[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 1.169 by root, Sat Jan 2 13:02:20 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
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
…		…
349		380
350	This call tries to make use of a native C<sendfile> syscall to provide	381	This call tries to make use of a native C<sendfile> syscall to provide
351	zero-copy operation. For this to work, C<$out_fh> should refer to a	382	zero-copy operation. For this to work, C<$out_fh> should refer to a
352	socket, and C<$in_fh> should refer to mmap'able file.	383	socket, and C<$in_fh> should refer to mmap'able file.
353		384
354	If the native sendfile call fails or is not implemented, it will be	385	If the native sendfile call fails with C<ENOSYS>, C<ENOTSUP>,
		386	C<EOPNOTSUPP> or C<ENOTSOCK>, or is not implemented, it will be emulated,
355	emulated, so you can call C<aio_sendfile> on any type of filehandle	387	so you can call C<aio_sendfile> on any type of filehandle regardless of
356	regardless of the limitations of the operating system.	388	the limitations of the operating system.
357		389
358	Please note, however, that C<aio_sendfile> can read more bytes from	390	Please note, however, that C<aio_sendfile> can read more bytes from
359	C<$in_fh> than are written, and there is no way to find out how many	391	C<$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	392	bytes have been read from C<aio_sendfile> alone, as C<aio_sendfile> only
361	provides the number of bytes written to C<$out_fh>. Only if the result	393	provides the number of bytes written to C<$out_fh>. Only if the result
362	value equals C<$length> one can assume that C<$length> bytes have been	394	value equals C<$length> one can assume that C<$length> bytes have been
363	read.	395	read.
		396
364		397
365	=item aio_readahead $fh,$offset,$length, $callback->($retval)	398	=item aio_readahead $fh,$offset,$length, $callback->($retval)
366		399
367	C<aio_readahead> populates the page cache with data from a file so that	400	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<$offset>	401	subsequent reads from that file will not block on disk I/O. The C<$offset>
…		…
374	file. The current file offset of the file is left unchanged.	407	file. The current file offset of the file is left unchanged.
375		408
376	If that syscall doesn't exist (likely if your OS isn't Linux) it will be	409	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.	410	emulated by simply reading the data, which would have a similar effect.
378		411
		412
379	=item aio_stat $fh_or_path, $callback->($status)	413	=item aio_stat $fh_or_path, $callback->($status)
380		414
381	=item aio_lstat $fh, $callback->($status)	415	=item aio_lstat $fh, $callback->($status)
382		416
383	Works like perl's C<stat> or C<lstat> in void context. The callback will	417	Works like perl's C<stat> or C<lstat> in void context. The callback will
…		…
396	aio_stat "/etc/passwd", sub {	430	aio_stat "/etc/passwd", sub {
397	$_[0] and die "stat failed: $!";	431	$_[0] and die "stat failed: $!";
398	print "size is ", -s _, "\n";	432	print "size is ", -s _, "\n";
399	};	433	};
400		434
		435
		436	=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
		437
		438	Works like perl's C<utime> function (including the special case of $atime
		439	and $mtime being undef). Fractional times are supported if the underlying
		440	syscalls support them.
		441
		442	When called with a pathname, uses utimes(2) if available, otherwise
		443	utime(2). If called on a file descriptor, uses futimes(2) if available,
		444	otherwise returns ENOSYS, so this is not portable.
		445
		446	Examples:
		447
		448	# set atime and mtime to current time (basically touch(1)):
		449	aio_utime "path", undef, undef;
		450	# set atime to current time and mtime to beginning of the epoch:
		451	aio_utime "path", time, undef; # undef==0
		452
		453
		454	=item aio_chown $fh_or_path, $uid, $gid, $callback->($status)
		455
		456	Works like perl's C<chown> function, except that C<undef> for either $uid
		457	or $gid is being interpreted as "do not change" (but -1 can also be used).
		458
		459	Examples:
		460
		461	# same as "chown root path" in the shell:
		462	aio_chown "path", 0, -1;
		463	# same as above:
		464	aio_chown "path", 0, undef;
		465
		466
		467	=item aio_truncate $fh_or_path, $offset, $callback->($status)
		468
		469	Works like truncate(2) or ftruncate(2).
		470
		471
		472	=item aio_chmod $fh_or_path, $mode, $callback->($status)
		473
		474	Works like perl's C<chmod> function.
		475
		476
401	=item aio_unlink $pathname, $callback->($status)	477	=item aio_unlink $pathname, $callback->($status)
402		478
403	Asynchronously unlink (delete) a file and call the callback with the	479	Asynchronously unlink (delete) a file and call the callback with the
404	result code.	480	result code.
405		481
		482
406	=item aio_mknod $path, $mode, $dev, $callback->($status)	483	=item aio_mknod $path, $mode, $dev, $callback->($status)
407		484
408	[EXPERIMENTAL]	485	[EXPERIMENTAL]
409		486
410	Asynchronously create a device node (or fifo). See mknod(2).	487	Asynchronously create a device node (or fifo). See mknod(2).
