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

Comparing IO-AIO/AIO.pm (file contents):
Revision 1.105 by root, Sun Mar 25 00:20:27 2007 UTC vs.
Revision 1.170 by root, Sat Jan 2 14:11:32 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 (EV, Event, Glib, Tk, POE, urxvt, pureperl...)
		32	use AnyEvent::AIO;
		33
31	# AnyEvent integration	34	# EV integration
32	open my $fh, "<&=" . IO::AIO::poll_fileno or die "$!";	35	my $aio_w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb;
33	my $w = AnyEvent->io (fh => $fh, poll => 'r', cb => sub { IO::AIO::poll_cb });
34		36
35	# Event integration	37	# Event integration
36	Event->io (fd => IO::AIO::poll_fileno,	38	Event->io (fd => IO::AIO::poll_fileno,
37	poll => 'r',	39	poll => 'r',
38	cb => \&IO::AIO::poll_cb);	40	cb => \&IO::AIO::poll_cb);
…		…
50	\&IO::AIO::poll_cb);	52	\&IO::AIO::poll_cb);
51		53
52	=head1 DESCRIPTION	54	=head1 DESCRIPTION
53		55
54	This module implements asynchronous I/O using whatever means your	56	This module implements asynchronous I/O using whatever means your
55	operating system supports.	57	operating system supports. It is implemented as an interface to C<libeio>
		58	(L<http://software.schmorp.de/pkg/libeio.html>).
56		59
57	Asynchronous means that operations that can normally block your program	60	Asynchronous means that operations that can normally block your program
58	(e.g. reading from disk) will be done asynchronously: the operation	61	(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	62	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	63	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	65	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	66	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	67	on a RAID volume or over NFS when you do a number of stat operations
65	concurrently.	68	concurrently.
66		69
67	While most of this works on all types of file descriptors (for example	70	While most of this works on all types of file descriptors (for
68	sockets), using these functions on file descriptors that support	71	example sockets), using these functions on file descriptors that
69	nonblocking operation (again, sockets, pipes etc.) is very inefficient or	72	support nonblocking operation (again, sockets, pipes etc.) is
70	might not work (aio_read fails on sockets/pipes/fifos). Use an event loop	73	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	74	module): IO::AIO will naturally fit into such an event loop itself.
72	into such an event loop itself.
73		75
74	In this version, a number of threads are started that execute your	76	In this version, a number of threads are started that execute your
75	requests and signal their completion. You don't need thread support	77	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	78	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	79	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	81	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	82	files currently, for example), and they would only support aio_read and
81	aio_write, so the remaining functionality would have to be implemented	83	aio_write, so the remaining functionality would have to be implemented
82	using threads anyway.	84	using threads anyway.
83		85
84	Although the module will work with in the presence of other (Perl-)	86	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	87	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	88	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.	89	call C<poll_cb> (or other C<aio_> functions) recursively.
88		90
89	=head2 EXAMPLE	91	=head2 EXAMPLE
90		92
91	This is a simple example that uses the Event module and loads	93	This is a simple example that uses the EV module and loads
92	F</etc/passwd> asynchronously:	94	F</etc/passwd> asynchronously:
93		95
94	use Fcntl;	96	use Fcntl;
95	use Event;	97	use EV;
96	use IO::AIO;	98	use IO::AIO;
97		99
98	# register the IO::AIO callback with Event	100	# register the IO::AIO callback with EV
99	Event->io (fd => IO::AIO::poll_fileno,	101	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		102
103	# queue the request to open /etc/passwd	103	# queue the request to open /etc/passwd
104	aio_open "/etc/passwd", O_RDONLY, 0, sub {	104	aio_open "/etc/passwd", O_RDONLY, 0, sub {
105	my $fh = shift	105	my $fh = shift
106	or die "error while opening: $!";	106	or die "error while opening: $!";
…		…
118		118
119	# file contents now in $contents	119	# file contents now in $contents
120	print $contents;	120	print $contents;
121		121
122	# exit event loop and program	122	# exit event loop and program
123	Event::unloop;	123	EV::unloop;
124	};	124	};
125	};	125	};
126		126
127	# possibly queue up other requests, or open GUI windows,	127	# possibly queue up other requests, or open GUI windows,
128	# check for sockets etc. etc.	128	# check for sockets etc. etc.
129		129
130	# process events as long as there are some:	130	# process events as long as there are some:
131	Event::loop;	131	EV::loop;
132		132
133	=head1 REQUEST ANATOMY AND LIFETIME	133	=head1 REQUEST ANATOMY AND LIFETIME
134		134
135	Every C<aio_*> function creates a request. which is a C data structure not	135	Every C<aio_*> function creates a request. which is a C data structure not
136	directly visible to Perl.	136	directly visible to Perl.
…		…
184		184
185	=cut	185	=cut
186		186
187	package IO::AIO;	187	package IO::AIO;
188		188
189	no warnings;	189	use Carp ();
190	use strict 'vars';	190
		191	use common::sense;
191		192
192	use base 'Exporter';	193	use base 'Exporter';
193		194
194	BEGIN {	195	BEGIN {
195	our $VERSION = '2.33';	196	our $VERSION = '3.31';
196		197
197	our @AIO_REQ = qw(aio_sendfile aio_read aio_write aio_open aio_close aio_stat	198	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	199	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	200	aio_scandir aio_symlink aio_readlink aio_sync aio_fsync
		201	aio_fdatasync aio_sync_file_range aio_pathsync aio_readahead
		202	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);	203	aio_nop aio_mknod aio_load aio_rmtree aio_mkdir aio_chown
		204	aio_chmod aio_utime aio_truncate
		205	aio_msync aio_mtouch);
		206
201	our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice aio_block));	207	our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice));
202	our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush	208	our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush
203	min_parallel max_parallel max_idle	209	min_parallel max_parallel max_idle
204	nreqs nready npending nthreads	210	nreqs nready npending nthreads
205	max_poll_time max_poll_reqs);	211	max_poll_time max_poll_reqs
		212	sendfile fadvise);
		213
		214	push @AIO_REQ, qw(aio_busy); # not exported
206		215
207	@IO::AIO::GRP::ISA = 'IO::AIO::REQ';	216	@IO::AIO::GRP::ISA = 'IO::AIO::REQ';
208		217
209	require XSLoader;	218	require XSLoader;
210	XSLoader::load ("IO::AIO", $VERSION);	219	XSLoader::load ("IO::AIO", $VERSION);
…		…
217	All the C<aio_*> calls are more or less thin wrappers around the syscall	226	All the C<aio_*> calls are more or less thin wrappers around the syscall
218	with the same name (sans C<aio_>). The arguments are similar or identical,	227	with the same name (sans C<aio_>). The arguments are similar or identical,
219	and they all accept an additional (and optional) C<$callback> argument	228	and they all accept an additional (and optional) C<$callback> argument
220	which must be a code reference. This code reference will get called with	229	which must be a code reference. This code reference will get called with
221	the syscall return code (e.g. most syscalls return C<-1> on error, unlike	230	the syscall return code (e.g. most syscalls return C<-1> on error, unlike
222	perl, which usually delivers "false") as it's sole argument when the given	231	perl, which usually delivers "false") as its sole argument after the given
223	syscall has been executed asynchronously.	232	syscall has been executed asynchronously.
224		233
225	All functions expecting a filehandle keep a copy of the filehandle	234	All functions expecting a filehandle keep a copy of the filehandle
226	internally until the request has finished.	235	internally until the request has finished.
227		236
…		…
241	your pathnames to the locale (or other) encoding in effect in the user	250	your pathnames to the locale (or other) encoding in effect in the user
242	environment, d) use Glib::filename_from_unicode on unicode filenames or e)	251	environment, d) use Glib::filename_from_unicode on unicode filenames or e)
243	use something else to ensure your scalar has the correct contents.	252	use something else to ensure your scalar has the correct contents.
