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

Comparing IO-AIO/AIO.pm (file contents):
Revision 1.171 by root, Sat Jan 2 14:24:32 2010 UTC vs.
Revision 1.226 by root, Mon May 28 17:00:19 2012 UTC

…		…
4		4
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", IO::AIO::O_RDONLY, 0, sub {
10	my $fh = shift	10	my $fh = shift
11	or die "/etc/passwd: $!";	11	or die "/etc/passwd: $!";
12	...	12	...
13	};	13	};
14		14
…		…
25	my $req = aio_unlink "/tmp/file", sub { };	25	my $req = aio_unlink "/tmp/file", sub { };
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
31	# AnyEvent integration (EV, Event, Glib, Tk, POE, urxvt, pureperl...)
32	use AnyEvent::AIO;
33
34	# EV integration
35	my $aio_w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb;
36
37	# Event integration
38	Event->io (fd => IO::AIO::poll_fileno,
39	poll => 'r',
40	cb => \&IO::AIO::poll_cb);
41
42	# Glib/Gtk2 integration
43	add_watch Glib::IO IO::AIO::poll_fileno,
44	in => sub { IO::AIO::poll_cb; 1 };
45
46	# Tk integration
47	Tk::Event::IO->fileevent (IO::AIO::poll_fileno, "",
48	readable => \&IO::AIO::poll_cb);
49
50	# Danga::Socket integration
51	Danga::Socket->AddOtherFds (IO::AIO::poll_fileno =>
52	\&IO::AIO::poll_cb);
53		30
54	=head1 DESCRIPTION	31	=head1 DESCRIPTION
55		32
56	This module implements asynchronous I/O using whatever means your	33	This module implements asynchronous I/O using whatever means your
57	operating system supports. It is implemented as an interface to C<libeio>	34	operating system supports. It is implemented as an interface to C<libeio>
…		…
99		76
100	# register the IO::AIO callback with EV	77	# register the IO::AIO callback with EV
101	my $aio_w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb;	78	my $aio_w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb;
102		79
103	# queue the request to open /etc/passwd	80	# queue the request to open /etc/passwd
104	aio_open "/etc/passwd", O_RDONLY, 0, sub {	81	aio_open "/etc/passwd", IO::AIO::O_RDONLY, 0, sub {
105	my $fh = shift	82	my $fh = shift
106	or die "error while opening: $!";	83	or die "error while opening: $!";
107		84
108	# stat'ing filehandles is generally non-blocking	85	# stat'ing filehandles is generally non-blocking
109	my $size = -s $fh;	86	my $size = -s $fh;
…		…
191	use common::sense;	168	use common::sense;
192		169
193	use base 'Exporter';	170	use base 'Exporter';
194		171
195	BEGIN {	172	BEGIN {
196	our $VERSION = '3.4';	173	our $VERSION = '4.15';
197		174
198	our @AIO_REQ = qw(aio_sendfile aio_read aio_write aio_open aio_close	175	our @AIO_REQ = qw(aio_sendfile aio_seek aio_read aio_write aio_open aio_close
199	aio_stat aio_lstat aio_unlink aio_rmdir aio_readdir aio_readdirx	176	aio_stat aio_lstat aio_unlink aio_rmdir aio_readdir aio_readdirx
200	aio_scandir aio_symlink aio_readlink aio_sync aio_fsync	177	aio_scandir aio_symlink aio_readlink aio_realpath aio_sync
201	aio_fdatasync aio_sync_file_range aio_pathsync aio_readahead	178	aio_fsync aio_syncfs aio_fdatasync aio_sync_file_range aio_fallocate
		179	aio_pathsync aio_readahead aio_fiemap
202	aio_rename aio_link aio_move aio_copy aio_group	180	aio_rename aio_link aio_move aio_copy aio_group
203	aio_nop aio_mknod aio_load aio_rmtree aio_mkdir aio_chown	181	aio_nop aio_mknod aio_load aio_rmtree aio_mkdir aio_chown
204	aio_chmod aio_utime aio_truncate	182	aio_chmod aio_utime aio_truncate
205	aio_msync aio_mtouch);	183	aio_msync aio_mtouch aio_mlock aio_mlockall
		184	aio_statvfs
		185	aio_wd);
206		186
207	our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice));	187	our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice));
208	our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush	188	our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush
209	min_parallel max_parallel max_idle	189	min_parallel max_parallel max_idle idle_timeout
210	nreqs nready npending nthreads	190	nreqs nready npending nthreads
211	max_poll_time max_poll_reqs	191	max_poll_time max_poll_reqs
212	sendfile fadvise);	192	sendfile fadvise madvise
		193	mmap munmap munlock munlockall);
213		194
214	push @AIO_REQ, qw(aio_busy); # not exported	195	push @AIO_REQ, qw(aio_busy); # not exported
215		196
216	@IO::AIO::GRP::ISA = 'IO::AIO::REQ';	197	@IO::AIO::GRP::ISA = 'IO::AIO::REQ';
217		198
…		…
219	XSLoader::load ("IO::AIO", $VERSION);	200	XSLoader::load ("IO::AIO", $VERSION);
220	}	201	}
221		202
222	=head1 FUNCTIONS	203	=head1 FUNCTIONS
223		204
224	=head2 AIO REQUEST FUNCTIONS	205	=head2 QUICK OVERVIEW
		206
		207	This section simply lists the prototypes of the most important functions
		208	for quick reference. See the following sections for function-by-function
		209	documentation.
		210
		211	aio_wd $pathname, $callback->($wd)
		212	aio_open $pathname, $flags, $mode, $callback->($fh)
		213	aio_close $fh, $callback->($status)
		214	aio_seek $fh,$offset,$whence, $callback->($offs)
		215	aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
		216	aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
		217	aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval)
		218	aio_readahead $fh,$offset,$length, $callback->($retval)
		219	aio_stat $fh_or_path, $callback->($status)
		220	aio_lstat $fh, $callback->($status)
		221	aio_statvfs $fh_or_path, $callback->($statvfs)
		222	aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
		223	aio_chown $fh_or_path, $uid, $gid, $callback->($status)
		224	aio_chmod $fh_or_path, $mode, $callback->($status)
		225	aio_truncate $fh_or_path, $offset, $callback->($status)
		226	aio_unlink $pathname, $callback->($status)
		227	aio_mknod $pathname, $mode, $dev, $callback->($status)
		228	aio_link $srcpath, $dstpath, $callback->($status)
		229	aio_symlink $srcpath, $dstpath, $callback->($status)
		230	aio_readlink $pathname, $callback->($link)
		231	aio_realpath $pathname, $callback->($link)
		232	aio_rename $srcpath, $dstpath, $callback->($status)
		233	aio_mkdir $pathname, $mode, $callback->($status)
		234	aio_rmdir $pathname, $callback->($status)
		235	aio_readdir $pathname, $callback->($entries)
		236	aio_readdirx $pathname, $flags, $callback->($entries, $flags)
		237	IO::AIO::READDIR_DENTS IO::AIO::READDIR_DIRS_FIRST
		238	IO::AIO::READDIR_STAT_ORDER IO::AIO::READDIR_FOUND_UNKNOWN
		239	aio_scandir $pathname, $maxreq, $callback->($dirs, $nondirs)
		240	aio_load $pathname, $data, $callback->($status)
		241	aio_copy $srcpath, $dstpath, $callback->($status)
		242	aio_move $srcpath, $dstpath, $callback->($status)
		243	aio_rmtree $pathname, $callback->($status)
		244	aio_sync $callback->($status)
		245	aio_syncfs $fh, $callback->($status)
		246	aio_fsync $fh, $callback->($status)
		247	aio_fdatasync $fh, $callback->($status)
		248	aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status)
		249	aio_pathsync $pathname, $callback->($status)
		250	aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
		251	aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
		252	aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status)
		253	aio_mlockall $flags, $callback->($status)
		254	aio_group $callback->(...)
		255	aio_nop $callback->()
		256
		257	$prev_pri = aioreq_pri [$pri]
		258	aioreq_nice $pri_adjust
		259
		260	IO::AIO::poll_wait
		261	IO::AIO::poll_cb
		262	IO::AIO::poll
		263	IO::AIO::flush
		264	IO::AIO::max_poll_reqs $nreqs
		265	IO::AIO::max_poll_time $seconds
		266	IO::AIO::min_parallel $nthreads
		267	IO::AIO::max_parallel $nthreads
		268	IO::AIO::max_idle $nthreads
		269	IO::AIO::idle_timeout $seconds
		270	IO::AIO::max_outstanding $maxreqs
		271	IO::AIO::nreqs
		272	IO::AIO::nready
		273	IO::AIO::npending
		274
		275	IO::AIO::sendfile $ofh, $ifh, $offset, $count
		276	IO::AIO::fadvise $fh, $offset, $len, $advice
		277	IO::AIO::mmap $scalar, $length, $prot, $flags[, $fh[, $offset]]
		278	IO::AIO::munmap $scalar
		279	IO::AIO::madvise $scalar, $offset, $length, $advice
		280	IO::AIO::mprotect $scalar, $offset, $length, $protect
		281	IO::AIO::munlock $scalar, $offset = 0, $length = undef
		282	IO::AIO::munlockall
		283
		284	=head2 API NOTES
225		285
226	All the C<aio_*> calls are more or less thin wrappers around the syscall	286	All the C<aio_*> calls are more or less thin wrappers around the syscall
227	with the same name (sans C<aio_>). The arguments are similar or identical,	287	with the same name (sans C<aio_>). The arguments are similar or identical,
228	and they all accept an additional (and optional) C<$callback> argument	288	and they all accept an additional (and optional) C<$callback> argument
229	which must be a code reference. This code reference will get called with	289	which must be a code reference. This code reference will be called after
230	the syscall return code (e.g. most syscalls return C<-1> on error, unlike	290	the syscall has been executed in an asynchronous fashion. The results
231	perl, which usually delivers "false") as its sole argument after the given	291	of the request will be passed as arguments to the callback (and, if an
232	syscall has been executed asynchronously.	292	error occured, in C<$!>) - for most requests the syscall return code (e.g.