411		488
412	The only (POSIX-) portable way of calling this function is:	489	The only (POSIX-) portable way of calling this function is:
413		490
414	aio_mknod $path, IO::AIO::S_IFIFO \| $mode, 0, sub { ...	491	aio_mknod $path, IO::AIO::S_IFIFO \| $mode, 0, sub { ...
		492
415		493
416	=item aio_link $srcpath, $dstpath, $callback->($status)	494	=item aio_link $srcpath, $dstpath, $callback->($status)
417		495
418	Asynchronously create a new link to the existing object at C<$srcpath> at	496	Asynchronously create a new link to the existing object at C<$srcpath> at
419	the path C<$dstpath> and call the callback with the result code.	497	the path C<$dstpath> and call the callback with the result code.
420		498
		499
421	=item aio_symlink $srcpath, $dstpath, $callback->($status)	500	=item aio_symlink $srcpath, $dstpath, $callback->($status)
422		501
423	Asynchronously create a new symbolic link to the existing object at C<$srcpath> at	502	Asynchronously create a new symbolic link to the existing object at C<$srcpath> at
424	the path C<$dstpath> and call the callback with the result code.	503	the path C<$dstpath> and call the callback with the result code.
		504
425		505
426	=item aio_readlink $path, $callback->($link)	506	=item aio_readlink $path, $callback->($link)
427		507
428	Asynchronously read the symlink specified by C<$path> and pass it to	508	Asynchronously read the symlink specified by C<$path> and pass it to
429	the callback. If an error occurs, nothing or undef gets passed to the	509	the callback. If an error occurs, nothing or undef gets passed to the
430	callback.	510	callback.
431		511
		512
432	=item aio_rename $srcpath, $dstpath, $callback->($status)	513	=item aio_rename $srcpath, $dstpath, $callback->($status)
433		514
434	Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as	515	Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as
435	rename(2) and call the callback with the result code.	516	rename(2) and call the callback with the result code.
		517
436		518
437	=item aio_mkdir $pathname, $mode, $callback->($status)	519	=item aio_mkdir $pathname, $mode, $callback->($status)
438		520
439	Asynchronously mkdir (create) a directory and call the callback with	521	Asynchronously mkdir (create) a directory and call the callback with
440	the result code. C<$mode> will be modified by the umask at the time the	522	the result code. C<$mode> will be modified by the umask at the time the
441	request is executed, so do not change your umask.	523	request is executed, so do not change your umask.
442		524
		525
443	=item aio_rmdir $pathname, $callback->($status)	526	=item aio_rmdir $pathname, $callback->($status)
444		527
445	Asynchronously rmdir (delete) a directory and call the callback with the	528	Asynchronously rmdir (delete) a directory and call the callback with the
446	result code.	529	result code.
		530
447		531
448	=item aio_readdir $pathname, $callback->($entries)	532	=item aio_readdir $pathname, $callback->($entries)
449		533
450	Unlike the POSIX call of the same name, C<aio_readdir> reads an entire	534	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	535	directory (i.e. opendir + readdir + closedir). The entries will not be
452	sorted, and will B<NOT> include the C<.> and C<..> entries.	536	sorted, and will B<NOT> include the C<.> and C<..> entries.
453		537
454	The callback a single argument which is either C<undef> or an array-ref	538	The callback is passed a single argument which is either C<undef> or an
455	with the filenames.	539	array-ref with the filenames.
		540
		541
		542	=item aio_readdirx $pathname, $flags, $callback->($entries, $flags)
		543
		544	Quite similar to C<aio_readdir>, but the C<$flags> argument allows to tune
		545	behaviour and output format. In case of an error, C<$entries> will be
		546	C<undef>.
		547
		548	The flags are a combination of the following constants, ORed together (the
		549	flags will also be passed to the callback, possibly modified):
		550
		551	=over 4
		552
		553	=item IO::AIO::READDIR_DENTS
		554
		555	When this flag is off, then the callback gets an arrayref with of names
		556	only (as with C<aio_readdir>), otherwise it gets an arrayref with
		557	C<[$name, $type, $inode]> arrayrefs, each describing a single directory
		558	entry in more detail.
		559
		560	C<$name> is the name of the entry.
		561
		562	C<$type> is one of the C<IO::AIO::DT_xxx> constants:
		563
		564	C<IO::AIO::DT_UNKNOWN>, C<IO::AIO::DT_FIFO>, C<IO::AIO::DT_CHR>, C<IO::AIO::DT_DIR>,
		565	C<IO::AIO::DT_BLK>, C<IO::AIO::DT_REG>, C<IO::AIO::DT_LNK>, C<IO::AIO::DT_SOCK>,
		566	C<IO::AIO::DT_WHT>.
		567
		568	C<IO::AIO::DT_UNKNOWN> means just that: readdir does not know. If you need to
		569	know, you have to run stat yourself. Also, for speed reasons, the C<$type>
		570	scalars are read-only: you can not modify them.
		571
		572	C<$inode> is the inode number (which might not be exact on systems with 64
		573	bit inode numbers and 32 bit perls). This field has unspecified content on
		574	systems that do not deliver the inode information.
