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

Comparing IO-AIO/AIO.pm (file contents):
Revision 1.91 by root, Mon Oct 30 23:30:29 2006 UTC vs.
Revision 1.173 by root, Thu Jan 7 20:25:57 2010 UTC

…		…
5	=head1 SYNOPSIS	5	=head1 SYNOPSIS
6		6
7	use IO::AIO;	7	use IO::AIO;
8		8
9	aio_open "/etc/passwd", O_RDONLY, 0, sub {	9	aio_open "/etc/passwd", O_RDONLY, 0, sub {
10	my ($fh) = @_;	10	my $fh = shift
		11	or die "/etc/passwd: $!";
11	...	12	...
12	};	13	};
13		14
14	aio_unlink "/tmp/file", sub { };	15	aio_unlink "/tmp/file", sub { };
15		16
…		…
25	$req->cancel; # cancel request if still in queue	26	$req->cancel; # cancel request if still in queue
26		27
27	my $grp = aio_group sub { print "all stats done\n" };	28	my $grp = aio_group sub { print "all stats done\n" };
28	add $grp aio_stat "..." for ...;	29	add $grp aio_stat "..." for ...;
29		30
		31	# AnyEvent integration (EV, Event, Glib, Tk, POE, urxvt, pureperl...)
		32	use AnyEvent::AIO;
		33
30	# AnyEvent integration	34	# EV integration
31	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;
32	my $w = AnyEvent->io (fh => $fh, poll => 'r', cb => sub { IO::AIO::poll_cb });
33		36
34	# Event integration	37	# Event integration
35	Event->io (fd => IO::AIO::poll_fileno,	38	Event->io (fd => IO::AIO::poll_fileno,
36	poll => 'r',	39	poll => 'r',
37	cb => \&IO::AIO::poll_cb);	40	cb => \&IO::AIO::poll_cb);
…		…
49	\&IO::AIO::poll_cb);	52	\&IO::AIO::poll_cb);
50		53
51	=head1 DESCRIPTION	54	=head1 DESCRIPTION
52		55
53	This module implements asynchronous I/O using whatever means your	56	This module implements asynchronous I/O using whatever means your
54	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>).
55		59
56	Asynchronous means that operations that can normally block your program	60	Asynchronous means that operations that can normally block your program
57	(e.g. reading from disk) will be done asynchronously: the operation	61	(e.g. reading from disk) will be done asynchronously: the operation
58	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
59	is extremely useful for programs that need to stay interactive even	63	is extremely useful for programs that need to stay interactive even
…		…
61	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
62	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
63	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
64	concurrently.	68	concurrently.
65		69
66	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
67	sockets), using these functions on file descriptors that support	71	example sockets), using these functions on file descriptors that
68	nonblocking operation (again, sockets, pipes etc.) is very inefficient or	72	support nonblocking operation (again, sockets, pipes etc.) is
69	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>
70	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.
71	into such an event loop itself.
72		75
73	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
74	requests and signal their completion. You don't need thread support	77	requests and signal their completion. You don't need thread support
75	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
76	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
…		…
78	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
79	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
80	aio_write, so the remaining functionality would have to be implemented	83	aio_write, so the remaining functionality would have to be implemented
81	using threads anyway.	84	using threads anyway.
82		85
83	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,
84	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
85	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
86	never call C<poll_cb> (or other C<aio_> functions) recursively.	89	call C<poll_cb> (or other C<aio_> functions) recursively.
87		90
88	=head2 EXAMPLE	91	=head2 EXAMPLE
89		92
90	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
91	F</etc/passwd> asynchronously:	94	F</etc/passwd> asynchronously:
92		95
93	use Fcntl;	96	use Fcntl;
94	use Event;	97	use EV;
95	use IO::AIO;	98	use IO::AIO;
96		99
97	# register the IO::AIO callback with Event	100	# register the IO::AIO callback with EV
98	Event->io (fd => IO::AIO::poll_fileno,	101	my $aio_w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb;
99	poll => 'r',
100	cb => \&IO::AIO::poll_cb);
101		102
102	# queue the request to open /etc/passwd	103	# queue the request to open /etc/passwd
103	aio_open "/etc/passwd", O_RDONLY, 0, sub {	104	aio_open "/etc/passwd", O_RDONLY, 0, sub {
104	my $fh = $_[0]	105	my $fh = shift
105	or die "error while opening: $!";	106	or die "error while opening: $!";
106		107
107	# stat'ing filehandles is generally non-blocking	108	# stat'ing filehandles is generally non-blocking
108	my $size = -s $fh;	109	my $size = -s $fh;
109		110
…		…
117		118
118	# file contents now in $contents	119	# file contents now in $contents
119	print $contents;	120	print $contents;
120		121
121	# exit event loop and program	122	# exit event loop and program
122	Event::unloop;	123	EV::unloop;
123	};	124	};
124	};	125	};
125		126
126	# possibly queue up other requests, or open GUI windows,	127	# possibly queue up other requests, or open GUI windows,
127	# check for sockets etc. etc.	128	# check for sockets etc. etc.
128		129
129	# process events as long as there are some:	130	# process events as long as there are some:
130	Event::loop;	131	EV::loop;
131		132
132	=head1 REQUEST ANATOMY AND LIFETIME	133	=head1 REQUEST ANATOMY AND LIFETIME
133		134
134	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
135	directly visible to Perl.	136	directly visible to Perl.
…		…
183		184
184	=cut	185	=cut
185		186
186	package IO::AIO;	187	package IO::AIO;
187		188
188	no warnings;	189	use Carp ();
189	use strict 'vars';	190
		191	use common::sense;
190		192
191	use base 'Exporter';	193	use base 'Exporter';
192		194
193	BEGIN {	195	BEGIN {
194	our $VERSION = '2.2';	196	our $VERSION = '3.5';
195		197
196	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
197	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
198	aio_readlink aio_fsync aio_fdatasync aio_readahead aio_rename aio_link	200	aio_scandir aio_symlink aio_readlink aio_sync aio_fsync
199	aio_move aio_copy aio_group aio_nop aio_mknod);	201	aio_fdatasync aio_sync_file_range aio_pathsync aio_readahead
		202	aio_rename aio_link aio_move aio_copy aio_group
		203	aio_nop aio_mknod aio_load aio_rmtree aio_mkdir aio_chown
		204	aio_chmod aio_utime aio_truncate
		205	aio_msync aio_mtouch aio_statvfs);
		206
200	our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice));	207	our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice));
201	our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush	208	our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush
202	min_parallel max_parallel max_idle	209	min_parallel max_parallel max_idle
203	nreqs nready npending nthreads	210	nreqs nready npending nthreads
204	max_poll_time max_poll_reqs);	211	max_poll_time max_poll_reqs
		212	sendfile fadvise);
		213
		214	push @AIO_REQ, qw(aio_busy); # not exported
205		215
206	@IO::AIO::GRP::ISA = 'IO::AIO::REQ';	216	@IO::AIO::GRP::ISA = 'IO::AIO::REQ';
207		217
208	require XSLoader;	218	require XSLoader;
209	XSLoader::load ("IO::AIO", $VERSION);	219	XSLoader::load ("IO::AIO", $VERSION);
…		…
216	All the C<aio_*> calls are more or less thin wrappers around the syscall	226	All the C<aio_*> calls are more or less thin wrappers around the syscall
217	with the same name (sans C<aio_>). The arguments are similar or identical,	227	with the same name (sans C<aio_>). The arguments are similar or identical,
218	and they all accept an additional (and optional) C<$callback> argument	228	and they all accept an additional (and optional) C<$callback> argument
219	which must be a code reference. This code reference will get called with	229	which must be a code reference. This code reference will get called with
220	the syscall return code (e.g. most syscalls return C<-1> on error, unlike	230	the syscall return code (e.g. most syscalls return C<-1> on error, unlike
221	perl, which usually delivers "false") as it's sole argument when the given	231	perl, which usually delivers "false") as its sole argument after the given
222	syscall has been executed asynchronously.	232	syscall has been executed asynchronously.
