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

Comparing IO-AIO/AIO.pm (file contents):
Revision 1.217 by root, Sun Oct 9 22:25:00 2011 UTC vs.
Revision 1.261 by root, Sat May 21 04:43:31 2016 UTC

…		…
68	=head2 EXAMPLE	68	=head2 EXAMPLE
69		69
70	This is a simple example that uses the EV module and loads	70	This is a simple example that uses the EV module and loads
71	F</etc/passwd> asynchronously:	71	F</etc/passwd> asynchronously:
72		72
73	use Fcntl;
74	use EV;	73	use EV;
75	use IO::AIO;	74	use IO::AIO;
76		75
77	# register the IO::AIO callback with EV	76	# register the IO::AIO callback with EV
78	my $aio_w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb;	77	my $aio_w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb;
…		…
95		94
96	# file contents now in $contents	95	# file contents now in $contents
97	print $contents;	96	print $contents;
98		97
99	# exit event loop and program	98	# exit event loop and program
100	EV::unloop;	99	EV::break;
101	};	100	};
102	};	101	};
103		102
104	# possibly queue up other requests, or open GUI windows,	103	# possibly queue up other requests, or open GUI windows,
105	# check for sockets etc. etc.	104	# check for sockets etc. etc.
106		105
107	# process events as long as there are some:	106	# process events as long as there are some:
108	EV::loop;	107	EV::run;
109		108
110	=head1 REQUEST ANATOMY AND LIFETIME	109	=head1 REQUEST ANATOMY AND LIFETIME
111		110
112	Every C<aio_*> function creates a request. which is a C data structure not	111	Every C<aio_*> function creates a request. which is a C data structure not
113	directly visible to Perl.	112	directly visible to Perl.
…		…
168	use common::sense;	167	use common::sense;
169		168
170	use base 'Exporter';	169	use base 'Exporter';
171		170
172	BEGIN {	171	BEGIN {
173	our $VERSION = '4.11';	172	our $VERSION = 4.34;
174		173
175	our @AIO_REQ = qw(aio_sendfile aio_read aio_write aio_open aio_close	174	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	175	aio_stat aio_lstat aio_unlink aio_rmdir aio_readdir aio_readdirx
177	aio_scandir aio_symlink aio_readlink aio_realpath aio_sync	176	aio_scandir aio_symlink aio_readlink aio_realpath aio_fcntl aio_ioctl
178	aio_fsync aio_syncfs aio_fdatasync aio_sync_file_range aio_fallocate	177	aio_sync aio_fsync aio_syncfs aio_fdatasync aio_sync_file_range
179	aio_pathsync aio_readahead	178	aio_pathsync aio_readahead aio_fiemap aio_allocate
180	aio_rename aio_link aio_move aio_copy aio_group	179	aio_rename aio_link aio_move aio_copy aio_group
181	aio_nop aio_mknod aio_load aio_rmtree aio_mkdir aio_chown	180	aio_nop aio_mknod aio_load aio_rmtree aio_mkdir aio_chown
182	aio_chmod aio_utime aio_truncate	181	aio_chmod aio_utime aio_truncate
183	aio_msync aio_mtouch aio_mlock aio_mlockall	182	aio_msync aio_mtouch aio_mlock aio_mlockall
184	aio_statvfs	183	aio_statvfs
…		…
202		201
203	=head1 FUNCTIONS	202	=head1 FUNCTIONS
204		203
205	=head2 QUICK OVERVIEW	204	=head2 QUICK OVERVIEW
206		205
207	This section simply lists the prototypes of the most important functions	206	This section simply lists the prototypes most of the functions for
208	for quick reference. See the following sections for function-by-function	207	quick reference. See the following sections for function-by-function
209	documentation.	208	documentation.
