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

Comparing IO-AIO/AIO.pm (file contents):
Revision 1.202 by root, Tue Jul 5 14:02:15 2011 UTC vs.
Revision 1.220 by root, Sun Apr 1 17:46:02 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 = '3.93';	173	our $VERSION = '4.13';
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_realpath 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_fallocate
		179	aio_pathsync aio_readahead
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
…		…
204		206
205	This section simply lists the prototypes of the most important functions	207	This section simply lists the prototypes of the most important functions
206	for quick reference. See the following sections for function-by-function	208	for 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)
222	aio_unlink $pathname, $callback->($status)	226	aio_unlink $pathname, $callback->($status)
223	aio_mknod $path, $mode, $dev, $callback->($status)	227	aio_mknod $pathname, $mode, $dev, $callback->($status)
224	aio_link $srcpath, $dstpath, $callback->($status)	228	aio_link $srcpath, $dstpath, $callback->($status)
225	aio_symlink $srcpath, $dstpath, $callback->($status)	229	aio_symlink $srcpath, $dstpath, $callback->($status)
226	aio_readlink $path, $callback->($link)	230	aio_readlink $pathname, $callback->($link)
227	aio_realpath $path, $callback->($link)	231	aio_realpath $pathname, $callback->($link)
228	aio_rename $srcpath, $dstpath, $callback->($status)	232	aio_rename $srcpath, $dstpath, $callback->($status)
229	aio_mkdir $pathname, $mode, $callback->($status)	233	aio_mkdir $pathname, $mode, $callback->($status)
230	aio_rmdir $pathname, $callback->($status)	234	aio_rmdir $pathname, $callback->($status)
231	aio_readdir $pathname, $callback->($entries)	235	aio_readdir $pathname, $callback->($entries)
232	aio_readdirx $pathname, $flags, $callback->($entries, $flags)	236	aio_readdirx $pathname, $flags, $callback->($entries, $flags)
233	IO::AIO::READDIR_DENTS IO::AIO::READDIR_DIRS_FIRST	237	IO::AIO::READDIR_DENTS IO::AIO::READDIR_DIRS_FIRST
234	IO::AIO::READDIR_STAT_ORDER IO::AIO::READDIR_FOUND_UNKNOWN	238	IO::AIO::READDIR_STAT_ORDER IO::AIO::READDIR_FOUND_UNKNOWN
		239	aio_scandir $pathname, $maxreq, $callback->($dirs, $nondirs)
235	aio_load $path, $data, $callback->($status)	240	aio_load $pathname, $data, $callback->($status)
236	aio_copy $srcpath, $dstpath, $callback->($status)	241	aio_copy $srcpath, $dstpath, $callback->($status)
237	aio_move $srcpath, $dstpath, $callback->($status)	242	aio_move $srcpath, $dstpath, $callback->($status)
238	aio_scandir $path, $maxreq, $callback->($dirs, $nondirs)
239	aio_rmtree $path, $callback->($status)	243	aio_rmtree $pathname, $callback->($status)
240	aio_sync $callback->($status)	244	aio_sync $callback->($status)
		245	aio_syncfs $fh, $callback->($status)
241	aio_fsync $fh, $callback->($status)	246	aio_fsync $fh, $callback->($status)
242	aio_fdatasync $fh, $callback->($status)	247	aio_fdatasync $fh, $callback->($status)
243	aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status)	248	aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status)
244	aio_pathsync $path, $callback->($status)	249	aio_pathsync $pathname, $callback->($status)
245	aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)	250	aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
246	aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)	251	aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
247	aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status)	252	aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status)
248	aio_mlockall $flags, $callback->($status)	253	aio_mlockall $flags, $callback->($status)
249	aio_group $callback->(...)	254	aio_group $callback->(...)
…		…
272	IO::AIO::madvise $scalar, $offset, $length, $advice	277	IO::AIO::madvise $scalar, $offset, $length, $advice
273	IO::AIO::mprotect $scalar, $offset, $length, $protect	278	IO::AIO::mprotect $scalar, $offset, $length, $protect
274	IO::AIO::munlock $scalar, $offset = 0, $length = undef	279	IO::AIO::munlock $scalar, $offset = 0, $length = undef
275	IO::AIO::munlockall	280	IO::AIO::munlockall
276		281
277	=head2 AIO REQUEST FUNCTIONS	282	=head2 API NOTES
278		283
279	All the C<aio_*> calls are more or less thin wrappers around the syscall	284	All the C<aio_*> calls are more or less thin wrappers around the syscall
280	with the same name (sans C<aio_>). The arguments are similar or identical,	285	with the same name (sans C<aio_>). The arguments are similar or identical,
281	and they all accept an additional (and optional) C<$callback> argument	286	and they all accept an additional (and optional) C<$callback> argument
282	which must be a code reference. This code reference will get called with	287	which must be a code reference. This code reference will be called after
283	the syscall return code (e.g. most syscalls return C<-1> on error, unlike	288	the syscall has been executed in an asynchronous fashion. The results
284	perl, which usually delivers "false") as its sole argument after the given	289	of the request will be passed as arguments to the callback (and, if an
285	syscall has been executed asynchronously.	290	error occured, in C<$!>) - for most requests the syscall return code (e.g.
