[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 1.165 by root, Tue Aug 18 04:05:00 2009 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 = '3.3';
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
201	our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice aio_block));	206	our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice));
202	our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush	207	our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush
203	min_parallel max_parallel max_idle	208	min_parallel max_parallel max_idle
204	nreqs nready npending nthreads	209	nreqs nready npending nthreads
205	max_poll_time max_poll_reqs);	210	max_poll_time max_poll_reqs
		211	sendfile fadvise);
		212
		213	push @AIO_REQ, qw(aio_busy); # not exported
206		214
207	@IO::AIO::GRP::ISA = 'IO::AIO::REQ';	215	@IO::AIO::GRP::ISA = 'IO::AIO::REQ';
208		216
209	require XSLoader;	217	require XSLoader;
210	XSLoader::load ("IO::AIO", $VERSION);	218	XSLoader::load ("IO::AIO", $VERSION);
…		…
217	All the C<aio_*> calls are more or less thin wrappers around the syscall	225	All the C<aio_*> calls are more or less thin wrappers around the syscall
218	with the same name (sans C<aio_>). The arguments are similar or identical,	226	with the same name (sans C<aio_>). The arguments are similar or identical,
219	and they all accept an additional (and optional) C<$callback> argument	227	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	228	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	229	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	230	perl, which usually delivers "false") as its sole argument after the given
223	syscall has been executed asynchronously.	231	syscall has been executed asynchronously.
224		232
225	All functions expecting a filehandle keep a copy of the filehandle	233	All functions expecting a filehandle keep a copy of the filehandle
226	internally until the request has finished.	234	internally until the request has finished.
227		235
…		…
241	your pathnames to the locale (or other) encoding in effect in the user	249	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)	250	environment, d) use Glib::filename_from_unicode on unicode filenames or e)
243	use something else to ensure your scalar has the correct contents.	251	use something else to ensure your scalar has the correct contents.
244		252
245	This works, btw. independent of the internal UTF-8 bit, which IO::AIO	253	This works, btw. independent of the internal UTF-8 bit, which IO::AIO
246	handles correctly wether it is set or not.	254	handles correctly whether it is set or not.
247		255
248	=over 4	256	=over 4
249		257
250	=item $prev_pri = aioreq_pri [$pri]	258	=item $prev_pri = aioreq_pri [$pri]
251		259
…		…
271	aio_read $_[0], ..., sub {	279	aio_read $_[0], ..., sub {
272	...	280	...
273	};	281	};
274	};	282	};
275		283
		284
276	=item aioreq_nice $pri_adjust	285	=item aioreq_nice $pri_adjust
277		286
278	Similar to C<aioreq_pri>, but subtracts the given value from the current	287	Similar to C<aioreq_pri>, but subtracts the given value from the current
279	priority, so the effect is cumulative.	288	priority, so the effect is cumulative.
		289
280		290
281	=item aio_open $pathname, $flags, $mode, $callback->($fh)	291	=item aio_open $pathname, $flags, $mode, $callback->($fh)
282		292
283	Asynchronously open or create a file and call the callback with a newly	293	Asynchronously open or create a file and call the callback with a newly
284	created filehandle for the file.	294	created filehandle for the file.
…		…
305	} else {	315	} else {
306	die "open failed: $!\n";	316	die "open failed: $!\n";
307	}	317	}
308	};	318	};
309		319
		320
310	=item aio_close $fh, $callback->($status)	321	=item aio_close $fh, $callback->($status)
311		322
312	Asynchronously close a file and call the callback with the result	323	Asynchronously close a file and call the callback with the result
313	code. I<WARNING:> although accepted, you should not pass in a perl	324	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		325
318	This is supposed to be a bug in the API, so that might change. It's	326	Unfortunately, you can't do this to perl. Perl I<insists> very strongly on
319	therefore best to avoid this function.	327	closing the file descriptor associated with the filehandle itself.
		328
		329	Therefore, C<aio_close> will not close the filehandle - instead it will
		330	use dup2 to overwrite the file descriptor with the write-end of a pipe
		331	(the pipe fd will be created on demand and will be cached).
		332
		333	Or in other words: the file descriptor will be closed, but it will not be
		334	free for reuse until the perl filehandle is closed.
		335
		336	=cut
320		337
321	=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)	338	=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
322		339
323	=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)	340	=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
324		341
325	Reads or writes C<length> bytes from the specified C<fh> and C<offset>	342	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	343	C<$offset> into the scalar given by C<$data> and offset C<$dataoffset>
327	callback without the actual number of bytes read (or -1 on error, just	344	and calls the callback without the actual number of bytes read (or -1 on
328	like the syscall).	345	error, just like the syscall).
		346
		347	C<aio_read> will, like C<sysread>, shrink or grow the C<$data> scalar to
		348	offset plus the actual number of bytes read.
		349
		350	If C<$offset> is undefined, then the current file descriptor offset will
		351	be used (and updated), otherwise the file descriptor offset will not be
		352	changed by these calls.
		353
		354	If C<$length> is undefined in C<aio_write>, use the remaining length of
		355	C<$data>.
		356
		357	If C<$dataoffset> is less than zero, it will be counted from the end of
		358	C<$data>.
329		359
330	The C<$data> scalar I<MUST NOT> be modified in any way while the request	360	The C<$data> scalar I<MUST NOT> be modified in any way while the request
331	is outstanding. Modifying it can result in segfaults or WW3 (if the	361	is outstanding. Modifying it can result in segfaults or World War III (if
332	necessary/optional hardware is installed).	362	the necessary/optional hardware is installed).