210		209
211	aio_wd $pathname, $callback->($wd)	210	aio_wd $pathname, $callback->($wd)
212	aio_open $pathname, $flags, $mode, $callback->($fh)	211	aio_open $pathname, $flags, $mode, $callback->($fh)
213	aio_close $fh, $callback->($status)	212	aio_close $fh, $callback->($status)
		213	aio_seek $fh,$offset,$whence, $callback->($offs)
214	aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)	214	aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
215	aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)	215	aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
216	aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval)	216	aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval)
217	aio_readahead $fh,$offset,$length, $callback->($retval)	217	aio_readahead $fh,$offset,$length, $callback->($retval)
218	aio_stat $fh_or_path, $callback->($status)	218	aio_stat $fh_or_path, $callback->($status)
219	aio_lstat $fh, $callback->($status)	219	aio_lstat $fh, $callback->($status)
220	aio_statvfs $fh_or_path, $callback->($statvfs)	220	aio_statvfs $fh_or_path, $callback->($statvfs)
221	aio_utime $fh_or_path, $atime, $mtime, $callback->($status)	221	aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
222	aio_chown $fh_or_path, $uid, $gid, $callback->($status)	222	aio_chown $fh_or_path, $uid, $gid, $callback->($status)
		223	aio_chmod $fh_or_path, $mode, $callback->($status)
223	aio_truncate $fh_or_path, $offset, $callback->($status)	224	aio_truncate $fh_or_path, $offset, $callback->($status)
224	aio_chmod $fh_or_path, $mode, $callback->($status)	225	aio_allocate $fh, $mode, $offset, $len, $callback->($status)
		226	aio_fiemap $fh, $start, $length, $flags, $count, $cb->(\@extents)
225	aio_unlink $pathname, $callback->($status)	227	aio_unlink $pathname, $callback->($status)
226	aio_mknod $pathname, $mode, $dev, $callback->($status)	228	aio_mknod $pathname, $mode, $dev, $callback->($status)
227	aio_link $srcpath, $dstpath, $callback->($status)	229	aio_link $srcpath, $dstpath, $callback->($status)
228	aio_symlink $srcpath, $dstpath, $callback->($status)	230	aio_symlink $srcpath, $dstpath, $callback->($status)
229	aio_readlink $pathname, $callback->($link)	231	aio_readlink $pathname, $callback->($link)
230	aio_realpath $pathname, $callback->($link)	232	aio_realpath $pathname, $callback->($path)
231	aio_rename $srcpath, $dstpath, $callback->($status)	233	aio_rename $srcpath, $dstpath, $callback->($status)
232	aio_mkdir $pathname, $mode, $callback->($status)	234	aio_mkdir $pathname, $mode, $callback->($status)
233	aio_rmdir $pathname, $callback->($status)	235	aio_rmdir $pathname, $callback->($status)
234	aio_readdir $pathname, $callback->($entries)	236	aio_readdir $pathname, $callback->($entries)
235	aio_readdirx $pathname, $flags, $callback->($entries, $flags)	237	aio_readdirx $pathname, $flags, $callback->($entries, $flags)
…		…
238	aio_scandir $pathname, $maxreq, $callback->($dirs, $nondirs)	240	aio_scandir $pathname, $maxreq, $callback->($dirs, $nondirs)
239	aio_load $pathname, $data, $callback->($status)	241	aio_load $pathname, $data, $callback->($status)
240	aio_copy $srcpath, $dstpath, $callback->($status)	242	aio_copy $srcpath, $dstpath, $callback->($status)
241	aio_move $srcpath, $dstpath, $callback->($status)	243	aio_move $srcpath, $dstpath, $callback->($status)
242	aio_rmtree $pathname, $callback->($status)	244	aio_rmtree $pathname, $callback->($status)
		245	aio_fcntl $fh, $cmd, $arg, $callback->($status)
		246	aio_ioctl $fh, $request, $buf, $callback->($status)
243	aio_sync $callback->($status)	247	aio_sync $callback->($status)
244	aio_syncfs $fh, $callback->($status)	248	aio_syncfs $fh, $callback->($status)
245	aio_fsync $fh, $callback->($status)	249	aio_fsync $fh, $callback->($status)
246	aio_fdatasync $fh, $callback->($status)	250	aio_fdatasync $fh, $callback->($status)
247	aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status)	251	aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status)
…		…
271	IO::AIO::nready	275	IO::AIO::nready
272	IO::AIO::npending	276	IO::AIO::npending
273		277
274	IO::AIO::sendfile $ofh, $ifh, $offset, $count	278	IO::AIO::sendfile $ofh, $ifh, $offset, $count
275	IO::AIO::fadvise $fh, $offset, $len, $advice	279	IO::AIO::fadvise $fh, $offset, $len, $advice
		280	IO::AIO::mmap $scalar, $length, $prot, $flags[, $fh[, $offset]]
		281	IO::AIO::munmap $scalar
276	IO::AIO::madvise $scalar, $offset, $length, $advice	282	IO::AIO::madvise $scalar, $offset, $length, $advice
277	IO::AIO::mprotect $scalar, $offset, $length, $protect	283	IO::AIO::mprotect $scalar, $offset, $length, $protect
278	IO::AIO::munlock $scalar, $offset = 0, $length = undef	284	IO::AIO::munlock $scalar, $offset = 0, $length = undef
279	IO::AIO::munlockall	285	IO::AIO::munlockall
280		286
281	=head2 AIO REQUEST FUNCTIONS	287	=head2 API NOTES
282		288
283	All the C<aio_*> calls are more or less thin wrappers around the syscall	289	All the C<aio_*> calls are more or less thin wrappers around the syscall
284	with the same name (sans C<aio_>). The arguments are similar or identical,	290	with the same name (sans C<aio_>). The arguments are similar or identical,
285	and they all accept an additional (and optional) C<$callback> argument	291	and they all accept an additional (and optional) C<$callback> argument
286	which must be a code reference. This code reference will be called after	292	which must be a code reference. This code reference will be called after
…		…
317	correct contents.	323	correct contents.
318		324
319	This works, btw. independent of the internal UTF-8 bit, which IO::AIO	325	This works, btw. independent of the internal UTF-8 bit, which IO::AIO
320	handles correctly whether it is set or not.	326	handles correctly whether it is set or not.