		291	most syscalls return C<-1> on error, unlike perl, which usually delivers
		292	"false").
		293
		294	Some requests (such as C<aio_readdir>) pass the actual results and
		295	communicate failures by passing C<undef>.
286		296
287	All functions expecting a filehandle keep a copy of the filehandle	297	All functions expecting a filehandle keep a copy of the filehandle
288	internally until the request has finished.	298	internally until the request has finished.
289		299
290	All functions return request objects of type L<IO::AIO::REQ> that allow	300	All functions return request objects of type L<IO::AIO::REQ> that allow
291	further manipulation of those requests while they are in-flight.	301	further manipulation of those requests while they are in-flight.
292		302
293	The pathnames you pass to these routines I<must> be absolute and	303	The pathnames you pass to these routines I<should> be absolute. The
294	encoded as octets. The reason for the former is that at the time the	304	reason for this is that at the time the request is being executed, the
295	request is being executed, the current working directory could have	305	current working directory could have changed. Alternatively, you can
296	changed. Alternatively, you can make sure that you never change the	306	make sure that you never change the current working directory anywhere
297	current working directory anywhere in the program and then use relative	307	in the program and then use relative paths. You can also take advantage
298	paths.	308	of IO::AIOs working directory abstraction, that lets you specify paths
		309	relative to some previously-opened "working directory object" - see the
		310	description of the C<IO::AIO::WD> class later in this document.
299		311
300	To encode pathnames as octets, either make sure you either: a) always pass	312	To encode pathnames as octets, either make sure you either: a) always pass
301	in filenames you got from outside (command line, readdir etc.) without	313	in filenames you got from outside (command line, readdir etc.) without
302	tinkering, b) are ASCII or ISO 8859-1, c) use the Encode module and encode	314	tinkering, b) are in your native filesystem encoding, c) use the Encode
303	your pathnames to the locale (or other) encoding in effect in the user	315	module and encode your pathnames to the locale (or other) encoding in
304	environment, d) use Glib::filename_from_unicode on unicode filenames or e)	316	effect in the user environment, d) use Glib::filename_from_unicode on
305	use something else to ensure your scalar has the correct contents.	317	unicode filenames or e) use something else to ensure your scalar has the
		318	correct contents.
306		319
307	This works, btw. independent of the internal UTF-8 bit, which IO::AIO	320	This works, btw. independent of the internal UTF-8 bit, which IO::AIO
308	handles correctly whether it is set or not.	321	handles correctly whether it is set or not.
		322
		323	=head2 AIO REQUEST FUNCTIONS
309		324
310	=over 4	325	=over 4
311		326
312	=item $prev_pri = aioreq_pri [$pri]	327	=item $prev_pri = aioreq_pri [$pri]
313		328
…		…
395		410
396	Or in other words: the file descriptor will be closed, but it will not be	411	Or in other words: the file descriptor will be closed, but it will not be
397	free for reuse until the perl filehandle is closed.	412	free for reuse until the perl filehandle is closed.
398		413
399	=cut	414	=cut
		415
		416	=item aio_seek $fh, $offset, $whence, $callback->($offs)
		417
		418	Seeks the filehandle to the new C<$offset>, similarly to perl'S
		419	C<sysseek>. The C<$whence> can use the traditional values (C<0> for
		420	C<IO::AIO::SEEK_SET>, C<1> for C<IO::AIO::SEEK_CUR> or C<2> for
		421	C<IO::AIO::SEEK_END>).
		422
		423	The resulting absolute offset will be passed to the callback, or C<-1> in
		424	case of an error.
		425
		426	In theory, the C<$whence> constants could be different than the
		427	corresponding values from L<Fcntl>, but perl guarantees they are the same,
		428	so don't panic.
400		429
401	=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)	430	=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
402		431
403	=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)	432	=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
404		433
…		…
612		641
613	Asynchronously unlink (delete) a file and call the callback with the	642	Asynchronously unlink (delete) a file and call the callback with the
614	result code.	643	result code.
