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

Comparing IO-AIO/AIO.pm (file contents):
Revision 1.199 by root, Wed Jun 29 12:46:36 2011 UTC vs.
Revision 1.240 by root, Mon Dec 17 06:18:39 2012 UTC

…		…
168	use common::sense;	168	use common::sense;
169		169
170	use base 'Exporter';	170	use base 'Exporter';
171		171
172	BEGIN {	172	BEGIN {
173	our $VERSION = '3.92';	173	our $VERSION = '4.18';
174		174
175	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
176	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
177	aio_scandir aio_symlink aio_readlink aio_sync aio_fsync	177	aio_scandir aio_symlink aio_readlink aio_realpath aio_sync
178	aio_fdatasync aio_sync_file_range aio_pathsync aio_readahead	178	aio_fsync aio_syncfs aio_fdatasync aio_sync_file_range aio_allocate
		179	aio_pathsync aio_readahead aio_fiemap
179	aio_rename aio_link aio_move aio_copy aio_group	180	aio_rename aio_link aio_move aio_copy aio_group
180	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
181	aio_chmod aio_utime aio_truncate	182	aio_chmod aio_utime aio_truncate
182	aio_msync aio_mtouch aio_mlock aio_mlockall	183	aio_msync aio_mtouch aio_mlock aio_mlockall
183	aio_statvfs);	184	aio_statvfs
		185	aio_wd);
184		186
185	our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice));	187	our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice));
186	our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush	188	our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush
187	min_parallel max_parallel max_idle idle_timeout	189	min_parallel max_parallel max_idle idle_timeout
188	nreqs nready npending nthreads	190	nreqs nready npending nthreads
…		…
200		202
201	=head1 FUNCTIONS	203	=head1 FUNCTIONS
202		204
203	=head2 QUICK OVERVIEW	205	=head2 QUICK OVERVIEW
204		206
205	This section simply lists the prototypes of the most important functions	207	This section simply lists the prototypes most of the functions for
206	for quick reference. See the following sections for function-by-function	208	quick reference. See the following sections for function-by-function
207	documentation.	209	documentation.
208		210
		211	aio_wd $pathname, $callback->($wd)
209	aio_open $pathname, $flags, $mode, $callback->($fh)	212	aio_open $pathname, $flags, $mode, $callback->($fh)
210	aio_close $fh, $callback->($status)	213	aio_close $fh, $callback->($status)
		214	aio_seek $fh,$offset,$whence, $callback->($offs)
211	aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)	215	aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
212	aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)	216	aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
213	aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval)	217	aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval)
214	aio_readahead $fh,$offset,$length, $callback->($retval)	218	aio_readahead $fh,$offset,$length, $callback->($retval)
215	aio_stat $fh_or_path, $callback->($status)	219	aio_stat $fh_or_path, $callback->($status)
216	aio_lstat $fh, $callback->($status)	220	aio_lstat $fh, $callback->($status)
217	aio_statvfs $fh_or_path, $callback->($statvfs)	221	aio_statvfs $fh_or_path, $callback->($statvfs)
218	aio_utime $fh_or_path, $atime, $mtime, $callback->($status)	222	aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
219	aio_chown $fh_or_path, $uid, $gid, $callback->($status)	223	aio_chown $fh_or_path, $uid, $gid, $callback->($status)
		224	aio_chmod $fh_or_path, $mode, $callback->($status)
220	aio_truncate $fh_or_path, $offset, $callback->($status)	225	aio_truncate $fh_or_path, $offset, $callback->($status)
221	aio_chmod $fh_or_path, $mode, $callback->($status)	226	aio_allocate $fh, $mode, $offset, $len, $callback->($status)
		227	aio_fiemap $fh, $start, $length, $flags, $count, $cb->(\@extents)
222	aio_unlink $pathname, $callback->($status)	228	aio_unlink $pathname, $callback->($status)
223	aio_mknod $path, $mode, $dev, $callback->($status)	229	aio_mknod $pathname, $mode, $dev, $callback->($status)
224	aio_link $srcpath, $dstpath, $callback->($status)	230	aio_link $srcpath, $dstpath, $callback->($status)
225	aio_symlink $srcpath, $dstpath, $callback->($status)	231	aio_symlink $srcpath, $dstpath, $callback->($status)
226	aio_readlink $path, $callback->($link)	232	aio_readlink $pathname, $callback->($link)
		233	aio_realpath $pathname, $callback->($link)
227	aio_rename $srcpath, $dstpath, $callback->($status)	234	aio_rename $srcpath, $dstpath, $callback->($status)
228	aio_mkdir $pathname, $mode, $callback->($status)	235	aio_mkdir $pathname, $mode, $callback->($status)
229	aio_rmdir $pathname, $callback->($status)	236	aio_rmdir $pathname, $callback->($status)
230	aio_readdir $pathname, $callback->($entries)	237	aio_readdir $pathname, $callback->($entries)
231	aio_readdirx $pathname, $flags, $callback->($entries, $flags)	238	aio_readdirx $pathname, $flags, $callback->($entries, $flags)
232	IO::AIO::READDIR_DENTS IO::AIO::READDIR_DIRS_FIRST	239	IO::AIO::READDIR_DENTS IO::AIO::READDIR_DIRS_FIRST
233	IO::AIO::READDIR_STAT_ORDER IO::AIO::READDIR_FOUND_UNKNOWN	240	IO::AIO::READDIR_STAT_ORDER IO::AIO::READDIR_FOUND_UNKNOWN
		241	aio_scandir $pathname, $maxreq, $callback->($dirs, $nondirs)
234	aio_load $path, $data, $callback->($status)	242	aio_load $pathname, $data, $callback->($status)
235	aio_copy $srcpath, $dstpath, $callback->($status)	243	aio_copy $srcpath, $dstpath, $callback->($status)
236	aio_move $srcpath, $dstpath, $callback->($status)	244	aio_move $srcpath, $dstpath, $callback->($status)
237	aio_scandir $path, $maxreq, $callback->($dirs, $nondirs)
238	aio_rmtree $path, $callback->($status)	245	aio_rmtree $pathname, $callback->($status)
239	aio_sync $callback->($status)	246	aio_sync $callback->($status)
		247	aio_syncfs $fh, $callback->($status)
240	aio_fsync $fh, $callback->($status)	248	aio_fsync $fh, $callback->($status)
241	aio_fdatasync $fh, $callback->($status)	249	aio_fdatasync $fh, $callback->($status)
242	aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status)	250	aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status)
243	aio_pathsync $path, $callback->($status)	251	aio_pathsync $pathname, $callback->($status)
244	aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)	252	aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
245	aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)	253	aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
246	aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status)	254	aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status)
247	aio_mlockall $flags, $callback->($status)	255	aio_mlockall $flags, $callback->($status)
248	aio_group $callback->(...)	256	aio_group $callback->(...)