333		363
334	Example: Read 15 bytes at offset 7 into scalar C<$buffer>, starting at	364	Example: Read 15 bytes at offset 7 into scalar C<$buffer>, starting at
335	offset C<0> within the scalar:	365	offset C<0> within the scalar:
336		366
337	aio_read $fh, 7, 15, $buffer, 0, sub {	367	aio_read $fh, 7, 15, $buffer, 0, sub {
338	$_[0] > 0 or die "read error: $!";	368	$_[0] > 0 or die "read error: $!";
339	print "read $_[0] bytes: <$buffer>\n";	369	print "read $_[0] bytes: <$buffer>\n";
340	};	370	};
		371
341		372
342	=item aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval)	373	=item aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval)
343		374
344	Tries to copy C<$length> bytes from C<$in_fh> to C<$out_fh>. It starts	375	Tries to copy C<$length> bytes from C<$in_fh> to C<$out_fh>. It starts
345	reading at byte offset C<$in_offset>, and starts writing at the current	376	reading at byte offset C<$in_offset>, and starts writing at the current
…		…
359	C<$in_fh> than are written, and there is no way to find out how many	390	C<$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	391	bytes have been read from C<aio_sendfile> alone, as C<aio_sendfile> only
361	provides the number of bytes written to C<$out_fh>. Only if the result	392	provides the number of bytes written to C<$out_fh>. Only if the result
362	value equals C<$length> one can assume that C<$length> bytes have been	393	value equals C<$length> one can assume that C<$length> bytes have been
363	read.	394	read.
		395
364		396
365	=item aio_readahead $fh,$offset,$length, $callback->($retval)	397	=item aio_readahead $fh,$offset,$length, $callback->($retval)
366		398
367	C<aio_readahead> populates the page cache with data from a file so that	399	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<$offset>	400	subsequent reads from that file will not block on disk I/O. The C<$offset>
…		…
374	file. The current file offset of the file is left unchanged.	406	file. The current file offset of the file is left unchanged.
375		407
376	If that syscall doesn't exist (likely if your OS isn't Linux) it will be	408	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.	409	emulated by simply reading the data, which would have a similar effect.
378		410
		411
379	=item aio_stat $fh_or_path, $callback->($status)	412	=item aio_stat $fh_or_path, $callback->($status)
380		413
381	=item aio_lstat $fh, $callback->($status)	414	=item aio_lstat $fh, $callback->($status)
382		415
383	Works like perl's C<stat> or C<lstat> in void context. The callback will	416	Works like perl's C<stat> or C<lstat> in void context. The callback will
…		…
396	aio_stat "/etc/passwd", sub {	429	aio_stat "/etc/passwd", sub {
397	$_[0] and die "stat failed: $!";	430	$_[0] and die "stat failed: $!";
398	print "size is ", -s _, "\n";	431	print "size is ", -s _, "\n";
399	};	432	};
400		433
		434
		435	=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
		436
		437	Works like perl's C<utime> function (including the special case of $atime
		438	and $mtime being undef). Fractional times are supported if the underlying
		439	syscalls support them.
		440
		441	When called with a pathname, uses utimes(2) if available, otherwise
		442	utime(2). If called on a file descriptor, uses futimes(2) if available,
		443	otherwise returns ENOSYS, so this is not portable.
		444
		445	Examples:
		446
		447	# set atime and mtime to current time (basically touch(1)):
		448	aio_utime "path", undef, undef;
		449	# set atime to current time and mtime to beginning of the epoch:
		450	aio_utime "path", time, undef; # undef==0
		451
		452
		453	=item aio_chown $fh_or_path, $uid, $gid, $callback->($status)
		454
		455	Works like perl's C<chown> function, except that C<undef> for either $uid
		456	or $gid is being interpreted as "do not change" (but -1 can also be used).
		457
		458	Examples:
		459
		460	# same as "chown root path" in the shell:
		461	aio_chown "path", 0, -1;
		462	# same as above:
		463	aio_chown "path", 0, undef;
		464
		465
		466	=item aio_truncate $fh_or_path, $offset, $callback->($status)
		467
		468	Works like truncate(2) or ftruncate(2).
		469
		470
		471	=item aio_chmod $fh_or_path, $mode, $callback->($status)
		472
		473	Works like perl's C<chmod> function.
		474
		475
401	=item aio_unlink $pathname, $callback->($status)	476	=item aio_unlink $pathname, $callback->($status)
402		477
403	Asynchronously unlink (delete) a file and call the callback with the	478	Asynchronously unlink (delete) a file and call the callback with the
404	result code.	479	result code.
405		480
		481
406	=item aio_mknod $path, $mode, $dev, $callback->($status)	482	=item aio_mknod $path, $mode, $dev, $callback->($status)
407		483
408	[EXPERIMENTAL]	484	[EXPERIMENTAL]
409		485
410	Asynchronously create a device node (or fifo). See mknod(2).	486	Asynchronously create a device node (or fifo). See mknod(2).
411		487
412	The only (POSIX-) portable way of calling this function is:	488	The only (POSIX-) portable way of calling this function is:
413		489
414	aio_mknod $path, IO::AIO::S_IFIFO \| $mode, 0, sub { ...	490	aio_mknod $path, IO::AIO::S_IFIFO \| $mode, 0, sub { ...
		491
415		492
416	=item aio_link $srcpath, $dstpath, $callback->($status)	493	=item aio_link $srcpath, $dstpath, $callback->($status)
417		494
418	Asynchronously create a new link to the existing object at C<$srcpath> at	495	Asynchronously create a new link to the existing object at C<$srcpath> at
419	the path C<$dstpath> and call the callback with the result code.	496	the path C<$dstpath> and call the callback with the result code.
420		497
		498
421	=item aio_symlink $srcpath, $dstpath, $callback->($status)	499	=item aio_symlink $srcpath, $dstpath, $callback->($status)
422		500
423	Asynchronously create a new symbolic link to the existing object at C<$srcpath> at	501	Asynchronously create a new symbolic link to the existing object at C<$srcpath> at
424	the path C<$dstpath> and call the callback with the result code.	502	the path C<$dstpath> and call the callback with the result code.