223		233
224	All functions expecting a filehandle keep a copy of the filehandle	234	All functions expecting a filehandle keep a copy of the filehandle
225	internally until the request has finished.	235	internally until the request has finished.
226		236
…		…
240	your pathnames to the locale (or other) encoding in effect in the user	250	your pathnames to the locale (or other) encoding in effect in the user
241	environment, d) use Glib::filename_from_unicode on unicode filenames or e)	251	environment, d) use Glib::filename_from_unicode on unicode filenames or e)
242	use something else to ensure your scalar has the correct contents.	252	use something else to ensure your scalar has the correct contents.
243		253
244	This works, btw. independent of the internal UTF-8 bit, which IO::AIO	254	This works, btw. independent of the internal UTF-8 bit, which IO::AIO
245	handles correctly wether it is set or not.	255	handles correctly whether it is set or not.
246		256
247	=over 4	257	=over 4
248		258
249	=item $prev_pri = aioreq_pri [$pri]	259	=item $prev_pri = aioreq_pri [$pri]
250		260
…		…
270	aio_read $_[0], ..., sub {	280	aio_read $_[0], ..., sub {
271	...	281	...
272	};	282	};
273	};	283	};
274		284
		285
275	=item aioreq_nice $pri_adjust	286	=item aioreq_nice $pri_adjust
276		287
277	Similar to C<aioreq_pri>, but subtracts the given value from the current	288	Similar to C<aioreq_pri>, but subtracts the given value from the current
278	priority, so the effect is cumulative.	289	priority, so the effect is cumulative.
		290
279		291
280	=item aio_open $pathname, $flags, $mode, $callback->($fh)	292	=item aio_open $pathname, $flags, $mode, $callback->($fh)
281		293
282	Asynchronously open or create a file and call the callback with a newly	294	Asynchronously open or create a file and call the callback with a newly
283	created filehandle for the file.	295	created filehandle for the file.
…		…
289	list. They are the same as used by C<sysopen>.	301	list. They are the same as used by C<sysopen>.
290		302
291	Likewise, C<$mode> specifies the mode of the newly created file, if it	303	Likewise, C<$mode> specifies the mode of the newly created file, if it
292	didn't exist and C<O_CREAT> has been given, just like perl's C<sysopen>,	304	didn't exist and C<O_CREAT> has been given, just like perl's C<sysopen>,
293	except that it is mandatory (i.e. use C<0> if you don't create new files,	305	except that it is mandatory (i.e. use C<0> if you don't create new files,
294	and C<0666> or C<0777> if you do).	306	and C<0666> or C<0777> if you do). Note that the C<$mode> will be modified
		307	by the umask in effect then the request is being executed, so better never
		308	change the umask.
295		309
296	Example:	310	Example:
297		311
298	aio_open "/etc/passwd", O_RDONLY, 0, sub {	312	aio_open "/etc/passwd", O_RDONLY, 0, sub {
299	if ($_[0]) {	313	if ($_[0]) {
…		…
302	} else {	316	} else {
303	die "open failed: $!\n";	317	die "open failed: $!\n";
304	}	318	}
305	};	319	};
306		320
		321
307	=item aio_close $fh, $callback->($status)	322	=item aio_close $fh, $callback->($status)
308		323
309	Asynchronously close a file and call the callback with the result	324	Asynchronously close a file and call the callback with the result
310	code. I<WARNING:> although accepted, you should not pass in a perl	325	code.
311	filehandle here, as perl will likely close the file descriptor another
312	time when the filehandle is destroyed. Normally, you can safely call perls
313	C<close> or just let filehandles go out of scope.
314		326
315	This is supposed to be a bug in the API, so that might change. It's	327	Unfortunately, you can't do this to perl. Perl I<insists> very strongly on
316	therefore best to avoid this function.	328	closing the file descriptor associated with the filehandle itself.
		329
		330	Therefore, C<aio_close> will not close the filehandle - instead it will
		331	use dup2 to overwrite the file descriptor with the write-end of a pipe
		332	(the pipe fd will be created on demand and will be cached).
		333
		334	Or in other words: the file descriptor will be closed, but it will not be
		335	free for reuse until the perl filehandle is closed.
		336
		337	=cut
317		338
318	=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)	339	=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
319		340
320	=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)	341	=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
321		342
322	Reads or writes C<length> bytes from the specified C<fh> and C<offset>	343	Reads or writes C<$length> bytes from or to the specified C<$fh> and
323	into the scalar given by C<data> and offset C<dataoffset> and calls the	344	C<$offset> into the scalar given by C<$data> and offset C<$dataoffset>
324	callback without the actual number of bytes read (or -1 on error, just	345	and calls the callback without the actual number of bytes read (or -1 on
325	like the syscall).	346	error, just like the syscall).
		347
		348	C<aio_read> will, like C<sysread>, shrink or grow the C<$data> scalar to
		349	offset plus the actual number of bytes read.
		350
		351	If C<$offset> is undefined, then the current file descriptor offset will
		352	be used (and updated), otherwise the file descriptor offset will not be
		353	changed by these calls.
		354
		355	If C<$length> is undefined in C<aio_write>, use the remaining length of
		356	C<$data>.
		357
		358	If C<$dataoffset> is less than zero, it will be counted from the end of
		359	C<$data>.
326		360
327	The C<$data> scalar I<MUST NOT> be modified in any way while the request	361	The C<$data> scalar I<MUST NOT> be modified in any way while the request
328	is outstanding. Modifying it can result in segfaults or WW3 (if the	362	is outstanding. Modifying it can result in segfaults or World War III (if
329	necessary/optional hardware is installed).	363	the necessary/optional hardware is installed).
330		364
331	Example: Read 15 bytes at offset 7 into scalar C<$buffer>, starting at	365	Example: Read 15 bytes at offset 7 into scalar C<$buffer>, starting at
332	offset C<0> within the scalar:	366	offset C<0> within the scalar:
333		367
334	aio_read $fh, 7, 15, $buffer, 0, sub {	368	aio_read $fh, 7, 15, $buffer, 0, sub {
335	$_[0] > 0 or die "read error: $!";	369	$_[0] > 0 or die "read error: $!";
336	print "read $_[0] bytes: <$buffer>\n";	370	print "read $_[0] bytes: <$buffer>\n";
337	};	371	};
		372
338		373
339	=item aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval)	374	=item aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval)
340		375
341	Tries to copy C<$length> bytes from C<$in_fh> to C<$out_fh>. It starts	376	Tries to copy C<$length> bytes from C<$in_fh> to C<$out_fh>. It starts
342	reading at byte offset C<$in_offset>, and starts writing at the current	377	reading at byte offset C<$in_offset>, and starts writing at the current
…		…
346		381
347	This call tries to make use of a native C<sendfile> syscall to provide	382	This call tries to make use of a native C<sendfile> syscall to provide
348	zero-copy operation. For this to work, C<$out_fh> should refer to a	383	zero-copy operation. For this to work, C<$out_fh> should refer to a
349	socket, and C<$in_fh> should refer to mmap'able file.	384	socket, and C<$in_fh> should refer to mmap'able file.
350		385
351	If the native sendfile call fails or is not implemented, it will be	386	If a native sendfile cannot be found or it fails with C<ENOSYS>,
		387	C<ENOTSUP>, C<EOPNOTSUPP>, C<EAFNOSUPPORT>, C<EPROTOTYPE> or C<ENOTSOCK>,
352	emulated, so you can call C<aio_sendfile> on any type of filehandle	388	it will be emulated, so you can call C<aio_sendfile> on any type of
353	regardless of the limitations of the operating system.	389	filehandle regardless of the limitations of the operating system.
