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

Comparing IO-AIO/AIO.pm (file contents):
Revision 1.203 by root, Thu Jul 7 22:36:18 2011 UTC vs.
Revision 1.224 by root, Sat Apr 7 00:50:33 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 = '4.14';
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_fallocate	178	aio_fsync aio_syncfs aio_fdatasync aio_sync_file_range aio_fallocate
179	aio_pathsync aio_readahead	179	aio_pathsync aio_readahead aio_fiemap
180	aio_rename aio_link aio_move aio_copy aio_group	180	aio_rename aio_link aio_move aio_copy aio_group
181	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
182	aio_chmod aio_utime aio_truncate	182	aio_chmod aio_utime aio_truncate
183	aio_msync aio_mtouch aio_mlock aio_mlockall	183	aio_msync aio_mtouch aio_mlock aio_mlockall
184	aio_statvfs);	184	aio_statvfs
		185	aio_wd);
185		186
186	our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice));	187	our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice));
187	our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush	188	our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush
188	min_parallel max_parallel max_idle idle_timeout	189	min_parallel max_parallel max_idle idle_timeout
189	nreqs nready npending nthreads	190	nreqs nready npending nthreads
…		…
205		206
206	This section simply lists the prototypes of the most important functions	207	This section simply lists the prototypes of the most important functions
207	for quick reference. See the following sections for function-by-function	208	for quick reference. See the following sections for function-by-function
208	documentation.	209	documentation.
209		210
		211	aio_wd $pathname, $callback->($wd)
210	aio_open $pathname, $flags, $mode, $callback->($fh)	212	aio_open $pathname, $flags, $mode, $callback->($fh)
211	aio_close $fh, $callback->($status)	213	aio_close $fh, $callback->($status)
		214	aio_seek $fh,$offset,$whence, $callback->($offs)
212	aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)	215	aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
213	aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)	216	aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
214	aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval)	217	aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval)
215	aio_readahead $fh,$offset,$length, $callback->($retval)	218	aio_readahead $fh,$offset,$length, $callback->($retval)
216	aio_stat $fh_or_path, $callback->($status)	219	aio_stat $fh_or_path, $callback->($status)
217	aio_lstat $fh, $callback->($status)	220	aio_lstat $fh, $callback->($status)
218	aio_statvfs $fh_or_path, $callback->($statvfs)	221	aio_statvfs $fh_or_path, $callback->($statvfs)
219	aio_utime $fh_or_path, $atime, $mtime, $callback->($status)	222	aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
220	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)
221	aio_truncate $fh_or_path, $offset, $callback->($status)	225	aio_truncate $fh_or_path, $offset, $callback->($status)
222	aio_chmod $fh_or_path, $mode, $callback->($status)
223	aio_unlink $pathname, $callback->($status)	226	aio_unlink $pathname, $callback->($status)
224	aio_mknod $path, $mode, $dev, $callback->($status)	227	aio_mknod $pathname, $mode, $dev, $callback->($status)
225	aio_link $srcpath, $dstpath, $callback->($status)	228	aio_link $srcpath, $dstpath, $callback->($status)
226	aio_symlink $srcpath, $dstpath, $callback->($status)	229	aio_symlink $srcpath, $dstpath, $callback->($status)
227	aio_readlink $path, $callback->($link)	230	aio_readlink $pathname, $callback->($link)
228	aio_realpath $path, $callback->($link)	231	aio_realpath $pathname, $callback->($link)
229	aio_rename $srcpath, $dstpath, $callback->($status)	232	aio_rename $srcpath, $dstpath, $callback->($status)
230	aio_mkdir $pathname, $mode, $callback->($status)	233	aio_mkdir $pathname, $mode, $callback->($status)
231	aio_rmdir $pathname, $callback->($status)	234	aio_rmdir $pathname, $callback->($status)
232	aio_readdir $pathname, $callback->($entries)	235	aio_readdir $pathname, $callback->($entries)
233	aio_readdirx $pathname, $flags, $callback->($entries, $flags)	236	aio_readdirx $pathname, $flags, $callback->($entries, $flags)
234	IO::AIO::READDIR_DENTS IO::AIO::READDIR_DIRS_FIRST	237	IO::AIO::READDIR_DENTS IO::AIO::READDIR_DIRS_FIRST
235	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)
236	aio_load $path, $data, $callback->($status)	240	aio_load $pathname, $data, $callback->($status)
237	aio_copy $srcpath, $dstpath, $callback->($status)	241	aio_copy $srcpath, $dstpath, $callback->($status)
238	aio_move $srcpath, $dstpath, $callback->($status)	242	aio_move $srcpath, $dstpath, $callback->($status)
239	aio_scandir $path, $maxreq, $callback->($dirs, $nondirs)
240	aio_rmtree $path, $callback->($status)	243	aio_rmtree $pathname, $callback->($status)
241	aio_sync $callback->($status)	244	aio_sync $callback->($status)
		245	aio_syncfs $fh, $callback->($status)
242	aio_fsync $fh, $callback->($status)	246	aio_fsync $fh, $callback->($status)
243	aio_fdatasync $fh, $callback->($status)	247	aio_fdatasync $fh, $callback->($status)
244	aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status)	248	aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status)
245	aio_pathsync $path, $callback->($status)	249	aio_pathsync $pathname, $callback->($status)
246	aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)	250	aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
247	aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)	251	aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
248	aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status)	252	aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status)
249	aio_mlockall $flags, $callback->($status)	253	aio_mlockall $flags, $callback->($status)
250	aio_group $callback->(...)	254	aio_group $callback->(...)
