757	my $entry = pop @$entries;	950	my $entry = shift @$entries;
758		951
759	aioreq_pri $pri;	952	aioreq_pri $pri;
760	add $statgrp aio_stat "$path/$entry/.", sub {	953	add $statgrp aio_stat "$path/$entry/.", sub {
761	if ($_[0] < 0) {	954	if ($_[0] < 0) {
762	push @nondirs, $entry;	955	push @nondirs, $entry;
763	} else {	956	} else {
764	# need to check for real directory	957	# need to check for real directory
765	aioreq_pri $pri;	958	aioreq_pri $pri;
766	add $statgrp aio_lstat "$path/$entry", sub {	959	add $statgrp aio_lstat "$path/$entry", sub {
767	if (-d _) {	960	if (-d _) {
768	push @dirs, $entry;	961	push @dirs, $entry;
769		962
770	unless (--$ndirs) {	963	unless (--$ndirs) {
771	push @nondirs, @$entries;	964	push @nondirs, @$entries;
772	feed $statgrp;	965	feed $statgrp;
773	}
774	} else {
775	push @nondirs, $entry;
776	}	966	}
		967	} else {
		968	push @nondirs, $entry;
777	}	969	}
778	}	970	}
779	};	971	}
780	};	972	};
781	};	973	};
782	};	974	};
783	};	975	};
784
785	$grp
786	}	976	};
		977
		978	$grp
787	}	979	}
788		980
789	=item aio_rmtree $path, $callback->($status)	981	=item aio_rmtree $path, $callback->($status)
790		982
791	Delete a directory tree starting (and including) C<$path>, return the	983	Delete a directory tree starting (and including) C<$path>, return the
…		…
795		987
796	=cut	988	=cut
797		989
798	sub aio_rmtree;	990	sub aio_rmtree;
799	sub aio_rmtree($;$) {	991	sub aio_rmtree($;$) {
800	aio_block {
801	my ($path, $cb) = @_;	992	my ($path, $cb) = @_;
802		993
803	my $pri = aioreq_pri;	994	my $pri = aioreq_pri;
804	my $grp = aio_group $cb;	995	my $grp = aio_group $cb;
805		996
806	aioreq_pri $pri;	997	aioreq_pri $pri;
807	add $grp aio_scandir $path, 0, sub {	998	add $grp aio_scandir $path, 0, sub {
808	my ($dirs, $nondirs) = @_;	999	my ($dirs, $nondirs) = @_;
809		1000
810	my $dirgrp = aio_group sub {	1001	my $dirgrp = aio_group sub {
811	add $grp aio_rmdir $path, sub {	1002	add $grp aio_rmdir $path, sub {
812	$grp->result ($_[0]);	1003	$grp->result ($_[0]);
813	};
814	};	1004	};
815
816	(aioreq_pri $pri), add $dirgrp aio_rmtree "$path/$_" for @$dirs;
817	(aioreq_pri $pri), add $dirgrp aio_unlink "$path/$_" for @$nondirs;
818
819	add $grp $dirgrp;
820	};	1005	};
821		1006
822	$grp	1007	(aioreq_pri $pri), add $dirgrp aio_rmtree "$path/$_" for @$dirs;
		1008	(aioreq_pri $pri), add $dirgrp aio_unlink "$path/$_" for @$nondirs;
		1009
		1010	add $grp $dirgrp;
823	}	1011	};
		1012
		1013	$grp
824	}	1014	}
		1015
		1016	=item aio_sync $callback->($status)
		1017
		1018	Asynchronously call sync and call the callback when finished.
825		1019
826	=item aio_fsync $fh, $callback->($status)	1020	=item aio_fsync $fh, $callback->($status)
827		1021
828	Asynchronously call fsync on the given filehandle and call the callback	1022	Asynchronously call fsync on the given filehandle and call the callback
829	with the fsync result code.	1023	with the fsync result code.
…		…
833	Asynchronously call fdatasync on the given filehandle and call the	1027	Asynchronously call fdatasync on the given filehandle and call the
834	callback with the fdatasync result code.	1028	callback with the fdatasync result code.
835		1029
836	If this call isn't available because your OS lacks it or it couldn't be	1030	If this call isn't available because your OS lacks it or it couldn't be
837	detected, it will be emulated by calling C<fsync> instead.	1031	detected, it will be emulated by calling C<fsync> instead.