244		253
245	This works, btw. independent of the internal UTF-8 bit, which IO::AIO	254	This works, btw. independent of the internal UTF-8 bit, which IO::AIO
246	handles correctly wether it is set or not.	255	handles correctly whether it is set or not.
247		256
248	=over 4	257	=over 4
249		258
250	=item $prev_pri = aioreq_pri [$pri]	259	=item $prev_pri = aioreq_pri [$pri]
251		260
…		…
271	aio_read $_[0], ..., sub {	280	aio_read $_[0], ..., sub {
272	...	281	...
273	};	282	};
274	};	283	};
275		284
		285
276	=item aioreq_nice $pri_adjust	286	=item aioreq_nice $pri_adjust
277		287
278	Similar to C<aioreq_pri>, but subtracts the given value from the current	288	Similar to C<aioreq_pri>, but subtracts the given value from the current
279	priority, so the effect is cumulative.	289	priority, so the effect is cumulative.
		290
280		291
281	=item aio_open $pathname, $flags, $mode, $callback->($fh)	292	=item aio_open $pathname, $flags, $mode, $callback->($fh)
282		293
283	Asynchronously open or create a file and call the callback with a newly	294	Asynchronously open or create a file and call the callback with a newly
284	created filehandle for the file.	295	created filehandle for the file.
…		…
305	} else {	316	} else {
306	die "open failed: $!\n";	317	die "open failed: $!\n";
307	}	318	}
308	};	319	};
309		320
		321
310	=item aio_close $fh, $callback->($status)	322	=item aio_close $fh, $callback->($status)
311		323
312	Asynchronously close a file and call the callback with the result	324	Asynchronously close a file and call the callback with the result
313	code. I<WARNING:> although accepted, you should not pass in a perl	325	code.
314	filehandle here, as perl will likely close the file descriptor another
315	time when the filehandle is destroyed. Normally, you can safely call perls
316	C<close> or just let filehandles go out of scope.
317		326
318	This is supposed to be a bug in the API, so that might change. It's	327	Unfortunately, you can't do this to perl. Perl I<insists> very strongly on
319	therefore best to avoid this function.	328	closing the file descriptor associated with the filehandle itself.
		329
		330	Therefore, C<aio_close> will not close the filehandle - instead it will
		331	use dup2 to overwrite the file descriptor with the write-end of a pipe
		332	(the pipe fd will be created on demand and will be cached).
		333
		334	Or in other words: the file descriptor will be closed, but it will not be
		335	free for reuse until the perl filehandle is closed.
		336
		337	=cut
320		338
321	=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)	339	=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
322		340
323	=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)	341	=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
324		342
325	Reads or writes C<length> bytes from the specified C<fh> and C<offset>	343	Reads or writes C<$length> bytes from or to the specified C<$fh> and
326	into the scalar given by C<data> and offset C<dataoffset> and calls the	344	C<$offset> into the scalar given by C<$data> and offset C<$dataoffset>
327	callback without the actual number of bytes read (or -1 on error, just	345	and calls the callback without the actual number of bytes read (or -1 on
328	like the syscall).	346	error, just like the syscall).
		347
		348	C<aio_read> will, like C<sysread>, shrink or grow the C<$data> scalar to
		349	offset plus the actual number of bytes read.
		350
		351	If C<$offset> is undefined, then the current file descriptor offset will
		352	be used (and updated), otherwise the file descriptor offset will not be
		353	changed by these calls.
		354
		355	If C<$length> is undefined in C<aio_write>, use the remaining length of
		356	C<$data>.
		357
		358	If C<$dataoffset> is less than zero, it will be counted from the end of
		359	C<$data>.
329		360
330	The C<$data> scalar I<MUST NOT> be modified in any way while the request	361	The C<$data> scalar I<MUST NOT> be modified in any way while the request
331	is outstanding. Modifying it can result in segfaults or WW3 (if the	362	is outstanding. Modifying it can result in segfaults or World War III (if
332	necessary/optional hardware is installed).	363	the necessary/optional hardware is installed).
333		364
334	Example: Read 15 bytes at offset 7 into scalar C<$buffer>, starting at	365	Example: Read 15 bytes at offset 7 into scalar C<$buffer>, starting at
335	offset C<0> within the scalar:	366	offset C<0> within the scalar:
336		367
337	aio_read $fh, 7, 15, $buffer, 0, sub {	368	aio_read $fh, 7, 15, $buffer, 0, sub {
338	$_[0] > 0 or die "read error: $!";	369	$_[0] > 0 or die "read error: $!";
339	print "read $_[0] bytes: <$buffer>\n";	370	print "read $_[0] bytes: <$buffer>\n";
340	};	371	};
		372
341		373
342	=item aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval)	374	=item aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval)
343		375
344	Tries to copy C<$length> bytes from C<$in_fh> to C<$out_fh>. It starts	376	Tries to copy C<$length> bytes from C<$in_fh> to C<$out_fh>. It starts
345	reading at byte offset C<$in_offset>, and starts writing at the current	377	reading at byte offset C<$in_offset>, and starts writing at the current
…		…
349		381
350	This call tries to make use of a native C<sendfile> syscall to provide	382	This call tries to make use of a native C<sendfile> syscall to provide
351	zero-copy operation. For this to work, C<$out_fh> should refer to a	383	zero-copy operation. For this to work, C<$out_fh> should refer to a
352	socket, and C<$in_fh> should refer to mmap'able file.	384	socket, and C<$in_fh> should refer to mmap'able file.
353		385
354	If the native sendfile call fails or is not implemented, it will be	386	If a native sendfile cannot be found or it fails with C<ENOSYS>,
		387	C<ENOTSUP>, C<EOPNOTSUPP>, C<EAFNOSUPPORT>, C<EPROTOTYPE> or C<ENOTSOCK>,
355	emulated, so you can call C<aio_sendfile> on any type of filehandle	388	it will be emulated, so you can call C<aio_sendfile> on any type of
356	regardless of the limitations of the operating system.	389	filehandle regardless of the limitations of the operating system.
357		390
358	Please note, however, that C<aio_sendfile> can read more bytes from	391	Please note, however, that C<aio_sendfile> can read more bytes from
359	C<$in_fh> than are written, and there is no way to find out how many	392	C<$in_fh> than are written, and there is no way to find out how many
360	bytes have been read from C<aio_sendfile> alone, as C<aio_sendfile> only	393	bytes have been read from C<aio_sendfile> alone, as C<aio_sendfile> only
361	provides the number of bytes written to C<$out_fh>. Only if the result	394	provides the number of bytes written to C<$out_fh>. Only if the result
362	value equals C<$length> one can assume that C<$length> bytes have been	395	value equals C<$length> one can assume that C<$length> bytes have been
363	read.	396	read.
		397
364		398
365	=item aio_readahead $fh,$offset,$length, $callback->($retval)	399	=item aio_readahead $fh,$offset,$length, $callback->($retval)
366		400
367	C<aio_readahead> populates the page cache with data from a file so that	401	C<aio_readahead> populates the page cache with data from a file so that
368	subsequent reads from that file will not block on disk I/O. The C<$offset>	402	subsequent reads from that file will not block on disk I/O. The C<$offset>
…		…
374	file. The current file offset of the file is left unchanged.	408	file. The current file offset of the file is left unchanged.
375		409
376	If that syscall doesn't exist (likely if your OS isn't Linux) it will be	410	If that syscall doesn't exist (likely if your OS isn't Linux) it will be
377	emulated by simply reading the data, which would have a similar effect.	411	emulated by simply reading the data, which would have a similar effect.