		293	most syscalls return C<-1> on error, unlike perl, which usually delivers
		294	"false").
		295
		296	Some requests (such as C<aio_readdir>) pass the actual results and
		297	communicate failures by passing C<undef>.
233		298
234	All functions expecting a filehandle keep a copy of the filehandle	299	All functions expecting a filehandle keep a copy of the filehandle
235	internally until the request has finished.	300	internally until the request has finished.
236		301
237	All functions return request objects of type L<IO::AIO::REQ> that allow	302	All functions return request objects of type L<IO::AIO::REQ> that allow
238	further manipulation of those requests while they are in-flight.	303	further manipulation of those requests while they are in-flight.
239		304
240	The pathnames you pass to these routines I<must> be absolute and	305	The pathnames you pass to these routines I<should> be absolute. The
241	encoded as octets. The reason for the former is that at the time the	306	reason for this is that at the time the request is being executed, the
242	request is being executed, the current working directory could have	307	current working directory could have changed. Alternatively, you can
243	changed. Alternatively, you can make sure that you never change the	308	make sure that you never change the current working directory anywhere
244	current working directory anywhere in the program and then use relative	309	in the program and then use relative paths. You can also take advantage
245	paths.	310	of IO::AIOs working directory abstraction, that lets you specify paths
		311	relative to some previously-opened "working directory object" - see the
		312	description of the C<IO::AIO::WD> class later in this document.
246		313
247	To encode pathnames as octets, either make sure you either: a) always pass	314	To encode pathnames as octets, either make sure you either: a) always pass
248	in filenames you got from outside (command line, readdir etc.) without	315	in filenames you got from outside (command line, readdir etc.) without
249	tinkering, b) are ASCII or ISO 8859-1, c) use the Encode module and encode	316	tinkering, b) are in your native filesystem encoding, c) use the Encode
250	your pathnames to the locale (or other) encoding in effect in the user	317	module and encode your pathnames to the locale (or other) encoding in
251	environment, d) use Glib::filename_from_unicode on unicode filenames or e)	318	effect in the user environment, d) use Glib::filename_from_unicode on
252	use something else to ensure your scalar has the correct contents.	319	unicode filenames or e) use something else to ensure your scalar has the
		320	correct contents.
253		321
254	This works, btw. independent of the internal UTF-8 bit, which IO::AIO	322	This works, btw. independent of the internal UTF-8 bit, which IO::AIO
255	handles correctly whether it is set or not.	323	handles correctly whether it is set or not.
		324
		325	=head2 AIO REQUEST FUNCTIONS
256		326
257	=over 4	327	=over 4
258		328
259	=item $prev_pri = aioreq_pri [$pri]	329	=item $prev_pri = aioreq_pri [$pri]
260		330
…		…
307	by the umask in effect then the request is being executed, so better never	377	by the umask in effect then the request is being executed, so better never
308	change the umask.	378	change the umask.
309		379
310	Example:	380	Example:
311		381
312	aio_open "/etc/passwd", O_RDONLY, 0, sub {	382	aio_open "/etc/passwd", IO::AIO::O_RDONLY, 0, sub {
313	if ($_[0]) {	383	if ($_[0]) {
314	print "open successful, fh is $_[0]\n";	384	print "open successful, fh is $_[0]\n";
315	...	385	...
316	} else {	386	} else {
317	die "open failed: $!\n";	387	die "open failed: $!\n";
318	}	388	}
319	};	389	};
320		390
		391	In addition to all the common open modes/flags (C<O_RDONLY>, C<O_WRONLY>,
		392	C<O_RDWR>, C<O_CREAT>, C<O_TRUNC>, C<O_EXCL> and C<O_APPEND>), the
		393	following POSIX and non-POSIX constants are available (missing ones on
		394	your system are, as usual, C<0>):
		395
		396	C<O_ASYNC>, C<O_DIRECT>, C<O_NOATIME>, C<O_CLOEXEC>, C<O_NOCTTY>, C<O_NOFOLLOW>,
		397	C<O_NONBLOCK>, C<O_EXEC>, C<O_SEARCH>, C<O_DIRECTORY>, C<O_DSYNC>,
		398	C<O_RSYNC>, C<O_SYNC> and C<O_TTY_INIT>.
		399
321		400
322	=item aio_close $fh, $callback->($status)	401	=item aio_close $fh, $callback->($status)
323		402
324	Asynchronously close a file and call the callback with the result	403	Asynchronously close a file and call the callback with the result
325	code.	404	code.
…		…
333		412
334	Or in other words: the file descriptor will be closed, but it will not be	413	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.	414	free for reuse until the perl filehandle is closed.
336		415
337	=cut	416	=cut
		417
		418	=item aio_seek $fh, $offset, $whence, $callback->($offs)
		419
		420	Seeks the filehandle to the new C<$offset>, similarly to perl's
		421	C<sysseek>. The C<$whence> can use the traditional values (C<0> for
		422	C<IO::AIO::SEEK_SET>, C<1> for C<IO::AIO::SEEK_CUR> or C<2> for
		423	C<IO::AIO::SEEK_END>).
		424
		425	The resulting absolute offset will be passed to the callback, or C<-1> in
		426	case of an error.
		427
		428	In theory, the C<$whence> constants could be different than the
		429	corresponding values from L<Fcntl>, but perl guarantees they are the same,
		430	so don't panic.
		431
		432	As a GNU/Linux (and maybe Solaris) extension, also the constants
		433	C<IO::AIO::SEEK_DATA> and C<IO::AIO::SEEK_HOLE> are available, if they
		434	could be found. No guarantees about suitability for use in C<aio_seek> or
		435	Perl's C<sysseek> can be made though, although I would naively assume they
		436	"just work".
338		437
339	=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)	438	=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
340		439
341	=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)	440	=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
342		441
…		…
375		474
376	Tries to copy C<$length> bytes from C<$in_fh> to C<$out_fh>. It starts	475	Tries to copy C<$length> bytes from C<$in_fh> to C<$out_fh>. It starts
377	reading at byte offset C<$in_offset>, and starts writing at the current	476	reading at byte offset C<$in_offset>, and starts writing at the current
378	file offset of C<$out_fh>. Because of that, it is not safe to issue more	477	file offset of C<$out_fh>. Because of that, it is not safe to issue more
379	than one C<aio_sendfile> per C<$out_fh>, as they will interfere with each	478	than one C<aio_sendfile> per C<$out_fh>, as they will interfere with each
380	other.	479	other. The same C<$in_fh> works fine though, as this function does not
		480	move or use the file offset of C<$in_fh>.
381		481
		482	Please note that C<aio_sendfile> can read more bytes from C<$in_fh> than
		483	are written, and there is no way to find out how many more bytes have been
		484	read from C<aio_sendfile> alone, as C<aio_sendfile> only provides the
		485	number of bytes written to C<$out_fh>. Only if the result value equals
		486	C<$length> one can assume that C<$length> bytes have been read.
		487
		488	Unlike with other C<aio_> functions, it makes a lot of sense to use
		489	C<aio_sendfile> on non-blocking sockets, as long as one end (typically
		490	the C<$in_fh>) is a file - the file I/O will then be asynchronous, while
		491	the socket I/O will be non-blocking. Note, however, that you can run
		492	into a trap where C<aio_sendfile> reads some data with readahead, then
		493	fails to write all data, and when the socket is ready the next time, the
		494	data in the cache is already lost, forcing C<aio_sendfile> to again hit
		495	the disk. Explicit C<aio_read> + C<aio_write> let's you better control
		496	resource usage.
		497
382	This call tries to make use of a native C<sendfile> syscall to provide	498	This call tries to make use of a native C<sendfile>-like syscall to
383	zero-copy operation. For this to work, C<$out_fh> should refer to a	499	provide zero-copy operation. For this to work, C<$out_fh> should refer to
384	socket, and C<$in_fh> should refer to mmap'able file.	500	a socket, and C<$in_fh> should refer to an mmap'able file.
385		501
386	If a native sendfile cannot be found or it fails with C<ENOSYS>,	502	If a native sendfile cannot be found or it fails with C<ENOSYS>,
387	C<ENOTSUP>, C<EOPNOTSUPP>, C<EAFNOSUPPORT>, C<EPROTOTYPE> or C<ENOTSOCK>,	503	C<EINVAL>, C<ENOTSUP>, C<EOPNOTSUPP>, C<EAFNOSUPPORT>, C<EPROTOTYPE> or
388	it will be emulated, so you can call C<aio_sendfile> on any type of	504	C<ENOTSOCK>, it will be emulated, so you can call C<aio_sendfile> on any
389	filehandle regardless of the limitations of the operating system.	505	type of filehandle regardless of the limitations of the operating system.