321		327
		328	=head2 AIO REQUEST FUNCTIONS
		329
322	=over 4	330	=over 4
323		331
324	=item $prev_pri = aioreq_pri [$pri]	332	=item $prev_pri = aioreq_pri [$pri]
325		333
326	Returns the priority value that would be used for the next request and, if	334	Returns the priority value that would be used for the next request and, if
…		…
355		363
356		364
357	=item aio_open $pathname, $flags, $mode, $callback->($fh)	365	=item aio_open $pathname, $flags, $mode, $callback->($fh)
358		366
359	Asynchronously open or create a file and call the callback with a newly	367	Asynchronously open or create a file and call the callback with a newly
360	created filehandle for the file.	368	created filehandle for the file (or C<undef> in case of an error).
361		369
362	The pathname passed to C<aio_open> must be absolute. See API NOTES, above,	370	The pathname passed to C<aio_open> must be absolute. See API NOTES, above,
363	for an explanation.	371	for an explanation.
364		372
365	The C<$flags> argument is a bitmask. See the C<Fcntl> module for a	373	The C<$flags> argument is a bitmask. See the C<Fcntl> module for a
…		…
388	following POSIX and non-POSIX constants are available (missing ones on	396	following POSIX and non-POSIX constants are available (missing ones on
389	your system are, as usual, C<0>):	397	your system are, as usual, C<0>):
390		398
391	C<O_ASYNC>, C<O_DIRECT>, C<O_NOATIME>, C<O_CLOEXEC>, C<O_NOCTTY>, C<O_NOFOLLOW>,	399	C<O_ASYNC>, C<O_DIRECT>, C<O_NOATIME>, C<O_CLOEXEC>, C<O_NOCTTY>, C<O_NOFOLLOW>,
392	C<O_NONBLOCK>, C<O_EXEC>, C<O_SEARCH>, C<O_DIRECTORY>, C<O_DSYNC>,	400	C<O_NONBLOCK>, C<O_EXEC>, C<O_SEARCH>, C<O_DIRECTORY>, C<O_DSYNC>,
393	C<O_RSYNC>, C<O_SYNC> and C<O_TTY_INIT>.	401	C<O_RSYNC>, C<O_SYNC>, C<O_PATH>, C<O_TMPFILE>, and C<O_TTY_INIT>.
394		402
395		403
396	=item aio_close $fh, $callback->($status)	404	=item aio_close $fh, $callback->($status)
397		405
398	Asynchronously close a file and call the callback with the result	406	Asynchronously close a file and call the callback with the result
…		…
407		415
408	Or in other words: the file descriptor will be closed, but it will not be	416	Or in other words: the file descriptor will be closed, but it will not be
409	free for reuse until the perl filehandle is closed.	417	free for reuse until the perl filehandle is closed.
410		418
411	=cut	419	=cut
		420
		421	=item aio_seek $fh, $offset, $whence, $callback->($offs)
		422
		423	Seeks the filehandle to the new C<$offset>, similarly to perl's
		424	C<sysseek>. The C<$whence> can use the traditional values (C<0> for
		425	C<IO::AIO::SEEK_SET>, C<1> for C<IO::AIO::SEEK_CUR> or C<2> for
		426	C<IO::AIO::SEEK_END>).
		427
		428	The resulting absolute offset will be passed to the callback, or C<-1> in
		429	case of an error.
		430
		431	In theory, the C<$whence> constants could be different than the
		432	corresponding values from L<Fcntl>, but perl guarantees they are the same,
		433	so don't panic.
		434
		435	As a GNU/Linux (and maybe Solaris) extension, also the constants
		436	C<IO::AIO::SEEK_DATA> and C<IO::AIO::SEEK_HOLE> are available, if they
		437	could be found. No guarantees about suitability for use in C<aio_seek> or
		438	Perl's C<sysseek> can be made though, although I would naively assume they
		439	"just work".
412		440
413	=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)	441	=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
414		442
415	=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)	443	=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
416		444
…		…
496	whole pages, so that offset is effectively rounded down to a page boundary	524	whole pages, so that offset is effectively rounded down to a page boundary
497	and bytes are read up to the next page boundary greater than or equal to	525	and bytes are read up to the next page boundary greater than or equal to
498	(off-set+length). C<aio_readahead> does not read beyond the end of the	526	(off-set+length). C<aio_readahead> does not read beyond the end of the
499	file. The current file offset of the file is left unchanged.	527	file. The current file offset of the file is left unchanged.
500		528
501	If that syscall doesn't exist (likely if your OS isn't Linux) it will be	529	If that syscall doesn't exist (likely if your kernel isn't Linux) it will
502	emulated by simply reading the data, which would have a similar effect.	530	be emulated by simply reading the data, which would have a similar effect.