		503
425		504
426	=item aio_readlink $path, $callback->($link)	505	=item aio_readlink $path, $callback->($link)
427		506
428	Asynchronously read the symlink specified by C<$path> and pass it to	507	Asynchronously read the symlink specified by C<$path> and pass it to
429	the callback. If an error occurs, nothing or undef gets passed to the	508	the callback. If an error occurs, nothing or undef gets passed to the
430	callback.	509	callback.
431		510
		511
432	=item aio_rename $srcpath, $dstpath, $callback->($status)	512	=item aio_rename $srcpath, $dstpath, $callback->($status)
433		513
434	Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as	514	Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as
435	rename(2) and call the callback with the result code.	515	rename(2) and call the callback with the result code.
		516
436		517
437	=item aio_mkdir $pathname, $mode, $callback->($status)	518	=item aio_mkdir $pathname, $mode, $callback->($status)
438		519
439	Asynchronously mkdir (create) a directory and call the callback with	520	Asynchronously mkdir (create) a directory and call the callback with
440	the result code. C<$mode> will be modified by the umask at the time the	521	the result code. C<$mode> will be modified by the umask at the time the
441	request is executed, so do not change your umask.	522	request is executed, so do not change your umask.
442		523
		524
443	=item aio_rmdir $pathname, $callback->($status)	525	=item aio_rmdir $pathname, $callback->($status)
444		526
445	Asynchronously rmdir (delete) a directory and call the callback with the	527	Asynchronously rmdir (delete) a directory and call the callback with the
446	result code.	528	result code.
		529
447		530
448	=item aio_readdir $pathname, $callback->($entries)	531	=item aio_readdir $pathname, $callback->($entries)
449		532
450	Unlike the POSIX call of the same name, C<aio_readdir> reads an entire	533	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	534	directory (i.e. opendir + readdir + closedir). The entries will not be
452	sorted, and will B<NOT> include the C<.> and C<..> entries.	535	sorted, and will B<NOT> include the C<.> and C<..> entries.
453		536
454	The callback a single argument which is either C<undef> or an array-ref	537	The callback is passed a single argument which is either C<undef> or an
455	with the filenames.	538	array-ref with the filenames.
		539
		540
		541	=item aio_readdirx $pathname, $flags, $callback->($entries, $flags)
		542
		543	Quite similar to C<aio_readdir>, but the C<$flags> argument allows to tune
		544	behaviour and output format. In case of an error, C<$entries> will be
		545	C<undef>.
		546
		547	The flags are a combination of the following constants, ORed together (the
		548	flags will also be passed to the callback, possibly modified):
		549
		550	=over 4
		551
		552	=item IO::AIO::READDIR_DENTS
		553
		554	When this flag is off, then the callback gets an arrayref with of names
		555	only (as with C<aio_readdir>), otherwise it gets an arrayref with
		556	C<[$name, $type, $inode]> arrayrefs, each describing a single directory
		557	entry in more detail.
		558
		559	C<$name> is the name of the entry.
		560
		561	C<$type> is one of the C<IO::AIO::DT_xxx> constants:
		562
		563	C<IO::AIO::DT_UNKNOWN>, C<IO::AIO::DT_FIFO>, C<IO::AIO::DT_CHR>, C<IO::AIO::DT_DIR>,
		564	C<IO::AIO::DT_BLK>, C<IO::AIO::DT_REG>, C<IO::AIO::DT_LNK>, C<IO::AIO::DT_SOCK>,
		565	C<IO::AIO::DT_WHT>.
		566
		567	C<IO::AIO::DT_UNKNOWN> means just that: readdir does not know. If you need to
		568	know, you have to run stat yourself. Also, for speed reasons, the C<$type>
		569	scalars are read-only: you can not modify them.
		570
		571	C<$inode> is the inode number (which might not be exact on systems with 64
		572	bit inode numbers and 32 bit perls). This field has unspecified content on
		573	systems that do not deliver the inode information.
		574
		575	=item IO::AIO::READDIR_DIRS_FIRST
		576
		577	When this flag is set, then the names will be returned in an order where
		578	likely directories come first. This is useful when you need to quickly
		579	find directories, or you want to find all directories while avoiding to
		580	stat() each entry.
		581
		582	If the system returns type information in readdir, then this is used
		583	to find directories directly. Otherwise, likely directories are files
		584	beginning with ".", or otherwise files with no dots, of which files with
		585	short names are tried first.
		586
		587	=item IO::AIO::READDIR_STAT_ORDER
		588
		589	When this flag is set, then the names will be returned in an order
		590	suitable for stat()'ing each one. That is, when you plan to stat()
		591	all files in the given directory, then the returned order will likely
		592	be fastest.
		593
		594	If both this flag and C<IO::AIO::READDIR_DIRS_FIRST> are specified, then
		595	the likely dirs come first, resulting in a less optimal stat order.
		596
		597	=item IO::AIO::READDIR_FOUND_UNKNOWN
		598
		599	This flag should not be set when calling C<aio_readdirx>. Instead, it
		600	is being set by C<aio_readdirx>, when any of the C<$type>'s found were
		601	C<IO::AIO::DT_UNKNOWN>. The absense of this flag therefore indicates that all
		602	C<$type>'s are known, which can be used to speed up some algorithms.
		603
		604	=back
		605
456		606
457	=item aio_load $path, $data, $callback->($status)	607	=item aio_load $path, $data, $callback->($status)
458		608
459	This is a composite request that tries to fully load the given file into	609	This is a composite request that tries to fully load the given file into
460	memory. Status is the same as with aio_read.	610	memory. Status is the same as with aio_read.