		575
		576	=item IO::AIO::READDIR_DIRS_FIRST
		577
		578	When this flag is set, then the names will be returned in an order where
		579	likely directories come first. This is useful when you need to quickly
		580	find directories, or you want to find all directories while avoiding to
		581	stat() each entry.
		582
		583	If the system returns type information in readdir, then this is used
		584	to find directories directly. Otherwise, likely directories are files
		585	beginning with ".", or otherwise files with no dots, of which files with
		586	short names are tried first.
		587
		588	=item IO::AIO::READDIR_STAT_ORDER
		589
		590	When this flag is set, then the names will be returned in an order
		591	suitable for stat()'ing each one. That is, when you plan to stat()
		592	all files in the given directory, then the returned order will likely
		593	be fastest.
		594
		595	If both this flag and C<IO::AIO::READDIR_DIRS_FIRST> are specified, then
		596	the likely dirs come first, resulting in a less optimal stat order.
		597
		598	=item IO::AIO::READDIR_FOUND_UNKNOWN
		599
		600	This flag should not be set when calling C<aio_readdirx>. Instead, it
		601	is being set by C<aio_readdirx>, when any of the C<$type>'s found were
		602	C<IO::AIO::DT_UNKNOWN>. The absense of this flag therefore indicates that all
		603	C<$type>'s are known, which can be used to speed up some algorithms.
		604
		605	=back
		606
456		607
457	=item aio_load $path, $data, $callback->($status)	608	=item aio_load $path, $data, $callback->($status)
458		609
459	This is a composite request that tries to fully load the given file into	610	This is a composite request that tries to fully load the given file into
460	memory. Status is the same as with aio_read.	611	memory. Status is the same as with aio_read.
461		612
462	=cut	613	=cut
463		614
464	sub aio_load($$;$) {	615	sub aio_load($$;$) {
465	aio_block {
466	my ($path, undef, $cb) = @_;	616	my ($path, undef, $cb) = @_;
467	my $data = \$_[1];	617	my $data = \$_[1];
468		618
469	my $pri = aioreq_pri;	619	my $pri = aioreq_pri;
470	my $grp = aio_group $cb;	620	my $grp = aio_group $cb;
		621
		622	aioreq_pri $pri;
		623	add $grp aio_open $path, O_RDONLY, 0, sub {
		624	my $fh = shift
		625	or return $grp->result (-1);
471		626
472	aioreq_pri $pri;	627	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), $$data, 0, sub {	628	add $grp aio_read $fh, 0, (-s $fh), $$data, 0, sub {
479	$grp->result ($_[0]);	629	$grp->result ($_[0]);
480	};
481	};	630	};
482
483	$grp
484	}	631	};
		632
		633	$grp
485	}	634	}
486		635
487	=item aio_copy $srcpath, $dstpath, $callback->($status)	636	=item aio_copy $srcpath, $dstpath, $callback->($status)
488		637
489	Try to copy the I<file> (directories not supported as either source or	638	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	639	destination) from C<$srcpath> to C<$dstpath> and call the callback with
491	the C<0> (error) or C<-1> ok.	640	a status of C<0> (ok) or C<-1> (error, see C<$!>).
492		641
493	This is a composite request that it creates the destination file with	642	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	643	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	644	C<aio_sendfile>, followed by restoring atime, mtime, access mode and
496	uid/gid, in that order.	645	uid/gid, in that order.
497		646
498	If an error occurs, the partial destination file will be unlinked, if	647	If an error occurs, the partial destination file will be unlinked, if
…		…
500	errors are being ignored.	649	errors are being ignored.
501		650
502	=cut	651	=cut
503		652
504	sub aio_copy($$;$) {	653	sub aio_copy($$;$) {
505	aio_block {
506	my ($src, $dst, $cb) = @_;	654	my ($src, $dst, $cb) = @_;
507		655
508	my $pri = aioreq_pri;	656	my $pri = aioreq_pri;
509	my $grp = aio_group $cb;	657	my $grp = aio_group $cb;
510		658
511	aioreq_pri $pri;	659	aioreq_pri $pri;
512	add $grp aio_open $src, O_RDONLY, 0, sub {	660	add $grp aio_open $src, O_RDONLY, 0, sub {
513	if (my $src_fh = $_[0]) {	661	if (my $src_fh = $_[0]) {
514	my @stat = stat $src_fh;	662	my @stat = stat $src_fh; # hmm, might block over nfs?