378		412
		413
379	=item aio_stat $fh_or_path, $callback->($status)	414	=item aio_stat $fh_or_path, $callback->($status)
380		415
381	=item aio_lstat $fh, $callback->($status)	416	=item aio_lstat $fh, $callback->($status)
382		417
383	Works like perl's C<stat> or C<lstat> in void context. The callback will	418	Works like perl's C<stat> or C<lstat> in void context. The callback will
…		…
396	aio_stat "/etc/passwd", sub {	431	aio_stat "/etc/passwd", sub {
397	$_[0] and die "stat failed: $!";	432	$_[0] and die "stat failed: $!";
398	print "size is ", -s _, "\n";	433	print "size is ", -s _, "\n";
399	};	434	};
400		435
		436
		437	=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
		438
		439	Works like perl's C<utime> function (including the special case of $atime
		440	and $mtime being undef). Fractional times are supported if the underlying
		441	syscalls support them.
		442
		443	When called with a pathname, uses utimes(2) if available, otherwise
		444	utime(2). If called on a file descriptor, uses futimes(2) if available,
		445	otherwise returns ENOSYS, so this is not portable.
		446
		447	Examples:
		448
		449	# set atime and mtime to current time (basically touch(1)):
		450	aio_utime "path", undef, undef;
		451	# set atime to current time and mtime to beginning of the epoch:
		452	aio_utime "path", time, undef; # undef==0
		453
		454
		455	=item aio_chown $fh_or_path, $uid, $gid, $callback->($status)
		456
		457	Works like perl's C<chown> function, except that C<undef> for either $uid
		458	or $gid is being interpreted as "do not change" (but -1 can also be used).
		459
		460	Examples:
		461
		462	# same as "chown root path" in the shell:
		463	aio_chown "path", 0, -1;
		464	# same as above:
		465	aio_chown "path", 0, undef;
		466
		467
		468	=item aio_truncate $fh_or_path, $offset, $callback->($status)
		469
		470	Works like truncate(2) or ftruncate(2).
		471
		472
		473	=item aio_chmod $fh_or_path, $mode, $callback->($status)
		474
		475	Works like perl's C<chmod> function.
		476
		477
401	=item aio_unlink $pathname, $callback->($status)	478	=item aio_unlink $pathname, $callback->($status)
402		479
403	Asynchronously unlink (delete) a file and call the callback with the	480	Asynchronously unlink (delete) a file and call the callback with the
404	result code.	481	result code.
405		482
		483
406	=item aio_mknod $path, $mode, $dev, $callback->($status)	484	=item aio_mknod $path, $mode, $dev, $callback->($status)
407		485
408	[EXPERIMENTAL]	486	[EXPERIMENTAL]
409		487
410	Asynchronously create a device node (or fifo). See mknod(2).	488	Asynchronously create a device node (or fifo). See mknod(2).
411		489
412	The only (POSIX-) portable way of calling this function is:	490	The only (POSIX-) portable way of calling this function is:
413		491
414	aio_mknod $path, IO::AIO::S_IFIFO \| $mode, 0, sub { ...	492	aio_mknod $path, IO::AIO::S_IFIFO \| $mode, 0, sub { ...
		493
415		494
416	=item aio_link $srcpath, $dstpath, $callback->($status)	495	=item aio_link $srcpath, $dstpath, $callback->($status)
417		496
418	Asynchronously create a new link to the existing object at C<$srcpath> at	497	Asynchronously create a new link to the existing object at C<$srcpath> at
419	the path C<$dstpath> and call the callback with the result code.	498	the path C<$dstpath> and call the callback with the result code.
420		499
		500
421	=item aio_symlink $srcpath, $dstpath, $callback->($status)	501	=item aio_symlink $srcpath, $dstpath, $callback->($status)
422		502
423	Asynchronously create a new symbolic link to the existing object at C<$srcpath> at	503	Asynchronously create a new symbolic link to the existing object at C<$srcpath> at
424	the path C<$dstpath> and call the callback with the result code.	504	the path C<$dstpath> and call the callback with the result code.
		505
425		506
426	=item aio_readlink $path, $callback->($link)	507	=item aio_readlink $path, $callback->($link)
427		508
428	Asynchronously read the symlink specified by C<$path> and pass it to	509	Asynchronously read the symlink specified by C<$path> and pass it to
429	the callback. If an error occurs, nothing or undef gets passed to the	510	the callback. If an error occurs, nothing or undef gets passed to the
430	callback.	511	callback.
431		512
		513
432	=item aio_rename $srcpath, $dstpath, $callback->($status)	514	=item aio_rename $srcpath, $dstpath, $callback->($status)
433		515
434	Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as	516	Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as
435	rename(2) and call the callback with the result code.	517	rename(2) and call the callback with the result code.
		518
436		519
437	=item aio_mkdir $pathname, $mode, $callback->($status)	520	=item aio_mkdir $pathname, $mode, $callback->($status)
438		521
439	Asynchronously mkdir (create) a directory and call the callback with	522	Asynchronously mkdir (create) a directory and call the callback with
440	the result code. C<$mode> will be modified by the umask at the time the	523	the result code. C<$mode> will be modified by the umask at the time the
441	request is executed, so do not change your umask.	524	request is executed, so do not change your umask.
442		525
		526
443	=item aio_rmdir $pathname, $callback->($status)	527	=item aio_rmdir $pathname, $callback->($status)
444		528
445	Asynchronously rmdir (delete) a directory and call the callback with the	529	Asynchronously rmdir (delete) a directory and call the callback with the
446	result code.	530	result code.
		531
447		532
448	=item aio_readdir $pathname, $callback->($entries)	533	=item aio_readdir $pathname, $callback->($entries)
449		534
450	Unlike the POSIX call of the same name, C<aio_readdir> reads an entire	535	Unlike the POSIX call of the same name, C<aio_readdir> reads an entire
451	directory (i.e. opendir + readdir + closedir). The entries will not be	536	directory (i.e. opendir + readdir + closedir). The entries will not be
452	sorted, and will B<NOT> include the C<.> and C<..> entries.	537	sorted, and will B<NOT> include the C<.> and C<..> entries.
453		538
454	The callback a single argument which is either C<undef> or an array-ref	539	The callback is passed a single argument which is either C<undef> or an
455	with the filenames.	540	array-ref with the filenames.
		541
		542
		543	=item aio_readdirx $pathname, $flags, $callback->($entries, $flags)
		544
		545	Quite similar to C<aio_readdir>, but the C<$flags> argument allows to tune
		546	behaviour and output format. In case of an error, C<$entries> will be
		547	C<undef>.
		548
		549	The flags are a combination of the following constants, ORed together (the
		550	flags will also be passed to the callback, possibly modified):
		551
		552	=over 4
		553
		554	=item IO::AIO::READDIR_DENTS
		555
		556	When this flag is off, then the callback gets an arrayref with of names
		557	only (as with C<aio_readdir>), otherwise it gets an arrayref with
		558	C<[$name, $type, $inode]> arrayrefs, each describing a single directory
		559	entry in more detail.
		560
		561	C<$name> is the name of the entry.
		562
		563	C<$type> is one of the C<IO::AIO::DT_xxx> constants:
		564
		565	C<IO::AIO::DT_UNKNOWN>, C<IO::AIO::DT_FIFO>, C<IO::AIO::DT_CHR>, C<IO::AIO::DT_DIR>,
		566	C<IO::AIO::DT_BLK>, C<IO::AIO::DT_REG>, C<IO::AIO::DT_LNK>, C<IO::AIO::DT_SOCK>,
		567	C<IO::AIO::DT_WHT>.
		568
		569	C<IO::AIO::DT_UNKNOWN> means just that: readdir does not know. If you need to
		570	know, you have to run stat yourself. Also, for speed reasons, the C<$type>
		571	scalars are read-only: you can not modify them.