…		…
273	IO::AIO::madvise $scalar, $offset, $length, $advice	277	IO::AIO::madvise $scalar, $offset, $length, $advice
274	IO::AIO::mprotect $scalar, $offset, $length, $protect	278	IO::AIO::mprotect $scalar, $offset, $length, $protect
275	IO::AIO::munlock $scalar, $offset = 0, $length = undef	279	IO::AIO::munlock $scalar, $offset = 0, $length = undef
276	IO::AIO::munlockall	280	IO::AIO::munlockall
277		281
278	=head2 AIO REQUEST FUNCTIONS	282	=head2 API NOTES
279		283
280	All the C<aio_*> calls are more or less thin wrappers around the syscall	284	All the C<aio_*> calls are more or less thin wrappers around the syscall
281	with the same name (sans C<aio_>). The arguments are similar or identical,	285	with the same name (sans C<aio_>). The arguments are similar or identical,
282	and they all accept an additional (and optional) C<$callback> argument	286	and they all accept an additional (and optional) C<$callback> argument
283	which must be a code reference. This code reference will get called with	287	which must be a code reference. This code reference will be called after
284	the syscall return code (e.g. most syscalls return C<-1> on error, unlike	288	the syscall has been executed in an asynchronous fashion. The results
285	perl, which usually delivers "false") as its sole argument after the given	289	of the request will be passed as arguments to the callback (and, if an
286	syscall has been executed asynchronously.	290	error occured, in C<$!>) - 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>.
287		296
288	All functions expecting a filehandle keep a copy of the filehandle	297	All functions expecting a filehandle keep a copy of the filehandle
289	internally until the request has finished.	298	internally until the request has finished.
290		299
291	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
292	further manipulation of those requests while they are in-flight.	301	further manipulation of those requests while they are in-flight.
293		302
294	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
295	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
296	request is being executed, the current working directory could have	305	current working directory could have changed. Alternatively, you can
297	changed. Alternatively, you can make sure that you never change the	306	make sure that you never change the current working directory anywhere
298	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
299	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.
300		311
301	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
302	in filenames you got from outside (command line, readdir etc.) without	313	in filenames you got from outside (command line, readdir etc.) without
303	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
304	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
305	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
306	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.
307		319
308	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
309	handles correctly whether it is set or not.	321	handles correctly whether it is set or not.
		322
		323	=head2 AIO REQUEST FUNCTIONS
310		324
311	=over 4	325	=over 4
312		326
313	=item $prev_pri = aioreq_pri [$pri]	327	=item $prev_pri = aioreq_pri [$pri]
314		328
…		…
396		410
397	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
398	free for reuse until the perl filehandle is closed.	412	free for reuse until the perl filehandle is closed.
399		413
400	=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.
401		429
402	=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)	430	=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
403		431
404	=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)	432	=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
405		433
…		…
613		641
614	Asynchronously unlink (delete) a file and call the callback with the	642	Asynchronously unlink (delete) a file and call the callback with the
615	result code.	643	result code.
616		644
617		645
618	=item aio_mknod $path, $mode, $dev, $callback->($status)	646	=item aio_mknod $pathname, $mode, $dev, $callback->($status)
619		647
620	[EXPERIMENTAL]	648	[EXPERIMENTAL]
621		649
622	Asynchronously create a device node (or fifo). See mknod(2).	650	Asynchronously create a device node (or fifo). See mknod(2).