		1032
		1033	=item aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status)
		1034
		1035	Sync the data portion of the file specified by C<$offset> and C<$length>
		1036	to disk (but NOT the metadata), by calling the Linux-specific
		1037	sync_file_range call. If sync_file_range is not available or it returns
		1038	ENOSYS, then fdatasync or fsync is being substituted.
		1039
		1040	C<$flags> can be a combination of C<IO::AIO::SYNC_FILE_RANGE_WAIT_BEFORE>,
		1041	C<IO::AIO::SYNC_FILE_RANGE_WRITE> and
		1042	C<IO::AIO::SYNC_FILE_RANGE_WAIT_AFTER>: refer to the sync_file_range
		1043	manpage for details.
		1044
		1045	=item aio_pathsync $path, $callback->($status)
		1046
		1047	This request tries to open, fsync and close the given path. This is a
		1048	composite request intended to sync directories after directory operations
		1049	(E.g. rename). This might not work on all operating systems or have any
		1050	specific effect, but usually it makes sure that directory changes get
		1051	written to disc. It works for anything that can be opened for read-only,
		1052	not just directories.
		1053
		1054	Future versions of this function might fall back to other methods when
		1055	C<fsync> on the directory fails (such as calling C<sync>).
		1056
		1057	Passes C<0> when everything went ok, and C<-1> on error.
		1058
		1059	=cut
		1060
		1061	sub aio_pathsync($;$) {
		1062	my ($path, $cb) = @_;
		1063
		1064	my $pri = aioreq_pri;
		1065	my $grp = aio_group $cb;
		1066
		1067	aioreq_pri $pri;
		1068	add $grp aio_open $path, O_RDONLY, 0, sub {
		1069	my ($fh) = @_;
		1070	if ($fh) {
		1071	aioreq_pri $pri;
		1072	add $grp aio_fsync $fh, sub {
		1073	$grp->result ($_[0]);
		1074
		1075	aioreq_pri $pri;
		1076	add $grp aio_close $fh;
		1077	};
		1078	} else {
		1079	$grp->result (-1);
		1080	}
		1081	};
		1082
		1083	$grp
		1084	}
		1085
		1086	=item aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
		1087
		1088	This is a rather advanced IO::AIO call, which only works on mmap(2)ed
		1089	scalars (see the C<IO::AIO::mmap> function, although it also works on data
		1090	scalars managed by the L<Sys::Mmap> or L<Mmap> modules, note that the
		1091	scalar must only be modified in-place while an aio operation is pending on
		1092	it).
		1093
		1094	It calls the C<msync> function of your OS, if available, with the memory
		1095	area starting at C<$offset> in the string and ending C<$length> bytes
		1096	later. If C<$length> is negative, counts from the end, and if C<$length>
		1097	is C<undef>, then it goes till the end of the string. The flags can be
		1098	a combination of C<IO::AIO::MS_ASYNC>, C<IO::AIO::MS_INVALIDATE> and
		1099	C<IO::AIO::MS_SYNC>.
		1100
		1101	=item aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
		1102
		1103	This is a rather advanced IO::AIO call, which works best on mmap(2)ed
		1104	scalars.
		1105
		1106	It touches (reads or writes) all memory pages in the specified
		1107	range inside the scalar. All caveats and parameters are the same
		1108	as for C<aio_msync>, above, except for flags, which must be either
		1109	C<0> (which reads all pages and ensures they are instantiated) or
		1110	C<IO::AIO::MT_MODIFY>, which modifies the memory page s(by reading and
		1111	writing an octet from it, which dirties the page).
838		1112
839	=item aio_group $callback->(...)	1113	=item aio_group $callback->(...)
840		1114
841	This is a very special aio request: Instead of doing something, it is a	1115	This is a very special aio request: Instead of doing something, it is a
842	container for other aio requests, which is useful if you want to bundle	1116	container for other aio requests, which is useful if you want to bundle
…		…
892	=item cancel $req	1166	=item cancel $req
893		1167
894	Cancels the request, if possible. Has the effect of skipping execution	1168	Cancels the request, if possible. Has the effect of skipping execution
895	when entering the B<execute> state and skipping calling the callback when	1169	when entering the B<execute> state and skipping calling the callback when
896	entering the the B<result> state, but will leave the request otherwise	1170	entering the the B<result> state, but will leave the request otherwise
897	untouched. That means that requests that currently execute will not be	1171	untouched (with the exception of readdir). That means that requests that
898	stopped and resources held by the request will not be freed prematurely.	1172	currently execute will not be stopped and resources held by the request
		1173	will not be freed prematurely.