503		531
504		532
505	=item aio_stat $fh_or_path, $callback->($status)	533	=item aio_stat $fh_or_path, $callback->($status)
506		534
507	=item aio_lstat $fh, $callback->($status)	535	=item aio_lstat $fh, $callback->($status)
…		…
576	namemax => 255,	604	namemax => 255,
577	frsize => 1024,	605	frsize => 1024,
578	fsid => 1810	606	fsid => 1810
579	}	607	}
580		608
		609	Here is a (likely partial - send me updates!) list of fsid values used by
		610	Linux - it is safe to hardcode these when C<$^O> is C<linux>:
		611
		612	0x0000adf5 adfs
		613	0x0000adff affs
		614	0x5346414f afs
		615	0x09041934 anon-inode filesystem
		616	0x00000187 autofs
		617	0x42465331 befs
		618	0x1badface bfs
		619	0x42494e4d binfmt_misc
		620	0x9123683e btrfs
		621	0x0027e0eb cgroupfs
		622	0xff534d42 cifs
		623	0x73757245 coda
		624	0x012ff7b7 coh
		625	0x28cd3d45 cramfs
		626	0x453dcd28 cramfs-wend (wrong endianness)
		627	0x64626720 debugfs
		628	0x00001373 devfs
		629	0x00001cd1 devpts
		630	0x0000f15f ecryptfs
		631	0x00414a53 efs
		632	0x0000137d ext
		633	0x0000ef53 ext2/ext3/ext4
		634	0x0000ef51 ext2
		635	0xf2f52010 f2fs
		636	0x00004006 fat
		637	0x65735546 fuseblk
		638	0x65735543 fusectl
		639	0x0bad1dea futexfs
		640	0x01161970 gfs2
		641	0x47504653 gpfs
		642	0x00004244 hfs
		643	0xf995e849 hpfs
		644	0x00c0ffee hostfs
		645	0x958458f6 hugetlbfs
		646	0x2bad1dea inotifyfs
		647	0x00009660 isofs
		648	0x000072b6 jffs2
		649	0x3153464a jfs
		650	0x6b414653 k-afs
		651	0x0bd00bd0 lustre
		652	0x0000137f minix
		653	0x0000138f minix 30 char names
		654	0x00002468 minix v2
		655	0x00002478 minix v2 30 char names
		656	0x00004d5a minix v3
		657	0x19800202 mqueue
		658	0x00004d44 msdos
		659	0x0000564c novell
		660	0x00006969 nfs
		661	0x6e667364 nfsd
		662	0x00003434 nilfs
		663	0x5346544e ntfs
		664	0x00009fa1 openprom
		665	0x7461636F ocfs2
		666	0x00009fa0 proc
		667	0x6165676c pstorefs
		668	0x0000002f qnx4
		669	0x68191122 qnx6
		670	0x858458f6 ramfs
		671	0x52654973 reiserfs
		672	0x00007275 romfs
		673	0x67596969 rpc_pipefs
		674	0x73636673 securityfs
		675	0xf97cff8c selinux
		676	0x0000517b smb
		677	0x534f434b sockfs
		678	0x73717368 squashfs
		679	0x62656572 sysfs
		680	0x012ff7b6 sysv2
		681	0x012ff7b5 sysv4
		682	0x01021994 tmpfs
		683	0x15013346 udf
		684	0x00011954 ufs
		685	0x54190100 ufs byteswapped
		686	0x00009fa2 usbdevfs
		687	0x01021997 v9fs
		688	0xa501fcf5 vxfs
		689	0xabba1974 xenfs
		690	0x012ff7b4 xenix
		691	0x58465342 xfs
		692	0x012fd16d xia
581		693
582	=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status)	694	=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
583		695
584	Works like perl's C<utime> function (including the special case of $atime	696	Works like perl's C<utime> function (including the special case of $atime
585	and $mtime being undef). Fractional times are supported if the underlying	697	and $mtime being undef). Fractional times are supported if the underlying
…		…
613	=item aio_truncate $fh_or_path, $offset, $callback->($status)	725	=item aio_truncate $fh_or_path, $offset, $callback->($status)
614		726
615	Works like truncate(2) or ftruncate(2).	727	Works like truncate(2) or ftruncate(2).
616		728
617		729
		730	=item aio_allocate $fh, $mode, $offset, $len, $callback->($status)
		731
		732	Allocates or frees disk space according to the C<$mode> argument. See the
		733	linux C<fallocate> documentation for details.
		734
		735	C<$mode> is usually C<0> or C<IO::AIO::FALLOC_FL_KEEP_SIZE> to allocate
		736	space, or C<IO::AIO::FALLOC_FL_PUNCH_HOLE \| IO::AIO::FALLOC_FL_KEEP_SIZE>,
		737	to deallocate a file range.
		738
		739	IO::AIO also supports C<FALLOC_FL_COLLAPSE_RANGE>, to remove a range
		740	(without leaving a hole) and C<FALLOC_FL_ZERO_RANGE>, to zero a range (see
		741	your L<fallocate(2)> manpage).