615		644
616		645
617	=item aio_mknod $path, $mode, $dev, $callback->($status)	646	=item aio_mknod $pathname, $mode, $dev, $callback->($status)
618		647
619	[EXPERIMENTAL]	648	[EXPERIMENTAL]
620		649
621	Asynchronously create a device node (or fifo). See mknod(2).	650	Asynchronously create a device node (or fifo). See mknod(2).
622		651
623	The only (POSIX-) portable way of calling this function is:	652	The only (POSIX-) portable way of calling this function is:
624		653
625	aio_mknod $path, IO::AIO::S_IFIFO \| $mode, 0, sub { ...	654	aio_mknod $pathname, IO::AIO::S_IFIFO \| $mode, 0, sub { ...
626		655
627	See C<aio_stat> for info about some potentially helpful extra constants	656	See C<aio_stat> for info about some potentially helpful extra constants
628	and functions.	657	and functions.
629		658
630	=item aio_link $srcpath, $dstpath, $callback->($status)	659	=item aio_link $srcpath, $dstpath, $callback->($status)
…		…
637		666
638	Asynchronously create a new symbolic link to the existing object at C<$srcpath> at	667	Asynchronously create a new symbolic link to the existing object at C<$srcpath> at
639	the path C<$dstpath> and call the callback with the result code.	668	the path C<$dstpath> and call the callback with the result code.
640		669
641		670
642	=item aio_readlink $path, $callback->($link)	671	=item aio_readlink $pathname, $callback->($link)
643		672
644	Asynchronously read the symlink specified by C<$path> and pass it to	673	Asynchronously read the symlink specified by C<$path> and pass it to
645	the callback. If an error occurs, nothing or undef gets passed to the	674	the callback. If an error occurs, nothing or undef gets passed to the
646	callback.	675	callback.
647		676
648		677
649	=item aio_realpath $path, $callback->($path)	678	=item aio_realpath $pathname, $callback->($path)
650		679
651	Asynchronously make the path absolute and resolve any symlinks in	680	Asynchronously make the path absolute and resolve any symlinks in
652	C<$path>. The resulting path only consists of directories (Same as	681	C<$path>. The resulting path only consists of directories (Same as
653	L<Cwd::realpath>).	682	L<Cwd::realpath>).
654		683
…		…
685	array-ref with the filenames.	714	array-ref with the filenames.
686		715
687		716
688	=item aio_readdirx $pathname, $flags, $callback->($entries, $flags)	717	=item aio_readdirx $pathname, $flags, $callback->($entries, $flags)
689		718
690	Quite similar to C<aio_readdir>, but the C<$flags> argument allows to tune	719	Quite similar to C<aio_readdir>, but the C<$flags> argument allows one to
691	behaviour and output format. In case of an error, C<$entries> will be	720	tune behaviour and output format. In case of an error, C<$entries> will be
692	C<undef>.	721	C<undef>.
693		722
694	The flags are a combination of the following constants, ORed together (the	723	The flags are a combination of the following constants, ORed together (the
695	flags will also be passed to the callback, possibly modified):	724	flags will also be passed to the callback, possibly modified):
696		725
…		…
743		772
744	=item IO::AIO::READDIR_FOUND_UNKNOWN	773	=item IO::AIO::READDIR_FOUND_UNKNOWN
745		774
746	This flag should not be set when calling C<aio_readdirx>. Instead, it	775	This flag should not be set when calling C<aio_readdirx>. Instead, it
747	is being set by C<aio_readdirx>, when any of the C<$type>'s found were	776	is being set by C<aio_readdirx>, when any of the C<$type>'s found were
748	C<IO::AIO::DT_UNKNOWN>. The absense of this flag therefore indicates that all	777	C<IO::AIO::DT_UNKNOWN>. The absence of this flag therefore indicates that all
749	C<$type>'s are known, which can be used to speed up some algorithms.	778	C<$type>'s are known, which can be used to speed up some algorithms.
750		779
751	=back	780	=back
752		781
753		782
754	=item aio_load $path, $data, $callback->($status)	783	=item aio_load $pathname, $data, $callback->($status)
755		784
756	This is a composite request that tries to fully load the given file into	785	This is a composite request that tries to fully load the given file into
757	memory. Status is the same as with aio_read.	786	memory. Status is the same as with aio_read.
758		787
759	=cut	788	=cut
…		…
894	};	923	};
895		924
896	$grp	925	$grp
897	}	926	}
898		927
899	=item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs)	928	=item aio_scandir $pathname, $maxreq, $callback->($dirs, $nondirs)
900		929
901	Scans a directory (similar to C<aio_readdir>) but additionally tries to	930	Scans a directory (similar to C<aio_readdir>) but additionally tries to
902	efficiently separate the entries of directory C<$path> into two sets of	931	efficiently separate the entries of directory C<$path> into two sets of
903	names, directories you can recurse into (directories), and ones you cannot	932	names, directories you can recurse into (directories), and ones you cannot
904	recurse into (everything else, including symlinks to directories).	933	recurse into (everything else, including symlinks to directories).