899		1174
900	=item cb $req $callback->(...)	1175	=item cb $req $callback->(...)
901		1176
902	Replace (or simply set) the callback registered to the request.	1177	Replace (or simply set) the callback registered to the request.
903		1178
…		…
954	Their lifetime, simplified, looks like this: when they are empty, they	1229	Their lifetime, simplified, looks like this: when they are empty, they
955	will finish very quickly. If they contain only requests that are in the	1230	will finish very quickly. If they contain only requests that are in the
956	C<done> state, they will also finish. Otherwise they will continue to	1231	C<done> state, they will also finish. Otherwise they will continue to
957	exist.	1232	exist.
958		1233
959	That means after creating a group you have some time to add requests. And	1234	That means after creating a group you have some time to add requests
960	in the callbacks of those requests, you can add further requests to the	1235	(precisely before the callback has been invoked, which is only done within
961	group. And only when all those requests have finished will the the group	1236	the C<poll_cb>). And in the callbacks of those requests, you can add
962	itself finish.	1237	further requests to the group. And only when all those requests have
		1238	finished will the the group itself finish.
963		1239
964	=over 4	1240	=over 4
965		1241
966	=item add $grp ...	1242	=item add $grp ...
967		1243
…		…
976	=item $grp->cancel_subs	1252	=item $grp->cancel_subs
977		1253
978	Cancel all subrequests and clears any feeder, but not the group request	1254	Cancel all subrequests and clears any feeder, but not the group request
979	itself. Useful when you queued a lot of events but got a result early.	1255	itself. Useful when you queued a lot of events but got a result early.
980		1256
		1257	The group request will finish normally (you cannot add requests to the
		1258	group).
		1259
981	=item $grp->result (...)	1260	=item $grp->result (...)
982		1261
983	Set the result value(s) that will be passed to the group callback when all	1262	Set the result value(s) that will be passed to the group callback when all
984	subrequests have finished and set thre groups errno to the current value	1263	subrequests have finished and set the groups errno to the current value
985	of errno (just like calling C<errno> without an error number). By default,	1264	of errno (just like calling C<errno> without an error number). By default,
986	no argument will be passed and errno is zero.	1265	no argument will be passed and errno is zero.
987		1266
988	=item $grp->errno ([$errno])	1267	=item $grp->errno ([$errno])
989		1268
…		…
1000	=item feed $grp $callback->($grp)	1279	=item feed $grp $callback->($grp)
1001		1280
1002	Sets a feeder/generator on this group: every group can have an attached	1281	Sets a feeder/generator on this group: every group can have an attached
1003	generator that generates requests if idle. The idea behind this is that,	1282	generator that generates requests if idle. The idea behind this is that,
1004	although you could just queue as many requests as you want in a group,	1283	although you could just queue as many requests as you want in a group,
1005	this might starve other requests for a potentially long time. For	1284	this might starve other requests for a potentially long time. For example,
1006	example, C<aio_scandir> might generate hundreds of thousands C<aio_stat>	1285	C<aio_scandir> might generate hundreds of thousands C<aio_stat> requests,
1007	requests, delaying any later requests for a long time.	1286	delaying any later requests for a long time.
1008		1287
1009	To avoid this, and allow incremental generation of requests, you can	1288	To avoid this, and allow incremental generation of requests, you can
1010	instead a group and set a feeder on it that generates those requests. The	1289	instead a group and set a feeder on it that generates those requests. The
1011	feed callback will be called whenever there are few enough (see C<limit>,	1290	feed callback will be called whenever there are few enough (see C<limit>,
1012	below) requests active in the group itself and is expected to queue more	1291	below) requests active in the group itself and is expected to queue more
…		…
1016	not impose any limits).	1295	not impose any limits).
1017		1296
1018	If the feed does not queue more requests when called, it will be	1297	If the feed does not queue more requests when called, it will be
1019	automatically removed from the group.	1298	automatically removed from the group.