390		506
391	Please note, however, that C<aio_sendfile> can read more bytes from	507	As native sendfile syscalls (as practically any non-POSIX interface hacked
392	C<$in_fh> than are written, and there is no way to find out how many	508	together in a hurry to improve benchmark numbers) tend to be rather buggy
393	bytes have been read from C<aio_sendfile> alone, as C<aio_sendfile> only	509	on many systems, this implementation tries to work around some known bugs
394	provides the number of bytes written to C<$out_fh>. Only if the result	510	in Linux and FreeBSD kernels (probably others, too), but that might fail,
395	value equals C<$length> one can assume that C<$length> bytes have been	511	so you really really should check the return value of C<aio_sendfile> -
396	read.	512	fewre bytes than expected might have been transferred.
397		513
398		514
399	=item aio_readahead $fh,$offset,$length, $callback->($retval)	515	=item aio_readahead $fh,$offset,$length, $callback->($retval)
400		516
401	C<aio_readahead> populates the page cache with data from a file so that	517	C<aio_readahead> populates the page cache with data from a file so that
…		…
424		540
425	Currently, the stats are always 64-bit-stats, i.e. instead of returning an	541	Currently, the stats are always 64-bit-stats, i.e. instead of returning an
426	error when stat'ing a large file, the results will be silently truncated	542	error when stat'ing a large file, the results will be silently truncated
427	unless perl itself is compiled with large file support.	543	unless perl itself is compiled with large file support.
428		544
		545	To help interpret the mode and dev/rdev stat values, IO::AIO offers the
		546	following constants and functions (if not implemented, the constants will
		547	be C<0> and the functions will either C<croak> or fall back on traditional
		548	behaviour).
		549
		550	C<S_IFMT>, C<S_IFIFO>, C<S_IFCHR>, C<S_IFBLK>, C<S_IFLNK>, C<S_IFREG>,
		551	C<S_IFDIR>, C<S_IFWHT>, C<S_IFSOCK>, C<IO::AIO::major $dev_t>,
		552	C<IO::AIO::minor $dev_t>, C<IO::AIO::makedev $major, $minor>.
		553
429	Example: Print the length of F</etc/passwd>:	554	Example: Print the length of F</etc/passwd>:
430		555
431	aio_stat "/etc/passwd", sub {	556	aio_stat "/etc/passwd", sub {
432	$_[0] and die "stat failed: $!";	557	$_[0] and die "stat failed: $!";
433	print "size is ", -s _, "\n";	558	print "size is ", -s _, "\n";
434	};	559	};
435		560
436		561
		562	=item aio_statvfs $fh_or_path, $callback->($statvfs)
		563
		564	Works like the POSIX C<statvfs> or C<fstatvfs> syscalls, depending on
		565	whether a file handle or path was passed.
		566
		567	On success, the callback is passed a hash reference with the following
		568	members: C<bsize>, C<frsize>, C<blocks>, C<bfree>, C<bavail>, C<files>,
		569	C<ffree>, C<favail>, C<fsid>, C<flag> and C<namemax>. On failure, C<undef>
		570	is passed.
		571
		572	The following POSIX IO::AIO::ST_* constants are defined: C<ST_RDONLY> and
		573	C<ST_NOSUID>.
		574
		575	The following non-POSIX IO::AIO::ST_* flag masks are defined to
		576	their correct value when available, or to C<0> on systems that do
		577	not support them: C<ST_NODEV>, C<ST_NOEXEC>, C<ST_SYNCHRONOUS>,
		578	C<ST_MANDLOCK>, C<ST_WRITE>, C<ST_APPEND>, C<ST_IMMUTABLE>, C<ST_NOATIME>,
		579	C<ST_NODIRATIME> and C<ST_RELATIME>.
		580
		581	Example: stat C</wd> and dump out the data if successful.
		582
		583	aio_statvfs "/wd", sub {
		584	my $f = $_[0]
		585	or die "statvfs: $!";
		586
		587	use Data::Dumper;
		588	say Dumper $f;
		589	};
		590
		591	# result:
		592	{
		593	bsize => 1024,
		594	bfree => 4333064312,
		595	blocks => 10253828096,
		596	files => 2050765568,
		597	flag => 4096,
		598	favail => 2042092649,
		599	bavail => 4333064312,
		600	ffree => 2042092649,
		601	namemax => 255,
		602	frsize => 1024,
		603	fsid => 1810
		604	}
		605
		606
437	=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status)	607	=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
438		608
439	Works like perl's C<utime> function (including the special case of $atime	609	Works like perl's C<utime> function (including the special case of $atime
440	and $mtime being undef). Fractional times are supported if the underlying	610	and $mtime being undef). Fractional times are supported if the underlying
441	syscalls support them.	611	syscalls support them.
…		…
479		649
480	Asynchronously unlink (delete) a file and call the callback with the	650	Asynchronously unlink (delete) a file and call the callback with the
481	result code.	651	result code.
482		652
483		653
484	=item aio_mknod $path, $mode, $dev, $callback->($status)	654	=item aio_mknod $pathname, $mode, $dev, $callback->($status)
485		655
486	[EXPERIMENTAL]	656	[EXPERIMENTAL]
487		657
488	Asynchronously create a device node (or fifo). See mknod(2).	658	Asynchronously create a device node (or fifo). See mknod(2).
489		659
490	The only (POSIX-) portable way of calling this function is:	660	The only (POSIX-) portable way of calling this function is:
491		661
492	aio_mknod $path, IO::AIO::S_IFIFO \| $mode, 0, sub { ...	662	aio_mknod $pathname, IO::AIO::S_IFIFO \| $mode, 0, sub { ...
493		663
		664	See C<aio_stat> for info about some potentially helpful extra constants
		665	and functions.
494		666
495	=item aio_link $srcpath, $dstpath, $callback->($status)	667	=item aio_link $srcpath, $dstpath, $callback->($status)
496		668
497	Asynchronously create a new link to the existing object at C<$srcpath> at	669	Asynchronously create a new link to the existing object at C<$srcpath> at
498	the path C<$dstpath> and call the callback with the result code.	670	the path C<$dstpath> and call the callback with the result code.
…		…
502		674
503	Asynchronously create a new symbolic link to the existing object at C<$srcpath> at	675	Asynchronously create a new symbolic link to the existing object at C<$srcpath> at
504	the path C<$dstpath> and call the callback with the result code.	676	the path C<$dstpath> and call the callback with the result code.
505		677
506		678
507	=item aio_readlink $path, $callback->($link)	679	=item aio_readlink $pathname, $callback->($link)
508		680
509	Asynchronously read the symlink specified by C<$path> and pass it to	681	Asynchronously read the symlink specified by C<$path> and pass it to
510	the callback. If an error occurs, nothing or undef gets passed to the	682	the callback. If an error occurs, nothing or undef gets passed to the
511	callback.	683	callback.
512		684
513		685
		686	=item aio_realpath $pathname, $callback->($path)
		687
		688	Asynchronously make the path absolute and resolve any symlinks in
		689	C<$path>. The resulting path only consists of directories (Same as
		690	L<Cwd::realpath>).
		691
		692	This request can be used to get the absolute path of the current working
		693	directory by passing it a path of F<.> (a single dot).
		694
		695
514	=item aio_rename $srcpath, $dstpath, $callback->($status)	696	=item aio_rename $srcpath, $dstpath, $callback->($status)
515		697
516	Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as	698	Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as
517	rename(2) and call the callback with the result code.	699	rename(2) and call the callback with the result code.
518		700
…		…
540	array-ref with the filenames.	722	array-ref with the filenames.
541		723
542		724
543	=item aio_readdirx $pathname, $flags, $callback->($entries, $flags)	725	=item aio_readdirx $pathname, $flags, $callback->($entries, $flags)
544		726
545	Quite similar to C<aio_readdir>, but the C<$flags> argument allows to tune	727	Quite similar to C<aio_readdir>, but the C<$flags> argument allows one to
546	behaviour and output format. In case of an error, C<$entries> will be	728	tune behaviour and output format. In case of an error, C<$entries> will be
547	C<undef>.	729	C<undef>.
548		730
549	The flags are a combination of the following constants, ORed together (the	731	The flags are a combination of the following constants, ORed together (the
550	flags will also be passed to the callback, possibly modified):	732	flags will also be passed to the callback, possibly modified):
551		733
552	=over 4	734	=over 4
553		735
554	=item IO::AIO::READDIR_DENTS	736	=item IO::AIO::READDIR_DENTS
555		737
556	When this flag is off, then the callback gets an arrayref with of names	738	When this flag is off, then the callback gets an arrayref consisting of
557	only (as with C<aio_readdir>), otherwise it gets an arrayref with	739	names only (as with C<aio_readdir>), otherwise it gets an arrayref with
558	C<[$name, $type, $inode]> arrayrefs, each describing a single directory	740	C<[$name, $type, $inode]> arrayrefs, each describing a single directory
559	entry in more detail.	741	entry in more detail.
560		742
561	C<$name> is the name of the entry.	743	C<$name> is the name of the entry.
562		744
…		…
575	systems that do not deliver the inode information.	757	systems that do not deliver the inode information.