354		390
355	Please note, however, that C<aio_sendfile> can read more bytes from	391	Please note, however, that C<aio_sendfile> can read more bytes from
356	C<$in_fh> than are written, and there is no way to find out how many	392	C<$in_fh> than are written, and there is no way to find out how many
357	bytes have been read from C<aio_sendfile> alone, as C<aio_sendfile> only	393	bytes have been read from C<aio_sendfile> alone, as C<aio_sendfile> only
358	provides the number of bytes written to C<$out_fh>. Only if the result	394	provides the number of bytes written to C<$out_fh>. Only if the result
359	value equals C<$length> one can assume that C<$length> bytes have been	395	value equals C<$length> one can assume that C<$length> bytes have been
360	read.	396	read.
		397
361		398
362	=item aio_readahead $fh,$offset,$length, $callback->($retval)	399	=item aio_readahead $fh,$offset,$length, $callback->($retval)
363		400
364	C<aio_readahead> populates the page cache with data from a file so that	401	C<aio_readahead> populates the page cache with data from a file so that
365	subsequent reads from that file will not block on disk I/O. The C<$offset>	402	subsequent reads from that file will not block on disk I/O. The C<$offset>
…		…
371	file. The current file offset of the file is left unchanged.	408	file. The current file offset of the file is left unchanged.
372		409
373	If that syscall doesn't exist (likely if your OS isn't Linux) it will be	410	If that syscall doesn't exist (likely if your OS isn't Linux) it will be
374	emulated by simply reading the data, which would have a similar effect.	411	emulated by simply reading the data, which would have a similar effect.
375		412
		413
376	=item aio_stat $fh_or_path, $callback->($status)	414	=item aio_stat $fh_or_path, $callback->($status)
377		415
378	=item aio_lstat $fh, $callback->($status)	416	=item aio_lstat $fh, $callback->($status)
379		417
380	Works like perl's C<stat> or C<lstat> in void context. The callback will	418	Works like perl's C<stat> or C<lstat> in void context. The callback will
…		…
393	aio_stat "/etc/passwd", sub {	431	aio_stat "/etc/passwd", sub {
394	$_[0] and die "stat failed: $!";	432	$_[0] and die "stat failed: $!";
395	print "size is ", -s _, "\n";	433	print "size is ", -s _, "\n";
396	};	434	};
397		435
		436
		437	=item aio_statvfs $fh_or_path, $callback->($statvfs)
		438
		439	Works like the POSIX C<statvfs> or C<fstatvfs> syscalls, depending on
		440	whether a file handle or path was passed.
		441
		442	On success, the callback is passed a hash reference with the following
		443	members: C<bsize>, C<frsize>, C<blocks>, C<bfree>, C<bavail>, C<files>,
		444	C<ffree>, C<favail>, C<fsid>, C<flag> and C<namemax>. On failure, C<undef>
		445	is passed.
		446
		447	The following POSIX IO::AIO::ST_* constants are defined: C<ST_RDONLY> and
		448	C<ST_NOSUID>.
		449
		450	The following non-POSIX IO::AIO::ST_* flag masks are defined to
		451	their correct value when available, or to C<0> on systems that do
		452	not support them: C<ST_NODEV>, C<ST_NOEXEC>, C<ST_SYNCHRONOUS>,
		453	C<ST_MANDLOCK>, C<ST_WRITE>, C<ST_APPEND>, C<ST_IMMUTABLE>, C<ST_NOATIME>,
		454	C<ST_NODIRATIME> and C<ST_RELATIME>.
		455
		456	Example: stat C</wd> and dump out the data if successful.
		457
		458	aio_statvfs "/wd", sub {
		459	my $f = $_[0]
		460	or die "statvfs: $!";
		461
		462	use Data::Dumper;
		463	say Dumper $f;
		464	};
		465
		466	# result:
		467	{
		468	bsize => 1024,
		469	bfree => 4333064312,
		470	blocks => 10253828096,
		471	files => 2050765568,
		472	flag => 4096,
		473	favail => 2042092649,
		474	bavail => 4333064312,
		475	ffree => 2042092649,
		476	namemax => 255,
		477	frsize => 1024,
		478	fsid => 1810
		479	}
		480
		481
		482	=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
		483
		484	Works like perl's C<utime> function (including the special case of $atime
		485	and $mtime being undef). Fractional times are supported if the underlying
		486	syscalls support them.
		487
		488	When called with a pathname, uses utimes(2) if available, otherwise
		489	utime(2). If called on a file descriptor, uses futimes(2) if available,
		490	otherwise returns ENOSYS, so this is not portable.
		491
		492	Examples:
		493
		494	# set atime and mtime to current time (basically touch(1)):
		495	aio_utime "path", undef, undef;
		496	# set atime to current time and mtime to beginning of the epoch:
		497	aio_utime "path", time, undef; # undef==0
		498
		499
		500	=item aio_chown $fh_or_path, $uid, $gid, $callback->($status)
		501
		502	Works like perl's C<chown> function, except that C<undef> for either $uid
		503	or $gid is being interpreted as "do not change" (but -1 can also be used).
		504
		505	Examples:
		506
		507	# same as "chown root path" in the shell:
		508	aio_chown "path", 0, -1;
		509	# same as above:
		510	aio_chown "path", 0, undef;
		511
		512
		513	=item aio_truncate $fh_or_path, $offset, $callback->($status)
		514
		515	Works like truncate(2) or ftruncate(2).
		516
		517
		518	=item aio_chmod $fh_or_path, $mode, $callback->($status)
		519
		520	Works like perl's C<chmod> function.
		521
		522
398	=item aio_unlink $pathname, $callback->($status)	523	=item aio_unlink $pathname, $callback->($status)
399		524
400	Asynchronously unlink (delete) a file and call the callback with the	525	Asynchronously unlink (delete) a file and call the callback with the
401	result code.	526	result code.
402		527
		528
403	=item aio_mknod $path, $mode, $dev, $callback->($status)	529	=item aio_mknod $path, $mode, $dev, $callback->($status)
404		530
405	[EXPERIMENTAL]	531	[EXPERIMENTAL]
406		532
407	Asynchronously create a device node (or fifo). See mknod(2).	533	Asynchronously create a device node (or fifo). See mknod(2).
408		534
409	The only (POSIX-) portable way of calling this function is:	535	The only (POSIX-) portable way of calling this function is:
410		536
411	aio_mknod $path, IO::AIO::S_IFIFO \| $mode, 0, sub { ...	537	aio_mknod $path, IO::AIO::S_IFIFO \| $mode, 0, sub { ...
		538
412		539
413	=item aio_link $srcpath, $dstpath, $callback->($status)	540	=item aio_link $srcpath, $dstpath, $callback->($status)
414		541
415	Asynchronously create a new link to the existing object at C<$srcpath> at	542	Asynchronously create a new link to the existing object at C<$srcpath> at
416	the path C<$dstpath> and call the callback with the result code.	543	the path C<$dstpath> and call the callback with the result code.
417		544
		545
418	=item aio_symlink $srcpath, $dstpath, $callback->($status)	546	=item aio_symlink $srcpath, $dstpath, $callback->($status)
419		547
420	Asynchronously create a new symbolic link to the existing object at C<$srcpath> at	548	Asynchronously create a new symbolic link to the existing object at C<$srcpath> at
421	the path C<$dstpath> and call the callback with the result code.	549	the path C<$dstpath> and call the callback with the result code.
		550
422		551
423	=item aio_readlink $path, $callback->($link)	552	=item aio_readlink $path, $callback->($link)
424		553
425	Asynchronously read the symlink specified by C<$path> and pass it to	554	Asynchronously read the symlink specified by C<$path> and pass it to
426	the callback. If an error occurs, nothing or undef gets passed to the	555	the callback. If an error occurs, nothing or undef gets passed to the
427	callback.	556	callback.