…		…
266	IO::AIO::nready	274	IO::AIO::nready
267	IO::AIO::npending	275	IO::AIO::npending
268		276
269	IO::AIO::sendfile $ofh, $ifh, $offset, $count	277	IO::AIO::sendfile $ofh, $ifh, $offset, $count
270	IO::AIO::fadvise $fh, $offset, $len, $advice	278	IO::AIO::fadvise $fh, $offset, $len, $advice
		279	IO::AIO::mmap $scalar, $length, $prot, $flags[, $fh[, $offset]]
		280	IO::AIO::munmap $scalar
271	IO::AIO::madvise $scalar, $offset, $length, $advice	281	IO::AIO::madvise $scalar, $offset, $length, $advice
272	IO::AIO::mprotect $scalar, $offset, $length, $protect	282	IO::AIO::mprotect $scalar, $offset, $length, $protect
273	IO::AIO::munlock $scalar, $offset = 0, $length = undef	283	IO::AIO::munlock $scalar, $offset = 0, $length = undef
274	IO::AIO::munlockall	284	IO::AIO::munlockall
275		285
276	=head2 AIO REQUEST FUNCTIONS	286	=head2 API NOTES
277		287
278	All the C<aio_*> calls are more or less thin wrappers around the syscall	288	All the C<aio_*> calls are more or less thin wrappers around the syscall
279	with the same name (sans C<aio_>). The arguments are similar or identical,	289	with the same name (sans C<aio_>). The arguments are similar or identical,
280	and they all accept an additional (and optional) C<$callback> argument	290	and they all accept an additional (and optional) C<$callback> argument
281	which must be a code reference. This code reference will get called with	291	which must be a code reference. This code reference will be called after
282	the syscall return code (e.g. most syscalls return C<-1> on error, unlike	292	the syscall has been executed in an asynchronous fashion. The results
283	perl, which usually delivers "false") as its sole argument after the given	293	of the request will be passed as arguments to the callback (and, if an
284	syscall has been executed asynchronously.	294	error occured, in C<$!>) - for most requests the syscall return code (e.g.
		295	most syscalls return C<-1> on error, unlike perl, which usually delivers
		296	"false").
		297
		298	Some requests (such as C<aio_readdir>) pass the actual results and
		299	communicate failures by passing C<undef>.
285		300
286	All functions expecting a filehandle keep a copy of the filehandle	301	All functions expecting a filehandle keep a copy of the filehandle
287	internally until the request has finished.	302	internally until the request has finished.
288		303
289	All functions return request objects of type L<IO::AIO::REQ> that allow	304	All functions return request objects of type L<IO::AIO::REQ> that allow
290	further manipulation of those requests while they are in-flight.	305	further manipulation of those requests while they are in-flight.
291		306
292	The pathnames you pass to these routines I<must> be absolute and	307	The pathnames you pass to these routines I<should> be absolute. The
293	encoded as octets. The reason for the former is that at the time the	308	reason for this is that at the time the request is being executed, the
294	request is being executed, the current working directory could have	309	current working directory could have changed. Alternatively, you can
295	changed. Alternatively, you can make sure that you never change the	310	make sure that you never change the current working directory anywhere
296	current working directory anywhere in the program and then use relative	311	in the program and then use relative paths. You can also take advantage
297	paths.	312	of IO::AIOs working directory abstraction, that lets you specify paths
		313	relative to some previously-opened "working directory object" - see the
		314	description of the C<IO::AIO::WD> class later in this document.
298		315
299	To encode pathnames as octets, either make sure you either: a) always pass	316	To encode pathnames as octets, either make sure you either: a) always pass
300	in filenames you got from outside (command line, readdir etc.) without	317	in filenames you got from outside (command line, readdir etc.) without
301	tinkering, b) are ASCII or ISO 8859-1, c) use the Encode module and encode	318	tinkering, b) are in your native filesystem encoding, c) use the Encode
302	your pathnames to the locale (or other) encoding in effect in the user	319	module and encode your pathnames to the locale (or other) encoding in
303	environment, d) use Glib::filename_from_unicode on unicode filenames or e)	320	effect in the user environment, d) use Glib::filename_from_unicode on
304	use something else to ensure your scalar has the correct contents.	321	unicode filenames or e) use something else to ensure your scalar has the
		322	correct contents.
305		323
306	This works, btw. independent of the internal UTF-8 bit, which IO::AIO	324	This works, btw. independent of the internal UTF-8 bit, which IO::AIO
307	handles correctly whether it is set or not.	325	handles correctly whether it is set or not.
		326
		327	=head2 AIO REQUEST FUNCTIONS
308		328
309	=over 4	329	=over 4
310		330
311	=item $prev_pri = aioreq_pri [$pri]	331	=item $prev_pri = aioreq_pri [$pri]
312		332
…		…
342		362
343		363
344	=item aio_open $pathname, $flags, $mode, $callback->($fh)	364	=item aio_open $pathname, $flags, $mode, $callback->($fh)
345		365
346	Asynchronously open or create a file and call the callback with a newly	366	Asynchronously open or create a file and call the callback with a newly
347	created filehandle for the file.	367	created filehandle for the file (or C<undef> in case of an error).
348		368
349	The pathname passed to C<aio_open> must be absolute. See API NOTES, above,	369	The pathname passed to C<aio_open> must be absolute. See API NOTES, above,
350	for an explanation.	370	for an explanation.
351		371
352	The C<$flags> argument is a bitmask. See the C<Fcntl> module for a	372	The C<$flags> argument is a bitmask. See the C<Fcntl> module for a
…		…
394		414
395	Or in other words: the file descriptor will be closed, but it will not be	415	Or in other words: the file descriptor will be closed, but it will not be
396	free for reuse until the perl filehandle is closed.	416	free for reuse until the perl filehandle is closed.
397		417
398	=cut	418	=cut
		419
		420	=item aio_seek $fh, $offset, $whence, $callback->($offs)
		421
		422	Seeks the filehandle to the new C<$offset>, similarly to perl's
		423	C<sysseek>. The C<$whence> can use the traditional values (C<0> for
		424	C<IO::AIO::SEEK_SET>, C<1> for C<IO::AIO::SEEK_CUR> or C<2> for
		425	C<IO::AIO::SEEK_END>).
		426
		427	The resulting absolute offset will be passed to the callback, or C<-1> in
		428	case of an error.
		429
		430	In theory, the C<$whence> constants could be different than the
		431	corresponding values from L<Fcntl>, but perl guarantees they are the same,
		432	so don't panic.
		433
		434	As a GNU/Linux (and maybe Solaris) extension, also the constants
		435	C<IO::AIO::SEEK_DATA> and C<IO::AIO::SEEK_HOLE> are available, if they
		436	could be found. No guarantees about suitability for use in C<aio_seek> or
		437	Perl's C<sysseek> can be made though, although I would naively assume they
		438	"just work".