576		758
577	=item IO::AIO::READDIR_DIRS_FIRST	759	=item IO::AIO::READDIR_DIRS_FIRST
578		760
579	When this flag is set, then the names will be returned in an order where	761	When this flag is set, then the names will be returned in an order where
580	likely directories come first. This is useful when you need to quickly	762	likely directories come first, in optimal stat order. This is useful when
581	find directories, or you want to find all directories while avoiding to	763	you need to quickly find directories, or you want to find all directories
582	stat() each entry.	764	while avoiding to stat() each entry.
583		765
584	If the system returns type information in readdir, then this is used	766	If the system returns type information in readdir, then this is used
585	to find directories directly. Otherwise, likely directories are files	767	to find directories directly. Otherwise, likely directories are names
586	beginning with ".", or otherwise files with no dots, of which files with	768	beginning with ".", or otherwise names with no dots, of which names with
587	short names are tried first.	769	short names are tried first.
588		770
589	=item IO::AIO::READDIR_STAT_ORDER	771	=item IO::AIO::READDIR_STAT_ORDER
590		772
591	When this flag is set, then the names will be returned in an order	773	When this flag is set, then the names will be returned in an order
…		…
598		780
599	=item IO::AIO::READDIR_FOUND_UNKNOWN	781	=item IO::AIO::READDIR_FOUND_UNKNOWN
600		782
601	This flag should not be set when calling C<aio_readdirx>. Instead, it	783	This flag should not be set when calling C<aio_readdirx>. Instead, it
602	is being set by C<aio_readdirx>, when any of the C<$type>'s found were	784	is being set by C<aio_readdirx>, when any of the C<$type>'s found were
603	C<IO::AIO::DT_UNKNOWN>. The absense of this flag therefore indicates that all	785	C<IO::AIO::DT_UNKNOWN>. The absence of this flag therefore indicates that all
604	C<$type>'s are known, which can be used to speed up some algorithms.	786	C<$type>'s are known, which can be used to speed up some algorithms.
605		787
606	=back	788	=back
607		789
608		790
609	=item aio_load $path, $data, $callback->($status)	791	=item aio_load $pathname, $data, $callback->($status)
610		792
611	This is a composite request that tries to fully load the given file into	793	This is a composite request that tries to fully load the given file into
612	memory. Status is the same as with aio_read.	794	memory. Status is the same as with aio_read.
613		795
614	=cut	796	=cut
…		…
736	if ($_[0] && $! == EXDEV) {	918	if ($_[0] && $! == EXDEV) {
737	aioreq_pri $pri;	919	aioreq_pri $pri;
738	add $grp aio_copy $src, $dst, sub {	920	add $grp aio_copy $src, $dst, sub {
739	$grp->result ($_[0]);	921	$grp->result ($_[0]);
740		922
741	if (!$_[0]) {	923	unless ($_[0]) {
742	aioreq_pri $pri;	924	aioreq_pri $pri;
743	add $grp aio_unlink $src;	925	add $grp aio_unlink $src;
744	}	926	}
745	};	927	};
746	} else {	928	} else {
…		…
749	};	931	};
750		932
751	$grp	933	$grp
752	}	934	}
753		935
754	=item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs)	936	=item aio_scandir $pathname, $maxreq, $callback->($dirs, $nondirs)
755		937
756	Scans a directory (similar to C<aio_readdir>) but additionally tries to	938	Scans a directory (similar to C<aio_readdir>) but additionally tries to
757	efficiently separate the entries of directory C<$path> into two sets of	939	efficiently separate the entries of directory C<$path> into two sets of
758	names, directories you can recurse into (directories), and ones you cannot	940	names, directories you can recurse into (directories), and ones you cannot
759	recurse into (everything else, including symlinks to directories).	941	recurse into (everything else, including symlinks to directories).
…		…
790	Then entries will be sorted into likely directories a non-initial dot	972	Then entries will be sorted into likely directories a non-initial dot
791	currently) and likely non-directories (see C<aio_readdirx>). Then every	973	currently) and likely non-directories (see C<aio_readdirx>). Then every
792	entry plus an appended C</.> will be C<stat>'ed, likely directories first,	974	entry plus an appended C</.> will be C<stat>'ed, likely directories first,
793	in order of their inode numbers. If that succeeds, it assumes that the	975	in order of their inode numbers. If that succeeds, it assumes that the
794	entry is a directory or a symlink to directory (which will be checked	976	entry is a directory or a symlink to directory (which will be checked
795	seperately). This is often faster than stat'ing the entry itself because	977	separately). This is often faster than stat'ing the entry itself because
796	filesystems might detect the type of the entry without reading the inode	978	filesystems might detect the type of the entry without reading the inode
797	data (e.g. ext2fs filetype feature), even on systems that cannot return	979	data (e.g. ext2fs filetype feature), even on systems that cannot return
798	the filetype information on readdir.	980	the filetype information on readdir.
799		981
800	If the known number of directories (link count - 2) has been reached, the	982	If the known number of directories (link count - 2) has been reached, the
…		…
816		998
817	my $grp = aio_group $cb;	999	my $grp = aio_group $cb;
818		1000
819	$maxreq = 4 if $maxreq <= 0;	1001	$maxreq = 4 if $maxreq <= 0;
820		1002
821	# stat once	1003	# get a wd object
822	aioreq_pri $pri;	1004	aioreq_pri $pri;
823	add $grp aio_stat $path, sub {	1005	add $grp aio_wd $path, sub {
		1006	$_[0]
824	return $grp->result () if $_[0];	1007	or return $grp->result ();
825	my $now = time;
826	my $hash1 = join ":", (stat _)[0,1,3,7,9];
827		1008
828	# read the directory entries	1009	my $wd = [shift, "."];
		1010
		1011	# stat once
829	aioreq_pri $pri;	1012	aioreq_pri $pri;
830	add $grp aio_readdirx $path, READDIR_DIRS_FIRST, sub {	1013	add $grp aio_stat $wd, sub {
831	my $entries = shift
832	or return $grp->result ();	1014	return $grp->result () if $_[0];
		1015	my $now = time;
		1016	my $hash1 = join ":", (stat _)[0,1,3,7,9];
833		1017
834	# stat the dir another time	1018	# read the directory entries
835	aioreq_pri $pri;	1019	aioreq_pri $pri;
		1020	add $grp aio_readdirx $wd, READDIR_DIRS_FIRST, sub {
		1021	my $entries = shift
		1022	or return $grp->result ();
		1023
		1024	# stat the dir another time
		1025	aioreq_pri $pri;
836	add $grp aio_stat $path, sub {	1026	add $grp aio_stat $wd, sub {
837	my $hash2 = join ":", (stat _)[0,1,3,7,9];	1027	my $hash2 = join ":", (stat _)[0,1,3,7,9];
838		1028
839	my $ndirs;	1029	my $ndirs;
840		1030
841	# take the slow route if anything looks fishy	1031	# take the slow route if anything looks fishy
842	if ($hash1 ne $hash2 or (stat _)[9] == $now) {	1032	if ($hash1 ne $hash2 or (stat _)[9] == $now) {
843	$ndirs = -1;	1033	$ndirs = -1;
844	} else {	1034	} else {
845	# if nlink == 2, we are finished	1035	# if nlink == 2, we are finished
846	# for non-posix-fs's, we rely on nlink < 2	1036	# for non-posix-fs's, we rely on nlink < 2
847	$ndirs = (stat _)[3] - 2	1037	$ndirs = (stat _)[3] - 2
848	or return $grp->result ([], $entries);	1038	or return $grp->result ([], $entries);
849	}	1039	}
850		1040
851	my (@dirs, @nondirs);	1041	my (@dirs, @nondirs);
852		1042
853	my $statgrp = add $grp aio_group sub {	1043	my $statgrp = add $grp aio_group sub {
854	$grp->result (\@dirs, \@nondirs);	1044	$grp->result (\@dirs, \@nondirs);
855	};	1045	};
856		1046
857	limit $statgrp $maxreq;	1047	limit $statgrp $maxreq;
858	feed $statgrp sub {	1048	feed $statgrp sub {
859	return unless @$entries;	1049	return unless @$entries;
860	my $entry = shift @$entries;	1050	my $entry = shift @$entries;
861		1051
862	aioreq_pri $pri;	1052	aioreq_pri $pri;
		1053	$wd->[1] = "$entry/.";
863	add $statgrp aio_stat "$path/$entry/.", sub {	1054	add $statgrp aio_stat $wd, sub {
864	if ($_[0] < 0) {	1055	if ($_[0] < 0) {
865	push @nondirs, $entry;	1056	push @nondirs, $entry;
866	} else {	1057	} else {
867	# need to check for real directory	1058	# need to check for real directory
868	aioreq_pri $pri;	1059	aioreq_pri $pri;
		1060	$wd->[1] = $entry;
869	add $statgrp aio_lstat "$path/$entry", sub {	1061	add $statgrp aio_lstat $wd, sub {
870	if (-d _) {	1062	if (-d _) {
871	push @dirs, $entry;	1063	push @dirs, $entry;
872		1064
873	unless (--$ndirs) {	1065	unless (--$ndirs) {
874	push @nondirs, @$entries;	1066	push @nondirs, @$entries;
875	feed $statgrp;	1067	feed $statgrp;
		1068	}
		1069	} else {
		1070	push @nondirs, $entry;
876	}	1071	}
877	} else {
878	push @nondirs, $entry;
879	}	1072	}
880	}	1073	}
881	}	1074	};
882	};	1075	};
883	};	1076	};
884	};	1077	};
885	};	1078	};
886	};	1079	};
887		1080
888	$grp	1081	$grp
889	}	1082	}
890		1083
891	=item aio_rmtree $path, $callback->($status)	1084	=item aio_rmtree $pathname, $callback->($status)
892		1085
893	Delete a directory tree starting (and including) C<$path>, return the	1086	Delete a directory tree starting (and including) C<$path>, return the
894	status of the final C<rmdir> only. This is a composite request that	1087	status of the final C<rmdir> only. This is a composite request that
895	uses C<aio_scandir> to recurse into and rmdir directories, and unlink	1088	uses C<aio_scandir> to recurse into and rmdir directories, and unlink
896	everything else.	1089	everything else.