1020		1299
1021	If the feed limit is C<0>, it will be set to C<2> automatically.	1300	If the feed limit is C<0> when this method is called, it will be set to
		1301	C<2> automatically.
1022		1302
1023	Example:	1303	Example:
1024		1304
1025	# stat all files in @files, but only ever use four aio requests concurrently:	1305	# stat all files in @files, but only ever use four aio requests concurrently:
1026		1306
…		…
1038	Sets the feeder limit for the group: The feeder will be called whenever	1318	Sets the feeder limit for the group: The feeder will be called whenever
1039	the group contains less than this many requests.	1319	the group contains less than this many requests.
1040		1320
1041	Setting the limit to C<0> will pause the feeding process.	1321	Setting the limit to C<0> will pause the feeding process.
1042		1322
		1323	The default value for the limit is C<0>, but note that setting a feeder
		1324	automatically bumps it up to C<2>.
		1325
1043	=back	1326	=back
1044		1327
1045	=head2 SUPPORT FUNCTIONS	1328	=head2 SUPPORT FUNCTIONS
1046		1329
1047	=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION	1330	=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION
…		…
1049	=over 4	1332	=over 4
1050		1333
1051	=item $fileno = IO::AIO::poll_fileno	1334	=item $fileno = IO::AIO::poll_fileno
1052		1335
1053	Return the I<request result pipe file descriptor>. This filehandle must be	1336	Return the I<request result pipe file descriptor>. This filehandle must be
1054	polled for reading by some mechanism outside this module (e.g. Event or	1337	polled for reading by some mechanism outside this module (e.g. EV, Glib,
1055	select, see below or the SYNOPSIS). If the pipe becomes readable you have	1338	select and so on, see below or the SYNOPSIS). If the pipe becomes readable
1056	to call C<poll_cb> to check the results.	1339	you have to call C<poll_cb> to check the results.
1057		1340
1058	See C<poll_cb> for an example.	1341	See C<poll_cb> for an example.
1059		1342
1060	=item IO::AIO::poll_cb	1343	=item IO::AIO::poll_cb
1061		1344
1062	Process some outstanding events on the result pipe. You have to call this	1345	Process some outstanding events on the result pipe. You have to call this
1063	regularly. Returns the number of events processed. Returns immediately	1346	regularly. Returns C<0> if all events could be processed, or C<-1> if it
		1347	returned earlier for whatever reason. Returns immediately when no events
1064	when no events are outstanding. The amount of events processed depends on	1348	are outstanding. The amount of events processed depends on the settings of
1065	the settings of C<IO::AIO::max_poll_req> and C<IO::AIO::max_poll_time>.	1349	C<IO::AIO::max_poll_req> and C<IO::AIO::max_poll_time>.
1066		1350
1067	If not all requests were processed for whatever reason, the filehandle	1351	If not all requests were processed for whatever reason, the filehandle
1068	will still be ready when C<poll_cb> returns.	1352	will still be ready when C<poll_cb> returns, so normally you don't have to
		1353	do anything special to have it called later.
1069		1354
1070	Example: Install an Event watcher that automatically calls	1355	Example: Install an Event watcher that automatically calls
1071	IO::AIO::poll_cb with high priority:	1356	IO::AIO::poll_cb with high priority (more examples can be found in the
		1357	SYNOPSIS section, at the top of this document):
1072		1358
1073	Event->io (fd => IO::AIO::poll_fileno,	1359	Event->io (fd => IO::AIO::poll_fileno,
1074	poll => 'r', async => 1,	1360	poll => 'r', async => 1,
1075	cb => \&IO::AIO::poll_cb);	1361	cb => \&IO::AIO::poll_cb);
		1362
		1363	=item IO::AIO::poll_wait
		1364
		1365	If there are any outstanding requests and none of them in the result
		1366	phase, wait till the result filehandle becomes ready for reading (simply
		1367	does a C<select> on the filehandle. This is useful if you want to
		1368	synchronously wait for some requests to finish).