399		439
400	=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)	440	=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
401		441
402	=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)	442	=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
403		443
…		…
563	namemax => 255,	603	namemax => 255,
564	frsize => 1024,	604	frsize => 1024,
565	fsid => 1810	605	fsid => 1810
566	}	606	}
567		607
		608	Here is a (likely partial) list of fsid values used by Linux - it is safe
		609	to hardcode these when the $^O is C<linux>:
		610
		611	0x0000adf5 adfs
		612	0x0000adff affs
		613	0x5346414f afs
		614	0x09041934 anon-inode filesystem
		615	0x00000187 autofs
		616	0x42465331 befs
		617	0x1badface bfs
		618	0x42494e4d binfmt_misc
		619	0x9123683e btrfs
		620	0x0027e0eb cgroupfs
		621	0xff534d42 cifs
		622	0x73757245 coda
		623	0x012ff7b7 coh
		624	0x28cd3d45 cramfs
		625	0x453dcd28 cramfs-wend (wrong endianness)
		626	0x64626720 debugfs
		627	0x00001373 devfs
		628	0x00001cd1 devpts
		629	0x0000f15f ecryptfs
		630	0x00414a53 efs
		631	0x0000137d ext
		632	0x0000ef53 ext2/ext3
		633	0x0000ef51 ext2
		634	0x00004006 fat
		635	0x65735546 fuseblk
		636	0x65735543 fusectl
		637	0x0bad1dea futexfs
		638	0x01161970 gfs2
		639	0x47504653 gpfs
		640	0x00004244 hfs
		641	0xf995e849 hpfs
		642	0x958458f6 hugetlbfs
		643	0x2bad1dea inotifyfs
		644	0x00009660 isofs
		645	0x000072b6 jffs2
		646	0x3153464a jfs
		647	0x6b414653 k-afs
		648	0x0bd00bd0 lustre
		649	0x0000137f minix
		650	0x0000138f minix 30 char names
		651	0x00002468 minix v2
		652	0x00002478 minix v2 30 char names
		653	0x00004d5a minix v3
		654	0x19800202 mqueue
		655	0x00004d44 msdos
		656	0x0000564c novell
		657	0x00006969 nfs
		658	0x6e667364 nfsd
		659	0x00003434 nilfs
		660	0x5346544e ntfs
		661	0x00009fa1 openprom
		662	0x7461636F ocfs2
		663	0x00009fa0 proc
		664	0x6165676c pstorefs
		665	0x0000002f qnx4
		666	0x858458f6 ramfs
		667	0x52654973 reiserfs
		668	0x00007275 romfs
		669	0x67596969 rpc_pipefs
		670	0x73636673 securityfs
		671	0xf97cff8c selinux
		672	0x0000517b smb
		673	0x534f434b sockfs
		674	0x73717368 squashfs
		675	0x62656572 sysfs
		676	0x012ff7b6 sysv2
		677	0x012ff7b5 sysv4
		678	0x01021994 tmpfs
		679	0x15013346 udf
		680	0x00011954 ufs
		681	0x54190100 ufs byteswapped
		682	0x00009fa2 usbdevfs
		683	0x01021997 v9fs
		684	0xa501fcf5 vxfs
		685	0xabba1974 xenfs
		686	0x012ff7b4 xenix
		687	0x58465342 xfs
		688	0x012fd16d xia
568		689
569	=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status)	690	=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
570		691
571	Works like perl's C<utime> function (including the special case of $atime	692	Works like perl's C<utime> function (including the special case of $atime
572	and $mtime being undef). Fractional times are supported if the underlying	693	and $mtime being undef). Fractional times are supported if the underlying
…		…
600	=item aio_truncate $fh_or_path, $offset, $callback->($status)	721	=item aio_truncate $fh_or_path, $offset, $callback->($status)
601		722
602	Works like truncate(2) or ftruncate(2).	723	Works like truncate(2) or ftruncate(2).
603		724
604		725
		726	=item aio_allocate $fh, $mode, $offset, $len, $callback->($status)
		727
		728	Allocates or freed disk space according to the C<$mode> argument. See the
		729	linux C<fallocate> docuemntation for details.
		730
		731	C<$mode> can currently be C<0> or C<IO::AIO::FALLOC_FL_KEEP_SIZE>
		732	to allocate space, or C<IO::AIO::FALLOC_FL_PUNCH_HOLE \|
		733	IO::AIO::FALLOC_FL_KEEP_SIZE>, to deallocate a file range.
		734
		735	The file system block size used by C<fallocate> is presumably the
		736	C<f_bsize> returned by C<statvfs>.
		737
		738	If C<fallocate> isn't available or cannot be emulated (currently no
		739	emulation will be attempted), passes C<-1> and sets C<$!> to C<ENOSYS>.
		740
		741
605	=item aio_chmod $fh_or_path, $mode, $callback->($status)	742	=item aio_chmod $fh_or_path, $mode, $callback->($status)
606		743
607	Works like perl's C<chmod> function.	744	Works like perl's C<chmod> function.
608		745
609		746
…		…
611		748
612	Asynchronously unlink (delete) a file and call the callback with the	749	Asynchronously unlink (delete) a file and call the callback with the
613	result code.	750	result code.
614		751
615		752
616	=item aio_mknod $path, $mode, $dev, $callback->($status)	753	=item aio_mknod $pathname, $mode, $dev, $callback->($status)
617		754
618	[EXPERIMENTAL]	755	[EXPERIMENTAL]
619		756
620	Asynchronously create a device node (or fifo). See mknod(2).	757	Asynchronously create a device node (or fifo). See mknod(2).
621		758
622	The only (POSIX-) portable way of calling this function is:	759	The only (POSIX-) portable way of calling this function is:
623		760
624	aio_mknod $path, IO::AIO::S_IFIFO \| $mode, 0, sub { ...	761	aio_mknod $pathname, IO::AIO::S_IFIFO \| $mode, 0, sub { ...
625		762
626	See C<aio_stat> for info about some potentially helpful extra constants	763	See C<aio_stat> for info about some potentially helpful extra constants
627	and functions.	764	and functions.
628		765
629	=item aio_link $srcpath, $dstpath, $callback->($status)	766	=item aio_link $srcpath, $dstpath, $callback->($status)
…		…
636		773
637	Asynchronously create a new symbolic link to the existing object at C<$srcpath> at	774	Asynchronously create a new symbolic link to the existing object at C<$srcpath> at
638	the path C<$dstpath> and call the callback with the result code.	775	the path C<$dstpath> and call the callback with the result code.
639		776
640		777
641	=item aio_readlink $path, $callback->($link)	778	=item aio_readlink $pathname, $callback->($link)
642		779
643	Asynchronously read the symlink specified by C<$path> and pass it to	780	Asynchronously read the symlink specified by C<$path> and pass it to
644	the callback. If an error occurs, nothing or undef gets passed to the	781	the callback. If an error occurs, nothing or undef gets passed to the
645	callback.	782	callback.
646		783
647		784
		785	=item aio_realpath $pathname, $callback->($path)
		786
		787	Asynchronously make the path absolute and resolve any symlinks in
		788	C<$path>. The resulting path only consists of directories (same as
		789	L<Cwd::realpath>).
		790
		791	This request can be used to get the absolute path of the current working
		792	directory by passing it a path of F<.> (a single dot).
		793
		794
648	=item aio_rename $srcpath, $dstpath, $callback->($status)	795	=item aio_rename $srcpath, $dstpath, $callback->($status)
649		796
650	Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as	797	Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as
651	rename(2) and call the callback with the result code.	798	rename(2) and call the callback with the result code.
652		799
…		…
674	array-ref with the filenames.	821	array-ref with the filenames.