		572
		573	C<$inode> is the inode number (which might not be exact on systems with 64
		574	bit inode numbers and 32 bit perls). This field has unspecified content on
		575	systems that do not deliver the inode information.
		576
		577	=item IO::AIO::READDIR_DIRS_FIRST
		578
		579	When this flag is set, then the names will be returned in an order where
		580	likely directories come first. This is useful when you need to quickly
		581	find directories, or you want to find all directories while avoiding to
		582	stat() each entry.
		583
		584	If the system returns type information in readdir, then this is used
		585	to find directories directly. Otherwise, likely directories are files
		586	beginning with ".", or otherwise files with no dots, of which files with
		587	short names are tried first.
		588
		589	=item IO::AIO::READDIR_STAT_ORDER
		590
		591	When this flag is set, then the names will be returned in an order
		592	suitable for stat()'ing each one. That is, when you plan to stat()
		593	all files in the given directory, then the returned order will likely
		594	be fastest.
		595
		596	If both this flag and C<IO::AIO::READDIR_DIRS_FIRST> are specified, then
		597	the likely dirs come first, resulting in a less optimal stat order.
		598
		599	=item IO::AIO::READDIR_FOUND_UNKNOWN
		600
		601	This flag should not be set when calling C<aio_readdirx>. Instead, it
		602	is being set by C<aio_readdirx>, when any of the C<$type>'s found were
		603	C<IO::AIO::DT_UNKNOWN>. The absense of this flag therefore indicates that all
		604	C<$type>'s are known, which can be used to speed up some algorithms.
		605
		606	=back
		607
456		608
457	=item aio_load $path, $data, $callback->($status)	609	=item aio_load $path, $data, $callback->($status)
458		610
459	This is a composite request that tries to fully load the given file into	611	This is a composite request that tries to fully load the given file into
460	memory. Status is the same as with aio_read.	612	memory. Status is the same as with aio_read.
461		613
462	=cut	614	=cut
463		615
464	sub aio_load($$;$) {	616	sub aio_load($$;$) {
465	aio_block {
466	my ($path, undef, $cb) = @_;	617	my ($path, undef, $cb) = @_;
467	my $data = \$_[1];	618	my $data = \$_[1];
468		619
469	my $pri = aioreq_pri;	620	my $pri = aioreq_pri;
470	my $grp = aio_group $cb;	621	my $grp = aio_group $cb;
		622
		623	aioreq_pri $pri;
		624	add $grp aio_open $path, O_RDONLY, 0, sub {
		625	my $fh = shift
		626	or return $grp->result (-1);
471		627
472	aioreq_pri $pri;	628	aioreq_pri $pri;
473	add $grp aio_open $path, O_RDONLY, 0, sub {
474	my $fh = shift
475	or return $grp->result (-1);
476
477	aioreq_pri $pri;
478	add $grp aio_read $fh, 0, (-s $fh), $$data, 0, sub {	629	add $grp aio_read $fh, 0, (-s $fh), $$data, 0, sub {
479	$grp->result ($_[0]);	630	$grp->result ($_[0]);
480	};
481	};	631	};
482
483	$grp
484	}	632	};
		633
		634	$grp
485	}	635	}
486		636
487	=item aio_copy $srcpath, $dstpath, $callback->($status)	637	=item aio_copy $srcpath, $dstpath, $callback->($status)
488		638
489	Try to copy the I<file> (directories not supported as either source or	639	Try to copy the I<file> (directories not supported as either source or
490	destination) from C<$srcpath> to C<$dstpath> and call the callback with	640	destination) from C<$srcpath> to C<$dstpath> and call the callback with
491	the C<0> (error) or C<-1> ok.	641	a status of C<0> (ok) or C<-1> (error, see C<$!>).
492		642
493	This is a composite request that it creates the destination file with	643	This is a composite request that creates the destination file with
494	mode 0200 and copies the contents of the source file into it using	644	mode 0200 and copies the contents of the source file into it using
495	C<aio_sendfile>, followed by restoring atime, mtime, access mode and	645	C<aio_sendfile>, followed by restoring atime, mtime, access mode and
496	uid/gid, in that order.	646	uid/gid, in that order.
497		647
498	If an error occurs, the partial destination file will be unlinked, if	648	If an error occurs, the partial destination file will be unlinked, if
…		…
500	errors are being ignored.	650	errors are being ignored.
501		651
502	=cut	652	=cut
503		653
504	sub aio_copy($$;$) {	654	sub aio_copy($$;$) {
505	aio_block {
506	my ($src, $dst, $cb) = @_;	655	my ($src, $dst, $cb) = @_;
507		656
508	my $pri = aioreq_pri;	657	my $pri = aioreq_pri;
509	my $grp = aio_group $cb;	658	my $grp = aio_group $cb;
510		659
511	aioreq_pri $pri;	660	aioreq_pri $pri;
512	add $grp aio_open $src, O_RDONLY, 0, sub {	661	add $grp aio_open $src, O_RDONLY, 0, sub {
513	if (my $src_fh = $_[0]) {	662	if (my $src_fh = $_[0]) {
514	my @stat = stat $src_fh;	663	my @stat = stat $src_fh; # hmm, might block over nfs?
515		664
516	aioreq_pri $pri;	665	aioreq_pri $pri;
517	add $grp aio_open $dst, O_CREAT \| O_WRONLY \| O_TRUNC, 0200, sub {	666	add $grp aio_open $dst, O_CREAT \| O_WRONLY \| O_TRUNC, 0200, sub {
518	if (my $dst_fh = $_[0]) {	667	if (my $dst_fh = $_[0]) {
519	aioreq_pri $pri;	668	aioreq_pri $pri;
520	add $grp aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub {	669	add $grp aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub {
521	if ($_[0] == $stat[7]) {	670	if ($_[0] == $stat[7]) {
522	$grp->result (0);	671	$grp->result (0);
523	close $src_fh;	672	close $src_fh;
524		673
525	# those should not normally block. should. should.
526	utime $stat[8], $stat[9], $dst;
527	chmod $stat[2] & 07777, $dst_fh;
528	chown $stat[4], $stat[5], $dst_fh;
529	close $dst_fh;
530	} else {	674	my $ch = sub {
531	$grp->result (-1);
532	close $src_fh;
533	close $dst_fh;
534
535	aioreq $pri;	675	aioreq_pri $pri;
		676	add $grp aio_chmod $dst_fh, $stat[2] & 07777, sub {
		677	aioreq_pri $pri;
		678	add $grp aio_chown $dst_fh, $stat[4], $stat[5], sub {
		679	aioreq_pri $pri;
536	add $grp aio_unlink $dst;	680	add $grp aio_close $dst_fh;
		681	}
		682	};
537	}	683	};
		684
		685	aioreq_pri $pri;
		686	add $grp aio_utime $dst_fh, $stat[8], $stat[9], sub {
		687	if ($_[0] < 0 && $! == ENOSYS) {
		688	aioreq_pri $pri;
		689	add $grp aio_utime $dst, $stat[8], $stat[9], $ch;
		690	} else {
		691	$ch->();
		692	}
		693	};
		694	} else {
		695	$grp->result (-1);
		696	close $src_fh;
		697	close $dst_fh;
		698
		699	aioreq $pri;
		700	add $grp aio_unlink $dst;
538	};	701	}
539	} else {
540	$grp->result (-1);
541	}	702	};
		703	} else {
		704	$grp->result (-1);
542	},	705	}
543
544	} else {
545	$grp->result (-1);
546	}	706	},
		707
		708	} else {
		709	$grp->result (-1);
547	};	710	}
548
549	$grp
550	}	711	};
		712
		713	$grp
551	}	714	}
552		715
553	=item aio_move $srcpath, $dstpath, $callback->($status)	716	=item aio_move $srcpath, $dstpath, $callback->($status)
554		717
555	Try to move the I<file> (directories not supported as either source or	718	Try to move the I<file> (directories not supported as either source or
556	destination) from C<$srcpath> to C<$dstpath> and call the callback with	719	destination) from C<$srcpath> to C<$dstpath> and call the callback with
557	the C<0> (error) or C<-1> ok.	720	a status of C<0> (ok) or C<-1> (error, see C<$!>).