		1369
		1370	See C<nreqs> for an example.
		1371
		1372	=item IO::AIO::poll
		1373
		1374	Waits until some requests have been handled.
		1375
		1376	Returns the number of requests processed, but is otherwise strictly
		1377	equivalent to:
		1378
		1379	IO::AIO::poll_wait, IO::AIO::poll_cb
		1380
		1381	=item IO::AIO::flush
		1382
		1383	Wait till all outstanding AIO requests have been handled.
		1384
		1385	Strictly equivalent to:
		1386
		1387	IO::AIO::poll_wait, IO::AIO::poll_cb
		1388	while IO::AIO::nreqs;
1076		1389
1077	=item IO::AIO::max_poll_reqs $nreqs	1390	=item IO::AIO::max_poll_reqs $nreqs
1078		1391
1079	=item IO::AIO::max_poll_time $seconds	1392	=item IO::AIO::max_poll_time $seconds
1080		1393
…		…
1105	# use a low priority so other tasks have priority	1418	# use a low priority so other tasks have priority
1106	Event->io (fd => IO::AIO::poll_fileno,	1419	Event->io (fd => IO::AIO::poll_fileno,
1107	poll => 'r', nice => 1,	1420	poll => 'r', nice => 1,
1108	cb => &IO::AIO::poll_cb);	1421	cb => &IO::AIO::poll_cb);
1109		1422
1110	=item IO::AIO::poll_wait
1111
1112	If there are any outstanding requests and none of them in the result
1113	phase, wait till the result filehandle becomes ready for reading (simply
1114	does a C<select> on the filehandle. This is useful if you want to
1115	synchronously wait for some requests to finish).
1116
1117	See C<nreqs> for an example.
1118
1119	=item IO::AIO::poll
1120
1121	Waits until some requests have been handled.
1122
1123	Returns the number of requests processed, but is otherwise strictly
1124	equivalent to:
1125
1126	IO::AIO::poll_wait, IO::AIO::poll_cb
1127
1128	=item IO::AIO::flush
1129
1130	Wait till all outstanding AIO requests have been handled.
1131
1132	Strictly equivalent to:
1133
1134	IO::AIO::poll_wait, IO::AIO::poll_cb
1135	while IO::AIO::nreqs;
1136
1137	=back	1423	=back
1138		1424
1139	=head3 CONTROLLING THE NUMBER OF THREADS	1425	=head3 CONTROLLING THE NUMBER OF THREADS
1140		1426
1141	=over	1427	=over
…		…
1187		1473
1188	The default is probably ok in most situations, especially if thread	1474	The default is probably ok in most situations, especially if thread
1189	creation is fast. If thread creation is very slow on your system you might	1475	creation is fast. If thread creation is very slow on your system you might
1190	want to use larger values.	1476	want to use larger values.
1191		1477
1192	=item $oldmaxreqs = IO::AIO::max_outstanding $maxreqs	1478	=item IO::AIO::max_outstanding $maxreqs
1193		1479
1194	This is a very bad function to use in interactive programs because it	1480	This is a very bad function to use in interactive programs because it
1195	blocks, and a bad way to reduce concurrency because it is inexact: Better	1481	blocks, and a bad way to reduce concurrency because it is inexact: Better
1196	use an C<aio_group> together with a feed callback.	1482	use an C<aio_group> together with a feed callback.
1197		1483
1198	Sets the maximum number of outstanding requests to C<$nreqs>. If you	1484	Sets the maximum number of outstanding requests to C<$nreqs>. If you
1199	to queue up more than this number of requests, the next call to the	1485	do queue up more than this number of requests, the next call to the
1200	C<poll_cb> (and C<poll_some> and other functions calling C<poll_cb>)	1486	C<poll_cb> (and C<poll_some> and other functions calling C<poll_cb>)
1201	function will block until the limit is no longer exceeded.	1487	function will block until the limit is no longer exceeded.
1202		1488
1203	The default value is very large, so there is no practical limit on the	1489	The default value is very large, so there is no practical limit on the
1204	number of outstanding requests.	1490	number of outstanding requests.
1205		1491
1206	You can still queue as many requests as you want. Therefore,	1492	You can still queue as many requests as you want. Therefore,
1207	C<max_oustsanding> is mainly useful in simple scripts (with low values) or	1493	C<max_outstanding> is mainly useful in simple scripts (with low values) or
1208	as a stop gap to shield against fatal memory overflow (with large values).	1494	as a stop gap to shield against fatal memory overflow (with large values).
1209		1495
1210	=back	1496	=back
1211		1497
1212	=head3 STATISTICAL INFORMATION	1498	=head3 STATISTICAL INFORMATION
…		…
1233	Returns the number of requests currently in the pending state (executed,	1519	Returns the number of requests currently in the pending state (executed,
1234	but not yet processed by poll_cb).	1520	but not yet processed by poll_cb).