…		…
938	callback with the fdatasync result code.	1131	callback with the fdatasync result code.
939		1132
940	If this call isn't available because your OS lacks it or it couldn't be	1133	If this call isn't available because your OS lacks it or it couldn't be
941	detected, it will be emulated by calling C<fsync> instead.	1134	detected, it will be emulated by calling C<fsync> instead.
942		1135
		1136	=item aio_syncfs $fh, $callback->($status)
		1137
		1138	Asynchronously call the syncfs syscall to sync the filesystem associated
		1139	to the given filehandle and call the callback with the syncfs result
		1140	code. If syncfs is not available, calls sync(), but returns C<-1> and sets
		1141	errno to C<ENOSYS> nevertheless.
		1142
943	=item aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status)	1143	=item aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status)
944		1144
945	Sync the data portion of the file specified by C<$offset> and C<$length>	1145	Sync the data portion of the file specified by C<$offset> and C<$length>
946	to disk (but NOT the metadata), by calling the Linux-specific	1146	to disk (but NOT the metadata), by calling the Linux-specific
947	sync_file_range call. If sync_file_range is not available or it returns	1147	sync_file_range call. If sync_file_range is not available or it returns
…		…
950	C<$flags> can be a combination of C<IO::AIO::SYNC_FILE_RANGE_WAIT_BEFORE>,	1150	C<$flags> can be a combination of C<IO::AIO::SYNC_FILE_RANGE_WAIT_BEFORE>,
951	C<IO::AIO::SYNC_FILE_RANGE_WRITE> and	1151	C<IO::AIO::SYNC_FILE_RANGE_WRITE> and
952	C<IO::AIO::SYNC_FILE_RANGE_WAIT_AFTER>: refer to the sync_file_range	1152	C<IO::AIO::SYNC_FILE_RANGE_WAIT_AFTER>: refer to the sync_file_range
953	manpage for details.	1153	manpage for details.
954		1154
955	=item aio_pathsync $path, $callback->($status)	1155	=item aio_pathsync $pathname, $callback->($status)
956		1156
957	This request tries to open, fsync and close the given path. This is a	1157	This request tries to open, fsync and close the given path. This is a
958	composite request intended to sync directories after directory operations	1158	composite request intended to sync directories after directory operations
959	(E.g. rename). This might not work on all operating systems or have any	1159	(E.g. rename). This might not work on all operating systems or have any
960	specific effect, but usually it makes sure that directory changes get	1160	specific effect, but usually it makes sure that directory changes get
…		…
994	}	1194	}
995		1195
996	=item aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)	1196	=item aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
997		1197
998	This is a rather advanced IO::AIO call, which only works on mmap(2)ed	1198	This is a rather advanced IO::AIO call, which only works on mmap(2)ed
999	scalars (see the L<Sys::Mmap> or L<Mmap> modules for details on this, note	1199	scalars (see the C<IO::AIO::mmap> function, although it also works on data
		1200	scalars managed by the L<Sys::Mmap> or L<Mmap> modules, note that the
1000	that the scalar must only be modified in-place while an aio operation is	1201	scalar must only be modified in-place while an aio operation is pending on
1001	pending on it).	1202	it).
1002		1203
1003	It calls the C<msync> function of your OS, if available, with the memory	1204	It calls the C<msync> function of your OS, if available, with the memory
1004	area starting at C<$offset> in the string and ending C<$length> bytes	1205	area starting at C<$offset> in the string and ending C<$length> bytes
1005	later. If C<$length> is negative, counts from the end, and if C<$length>	1206	later. If C<$length> is negative, counts from the end, and if C<$length>
1006	is C<undef>, then it goes till the end of the string. The flags can be	1207	is C<undef>, then it goes till the end of the string. The flags can be
…		…
1017	as for C<aio_msync>, above, except for flags, which must be either	1218	as for C<aio_msync>, above, except for flags, which must be either
1018	C<0> (which reads all pages and ensures they are instantiated) or	1219	C<0> (which reads all pages and ensures they are instantiated) or
1019	C<IO::AIO::MT_MODIFY>, which modifies the memory page s(by reading and	1220	C<IO::AIO::MT_MODIFY>, which modifies the memory page s(by reading and
1020	writing an octet from it, which dirties the page).	1221	writing an octet from it, which dirties the page).
1021		1222
		1223	=item aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status)
		1224
		1225	This is a rather advanced IO::AIO call, which works best on mmap(2)ed
		1226	scalars.
		1227
		1228	It reads in all the pages of the underlying storage into memory (if any)
		1229	and locks them, so they are not getting swapped/paged out or removed.
		1230
		1231	If C<$length> is undefined, then the scalar will be locked till the end.
		1232
		1233	On systems that do not implement C<mlock>, this function returns C<-1>
		1234	and sets errno to C<ENOSYS>.
		1235
		1236	Note that the corresponding C<munlock> is synchronous and is
		1237	documented under L<MISCELLANEOUS FUNCTIONS>.
		1238
		1239	Example: open a file, mmap and mlock it - both will be undone when
		1240	C<$data> gets destroyed.
		1241
		1242	open my $fh, "<", $path or die "$path: $!";
		1243	my $data;
		1244	IO::AIO::mmap $data, -s $fh, IO::AIO::PROT_READ, IO::AIO::MAP_SHARED, $fh;
		1245	aio_mlock $data; # mlock in background
		1246
		1247	=item aio_mlockall $flags, $callback->($status)
		1248
		1249	Calls the C<mlockall> function with the given C<$flags> (a combination of
		1250	C<IO::AIO::MCL_CURRENT> and C<IO::AIO::MCL_FUTURE>).
		1251
		1252	On systems that do not implement C<mlockall>, this function returns C<-1>
		1253	and sets errno to C<ENOSYS>.
		1254
		1255	Note that the corresponding C<munlockall> is synchronous and is
		1256	documented under L<MISCELLANEOUS FUNCTIONS>.
		1257
		1258	Example: asynchronously lock all current and future pages into memory.
		1259
		1260	aio_mlockall IO::AIO::MCL_FUTURE;
		1261
		1262	=item aio_fiemap $fh, $start, $length, $flags, $count, $cb->(\@extents)
		1263
		1264	Queries the extents of the given file (by calling the Linux FIEMAP ioctl,
		1265	see L<http://cvs.schmorp.de/IO-AIO/doc/fiemap.txt> for details). If the
		1266	C<ioctl> is not available on your OS, then this rquiest will fail with
		1267	C<ENOSYS>.
		1268
		1269	C<$start> is the starting offset to query extents for, C<$length> is the
		1270	size of the range to query - if it is C<undef>, then the whole file will
		1271	be queried.
		1272
		1273	C<$flags> is a combination of flags (C<IO::AIO::FIEMAP_FLAG_SYNC> or
		1274	C<IO::AIO::FIEMAP_FLAG_XATTR> - C<IO::AIO::FIEMAP_FLAGS_COMPAT> is also
		1275	exported), and is normally C<0> or C<IO::AIO::FIEMAP_FLAG_SYNC> to query
		1276	the data portion.
		1277
		1278	C<$count> is the maximum number of extent records to return. If it is
		1279	C<undef>, then IO::AIO queries all extents of the file. As a very special
		1280	case, if it is C<0>, then the callback receives the number of extents
		1281	instead of the extents themselves.
		1282
		1283	If an error occurs, the callback receives no arguments. The special
		1284	C<errno> value C<IO::AIO::EBADR> is available to test for flag errors.
		1285
		1286	Otherwise, the callback receives an array reference with extent
		1287	structures. Each extent structure is an array reference itself, with the
		1288	following members:
		1289
		1290	[$logical, $physical, $length, $flags]
		1291
		1292	Flags is any combination of the following flag values (typically either C<0>
		1293	or C<IO::AIO::FIEMAP_EXTENT_LAST>):
		1294
		1295	C<IO::AIO::FIEMAP_EXTENT_LAST>, C<IO::AIO::FIEMAP_EXTENT_UNKNOWN>,
		1296	C<IO::AIO::FIEMAP_EXTENT_DELALLOC>, C<IO::AIO::FIEMAP_EXTENT_ENCODED>,
		1297	C<IO::AIO::FIEMAP_EXTENT_DATA_ENCRYPTED>, C<IO::AIO::FIEMAP_EXTENT_NOT_ALIGNED>,
		1298	C<IO::AIO::FIEMAP_EXTENT_DATA_INLINE>, C<IO::AIO::FIEMAP_EXTENT_DATA_TAIL>,
		1299	C<IO::AIO::FIEMAP_EXTENT_UNWRITTEN>, C<IO::AIO::FIEMAP_EXTENT_MERGED> or
		1300	C<IO::AIO::FIEMAP_EXTENT_SHARED>.
		1301
1022	=item aio_group $callback->(...)	1302	=item aio_group $callback->(...)