558		721
559	This is a composite request that tries to rename(2) the file first. If	722	This is a composite request that tries to rename(2) the file first; if
560	rename files with C<EXDEV>, it copies the file with C<aio_copy> and, if	723	rename fails with C<EXDEV>, it copies the file with C<aio_copy> and, if
561	that is successful, unlinking the C<$srcpath>.	724	that is successful, unlinks the C<$srcpath>.
562		725
563	=cut	726	=cut
564		727
565	sub aio_move($$;$) {	728	sub aio_move($$;$) {
566	aio_block {
567	my ($src, $dst, $cb) = @_;	729	my ($src, $dst, $cb) = @_;
568		730
569	my $pri = aioreq_pri;	731	my $pri = aioreq_pri;
570	my $grp = aio_group $cb;	732	my $grp = aio_group $cb;
571		733
572	aioreq_pri $pri;	734	aioreq_pri $pri;
573	add $grp aio_rename $src, $dst, sub {	735	add $grp aio_rename $src, $dst, sub {
574	if ($_[0] && $! == EXDEV) {	736	if ($_[0] && $! == EXDEV) {
575	aioreq_pri $pri;	737	aioreq_pri $pri;
576	add $grp aio_copy $src, $dst, sub {	738	add $grp aio_copy $src, $dst, sub {
577	$grp->result ($_[0]);
578
579	if (!$_[0]) {
580	aioreq_pri $pri;
581	add $grp aio_unlink $src;
582	}
583	};
584	} else {
585	$grp->result ($_[0]);	739	$grp->result ($_[0]);
		740
		741	if (!$_[0]) {
		742	aioreq_pri $pri;
		743	add $grp aio_unlink $src;
		744	}
586	}	745	};
		746	} else {
		747	$grp->result ($_[0]);
587	};	748	}
588
589	$grp
590	}	749	};
		750
		751	$grp
591	}	752	}
592		753
593	=item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs)	754	=item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs)
594		755
595	Scans a directory (similar to C<aio_readdir>) but additionally tries to	756	Scans a directory (similar to C<aio_readdir>) but additionally tries to
…		…
615		776
616	Implementation notes.	777	Implementation notes.
617		778
618	The C<aio_readdir> cannot be avoided, but C<stat()>'ing every entry can.	779	The C<aio_readdir> cannot be avoided, but C<stat()>'ing every entry can.
619		780
		781	If readdir returns file type information, then this is used directly to
		782	find directories.
		783
620	After reading the directory, the modification time, size etc. of the	784	Otherwise, after reading the directory, the modification time, size etc.
621	directory before and after the readdir is checked, and if they match (and	785	of the directory before and after the readdir is checked, and if they
622	isn't the current time), the link count will be used to decide how many	786	match (and isn't the current time), the link count will be used to decide
623	entries are directories (if >= 2). Otherwise, no knowledge of the number	787	how many entries are directories (if >= 2). Otherwise, no knowledge of the
624	of subdirectories will be assumed.	788	number of subdirectories will be assumed.
625		789
626	Then entries will be sorted into likely directories (everything without	790	Then entries will be sorted into likely directories a non-initial dot
627	a non-initial dot currently) and likely non-directories (everything	791	currently) and likely non-directories (see C<aio_readdirx>). Then every
628	else). Then every entry plus an appended C</.> will be C<stat>'ed,	792	entry plus an appended C</.> will be C<stat>'ed, likely directories first,
629	likely directories first. If that succeeds, it assumes that the entry	793	in order of their inode numbers. If that succeeds, it assumes that the
630	is a directory or a symlink to directory (which will be checked	794	entry is a directory or a symlink to directory (which will be checked
631	seperately). This is often faster than stat'ing the entry itself because	795	seperately). This is often faster than stat'ing the entry itself because
632	filesystems might detect the type of the entry without reading the inode	796	filesystems might detect the type of the entry without reading the inode
633	data (e.g. ext2fs filetype feature).	797	data (e.g. ext2fs filetype feature), even on systems that cannot return
		798	the filetype information on readdir.
634		799
635	If the known number of directories (link count - 2) has been reached, the	800	If the known number of directories (link count - 2) has been reached, the
636	rest of the entries is assumed to be non-directories.	801	rest of the entries is assumed to be non-directories.
637		802
638	This only works with certainty on POSIX (= UNIX) filesystems, which	803	This only works with certainty on POSIX (= UNIX) filesystems, which
…		…
643	directory counting heuristic.	808	directory counting heuristic.
644		809
645	=cut	810	=cut
646		811
647	sub aio_scandir($$;$) {	812	sub aio_scandir($$;$) {
648	aio_block {
649	my ($path, $maxreq, $cb) = @_;	813	my ($path, $maxreq, $cb) = @_;
650		814
651	my $pri = aioreq_pri;	815	my $pri = aioreq_pri;
652		816
653	my $grp = aio_group $cb;	817	my $grp = aio_group $cb;
654		818
655	$maxreq = 4 if $maxreq <= 0;	819	$maxreq = 4 if $maxreq <= 0;
656		820
657	# stat once	821	# stat once
		822	aioreq_pri $pri;
		823	add $grp aio_stat $path, sub {
		824	return $grp->result () if $_[0];
		825	my $now = time;
		826	my $hash1 = join ":", (stat _)[0,1,3,7,9];
		827
		828	# read the directory entries
658	aioreq_pri $pri;	829	aioreq_pri $pri;
659	add $grp aio_stat $path, sub {	830	add $grp aio_readdirx $path, READDIR_DIRS_FIRST, sub {
		831	my $entries = shift
660	return $grp->result () if $_[0];	832	or return $grp->result ();
661	my $now = time;
662	my $hash1 = join ":", (stat _)[0,1,3,7,9];
663		833
664	# read the directory entries	834	# stat the dir another time
665	aioreq_pri $pri;	835	aioreq_pri $pri;
666	add $grp aio_readdir $path, sub {
667	my $entries = shift
668	or return $grp->result ();
669
670	# stat the dir another time
671	aioreq_pri $pri;
672	add $grp aio_stat $path, sub {	836	add $grp aio_stat $path, sub {
673	my $hash2 = join ":", (stat _)[0,1,3,7,9];	837	my $hash2 = join ":", (stat _)[0,1,3,7,9];
674		838
675	my $ndirs;	839	my $ndirs;
676		840
677	# take the slow route if anything looks fishy	841	# take the slow route if anything looks fishy
678	if ($hash1 ne $hash2 or (stat _)[9] == $now) {	842	if ($hash1 ne $hash2 or (stat _)[9] == $now) {
679	$ndirs = -1;	843	$ndirs = -1;
680	} else {	844	} else {
681	# if nlink == 2, we are finished	845	# if nlink == 2, we are finished
682	# on non-posix-fs's, we rely on nlink < 2	846	# for non-posix-fs's, we rely on nlink < 2
683	$ndirs = (stat _)[3] - 2	847	$ndirs = (stat _)[3] - 2
684	or return $grp->result ([], $entries);	848	or return $grp->result ([], $entries);
685	}	849	}
686		850
687	# sort into likely dirs and likely nondirs
688	# dirs == files without ".", short entries first
689	$entries = [map $_->[0],
690	sort { $b->[1] cmp $a->[1] }