…		…
935	Then entries will be sorted into likely directories a non-initial dot	964	Then entries will be sorted into likely directories a non-initial dot
936	currently) and likely non-directories (see C<aio_readdirx>). Then every	965	currently) and likely non-directories (see C<aio_readdirx>). Then every
937	entry plus an appended C</.> will be C<stat>'ed, likely directories first,	966	entry plus an appended C</.> will be C<stat>'ed, likely directories first,
938	in order of their inode numbers. If that succeeds, it assumes that the	967	in order of their inode numbers. If that succeeds, it assumes that the
939	entry is a directory or a symlink to directory (which will be checked	968	entry is a directory or a symlink to directory (which will be checked
940	seperately). This is often faster than stat'ing the entry itself because	969	separately). This is often faster than stat'ing the entry itself because
941	filesystems might detect the type of the entry without reading the inode	970	filesystems might detect the type of the entry without reading the inode
942	data (e.g. ext2fs filetype feature), even on systems that cannot return	971	data (e.g. ext2fs filetype feature), even on systems that cannot return
943	the filetype information on readdir.	972	the filetype information on readdir.
944		973
945	If the known number of directories (link count - 2) has been reached, the	974	If the known number of directories (link count - 2) has been reached, the
…		…
961		990
962	my $grp = aio_group $cb;	991	my $grp = aio_group $cb;
963		992
964	$maxreq = 4 if $maxreq <= 0;	993	$maxreq = 4 if $maxreq <= 0;
965		994
966	# stat once	995	# get a wd object
967	aioreq_pri $pri;	996	aioreq_pri $pri;
968	add $grp aio_stat $path, sub {	997	add $grp aio_wd $path, sub {
		998	$_[0]
969	return $grp->result () if $_[0];	999	or return $grp->result ();
970	my $now = time;
971	my $hash1 = join ":", (stat _)[0,1,3,7,9];
972		1000
973	# read the directory entries	1001	my $wd = [shift, "."];
		1002
		1003	# stat once
974	aioreq_pri $pri;	1004	aioreq_pri $pri;
975	add $grp aio_readdirx $path, READDIR_DIRS_FIRST, sub {	1005	add $grp aio_stat $wd, sub {
976	my $entries = shift
977	or return $grp->result ();	1006	return $grp->result () if $_[0];
		1007	my $now = time;
		1008	my $hash1 = join ":", (stat _)[0,1,3,7,9];
978		1009
979	# stat the dir another time	1010	# read the directory entries
980	aioreq_pri $pri;	1011	aioreq_pri $pri;
		1012	add $grp aio_readdirx $wd, READDIR_DIRS_FIRST, sub {
		1013	my $entries = shift
		1014	or return $grp->result ();
		1015
		1016	# stat the dir another time
		1017	aioreq_pri $pri;
981	add $grp aio_stat $path, sub {	1018	add $grp aio_stat $wd, sub {
982	my $hash2 = join ":", (stat _)[0,1,3,7,9];	1019	my $hash2 = join ":", (stat _)[0,1,3,7,9];
983		1020
984	my $ndirs;	1021	my $ndirs;
985		1022
986	# take the slow route if anything looks fishy	1023	# take the slow route if anything looks fishy
987	if ($hash1 ne $hash2 or (stat _)[9] == $now) {	1024	if ($hash1 ne $hash2 or (stat _)[9] == $now) {
988	$ndirs = -1;	1025	$ndirs = -1;
989	} else {	1026	} else {
990	# if nlink == 2, we are finished	1027	# if nlink == 2, we are finished
991	# for non-posix-fs's, we rely on nlink < 2	1028	# for non-posix-fs's, we rely on nlink < 2
992	$ndirs = (stat _)[3] - 2	1029	$ndirs = (stat _)[3] - 2
993	or return $grp->result ([], $entries);	1030	or return $grp->result ([], $entries);
994	}	1031	}
995		1032
996	my (@dirs, @nondirs);	1033	my (@dirs, @nondirs);
997		1034
998	my $statgrp = add $grp aio_group sub {	1035	my $statgrp = add $grp aio_group sub {
999	$grp->result (\@dirs, \@nondirs);	1036	$grp->result (\@dirs, \@nondirs);
1000	};	1037	};
1001		1038