461		611
462	=cut	612	=cut
463		613
464	sub aio_load($$;$) {	614	sub aio_load($$;$) {
465	aio_block {
466	my ($path, undef, $cb) = @_;	615	my ($path, undef, $cb) = @_;
467	my $data = \$_[1];	616	my $data = \$_[1];
468		617
469	my $pri = aioreq_pri;	618	my $pri = aioreq_pri;
470	my $grp = aio_group $cb;	619	my $grp = aio_group $cb;
		620
		621	aioreq_pri $pri;
		622	add $grp aio_open $path, O_RDONLY, 0, sub {
		623	my $fh = shift
		624	or return $grp->result (-1);
471		625
472	aioreq_pri $pri;	626	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), $$data, 0, sub {	627	add $grp aio_read $fh, 0, (-s $fh), $$data, 0, sub {
479	$grp->result ($_[0]);	628	$grp->result ($_[0]);
480	};
481	};	629	};
482
483	$grp
484	}	630	};
		631
		632	$grp
485	}	633	}
486		634
487	=item aio_copy $srcpath, $dstpath, $callback->($status)	635	=item aio_copy $srcpath, $dstpath, $callback->($status)
488		636
489	Try to copy the I<file> (directories not supported as either source or	637	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	638	destination) from C<$srcpath> to C<$dstpath> and call the callback with
491	the C<0> (error) or C<-1> ok.	639	a status of C<0> (ok) or C<-1> (error, see C<$!>).
492		640
493	This is a composite request that it creates the destination file with	641	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	642	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	643	C<aio_sendfile>, followed by restoring atime, mtime, access mode and
496	uid/gid, in that order.	644	uid/gid, in that order.
497		645
498	If an error occurs, the partial destination file will be unlinked, if	646	If an error occurs, the partial destination file will be unlinked, if
…		…
500	errors are being ignored.	648	errors are being ignored.
501		649
502	=cut	650	=cut
503		651
504	sub aio_copy($$;$) {	652	sub aio_copy($$;$) {
505	aio_block {
506	my ($src, $dst, $cb) = @_;	653	my ($src, $dst, $cb) = @_;
507		654
508	my $pri = aioreq_pri;	655	my $pri = aioreq_pri;
509	my $grp = aio_group $cb;	656	my $grp = aio_group $cb;
510		657
511	aioreq_pri $pri;	658	aioreq_pri $pri;
512	add $grp aio_open $src, O_RDONLY, 0, sub {	659	add $grp aio_open $src, O_RDONLY, 0, sub {
513	if (my $src_fh = $_[0]) {	660	if (my $src_fh = $_[0]) {
514	my @stat = stat $src_fh;	661	my @stat = stat $src_fh; # hmm, might bock over nfs?
515		662
516	aioreq_pri $pri;	663	aioreq_pri $pri;
517	add $grp aio_open $dst, O_CREAT \| O_WRONLY \| O_TRUNC, 0200, sub {	664	add $grp aio_open $dst, O_CREAT \| O_WRONLY \| O_TRUNC, 0200, sub {
518	if (my $dst_fh = $_[0]) {	665	if (my $dst_fh = $_[0]) {
519	aioreq_pri $pri;	666	aioreq_pri $pri;
520	add $grp aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub {	667	add $grp aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub {
521	if ($_[0] == $stat[7]) {	668	if ($_[0] == $stat[7]) {
522	$grp->result (0);	669	$grp->result (0);
523	close $src_fh;	670	close $src_fh;
524		671
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 {	672	my $ch = sub {
531	$grp->result (-1);
532	close $src_fh;
533	close $dst_fh;
534
535	aioreq $pri;	673	aioreq_pri $pri;
		674	add $grp aio_chmod $dst_fh, $stat[2] & 07777, sub {
		675	aioreq_pri $pri;
		676	add $grp aio_chown $dst_fh, $stat[4], $stat[5], sub {
		677	aioreq_pri $pri;
536	add $grp aio_unlink $dst;	678	add $grp aio_close $dst_fh;
		679	}
		680	};
537	}	681	};
		682
		683	aioreq_pri $pri;
		684	add $grp aio_utime $dst_fh, $stat[8], $stat[9], sub {
		685	if ($_[0] < 0 && $! == ENOSYS) {
		686	aioreq_pri $pri;
		687	add $grp aio_utime $dst, $stat[8], $stat[9], $ch;
		688	} else {
		689	$ch->();
		690	}
		691	};
		692	} else {
		693	$grp->result (-1);
		694	close $src_fh;
		695	close $dst_fh;
		696
		697	aioreq $pri;
		698	add $grp aio_unlink $dst;
538	};	699	}
539	} else {
540	$grp->result (-1);
541	}	700	};
		701	} else {
		702	$grp->result (-1);
542	},	703	}
543
544	} else {
545	$grp->result (-1);
546	}	704	},
		705
		706	} else {
		707	$grp->result (-1);
547	};	708	}
548
549	$grp
550	}	709	};
		710
		711	$grp
551	}	712	}
552		713
553	=item aio_move $srcpath, $dstpath, $callback->($status)	714	=item aio_move $srcpath, $dstpath, $callback->($status)
554		715
555	Try to move the I<file> (directories not supported as either source or	716	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	717	destination) from C<$srcpath> to C<$dstpath> and call the callback with
557	the C<0> (error) or C<-1> ok.	718	a status of C<0> (ok) or C<-1> (error, see C<$!>).
558		719
559	This is a composite request that tries to rename(2) the file first. If	720	This is a composite request that tries to rename(2) the file first; if
560	rename files with C<EXDEV>, it copies the file with C<aio_copy> and, if	721	rename fails with C<EXDEV>, it copies the file with C<aio_copy> and, if
561	that is successful, unlinking the C<$srcpath>.	722	that is successful, unlinks the C<$srcpath>.