515		663
516	aioreq_pri $pri;	664	aioreq_pri $pri;
517	add $grp aio_open $dst, O_CREAT \| O_WRONLY \| O_TRUNC, 0200, sub {	665	add $grp aio_open $dst, O_CREAT \| O_WRONLY \| O_TRUNC, 0200, sub {
518	if (my $dst_fh = $_[0]) {	666	if (my $dst_fh = $_[0]) {
519	aioreq_pri $pri;	667	aioreq_pri $pri;
520	add $grp aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub {	668	add $grp aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub {
521	if ($_[0] == $stat[7]) {	669	if ($_[0] == $stat[7]) {
522	$grp->result (0);	670	$grp->result (0);
523	close $src_fh;	671	close $src_fh;
524		672
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 {	673	my $ch = sub {
531	$grp->result (-1);
532	close $src_fh;
533	close $dst_fh;
534
535	aioreq $pri;	674	aioreq_pri $pri;
		675	add $grp aio_chmod $dst_fh, $stat[2] & 07777, sub {
		676	aioreq_pri $pri;
		677	add $grp aio_chown $dst_fh, $stat[4], $stat[5], sub {
		678	aioreq_pri $pri;
536	add $grp aio_unlink $dst;	679	add $grp aio_close $dst_fh;
		680	}
		681	};
537	}	682	};
		683
		684	aioreq_pri $pri;
		685	add $grp aio_utime $dst_fh, $stat[8], $stat[9], sub {
		686	if ($_[0] < 0 && $! == ENOSYS) {
		687	aioreq_pri $pri;
		688	add $grp aio_utime $dst, $stat[8], $stat[9], $ch;
		689	} else {
		690	$ch->();
		691	}
		692	};
		693	} else {
		694	$grp->result (-1);
		695	close $src_fh;
		696	close $dst_fh;
		697
		698	aioreq $pri;
		699	add $grp aio_unlink $dst;
538	};	700	}
539	} else {
540	$grp->result (-1);
541	}	701	};
		702	} else {
		703	$grp->result (-1);
542	},	704	}
543
544	} else {
545	$grp->result (-1);
546	}	705	},
		706
		707	} else {
		708	$grp->result (-1);
547	};	709	}
548
549	$grp
550	}	710	};
		711
		712	$grp
551	}	713	}
552		714
553	=item aio_move $srcpath, $dstpath, $callback->($status)	715	=item aio_move $srcpath, $dstpath, $callback->($status)
554		716
555	Try to move the I<file> (directories not supported as either source or	717	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	718	destination) from C<$srcpath> to C<$dstpath> and call the callback with
557	the C<0> (error) or C<-1> ok.	719	a status of C<0> (ok) or C<-1> (error, see C<$!>).
558		720
559	This is a composite request that tries to rename(2) the file first. If	721	This is a composite request that tries to rename(2) the file first; if
560	rename files with C<EXDEV>, it copies the file with C<aio_copy> and, if	722	rename fails with C<EXDEV>, it copies the file with C<aio_copy> and, if
561	that is successful, unlinking the C<$srcpath>.	723	that is successful, unlinks the C<$srcpath>.
562		724
563	=cut	725	=cut
564		726
565	sub aio_move($$;$) {	727	sub aio_move($$;$) {
566	aio_block {
567	my ($src, $dst, $cb) = @_;	728	my ($src, $dst, $cb) = @_;
568		729
569	my $pri = aioreq_pri;	730	my $pri = aioreq_pri;
570	my $grp = aio_group $cb;	731	my $grp = aio_group $cb;
571		732
572	aioreq_pri $pri;	733	aioreq_pri $pri;
573	add $grp aio_rename $src, $dst, sub {	734	add $grp aio_rename $src, $dst, sub {
574	if ($_[0] && $! == EXDEV) {	735	if ($_[0] && $! == EXDEV) {
575	aioreq_pri $pri;	736	aioreq_pri $pri;
576	add $grp aio_copy $src, $dst, sub {	737	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]);	738	$grp->result ($_[0]);
		739
		740	if (!$_[0]) {
		741	aioreq_pri $pri;
		742	add $grp aio_unlink $src;
		743	}
586	}	744	};
		745	} else {
		746	$grp->result ($_[0]);
587	};	747	}
588
589	$grp
590	}	748	};
		749
		750	$grp
591	}	751	}
592		752
593	=item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs)	753	=item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs)
594		754
595	Scans a directory (similar to C<aio_readdir>) but additionally tries to	755	Scans a directory (similar to C<aio_readdir>) but additionally tries to
…		…
615		775
616	Implementation notes.	776	Implementation notes.
617		777
618	The C<aio_readdir> cannot be avoided, but C<stat()>'ing every entry can.	778	The C<aio_readdir> cannot be avoided, but C<stat()>'ing every entry can.
619		779
		780	If readdir returns file type information, then this is used directly to
		781	find directories.
		782
620	After reading the directory, the modification time, size etc. of the	783	Otherwise, after reading the directory, the modification time, size etc.
621	directory before and after the readdir is checked, and if they match (and	784	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	785	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	786	how many entries are directories (if >= 2). Otherwise, no knowledge of the
624	of subdirectories will be assumed.	787	number of subdirectories will be assumed.
625		788
626	Then entries will be sorted into likely directories (everything without	789	Then entries will be sorted into likely directories a non-initial dot
627	a non-initial dot currently) and likely non-directories (everything	790	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,	791	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	792	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	793	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	794	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	795	filesystems might detect the type of the entry without reading the inode
633	data (e.g. ext2fs filetype feature).	796	data (e.g. ext2fs filetype feature), even on systems that cannot return
		797	the filetype information on readdir.