1002	limit $statgrp $maxreq;	1039	limit $statgrp $maxreq;
1003	feed $statgrp sub {	1040	feed $statgrp sub {
1004	return unless @$entries;	1041	return unless @$entries;
1005	my $entry = shift @$entries;	1042	my $entry = shift @$entries;
1006		1043
1007	aioreq_pri $pri;	1044	aioreq_pri $pri;
		1045	$wd->[1] = "$entry/.";
1008	add $statgrp aio_stat "$path/$entry/.", sub {	1046	add $statgrp aio_stat $wd, sub {
1009	if ($_[0] < 0) {	1047	if ($_[0] < 0) {
1010	push @nondirs, $entry;	1048	push @nondirs, $entry;
1011	} else {	1049	} else {
1012	# need to check for real directory	1050	# need to check for real directory
1013	aioreq_pri $pri;	1051	aioreq_pri $pri;
		1052	$wd->[1] = $entry;
1014	add $statgrp aio_lstat "$path/$entry", sub {	1053	add $statgrp aio_lstat $wd, sub {
1015	if (-d _) {	1054	if (-d _) {
1016	push @dirs, $entry;	1055	push @dirs, $entry;
1017		1056
1018	unless (--$ndirs) {	1057	unless (--$ndirs) {
1019	push @nondirs, @$entries;	1058	push @nondirs, @$entries;
1020	feed $statgrp;	1059	feed $statgrp;
		1060	}
		1061	} else {
		1062	push @nondirs, $entry;
1021	}	1063	}
1022	} else {
1023	push @nondirs, $entry;
1024	}	1064	}
1025	}	1065	}
1026	}	1066	};
1027	};	1067	};
1028	};	1068	};
1029	};	1069	};
1030	};	1070	};
1031	};	1071	};
1032		1072
1033	$grp	1073	$grp
1034	}	1074	}
1035		1075
1036	=item aio_rmtree $path, $callback->($status)	1076	=item aio_rmtree $pathname, $callback->($status)
1037		1077
1038	Delete a directory tree starting (and including) C<$path>, return the	1078	Delete a directory tree starting (and including) C<$path>, return the
1039	status of the final C<rmdir> only. This is a composite request that	1079	status of the final C<rmdir> only. This is a composite request that
1040	uses C<aio_scandir> to recurse into and rmdir directories, and unlink	1080	uses C<aio_scandir> to recurse into and rmdir directories, and unlink
1041	everything else.	1081	everything else.
…		…
1083	callback with the fdatasync result code.	1123	callback with the fdatasync result code.
1084		1124
1085	If this call isn't available because your OS lacks it or it couldn't be	1125	If this call isn't available because your OS lacks it or it couldn't be
1086	detected, it will be emulated by calling C<fsync> instead.	1126	detected, it will be emulated by calling C<fsync> instead.
1087		1127
		1128	=item aio_syncfs $fh, $callback->($status)
		1129
		1130	Asynchronously call the syncfs syscall to sync the filesystem associated
		1131	to the given filehandle and call the callback with the syncfs result
		1132	code. If syncfs is not available, calls sync(), but returns C<-1> and sets
		1133	errno to C<ENOSYS> nevertheless.
		1134
1088	=item aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status)	1135	=item aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status)
1089		1136
1090	Sync the data portion of the file specified by C<$offset> and C<$length>	1137	Sync the data portion of the file specified by C<$offset> and C<$length>
1091	to disk (but NOT the metadata), by calling the Linux-specific	1138	to disk (but NOT the metadata), by calling the Linux-specific
1092	sync_file_range call. If sync_file_range is not available or it returns	1139	sync_file_range call. If sync_file_range is not available or it returns
…		…
1095	C<$flags> can be a combination of C<IO::AIO::SYNC_FILE_RANGE_WAIT_BEFORE>,	1142	C<$flags> can be a combination of C<IO::AIO::SYNC_FILE_RANGE_WAIT_BEFORE>,
1096	C<IO::AIO::SYNC_FILE_RANGE_WRITE> and	1143	C<IO::AIO::SYNC_FILE_RANGE_WRITE> and
1097	C<IO::AIO::SYNC_FILE_RANGE_WAIT_AFTER>: refer to the sync_file_range	1144	C<IO::AIO::SYNC_FILE_RANGE_WAIT_AFTER>: refer to the sync_file_range
1098	manpage for details.	1145	manpage for details.