428		557
		558
429	=item aio_rename $srcpath, $dstpath, $callback->($status)	559	=item aio_rename $srcpath, $dstpath, $callback->($status)
430		560
431	Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as	561	Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as
432	rename(2) and call the callback with the result code.	562	rename(2) and call the callback with the result code.
433		563
		564
		565	=item aio_mkdir $pathname, $mode, $callback->($status)
		566
		567	Asynchronously mkdir (create) a directory and call the callback with
		568	the result code. C<$mode> will be modified by the umask at the time the
		569	request is executed, so do not change your umask.
		570
		571
434	=item aio_rmdir $pathname, $callback->($status)	572	=item aio_rmdir $pathname, $callback->($status)
435		573
436	Asynchronously rmdir (delete) a directory and call the callback with the	574	Asynchronously rmdir (delete) a directory and call the callback with the
437	result code.	575	result code.
		576
438		577
439	=item aio_readdir $pathname, $callback->($entries)	578	=item aio_readdir $pathname, $callback->($entries)
440		579
441	Unlike the POSIX call of the same name, C<aio_readdir> reads an entire	580	Unlike the POSIX call of the same name, C<aio_readdir> reads an entire
442	directory (i.e. opendir + readdir + closedir). The entries will not be	581	directory (i.e. opendir + readdir + closedir). The entries will not be
443	sorted, and will B<NOT> include the C<.> and C<..> entries.	582	sorted, and will B<NOT> include the C<.> and C<..> entries.
444		583
445	The callback a single argument which is either C<undef> or an array-ref	584	The callback is passed a single argument which is either C<undef> or an
446	with the filenames.	585	array-ref with the filenames.
		586
		587
		588	=item aio_readdirx $pathname, $flags, $callback->($entries, $flags)
		589
		590	Quite similar to C<aio_readdir>, but the C<$flags> argument allows to tune
		591	behaviour and output format. In case of an error, C<$entries> will be
		592	C<undef>.
		593
		594	The flags are a combination of the following constants, ORed together (the
		595	flags will also be passed to the callback, possibly modified):
		596
		597	=over 4
		598
		599	=item IO::AIO::READDIR_DENTS
		600
		601	When this flag is off, then the callback gets an arrayref with of names
		602	only (as with C<aio_readdir>), otherwise it gets an arrayref with
		603	C<[$name, $type, $inode]> arrayrefs, each describing a single directory
		604	entry in more detail.
		605
		606	C<$name> is the name of the entry.
		607
		608	C<$type> is one of the C<IO::AIO::DT_xxx> constants:
		609
		610	C<IO::AIO::DT_UNKNOWN>, C<IO::AIO::DT_FIFO>, C<IO::AIO::DT_CHR>, C<IO::AIO::DT_DIR>,
		611	C<IO::AIO::DT_BLK>, C<IO::AIO::DT_REG>, C<IO::AIO::DT_LNK>, C<IO::AIO::DT_SOCK>,
		612	C<IO::AIO::DT_WHT>.
		613
		614	C<IO::AIO::DT_UNKNOWN> means just that: readdir does not know. If you need to
		615	know, you have to run stat yourself. Also, for speed reasons, the C<$type>
		616	scalars are read-only: you can not modify them.
		617
		618	C<$inode> is the inode number (which might not be exact on systems with 64
		619	bit inode numbers and 32 bit perls). This field has unspecified content on
		620	systems that do not deliver the inode information.
		621
		622	=item IO::AIO::READDIR_DIRS_FIRST
		623
		624	When this flag is set, then the names will be returned in an order where
		625	likely directories come first. This is useful when you need to quickly
		626	find directories, or you want to find all directories while avoiding to
		627	stat() each entry.
		628
		629	If the system returns type information in readdir, then this is used
		630	to find directories directly. Otherwise, likely directories are files
		631	beginning with ".", or otherwise files with no dots, of which files with
		632	short names are tried first.
		633
		634	=item IO::AIO::READDIR_STAT_ORDER
		635
		636	When this flag is set, then the names will be returned in an order
		637	suitable for stat()'ing each one. That is, when you plan to stat()
		638	all files in the given directory, then the returned order will likely
		639	be fastest.
		640
		641	If both this flag and C<IO::AIO::READDIR_DIRS_FIRST> are specified, then
		642	the likely dirs come first, resulting in a less optimal stat order.
		643
		644	=item IO::AIO::READDIR_FOUND_UNKNOWN
		645
		646	This flag should not be set when calling C<aio_readdirx>. Instead, it
		647	is being set by C<aio_readdirx>, when any of the C<$type>'s found were
		648	C<IO::AIO::DT_UNKNOWN>. The absense of this flag therefore indicates that all
		649	C<$type>'s are known, which can be used to speed up some algorithms.
		650
		651	=back
		652
		653
		654	=item aio_load $path, $data, $callback->($status)
		655
		656	This is a composite request that tries to fully load the given file into
		657	memory. Status is the same as with aio_read.
		658
		659	=cut
		660
		661	sub aio_load($$;$) {
		662	my ($path, undef, $cb) = @_;
		663	my $data = \$_[1];
		664
		665	my $pri = aioreq_pri;
		666	my $grp = aio_group $cb;
		667
		668	aioreq_pri $pri;
		669	add $grp aio_open $path, O_RDONLY, 0, sub {
		670	my $fh = shift
		671	or return $grp->result (-1);
		672
		673	aioreq_pri $pri;
		674	add $grp aio_read $fh, 0, (-s $fh), $$data, 0, sub {
		675	$grp->result ($_[0]);
		676	};
		677	};
		678
		679	$grp
		680	}
447		681
448	=item aio_copy $srcpath, $dstpath, $callback->($status)	682	=item aio_copy $srcpath, $dstpath, $callback->($status)
449		683
450	Try to copy the I<file> (directories not supported as either source or	684	Try to copy the I<file> (directories not supported as either source or
451	destination) from C<$srcpath> to C<$dstpath> and call the callback with	685	destination) from C<$srcpath> to C<$dstpath> and call the callback with
452	the C<0> (error) or C<-1> ok.	686	a status of C<0> (ok) or C<-1> (error, see C<$!>).
453		687
454	This is a composite request that it creates the destination file with	688	This is a composite request that creates the destination file with
455	mode 0200 and copies the contents of the source file into it using	689	mode 0200 and copies the contents of the source file into it using
456	C<aio_sendfile>, followed by restoring atime, mtime, access mode and	690	C<aio_sendfile>, followed by restoring atime, mtime, access mode and
457	uid/gid, in that order.	691	uid/gid, in that order.
458		692
459	If an error occurs, the partial destination file will be unlinked, if	693	If an error occurs, the partial destination file will be unlinked, if
…		…
469	my $grp = aio_group $cb;	703	my $grp = aio_group $cb;
470		704
471	aioreq_pri $pri;	705	aioreq_pri $pri;
472	add $grp aio_open $src, O_RDONLY, 0, sub {	706	add $grp aio_open $src, O_RDONLY, 0, sub {
473	if (my $src_fh = $_[0]) {	707	if (my $src_fh = $_[0]) {
474	my @stat = stat $src_fh;	708	my @stat = stat $src_fh; # hmm, might block over nfs?