		742
		743	The file system block size used by C<fallocate> is presumably the
		744	C<f_bsize> returned by C<statvfs>.
		745
		746	If C<fallocate> isn't available or cannot be emulated (currently no
		747	emulation will be attempted), passes C<-1> and sets C<$!> to C<ENOSYS>.
		748
		749
618	=item aio_chmod $fh_or_path, $mode, $callback->($status)	750	=item aio_chmod $fh_or_path, $mode, $callback->($status)
619		751
620	Works like perl's C<chmod> function.	752	Works like perl's C<chmod> function.
621		753
622		754
…		…
659		791
660		792
661	=item aio_realpath $pathname, $callback->($path)	793	=item aio_realpath $pathname, $callback->($path)
662		794
663	Asynchronously make the path absolute and resolve any symlinks in	795	Asynchronously make the path absolute and resolve any symlinks in
664	C<$path>. The resulting path only consists of directories (Same as	796	C<$path>. The resulting path only consists of directories (same as
665	L<Cwd::realpath>).	797	L<Cwd::realpath>).
666		798
667	This request can be used to get the absolute path of the current working	799	This request can be used to get the absolute path of the current working
668	directory by passing it a path of F<.> (a single dot).	800	directory by passing it a path of F<.> (a single dot).
669		801
670		802
671	=item aio_rename $srcpath, $dstpath, $callback->($status)	803	=item aio_rename $srcpath, $dstpath, $callback->($status)
672		804
673	Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as	805	Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as
674	rename(2) and call the callback with the result code.	806	rename(2) and call the callback with the result code.
		807
		808	On systems that support the AIO::WD working directory abstraction
		809	natively, the case C<[$wd, "."]> as C<$srcpath> is specialcased - instead
		810	of failing, C<rename> is called on the absolute path of C<$wd>.
675		811
676		812
677	=item aio_mkdir $pathname, $mode, $callback->($status)	813	=item aio_mkdir $pathname, $mode, $callback->($status)
678		814
679	Asynchronously mkdir (create) a directory and call the callback with	815	Asynchronously mkdir (create) a directory and call the callback with
…		…
683		819
684	=item aio_rmdir $pathname, $callback->($status)	820	=item aio_rmdir $pathname, $callback->($status)
685		821
686	Asynchronously rmdir (delete) a directory and call the callback with the	822	Asynchronously rmdir (delete) a directory and call the callback with the
687	result code.	823	result code.
		824
		825	On systems that support the AIO::WD working directory abstraction
		826	natively, the case C<[$wd, "."]> is specialcased - instead of failing,
		827	C<rmdir> is called on the absolute path of C<$wd>.
688		828
689		829
690	=item aio_readdir $pathname, $callback->($entries)	830	=item aio_readdir $pathname, $callback->($entries)
691		831
692	Unlike the POSIX call of the same name, C<aio_readdir> reads an entire	832	Unlike the POSIX call of the same name, C<aio_readdir> reads an entire
…		…
1057	}	1197	}
1058		1198
1059	=item aio_rmtree $pathname, $callback->($status)	1199	=item aio_rmtree $pathname, $callback->($status)
1060		1200
1061	Delete a directory tree starting (and including) C<$path>, return the	1201	Delete a directory tree starting (and including) C<$path>, return the
1062	status of the final C<rmdir> only. This is a composite request that	1202	status of the final C<rmdir> only. This is a composite request that
1063	uses C<aio_scandir> to recurse into and rmdir directories, and unlink	1203	uses C<aio_scandir> to recurse into and rmdir directories, and unlink
1064	everything else.	1204	everything else.
1065		1205
1066	=cut	1206	=cut
1067		1207
…		…
1088	add $grp $dirgrp;	1228	add $grp $dirgrp;
1089	};	1229	};
1090		1230
1091	$grp	1231	$grp
1092	}	1232	}
		1233
		1234	=item aio_fcntl $fh, $cmd, $arg, $callback->($status)
		1235
		1236	=item aio_ioctl $fh, $request, $buf, $callback->($status)
		1237
		1238	These work just like the C<fcntl> and C<ioctl> built-in functions, except
		1239	they execute asynchronously and pass the return value to the callback.
		1240
		1241	Both calls can be used for a lot of things, some of which make more sense
		1242	to run asynchronously in their own thread, while some others make less
		1243	sense. For example, calls that block waiting for external events, such
		1244	as locking, will also lock down an I/O thread while it is waiting, which
		1245	can deadlock the whole I/O system. At the same time, there might be no
		1246	alternative to using a thread to wait.
		1247
		1248	So in general, you should only use these calls for things that do
		1249	(filesystem) I/O, not for things that wait for other events (network,
		1250	other processes), although if you are careful and know what you are doing,
		1251	you still can.
1093		1252
1094	=item aio_sync $callback->($status)	1253	=item aio_sync $callback->($status)
1095		1254
1096	Asynchronously call sync and call the callback when finished.	1255	Asynchronously call sync and call the callback when finished.