562		723
563	=cut	724	=cut
564		725
565	sub aio_move($$;$) {	726	sub aio_move($$;$) {
566	aio_block {
567	my ($src, $dst, $cb) = @_;	727	my ($src, $dst, $cb) = @_;
568		728
569	my $pri = aioreq_pri;	729	my $pri = aioreq_pri;
570	my $grp = aio_group $cb;	730	my $grp = aio_group $cb;
571		731
572	aioreq_pri $pri;	732	aioreq_pri $pri;
573	add $grp aio_rename $src, $dst, sub {	733	add $grp aio_rename $src, $dst, sub {
574	if ($_[0] && $! == EXDEV) {	734	if ($_[0] && $! == EXDEV) {
575	aioreq_pri $pri;	735	aioreq_pri $pri;
576	add $grp aio_copy $src, $dst, sub {	736	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]);	737	$grp->result ($_[0]);
		738
		739	if (!$_[0]) {
		740	aioreq_pri $pri;
		741	add $grp aio_unlink $src;
		742	}
586	}	743	};
		744	} else {
		745	$grp->result ($_[0]);
587	};	746	}
588
589	$grp
590	}	747	};
		748
		749	$grp
591	}	750	}
592		751
593	=item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs)	752	=item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs)
594		753
595	Scans a directory (similar to C<aio_readdir>) but additionally tries to	754	Scans a directory (similar to C<aio_readdir>) but additionally tries to
…		…
615		774
616	Implementation notes.	775	Implementation notes.
617		776
618	The C<aio_readdir> cannot be avoided, but C<stat()>'ing every entry can.	777	The C<aio_readdir> cannot be avoided, but C<stat()>'ing every entry can.
619		778
		779	If readdir returns file type information, then this is used directly to
		780	find directories.
		781
620	After reading the directory, the modification time, size etc. of the	782	Otherwise, after reading the directory, the modification time, size etc.
621	directory before and after the readdir is checked, and if they match (and	783	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	784	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	785	how many entries are directories (if >= 2). Otherwise, no knowledge of the
624	of subdirectories will be assumed.	786	number of subdirectories will be assumed.
625		787
626	Then entries will be sorted into likely directories (everything without	788	Then entries will be sorted into likely directories a non-initial dot
627	a non-initial dot currently) and likely non-directories (everything	789	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,	790	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	791	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	792	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	793	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	794	filesystems might detect the type of the entry without reading the inode
633	data (e.g. ext2fs filetype feature).	795	data (e.g. ext2fs filetype feature), even on systems that cannot return
		796	the filetype information on readdir.
634		797
635	If the known number of directories (link count - 2) has been reached, the	798	If the known number of directories (link count - 2) has been reached, the
636	rest of the entries is assumed to be non-directories.	799	rest of the entries is assumed to be non-directories.
637		800
638	This only works with certainty on POSIX (= UNIX) filesystems, which	801	This only works with certainty on POSIX (= UNIX) filesystems, which
…		…
643	directory counting heuristic.	806	directory counting heuristic.
644		807
645	=cut	808	=cut
646		809
647	sub aio_scandir($$;$) {	810	sub aio_scandir($$;$) {
648	aio_block {
649	my ($path, $maxreq, $cb) = @_;	811	my ($path, $maxreq, $cb) = @_;
650		812
651	my $pri = aioreq_pri;	813	my $pri = aioreq_pri;
652		814
653	my $grp = aio_group $cb;	815	my $grp = aio_group $cb;
654		816
655	$maxreq = 4 if $maxreq <= 0;	817	$maxreq = 4 if $maxreq <= 0;
656		818
657	# stat once	819	# stat once
		820	aioreq_pri $pri;
		821	add $grp aio_stat $path, sub {
		822	return $grp->result () if $_[0];
		823	my $now = time;
		824	my $hash1 = join ":", (stat _)[0,1,3,7,9];
		825
		826	# read the directory entries
658	aioreq_pri $pri;	827	aioreq_pri $pri;
659	add $grp aio_stat $path, sub {	828	add $grp aio_readdirx $path, READDIR_DIRS_FIRST, sub {
		829	my $entries = shift
660	return $grp->result () if $_[0];	830	or return $grp->result ();
661	my $now = time;
662	my $hash1 = join ":", (stat _)[0,1,3,7,9];
663		831
664	# read the directory entries	832	# stat the dir another time
665	aioreq_pri $pri;	833	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 {	834	add $grp aio_stat $path, sub {
673	my $hash2 = join ":", (stat _)[0,1,3,7,9];	835	my $hash2 = join ":", (stat _)[0,1,3,7,9];
674		836
675	my $ndirs;	837	my $ndirs;
676		838
677	# take the slow route if anything looks fishy	839	# take the slow route if anything looks fishy
678	if ($hash1 ne $hash2 or (stat _)[9] == $now) {	840	if ($hash1 ne $hash2 or (stat _)[9] == $now) {
679	$ndirs = -1;	841	$ndirs = -1;
680	} else {	842	} else {
681	# if nlink == 2, we are finished	843	# if nlink == 2, we are finished
682	# on non-posix-fs's, we rely on nlink < 2	844	# for non-posix-fs's, we rely on nlink < 2
683	$ndirs = (stat _)[3] - 2	845	$ndirs = (stat _)[3] - 2
684	or return $grp->result ([], $entries);	846	or return $grp->result ([], $entries);
685	}	847	}
686		848
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);	849	my (@dirs, @nondirs);
695		850
696	my $statgrp = add $grp aio_group sub {	851	my $statgrp = add $grp aio_group sub {