475		709
476	aioreq_pri $pri;	710	aioreq_pri $pri;
477	add $grp aio_open $dst, O_CREAT \| O_WRONLY \| O_TRUNC, 0200, sub {	711	add $grp aio_open $dst, O_CREAT \| O_WRONLY \| O_TRUNC, 0200, sub {
478	if (my $dst_fh = $_[0]) {	712	if (my $dst_fh = $_[0]) {
479	aioreq_pri $pri;	713	aioreq_pri $pri;
480	add $grp aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub {	714	add $grp aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub {
481	if ($_[0] == $stat[7]) {	715	if ($_[0] == $stat[7]) {
482	$grp->result (0);	716	$grp->result (0);
483	close $src_fh;	717	close $src_fh;
484		718
485	# those should not normally block. should. should.	719	my $ch = sub {
		720	aioreq_pri $pri;
		721	add $grp aio_chmod $dst_fh, $stat[2] & 07777, sub {
		722	aioreq_pri $pri;
		723	add $grp aio_chown $dst_fh, $stat[4], $stat[5], sub {
		724	aioreq_pri $pri;
		725	add $grp aio_close $dst_fh;
		726	}
		727	};
		728	};
		729
		730	aioreq_pri $pri;
		731	add $grp aio_utime $dst_fh, $stat[8], $stat[9], sub {
		732	if ($_[0] < 0 && $! == ENOSYS) {
		733	aioreq_pri $pri;
486	utime $stat[8], $stat[9], $dst;	734	add $grp aio_utime $dst, $stat[8], $stat[9], $ch;
487	chmod $stat[2] & 07777, $dst_fh;	735	} else {
488	chown $stat[4], $stat[5], $dst_fh;	736	$ch->();
		737	}
489	close $dst_fh;	738	};
490	} else {	739	} else {
491	$grp->result (-1);	740	$grp->result (-1);
492	close $src_fh;	741	close $src_fh;
493	close $dst_fh;	742	close $dst_fh;
494		743
…		…
511		760
512	=item aio_move $srcpath, $dstpath, $callback->($status)	761	=item aio_move $srcpath, $dstpath, $callback->($status)
513		762
514	Try to move the I<file> (directories not supported as either source or	763	Try to move the I<file> (directories not supported as either source or
515	destination) from C<$srcpath> to C<$dstpath> and call the callback with	764	destination) from C<$srcpath> to C<$dstpath> and call the callback with
516	the C<0> (error) or C<-1> ok.	765	a status of C<0> (ok) or C<-1> (error, see C<$!>).
517		766
518	This is a composite request that tries to rename(2) the file first. If	767	This is a composite request that tries to rename(2) the file first; if
519	rename files with C<EXDEV>, it copies the file with C<aio_copy> and, if	768	rename fails with C<EXDEV>, it copies the file with C<aio_copy> and, if
520	that is successful, unlinking the C<$srcpath>.	769	that is successful, unlinks the C<$srcpath>.
521		770
522	=cut	771	=cut
523		772
524	sub aio_move($$;$) {	773	sub aio_move($$;$) {
525	my ($src, $dst, $cb) = @_;	774	my ($src, $dst, $cb) = @_;
…		…
572		821
573	Implementation notes.	822	Implementation notes.
574		823
575	The C<aio_readdir> cannot be avoided, but C<stat()>'ing every entry can.	824	The C<aio_readdir> cannot be avoided, but C<stat()>'ing every entry can.
576		825
		826	If readdir returns file type information, then this is used directly to
		827	find directories.
		828
577	After reading the directory, the modification time, size etc. of the	829	Otherwise, after reading the directory, the modification time, size etc.
578	directory before and after the readdir is checked, and if they match (and	830	of the directory before and after the readdir is checked, and if they
579	isn't the current time), the link count will be used to decide how many	831	match (and isn't the current time), the link count will be used to decide
580	entries are directories (if >= 2). Otherwise, no knowledge of the number	832	how many entries are directories (if >= 2). Otherwise, no knowledge of the
581	of subdirectories will be assumed.	833	number of subdirectories will be assumed.
582		834
583	Then entries will be sorted into likely directories (everything without	835	Then entries will be sorted into likely directories a non-initial dot
584	a non-initial dot currently) and likely non-directories (everything	836	currently) and likely non-directories (see C<aio_readdirx>). Then every
585	else). Then every entry plus an appended C</.> will be C<stat>'ed,	837	entry plus an appended C</.> will be C<stat>'ed, likely directories first,
586	likely directories first. If that succeeds, it assumes that the entry	838	in order of their inode numbers. If that succeeds, it assumes that the
587	is a directory or a symlink to directory (which will be checked	839	entry is a directory or a symlink to directory (which will be checked
588	seperately). This is often faster than stat'ing the entry itself because	840	seperately). This is often faster than stat'ing the entry itself because
589	filesystems might detect the type of the entry without reading the inode	841	filesystems might detect the type of the entry without reading the inode
590	data (e.g. ext2fs filetype feature).	842	data (e.g. ext2fs filetype feature), even on systems that cannot return
		843	the filetype information on readdir.
591		844
592	If the known number of directories (link count - 2) has been reached, the	845	If the known number of directories (link count - 2) has been reached, the
593	rest of the entries is assumed to be non-directories.	846	rest of the entries is assumed to be non-directories.
594		847
595	This only works with certainty on POSIX (= UNIX) filesystems, which	848	This only works with certainty on POSIX (= UNIX) filesystems, which
…		…
599	as those tend to return 0 or 1 as link counts, which disables the	852	as those tend to return 0 or 1 as link counts, which disables the
600	directory counting heuristic.	853	directory counting heuristic.
601		854
602	=cut	855	=cut
603		856
604	sub aio_scandir($$$) {	857	sub aio_scandir($$;$) {
605	my ($path, $maxreq, $cb) = @_;	858	my ($path, $maxreq, $cb) = @_;
606		859
607	my $pri = aioreq_pri;	860	my $pri = aioreq_pri;
608		861
609	my $grp = aio_group $cb;	862	my $grp = aio_group $cb;
…		…
617	my $now = time;	870	my $now = time;
618	my $hash1 = join ":", (stat _)[0,1,3,7,9];	871	my $hash1 = join ":", (stat _)[0,1,3,7,9];
619		872
620	# read the directory entries	873	# read the directory entries
621	aioreq_pri $pri;	874	aioreq_pri $pri;
622	add $grp aio_readdir $path, sub {	875	add $grp aio_readdirx $path, READDIR_DIRS_FIRST, sub {
623	my $entries = shift	876	my $entries = shift
624	or return $grp->result ();	877	or return $grp->result ();
625		878
626	# stat the dir another time	879	# stat the dir another time
627	aioreq_pri $pri;	880	aioreq_pri $pri;
…		…
633	# take the slow route if anything looks fishy	886	# take the slow route if anything looks fishy
634	if ($hash1 ne $hash2 or (stat _)[9] == $now) {	887	if ($hash1 ne $hash2 or (stat _)[9] == $now) {
635	$ndirs = -1;	888	$ndirs = -1;
636	} else {	889	} else {
637	# if nlink == 2, we are finished	890	# if nlink == 2, we are finished
638	# on non-posix-fs's, we rely on nlink < 2	891	# for non-posix-fs's, we rely on nlink < 2
639	$ndirs = (stat _)[3] - 2	892	$ndirs = (stat _)[3] - 2
640	or return $grp->result ([], $entries);	893	or return $grp->result ([], $entries);
641	}	894	}
642		895
643	# sort into likely dirs and likely nondirs
644	# dirs == files without ".", short entries first
645	$entries = [map $_->[0],
646	sort { $b->[1] cmp $a->[1] }
647	map [$_, sprintf "%s%04d", (/.\./ ? "1" : "0"), length],
648	@$entries];
649
650	my (@dirs, @nondirs);	896	my (@dirs, @nondirs);
651		897
652	my $statgrp = add $grp aio_group sub {	898	my $statgrp = add $grp aio_group sub {
653	$grp->result (\@dirs, \@nondirs);	899	$grp->result (\@dirs, \@nondirs);
654	};	900	};
655		901
656	limit $statgrp $maxreq;	902	limit $statgrp $maxreq;
657	feed $statgrp sub {	903	feed $statgrp sub {
658	return unless @$entries;	904	return unless @$entries;
659	my $entry = pop @$entries;	905	my $entry = shift @$entries;
660		906
661	aioreq_pri $pri;	907	aioreq_pri $pri;
662	add $statgrp aio_stat "$path/$entry/.", sub {	908	add $statgrp aio_stat "$path/$entry/.", sub {
663	if ($_[0] < 0) {	909	if ($_[0] < 0) {
664	push @nondirs, $entry;	910	push @nondirs, $entry;
…		…
685	};	931	};
686		932
687	$grp	933	$grp
688	}	934	}
689		935
		936	=item aio_rmtree $path, $callback->($status)
		937
		938	Delete a directory tree starting (and including) C<$path>, return the
		939	status of the final C<rmdir> only. This is a composite request that
		940	uses C<aio_scandir> to recurse into and rmdir directories, and unlink
		941	everything else.