691	map [$_, sprintf "%s%04d", (/.\./ ? "1" : "0"), length],
692	@$entries];
693
694	my (@dirs, @nondirs);	851	my (@dirs, @nondirs);
695		852
696	my $statgrp = add $grp aio_group sub {	853	my $statgrp = add $grp aio_group sub {
697	$grp->result (\@dirs, \@nondirs);	854	$grp->result (\@dirs, \@nondirs);
698	};	855	};
699		856
700	limit $statgrp $maxreq;	857	limit $statgrp $maxreq;
701	feed $statgrp sub {	858	feed $statgrp sub {
702	return unless @$entries;	859	return unless @$entries;
703	my $entry = pop @$entries;	860	my $entry = shift @$entries;
704		861
705	aioreq_pri $pri;	862	aioreq_pri $pri;
706	add $statgrp aio_stat "$path/$entry/.", sub {	863	add $statgrp aio_stat "$path/$entry/.", sub {
707	if ($_[0] < 0) {	864	if ($_[0] < 0) {
708	push @nondirs, $entry;	865	push @nondirs, $entry;
709	} else {	866	} else {
710	# need to check for real directory	867	# need to check for real directory
711	aioreq_pri $pri;	868	aioreq_pri $pri;
712	add $statgrp aio_lstat "$path/$entry", sub {	869	add $statgrp aio_lstat "$path/$entry", sub {
713	if (-d _) {	870	if (-d _) {
714	push @dirs, $entry;	871	push @dirs, $entry;
715		872
716	unless (--$ndirs) {	873	unless (--$ndirs) {
717	push @nondirs, @$entries;	874	push @nondirs, @$entries;
718	feed $statgrp;	875	feed $statgrp;
719	}
720	} else {
721	push @nondirs, $entry;
722	}	876	}
		877	} else {
		878	push @nondirs, $entry;
723	}	879	}
724	}	880	}
725	};	881	}
726	};	882	};
727	};	883	};
728	};	884	};
729	};	885	};
730
731	$grp
732	}	886	};
		887
		888	$grp
733	}	889	}
734		890
735	=item aio_rmtree $path, $callback->($status)	891	=item aio_rmtree $path, $callback->($status)
736		892
737	Delete a directory tree starting (and including) C<$path>, return the	893	Delete a directory tree starting (and including) C<$path>, return the
…		…
741		897
742	=cut	898	=cut
743		899
744	sub aio_rmtree;	900	sub aio_rmtree;
745	sub aio_rmtree($;$) {	901	sub aio_rmtree($;$) {
746	aio_block {
747	my ($path, $cb) = @_;	902	my ($path, $cb) = @_;
748		903
749	my $pri = aioreq_pri;	904	my $pri = aioreq_pri;
750	my $grp = aio_group $cb;	905	my $grp = aio_group $cb;
751		906
752	aioreq_pri $pri;	907	aioreq_pri $pri;
753	add $grp aio_scandir $path, 0, sub {	908	add $grp aio_scandir $path, 0, sub {
754	my ($dirs, $nondirs) = @_;	909	my ($dirs, $nondirs) = @_;
755		910
756	my $dirgrp = aio_group sub {	911	my $dirgrp = aio_group sub {
757	add $grp aio_rmdir $path, sub {	912	add $grp aio_rmdir $path, sub {
758	$grp->result ($_[0]);	913	$grp->result ($_[0]);
759	};
760	};	914	};
761
762	(aioreq_pri $pri), add $dirgrp aio_rmtree "$path/$_" for @$dirs;
763	(aioreq_pri $pri), add $dirgrp aio_unlink "$path/$_" for @$nondirs;
764
765	add $grp $dirgrp;
766	};	915	};
767		916
768	$grp	917	(aioreq_pri $pri), add $dirgrp aio_rmtree "$path/$_" for @$dirs;
		918	(aioreq_pri $pri), add $dirgrp aio_unlink "$path/$_" for @$nondirs;
		919
		920	add $grp $dirgrp;
769	}	921	};
		922
		923	$grp
770	}	924	}
		925
		926	=item aio_sync $callback->($status)
		927
		928	Asynchronously call sync and call the callback when finished.
771		929
772	=item aio_fsync $fh, $callback->($status)	930	=item aio_fsync $fh, $callback->($status)
773		931
774	Asynchronously call fsync on the given filehandle and call the callback	932	Asynchronously call fsync on the given filehandle and call the callback
775	with the fsync result code.	933	with the fsync result code.
…		…
779	Asynchronously call fdatasync on the given filehandle and call the	937	Asynchronously call fdatasync on the given filehandle and call the
780	callback with the fdatasync result code.	938	callback with the fdatasync result code.
781		939
782	If this call isn't available because your OS lacks it or it couldn't be	940	If this call isn't available because your OS lacks it or it couldn't be
783	detected, it will be emulated by calling C<fsync> instead.	941	detected, it will be emulated by calling C<fsync> instead.
		942
		943	=item aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status)
		944
		945	Sync the data portion of the file specified by C<$offset> and C<$length>
		946	to disk (but NOT the metadata), by calling the Linux-specific
		947	sync_file_range call. If sync_file_range is not available or it returns
		948	ENOSYS, then fdatasync or fsync is being substituted.
		949
		950	C<$flags> can be a combination of C<IO::AIO::SYNC_FILE_RANGE_WAIT_BEFORE>,
		951	C<IO::AIO::SYNC_FILE_RANGE_WRITE> and
		952	C<IO::AIO::SYNC_FILE_RANGE_WAIT_AFTER>: refer to the sync_file_range
		953	manpage for details.
		954
		955	=item aio_pathsync $path, $callback->($status)
		956
		957	This request tries to open, fsync and close the given path. This is a
		958	composite request intended to sync directories after directory operations
		959	(E.g. rename). This might not work on all operating systems or have any
		960	specific effect, but usually it makes sure that directory changes get
		961	written to disc. It works for anything that can be opened for read-only,
		962	not just directories.
		963
		964	Future versions of this function might fall back to other methods when
		965	C<fsync> on the directory fails (such as calling C<sync>).
		966
		967	Passes C<0> when everything went ok, and C<-1> on error.
		968
		969	=cut
		970
		971	sub aio_pathsync($;$) {
		972	my ($path, $cb) = @_;
		973
		974	my $pri = aioreq_pri;
		975	my $grp = aio_group $cb;
		976
		977	aioreq_pri $pri;
		978	add $grp aio_open $path, O_RDONLY, 0, sub {
		979	my ($fh) = @_;
		980	if ($fh) {
		981	aioreq_pri $pri;
		982	add $grp aio_fsync $fh, sub {
		983	$grp->result ($_[0]);
		984
		985	aioreq_pri $pri;
		986	add $grp aio_close $fh;
		987	};
		988	} else {
		989	$grp->result (-1);
		990	}
		991	};
		992
		993	$grp
		994	}
		995
		996	=item aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
		997
		998	This is a rather advanced IO::AIO call, which only works on mmap(2)ed
		999	scalars (see the L<Sys::Mmap> or L<Mmap> modules for details on this, note
		1000	that the scalar must only be modified in-place while an aio operation is
		1001	pending on it).
		1002
		1003	It calls the C<msync> function of your OS, if available, with the memory
		1004	area starting at C<$offset> in the string and ending C<$length> bytes
		1005	later. If C<$length> is negative, counts from the end, and if C<$length>
		1006	is C<undef>, then it goes till the end of the string. The flags can be
		1007	a combination of C<IO::AIO::MS_ASYNC>, C<IO::AIO::MS_INVALIDATE> and
		1008	C<IO::AIO::MS_SYNC>.
		1009
		1010	=item aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
		1011
		1012	This is a rather advanced IO::AIO call, which works best on mmap(2)ed
		1013	scalars.