1097		1256
…		…
1187		1346
1188	This is a rather advanced IO::AIO call, which works best on mmap(2)ed	1347	This is a rather advanced IO::AIO call, which works best on mmap(2)ed
1189	scalars.	1348	scalars.
1190		1349
1191	It touches (reads or writes) all memory pages in the specified	1350	It touches (reads or writes) all memory pages in the specified
1192	range inside the scalar. All caveats and parameters are the same	1351	range inside the scalar. All caveats and parameters are the same
1193	as for C<aio_msync>, above, except for flags, which must be either	1352	as for C<aio_msync>, above, except for flags, which must be either
1194	C<0> (which reads all pages and ensures they are instantiated) or	1353	C<0> (which reads all pages and ensures they are instantiated) or
1195	C<IO::AIO::MT_MODIFY>, which modifies the memory page s(by reading and	1354	C<IO::AIO::MT_MODIFY>, which modifies the memory pages (by reading and
1196	writing an octet from it, which dirties the page).	1355	writing an octet from it, which dirties the page).
1197		1356
1198	=item aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status)	1357	=item aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status)
1199		1358
1200	This is a rather advanced IO::AIO call, which works best on mmap(2)ed	1359	This is a rather advanced IO::AIO call, which works best on mmap(2)ed
…		…
1231	documented under L<MISCELLANEOUS FUNCTIONS>.	1390	documented under L<MISCELLANEOUS FUNCTIONS>.
1232		1391
1233	Example: asynchronously lock all current and future pages into memory.	1392	Example: asynchronously lock all current and future pages into memory.
1234		1393
1235	aio_mlockall IO::AIO::MCL_FUTURE;	1394	aio_mlockall IO::AIO::MCL_FUTURE;
		1395
		1396	=item aio_fiemap $fh, $start, $length, $flags, $count, $cb->(\@extents)
		1397
		1398	Queries the extents of the given file (by calling the Linux C<FIEMAP>
		1399	ioctl, see L<http://cvs.schmorp.de/IO-AIO/doc/fiemap.txt> for details). If
		1400	the ioctl is not available on your OS, then this request will fail with
		1401	C<ENOSYS>.
		1402
		1403	C<$start> is the starting offset to query extents for, C<$length> is the
		1404	size of the range to query - if it is C<undef>, then the whole file will
		1405	be queried.
		1406
		1407	C<$flags> is a combination of flags (C<IO::AIO::FIEMAP_FLAG_SYNC> or
		1408	C<IO::AIO::FIEMAP_FLAG_XATTR> - C<IO::AIO::FIEMAP_FLAGS_COMPAT> is also
		1409	exported), and is normally C<0> or C<IO::AIO::FIEMAP_FLAG_SYNC> to query
		1410	the data portion.
		1411
		1412	C<$count> is the maximum number of extent records to return. If it is
		1413	C<undef>, then IO::AIO queries all extents of the range. As a very special
		1414	case, if it is C<0>, then the callback receives the number of extents
		1415	instead of the extents themselves (which is unreliable, see below).
		1416
		1417	If an error occurs, the callback receives no arguments. The special
		1418	C<errno> value C<IO::AIO::EBADR> is available to test for flag errors.
		1419
		1420	Otherwise, the callback receives an array reference with extent
		1421	structures. Each extent structure is an array reference itself, with the
		1422	following members:
		1423
		1424	[$logical, $physical, $length, $flags]
		1425
		1426	Flags is any combination of the following flag values (typically either C<0>
		1427	or C<IO::AIO::FIEMAP_EXTENT_LAST> (1)):
		1428
		1429	C<IO::AIO::FIEMAP_EXTENT_LAST>, C<IO::AIO::FIEMAP_EXTENT_UNKNOWN>,
		1430	C<IO::AIO::FIEMAP_EXTENT_DELALLOC>, C<IO::AIO::FIEMAP_EXTENT_ENCODED>,
		1431	C<IO::AIO::FIEMAP_EXTENT_DATA_ENCRYPTED>, C<IO::AIO::FIEMAP_EXTENT_NOT_ALIGNED>,
		1432	C<IO::AIO::FIEMAP_EXTENT_DATA_INLINE>, C<IO::AIO::FIEMAP_EXTENT_DATA_TAIL>,
		1433	C<IO::AIO::FIEMAP_EXTENT_UNWRITTEN>, C<IO::AIO::FIEMAP_EXTENT_MERGED> or
		1434	C<IO::AIO::FIEMAP_EXTENT_SHARED>.
		1435
		1436	At the time of this writing (Linux 3.2), this requets is unreliable unless
		1437	C<$count> is C<undef>, as the kernel has all sorts of bugs preventing
		1438	it to return all extents of a range for files with large number of
		1439	extents. The code works around all these issues if C<$count> is undef.
1236		1440
1237	=item aio_group $callback->(...)	1441	=item aio_group $callback->(...)