623		651
624	The only (POSIX-) portable way of calling this function is:	652	The only (POSIX-) portable way of calling this function is:
625		653
626	aio_mknod $path, IO::AIO::S_IFIFO \| $mode, 0, sub { ...	654	aio_mknod $pathname, IO::AIO::S_IFIFO \| $mode, 0, sub { ...
627		655
628	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
629	and functions.	657	and functions.
630		658
631	=item aio_link $srcpath, $dstpath, $callback->($status)	659	=item aio_link $srcpath, $dstpath, $callback->($status)
…		…
638		666
639	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
640	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.
641		669
642		670
643	=item aio_readlink $path, $callback->($link)	671	=item aio_readlink $pathname, $callback->($link)
644		672
645	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
646	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
647	callback.	675	callback.
648		676
649		677
650	=item aio_realpath $path, $callback->($path)	678	=item aio_realpath $pathname, $callback->($path)
651		679
652	Asynchronously make the path absolute and resolve any symlinks in	680	Asynchronously make the path absolute and resolve any symlinks in
653	C<$path>. The resulting path only consists of directories (Same as	681	C<$path>. The resulting path only consists of directories (Same as
654	L<Cwd::realpath>).	682	L<Cwd::realpath>).
655		683
…		…
686	array-ref with the filenames.	714	array-ref with the filenames.
687		715
688		716
689	=item aio_readdirx $pathname, $flags, $callback->($entries, $flags)	717	=item aio_readdirx $pathname, $flags, $callback->($entries, $flags)
690		718
691	Quite similar to C<aio_readdir>, but the C<$flags> argument allows to tune	719	Quite similar to C<aio_readdir>, but the C<$flags> argument allows one to
692	behaviour and output format. In case of an error, C<$entries> will be	720	tune behaviour and output format. In case of an error, C<$entries> will be
693	C<undef>.	721	C<undef>.
694		722
695	The flags are a combination of the following constants, ORed together (the	723	The flags are a combination of the following constants, ORed together (the
696	flags will also be passed to the callback, possibly modified):	724	flags will also be passed to the callback, possibly modified):
697		725
…		…
744		772
745	=item IO::AIO::READDIR_FOUND_UNKNOWN	773	=item IO::AIO::READDIR_FOUND_UNKNOWN
746		774
747	This flag should not be set when calling C<aio_readdirx>. Instead, it	775	This flag should not be set when calling C<aio_readdirx>. Instead, it
748	is being set by C<aio_readdirx>, when any of the C<$type>'s found were	776	is being set by C<aio_readdirx>, when any of the C<$type>'s found were
749	C<IO::AIO::DT_UNKNOWN>. The absense of this flag therefore indicates that all	777	C<IO::AIO::DT_UNKNOWN>. The absence of this flag therefore indicates that all
750	C<$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.
751		779
752	=back	780	=back
753		781
754		782
755	=item aio_load $path, $data, $callback->($status)	783	=item aio_load $pathname, $data, $callback->($status)
756		784
757	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
758	memory. Status is the same as with aio_read.	786	memory. Status is the same as with aio_read.
759		787
760	=cut	788	=cut
…		…
895	};	923	};
896		924
897	$grp	925	$grp
898	}	926	}
899		927
900	=item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs)	928	=item aio_scandir $pathname, $maxreq, $callback->($dirs, $nondirs)
901		929
902	Scans a directory (similar to C<aio_readdir>) but additionally tries to	930	Scans a directory (similar to C<aio_readdir>) but additionally tries to
903	efficiently separate the entries of directory C<$path> into two sets of	931	efficiently separate the entries of directory C<$path> into two sets of
904	names, directories you can recurse into (directories), and ones you cannot	932	names, directories you can recurse into (directories), and ones you cannot
905	recurse into (everything else, including symlinks to directories).	933	recurse into (everything else, including symlinks to directories).
…		…
936	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
937	currently) and likely non-directories (see C<aio_readdirx>). Then every	965	currently) and likely non-directories (see C<aio_readdirx>). Then every
938	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,
939	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
940	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
941	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
942	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
943	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
944	the filetype information on readdir.	972	the filetype information on readdir.