		1014
		1015	It touches (reads or writes) all memory pages in the specified
		1016	range inside the scalar. All caveats and parameters are the same
		1017	as for C<aio_msync>, above, except for flags, which must be either
		1018	C<0> (which reads all pages and ensures they are instantiated) or
		1019	C<IO::AIO::MT_MODIFY>, which modifies the memory page s(by reading and
		1020	writing an octet from it, which dirties the page).
784		1021
785	=item aio_group $callback->(...)	1022	=item aio_group $callback->(...)
786		1023
787	This is a very special aio request: Instead of doing something, it is a	1024	This is a very special aio request: Instead of doing something, it is a
788	container for other aio requests, which is useful if you want to bundle	1025	container for other aio requests, which is useful if you want to bundle
…		…
838	=item cancel $req	1075	=item cancel $req
839		1076
840	Cancels the request, if possible. Has the effect of skipping execution	1077	Cancels the request, if possible. Has the effect of skipping execution
841	when entering the B<execute> state and skipping calling the callback when	1078	when entering the B<execute> state and skipping calling the callback when
842	entering the the B<result> state, but will leave the request otherwise	1079	entering the the B<result> state, but will leave the request otherwise
843	untouched. That means that requests that currently execute will not be	1080	untouched (with the exception of readdir). That means that requests that
844	stopped and resources held by the request will not be freed prematurely.	1081	currently execute will not be stopped and resources held by the request
		1082	will not be freed prematurely.
845		1083
846	=item cb $req $callback->(...)	1084	=item cb $req $callback->(...)
847		1085
848	Replace (or simply set) the callback registered to the request.	1086	Replace (or simply set) the callback registered to the request.
849		1087
…		…
900	Their lifetime, simplified, looks like this: when they are empty, they	1138	Their lifetime, simplified, looks like this: when they are empty, they
901	will finish very quickly. If they contain only requests that are in the	1139	will finish very quickly. If they contain only requests that are in the
902	C<done> state, they will also finish. Otherwise they will continue to	1140	C<done> state, they will also finish. Otherwise they will continue to
903	exist.	1141	exist.
904		1142
905	That means after creating a group you have some time to add requests. And	1143	That means after creating a group you have some time to add requests
906	in the callbacks of those requests, you can add further requests to the	1144	(precisely before the callback has been invoked, which is only done within
907	group. And only when all those requests have finished will the the group	1145	the C<poll_cb>). And in the callbacks of those requests, you can add
908	itself finish.	1146	further requests to the group. And only when all those requests have
		1147	finished will the the group itself finish.
909		1148
910	=over 4	1149	=over 4
911		1150
912	=item add $grp ...	1151	=item add $grp ...
913		1152
…		…
922	=item $grp->cancel_subs	1161	=item $grp->cancel_subs
923		1162
924	Cancel all subrequests and clears any feeder, but not the group request	1163	Cancel all subrequests and clears any feeder, but not the group request
925	itself. Useful when you queued a lot of events but got a result early.	1164	itself. Useful when you queued a lot of events but got a result early.
926		1165
		1166	The group request will finish normally (you cannot add requests to the
		1167	group).
		1168
927	=item $grp->result (...)	1169	=item $grp->result (...)
928		1170
929	Set the result value(s) that will be passed to the group callback when all	1171	Set the result value(s) that will be passed to the group callback when all
930	subrequests have finished and set thre groups errno to the current value	1172	subrequests have finished and set the groups errno to the current value
931	of errno (just like calling C<errno> without an error number). By default,	1173	of errno (just like calling C<errno> without an error number). By default,
932	no argument will be passed and errno is zero.	1174	no argument will be passed and errno is zero.
933		1175
934	=item $grp->errno ([$errno])	1176	=item $grp->errno ([$errno])
935		1177
…		…
946	=item feed $grp $callback->($grp)	1188	=item feed $grp $callback->($grp)
947		1189
948	Sets a feeder/generator on this group: every group can have an attached	1190	Sets a feeder/generator on this group: every group can have an attached
949	generator that generates requests if idle. The idea behind this is that,	1191	generator that generates requests if idle. The idea behind this is that,
950	although you could just queue as many requests as you want in a group,	1192	although you could just queue as many requests as you want in a group,
951	this might starve other requests for a potentially long time. For	1193	this might starve other requests for a potentially long time. For example,
952	example, C<aio_scandir> might generate hundreds of thousands C<aio_stat>	1194	C<aio_scandir> might generate hundreds of thousands C<aio_stat> requests,
953	requests, delaying any later requests for a long time.	1195	delaying any later requests for a long time.
954		1196
955	To avoid this, and allow incremental generation of requests, you can	1197	To avoid this, and allow incremental generation of requests, you can
956	instead a group and set a feeder on it that generates those requests. The	1198	instead a group and set a feeder on it that generates those requests. The
957	feed callback will be called whenever there are few enough (see C<limit>,	1199	feed callback will be called whenever there are few enough (see C<limit>,
958	below) requests active in the group itself and is expected to queue more	1200	below) requests active in the group itself and is expected to queue more
…		…
962	not impose any limits).	1204	not impose any limits).
963		1205
964	If the feed does not queue more requests when called, it will be	1206	If the feed does not queue more requests when called, it will be
965	automatically removed from the group.	1207	automatically removed from the group.
966		1208
967	If the feed limit is C<0>, it will be set to C<2> automatically.	1209	If the feed limit is C<0> when this method is called, it will be set to
		1210	C<2> automatically.
968		1211
969	Example:	1212	Example:
970		1213
971	# stat all files in @files, but only ever use four aio requests concurrently:	1214	# stat all files in @files, but only ever use four aio requests concurrently:
972		1215
…		…
984	Sets the feeder limit for the group: The feeder will be called whenever	1227	Sets the feeder limit for the group: The feeder will be called whenever
985	the group contains less than this many requests.	1228	the group contains less than this many requests.
986		1229
987	Setting the limit to C<0> will pause the feeding process.	1230	Setting the limit to C<0> will pause the feeding process.
988		1231
		1232	The default value for the limit is C<0>, but note that setting a feeder
		1233	automatically bumps it up to C<2>.
		1234
989	=back	1235	=back
990		1236
991	=head2 SUPPORT FUNCTIONS	1237	=head2 SUPPORT FUNCTIONS
992		1238
993	=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION	1239	=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION
…		…
995	=over 4	1241	=over 4
996		1242
997	=item $fileno = IO::AIO::poll_fileno	1243	=item $fileno = IO::AIO::poll_fileno
998		1244
999	Return the I<request result pipe file descriptor>. This filehandle must be	1245	Return the I<request result pipe file descriptor>. This filehandle must be
1000	polled for reading by some mechanism outside this module (e.g. Event or	1246	polled for reading by some mechanism outside this module (e.g. EV, Glib,
1001	select, see below or the SYNOPSIS). If the pipe becomes readable you have	1247	select and so on, see below or the SYNOPSIS). If the pipe becomes readable
1002	to call C<poll_cb> to check the results.	1248	you have to call C<poll_cb> to check the results.
1003		1249
1004	See C<poll_cb> for an example.	1250	See C<poll_cb> for an example.
1005		1251
1006	=item IO::AIO::poll_cb	1252	=item IO::AIO::poll_cb
1007		1253
1008	Process some outstanding events on the result pipe. You have to call this	1254	Process some outstanding events on the result pipe. You have to call this
1009	regularly. Returns the number of events processed. Returns immediately	1255	regularly. Returns C<0> if all events could be processed, or C<-1> if it
		1256	returned earlier for whatever reason. Returns immediately when no events
1010	when no events are outstanding. The amount of events processed depends on	1257	are outstanding. The amount of events processed depends on the settings of
1011	the settings of C<IO::AIO::max_poll_req> and C<IO::AIO::max_poll_time>.	1258	C<IO::AIO::max_poll_req> and C<IO::AIO::max_poll_time>.