675		822
676		823
677	=item aio_readdirx $pathname, $flags, $callback->($entries, $flags)	824	=item aio_readdirx $pathname, $flags, $callback->($entries, $flags)
678		825
679	Quite similar to C<aio_readdir>, but the C<$flags> argument allows to tune	826	Quite similar to C<aio_readdir>, but the C<$flags> argument allows one to
680	behaviour and output format. In case of an error, C<$entries> will be	827	tune behaviour and output format. In case of an error, C<$entries> will be
681	C<undef>.	828	C<undef>.
682		829
683	The flags are a combination of the following constants, ORed together (the	830	The flags are a combination of the following constants, ORed together (the
684	flags will also be passed to the callback, possibly modified):	831	flags will also be passed to the callback, possibly modified):
685		832
…		…
732		879
733	=item IO::AIO::READDIR_FOUND_UNKNOWN	880	=item IO::AIO::READDIR_FOUND_UNKNOWN
734		881
735	This flag should not be set when calling C<aio_readdirx>. Instead, it	882	This flag should not be set when calling C<aio_readdirx>. Instead, it
736	is being set by C<aio_readdirx>, when any of the C<$type>'s found were	883	is being set by C<aio_readdirx>, when any of the C<$type>'s found were
737	C<IO::AIO::DT_UNKNOWN>. The absense of this flag therefore indicates that all	884	C<IO::AIO::DT_UNKNOWN>. The absence of this flag therefore indicates that all
738	C<$type>'s are known, which can be used to speed up some algorithms.	885	C<$type>'s are known, which can be used to speed up some algorithms.
739		886
740	=back	887	=back
741		888
742		889
743	=item aio_load $path, $data, $callback->($status)	890	=item aio_load $pathname, $data, $callback->($status)
744		891
745	This is a composite request that tries to fully load the given file into	892	This is a composite request that tries to fully load the given file into
746	memory. Status is the same as with aio_read.	893	memory. Status is the same as with aio_read.
747		894
748	=cut	895	=cut
…		…
883	};	1030	};
884		1031
885	$grp	1032	$grp
886	}	1033	}
887		1034
888	=item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs)	1035	=item aio_scandir $pathname, $maxreq, $callback->($dirs, $nondirs)
889		1036
890	Scans a directory (similar to C<aio_readdir>) but additionally tries to	1037	Scans a directory (similar to C<aio_readdir>) but additionally tries to
891	efficiently separate the entries of directory C<$path> into two sets of	1038	efficiently separate the entries of directory C<$path> into two sets of
892	names, directories you can recurse into (directories), and ones you cannot	1039	names, directories you can recurse into (directories), and ones you cannot
893	recurse into (everything else, including symlinks to directories).	1040	recurse into (everything else, including symlinks to directories).
…		…
924	Then entries will be sorted into likely directories a non-initial dot	1071	Then entries will be sorted into likely directories a non-initial dot
925	currently) and likely non-directories (see C<aio_readdirx>). Then every	1072	currently) and likely non-directories (see C<aio_readdirx>). Then every
926	entry plus an appended C</.> will be C<stat>'ed, likely directories first,	1073	entry plus an appended C</.> will be C<stat>'ed, likely directories first,
927	in order of their inode numbers. If that succeeds, it assumes that the	1074	in order of their inode numbers. If that succeeds, it assumes that the
928	entry is a directory or a symlink to directory (which will be checked	1075	entry is a directory or a symlink to directory (which will be checked
929	seperately). This is often faster than stat'ing the entry itself because	1076	separately). This is often faster than stat'ing the entry itself because
930	filesystems might detect the type of the entry without reading the inode	1077	filesystems might detect the type of the entry without reading the inode
931	data (e.g. ext2fs filetype feature), even on systems that cannot return	1078	data (e.g. ext2fs filetype feature), even on systems that cannot return
932	the filetype information on readdir.	1079	the filetype information on readdir.
933		1080
934	If the known number of directories (link count - 2) has been reached, the	1081	If the known number of directories (link count - 2) has been reached, the
…		…
950		1097
951	my $grp = aio_group $cb;	1098	my $grp = aio_group $cb;
952		1099
953	$maxreq = 4 if $maxreq <= 0;	1100	$maxreq = 4 if $maxreq <= 0;
954		1101
955	# stat once	1102	# get a wd object
956	aioreq_pri $pri;	1103	aioreq_pri $pri;
957	add $grp aio_stat $path, sub {	1104	add $grp aio_wd $path, sub {
		1105	$_[0]
958	return $grp->result () if $_[0];	1106	or return $grp->result ();
959	my $now = time;
960	my $hash1 = join ":", (stat _)[0,1,3,7,9];
961		1107
962	# read the directory entries	1108	my $wd = [shift, "."];
		1109
		1110	# stat once
963	aioreq_pri $pri;	1111	aioreq_pri $pri;
964	add $grp aio_readdirx $path, READDIR_DIRS_FIRST, sub {	1112	add $grp aio_stat $wd, sub {
965	my $entries = shift
966	or return $grp->result ();	1113	return $grp->result () if $_[0];
		1114	my $now = time;
		1115	my $hash1 = join ":", (stat _)[0,1,3,7,9];
967		1116
968	# stat the dir another time	1117	# read the directory entries
969	aioreq_pri $pri;	1118	aioreq_pri $pri;
		1119	add $grp aio_readdirx $wd, READDIR_DIRS_FIRST, sub {
		1120	my $entries = shift
		1121	or return $grp->result ();
		1122
		1123	# stat the dir another time
		1124	aioreq_pri $pri;
970	add $grp aio_stat $path, sub {	1125	add $grp aio_stat $wd, sub {
971	my $hash2 = join ":", (stat _)[0,1,3,7,9];	1126	my $hash2 = join ":", (stat _)[0,1,3,7,9];
972		1127
973	my $ndirs;	1128	my $ndirs;
974		1129
975	# take the slow route if anything looks fishy	1130	# take the slow route if anything looks fishy
976	if ($hash1 ne $hash2 or (stat _)[9] == $now) {	1131	if ($hash1 ne $hash2 or (stat _)[9] == $now) {
977	$ndirs = -1;	1132	$ndirs = -1;
978	} else {	1133	} else {
979	# if nlink == 2, we are finished	1134	# if nlink == 2, we are finished
980	# for non-posix-fs's, we rely on nlink < 2	1135	# for non-posix-fs's, we rely on nlink < 2
981	$ndirs = (stat _)[3] - 2	1136	$ndirs = (stat _)[3] - 2
982	or return $grp->result ([], $entries);	1137	or return $grp->result ([], $entries);
983	}	1138	}
984		1139
985	my (@dirs, @nondirs);	1140	my (@dirs, @nondirs);
986		1141
987	my $statgrp = add $grp aio_group sub {	1142	my $statgrp = add $grp aio_group sub {
988	$grp->result (\@dirs, \@nondirs);	1143	$grp->result (\@dirs, \@nondirs);
989	};	1144	};
990		1145
991	limit $statgrp $maxreq;	1146	limit $statgrp $maxreq;
992	feed $statgrp sub {	1147	feed $statgrp sub {
993	return unless @$entries;	1148	return unless @$entries;
994	my $entry = shift @$entries;	1149	my $entry = shift @$entries;
995		1150
996	aioreq_pri $pri;	1151	aioreq_pri $pri;
		1152	$wd->[1] = "$entry/.";
997	add $statgrp aio_stat "$path/$entry/.", sub {	1153	add $statgrp aio_stat $wd, sub {
998	if ($_[0] < 0) {	1154	if ($_[0] < 0) {
999	push @nondirs, $entry;	1155	push @nondirs, $entry;
1000	} else {	1156	} else {
1001	# need to check for real directory	1157	# need to check for real directory
1002	aioreq_pri $pri;	1158	aioreq_pri $pri;
		1159	$wd->[1] = $entry;
1003	add $statgrp aio_lstat "$path/$entry", sub {	1160	add $statgrp aio_lstat $wd, sub {
1004	if (-d _) {	1161	if (-d _) {
1005	push @dirs, $entry;	1162	push @dirs, $entry;
1006		1163
1007	unless (--$ndirs) {	1164	unless (--$ndirs) {
1008	push @nondirs, @$entries;	1165	push @nondirs, @$entries;
1009	feed $statgrp;	1166	feed $statgrp;
		1167	}
		1168	} else {
		1169	push @nondirs, $entry;
1010	}	1170	}
1011	} else {
1012	push @nondirs, $entry;
1013	}	1171	}
1014	}	1172	}
1015	}	1173	};
1016	};	1174	};
1017	};	1175	};
1018	};	1176	};
1019	};	1177	};
1020	};	1178	};
1021		1179
1022	$grp	1180	$grp
1023	}	1181	}
1024		1182
1025	=item aio_rmtree $path, $callback->($status)	1183	=item aio_rmtree $pathname, $callback->($status)
1026		1184
1027	Delete a directory tree starting (and including) C<$path>, return the	1185	Delete a directory tree starting (and including) C<$path>, return the
1028	status of the final C<rmdir> only. This is a composite request that	1186	status of the final C<rmdir> only. This is a composite request that
1029	uses C<aio_scandir> to recurse into and rmdir directories, and unlink	1187	uses C<aio_scandir> to recurse into and rmdir directories, and unlink
1030	everything else.	1188	everything else.