634		798
635	If the known number of directories (link count - 2) has been reached, the	799	If the known number of directories (link count - 2) has been reached, the
636	rest of the entries is assumed to be non-directories.	800	rest of the entries is assumed to be non-directories.
637		801
638	This only works with certainty on POSIX (= UNIX) filesystems, which	802	This only works with certainty on POSIX (= UNIX) filesystems, which
…		…
643	directory counting heuristic.	807	directory counting heuristic.
644		808
645	=cut	809	=cut
646		810
647	sub aio_scandir($$;$) {	811	sub aio_scandir($$;$) {
648	aio_block {
649	my ($path, $maxreq, $cb) = @_;	812	my ($path, $maxreq, $cb) = @_;
650		813
651	my $pri = aioreq_pri;	814	my $pri = aioreq_pri;
652		815
653	my $grp = aio_group $cb;	816	my $grp = aio_group $cb;
654		817
655	$maxreq = 4 if $maxreq <= 0;	818	$maxreq = 4 if $maxreq <= 0;
656		819
657	# stat once	820	# stat once
		821	aioreq_pri $pri;
		822	add $grp aio_stat $path, sub {
		823	return $grp->result () if $_[0];
		824	my $now = time;
		825	my $hash1 = join ":", (stat _)[0,1,3,7,9];
		826
		827	# read the directory entries
658	aioreq_pri $pri;	828	aioreq_pri $pri;
659	add $grp aio_stat $path, sub {	829	add $grp aio_readdirx $path, READDIR_DIRS_FIRST, sub {
		830	my $entries = shift
660	return $grp->result () if $_[0];	831	or return $grp->result ();
661	my $now = time;
662	my $hash1 = join ":", (stat _)[0,1,3,7,9];
663		832
664	# read the directory entries	833	# stat the dir another time
665	aioreq_pri $pri;	834	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 {	835	add $grp aio_stat $path, sub {
673	my $hash2 = join ":", (stat _)[0,1,3,7,9];	836	my $hash2 = join ":", (stat _)[0,1,3,7,9];
674		837
675	my $ndirs;	838	my $ndirs;
676		839
677	# take the slow route if anything looks fishy	840	# take the slow route if anything looks fishy
678	if ($hash1 ne $hash2 or (stat _)[9] == $now) {	841	if ($hash1 ne $hash2 or (stat _)[9] == $now) {
679	$ndirs = -1;	842	$ndirs = -1;
680	} else {	843	} else {
681	# if nlink == 2, we are finished	844	# if nlink == 2, we are finished
682	# on non-posix-fs's, we rely on nlink < 2	845	# for non-posix-fs's, we rely on nlink < 2
683	$ndirs = (stat _)[3] - 2	846	$ndirs = (stat _)[3] - 2
684	or return $grp->result ([], $entries);	847	or return $grp->result ([], $entries);
685	}	848	}
686		849
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);	850	my (@dirs, @nondirs);
695		851
696	my $statgrp = add $grp aio_group sub {	852	my $statgrp = add $grp aio_group sub {
697	$grp->result (\@dirs, \@nondirs);	853	$grp->result (\@dirs, \@nondirs);
698	};	854	};
699		855
700	limit $statgrp $maxreq;	856	limit $statgrp $maxreq;
701	feed $statgrp sub {	857	feed $statgrp sub {
702	return unless @$entries;	858	return unless @$entries;
703	my $entry = pop @$entries;	859	my $entry = shift @$entries;
704		860
705	aioreq_pri $pri;	861	aioreq_pri $pri;
706	add $statgrp aio_stat "$path/$entry/.", sub {	862	add $statgrp aio_stat "$path/$entry/.", sub {
707	if ($_[0] < 0) {	863	if ($_[0] < 0) {
708	push @nondirs, $entry;	864	push @nondirs, $entry;
709	} else {	865	} else {
710	# need to check for real directory	866	# need to check for real directory
711	aioreq_pri $pri;	867	aioreq_pri $pri;
712	add $statgrp aio_lstat "$path/$entry", sub {	868	add $statgrp aio_lstat "$path/$entry", sub {
713	if (-d _) {	869	if (-d _) {
714	push @dirs, $entry;	870	push @dirs, $entry;
715		871
716	unless (--$ndirs) {	872	unless (--$ndirs) {
717	push @nondirs, @$entries;	873	push @nondirs, @$entries;
718	feed $statgrp;	874	feed $statgrp;
719	}
720	} else {
721	push @nondirs, $entry;
722	}	875	}
		876	} else {
		877	push @nondirs, $entry;
723	}	878	}
724	}	879	}
725	};	880	}
726	};	881	};
727	};	882	};
728	};	883	};
729	};	884	};
730
731	$grp
732	}	885	};
		886
		887	$grp
733	}	888	}
734		889
735	=item aio_rmtree $path, $callback->($status)	890	=item aio_rmtree $path, $callback->($status)
736		891
737	Delete a directory tree starting (and including) C<$path>, return the	892	Delete a directory tree starting (and including) C<$path>, return the
…		…
741		896
742	=cut	897	=cut
743		898
744	sub aio_rmtree;	899	sub aio_rmtree;
745	sub aio_rmtree($;$) {	900	sub aio_rmtree($;$) {
746	aio_block {
747	my ($path, $cb) = @_;	901	my ($path, $cb) = @_;
748		902
749	my $pri = aioreq_pri;	903	my $pri = aioreq_pri;
750	my $grp = aio_group $cb;	904	my $grp = aio_group $cb;
751		905
752	aioreq_pri $pri;	906	aioreq_pri $pri;
753	add $grp aio_scandir $path, 0, sub {	907	add $grp aio_scandir $path, 0, sub {
754	my ($dirs, $nondirs) = @_;	908	my ($dirs, $nondirs) = @_;
755		909
756	my $dirgrp = aio_group sub {	910	my $dirgrp = aio_group sub {
757	add $grp aio_rmdir $path, sub {	911	add $grp aio_rmdir $path, sub {
758	$grp->result ($_[0]);	912	$grp->result ($_[0]);
759	};
760	};	913	};
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	};	914	};
767		915
768	$grp	916	(aioreq_pri $pri), add $dirgrp aio_rmtree "$path/$_" for @$dirs;
		917	(aioreq_pri $pri), add $dirgrp aio_unlink "$path/$_" for @$nondirs;
		918
		919	add $grp $dirgrp;
769	}	920	};
		921
		922	$grp
770	}	923	}
		924
		925	=item aio_sync $callback->($status)