1235		1521
1236	=back	1522	=back
1237		1523
		1524	=head3 MISCELLANEOUS FUNCTIONS
		1525
		1526	IO::AIO implements some functions that might be useful, but are not
		1527	asynchronous.
		1528
		1529	=over 4
		1530
		1531	=item IO::AIO::sendfile $ofh, $ifh, $offset, $count
		1532
		1533	Calls the C<eio_sendfile_sync> function, which is like C<aio_sendfile>,
		1534	but is blocking (this makes most sense if you know the input data is
		1535	likely cached already and the output filehandle is set to non-blocking
		1536	operations).
		1537
		1538	Returns the number of bytes copied, or C<-1> on error.
		1539
		1540	=item IO::AIO::fadvise $fh, $offset, $len, $advice
		1541
		1542	Simply calls the C<posix_fadvise> function (see it's
		1543	manpage for details). The following advice constants are
		1544	avaiable: C<IO::AIO::FADV_NORMAL>, C<IO::AIO::FADV_SEQUENTIAL>,
		1545	C<IO::AIO::FADV_RANDOM>, C<IO::AIO::FADV_NOREUSE>,
		1546	C<IO::AIO::FADV_WILLNEED>, C<IO::AIO::FADV_DONTNEED>.
		1547
		1548	On systems that do not implement C<posix_fadvise>, this function returns
		1549	ENOSYS, otherwise the return value of C<posix_fadvise>.
		1550
		1551	=item IO::AIO::mmap $scalar, $length, $prot, $flags, $fh[, $offset]
		1552
		1553	Memory-maps a file (or anonymous memory range) and attaches it to the
		1554	given C<$scalar>, which will act like a string scalar.
		1555
		1556	The only operations allowed on the scalar are C<substr>/C<vec> that don't
		1557	change the string length, and most read-only operations such as copying it
		1558	or searching it with regexes and so on.
		1559
		1560	Anything else is unsafe and will, at best, result in memory leaks.
		1561
		1562	The memory map associated with the C<$scalar> is automatically removed
		1563	when the C<$scalar> is destroyed, or when the C<IO::AIO::mmap> or
		1564	C<IO::AIO::munmap> functions are called.
		1565
		1566	This calls the C<mmap>(2) function internally. See your system's manual
		1567	page for details on the C<$length>, C<$prot> and C<$flags> parameters.
		1568
		1569	The C<$length> must be larger than zero and smaller than the actual
		1570	filesize.