		942
		943	=cut
		944
		945	sub aio_rmtree;
		946	sub aio_rmtree($;$) {
		947	my ($path, $cb) = @_;
		948
		949	my $pri = aioreq_pri;
		950	my $grp = aio_group $cb;
		951
		952	aioreq_pri $pri;
		953	add $grp aio_scandir $path, 0, sub {
		954	my ($dirs, $nondirs) = @_;
		955
		956	my $dirgrp = aio_group sub {
		957	add $grp aio_rmdir $path, sub {
		958	$grp->result ($_[0]);
		959	};
		960	};
		961
		962	(aioreq_pri $pri), add $dirgrp aio_rmtree "$path/$_" for @$dirs;
		963	(aioreq_pri $pri), add $dirgrp aio_unlink "$path/$_" for @$nondirs;
		964
		965	add $grp $dirgrp;
		966	};
		967
		968	$grp
		969	}
		970
		971	=item aio_sync $callback->($status)
		972
		973	Asynchronously call sync and call the callback when finished.
		974
690	=item aio_fsync $fh, $callback->($status)	975	=item aio_fsync $fh, $callback->($status)
691		976
692	Asynchronously call fsync on the given filehandle and call the callback	977	Asynchronously call fsync on the given filehandle and call the callback
693	with the fsync result code.	978	with the fsync result code.
694		979
…		…
697	Asynchronously call fdatasync on the given filehandle and call the	982	Asynchronously call fdatasync on the given filehandle and call the
698	callback with the fdatasync result code.	983	callback with the fdatasync result code.
699		984
700	If this call isn't available because your OS lacks it or it couldn't be	985	If this call isn't available because your OS lacks it or it couldn't be
701	detected, it will be emulated by calling C<fsync> instead.	986	detected, it will be emulated by calling C<fsync> instead.
		987
		988	=item aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status)
		989
		990	Sync the data portion of the file specified by C<$offset> and C<$length>
		991	to disk (but NOT the metadata), by calling the Linux-specific
		992	sync_file_range call. If sync_file_range is not available or it returns
		993	ENOSYS, then fdatasync or fsync is being substituted.
		994
		995	C<$flags> can be a combination of C<IO::AIO::SYNC_FILE_RANGE_WAIT_BEFORE>,
		996	C<IO::AIO::SYNC_FILE_RANGE_WRITE> and
		997	C<IO::AIO::SYNC_FILE_RANGE_WAIT_AFTER>: refer to the sync_file_range
		998	manpage for details.
		999
		1000	=item aio_pathsync $path, $callback->($status)
		1001
		1002	This request tries to open, fsync and close the given path. This is a
		1003	composite request intended to sync directories after directory operations
		1004	(E.g. rename). This might not work on all operating systems or have any
		1005	specific effect, but usually it makes sure that directory changes get
		1006	written to disc. It works for anything that can be opened for read-only,
		1007	not just directories.
		1008
		1009	Future versions of this function might fall back to other methods when
		1010	C<fsync> on the directory fails (such as calling C<sync>).
		1011
		1012	Passes C<0> when everything went ok, and C<-1> on error.
		1013
		1014	=cut
		1015
		1016	sub aio_pathsync($;$) {
		1017	my ($path, $cb) = @_;
		1018
		1019	my $pri = aioreq_pri;
		1020	my $grp = aio_group $cb;
		1021
		1022	aioreq_pri $pri;
		1023	add $grp aio_open $path, O_RDONLY, 0, sub {
		1024	my ($fh) = @_;
		1025	if ($fh) {
		1026	aioreq_pri $pri;
		1027	add $grp aio_fsync $fh, sub {
		1028	$grp->result ($_[0]);
		1029
		1030	aioreq_pri $pri;
		1031	add $grp aio_close $fh;
		1032	};
		1033	} else {
		1034	$grp->result (-1);
		1035	}
		1036	};
		1037
		1038	$grp
		1039	}
		1040
		1041	=item aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
		1042
		1043	This is a rather advanced IO::AIO call, which only works on mmap(2)ed
		1044	scalars (see the L<Sys::Mmap> or L<Mmap> modules for details on this, note
		1045	that the scalar must only be modified in-place while an aio operation is
		1046	pending on it).
		1047
		1048	It calls the C<msync> function of your OS, if available, with the memory
		1049	area starting at C<$offset> in the string and ending C<$length> bytes
		1050	later. If C<$length> is negative, counts from the end, and if C<$length>
		1051	is C<undef>, then it goes till the end of the string. The flags can be
		1052	a combination of C<IO::AIO::MS_ASYNC>, C<IO::AIO::MS_INVALIDATE> and
		1053	C<IO::AIO::MS_SYNC>.
		1054
		1055	=item aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
		1056
		1057	This is a rather advanced IO::AIO call, which works best on mmap(2)ed
		1058	scalars.
		1059
		1060	It touches (reads or writes) all memory pages in the specified
		1061	range inside the scalar. All caveats and parameters are the same
		1062	as for C<aio_msync>, above, except for flags, which must be either
		1063	C<0> (which reads all pages and ensures they are instantiated) or
		1064	C<IO::AIO::MT_MODIFY>, which modifies the memory page s(by reading and
		1065	writing an octet from it, which dirties the page).
702		1066
703	=item aio_group $callback->(...)	1067	=item aio_group $callback->(...)
704		1068
705	This is a very special aio request: Instead of doing something, it is a	1069	This is a very special aio request: Instead of doing something, it is a
706	container for other aio requests, which is useful if you want to bundle	1070	container for other aio requests, which is useful if you want to bundle
…		…
756	=item cancel $req	1120	=item cancel $req
757		1121
758	Cancels the request, if possible. Has the effect of skipping execution	1122	Cancels the request, if possible. Has the effect of skipping execution
759	when entering the B<execute> state and skipping calling the callback when	1123	when entering the B<execute> state and skipping calling the callback when
760	entering the the B<result> state, but will leave the request otherwise	1124	entering the the B<result> state, but will leave the request otherwise
761	untouched. That means that requests that currently execute will not be	1125	untouched (with the exception of readdir). That means that requests that
762	stopped and resources held by the request will not be freed prematurely.	1126	currently execute will not be stopped and resources held by the request
		1127	will not be freed prematurely.
763		1128
764	=item cb $req $callback->(...)	1129	=item cb $req $callback->(...)
765		1130
766	Replace (or simply set) the callback registered to the request.	1131	Replace (or simply set) the callback registered to the request.
767		1132
…		…
818	Their lifetime, simplified, looks like this: when they are empty, they	1183	Their lifetime, simplified, looks like this: when they are empty, they
819	will finish very quickly. If they contain only requests that are in the	1184	will finish very quickly. If they contain only requests that are in the
820	C<done> state, they will also finish. Otherwise they will continue to	1185	C<done> state, they will also finish. Otherwise they will continue to
821	exist.	1186	exist.
822		1187
823	That means after creating a group you have some time to add requests. And	1188	That means after creating a group you have some time to add requests
824	in the callbacks of those requests, you can add further requests to the	1189	(precisely before the callback has been invoked, which is only done within
825	group. And only when all those requests have finished will the the group	1190	the C<poll_cb>). And in the callbacks of those requests, you can add
826	itself finish.	1191	further requests to the group. And only when all those requests have
		1192	finished will the the group itself finish.
827		1193
828	=over 4	1194	=over 4
829		1195
830	=item add $grp ...	1196	=item add $grp ...