		926
		927	Asynchronously call sync and call the callback when finished.
771		928
772	=item aio_fsync $fh, $callback->($status)	929	=item aio_fsync $fh, $callback->($status)
773		930
774	Asynchronously call fsync on the given filehandle and call the callback	931	Asynchronously call fsync on the given filehandle and call the callback
775	with the fsync result code.	932	with the fsync result code.
…		…
779	Asynchronously call fdatasync on the given filehandle and call the	936	Asynchronously call fdatasync on the given filehandle and call the
780	callback with the fdatasync result code.	937	callback with the fdatasync result code.
781		938
782	If this call isn't available because your OS lacks it or it couldn't be	939	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.	940	detected, it will be emulated by calling C<fsync> instead.
		941
		942	=item aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status)
		943
		944	Sync the data portion of the file specified by C<$offset> and C<$length>
		945	to disk (but NOT the metadata), by calling the Linux-specific
		946	sync_file_range call. If sync_file_range is not available or it returns
		947	ENOSYS, then fdatasync or fsync is being substituted.
		948
		949	C<$flags> can be a combination of C<IO::AIO::SYNC_FILE_RANGE_WAIT_BEFORE>,
		950	C<IO::AIO::SYNC_FILE_RANGE_WRITE> and
		951	C<IO::AIO::SYNC_FILE_RANGE_WAIT_AFTER>: refer to the sync_file_range
		952	manpage for details.
		953
		954	=item aio_pathsync $path, $callback->($status)
		955
		956	This request tries to open, fsync and close the given path. This is a
		957	composite request intended to sync directories after directory operations
		958	(E.g. rename). This might not work on all operating systems or have any
		959	specific effect, but usually it makes sure that directory changes get
		960	written to disc. It works for anything that can be opened for read-only,
		961	not just directories.
		962
		963	Future versions of this function might fall back to other methods when
		964	C<fsync> on the directory fails (such as calling C<sync>).
		965
		966	Passes C<0> when everything went ok, and C<-1> on error.
		967
		968	=cut
		969
		970	sub aio_pathsync($;$) {
		971	my ($path, $cb) = @_;
		972
		973	my $pri = aioreq_pri;
		974	my $grp = aio_group $cb;
		975
		976	aioreq_pri $pri;
		977	add $grp aio_open $path, O_RDONLY, 0, sub {
		978	my ($fh) = @_;
		979	if ($fh) {
		980	aioreq_pri $pri;
		981	add $grp aio_fsync $fh, sub {
		982	$grp->result ($_[0]);
		983
		984	aioreq_pri $pri;
		985	add $grp aio_close $fh;
		986	};
		987	} else {
		988	$grp->result (-1);
		989	}
		990	};
		991
		992	$grp
		993	}
784		994
785	=item aio_group $callback->(...)	995	=item aio_group $callback->(...)
786		996
787	This is a very special aio request: Instead of doing something, it is a	997	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	998	container for other aio requests, which is useful if you want to bundle
…		…
838	=item cancel $req	1048	=item cancel $req
839		1049
840	Cancels the request, if possible. Has the effect of skipping execution	1050	Cancels the request, if possible. Has the effect of skipping execution
841	when entering the B<execute> state and skipping calling the callback when	1051	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	1052	entering the the B<result> state, but will leave the request otherwise
843	untouched. That means that requests that currently execute will not be	1053	untouched (with the exception of readdir). That means that requests that
844	stopped and resources held by the request will not be freed prematurely.	1054	currently execute will not be stopped and resources held by the request
		1055	will not be freed prematurely.
845		1056
846	=item cb $req $callback->(...)	1057	=item cb $req $callback->(...)