1023		1303
1024	This is a very special aio request: Instead of doing something, it is a	1304	This is a very special aio request: Instead of doing something, it is a
1025	container for other aio requests, which is useful if you want to bundle	1305	container for other aio requests, which is useful if you want to bundle
1026	many requests into a single, composite, request with a definite callback	1306	many requests into a single, composite, request with a definite callback
…		…
1062	like sleep and file handle readable/writable, the overhead this creates is	1342	like sleep and file handle readable/writable, the overhead this creates is
1063	immense (it blocks a thread for a long time) so do not use this function	1343	immense (it blocks a thread for a long time) so do not use this function
1064	except to put your application under artificial I/O pressure.	1344	except to put your application under artificial I/O pressure.
1065		1345
1066	=back	1346	=back
		1347
		1348
		1349	=head2 IO::AIO::WD - multiple working directories
		1350
		1351	Your process only has one current working directory, which is used by all
		1352	threads. This makes it hard to use relative paths (some other component
		1353	could call C<chdir> at any time, and it is hard to control when the path
		1354	will be used by IO::AIO).
		1355
		1356	One solution for this is to always use absolute paths. This usually works,
		1357	but can be quite slow (the kernel has to walk the whole path on every
		1358	access), and can also be a hassle to implement.
		1359
		1360	Newer POSIX systems have a number of functions (openat, fdopendir,
		1361	futimensat and so on) that make it possible to specify working directories
		1362	per operation.
		1363
		1364	For portability, and because the clowns who "designed", or shall I write,
		1365	perpetrated this new interface were obviously half-drunk, this abstraction
		1366	cannot be perfect, though.
		1367
		1368	IO::AIO allows you to convert directory paths into a so-called IO::AIO::WD
		1369	object. This object stores the canonicalised, absolute version of the
		1370	path, and on systems that allow it, also a directory file descriptor.
		1371
		1372	Everywhere where a pathname is accepted by IO::AIO (e.g. in C<aio_stat>
		1373	or C<aio_unlink>), one can specify an array reference with an IO::AIO::WD
		1374	object and a pathname instead (or the IO::AIO::WD object alone, which
		1375	gets interpreted as C<[$wd, "."]>). If the pathname is absolute, the
		1376	IO::AIO::WD object is ignored, otherwise the pathname is resolved relative
		1377	to that IO::AIO::WD object.
		1378
		1379	For example, to get a wd object for F</etc> and then stat F<passwd>
		1380	inside, you would write:
		1381
		1382	aio_wd "/etc", sub {
		1383	my $etcdir = shift;
		1384
		1385	# although $etcdir can be undef on error, there is generally no reason
		1386	# to check for errors here, as aio_stat will fail with ENOENT
		1387	# when $etcdir is undef.
		1388
		1389	aio_stat [$etcdir, "passwd"], sub {
		1390	# yay
		1391	};
		1392	};
		1393
		1394	That C<aio_wd> is a request and not a normal function shows that creating
		1395	an IO::AIO::WD object is itself a potentially blocking operation, which is
		1396	why it is done asynchronously.
		1397
		1398	To stat the directory obtained with C<aio_wd> above, one could write
		1399	either of the following three request calls:
		1400
		1401	aio_lstat "/etc" , sub { ... # pathname as normal string
		1402	aio_lstat [$wd, "."], sub { ... # "." relative to $wd (i.e. $wd itself)
		1403	aio_lstat $wd , sub { ... # shorthand for the previous
		1404
		1405	As with normal pathnames, IO::AIO keeps a copy of the working directory
		1406	object and the pathname string, so you could write the following without
		1407	causing any issues due to C<$path> getting reused:
		1408
		1409	my $path = [$wd, undef];
		1410
		1411	for my $name (qw(abc def ghi)) {
		1412	$path->[1] = $name;
		1413	aio_stat $path, sub {
		1414	# ...
		1415	};
		1416	}
		1417
		1418	There are some caveats: when directories get renamed (or deleted), the
		1419	pathname string doesn't change, so will point to the new directory (or
		1420	nowhere at all), while the directory fd, if available on the system,
		1421	will still point to the original directory. Most functions accepting a
		1422	pathname will use the directory fd on newer systems, and the string on
		1423	older systems. Some functions (such as realpath) will always rely on the
		1424	string form of the pathname.
		1425
		1426	So this fucntionality is mainly useful to get some protection against
		1427	C<chdir>, to easily get an absolute path out of a relative path for future
		1428	reference, and to speed up doing many operations in the same directory
		1429	(e.g. when stat'ing all files in a directory).
		1430
		1431	The following functions implement this working directory abstraction:
		1432
		1433	=over 4
		1434
		1435	=item aio_wd $pathname, $callback->($wd)
		1436
		1437	Asynchonously canonicalise the given pathname and convert it to an
		1438	IO::AIO::WD object representing it. If possible and supported on the
		1439	system, also open a directory fd to speed up pathname resolution relative
		1440	to this working directory.
		1441
		1442	If something goes wrong, then C<undef> is passwd to the callback instead
		1443	of a working directory object and C<$!> is set appropriately. Since
		1444	passing C<undef> as working directory component of a pathname fails the
		1445	request with C<ENOENT>, there is often no need for error checking in the
		1446	C<aio_wd> callback, as future requests using the value will fail in the
		1447	expected way.
		1448
		1449	If this call isn't available because your OS lacks it or it couldn't be
		1450	detected, it will be emulated by calling C<fsync> instead.
		1451
		1452	=item IO::AIO::CWD
		1453
		1454	This is a compiletime constant (object) that represents the process
		1455	current working directory.
		1456
		1457	Specifying this object as working directory object for a pathname is as
		1458	if the pathname would be specified directly, without a directory object,
		1459	e.g., these calls are functionally identical:
		1460
		1461	aio_stat "somefile", sub { ... };
		1462	aio_stat [IO::AIO::CWD, "somefile"], sub { ... };
		1463
		1464	=back
		1465
1067		1466
1068	=head2 IO::AIO::REQ CLASS	1467	=head2 IO::AIO::REQ CLASS
1069		1468
1070	All non-aggregate C<aio_*> functions return an object of this class when	1469	All non-aggregate C<aio_*> functions return an object of this class when
1071	called in non-void context.	1470	called in non-void context.
…		…
1189		1588
1190	Sets a feeder/generator on this group: every group can have an attached	1589	Sets a feeder/generator on this group: every group can have an attached
1191	generator that generates requests if idle. The idea behind this is that,	1590	generator that generates requests if idle. The idea behind this is that,
1192	although you could just queue as many requests as you want in a group,	1591	although you could just queue as many requests as you want in a group,
1193	this might starve other requests for a potentially long time. For example,	1592	this might starve other requests for a potentially long time. For example,
1194	C<aio_scandir> might generate hundreds of thousands C<aio_stat> requests,	1593	C<aio_scandir> might generate hundreds of thousands of C<aio_stat>
1195	delaying any later requests for a long time.	1594	requests, delaying any later requests for a long time.
1196		1595
1197	To avoid this, and allow incremental generation of requests, you can	1596	To avoid this, and allow incremental generation of requests, you can
1198	instead a group and set a feeder on it that generates those requests. The	1597	instead a group and set a feeder on it that generates those requests. The
1199	feed callback will be called whenever there are few enough (see C<limit>,	1598	feed callback will be called whenever there are few enough (see C<limit>,
1200	below) requests active in the group itself and is expected to queue more	1599	below) requests active in the group itself and is expected to queue more
…		…
1249		1648
1250	See C<poll_cb> for an example.	1649	See C<poll_cb> for an example.
1251		1650
1252	=item IO::AIO::poll_cb	1651	=item IO::AIO::poll_cb
1253		1652
1254	Process some outstanding events on the result pipe. You have to call this	1653	Process some outstanding events on the result pipe. You have to call
1255	regularly. Returns C<0> if all events could be processed, or C<-1> if it	1654	this regularly. Returns C<0> if all events could be processed (or there
1256	returned earlier for whatever reason. Returns immediately when no events	1655	were no events to process), or C<-1> if it returned earlier for whatever
1257	are outstanding. The amount of events processed depends on the settings of	1656	reason. Returns immediately when no events are outstanding. The amount of
1258	C<IO::AIO::max_poll_req> and C<IO::AIO::max_poll_time>.	1657	events processed depends on the settings of C<IO::AIO::max_poll_req> and
		1658	C<IO::AIO::max_poll_time>.
1259		1659
1260	If not all requests were processed for whatever reason, the filehandle	1660	If not all requests were processed for whatever reason, the filehandle
1261	will still be ready when C<poll_cb> returns, so normally you don't have to	1661	will still be ready when C<poll_cb> returns, so normally you don't have to
1262	do anything special to have it called later.	1662	do anything special to have it called later.
1263		1663
		1664	Apart from calling C<IO::AIO::poll_cb> when the event filehandle becomes
		1665	ready, it can be beneficial to call this function from loops which submit
		1666	a lot of requests, to make sure the results get processed when they become
		1667	available and not just when the loop is finished and the event loop takes
		1668	over again. This function returns very fast when there are no outstanding
		1669	requests.