697	$grp->result (\@dirs, \@nondirs);	852	$grp->result (\@dirs, \@nondirs);
698	};	853	};
699		854
700	limit $statgrp $maxreq;	855	limit $statgrp $maxreq;
701	feed $statgrp sub {	856	feed $statgrp sub {
702	return unless @$entries;	857	return unless @$entries;
703	my $entry = pop @$entries;	858	my $entry = shift @$entries;
704		859
705	aioreq_pri $pri;	860	aioreq_pri $pri;
706	add $statgrp aio_stat "$path/$entry/.", sub {	861	add $statgrp aio_stat "$path/$entry/.", sub {
707	if ($_[0] < 0) {	862	if ($_[0] < 0) {
708	push @nondirs, $entry;	863	push @nondirs, $entry;
709	} else {	864	} else {
710	# need to check for real directory	865	# need to check for real directory
711	aioreq_pri $pri;	866	aioreq_pri $pri;
712	add $statgrp aio_lstat "$path/$entry", sub {	867	add $statgrp aio_lstat "$path/$entry", sub {
713	if (-d _) {	868	if (-d _) {
714	push @dirs, $entry;	869	push @dirs, $entry;
715		870
716	unless (--$ndirs) {	871	unless (--$ndirs) {
717	push @nondirs, @$entries;	872	push @nondirs, @$entries;
718	feed $statgrp;	873	feed $statgrp;
719	}
720	} else {
721	push @nondirs, $entry;
722	}	874	}
		875	} else {
		876	push @nondirs, $entry;
723	}	877	}
724	}	878	}
725	};	879	}
726	};	880	};
727	};	881	};
728	};	882	};
729	};	883	};
730
731	$grp
732	}	884	};
		885
		886	$grp
733	}	887	}
734		888
735	=item aio_rmtree $path, $callback->($status)	889	=item aio_rmtree $path, $callback->($status)
736		890
737	Delete a directory tree starting (and including) C<$path>, return the	891	Delete a directory tree starting (and including) C<$path>, return the
…		…
741		895
742	=cut	896	=cut
743		897
744	sub aio_rmtree;	898	sub aio_rmtree;
745	sub aio_rmtree($;$) {	899	sub aio_rmtree($;$) {
746	aio_block {
747	my ($path, $cb) = @_;	900	my ($path, $cb) = @_;
748		901
749	my $pri = aioreq_pri;	902	my $pri = aioreq_pri;
750	my $grp = aio_group $cb;	903	my $grp = aio_group $cb;
751		904
752	aioreq_pri $pri;	905	aioreq_pri $pri;
753	add $grp aio_scandir $path, 0, sub {	906	add $grp aio_scandir $path, 0, sub {
754	my ($dirs, $nondirs) = @_;	907	my ($dirs, $nondirs) = @_;
755		908
756	my $dirgrp = aio_group sub {	909	my $dirgrp = aio_group sub {
757	add $grp aio_rmdir $path, sub {	910	add $grp aio_rmdir $path, sub {
758	$grp->result ($_[0]);	911	$grp->result ($_[0]);
759	};
760	};	912	};
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	};	913	};
767		914
768	$grp	915	(aioreq_pri $pri), add $dirgrp aio_rmtree "$path/$_" for @$dirs;
		916	(aioreq_pri $pri), add $dirgrp aio_unlink "$path/$_" for @$nondirs;
		917
		918	add $grp $dirgrp;
769	}	919	};
		920
		921	$grp
770	}	922	}
		923
		924	=item aio_sync $callback->($status)
		925
		926	Asynchronously call sync and call the callback when finished.
771		927
772	=item aio_fsync $fh, $callback->($status)	928	=item aio_fsync $fh, $callback->($status)
773		929
774	Asynchronously call fsync on the given filehandle and call the callback	930	Asynchronously call fsync on the given filehandle and call the callback
775	with the fsync result code.	931	with the fsync result code.
…		…
779	Asynchronously call fdatasync on the given filehandle and call the	935	Asynchronously call fdatasync on the given filehandle and call the
780	callback with the fdatasync result code.	936	callback with the fdatasync result code.
781		937
782	If this call isn't available because your OS lacks it or it couldn't be	938	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.	939	detected, it will be emulated by calling C<fsync> instead.
		940
		941	=item aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status)
		942
		943	Sync the data portion of the file specified by C<$offset> and C<$length>
		944	to disk (but NOT the metadata), by calling the Linux-specific
		945	sync_file_range call. If sync_file_range is not available or it returns
		946	ENOSYS, then fdatasync or fsync is being substituted.
		947
		948	C<$flags> can be a combination of C<IO::AIO::SYNC_FILE_RANGE_WAIT_BEFORE>,
		949	C<IO::AIO::SYNC_FILE_RANGE_WRITE> and
		950	C<IO::AIO::SYNC_FILE_RANGE_WAIT_AFTER>: refer to the sync_file_range
		951	manpage for details.
		952
		953	=item aio_pathsync $path, $callback->($status)
		954
		955	This request tries to open, fsync and close the given path. This is a
		956	composite request intended to sync directories after directory operations
		957	(E.g. rename). This might not work on all operating systems or have any
		958	specific effect, but usually it makes sure that directory changes get
		959	written to disc. It works for anything that can be opened for read-only,
		960	not just directories.
		961
		962	Future versions of this function might fall back to other methods when
		963	C<fsync> on the directory fails (such as calling C<sync>).
		964
		965	Passes C<0> when everything went ok, and C<-1> on error.
		966
		967	=cut
		968
		969	sub aio_pathsync($;$) {
		970	my ($path, $cb) = @_;
		971
		972	my $pri = aioreq_pri;
		973	my $grp = aio_group $cb;
		974
		975	aioreq_pri $pri;
		976	add $grp aio_open $path, O_RDONLY, 0, sub {
		977	my ($fh) = @_;
		978	if ($fh) {
		979	aioreq_pri $pri;
		980	add $grp aio_fsync $fh, sub {
		981	$grp->result ($_[0]);
		982
		983	aioreq_pri $pri;
		984	add $grp aio_close $fh;
		985	};
		986	} else {
		987	$grp->result (-1);
		988	}
		989	};
		990
		991	$grp
		992	}
784		993
785	=item aio_group $callback->(...)	994	=item aio_group $callback->(...)