945		973
946	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
…		…
962		990
963	my $grp = aio_group $cb;	991	my $grp = aio_group $cb;
964		992
965	$maxreq = 4 if $maxreq <= 0;	993	$maxreq = 4 if $maxreq <= 0;
966		994
967	# stat once	995	# get a wd object
968	aioreq_pri $pri;	996	aioreq_pri $pri;
969	add $grp aio_stat $path, sub {	997	add $grp aio_wd $path, sub {
		998	$_[0]
970	return $grp->result () if $_[0];	999	or return $grp->result ();
971	my $now = time;
972	my $hash1 = join ":", (stat _)[0,1,3,7,9];
973		1000
974	# read the directory entries	1001	my $wd = [shift, "."];
		1002
		1003	# stat once
975	aioreq_pri $pri;	1004	aioreq_pri $pri;
976	add $grp aio_readdirx $path, READDIR_DIRS_FIRST, sub {	1005	add $grp aio_stat $wd, sub {
977	my $entries = shift
978	or return $grp->result ();	1006	return $grp->result () if $_[0];
		1007	my $now = time;
		1008	my $hash1 = join ":", (stat _)[0,1,3,7,9];
979		1009
980	# stat the dir another time	1010	# read the directory entries
981	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;
982	add $grp aio_stat $path, sub {	1018	add $grp aio_stat $wd, sub {
983	my $hash2 = join ":", (stat _)[0,1,3,7,9];	1019	my $hash2 = join ":", (stat _)[0,1,3,7,9];
984		1020
985	my $ndirs;	1021	my $ndirs;
986		1022
987	# take the slow route if anything looks fishy	1023	# take the slow route if anything looks fishy
988	if ($hash1 ne $hash2 or (stat _)[9] == $now) {	1024	if ($hash1 ne $hash2 or (stat _)[9] == $now) {
989	$ndirs = -1;	1025	$ndirs = -1;
990	} else {	1026	} else {
991	# if nlink == 2, we are finished	1027	# if nlink == 2, we are finished
992	# for non-posix-fs's, we rely on nlink < 2	1028	# for non-posix-fs's, we rely on nlink < 2
993	$ndirs = (stat _)[3] - 2	1029	$ndirs = (stat _)[3] - 2
994	or return $grp->result ([], $entries);	1030	or return $grp->result ([], $entries);
995	}	1031	}
996		1032
997	my (@dirs, @nondirs);	1033	my (@dirs, @nondirs);
998		1034
999	my $statgrp = add $grp aio_group sub {	1035	my $statgrp = add $grp aio_group sub {
1000	$grp->result (\@dirs, \@nondirs);	1036	$grp->result (\@dirs, \@nondirs);
1001	};	1037	};
1002		1038
1003	limit $statgrp $maxreq;	1039	limit $statgrp $maxreq;
1004	feed $statgrp sub {	1040	feed $statgrp sub {
1005	return unless @$entries;	1041	return unless @$entries;
1006	my $entry = shift @$entries;	1042	my $entry = shift @$entries;
1007		1043
1008	aioreq_pri $pri;	1044	aioreq_pri $pri;
		1045	$wd->[1] = "$entry/.";
1009	add $statgrp aio_stat "$path/$entry/.", sub {	1046	add $statgrp aio_stat $wd, sub {
1010	if ($_[0] < 0) {	1047	if ($_[0] < 0) {
1011	push @nondirs, $entry;	1048	push @nondirs, $entry;
1012	} else {	1049	} else {
1013	# need to check for real directory	1050	# need to check for real directory
1014	aioreq_pri $pri;	1051	aioreq_pri $pri;
		1052	$wd->[1] = $entry;
1015	add $statgrp aio_lstat "$path/$entry", sub {	1053	add $statgrp aio_lstat $wd, sub {
1016	if (-d _) {	1054	if (-d _) {
1017	push @dirs, $entry;	1055	push @dirs, $entry;
1018		1056
1019	unless (--$ndirs) {	1057	unless (--$ndirs) {
1020	push @nondirs, @$entries;	1058	push @nondirs, @$entries;
1021	feed $statgrp;	1059	feed $statgrp;
		1060	}
		1061	} else {
		1062	push @nondirs, $entry;
1022	}	1063	}
1023	} else {
1024	push @nondirs, $entry;
1025	}	1064	}
1026	}	1065	}
1027	}	1066	};
1028	};	1067	};
1029	};	1068	};
1030	};	1069	};
1031	};	1070	};
1032	};	1071	};
1033		1072
1034	$grp	1073	$grp
1035	}	1074	}
1036		1075
1037	=item aio_rmtree $path, $callback->($status)	1076	=item aio_rmtree $pathname, $callback->($status)
1038		1077
1039	Delete a directory tree starting (and including) C<$path>, return the	1078	Delete a directory tree starting (and including) C<$path>, return the
1040	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
1041	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
1042	everything else.	1081	everything else.
…		…
1084	callback with the fdatasync result code.	1123	callback with the fdatasync result code.
1085		1124
1086	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
1087	detected, it will be emulated by calling C<fsync> instead.	1126	detected, it will be emulated by calling C<fsync> instead.