		1670
1264	Example: Install an Event watcher that automatically calls	1671	Example: Install an Event watcher that automatically calls
1265	IO::AIO::poll_cb with high priority (more examples can be found in the	1672	IO::AIO::poll_cb with high priority (more examples can be found in the
1266	SYNOPSIS section, at the top of this document):	1673	SYNOPSIS section, at the top of this document):
1267		1674
1268	Event->io (fd => IO::AIO::poll_fileno,	1675	Event->io (fd => IO::AIO::poll_fileno,
1269	poll => 'r', async => 1,	1676	poll => 'r', async => 1,
1270	cb => \&IO::AIO::poll_cb);	1677	cb => \&IO::AIO::poll_cb);
		1678
		1679	=item IO::AIO::poll_wait
		1680
		1681	If there are any outstanding requests and none of them in the result
		1682	phase, wait till the result filehandle becomes ready for reading (simply
		1683	does a C<select> on the filehandle. This is useful if you want to
		1684	synchronously wait for some requests to finish).
		1685
		1686	See C<nreqs> for an example.
		1687
		1688	=item IO::AIO::poll
		1689
		1690	Waits until some requests have been handled.
		1691
		1692	Returns the number of requests processed, but is otherwise strictly
		1693	equivalent to:
		1694
		1695	IO::AIO::poll_wait, IO::AIO::poll_cb
		1696
		1697	=item IO::AIO::flush
		1698
		1699	Wait till all outstanding AIO requests have been handled.
		1700
		1701	Strictly equivalent to:
		1702
		1703	IO::AIO::poll_wait, IO::AIO::poll_cb
		1704	while IO::AIO::nreqs;
1271		1705
1272	=item IO::AIO::max_poll_reqs $nreqs	1706	=item IO::AIO::max_poll_reqs $nreqs
1273		1707
1274	=item IO::AIO::max_poll_time $seconds	1708	=item IO::AIO::max_poll_time $seconds
1275		1709
…		…
1300	# use a low priority so other tasks have priority	1734	# use a low priority so other tasks have priority
1301	Event->io (fd => IO::AIO::poll_fileno,	1735	Event->io (fd => IO::AIO::poll_fileno,
1302	poll => 'r', nice => 1,	1736	poll => 'r', nice => 1,
1303	cb => &IO::AIO::poll_cb);	1737	cb => &IO::AIO::poll_cb);
1304		1738
1305	=item IO::AIO::poll_wait
1306
1307	If there are any outstanding requests and none of them in the result
1308	phase, wait till the result filehandle becomes ready for reading (simply
1309	does a C<select> on the filehandle. This is useful if you want to
1310	synchronously wait for some requests to finish).
1311
1312	See C<nreqs> for an example.
1313
1314	=item IO::AIO::poll
1315
1316	Waits until some requests have been handled.
1317
1318	Returns the number of requests processed, but is otherwise strictly
1319	equivalent to:
1320
1321	IO::AIO::poll_wait, IO::AIO::poll_cb
1322
1323	=item IO::AIO::flush
1324
1325	Wait till all outstanding AIO requests have been handled.
1326
1327	Strictly equivalent to:
1328
1329	IO::AIO::poll_wait, IO::AIO::poll_cb
1330	while IO::AIO::nreqs;
1331
1332	=back	1739	=back
1333		1740
1334	=head3 CONTROLLING THE NUMBER OF THREADS	1741	=head3 CONTROLLING THE NUMBER OF THREADS
1335		1742
1336	=over	1743	=over
…		…
1369		1776
1370	Under normal circumstances you don't need to call this function.	1777	Under normal circumstances you don't need to call this function.
1371		1778
1372	=item IO::AIO::max_idle $nthreads	1779	=item IO::AIO::max_idle $nthreads
1373		1780
1374	Limit the number of threads (default: 4) that are allowed to idle (i.e.,	1781	Limit the number of threads (default: 4) that are allowed to idle
1375	threads that did not get a request to process within 10 seconds). That	1782	(i.e., threads that did not get a request to process within the idle
1376	means if a thread becomes idle while C<$nthreads> other threads are also	1783	timeout (default: 10 seconds). That means if a thread becomes idle while
1377	idle, it will free its resources and exit.	1784	C<$nthreads> other threads are also idle, it will free its resources and
		1785	exit.
1378		1786
1379	This is useful when you allow a large number of threads (e.g. 100 or 1000)	1787	This is useful when you allow a large number of threads (e.g. 100 or 1000)
1380	to allow for extremely high load situations, but want to free resources	1788	to allow for extremely high load situations, but want to free resources
1381	under normal circumstances (1000 threads can easily consume 30MB of RAM).	1789	under normal circumstances (1000 threads can easily consume 30MB of RAM).
1382		1790
1383	The default is probably ok in most situations, especially if thread	1791	The default is probably ok in most situations, especially if thread
1384	creation is fast. If thread creation is very slow on your system you might	1792	creation is fast. If thread creation is very slow on your system you might
1385	want to use larger values.	1793	want to use larger values.
1386		1794
		1795	=item IO::AIO::idle_timeout $seconds
		1796
		1797	Sets the minimum idle timeout (default 10) after which worker threads are
		1798	allowed to exit. SEe C<IO::AIO::max_idle>.
		1799
1387	=item IO::AIO::max_outstanding $maxreqs	1800	=item IO::AIO::max_outstanding $maxreqs
		1801
		1802	Sets the maximum number of outstanding requests to C<$nreqs>. If
		1803	you do queue up more than this number of requests, the next call to
		1804	C<IO::AIO::poll_cb> (and other functions calling C<poll_cb>, such as
		1805	C<IO::AIO::flush> or C<IO::AIO::poll>) will block until the limit is no
		1806	longer exceeded.
		1807
		1808	In other words, this setting does not enforce a queue limit, but can be
		1809	used to make poll functions block if the limit is exceeded.
1388		1810
1389	This is a very bad function to use in interactive programs because it	1811	This is a very bad function to use in interactive programs because it
1390	blocks, and a bad way to reduce concurrency because it is inexact: Better	1812	blocks, and a bad way to reduce concurrency because it is inexact: Better
1391	use an C<aio_group> together with a feed callback.	1813	use an C<aio_group> together with a feed callback.
1392		1814
1393	Sets the maximum number of outstanding requests to C<$nreqs>. If you	1815	It's main use is in scripts without an event loop - when you want to stat
1394	do queue up more than this number of requests, the next call to the	1816	a lot of files, you can write somehting like this:
1395	C<poll_cb> (and C<poll_some> and other functions calling C<poll_cb>)
1396	function will block until the limit is no longer exceeded.
1397		1817
1398	The default value is very large, so there is no practical limit on the	1818	IO::AIO::max_outstanding 32;
1399	number of outstanding requests.
1400		1819
1401	You can still queue as many requests as you want. Therefore,	1820	for my $path (...) {
1402	C<max_outstanding> is mainly useful in simple scripts (with low values) or	1821	aio_stat $path , ...;
1403	as a stop gap to shield against fatal memory overflow (with large values).	1822	IO::AIO::poll_cb;
		1823	}
		1824
		1825	IO::AIO::flush;
		1826
		1827	The call to C<poll_cb> inside the loop will normally return instantly, but
		1828	as soon as more thna C<32> reqeusts are in-flight, it will block until
		1829	some requests have been handled. This keeps the loop from pushing a large
		1830	number of C<aio_stat> requests onto the queue.
		1831
		1832	The default value for C<max_outstanding> is very large, so there is no
		1833	practical limit on the number of outstanding requests.
1404		1834
1405	=back	1835	=back
1406		1836
1407	=head3 STATISTICAL INFORMATION	1837	=head3 STATISTICAL INFORMATION
1408		1838
…		…
1446		1876
1447	Returns the number of bytes copied, or C<-1> on error.	1877	Returns the number of bytes copied, or C<-1> on error.
1448		1878
1449	=item IO::AIO::fadvise $fh, $offset, $len, $advice	1879	=item IO::AIO::fadvise $fh, $offset, $len, $advice
1450		1880
1451	Simply calls the C<posix_fadvise> function (see it's	1881	Simply calls the C<posix_fadvise> function (see its
1452	manpage for details). The following advice constants are	1882	manpage for details). The following advice constants are
1453	avaiable: C<IO::AIO::FADV_NORMAL>, C<IO::AIO::FADV_SEQUENTIAL>,	1883	available: C<IO::AIO::FADV_NORMAL>, C<IO::AIO::FADV_SEQUENTIAL>,
1454	C<IO::AIO::FADV_RANDOM>, C<IO::AIO::FADV_NOREUSE>,	1884	C<IO::AIO::FADV_RANDOM>, C<IO::AIO::FADV_NOREUSE>,
1455	C<IO::AIO::FADV_WILLNEED>, C<IO::AIO::FADV_DONTNEED>.	1885	C<IO::AIO::FADV_WILLNEED>, C<IO::AIO::FADV_DONTNEED>.
1456		1886
1457	On systems that do not implement C<posix_fadvise>, this function returns	1887	On systems that do not implement C<posix_fadvise>, this function returns
1458	ENOSYS, otherwise the return value of C<posix_fadvise>.	1888	ENOSYS, otherwise the return value of C<posix_fadvise>.