1099		1146
1100	=item aio_pathsync $path, $callback->($status)	1147	=item aio_pathsync $pathname, $callback->($status)
1101		1148
1102	This request tries to open, fsync and close the given path. This is a	1149	This request tries to open, fsync and close the given path. This is a
1103	composite request intended to sync directories after directory operations	1150	composite request intended to sync directories after directory operations
1104	(E.g. rename). This might not work on all operating systems or have any	1151	(E.g. rename). This might not work on all operating systems or have any
1105	specific effect, but usually it makes sure that directory changes get	1152	specific effect, but usually it makes sure that directory changes get
…		…
1248	immense (it blocks a thread for a long time) so do not use this function	1295	immense (it blocks a thread for a long time) so do not use this function
1249	except to put your application under artificial I/O pressure.	1296	except to put your application under artificial I/O pressure.
1250		1297
1251	=back	1298	=back
1252		1299
		1300
		1301	=head2 IO::AIO::WD - multiple working directories
		1302
		1303	Your process only has one current working directory, which is used by all
		1304	threads. This makes it hard to use relative paths (some other component
		1305	could call C<chdir> at any time, and it is hard to control when the path
		1306	will be used by IO::AIO).
		1307
		1308	One solution for this is to always use absolute paths. This usually works,
		1309	but can be quite slow (the kernel has to walk the whole path on every
		1310	access), and can also be a hassle to implement.
		1311
		1312	Newer POSIX systems have a number of functions (openat, fdopendir,
		1313	futimensat and so on) that make it possible to specify working directories
		1314	per operation.
		1315
		1316	For portability, and because the clowns who "designed", or shall I write,
		1317	perpetrated this new interface were obviously half-drunk, this abstraction
		1318	cannot be perfect, though.
		1319
		1320	IO::AIO allows you to convert directory paths into a so-called IO::AIO::WD
		1321	object. This object stores the canonicalised, absolute version of the
		1322	path, and on systems that allow it, also a directory file descriptor.
		1323
		1324	Everywhere where a pathname is accepted by IO::AIO (e.g. in C<aio_stat>
		1325	or C<aio_unlink>), one can specify an array reference with an IO::AIO::WD
		1326	object and a pathname instead (or the IO::AIO::WD object alone, which
		1327	gets interpreted as C<[$wd, "."]>). If the pathname is absolute, the
		1328	IO::AIO::WD object is ignored, otherwise the pathname is resolved relative
		1329	to that IO::AIO::WD object.
		1330
		1331	For example, to get a wd object for F</etc> and then stat F<passwd>
		1332	inside, you would write:
		1333
		1334	aio_wd "/etc", sub {
		1335	my $etcdir = shift;
		1336
		1337	# although $etcdir can be undef on error, there is generally no reason
		1338	# to check for errors here, as aio_stat will fail with ENOENT
		1339	# when $etcdir is undef.
		1340
		1341	aio_stat [$etcdir, "passwd"], sub {
		1342	# yay
		1343	};
		1344	};
		1345
		1346	That C<aio_wd> is a request and not a normal function shows that creating
		1347	an IO::AIO::WD object is itself a potentially blocking operation, which is
		1348	why it is done asynchronously.
		1349
		1350	To stat the directory obtained with C<aio_wd> above, one could write
		1351	either of the following three request calls:
		1352
		1353	aio_lstat "/etc" , sub { ... # pathname as normal string
		1354	aio_lstat [$wd, "."], sub { ... # "." relative to $wd (i.e. $wd itself)
		1355	aio_lstat $wd , sub { ... # shorthand for the previous
		1356
		1357	As with normal pathnames, IO::AIO keeps a copy of the working directory
		1358	object and the pathname string, so you could write the following without
		1359	causing any issues due to C<$path> getting reused:
		1360
		1361	my $path = [$wd, undef];
		1362
		1363	for my $name (qw(abc def ghi)) {
		1364	$path->[1] = $name;
		1365	aio_stat $path, sub {
		1366	# ...
		1367	};
		1368	}
		1369
		1370	There are some caveats: when directories get renamed (or deleted), the
		1371	pathname string doesn't change, so will point to the new directory (or
		1372	nowhere at all), while the directory fd, if available on the system,
		1373	will still point to the original directory. Most functions accepting a
		1374	pathname will use the directory fd on newer systems, and the string on
		1375	older systems. Some functions (such as realpath) will always rely on the
		1376	string form of the pathname.
		1377
		1378	So this fucntionality is mainly useful to get some protection against
		1379	C<chdir>, to easily get an absolute path out of a relative path for future
		1380	reference, and to speed up doing many operations in the same directory
		1381	(e.g. when stat'ing all files in a directory).
		1382
		1383	The following functions implement this working directory abstraction:
		1384
		1385	=over 4
		1386
		1387	=item aio_wd $pathname, $callback->($wd)
		1388
		1389	Asynchonously canonicalise the given pathname and convert it to an
		1390	IO::AIO::WD object representing it. If possible and supported on the
		1391	system, also open a directory fd to speed up pathname resolution relative
		1392	to this working directory.