1088		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
1089	=item aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status)	1135	=item aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status)
1090		1136
1091	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>
1092	to disk (but NOT the metadata), by calling the Linux-specific	1138	to disk (but NOT the metadata), by calling the Linux-specific
1093	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
…		…
1096	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>,
1097	C<IO::AIO::SYNC_FILE_RANGE_WRITE> and	1143	C<IO::AIO::SYNC_FILE_RANGE_WRITE> and
1098	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
1099	manpage for details.	1145	manpage for details.
1100		1146
1101	=item aio_pathsync $path, $callback->($status)	1147	=item aio_pathsync $pathname, $callback->($status)
1102		1148
1103	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
1104	composite request intended to sync directories after directory operations	1150	composite request intended to sync directories after directory operations
1105	(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
1106	specific effect, but usually it makes sure that directory changes get	1152	specific effect, but usually it makes sure that directory changes get
…		…
1203		1249
1204	Example: asynchronously lock all current and future pages into memory.	1250	Example: asynchronously lock all current and future pages into memory.
1205		1251
1206	aio_mlockall IO::AIO::MCL_FUTURE;	1252	aio_mlockall IO::AIO::MCL_FUTURE;
1207		1253
		1254	=item aio_fiemap $fh, $start, $length, $flags, $count, $cb->(\@extents)
		1255
		1256	Queries the extents of the given file (by calling the Linux FIEMAP ioctl,
		1257	see L<http://cvs.schmorp.de/IO-AIO/doc/fiemap.txt> for details). If the
		1258	C<ioctl> is not available on your OS, then this rquiest will fail with
		1259	C<ENOSYS>.
		1260
		1261	C<$start> is the starting offset to query extents for, C<$length> is the
		1262	size of the range to query - if it is C<undef>, then the whole file will
		1263	be queried.
		1264
		1265	C<$flags> is a combination of flags (C<IO::AIO::FIEMAP_FLAG_SYNC> or
		1266	C<IO::AIO::FIEMAP_FLAG_XATTR> - C<IO::AIO::FIEMAP_FLAGS_COMPAT> is also
		1267	exported), and is normally C<0> or C<IO::AIO::FIEMAP_FLAG_SYNC> to query
		1268	the data portion.
		1269
		1270	C<$count> is the maximum number of extent records to return. If it is
		1271	C<undef>, then IO::AIO queries all extents of the file. As a very special
		1272	case, if it is C<0>, then the callback receives the number of extents
		1273	instead of the extents themselves.
		1274
		1275	If an error occurs, the callback receives no arguments. The special
		1276	C<errno> value C<IO::AIO::EBADR> is available to test for flag errors.
		1277
		1278	Otherwise, the callback receives an array reference with extent
		1279	structures. Each extent structure is an array reference itself, with the
		1280	following members:
		1281
		1282	[$logical, $physical, $length, $flags]
		1283
		1284	Flags is any combination of the following flag values (typically either C<0>
		1285	or C<IO::AIO::FIEMAP_EXTENT_LAST>):
		1286
		1287	C<IO::AIO::FIEMAP_EXTENT_LAST>, C<IO::AIO::FIEMAP_EXTENT_UNKNOWN>,
		1288	C<IO::AIO::FIEMAP_EXTENT_DELALLOC>, C<IO::AIO::FIEMAP_EXTENT_ENCODED>,
		1289	C<IO::AIO::FIEMAP_EXTENT_DATA_ENCRYPTED>, C<IO::AIO::FIEMAP_EXTENT_NOT_ALIGNED>,
		1290	C<IO::AIO::FIEMAP_EXTENT_DATA_INLINE>, C<IO::AIO::FIEMAP_EXTENT_DATA_TAIL>,
		1291	C<IO::AIO::FIEMAP_EXTENT_UNWRITTEN>, C<IO::AIO::FIEMAP_EXTENT_MERGED> or
		1292	C<IO::AIO::FIEMAP_EXTENT_SHARED>.
		1293
1208	=item aio_group $callback->(...)	1294	=item aio_group $callback->(...)
1209		1295
1210	This is a very special aio request: Instead of doing something, it is a	1296	This is a very special aio request: Instead of doing something, it is a
1211	container for other aio requests, which is useful if you want to bundle	1297	container for other aio requests, which is useful if you want to bundle
1212	many requests into a single, composite, request with a definite callback	1298	many requests into a single, composite, request with a definite callback
…		…
1248	like sleep and file handle readable/writable, the overhead this creates is	1334	like sleep and file handle readable/writable, the overhead this creates is
1249	immense (it blocks a thread for a long time) so do not use this function	1335	immense (it blocks a thread for a long time) so do not use this function
1250	except to put your application under artificial I/O pressure.	1336	except to put your application under artificial I/O pressure.