786		995
787	This is a very special aio request: Instead of doing something, it is a	996	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	997	container for other aio requests, which is useful if you want to bundle
…		…
838	=item cancel $req	1047	=item cancel $req
839		1048
840	Cancels the request, if possible. Has the effect of skipping execution	1049	Cancels the request, if possible. Has the effect of skipping execution
841	when entering the B<execute> state and skipping calling the callback when	1050	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	1051	entering the the B<result> state, but will leave the request otherwise
843	untouched. That means that requests that currently execute will not be	1052	untouched (with the exception of readdir). That means that requests that
844	stopped and resources held by the request will not be freed prematurely.	1053	currently execute will not be stopped and resources held by the request
		1054	will not be freed prematurely.
845		1055
846	=item cb $req $callback->(...)	1056	=item cb $req $callback->(...)
847		1057
848	Replace (or simply set) the callback registered to the request.	1058	Replace (or simply set) the callback registered to the request.
849		1059
…		…
900	Their lifetime, simplified, looks like this: when they are empty, they	1110	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	1111	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	1112	C<done> state, they will also finish. Otherwise they will continue to
903	exist.	1113	exist.
904		1114
905	That means after creating a group you have some time to add requests. And	1115	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	1116	(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	1117	the C<poll_cb>). And in the callbacks of those requests, you can add
908	itself finish.	1118	further requests to the group. And only when all those requests have
		1119	finished will the the group itself finish.
909		1120
910	=over 4	1121	=over 4
911		1122
912	=item add $grp ...	1123	=item add $grp ...
913		1124
…		…
925	itself. Useful when you queued a lot of events but got a result early.	1136	itself. Useful when you queued a lot of events but got a result early.
926		1137
927	=item $grp->result (...)	1138	=item $grp->result (...)
928		1139
929	Set the result value(s) that will be passed to the group callback when all	1140	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	1141	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,	1142	of errno (just like calling C<errno> without an error number). By default,
932	no argument will be passed and errno is zero.	1143	no argument will be passed and errno is zero.
933		1144
934	=item $grp->errno ([$errno])	1145	=item $grp->errno ([$errno])
935		1146
…		…
946	=item feed $grp $callback->($grp)	1157	=item feed $grp $callback->($grp)
947		1158
948	Sets a feeder/generator on this group: every group can have an attached	1159	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,	1160	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,	1161	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	1162	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>	1163	C<aio_scandir> might generate hundreds of thousands C<aio_stat> requests,
953	requests, delaying any later requests for a long time.	1164	delaying any later requests for a long time.
954		1165
955	To avoid this, and allow incremental generation of requests, you can	1166	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	1167	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>,	1168	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	1169	below) requests active in the group itself and is expected to queue more
…		…
962	not impose any limits).	1173	not impose any limits).
963		1174
964	If the feed does not queue more requests when called, it will be	1175	If the feed does not queue more requests when called, it will be
965	automatically removed from the group.	1176	automatically removed from the group.
966		1177
967	If the feed limit is C<0>, it will be set to C<2> automatically.	1178	If the feed limit is C<0> when this method is called, it will be set to
		1179	C<2> automatically.
968		1180
969	Example:	1181	Example:
970		1182
971	# stat all files in @files, but only ever use four aio requests concurrently:	1183	# stat all files in @files, but only ever use four aio requests concurrently:
972		1184
…		…
984	Sets the feeder limit for the group: The feeder will be called whenever	1196	Sets the feeder limit for the group: The feeder will be called whenever
985	the group contains less than this many requests.	1197	the group contains less than this many requests.
986		1198
987	Setting the limit to C<0> will pause the feeding process.	1199	Setting the limit to C<0> will pause the feeding process.
988		1200
		1201	The default value for the limit is C<0>, but note that setting a feeder
		1202	automatically bumps it up to C<2>.
		1203
989	=back	1204	=back
990		1205
991	=head2 SUPPORT FUNCTIONS	1206	=head2 SUPPORT FUNCTIONS
992		1207
993	=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION	1208	=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION
…		…
995	=over 4	1210	=over 4
996		1211
997	=item $fileno = IO::AIO::poll_fileno	1212	=item $fileno = IO::AIO::poll_fileno
998		1213
999	Return the I<request result pipe file descriptor>. This filehandle must be	1214	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	1215	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	1216	select and so on, see below or the SYNOPSIS). If the pipe becomes readable
1002	to call C<poll_cb> to check the results.	1217	you have to call C<poll_cb> to check the results.
1003		1218
1004	See C<poll_cb> for an example.	1219	See C<poll_cb> for an example.
1005		1220
1006	=item IO::AIO::poll_cb	1221	=item IO::AIO::poll_cb
1007		1222
1008	Process some outstanding events on the result pipe. You have to call this	1223	Process some outstanding events on the result pipe. You have to call this
1009	regularly. Returns the number of events processed. Returns immediately	1224	regularly. Returns C<0> if all events could be processed, or C<-1> if it
		1225	returned earlier for whatever reason. Returns immediately when no events
1010	when no events are outstanding. The amount of events processed depends on	1226	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>.	1227	C<IO::AIO::max_poll_req> and C<IO::AIO::max_poll_time>.
1012		1228
1013	If not all requests were processed for whatever reason, the filehandle	1229	If not all requests were processed for whatever reason, the filehandle
1014	will still be ready when C<poll_cb> returns.	1230	will still be ready when C<poll_cb> returns, so normally you don't have to
		1231	do anything special to have it called later.