		1393
		1394	If something goes wrong, then C<undef> is passwd to the callback instead
		1395	of a working directory object and C<$!> is set appropriately. Since
		1396	passing C<undef> as working directory component of a pathname fails the
		1397	request with C<ENOENT>, there is often no need for error checking in the
		1398	C<aio_wd> callback, as future requests using the value will fail in the
		1399	expected way.
		1400
		1401	If this call isn't available because your OS lacks it or it couldn't be
		1402	detected, it will be emulated by calling C<fsync> instead.
		1403
		1404	=item IO::AIO::CWD
		1405
		1406	This is a compiletime constant (object) that represents the process
		1407	current working directory.
		1408
		1409	Specifying this object as working directory object for a pathname is as
		1410	if the pathname would be specified directly, without a directory object,
		1411	e.g., these calls are functionally identical:
		1412
		1413	aio_stat "somefile", sub { ... };
		1414	aio_stat [IO::AIO::CWD, "somefile"], sub { ... };
		1415
		1416	=back
		1417
		1418
1253	=head2 IO::AIO::REQ CLASS	1419	=head2 IO::AIO::REQ CLASS
1254		1420
1255	All non-aggregate C<aio_*> functions return an object of this class when	1421	All non-aggregate C<aio_*> functions return an object of this class when
1256	called in non-void context.	1422	called in non-void context.
1257		1423
…		…
1374		1540
1375	Sets a feeder/generator on this group: every group can have an attached	1541	Sets a feeder/generator on this group: every group can have an attached
1376	generator that generates requests if idle. The idea behind this is that,	1542	generator that generates requests if idle. The idea behind this is that,
1377	although you could just queue as many requests as you want in a group,	1543	although you could just queue as many requests as you want in a group,
1378	this might starve other requests for a potentially long time. For example,	1544	this might starve other requests for a potentially long time. For example,
1379	C<aio_scandir> might generate hundreds of thousands C<aio_stat> requests,	1545	C<aio_scandir> might generate hundreds of thousands of C<aio_stat>
1380	delaying any later requests for a long time.	1546	requests, delaying any later requests for a long time.
1381		1547
1382	To avoid this, and allow incremental generation of requests, you can	1548	To avoid this, and allow incremental generation of requests, you can
1383	instead a group and set a feeder on it that generates those requests. The	1549	instead a group and set a feeder on it that generates those requests. The
1384	feed callback will be called whenever there are few enough (see C<limit>,	1550	feed callback will be called whenever there are few enough (see C<limit>,
1385	below) requests active in the group itself and is expected to queue more	1551	below) requests active in the group itself and is expected to queue more
…		…
1664		1830
1665	=item IO::AIO::fadvise $fh, $offset, $len, $advice	1831	=item IO::AIO::fadvise $fh, $offset, $len, $advice
1666		1832
1667	Simply calls the C<posix_fadvise> function (see its	1833	Simply calls the C<posix_fadvise> function (see its
1668	manpage for details). The following advice constants are	1834	manpage for details). The following advice constants are
1669	avaiable: C<IO::AIO::FADV_NORMAL>, C<IO::AIO::FADV_SEQUENTIAL>,	1835	available: C<IO::AIO::FADV_NORMAL>, C<IO::AIO::FADV_SEQUENTIAL>,
1670	C<IO::AIO::FADV_RANDOM>, C<IO::AIO::FADV_NOREUSE>,	1836	C<IO::AIO::FADV_RANDOM>, C<IO::AIO::FADV_NOREUSE>,
1671	C<IO::AIO::FADV_WILLNEED>, C<IO::AIO::FADV_DONTNEED>.	1837	C<IO::AIO::FADV_WILLNEED>, C<IO::AIO::FADV_DONTNEED>.
1672		1838
1673	On systems that do not implement C<posix_fadvise>, this function returns	1839	On systems that do not implement C<posix_fadvise>, this function returns
1674	ENOSYS, otherwise the return value of C<posix_fadvise>.	1840	ENOSYS, otherwise the return value of C<posix_fadvise>.