1251		1337
1252	=back	1338	=back
		1339
		1340
		1341	=head2 IO::AIO::WD - multiple working directories
		1342
		1343	Your process only has one current working directory, which is used by all
		1344	threads. This makes it hard to use relative paths (some other component
		1345	could call C<chdir> at any time, and it is hard to control when the path
		1346	will be used by IO::AIO).
		1347
		1348	One solution for this is to always use absolute paths. This usually works,
		1349	but can be quite slow (the kernel has to walk the whole path on every
		1350	access), and can also be a hassle to implement.
		1351
		1352	Newer POSIX systems have a number of functions (openat, fdopendir,
		1353	futimensat and so on) that make it possible to specify working directories
		1354	per operation.
		1355
		1356	For portability, and because the clowns who "designed", or shall I write,
		1357	perpetrated this new interface were obviously half-drunk, this abstraction
		1358	cannot be perfect, though.
		1359
		1360	IO::AIO allows you to convert directory paths into a so-called IO::AIO::WD
		1361	object. This object stores the canonicalised, absolute version of the
		1362	path, and on systems that allow it, also a directory file descriptor.
		1363
		1364	Everywhere where a pathname is accepted by IO::AIO (e.g. in C<aio_stat>
		1365	or C<aio_unlink>), one can specify an array reference with an IO::AIO::WD
		1366	object and a pathname instead (or the IO::AIO::WD object alone, which
		1367	gets interpreted as C<[$wd, "."]>). If the pathname is absolute, the
		1368	IO::AIO::WD object is ignored, otherwise the pathname is resolved relative
		1369	to that IO::AIO::WD object.
		1370
		1371	For example, to get a wd object for F</etc> and then stat F<passwd>
		1372	inside, you would write:
		1373
		1374	aio_wd "/etc", sub {
		1375	my $etcdir = shift;
		1376
		1377	# although $etcdir can be undef on error, there is generally no reason
		1378	# to check for errors here, as aio_stat will fail with ENOENT
		1379	# when $etcdir is undef.
		1380
		1381	aio_stat [$etcdir, "passwd"], sub {
		1382	# yay
		1383	};
		1384	};
		1385
		1386	That C<aio_wd> is a request and not a normal function shows that creating
		1387	an IO::AIO::WD object is itself a potentially blocking operation, which is
		1388	why it is done asynchronously.
		1389
		1390	To stat the directory obtained with C<aio_wd> above, one could write
		1391	either of the following three request calls:
		1392
		1393	aio_lstat "/etc" , sub { ... # pathname as normal string
		1394	aio_lstat [$wd, "."], sub { ... # "." relative to $wd (i.e. $wd itself)
		1395	aio_lstat $wd , sub { ... # shorthand for the previous
		1396
		1397	As with normal pathnames, IO::AIO keeps a copy of the working directory
		1398	object and the pathname string, so you could write the following without
		1399	causing any issues due to C<$path> getting reused:
		1400
		1401	my $path = [$wd, undef];
		1402
		1403	for my $name (qw(abc def ghi)) {
		1404	$path->[1] = $name;
		1405	aio_stat $path, sub {
		1406	# ...
		1407	};
		1408	}
		1409
		1410	There are some caveats: when directories get renamed (or deleted), the
		1411	pathname string doesn't change, so will point to the new directory (or
		1412	nowhere at all), while the directory fd, if available on the system,
		1413	will still point to the original directory. Most functions accepting a
		1414	pathname will use the directory fd on newer systems, and the string on
		1415	older systems. Some functions (such as realpath) will always rely on the
		1416	string form of the pathname.
		1417
		1418	So this fucntionality is mainly useful to get some protection against
		1419	C<chdir>, to easily get an absolute path out of a relative path for future
		1420	reference, and to speed up doing many operations in the same directory
		1421	(e.g. when stat'ing all files in a directory).
		1422
		1423	The following functions implement this working directory abstraction:
		1424
		1425	=over 4
		1426
		1427	=item aio_wd $pathname, $callback->($wd)
		1428
		1429	Asynchonously canonicalise the given pathname and convert it to an
		1430	IO::AIO::WD object representing it. If possible and supported on the
		1431	system, also open a directory fd to speed up pathname resolution relative
		1432	to this working directory.