1015		1232
1016	Example: Install an Event watcher that automatically calls	1233	Example: Install an Event watcher that automatically calls
1017	IO::AIO::poll_cb with high priority:	1234	IO::AIO::poll_cb with high priority (more examples can be found in the
		1235	SYNOPSIS section, at the top of this document):
1018		1236
1019	Event->io (fd => IO::AIO::poll_fileno,	1237	Event->io (fd => IO::AIO::poll_fileno,
1020	poll => 'r', async => 1,	1238	poll => 'r', async => 1,
1021	cb => \&IO::AIO::poll_cb);	1239	cb => \&IO::AIO::poll_cb);
1022		1240
…		…
1133		1351
1134	The default is probably ok in most situations, especially if thread	1352	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	1353	creation is fast. If thread creation is very slow on your system you might
1136	want to use larger values.	1354	want to use larger values.
1137		1355
1138	=item $oldmaxreqs = IO::AIO::max_outstanding $maxreqs	1356	=item IO::AIO::max_outstanding $maxreqs
1139		1357
1140	This is a very bad function to use in interactive programs because it	1358	This is a very bad function to use in interactive programs because it
1141	blocks, and a bad way to reduce concurrency because it is inexact: Better	1359	blocks, and a bad way to reduce concurrency because it is inexact: Better
1142	use an C<aio_group> together with a feed callback.	1360	use an C<aio_group> together with a feed callback.
1143		1361
1144	Sets the maximum number of outstanding requests to C<$nreqs>. If you	1362	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	1363	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>)	1364	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.	1365	function will block until the limit is no longer exceeded.
1148		1366
1149	The default value is very large, so there is no practical limit on the	1367	The default value is very large, so there is no practical limit on the
1150	number of outstanding requests.	1368	number of outstanding requests.
1151		1369
1152	You can still queue as many requests as you want. Therefore,	1370	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	1371	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).	1372	as a stop gap to shield against fatal memory overflow (with large values).
1155		1373
1156	=back	1374	=back
1157		1375
1158	=head3 STATISTICAL INFORMATION	1376	=head3 STATISTICAL INFORMATION
…		…
1179	Returns the number of requests currently in the pending state (executed,	1397	Returns the number of requests currently in the pending state (executed,
1180	but not yet processed by poll_cb).	1398	but not yet processed by poll_cb).
1181		1399
1182	=back	1400	=back
1183		1401
		1402	=head3 MISCELLANEOUS FUNCTIONS
		1403
		1404	IO::AIO implements some functions that might be useful, but are not
		1405	asynchronous.
		1406
		1407	=over 4
		1408
		1409	=item IO::AIO::sendfile $ofh, $ifh, $offset, $count
		1410
		1411	Calls the C<eio_sendfile_sync> function, which is like C<aio_sendfile>,
		1412	but is blocking (this makes most sense if you know the input data is
		1413	likely cached already and the output filehandle is set to non-blocking
		1414	operations).
		1415
		1416	Returns the number of bytes copied, or C<-1> on error.
		1417
		1418	=item IO::AIO::fadvise $fh, $offset, $len, $advice
		1419
		1420	Simply calls the C<posix_fadvise> function (see it's
		1421	manpage for details). The following advice constants are
		1422	avaiable: C<IO::AIO::FADV_NORMAL>, C<IO::AIO::FADV_SEQUENTIAL>,
		1423	C<IO::AIO::FADV_RANDOM>, C<IO::AIO::FADV_NOREUSE>,
		1424	C<IO::AIO::FADV_WILLNEED>, C<IO::AIO::FADV_DONTNEED>.
		1425
		1426	On systems that do not implement C<posix_fadvise>, this function returns
		1427	ENOSYS, otherwise the return value of C<posix_fadvise>.
		1428
		1429	=back
		1430
1184	=cut	1431	=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		1432
1202	min_parallel 8;	1433	min_parallel 8;
1203		1434
1204	END { flush }	1435	END { flush }
1205		1436
…		…
1229	bytes of memory. In addition, stat requests need a stat buffer (possibly	1460	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	1461	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	1462	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.	1463	will consume memory till the request has entered the done state.
1233		1464
1234	This is now awfully much, so queuing lots of requests is not usually a	1465	This is not awfully much, so queuing lots of requests is not usually a
1235	problem.	1466	problem.
1236		1467
1237	Per-thread usage:	1468	Per-thread usage:
1238		1469
1239	In the execution phase, some aio requests require more memory for	1470	In the execution phase, some aio requests require more memory for
…		…
1244		1475
1245	Known bugs will be fixed in the next release.	1476	Known bugs will be fixed in the next release.
1246		1477
1247	=head1 SEE ALSO	1478	=head1 SEE ALSO
1248		1479
1249	L<Coro::AIO>.	1480	L<AnyEvent::AIO> for easy integration into event loops, L<Coro::AIO> for a
		1481	more natural syntax.
1250		1482
1251	=head1 AUTHOR	1483	=head1 AUTHOR
1252		1484
1253	Marc Lehmann <schmorp@schmorp.de>	1485	Marc Lehmann <schmorp@schmorp.de>
1254	http://home.schmorp.de/	1486	http://home.schmorp.de/

Diff Legend

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

Comparing IO-AIO/AIO.pm (file contents): Revision 1.105 by root, Sun Mar 25 00:20:27 2007 UTC vs. Revision 1.165 by root, Tue Aug 18 04:05:00 2009 UTC

Diff Legend

Comparing IO-AIO/AIO.pm (file contents):
Revision 1.105 by root, Sun Mar 25 00:20:27 2007 UTC vs.
Revision 1.165 by root, Tue Aug 18 04:05:00 2009 UTC