847		1058
848	Replace (or simply set) the callback registered to the request.	1059	Replace (or simply set) the callback registered to the request.
849		1060
…		…
900	Their lifetime, simplified, looks like this: when they are empty, they	1111	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	1112	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	1113	C<done> state, they will also finish. Otherwise they will continue to
903	exist.	1114	exist.
904		1115
905	That means after creating a group you have some time to add requests. And	1116	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	1117	(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	1118	the C<poll_cb>). And in the callbacks of those requests, you can add
908	itself finish.	1119	further requests to the group. And only when all those requests have
		1120	finished will the the group itself finish.
909		1121
910	=over 4	1122	=over 4
911		1123
912	=item add $grp ...	1124	=item add $grp ...
913		1125
…		…
922	=item $grp->cancel_subs	1134	=item $grp->cancel_subs
923		1135
924	Cancel all subrequests and clears any feeder, but not the group request	1136	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.	1137	itself. Useful when you queued a lot of events but got a result early.
926		1138
		1139	The group request will finish normally (you cannot add requests to the
		1140	group).
		1141
927	=item $grp->result (...)	1142	=item $grp->result (...)
928		1143
929	Set the result value(s) that will be passed to the group callback when all	1144	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	1145	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,	1146	of errno (just like calling C<errno> without an error number). By default,
932	no argument will be passed and errno is zero.	1147	no argument will be passed and errno is zero.
933		1148
934	=item $grp->errno ([$errno])	1149	=item $grp->errno ([$errno])
935		1150
…		…
946	=item feed $grp $callback->($grp)	1161	=item feed $grp $callback->($grp)
947		1162
948	Sets a feeder/generator on this group: every group can have an attached	1163	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,	1164	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,	1165	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	1166	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>	1167	C<aio_scandir> might generate hundreds of thousands C<aio_stat> requests,
953	requests, delaying any later requests for a long time.	1168	delaying any later requests for a long time.
954		1169
955	To avoid this, and allow incremental generation of requests, you can	1170	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	1171	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>,	1172	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	1173	below) requests active in the group itself and is expected to queue more
…		…
962	not impose any limits).	1177	not impose any limits).
963		1178
964	If the feed does not queue more requests when called, it will be	1179	If the feed does not queue more requests when called, it will be
965	automatically removed from the group.	1180	automatically removed from the group.
966		1181
967	If the feed limit is C<0>, it will be set to C<2> automatically.	1182	If the feed limit is C<0> when this method is called, it will be set to
		1183	C<2> automatically.
968		1184
969	Example:	1185	Example:
970		1186
971	# stat all files in @files, but only ever use four aio requests concurrently:	1187	# stat all files in @files, but only ever use four aio requests concurrently:
972		1188
…		…
984	Sets the feeder limit for the group: The feeder will be called whenever	1200	Sets the feeder limit for the group: The feeder will be called whenever
985	the group contains less than this many requests.	1201	the group contains less than this many requests.
986		1202
987	Setting the limit to C<0> will pause the feeding process.	1203	Setting the limit to C<0> will pause the feeding process.
988		1204
		1205	The default value for the limit is C<0>, but note that setting a feeder
		1206	automatically bumps it up to C<2>.
		1207
989	=back	1208	=back
990		1209
991	=head2 SUPPORT FUNCTIONS	1210	=head2 SUPPORT FUNCTIONS
992		1211
993	=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION	1212	=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION
…		…
995	=over 4	1214	=over 4
996		1215
997	=item $fileno = IO::AIO::poll_fileno	1216	=item $fileno = IO::AIO::poll_fileno
998		1217
999	Return the I<request result pipe file descriptor>. This filehandle must be	1218	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	1219	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	1220	select and so on, see below or the SYNOPSIS). If the pipe becomes readable
1002	to call C<poll_cb> to check the results.	1221	you have to call C<poll_cb> to check the results.
1003		1222
1004	See C<poll_cb> for an example.	1223	See C<poll_cb> for an example.
1005		1224
1006	=item IO::AIO::poll_cb	1225	=item IO::AIO::poll_cb
1007		1226
1008	Process some outstanding events on the result pipe. You have to call this	1227	Process some outstanding events on the result pipe. You have to call this
1009	regularly. Returns the number of events processed. Returns immediately	1228	regularly. Returns C<0> if all events could be processed, or C<-1> if it
		1229	returned earlier for whatever reason. Returns immediately when no events
1010	when no events are outstanding. The amount of events processed depends on	1230	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>.	1231	C<IO::AIO::max_poll_req> and C<IO::AIO::max_poll_time>.
1012		1232
1013	If not all requests were processed for whatever reason, the filehandle	1233	If not all requests were processed for whatever reason, the filehandle
1014	will still be ready when C<poll_cb> returns.	1234	will still be ready when C<poll_cb> returns, so normally you don't have to
		1235	do anything special to have it called later.