1031		1189
1032	=cut	1190	=cut
1033		1191
…		…
1072	callback with the fdatasync result code.	1230	callback with the fdatasync result code.
1073		1231
1074	If this call isn't available because your OS lacks it or it couldn't be	1232	If this call isn't available because your OS lacks it or it couldn't be
1075	detected, it will be emulated by calling C<fsync> instead.	1233	detected, it will be emulated by calling C<fsync> instead.
1076		1234
		1235	=item aio_syncfs $fh, $callback->($status)
		1236
		1237	Asynchronously call the syncfs syscall to sync the filesystem associated
		1238	to the given filehandle and call the callback with the syncfs result
		1239	code. If syncfs is not available, calls sync(), but returns C<-1> and sets
		1240	errno to C<ENOSYS> nevertheless.
		1241
1077	=item aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status)	1242	=item aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status)
1078		1243
1079	Sync the data portion of the file specified by C<$offset> and C<$length>	1244	Sync the data portion of the file specified by C<$offset> and C<$length>
1080	to disk (but NOT the metadata), by calling the Linux-specific	1245	to disk (but NOT the metadata), by calling the Linux-specific
1081	sync_file_range call. If sync_file_range is not available or it returns	1246	sync_file_range call. If sync_file_range is not available or it returns
…		…
1084	C<$flags> can be a combination of C<IO::AIO::SYNC_FILE_RANGE_WAIT_BEFORE>,	1249	C<$flags> can be a combination of C<IO::AIO::SYNC_FILE_RANGE_WAIT_BEFORE>,
1085	C<IO::AIO::SYNC_FILE_RANGE_WRITE> and	1250	C<IO::AIO::SYNC_FILE_RANGE_WRITE> and
1086	C<IO::AIO::SYNC_FILE_RANGE_WAIT_AFTER>: refer to the sync_file_range	1251	C<IO::AIO::SYNC_FILE_RANGE_WAIT_AFTER>: refer to the sync_file_range
1087	manpage for details.	1252	manpage for details.
1088		1253
1089	=item aio_pathsync $path, $callback->($status)	1254	=item aio_pathsync $pathname, $callback->($status)
1090		1255
1091	This request tries to open, fsync and close the given path. This is a	1256	This request tries to open, fsync and close the given path. This is a
1092	composite request intended to sync directories after directory operations	1257	composite request intended to sync directories after directory operations
1093	(E.g. rename). This might not work on all operating systems or have any	1258	(E.g. rename). This might not work on all operating systems or have any
1094	specific effect, but usually it makes sure that directory changes get	1259	specific effect, but usually it makes sure that directory changes get
…		…
1146		1311
1147	This is a rather advanced IO::AIO call, which works best on mmap(2)ed	1312	This is a rather advanced IO::AIO call, which works best on mmap(2)ed
1148	scalars.	1313	scalars.
1149		1314
1150	It touches (reads or writes) all memory pages in the specified	1315	It touches (reads or writes) all memory pages in the specified
1151	range inside the scalar. All caveats and parameters are the same	1316	range inside the scalar. All caveats and parameters are the same
1152	as for C<aio_msync>, above, except for flags, which must be either	1317	as for C<aio_msync>, above, except for flags, which must be either
1153	C<0> (which reads all pages and ensures they are instantiated) or	1318	C<0> (which reads all pages and ensures they are instantiated) or
1154	C<IO::AIO::MT_MODIFY>, which modifies the memory page s(by reading and	1319	C<IO::AIO::MT_MODIFY>, which modifies the memory pages (by reading and
1155	writing an octet from it, which dirties the page).	1320	writing an octet from it, which dirties the page).
1156		1321
1157	=item aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status)	1322	=item aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status)
1158		1323
1159	This is a rather advanced IO::AIO call, which works best on mmap(2)ed	1324	This is a rather advanced IO::AIO call, which works best on mmap(2)ed
…		…
1190	documented under L<MISCELLANEOUS FUNCTIONS>.	1355	documented under L<MISCELLANEOUS FUNCTIONS>.
1191		1356
1192	Example: asynchronously lock all current and future pages into memory.	1357	Example: asynchronously lock all current and future pages into memory.
1193		1358
1194	aio_mlockall IO::AIO::MCL_FUTURE;	1359	aio_mlockall IO::AIO::MCL_FUTURE;
		1360
		1361	=item aio_fiemap $fh, $start, $length, $flags, $count, $cb->(\@extents)
		1362
		1363	Queries the extents of the given file (by calling the Linux C<FIEMAP>
		1364	ioctl, see L<http://cvs.schmorp.de/IO-AIO/doc/fiemap.txt> for details). If
		1365	the ioctl is not available on your OS, then this request will fail with
		1366	C<ENOSYS>.
		1367
		1368	C<$start> is the starting offset to query extents for, C<$length> is the
		1369	size of the range to query - if it is C<undef>, then the whole file will
		1370	be queried.
		1371
		1372	C<$flags> is a combination of flags (C<IO::AIO::FIEMAP_FLAG_SYNC> or
		1373	C<IO::AIO::FIEMAP_FLAG_XATTR> - C<IO::AIO::FIEMAP_FLAGS_COMPAT> is also
		1374	exported), and is normally C<0> or C<IO::AIO::FIEMAP_FLAG_SYNC> to query
		1375	the data portion.