831		1197
…		…
840	=item $grp->cancel_subs	1206	=item $grp->cancel_subs
841		1207
842	Cancel all subrequests and clears any feeder, but not the group request	1208	Cancel all subrequests and clears any feeder, but not the group request
843	itself. Useful when you queued a lot of events but got a result early.	1209	itself. Useful when you queued a lot of events but got a result early.
844		1210
		1211	The group request will finish normally (you cannot add requests to the
		1212	group).
		1213
845	=item $grp->result (...)	1214	=item $grp->result (...)
846		1215
847	Set the result value(s) that will be passed to the group callback when all	1216	Set the result value(s) that will be passed to the group callback when all
848	subrequests have finished and set thre groups errno to the current value	1217	subrequests have finished and set the groups errno to the current value
849	of errno (just like calling C<errno> without an error number). By default,	1218	of errno (just like calling C<errno> without an error number). By default,
850	no argument will be passed and errno is zero.	1219	no argument will be passed and errno is zero.
851		1220
852	=item $grp->errno ([$errno])	1221	=item $grp->errno ([$errno])
853		1222
…		…
864	=item feed $grp $callback->($grp)	1233	=item feed $grp $callback->($grp)
865		1234
866	Sets a feeder/generator on this group: every group can have an attached	1235	Sets a feeder/generator on this group: every group can have an attached
867	generator that generates requests if idle. The idea behind this is that,	1236	generator that generates requests if idle. The idea behind this is that,
868	although you could just queue as many requests as you want in a group,	1237	although you could just queue as many requests as you want in a group,
869	this might starve other requests for a potentially long time. For	1238	this might starve other requests for a potentially long time. For example,
870	example, C<aio_scandir> might generate hundreds of thousands C<aio_stat>	1239	C<aio_scandir> might generate hundreds of thousands C<aio_stat> requests,
871	requests, delaying any later requests for a long time.	1240	delaying any later requests for a long time.
872		1241
873	To avoid this, and allow incremental generation of requests, you can	1242	To avoid this, and allow incremental generation of requests, you can
874	instead a group and set a feeder on it that generates those requests. The	1243	instead a group and set a feeder on it that generates those requests. The
875	feed callback will be called whenever there are few enough (see C<limit>,	1244	feed callback will be called whenever there are few enough (see C<limit>,
876	below) requests active in the group itself and is expected to queue more	1245	below) requests active in the group itself and is expected to queue more
…		…
880	not impose any limits).	1249	not impose any limits).
881		1250
882	If the feed does not queue more requests when called, it will be	1251	If the feed does not queue more requests when called, it will be
883	automatically removed from the group.	1252	automatically removed from the group.
884		1253
885	If the feed limit is C<0>, it will be set to C<2> automatically.	1254	If the feed limit is C<0> when this method is called, it will be set to
		1255	C<2> automatically.
886		1256
887	Example:	1257	Example:
888		1258
889	# stat all files in @files, but only ever use four aio requests concurrently:	1259	# stat all files in @files, but only ever use four aio requests concurrently:
890		1260
…		…
902	Sets the feeder limit for the group: The feeder will be called whenever	1272	Sets the feeder limit for the group: The feeder will be called whenever
903	the group contains less than this many requests.	1273	the group contains less than this many requests.
904		1274
905	Setting the limit to C<0> will pause the feeding process.	1275	Setting the limit to C<0> will pause the feeding process.
906		1276
		1277	The default value for the limit is C<0>, but note that setting a feeder
		1278	automatically bumps it up to C<2>.
		1279
907	=back	1280	=back
908		1281
909	=head2 SUPPORT FUNCTIONS	1282	=head2 SUPPORT FUNCTIONS
910		1283
911	=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION	1284	=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION
…		…
913	=over 4	1286	=over 4
914		1287
915	=item $fileno = IO::AIO::poll_fileno	1288	=item $fileno = IO::AIO::poll_fileno
916		1289
917	Return the I<request result pipe file descriptor>. This filehandle must be	1290	Return the I<request result pipe file descriptor>. This filehandle must be
918	polled for reading by some mechanism outside this module (e.g. Event or	1291	polled for reading by some mechanism outside this module (e.g. EV, Glib,
919	select, see below or the SYNOPSIS). If the pipe becomes readable you have	1292	select and so on, see below or the SYNOPSIS). If the pipe becomes readable
920	to call C<poll_cb> to check the results.	1293	you have to call C<poll_cb> to check the results.
921		1294
922	See C<poll_cb> for an example.	1295	See C<poll_cb> for an example.
923		1296
924	=item IO::AIO::poll_cb	1297	=item IO::AIO::poll_cb
925		1298
926	Process some outstanding events on the result pipe. You have to call this	1299	Process some outstanding events on the result pipe. You have to call this
927	regularly. Returns the number of events processed. Returns immediately	1300	regularly. Returns C<0> if all events could be processed, or C<-1> if it
		1301	returned earlier for whatever reason. Returns immediately when no events
928	when no events are outstanding. The amount of events processed depends on	1302	are outstanding. The amount of events processed depends on the settings of
929	the settings of C<IO::AIO::max_poll_req> and C<IO::AIO::max_poll_time>.	1303	C<IO::AIO::max_poll_req> and C<IO::AIO::max_poll_time>.
930		1304
931	If not all requests were processed for whatever reason, the filehandle	1305	If not all requests were processed for whatever reason, the filehandle
932	will still be ready when C<poll_cb> returns.	1306	will still be ready when C<poll_cb> returns, so normally you don't have to
		1307	do anything special to have it called later.
933		1308
934	Example: Install an Event watcher that automatically calls	1309	Example: Install an Event watcher that automatically calls
935	IO::AIO::poll_cb with high priority:	1310	IO::AIO::poll_cb with high priority (more examples can be found in the
		1311	SYNOPSIS section, at the top of this document):
936		1312
937	Event->io (fd => IO::AIO::poll_fileno,	1313	Event->io (fd => IO::AIO::poll_fileno,
938	poll => 'r', async => 1,	1314	poll => 'r', async => 1,
939	cb => \&IO::AIO::poll_cb);	1315	cb => \&IO::AIO::poll_cb);
940		1316
…		…
971	poll => 'r', nice => 1,	1347	poll => 'r', nice => 1,
972	cb => &IO::AIO::poll_cb);	1348	cb => &IO::AIO::poll_cb);
973		1349
974	=item IO::AIO::poll_wait	1350	=item IO::AIO::poll_wait
975		1351
		1352	If there are any outstanding requests and none of them in the result
976	Wait till the result filehandle becomes ready for reading (simply does a	1353	phase, wait till the result filehandle becomes ready for reading (simply
977	C<select> on the filehandle. This is useful if you want to synchronously	1354	does a C<select> on the filehandle. This is useful if you want to
978	wait for some requests to finish).	1355	synchronously wait for some requests to finish).
979		1356
980	See C<nreqs> for an example.	1357	See C<nreqs> for an example.
981		1358
982	=item IO::AIO::poll	1359	=item IO::AIO::poll
983		1360
984	Waits until some requests have been handled.	1361	Waits until some requests have been handled.
985		1362
		1363	Returns the number of requests processed, but is otherwise strictly
986	Strictly equivalent to:	1364	equivalent to:
987		1365
988	IO::AIO::poll_wait, IO::AIO::poll_cb	1366	IO::AIO::poll_wait, IO::AIO::poll_cb
989	if IO::AIO::nreqs;
990		1367
991	=item IO::AIO::flush	1368	=item IO::AIO::flush
992		1369
993	Wait till all outstanding AIO requests have been handled.	1370	Wait till all outstanding AIO requests have been handled.