		1433
		1434	If something goes wrong, then C<undef> is passwd to the callback instead
		1435	of a working directory object and C<$!> is set appropriately. Since
		1436	passing C<undef> as working directory component of a pathname fails the
		1437	request with C<ENOENT>, there is often no need for error checking in the
		1438	C<aio_wd> callback, as future requests using the value will fail in the
		1439	expected way.
		1440
		1441	If this call isn't available because your OS lacks it or it couldn't be
		1442	detected, it will be emulated by calling C<fsync> instead.
		1443
		1444	=item IO::AIO::CWD
		1445
		1446	This is a compiletime constant (object) that represents the process
		1447	current working directory.
		1448
		1449	Specifying this object as working directory object for a pathname is as
		1450	if the pathname would be specified directly, without a directory object,
		1451	e.g., these calls are functionally identical:
		1452
		1453	aio_stat "somefile", sub { ... };
		1454	aio_stat [IO::AIO::CWD, "somefile"], sub { ... };
		1455
		1456	=back
		1457
1253		1458
1254	=head2 IO::AIO::REQ CLASS	1459	=head2 IO::AIO::REQ CLASS
1255		1460
1256	All non-aggregate C<aio_*> functions return an object of this class when	1461	All non-aggregate C<aio_*> functions return an object of this class when
1257	called in non-void context.	1462	called in non-void context.
…		…
1375		1580
1376	Sets a feeder/generator on this group: every group can have an attached	1581	Sets a feeder/generator on this group: every group can have an attached
1377	generator that generates requests if idle. The idea behind this is that,	1582	generator that generates requests if idle. The idea behind this is that,
1378	although you could just queue as many requests as you want in a group,	1583	although you could just queue as many requests as you want in a group,
1379	this might starve other requests for a potentially long time. For example,	1584	this might starve other requests for a potentially long time. For example,
1380	C<aio_scandir> might generate hundreds of thousands C<aio_stat> requests,	1585	C<aio_scandir> might generate hundreds of thousands of C<aio_stat>
1381	delaying any later requests for a long time.	1586	requests, delaying any later requests for a long time.
1382		1587
1383	To avoid this, and allow incremental generation of requests, you can	1588	To avoid this, and allow incremental generation of requests, you can
1384	instead a group and set a feeder on it that generates those requests. The	1589	instead a group and set a feeder on it that generates those requests. The
1385	feed callback will be called whenever there are few enough (see C<limit>,	1590	feed callback will be called whenever there are few enough (see C<limit>,
1386	below) requests active in the group itself and is expected to queue more	1591	below) requests active in the group itself and is expected to queue more
…		…
1665		1870
1666	=item IO::AIO::fadvise $fh, $offset, $len, $advice	1871	=item IO::AIO::fadvise $fh, $offset, $len, $advice
1667		1872
1668	Simply calls the C<posix_fadvise> function (see its	1873	Simply calls the C<posix_fadvise> function (see its
1669	manpage for details). The following advice constants are	1874	manpage for details). The following advice constants are
1670	avaiable: C<IO::AIO::FADV_NORMAL>, C<IO::AIO::FADV_SEQUENTIAL>,	1875	available: C<IO::AIO::FADV_NORMAL>, C<IO::AIO::FADV_SEQUENTIAL>,
1671	C<IO::AIO::FADV_RANDOM>, C<IO::AIO::FADV_NOREUSE>,	1876	C<IO::AIO::FADV_RANDOM>, C<IO::AIO::FADV_NOREUSE>,
1672	C<IO::AIO::FADV_WILLNEED>, C<IO::AIO::FADV_DONTNEED>.	1877	C<IO::AIO::FADV_WILLNEED>, C<IO::AIO::FADV_DONTNEED>.
1673		1878
1674	On systems that do not implement C<posix_fadvise>, this function returns	1879	On systems that do not implement C<posix_fadvise>, this function returns
1675	ENOSYS, otherwise the return value of C<posix_fadvise>.	1880	ENOSYS, otherwise the return value of C<posix_fadvise>.
1676		1881
1677	=item IO::AIO::madvise $scalar, $offset, $len, $advice	1882	=item IO::AIO::madvise $scalar, $offset, $len, $advice
1678		1883
1679	Simply calls the C<posix_madvise> function (see its	1884	Simply calls the C<posix_madvise> function (see its
1680	manpage for details). The following advice constants are	1885	manpage for details). The following advice constants are
1681	avaiable: C<IO::AIO::MADV_NORMAL>, C<IO::AIO::MADV_SEQUENTIAL>,	1886	available: C<IO::AIO::MADV_NORMAL>, C<IO::AIO::MADV_SEQUENTIAL>,
1682	C<IO::AIO::MADV_RANDOM>, C<IO::AIO::MADV_WILLNEED>, C<IO::AIO::MADV_DONTNEED>.	1887	C<IO::AIO::MADV_RANDOM>, C<IO::AIO::MADV_WILLNEED>, C<IO::AIO::MADV_DONTNEED>.