		1376
		1377	C<$count> is the maximum number of extent records to return. If it is
		1378	C<undef>, then IO::AIO queries all extents of the range. As a very special
		1379	case, if it is C<0>, then the callback receives the number of extents
		1380	instead of the extents themselves (which is unreliable, see below).
		1381
		1382	If an error occurs, the callback receives no arguments. The special
		1383	C<errno> value C<IO::AIO::EBADR> is available to test for flag errors.
		1384
		1385	Otherwise, the callback receives an array reference with extent
		1386	structures. Each extent structure is an array reference itself, with the
		1387	following members:
		1388
		1389	[$logical, $physical, $length, $flags]
		1390
		1391	Flags is any combination of the following flag values (typically either C<0>
		1392	or C<IO::AIO::FIEMAP_EXTENT_LAST> (1)):
		1393
		1394	C<IO::AIO::FIEMAP_EXTENT_LAST>, C<IO::AIO::FIEMAP_EXTENT_UNKNOWN>,
		1395	C<IO::AIO::FIEMAP_EXTENT_DELALLOC>, C<IO::AIO::FIEMAP_EXTENT_ENCODED>,
		1396	C<IO::AIO::FIEMAP_EXTENT_DATA_ENCRYPTED>, C<IO::AIO::FIEMAP_EXTENT_NOT_ALIGNED>,
		1397	C<IO::AIO::FIEMAP_EXTENT_DATA_INLINE>, C<IO::AIO::FIEMAP_EXTENT_DATA_TAIL>,
		1398	C<IO::AIO::FIEMAP_EXTENT_UNWRITTEN>, C<IO::AIO::FIEMAP_EXTENT_MERGED> or
		1399	C<IO::AIO::FIEMAP_EXTENT_SHARED>.
		1400
		1401	At the time of this writing (Linux 3.2), this requets is unreliable unless
		1402	C<$count> is C<undef>, as the kernel has all sorts of bugs preventing
		1403	it to return all extents of a range for files with large number of
		1404	extents. The code works around all these issues if C<$count> is undef.
1195		1405
1196	=item aio_group $callback->(...)	1406	=item aio_group $callback->(...)
1197		1407
1198	This is a very special aio request: Instead of doing something, it is a	1408	This is a very special aio request: Instead of doing something, it is a
1199	container for other aio requests, which is useful if you want to bundle	1409	container for other aio requests, which is useful if you want to bundle
…		…
1236	like sleep and file handle readable/writable, the overhead this creates is	1446	like sleep and file handle readable/writable, the overhead this creates is
1237	immense (it blocks a thread for a long time) so do not use this function	1447	immense (it blocks a thread for a long time) so do not use this function
1238	except to put your application under artificial I/O pressure.	1448	except to put your application under artificial I/O pressure.
1239		1449
1240	=back	1450	=back
		1451
		1452
		1453	=head2 IO::AIO::WD - multiple working directories
		1454
		1455	Your process only has one current working directory, which is used by all
		1456	threads. This makes it hard to use relative paths (some other component
		1457	could call C<chdir> at any time, and it is hard to control when the path
		1458	will be used by IO::AIO).
		1459
		1460	One solution for this is to always use absolute paths. This usually works,
		1461	but can be quite slow (the kernel has to walk the whole path on every
		1462	access), and can also be a hassle to implement.
		1463
		1464	Newer POSIX systems have a number of functions (openat, fdopendir,
		1465	futimensat and so on) that make it possible to specify working directories
		1466	per operation.
		1467
		1468	For portability, and because the clowns who "designed", or shall I write,
		1469	perpetrated this new interface were obviously half-drunk, this abstraction
		1470	cannot be perfect, though.
		1471
		1472	IO::AIO allows you to convert directory paths into a so-called IO::AIO::WD
		1473	object. This object stores the canonicalised, absolute version of the
		1474	path, and on systems that allow it, also a directory file descriptor.
		1475
		1476	Everywhere where a pathname is accepted by IO::AIO (e.g. in C<aio_stat>
		1477	or C<aio_unlink>), one can specify an array reference with an IO::AIO::WD
		1478	object and a pathname instead (or the IO::AIO::WD object alone, which
		1479	gets interpreted as C<[$wd, "."]>). If the pathname is absolute, the
		1480	IO::AIO::WD object is ignored, otherwise the pathname is resolved relative
		1481	to that IO::AIO::WD object.
		1482
		1483	For example, to get a wd object for F</etc> and then stat F<passwd>
		1484	inside, you would write:
		1485
		1486	aio_wd "/etc", sub {
		1487	my $etcdir = shift;
		1488
		1489	# although $etcdir can be undef on error, there is generally no reason
		1490	# to check for errors here, as aio_stat will fail with ENOENT
		1491	# when $etcdir is undef.
		1492
		1493	aio_stat [$etcdir, "passwd"], sub {
		1494	# yay
		1495	};
		1496	};
		1497
		1498	That C<aio_wd> is a request and not a normal function shows that creating
		1499	an IO::AIO::WD object is itself a potentially blocking operation, which is
		1500	why it is done asynchronously.
		1501
		1502	To stat the directory obtained with C<aio_wd> above, one could write
		1503	either of the following three request calls:
		1504
		1505	aio_lstat "/etc" , sub { ... # pathname as normal string
		1506	aio_lstat [$wd, "."], sub { ... # "." relative to $wd (i.e. $wd itself)
		1507	aio_lstat $wd , sub { ... # shorthand for the previous
		1508
		1509	As with normal pathnames, IO::AIO keeps a copy of the working directory
		1510	object and the pathname string, so you could write the following without
		1511	causing any issues due to C<$path> getting reused:
		1512
		1513	my $path = [$wd, undef];
		1514
		1515	for my $name (qw(abc def ghi)) {
		1516	$path->[1] = $name;
		1517	aio_stat $path, sub {
		1518	# ...
		1519	};
		1520	}
		1521
		1522	There are some caveats: when directories get renamed (or deleted), the
		1523	pathname string doesn't change, so will point to the new directory (or
		1524	nowhere at all), while the directory fd, if available on the system,
		1525	will still point to the original directory. Most functions accepting a
		1526	pathname will use the directory fd on newer systems, and the string on
		1527	older systems. Some functions (such as realpath) will always rely on the
		1528	string form of the pathname.
		1529
		1530	So this functionality is mainly useful to get some protection against
		1531	C<chdir>, to easily get an absolute path out of a relative path for future
		1532	reference, and to speed up doing many operations in the same directory
		1533	(e.g. when stat'ing all files in a directory).
		1534
		1535	The following functions implement this working directory abstraction:
		1536
		1537	=over 4
		1538
		1539	=item aio_wd $pathname, $callback->($wd)
		1540
		1541	Asynchonously canonicalise the given pathname and convert it to an
		1542	IO::AIO::WD object representing it. If possible and supported on the
		1543	system, also open a directory fd to speed up pathname resolution relative
		1544	to this working directory.
		1545
		1546	If something goes wrong, then C<undef> is passwd to the callback instead
		1547	of a working directory object and C<$!> is set appropriately. Since
		1548	passing C<undef> as working directory component of a pathname fails the
		1549	request with C<ENOENT>, there is often no need for error checking in the
		1550	C<aio_wd> callback, as future requests using the value will fail in the
		1551	expected way.