994		1371
995	Strictly equivalent to:	1372	Strictly equivalent to:
996		1373
997	IO::AIO::poll_wait, IO::AIO::poll_cb	1374	IO::AIO::poll_wait, IO::AIO::poll_cb
998	while IO::AIO::nreqs;	1375	while IO::AIO::nreqs;
999		1376
		1377	=back
		1378
1000	=head3 CONTROLLING THE NUMBER OF THREADS	1379	=head3 CONTROLLING THE NUMBER OF THREADS
		1380
		1381	=over
1001		1382
1002	=item IO::AIO::min_parallel $nthreads	1383	=item IO::AIO::min_parallel $nthreads
1003		1384
1004	Set the minimum number of AIO threads to C<$nthreads>. The current	1385	Set the minimum number of AIO threads to C<$nthreads>. The current
1005	default is C<8>, which means eight asynchronous operations can execute	1386	default is C<8>, which means eight asynchronous operations can execute
…		…
1046		1427
1047	The default is probably ok in most situations, especially if thread	1428	The default is probably ok in most situations, especially if thread
1048	creation is fast. If thread creation is very slow on your system you might	1429	creation is fast. If thread creation is very slow on your system you might
1049	want to use larger values.	1430	want to use larger values.
1050		1431
1051	=item $oldmaxreqs = IO::AIO::max_outstanding $maxreqs	1432	=item IO::AIO::max_outstanding $maxreqs
1052		1433
1053	This is a very bad function to use in interactive programs because it	1434	This is a very bad function to use in interactive programs because it
1054	blocks, and a bad way to reduce concurrency because it is inexact: Better	1435	blocks, and a bad way to reduce concurrency because it is inexact: Better
1055	use an C<aio_group> together with a feed callback.	1436	use an C<aio_group> together with a feed callback.
1056		1437
1057	Sets the maximum number of outstanding requests to C<$nreqs>. If you	1438	Sets the maximum number of outstanding requests to C<$nreqs>. If you
1058	to queue up more than this number of requests, the next call to the	1439	do queue up more than this number of requests, the next call to the
1059	C<poll_cb> (and C<poll_some> and other functions calling C<poll_cb>)	1440	C<poll_cb> (and C<poll_some> and other functions calling C<poll_cb>)
1060	function will block until the limit is no longer exceeded.	1441	function will block until the limit is no longer exceeded.
1061		1442
1062	The default value is very large, so there is no practical limit on the	1443	The default value is very large, so there is no practical limit on the
1063	number of outstanding requests.	1444	number of outstanding requests.
1064		1445
1065	You can still queue as many requests as you want. Therefore,	1446	You can still queue as many requests as you want. Therefore,
1066	C<max_oustsanding> is mainly useful in simple scripts (with low values) or	1447	C<max_outstanding> is mainly useful in simple scripts (with low values) or
1067	as a stop gap to shield against fatal memory overflow (with large values).	1448	as a stop gap to shield against fatal memory overflow (with large values).
1068		1449
		1450	=back
		1451
1069	=head3 STATISTICAL INFORMATION	1452	=head3 STATISTICAL INFORMATION
		1453
		1454	=over
1070		1455
1071	=item IO::AIO::nreqs	1456	=item IO::AIO::nreqs
1072		1457
1073	Returns the number of requests currently in the ready, execute or pending	1458	Returns the number of requests currently in the ready, execute or pending
1074	states (i.e. for which their callback has not been invoked yet).	1459	states (i.e. for which their callback has not been invoked yet).
…		…
1088	Returns the number of requests currently in the pending state (executed,	1473	Returns the number of requests currently in the pending state (executed,
1089	but not yet processed by poll_cb).	1474	but not yet processed by poll_cb).
1090		1475
1091	=back	1476	=back
1092		1477
		1478	=head3 MISCELLANEOUS FUNCTIONS
		1479
		1480	IO::AIO implements some functions that might be useful, but are not
		1481	asynchronous.
		1482
		1483	=over 4
		1484
		1485	=item IO::AIO::sendfile $ofh, $ifh, $offset, $count
		1486
		1487	Calls the C<eio_sendfile_sync> function, which is like C<aio_sendfile>,
		1488	but is blocking (this makes most sense if you know the input data is
		1489	likely cached already and the output filehandle is set to non-blocking
		1490	operations).
		1491
		1492	Returns the number of bytes copied, or C<-1> on error.
		1493
		1494	=item IO::AIO::fadvise $fh, $offset, $len, $advice
		1495
		1496	Simply calls the C<posix_fadvise> function (see it's
		1497	manpage for details). The following advice constants are
		1498	avaiable: C<IO::AIO::FADV_NORMAL>, C<IO::AIO::FADV_SEQUENTIAL>,
		1499	C<IO::AIO::FADV_RANDOM>, C<IO::AIO::FADV_NOREUSE>,
		1500	C<IO::AIO::FADV_WILLNEED>, C<IO::AIO::FADV_DONTNEED>.
		1501
		1502	On systems that do not implement C<posix_fadvise>, this function returns
		1503	ENOSYS, otherwise the return value of C<posix_fadvise>.
		1504
		1505	=back
		1506
1093	=cut	1507	=cut
1094		1508
1095	# support function to convert a fd into a perl filehandle
1096	sub _fd2fh {
1097	return undef if $_[0] < 0;
1098
1099	# try to generate nice filehandles
1100	my $sym = "IO::AIO::fd#$_[0]";
1101	local *$sym;
1102
1103	open *$sym, "+<&=$_[0]" # usually works under any unix
1104	or open *$sym, "<&=$_[0]" # cygwin needs this
1105	or open *$sym, ">&=$_[0]" # or this
1106	or return undef;
1107
1108	*$sym
1109	}
1110
1111	min_parallel 8;	1509	min_parallel 8;
1112		1510
1113	END {	1511	END { flush }
1114	min_parallel 1;
1115	flush;
1116	};
1117		1512
1118	1;	1513	1;
1119		1514
1120	=head2 FORK BEHAVIOUR	1515	=head2 FORK BEHAVIOUR
1121		1516
…		…
1141	bytes of memory. In addition, stat requests need a stat buffer (possibly	1536	bytes of memory. In addition, stat requests need a stat buffer (possibly
1142	a few hundred bytes), readdir requires a result buffer and so on. Perl	1537	a few hundred bytes), readdir requires a result buffer and so on. Perl
1143	scalars and other data passed into aio requests will also be locked and	1538	scalars and other data passed into aio requests will also be locked and
1144	will consume memory till the request has entered the done state.	1539	will consume memory till the request has entered the done state.
1145		1540
1146	This is now awfully much, so queuing lots of requests is not usually a	1541	This is not awfully much, so queuing lots of requests is not usually a
1147	problem.	1542	problem.
1148		1543
1149	Per-thread usage:	1544	Per-thread usage:
1150		1545
1151	In the execution phase, some aio requests require more memory for	1546	In the execution phase, some aio requests require more memory for
…		…
1156		1551
1157	Known bugs will be fixed in the next release.	1552	Known bugs will be fixed in the next release.
1158		1553
1159	=head1 SEE ALSO	1554	=head1 SEE ALSO
1160		1555
1161	L<Coro::AIO>.	1556	L<AnyEvent::AIO> for easy integration into event loops, L<Coro::AIO> for a
		1557	more natural syntax.
1162		1558
1163	=head1 AUTHOR	1559	=head1 AUTHOR
1164		1560
1165	Marc Lehmann <schmorp@schmorp.de>	1561	Marc Lehmann <schmorp@schmorp.de>
1166	http://home.schmorp.de/	1562	http://home.schmorp.de/

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Comparing IO-AIO/AIO.pm (file contents): Revision 1.91 by root, Mon Oct 30 23:30:29 2006 UTC vs. Revision 1.173 by root, Thu Jan 7 20:25:57 2010 UTC

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Comparing IO-AIO/AIO.pm (file contents):
Revision 1.91 by root, Mon Oct 30 23:30:29 2006 UTC vs.
Revision 1.173 by root, Thu Jan 7 20:25:57 2010 UTC