1683		1888
1684	On systems that do not implement C<posix_madvise>, this function returns	1889	On systems that do not implement C<posix_madvise>, this function returns
1685	ENOSYS, otherwise the return value of C<posix_madvise>.	1890	ENOSYS, otherwise the return value of C<posix_madvise>.
1686		1891
1687	=item IO::AIO::mprotect $scalar, $offset, $len, $protect	1892	=item IO::AIO::mprotect $scalar, $offset, $len, $protect
1688		1893
1689	Simply calls the C<mprotect> function on the preferably AIO::mmap'ed	1894	Simply calls the C<mprotect> function on the preferably AIO::mmap'ed
1690	$scalar (see its manpage for details). The following protect	1895	$scalar (see its manpage for details). The following protect
1691	constants are avaiable: C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_READ>,	1896	constants are available: C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_READ>,
1692	C<IO::AIO::PROT_WRITE>, C<IO::AIO::PROT_EXEC>.	1897	C<IO::AIO::PROT_WRITE>, C<IO::AIO::PROT_EXEC>.
1693		1898
1694	On systems that do not implement C<mprotect>, this function returns	1899	On systems that do not implement C<mprotect>, this function returns
1695	ENOSYS, otherwise the return value of C<mprotect>.	1900	ENOSYS, otherwise the return value of C<mprotect>.
1696		1901
…		…
1804	=head2 FORK BEHAVIOUR	2009	=head2 FORK BEHAVIOUR
1805		2010
1806	Usage of pthreads in a program changes the semantics of fork	2011	Usage of pthreads in a program changes the semantics of fork
1807	considerably. Specifically, only async-safe functions can be called after	2012	considerably. Specifically, only async-safe functions can be called after
1808	fork. Perl doesn't know about this, so in general, you cannot call fork	2013	fork. Perl doesn't know about this, so in general, you cannot call fork
1809	with defined behaviour in perl. IO::AIO uses pthreads, so this applies,	2014	with defined behaviour in perl if pthreads are involved. IO::AIO uses
1810	but many other extensions and (for inexplicable reasons) perl itself often	2015	pthreads, so this applies, but many other extensions and (for inexplicable
1811	is linked against pthreads, so this limitation applies.	2016	reasons) perl itself often is linked against pthreads, so this limitation
		2017	applies to quite a lot of perls.
1812		2018
1813	Some operating systems have extensions that allow safe use of fork, and	2019	This module no longer tries to fight your OS, or POSIX. That means IO::AIO
1814	this module should do "the right thing" on those, and tries on others. At	2020	only works in the process that loaded it. Forking is fully supported, but
1815	the time of this writing (2011) only GNU/Linux supports these extensions	2021	using IO::AIO in the child is not.
1816	to POSIX.	2022
		2023	You might get around by not I<using> IO::AIO before (or after)
		2024	forking. You could also try to call the L<IO::AIO::reinit> function in the
		2025	child:
		2026
		2027	=over 4
		2028
		2029	=item IO::AIO::reinit
		2030
		2031	Abandons all current requests and I/O threads and simply reinitialises all
		2032	data structures. This is not an operation supported by any standards, but
		2033	happens to work on GNU/Linux and some newer BSD systems.
		2034
		2035	The only reasonable use for this function is to call it after forking, if
		2036	C<IO::AIO> was used in the parent. Calling it while IO::AIO is active in
		2037	the process will result in undefined behaviour. Calling it at any time
		2038	will also result in any undefined (by POSIX) behaviour.
		2039
		2040	=back
1817		2041
1818	=head2 MEMORY USAGE	2042	=head2 MEMORY USAGE
1819		2043
1820	Per-request usage:	2044	Per-request usage:
1821		2045

Diff Legend

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

Comparing IO-AIO/AIO.pm (file contents): Revision 1.203 by root, Thu Jul 7 22:36:18 2011 UTC vs. Revision 1.224 by root, Sat Apr 7 00:50:33 2012 UTC

Diff Legend

Comparing IO-AIO/AIO.pm (file contents):
Revision 1.203 by root, Thu Jul 7 22:36:18 2011 UTC vs.
Revision 1.224 by root, Sat Apr 7 00:50:33 2012 UTC