		1552
		1553	If this call isn't available because your OS lacks it or it couldn't be
		1554	detected, it will be emulated by calling C<fsync> instead.
		1555
		1556	=item IO::AIO::CWD
		1557
		1558	This is a compiletime constant (object) that represents the process
		1559	current working directory.
		1560
		1561	Specifying this object as working directory object for a pathname is as if
		1562	the pathname would be specified directly, without a directory object. For
		1563	example, these calls are functionally identical:
		1564
		1565	aio_stat "somefile", sub { ... };
		1566	aio_stat [IO::AIO::CWD, "somefile"], sub { ... };
		1567
		1568	=back
		1569
		1570	To recover the path associated with an IO::AIO::WD object, you can use
		1571	C<aio_realpath>:
		1572
		1573	aio_realpath $wd, sub {
		1574	warn "path is $_[0]\n";
		1575	};
		1576
1241		1577
1242	=head2 IO::AIO::REQ CLASS	1578	=head2 IO::AIO::REQ CLASS
1243		1579
1244	All non-aggregate C<aio_*> functions return an object of this class when	1580	All non-aggregate C<aio_*> functions return an object of this class when
1245	called in non-void context.	1581	called in non-void context.
…		…
1363		1699
1364	Sets a feeder/generator on this group: every group can have an attached	1700	Sets a feeder/generator on this group: every group can have an attached
1365	generator that generates requests if idle. The idea behind this is that,	1701	generator that generates requests if idle. The idea behind this is that,
1366	although you could just queue as many requests as you want in a group,	1702	although you could just queue as many requests as you want in a group,
1367	this might starve other requests for a potentially long time. For example,	1703	this might starve other requests for a potentially long time. For example,
1368	C<aio_scandir> might generate hundreds of thousands C<aio_stat> requests,	1704	C<aio_scandir> might generate hundreds of thousands of C<aio_stat>
1369	delaying any later requests for a long time.	1705	requests, delaying any later requests for a long time.
1370		1706
1371	To avoid this, and allow incremental generation of requests, you can	1707	To avoid this, and allow incremental generation of requests, you can
1372	instead a group and set a feeder on it that generates those requests. The	1708	instead a group and set a feeder on it that generates those requests. The
1373	feed callback will be called whenever there are few enough (see C<limit>,	1709	feed callback will be called whenever there are few enough (see C<limit>,
1374	below) requests active in the group itself and is expected to queue more	1710	below) requests active in the group itself and is expected to queue more
…		…
1423		1759
1424	See C<poll_cb> for an example.	1760	See C<poll_cb> for an example.
1425		1761
1426	=item IO::AIO::poll_cb	1762	=item IO::AIO::poll_cb
1427		1763
1428	Process some outstanding events on the result pipe. You have to call	1764	Process some requests that have reached the result phase (i.e. they have
		1765	been executed but the results are not yet reported). You have to call
		1766	this "regularly" to finish outstanding requests.
		1767
1429	this regularly. Returns C<0> if all events could be processed (or there	1768	Returns C<0> if all events could be processed (or there were no
1430	were no events to process), or C<-1> if it returned earlier for whatever	1769	events to process), or C<-1> if it returned earlier for whatever
1431	reason. Returns immediately when no events are outstanding. The amount of	1770	reason. Returns immediately when no events are outstanding. The amount
1432	events processed depends on the settings of C<IO::AIO::max_poll_req> and	1771	of events processed depends on the settings of C<IO::AIO::max_poll_req>,
1433	C<IO::AIO::max_poll_time>.	1772	C<IO::AIO::max_poll_time> and C<IO::AIO::max_outstanding>.
1434		1773
1435	If not all requests were processed for whatever reason, the filehandle	1774	If not all requests were processed for whatever reason, the poll file
1436	will still be ready when C<poll_cb> returns, so normally you don't have to	1775	descriptor will still be ready when C<poll_cb> returns, so normally you
1437	do anything special to have it called later.	1776	don't have to do anything special to have it called later.
1438		1777
1439	Apart from calling C<IO::AIO::poll_cb> when the event filehandle becomes	1778	Apart from calling C<IO::AIO::poll_cb> when the event filehandle becomes
1440	ready, it can be beneficial to call this function from loops which submit	1779	ready, it can be beneficial to call this function from loops which submit
1441	a lot of requests, to make sure the results get processed when they become	1780	a lot of requests, to make sure the results get processed when they become
1442	available and not just when the loop is finished and the event loop takes	1781	available and not just when the loop is finished and the event loop takes
…		…
1451	poll => 'r', async => 1,	1790	poll => 'r', async => 1,
1452	cb => \&IO::AIO::poll_cb);	1791	cb => \&IO::AIO::poll_cb);
1453		1792
1454	=item IO::AIO::poll_wait	1793	=item IO::AIO::poll_wait
1455		1794
1456	If there are any outstanding requests and none of them in the result	1795	Wait until either at least one request is in the result phase or no
1457	phase, wait till the result filehandle becomes ready for reading (simply	1796	requests are outstanding anymore.
1458	does a C<select> on the filehandle. This is useful if you want to	1797
1459	synchronously wait for some requests to finish).	1798	This is useful if you want to synchronously wait for some requests to
		1799	become ready, without actually handling them.
1460		1800
1461	See C<nreqs> for an example.	1801	See C<nreqs> for an example.
1462		1802
1463	=item IO::AIO::poll	1803	=item IO::AIO::poll
1464		1804
…		…
1653		1993
1654	=item IO::AIO::fadvise $fh, $offset, $len, $advice	1994	=item IO::AIO::fadvise $fh, $offset, $len, $advice
1655		1995
1656	Simply calls the C<posix_fadvise> function (see its	1996	Simply calls the C<posix_fadvise> function (see its
1657	manpage for details). The following advice constants are	1997	manpage for details). The following advice constants are
1658	avaiable: C<IO::AIO::FADV_NORMAL>, C<IO::AIO::FADV_SEQUENTIAL>,	1998	available: C<IO::AIO::FADV_NORMAL>, C<IO::AIO::FADV_SEQUENTIAL>,
1659	C<IO::AIO::FADV_RANDOM>, C<IO::AIO::FADV_NOREUSE>,	1999	C<IO::AIO::FADV_RANDOM>, C<IO::AIO::FADV_NOREUSE>,
1660	C<IO::AIO::FADV_WILLNEED>, C<IO::AIO::FADV_DONTNEED>.	2000	C<IO::AIO::FADV_WILLNEED>, C<IO::AIO::FADV_DONTNEED>.
1661		2001
1662	On systems that do not implement C<posix_fadvise>, this function returns	2002	On systems that do not implement C<posix_fadvise>, this function returns
1663	ENOSYS, otherwise the return value of C<posix_fadvise>.	2003	ENOSYS, otherwise the return value of C<posix_fadvise>.