1675		1841
1676	=item IO::AIO::madvise $scalar, $offset, $len, $advice	1842	=item IO::AIO::madvise $scalar, $offset, $len, $advice
1677		1843
1678	Simply calls the C<posix_madvise> function (see its	1844	Simply calls the C<posix_madvise> function (see its
1679	manpage for details). The following advice constants are	1845	manpage for details). The following advice constants are
1680	avaiable: C<IO::AIO::MADV_NORMAL>, C<IO::AIO::MADV_SEQUENTIAL>,	1846	available: C<IO::AIO::MADV_NORMAL>, C<IO::AIO::MADV_SEQUENTIAL>,
1681	C<IO::AIO::MADV_RANDOM>, C<IO::AIO::MADV_WILLNEED>, C<IO::AIO::MADV_DONTNEED>.	1847	C<IO::AIO::MADV_RANDOM>, C<IO::AIO::MADV_WILLNEED>, C<IO::AIO::MADV_DONTNEED>.
1682		1848
1683	On systems that do not implement C<posix_madvise>, this function returns	1849	On systems that do not implement C<posix_madvise>, this function returns
1684	ENOSYS, otherwise the return value of C<posix_madvise>.	1850	ENOSYS, otherwise the return value of C<posix_madvise>.
1685		1851
1686	=item IO::AIO::mprotect $scalar, $offset, $len, $protect	1852	=item IO::AIO::mprotect $scalar, $offset, $len, $protect
1687		1853
1688	Simply calls the C<mprotect> function on the preferably AIO::mmap'ed	1854	Simply calls the C<mprotect> function on the preferably AIO::mmap'ed
1689	$scalar (see its manpage for details). The following protect	1855	$scalar (see its manpage for details). The following protect
1690	constants are avaiable: C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_READ>,	1856	constants are available: C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_READ>,
1691	C<IO::AIO::PROT_WRITE>, C<IO::AIO::PROT_EXEC>.	1857	C<IO::AIO::PROT_WRITE>, C<IO::AIO::PROT_EXEC>.
1692		1858
1693	On systems that do not implement C<mprotect>, this function returns	1859	On systems that do not implement C<mprotect>, this function returns
1694	ENOSYS, otherwise the return value of C<mprotect>.	1860	ENOSYS, otherwise the return value of C<mprotect>.
1695		1861
…		…
1803	=head2 FORK BEHAVIOUR	1969	=head2 FORK BEHAVIOUR
1804		1970
1805	Usage of pthreads in a program changes the semantics of fork	1971	Usage of pthreads in a program changes the semantics of fork
1806	considerably. Specifically, only async-safe functions can be called after	1972	considerably. Specifically, only async-safe functions can be called after
1807	fork. Perl doesn't know about this, so in general, you cannot call fork	1973	fork. Perl doesn't know about this, so in general, you cannot call fork
1808	with defined behaviour in perl. IO::AIO uses pthreads, so this applies,	1974	with defined behaviour in perl if pthreads are involved. IO::AIO uses
1809	but many other extensions and (for inexplicable reasons) perl itself often	1975	pthreads, so this applies, but many other extensions and (for inexplicable
1810	is linked against pthreads, so this limitation applies.	1976	reasons) perl itself often is linked against pthreads, so this limitation
		1977	applies to quite a lot of perls.
1811		1978
1812	Some operating systems have extensions that allow safe use of fork, and	1979	This module no longer tries to fight your OS, or POSIX. That means IO::AIO
1813	this module should do "the right thing" on those, and tries on others. At	1980	only works in the process that loaded it. Forking is fully supported, but
1814	the time of this writing (2011) only GNU/Linux supports these extensions	1981	using IO::AIO in the child is not.
1815	to POSIX.	1982
		1983	You might get around by not I<using> IO::AIO before (or after)
		1984	forking. You could also try to call the L<IO::AIO::reinit> function in the
		1985	child:
		1986
		1987	=over 4
		1988
		1989	=item IO::AIO::reinit
		1990
		1991	Abandons all current requests and I/O threads and simply reinitialises all
		1992	data structures. This is not an operation supported by any standards, but
		1993	happens to work on GNU/Linux and some newer BSD systems.
		1994
		1995	The only reasonable use for this function is to call it after forking, if
		1996	C<IO::AIO> was used in the parent. Calling it while IO::AIO is active in
		1997	the process will result in undefined behaviour. Calling it at any time
		1998	will also result in any undefined (by POSIX) behaviour.
		1999
		2000	=back
1816		2001
1817	=head2 MEMORY USAGE	2002	=head2 MEMORY USAGE
1818		2003
1819	Per-request usage:	2004	Per-request usage:
1820		2005

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Comparing IO-AIO/AIO.pm (file contents): Revision 1.202 by root, Tue Jul 5 14:02:15 2011 UTC vs. Revision 1.220 by root, Sun Apr 1 17:46:02 2012 UTC

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Comparing IO-AIO/AIO.pm (file contents):
Revision 1.202 by root, Tue Jul 5 14:02:15 2011 UTC vs.
Revision 1.220 by root, Sun Apr 1 17:46:02 2012 UTC