1238		1442
1239	This is a very special aio request: Instead of doing something, it is a	1443	This is a very special aio request: Instead of doing something, it is a
1240	container for other aio requests, which is useful if you want to bundle	1444	container for other aio requests, which is useful if you want to bundle
…		…
1324	aio_stat [$etcdir, "passwd"], sub {	1528	aio_stat [$etcdir, "passwd"], sub {
1325	# yay	1529	# yay
1326	};	1530	};
1327	};	1531	};
1328		1532
1329	That C<aio_wd> is a request and not a normal function shows that creating	1533	The fact that C<aio_wd> is a request and not a normal function shows that
1330	an IO::AIO::WD object is itself a potentially blocking operation, which is	1534	creating an IO::AIO::WD object is itself a potentially blocking operation,
1331	why it is done asynchronously.	1535	which is why it is done asynchronously.
1332		1536
1333	To stat the directory obtained with C<aio_wd> above, one could write	1537	To stat the directory obtained with C<aio_wd> above, one could write
1334	either of the following three request calls:	1538	either of the following three request calls:
1335		1539
1336	aio_lstat "/etc" , sub { ... # pathname as normal string	1540	aio_lstat "/etc" , sub { ... # pathname as normal string
…		…
1356	will still point to the original directory. Most functions accepting a	1560	will still point to the original directory. Most functions accepting a
1357	pathname will use the directory fd on newer systems, and the string on	1561	pathname will use the directory fd on newer systems, and the string on
1358	older systems. Some functions (such as realpath) will always rely on the	1562	older systems. Some functions (such as realpath) will always rely on the
1359	string form of the pathname.	1563	string form of the pathname.
1360		1564
1361	So this fucntionality is mainly useful to get some protection against	1565	So this functionality is mainly useful to get some protection against
1362	C<chdir>, to easily get an absolute path out of a relative path for future	1566	C<chdir>, to easily get an absolute path out of a relative path for future
1363	reference, and to speed up doing many operations in the same directory	1567	reference, and to speed up doing many operations in the same directory
1364	(e.g. when stat'ing all files in a directory).	1568	(e.g. when stat'ing all files in a directory).
1365		1569
1366	The following functions implement this working directory abstraction:	1570	The following functions implement this working directory abstraction:
…		…
1379	passing C<undef> as working directory component of a pathname fails the	1583	passing C<undef> as working directory component of a pathname fails the
1380	request with C<ENOENT>, there is often no need for error checking in the	1584	request with C<ENOENT>, there is often no need for error checking in the
1381	C<aio_wd> callback, as future requests using the value will fail in the	1585	C<aio_wd> callback, as future requests using the value will fail in the
1382	expected way.	1586	expected way.
1383		1587
1384	If this call isn't available because your OS lacks it or it couldn't be
1385	detected, it will be emulated by calling C<fsync> instead.
1386
1387	=item IO::AIO::CWD	1588	=item IO::AIO::CWD
1388		1589
1389	This is a compiletime constant (object) that represents the process	1590	This is a compiletime constant (object) that represents the process
1390	current working directory.	1591	current working directory.
1391		1592
1392	Specifying this object as working directory object for a pathname is as	1593	Specifying this object as working directory object for a pathname is as if
1393	if the pathname would be specified directly, without a directory object,	1594	the pathname would be specified directly, without a directory object. For
1394	e.g., these calls are functionally identical:	1595	example, these calls are functionally identical:
1395		1596
1396	aio_stat "somefile", sub { ... };	1597	aio_stat "somefile", sub { ... };
1397	aio_stat [IO::AIO::CWD, "somefile"], sub { ... };	1598	aio_stat [IO::AIO::CWD, "somefile"], sub { ... };
1398		1599
1399	=back	1600	=back
1400		1601
		1602	To recover the path associated with an IO::AIO::WD object, you can use
		1603	C<aio_realpath>:
		1604
		1605	aio_realpath $wd, sub {
		1606	warn "path is $_[0]\n";
		1607	};
		1608
		1609	Currently, C<aio_statvfs> always, and C<aio_rename> and C<aio_rmdir>
		1610	sometimes, fall back to using an absolue path.
1401		1611
1402	=head2 IO::AIO::REQ CLASS	1612	=head2 IO::AIO::REQ CLASS
1403		1613
1404	All non-aggregate C<aio_*> functions return an object of this class when	1614	All non-aggregate C<aio_*> functions return an object of this class when
1405	called in non-void context.	1615	called in non-void context.
…		…
1583		1793
1584	See C<poll_cb> for an example.	1794	See C<poll_cb> for an example.
1585		1795
1586	=item IO::AIO::poll_cb	1796	=item IO::AIO::poll_cb
1587		1797
1588	Process some outstanding events on the result pipe. You have to call	1798	Process some requests that have reached the result phase (i.e. they have
		1799	been executed but the results are not yet reported). You have to call
		1800	this "regularly" to finish outstanding requests.