		1571
		1572	C<$prot> is a combination of C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_EXEC>,
		1573	C<IO::AIO::PROT_READ> and/or C<IO::AIO::PROT_WRITE>,
		1574
		1575	C<$flags> can be a combination of C<IO::AIO::MAP_SHARED> or
		1576	C<IO::AIO::MAP_PRIVATE>, or a number of system-specific flags (when
		1577	not available, the are defined as 0): C<IO::AIO::MAP_ANONYMOUS>
		1578	(which is set to C<MAP_ANON> if your system only provides this
		1579	constant), C<IO::AIO::MAP_HUGETLB>, C<IO::AIO::MAP_LOCKED>,
		1580	C<IO::AIO::MAP_NORESERVE>, C<IO::AIO::MAP_POPULATE> or
		1581	C<IO::AIO::MAP_NONBLOCK>
		1582
		1583	If C<$fh> is C<undef>, then a file descriptor of C<-1> is passed.
		1584
		1585	=item IO::AIO::munmap $scalar
		1586
		1587	Removes a previous mmap and undefines the C<$scalar>.
		1588
		1589	=item IO::AIO::mlockall $flags
		1590
		1591	Calls the C<mlockall> function with the given C<$flags> (a combination of
		1592	C<IO::AIO::MCL_CURRENT> and C<IO::AIO::MCL__FUTURE>).
		1593
		1594	On systems that do not implement C<mlockall>, this function returns
		1595	ENOSYS, otherwise the return value of C<mlockall>.
		1596
		1597	=item IO::AIO::munlockall
		1598
		1599	Calls the C<munlockall> function.
		1600
		1601	On systems that do not implement C<munlockall>, this function returns
		1602	ENOSYS, otherwise the return value of C<munlockall>.
		1603
		1604	=back
		1605
1238	=cut	1606	=cut
1239		1607
1240	# support function to convert a fd into a perl filehandle
1241	sub _fd2fh {
1242	return undef if $_[0] < 0;
1243
1244	# try to generate nice filehandles
1245	my $sym = "IO::AIO::fd#$_[0]";
1246	local *$sym;
1247
1248	open *$sym, "+<&=$_[0]" # usually works under any unix
1249	or open *$sym, "<&=$_[0]" # cygwin needs this
1250	or open *$sym, ">&=$_[0]" # or this
1251	or return undef;
1252
1253	*$sym
1254	}
1255
1256	min_parallel 8;	1608	min_parallel 8;
1257		1609
1258	END { flush }	1610	END { flush }
1259		1611
1260	1;	1612	1;
		1613
		1614	=head1 EVENT LOOP INTEGRATION
		1615
		1616	It is recommended to use L<AnyEvent::AIO> to integrate IO::AIO
		1617	automatically into many event loops:
		1618
		1619	# AnyEvent integration (EV, Event, Glib, Tk, POE, urxvt, pureperl...)
		1620	use AnyEvent::AIO;
		1621
		1622	You can also integrate IO::AIO manually into many event loops, here are
		1623	some examples of how to do this:
		1624
		1625	# EV integration
		1626	my $aio_w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb;
		1627
		1628	# Event integration
		1629	Event->io (fd => IO::AIO::poll_fileno,
		1630	poll => 'r',
		1631	cb => \&IO::AIO::poll_cb);
		1632
		1633	# Glib/Gtk2 integration
		1634	add_watch Glib::IO IO::AIO::poll_fileno,
		1635	in => sub { IO::AIO::poll_cb; 1 };
		1636
		1637	# Tk integration
		1638	Tk::Event::IO->fileevent (IO::AIO::poll_fileno, "",
		1639	readable => \&IO::AIO::poll_cb);
		1640
		1641	# Danga::Socket integration
		1642	Danga::Socket->AddOtherFds (IO::AIO::poll_fileno =>
		1643	\&IO::AIO::poll_cb);
1261		1644
1262	=head2 FORK BEHAVIOUR	1645	=head2 FORK BEHAVIOUR
1263		1646
1264	This module should do "the right thing" when the process using it forks:	1647	This module should do "the right thing" when the process using it forks:
1265		1648
…		…
1283	bytes of memory. In addition, stat requests need a stat buffer (possibly	1666	bytes of memory. In addition, stat requests need a stat buffer (possibly
1284	a few hundred bytes), readdir requires a result buffer and so on. Perl	1667	a few hundred bytes), readdir requires a result buffer and so on. Perl
1285	scalars and other data passed into aio requests will also be locked and	1668	scalars and other data passed into aio requests will also be locked and
1286	will consume memory till the request has entered the done state.	1669	will consume memory till the request has entered the done state.
1287		1670
1288	This is now awfully much, so queuing lots of requests is not usually a	1671	This is not awfully much, so queuing lots of requests is not usually a
1289	problem.	1672	problem.
1290		1673
1291	Per-thread usage:	1674	Per-thread usage:
1292		1675
1293	In the execution phase, some aio requests require more memory for	1676	In the execution phase, some aio requests require more memory for
…		…
1298		1681
1299	Known bugs will be fixed in the next release.	1682	Known bugs will be fixed in the next release.
1300		1683
1301	=head1 SEE ALSO	1684	=head1 SEE ALSO
1302		1685
1303	L<Coro::AIO>.	1686	L<AnyEvent::AIO> for easy integration into event loops, L<Coro::AIO> for a
		1687	more natural syntax.
1304		1688
1305	=head1 AUTHOR	1689	=head1 AUTHOR
1306		1690
1307	Marc Lehmann <schmorp@schmorp.de>	1691	Marc Lehmann <schmorp@schmorp.de>
1308	http://home.schmorp.de/	1692	http://home.schmorp.de/

Diff Legend

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

Comparing IO-AIO/AIO.pm (file contents): Revision 1.107 by root, Fri Jun 1 05:52:59 2007 UTC vs. Revision 1.176 by root, Sun Jan 10 23:05:11 2010 UTC

Diff Legend

Comparing IO-AIO/AIO.pm (file contents):
Revision 1.107 by root, Fri Jun 1 05:52:59 2007 UTC vs.
Revision 1.176 by root, Sun Jan 10 23:05:11 2010 UTC