1459		1889
		1890	=item IO::AIO::madvise $scalar, $offset, $len, $advice
		1891
		1892	Simply calls the C<posix_madvise> function (see its
		1893	manpage for details). The following advice constants are
		1894	available: C<IO::AIO::MADV_NORMAL>, C<IO::AIO::MADV_SEQUENTIAL>,
		1895	C<IO::AIO::MADV_RANDOM>, C<IO::AIO::MADV_WILLNEED>, C<IO::AIO::MADV_DONTNEED>.
		1896
		1897	On systems that do not implement C<posix_madvise>, this function returns
		1898	ENOSYS, otherwise the return value of C<posix_madvise>.
		1899
		1900	=item IO::AIO::mprotect $scalar, $offset, $len, $protect
		1901
		1902	Simply calls the C<mprotect> function on the preferably AIO::mmap'ed
		1903	$scalar (see its manpage for details). The following protect
		1904	constants are available: C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_READ>,
		1905	C<IO::AIO::PROT_WRITE>, C<IO::AIO::PROT_EXEC>.
		1906
		1907	On systems that do not implement C<mprotect>, this function returns
		1908	ENOSYS, otherwise the return value of C<mprotect>.
		1909
		1910	=item IO::AIO::mmap $scalar, $length, $prot, $flags, $fh[, $offset]
		1911
		1912	Memory-maps a file (or anonymous memory range) and attaches it to the
		1913	given C<$scalar>, which will act like a string scalar.
		1914
		1915	The only operations allowed on the scalar are C<substr>/C<vec> that don't
		1916	change the string length, and most read-only operations such as copying it
		1917	or searching it with regexes and so on.
		1918
		1919	Anything else is unsafe and will, at best, result in memory leaks.
		1920
		1921	The memory map associated with the C<$scalar> is automatically removed
		1922	when the C<$scalar> is destroyed, or when the C<IO::AIO::mmap> or
		1923	C<IO::AIO::munmap> functions are called.
		1924
		1925	This calls the C<mmap>(2) function internally. See your system's manual
		1926	page for details on the C<$length>, C<$prot> and C<$flags> parameters.
		1927
		1928	The C<$length> must be larger than zero and smaller than the actual
		1929	filesize.
		1930
		1931	C<$prot> is a combination of C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_EXEC>,
		1932	C<IO::AIO::PROT_READ> and/or C<IO::AIO::PROT_WRITE>,
		1933
		1934	C<$flags> can be a combination of C<IO::AIO::MAP_SHARED> or
		1935	C<IO::AIO::MAP_PRIVATE>, or a number of system-specific flags (when
		1936	not available, the are defined as 0): C<IO::AIO::MAP_ANONYMOUS>
		1937	(which is set to C<MAP_ANON> if your system only provides this
		1938	constant), C<IO::AIO::MAP_HUGETLB>, C<IO::AIO::MAP_LOCKED>,
		1939	C<IO::AIO::MAP_NORESERVE>, C<IO::AIO::MAP_POPULATE> or
		1940	C<IO::AIO::MAP_NONBLOCK>
		1941
		1942	If C<$fh> is C<undef>, then a file descriptor of C<-1> is passed.
		1943
		1944	C<$offset> is the offset from the start of the file - it generally must be
		1945	a multiple of C<IO::AIO::PAGESIZE> and defaults to C<0>.
		1946
		1947	Example:
		1948
		1949	use Digest::MD5;
		1950	use IO::AIO;
		1951
		1952	open my $fh, "<verybigfile"
		1953	or die "$!";
		1954
		1955	IO::AIO::mmap my $data, -s $fh, IO::AIO::PROT_READ, IO::AIO::MAP_SHARED, $fh
		1956	or die "verybigfile: $!";
		1957
		1958	my $fast_md5 = md5 $data;
		1959
		1960	=item IO::AIO::munmap $scalar
		1961
		1962	Removes a previous mmap and undefines the C<$scalar>.
		1963
		1964	=item IO::AIO::munlock $scalar, $offset = 0, $length = undef
		1965
		1966	Calls the C<munlock> function, undoing the effects of a previous
		1967	C<aio_mlock> call (see its description for details).
		1968
		1969	=item IO::AIO::munlockall
		1970
		1971	Calls the C<munlockall> function.
		1972
		1973	On systems that do not implement C<munlockall>, this function returns
		1974	ENOSYS, otherwise the return value of C<munlockall>.
		1975
		1976	=item IO::AIO::splice $r_fh, $r_off, $w_fh, $w_off, $length, $flags
		1977
		1978	Calls the GNU/Linux C<splice(2)> syscall, if available. If C<$r_off> or
		1979	C<$w_off> are C<undef>, then C<NULL> is passed for these, otherwise they
		1980	should be the file offset.
		1981
		1982	The following symbol flag values are available: C<IO::AIO::SPLICE_F_MOVE>,
		1983	C<IO::AIO::SPLICE_F_NONBLOCK>, C<IO::AIO::SPLICE_F_MORE> and
		1984	C<IO::AIO::SPLICE_F_GIFT>.
		1985
		1986	See the C<splice(2)> manpage for details.
		1987
		1988	=item IO::AIO::tee $r_fh, $w_fh, $length, $flags
		1989
		1990	Calls the GNU/Linux C<tee(2)> syscall, see it's manpage and the
		1991	description for C<IO::AIO::splice> above for details.
		1992
1460	=back	1993	=back
1461		1994
1462	=cut	1995	=cut
1463		1996
1464	min_parallel 8;	1997	min_parallel 8;
1465		1998
1466	END { flush }	1999	END { flush }
1467		2000
1468	1;	2001	1;
1469		2002
		2003	=head1 EVENT LOOP INTEGRATION
		2004
		2005	It is recommended to use L<AnyEvent::AIO> to integrate IO::AIO
		2006	automatically into many event loops:
		2007
		2008	# AnyEvent integration (EV, Event, Glib, Tk, POE, urxvt, pureperl...)
		2009	use AnyEvent::AIO;
		2010
		2011	You can also integrate IO::AIO manually into many event loops, here are
		2012	some examples of how to do this:
		2013
		2014	# EV integration
		2015	my $aio_w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb;
		2016
		2017	# Event integration
		2018	Event->io (fd => IO::AIO::poll_fileno,
		2019	poll => 'r',
		2020	cb => \&IO::AIO::poll_cb);
		2021
		2022	# Glib/Gtk2 integration
		2023	add_watch Glib::IO IO::AIO::poll_fileno,
		2024	in => sub { IO::AIO::poll_cb; 1 };
		2025
		2026	# Tk integration
		2027	Tk::Event::IO->fileevent (IO::AIO::poll_fileno, "",
		2028	readable => \&IO::AIO::poll_cb);
		2029
		2030	# Danga::Socket integration
		2031	Danga::Socket->AddOtherFds (IO::AIO::poll_fileno =>
		2032	\&IO::AIO::poll_cb);
		2033
1470	=head2 FORK BEHAVIOUR	2034	=head2 FORK BEHAVIOUR
1471		2035
1472	This module should do "the right thing" when the process using it forks:	2036	Usage of pthreads in a program changes the semantics of fork
		2037	considerably. Specifically, only async-safe functions can be called after
		2038	fork. Perl doesn't know about this, so in general, you cannot call fork
		2039	with defined behaviour in perl if pthreads are involved. IO::AIO uses
		2040	pthreads, so this applies, but many other extensions and (for inexplicable
		2041	reasons) perl itself often is linked against pthreads, so this limitation
		2042	applies to quite a lot of perls.
1473		2043
1474	Before the fork, IO::AIO enters a quiescent state where no requests	2044	This module no longer tries to fight your OS, or POSIX. That means IO::AIO
1475	can be added in other threads and no results will be processed. After	2045	only works in the process that loaded it. Forking is fully supported, but
1476	the fork the parent simply leaves the quiescent state and continues	2046	using IO::AIO in the child is not.
1477	request/result processing, while the child frees the request/result queue
1478	(so that the requests started before the fork will only be handled in the
1479	parent). Threads will be started on demand until the limit set in the
1480	parent process has been reached again.
1481		2047
1482	In short: the parent will, after a short pause, continue as if fork had	2048	You might get around by not I<using> IO::AIO before (or after)
1483	not been called, while the child will act as if IO::AIO has not been used	2049	forking. You could also try to call the L<IO::AIO::reinit> function in the
1484	yet.	2050	child:
		2051
		2052	=over 4
		2053
		2054	=item IO::AIO::reinit
		2055
		2056	Abandons all current requests and I/O threads and simply reinitialises all
		2057	data structures. This is not an operation supported by any standards, but
		2058	happens to work on GNU/Linux and some newer BSD systems.
		2059
		2060	The only reasonable use for this function is to call it after forking, if
		2061	C<IO::AIO> was used in the parent. Calling it while IO::AIO is active in
		2062	the process will result in undefined behaviour. Calling it at any time
		2063	will also result in any undefined (by POSIX) behaviour.
		2064
		2065	=back
1485		2066
1486	=head2 MEMORY USAGE	2067	=head2 MEMORY USAGE
1487		2068
1488	Per-request usage:	2069	Per-request usage:
1489		2070

Diff Legend

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

Comparing IO-AIO/AIO.pm (file contents): Revision 1.171 by root, Sat Jan 2 14:24:32 2010 UTC vs. Revision 1.226 by root, Mon May 28 17:00:19 2012 UTC

Diff Legend

Comparing IO-AIO/AIO.pm (file contents):
Revision 1.171 by root, Sat Jan 2 14:24:32 2010 UTC vs.
Revision 1.226 by root, Mon May 28 17:00:19 2012 UTC