1664		2004
1665	=item IO::AIO::madvise $scalar, $offset, $len, $advice	2005	=item IO::AIO::madvise $scalar, $offset, $len, $advice
1666		2006
1667	Simply calls the C<posix_madvise> function (see its	2007	Simply calls the C<posix_madvise> function (see its
1668	manpage for details). The following advice constants are	2008	manpage for details). The following advice constants are
1669	avaiable: C<IO::AIO::MADV_NORMAL>, C<IO::AIO::MADV_SEQUENTIAL>,	2009	available: C<IO::AIO::MADV_NORMAL>, C<IO::AIO::MADV_SEQUENTIAL>,
1670	C<IO::AIO::MADV_RANDOM>, C<IO::AIO::MADV_WILLNEED>, C<IO::AIO::MADV_DONTNEED>.	2010	C<IO::AIO::MADV_RANDOM>, C<IO::AIO::MADV_WILLNEED>, C<IO::AIO::MADV_DONTNEED>.
1671		2011
1672	On systems that do not implement C<posix_madvise>, this function returns	2012	On systems that do not implement C<posix_madvise>, this function returns
1673	ENOSYS, otherwise the return value of C<posix_madvise>.	2013	ENOSYS, otherwise the return value of C<posix_madvise>.
1674		2014
1675	=item IO::AIO::mprotect $scalar, $offset, $len, $protect	2015	=item IO::AIO::mprotect $scalar, $offset, $len, $protect
1676		2016
1677	Simply calls the C<mprotect> function on the preferably AIO::mmap'ed	2017	Simply calls the C<mprotect> function on the preferably AIO::mmap'ed
1678	$scalar (see its manpage for details). The following protect	2018	$scalar (see its manpage for details). The following protect
1679	constants are avaiable: C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_READ>,	2019	constants are available: C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_READ>,
1680	C<IO::AIO::PROT_WRITE>, C<IO::AIO::PROT_EXEC>.	2020	C<IO::AIO::PROT_WRITE>, C<IO::AIO::PROT_EXEC>.
1681		2021
1682	On systems that do not implement C<mprotect>, this function returns	2022	On systems that do not implement C<mprotect>, this function returns
1683	ENOSYS, otherwise the return value of C<mprotect>.	2023	ENOSYS, otherwise the return value of C<mprotect>.
1684		2024
1685	=item IO::AIO::mmap $scalar, $length, $prot, $flags, $fh[, $offset]	2025	=item IO::AIO::mmap $scalar, $length, $prot, $flags, $fh[, $offset]
1686		2026
1687	Memory-maps a file (or anonymous memory range) and attaches it to the	2027	Memory-maps a file (or anonymous memory range) and attaches it to the
1688	given C<$scalar>, which will act like a string scalar.	2028	given C<$scalar>, which will act like a string scalar. Returns true on
		2029	success, and false otherwise.
1689		2030
1690	The only operations allowed on the scalar are C<substr>/C<vec> that don't	2031	The only operations allowed on the scalar are C<substr>/C<vec> that don't
1691	change the string length, and most read-only operations such as copying it	2032	change the string length, and most read-only operations such as copying it
1692	or searching it with regexes and so on.	2033	or searching it with regexes and so on.
1693		2034
…		…
1746	Calls the C<munlockall> function.	2087	Calls the C<munlockall> function.
1747		2088
1748	On systems that do not implement C<munlockall>, this function returns	2089	On systems that do not implement C<munlockall>, this function returns
1749	ENOSYS, otherwise the return value of C<munlockall>.	2090	ENOSYS, otherwise the return value of C<munlockall>.
1750		2091
		2092	=item IO::AIO::splice $r_fh, $r_off, $w_fh, $w_off, $length, $flags
		2093
		2094	Calls the GNU/Linux C<splice(2)> syscall, if available. If C<$r_off> or
		2095	C<$w_off> are C<undef>, then C<NULL> is passed for these, otherwise they
		2096	should be the file offset.
		2097
		2098	C<$r_fh> and C<$w_fh> should not refer to the same file, as splice might
		2099	silently corrupt the data in this case.
		2100
		2101	The following symbol flag values are available: C<IO::AIO::SPLICE_F_MOVE>,
		2102	C<IO::AIO::SPLICE_F_NONBLOCK>, C<IO::AIO::SPLICE_F_MORE> and
		2103	C<IO::AIO::SPLICE_F_GIFT>.
		2104
		2105	See the C<splice(2)> manpage for details.
		2106
		2107	=item IO::AIO::tee $r_fh, $w_fh, $length, $flags
		2108
		2109	Calls the GNU/Linux C<tee(2)> syscall, see it's manpage and the
		2110	description for C<IO::AIO::splice> above for details.
		2111
1751	=back	2112	=back
1752		2113
1753	=cut	2114	=cut
1754		2115
1755	min_parallel 8;	2116	min_parallel 8;
…		…
1792	=head2 FORK BEHAVIOUR	2153	=head2 FORK BEHAVIOUR
1793		2154
1794	Usage of pthreads in a program changes the semantics of fork	2155	Usage of pthreads in a program changes the semantics of fork
1795	considerably. Specifically, only async-safe functions can be called after	2156	considerably. Specifically, only async-safe functions can be called after
1796	fork. Perl doesn't know about this, so in general, you cannot call fork	2157	fork. Perl doesn't know about this, so in general, you cannot call fork
1797	with defined behaviour in perl. IO::AIO uses pthreads, so this applies,	2158	with defined behaviour in perl if pthreads are involved. IO::AIO uses
1798	but many other extensions and (for inexplicable reasons) perl itself often	2159	pthreads, so this applies, but many other extensions and (for inexplicable
1799	is linked against pthreads, so this limitation applies.	2160	reasons) perl itself often is linked against pthreads, so this limitation
		2161	applies to quite a lot of perls.
1800		2162
1801	Some operating systems have extensions that allow safe use of fork, and	2163	This module no longer tries to fight your OS, or POSIX. That means IO::AIO
1802	this module should do "the right thing" on those, and tries on others. At	2164	only works in the process that loaded it. Forking is fully supported, but
1803	the time of this writing (2011) only GNU/Linux supports these extensions	2165	using IO::AIO in the child is not.
1804	to POSIX.	2166
		2167	You might get around by not I<using> IO::AIO before (or after)
		2168	forking. You could also try to call the L<IO::AIO::reinit> function in the
		2169	child:
		2170
		2171	=over 4
		2172
		2173	=item IO::AIO::reinit
		2174
		2175	Abandons all current requests and I/O threads and simply reinitialises all
		2176	data structures. This is not an operation supported by any standards, but
		2177	happens to work on GNU/Linux and some newer BSD systems.
		2178
		2179	The only reasonable use for this function is to call it after forking, if
		2180	C<IO::AIO> was used in the parent. Calling it while IO::AIO is active in
		2181	the process will result in undefined behaviour. Calling it at any time
		2182	will also result in any undefined (by POSIX) behaviour.
		2183
		2184	=back
1805		2185
1806	=head2 MEMORY USAGE	2186	=head2 MEMORY USAGE
1807		2187
1808	Per-request usage:	2188	Per-request usage:
1809		2189

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Comparing IO-AIO/AIO.pm (file contents): Revision 1.199 by root, Wed Jun 29 12:46:36 2011 UTC vs. Revision 1.240 by root, Mon Dec 17 06:18:39 2012 UTC

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Comparing IO-AIO/AIO.pm (file contents):
Revision 1.199 by root, Wed Jun 29 12:46:36 2011 UTC vs.
Revision 1.240 by root, Mon Dec 17 06:18:39 2012 UTC