1015		1236
1016	Example: Install an Event watcher that automatically calls	1237	Example: Install an Event watcher that automatically calls
1017	IO::AIO::poll_cb with high priority:	1238	IO::AIO::poll_cb with high priority (more examples can be found in the
		1239	SYNOPSIS section, at the top of this document):
1018		1240
1019	Event->io (fd => IO::AIO::poll_fileno,	1241	Event->io (fd => IO::AIO::poll_fileno,
1020	poll => 'r', async => 1,	1242	poll => 'r', async => 1,
1021	cb => \&IO::AIO::poll_cb);	1243	cb => \&IO::AIO::poll_cb);
1022		1244
…		…
1133		1355
1134	The default is probably ok in most situations, especially if thread	1356	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	1357	creation is fast. If thread creation is very slow on your system you might
1136	want to use larger values.	1358	want to use larger values.
1137		1359
1138	=item $oldmaxreqs = IO::AIO::max_outstanding $maxreqs	1360	=item IO::AIO::max_outstanding $maxreqs
1139		1361
1140	This is a very bad function to use in interactive programs because it	1362	This is a very bad function to use in interactive programs because it
1141	blocks, and a bad way to reduce concurrency because it is inexact: Better	1363	blocks, and a bad way to reduce concurrency because it is inexact: Better
1142	use an C<aio_group> together with a feed callback.	1364	use an C<aio_group> together with a feed callback.
1143		1365
1144	Sets the maximum number of outstanding requests to C<$nreqs>. If you	1366	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	1367	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>)	1368	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.	1369	function will block until the limit is no longer exceeded.
1148		1370
1149	The default value is very large, so there is no practical limit on the	1371	The default value is very large, so there is no practical limit on the
1150	number of outstanding requests.	1372	number of outstanding requests.
1151		1373
1152	You can still queue as many requests as you want. Therefore,	1374	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	1375	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).	1376	as a stop gap to shield against fatal memory overflow (with large values).
1155		1377
1156	=back	1378	=back
1157		1379
1158	=head3 STATISTICAL INFORMATION	1380	=head3 STATISTICAL INFORMATION
…		…
1179	Returns the number of requests currently in the pending state (executed,	1401	Returns the number of requests currently in the pending state (executed,
1180	but not yet processed by poll_cb).	1402	but not yet processed by poll_cb).
1181		1403
1182	=back	1404	=back
1183		1405
		1406	=head3 MISCELLANEOUS FUNCTIONS
		1407
		1408	IO::AIO implements some functions that might be useful, but are not
		1409	asynchronous.
		1410
		1411	=over 4
		1412
		1413	=item IO::AIO::sendfile $ofh, $ifh, $offset, $count
		1414
		1415	Calls the C<eio_sendfile_sync> function, which is like C<aio_sendfile>,
		1416	but is blocking (this makes most sense if you know the input data is
		1417	likely cached already and the output filehandle is set to non-blocking
		1418	operations).
		1419
		1420	Returns the number of bytes copied, or C<-1> on error.
		1421
		1422	=item IO::AIO::fadvise $fh, $offset, $len, $advice
		1423
		1424	Simply calls the C<posix_fadvise> function (see it's
		1425	manpage for details). The following advice constants are
		1426	avaiable: C<IO::AIO::FADV_NORMAL>, C<IO::AIO::FADV_SEQUENTIAL>,
		1427	C<IO::AIO::FADV_RANDOM>, C<IO::AIO::FADV_NOREUSE>,
		1428	C<IO::AIO::FADV_WILLNEED>, C<IO::AIO::FADV_DONTNEED>.
		1429
		1430	On systems that do not implement C<posix_fadvise>, this function returns
		1431	ENOSYS, otherwise the return value of C<posix_fadvise>.
		1432
		1433	=back
		1434
1184	=cut	1435	=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		1436
1202	min_parallel 8;	1437	min_parallel 8;
1203		1438
1204	END { flush }	1439	END { flush }
1205		1440
…		…
1229	bytes of memory. In addition, stat requests need a stat buffer (possibly	1464	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	1465	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	1466	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.	1467	will consume memory till the request has entered the done state.
1233		1468
1234	This is now awfully much, so queuing lots of requests is not usually a	1469	This is not awfully much, so queuing lots of requests is not usually a
1235	problem.	1470	problem.
1236		1471
1237	Per-thread usage:	1472	Per-thread usage:
1238		1473
1239	In the execution phase, some aio requests require more memory for	1474	In the execution phase, some aio requests require more memory for
…		…
1244		1479
1245	Known bugs will be fixed in the next release.	1480	Known bugs will be fixed in the next release.
1246		1481
1247	=head1 SEE ALSO	1482	=head1 SEE ALSO
1248		1483
1249	L<Coro::AIO>.	1484	L<AnyEvent::AIO> for easy integration into event loops, L<Coro::AIO> for a
		1485	more natural syntax.
1250		1486
1251	=head1 AUTHOR	1487	=head1 AUTHOR
1252		1488
1253	Marc Lehmann <schmorp@schmorp.de>	1489	Marc Lehmann <schmorp@schmorp.de>
1254	http://home.schmorp.de/	1490	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 1.169 by root, Sat Jan 2 13:02:20 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 1.169 by root, Sat Jan 2 13:02:20 2010 UTC