1012		1259
1013	If not all requests were processed for whatever reason, the filehandle	1260	If not all requests were processed for whatever reason, the filehandle
1014	will still be ready when C<poll_cb> returns.	1261	will still be ready when C<poll_cb> returns, so normally you don't have to
		1262	do anything special to have it called later.
1015		1263
1016	Example: Install an Event watcher that automatically calls	1264	Example: Install an Event watcher that automatically calls
1017	IO::AIO::poll_cb with high priority:	1265	IO::AIO::poll_cb with high priority (more examples can be found in the
		1266	SYNOPSIS section, at the top of this document):
1018		1267
1019	Event->io (fd => IO::AIO::poll_fileno,	1268	Event->io (fd => IO::AIO::poll_fileno,
1020	poll => 'r', async => 1,	1269	poll => 'r', async => 1,
1021	cb => \&IO::AIO::poll_cb);	1270	cb => \&IO::AIO::poll_cb);
1022		1271
…		…
1133		1382
1134	The default is probably ok in most situations, especially if thread	1383	The default is probably ok in most situations, especially if thread
1135	creation is fast. If thread creation is very slow on your system you might	1384	creation is fast. If thread creation is very slow on your system you might
1136	want to use larger values.	1385	want to use larger values.
1137		1386
1138	=item $oldmaxreqs = IO::AIO::max_outstanding $maxreqs	1387	=item IO::AIO::max_outstanding $maxreqs
1139		1388
1140	This is a very bad function to use in interactive programs because it	1389	This is a very bad function to use in interactive programs because it
1141	blocks, and a bad way to reduce concurrency because it is inexact: Better	1390	blocks, and a bad way to reduce concurrency because it is inexact: Better
1142	use an C<aio_group> together with a feed callback.	1391	use an C<aio_group> together with a feed callback.
1143		1392
1144	Sets the maximum number of outstanding requests to C<$nreqs>. If you	1393	Sets the maximum number of outstanding requests to C<$nreqs>. If you
1145	to queue up more than this number of requests, the next call to the	1394	do queue up more than this number of requests, the next call to the
1146	C<poll_cb> (and C<poll_some> and other functions calling C<poll_cb>)	1395	C<poll_cb> (and C<poll_some> and other functions calling C<poll_cb>)
1147	function will block until the limit is no longer exceeded.	1396	function will block until the limit is no longer exceeded.
1148		1397
1149	The default value is very large, so there is no practical limit on the	1398	The default value is very large, so there is no practical limit on the
1150	number of outstanding requests.	1399	number of outstanding requests.
1151		1400
1152	You can still queue as many requests as you want. Therefore,	1401	You can still queue as many requests as you want. Therefore,
1153	C<max_oustsanding> is mainly useful in simple scripts (with low values) or	1402	C<max_outstanding> is mainly useful in simple scripts (with low values) or
1154	as a stop gap to shield against fatal memory overflow (with large values).	1403	as a stop gap to shield against fatal memory overflow (with large values).
1155		1404
1156	=back	1405	=back
1157		1406
1158	=head3 STATISTICAL INFORMATION	1407	=head3 STATISTICAL INFORMATION
…		…
1179	Returns the number of requests currently in the pending state (executed,	1428	Returns the number of requests currently in the pending state (executed,
1180	but not yet processed by poll_cb).	1429	but not yet processed by poll_cb).
1181		1430
1182	=back	1431	=back
1183		1432
		1433	=head3 MISCELLANEOUS FUNCTIONS
		1434
		1435	IO::AIO implements some functions that might be useful, but are not
		1436	asynchronous.
		1437
		1438	=over 4
		1439
		1440	=item IO::AIO::sendfile $ofh, $ifh, $offset, $count
		1441
		1442	Calls the C<eio_sendfile_sync> function, which is like C<aio_sendfile>,
		1443	but is blocking (this makes most sense if you know the input data is
		1444	likely cached already and the output filehandle is set to non-blocking
		1445	operations).
		1446
		1447	Returns the number of bytes copied, or C<-1> on error.
		1448
		1449	=item IO::AIO::fadvise $fh, $offset, $len, $advice
		1450
		1451	Simply calls the C<posix_fadvise> function (see it's
		1452	manpage for details). The following advice constants are
		1453	avaiable: C<IO::AIO::FADV_NORMAL>, C<IO::AIO::FADV_SEQUENTIAL>,
		1454	C<IO::AIO::FADV_RANDOM>, C<IO::AIO::FADV_NOREUSE>,
		1455	C<IO::AIO::FADV_WILLNEED>, C<IO::AIO::FADV_DONTNEED>.
		1456
		1457	On systems that do not implement C<posix_fadvise>, this function returns
		1458	ENOSYS, otherwise the return value of C<posix_fadvise>.
		1459
		1460	=back
		1461
1184	=cut	1462	=cut
1185
1186	# support function to convert a fd into a perl filehandle
1187	sub _fd2fh {
1188	return undef if $_[0] < 0;
1189
1190	# try to generate nice filehandles
1191	my $sym = "IO::AIO::fd#$_[0]";
1192	local *$sym;
1193
1194	open *$sym, "+<&=$_[0]" # usually works under any unix
1195	or open *$sym, "<&=$_[0]" # cygwin needs this
1196	or open *$sym, ">&=$_[0]" # or this
1197	or return undef;
1198
1199	*$sym
1200	}
1201		1463
1202	min_parallel 8;	1464	min_parallel 8;
1203		1465
1204	END { flush }	1466	END { flush }
1205		1467
…		…
1229	bytes of memory. In addition, stat requests need a stat buffer (possibly	1491	bytes of memory. In addition, stat requests need a stat buffer (possibly
1230	a few hundred bytes), readdir requires a result buffer and so on. Perl	1492	a few hundred bytes), readdir requires a result buffer and so on. Perl
1231	scalars and other data passed into aio requests will also be locked and	1493	scalars and other data passed into aio requests will also be locked and
1232	will consume memory till the request has entered the done state.	1494	will consume memory till the request has entered the done state.
1233		1495
1234	This is now awfully much, so queuing lots of requests is not usually a	1496	This is not awfully much, so queuing lots of requests is not usually a
1235	problem.	1497	problem.
1236		1498
1237	Per-thread usage:	1499	Per-thread usage:
1238		1500
1239	In the execution phase, some aio requests require more memory for	1501	In the execution phase, some aio requests require more memory for
…		…
1244		1506
1245	Known bugs will be fixed in the next release.	1507	Known bugs will be fixed in the next release.
1246		1508
1247	=head1 SEE ALSO	1509	=head1 SEE ALSO
1248		1510
1249	L<Coro::AIO>.	1511	L<AnyEvent::AIO> for easy integration into event loops, L<Coro::AIO> for a
		1512	more natural syntax.
1250		1513
1251	=head1 AUTHOR	1514	=head1 AUTHOR
1252		1515
1253	Marc Lehmann <schmorp@schmorp.de>	1516	Marc Lehmann <schmorp@schmorp.de>
1254	http://home.schmorp.de/	1517	http://home.schmorp.de/

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Comparing IO-AIO/AIO.pm (file contents): Revision 1.105 by root, Sun Mar 25 00:20:27 2007 UTC vs. Revision 1.170 by root, Sat Jan 2 14:11:32 2010 UTC

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Comparing IO-AIO/AIO.pm (file contents):
Revision 1.105 by root, Sun Mar 25 00:20:27 2007 UTC vs.
Revision 1.170 by root, Sat Jan 2 14:11:32 2010 UTC