		1801
1589	this regularly. Returns C<0> if all events could be processed (or there	1802	Returns C<0> if all events could be processed (or there were no
1590	were no events to process), or C<-1> if it returned earlier for whatever	1803	events to process), or C<-1> if it returned earlier for whatever
1591	reason. Returns immediately when no events are outstanding. The amount of	1804	reason. Returns immediately when no events are outstanding. The amount
1592	events processed depends on the settings of C<IO::AIO::max_poll_req> and	1805	of events processed depends on the settings of C<IO::AIO::max_poll_req>,
1593	C<IO::AIO::max_poll_time>.	1806	C<IO::AIO::max_poll_time> and C<IO::AIO::max_outstanding>.
1594		1807
1595	If not all requests were processed for whatever reason, the filehandle	1808	If not all requests were processed for whatever reason, the poll file
1596	will still be ready when C<poll_cb> returns, so normally you don't have to	1809	descriptor will still be ready when C<poll_cb> returns, so normally you
1597	do anything special to have it called later.	1810	don't have to do anything special to have it called later.
1598		1811
1599	Apart from calling C<IO::AIO::poll_cb> when the event filehandle becomes	1812	Apart from calling C<IO::AIO::poll_cb> when the event filehandle becomes
1600	ready, it can be beneficial to call this function from loops which submit	1813	ready, it can be beneficial to call this function from loops which submit
1601	a lot of requests, to make sure the results get processed when they become	1814	a lot of requests, to make sure the results get processed when they become
1602	available and not just when the loop is finished and the event loop takes	1815	available and not just when the loop is finished and the event loop takes
…		…
1611	poll => 'r', async => 1,	1824	poll => 'r', async => 1,
1612	cb => \&IO::AIO::poll_cb);	1825	cb => \&IO::AIO::poll_cb);
1613		1826
1614	=item IO::AIO::poll_wait	1827	=item IO::AIO::poll_wait
1615		1828
1616	If there are any outstanding requests and none of them in the result	1829	Wait until either at least one request is in the result phase or no
1617	phase, wait till the result filehandle becomes ready for reading (simply	1830	requests are outstanding anymore.
1618	does a C<select> on the filehandle. This is useful if you want to	1831
1619	synchronously wait for some requests to finish).	1832	This is useful if you want to synchronously wait for some requests to
		1833	become ready, without actually handling them.
1620		1834
1621	See C<nreqs> for an example.	1835	See C<nreqs> for an example.
1622		1836
1623	=item IO::AIO::poll	1837	=item IO::AIO::poll
1624		1838
…		…
1745		1959
1746	This is a very bad function to use in interactive programs because it	1960	This is a very bad function to use in interactive programs because it
1747	blocks, and a bad way to reduce concurrency because it is inexact: Better	1961	blocks, and a bad way to reduce concurrency because it is inexact: Better
1748	use an C<aio_group> together with a feed callback.	1962	use an C<aio_group> together with a feed callback.
1749		1963
1750	It's main use is in scripts without an event loop - when you want to stat	1964	Its main use is in scripts without an event loop - when you want to stat
1751	a lot of files, you can write somehting like this:	1965	a lot of files, you can write somehting like this:
1752		1966
1753	IO::AIO::max_outstanding 32;	1967	IO::AIO::max_outstanding 32;
1754		1968
1755	for my $path (...) {	1969	for my $path (...) {
…		…
1795		2009
1796	=back	2010	=back
1797		2011
1798	=head3 MISCELLANEOUS FUNCTIONS	2012	=head3 MISCELLANEOUS FUNCTIONS
1799		2013
1800	IO::AIO implements some functions that might be useful, but are not	2014	IO::AIO implements some functions that are useful when you want to use
1801	asynchronous.	2015	some "Advanced I/O" function not available to in Perl, without going the
		2016	"Asynchronous I/O" route. Many of these have an asynchronous C<aio_*>
		2017	counterpart.
1802		2018
1803	=over 4	2019	=over 4
1804		2020
1805	=item IO::AIO::sendfile $ofh, $ifh, $offset, $count	2021	=item IO::AIO::sendfile $ofh, $ifh, $offset, $count
1806		2022
…		…
1843	ENOSYS, otherwise the return value of C<mprotect>.	2059	ENOSYS, otherwise the return value of C<mprotect>.
1844		2060
1845	=item IO::AIO::mmap $scalar, $length, $prot, $flags, $fh[, $offset]	2061	=item IO::AIO::mmap $scalar, $length, $prot, $flags, $fh[, $offset]
1846		2062
1847	Memory-maps a file (or anonymous memory range) and attaches it to the	2063	Memory-maps a file (or anonymous memory range) and attaches it to the
1848	given C<$scalar>, which will act like a string scalar.	2064	given C<$scalar>, which will act like a string scalar. Returns true on
		2065	success, and false otherwise.
1849		2066
1850	The only operations allowed on the scalar are C<substr>/C<vec> that don't	2067	The only operations allowed on the scalar are C<substr>/C<vec> that don't
1851	change the string length, and most read-only operations such as copying it	2068	change the string length, and most read-only operations such as copying it
1852	or searching it with regexes and so on.	2069	or searching it with regexes and so on.
1853		2070
…		…
1864	filesize.	2081	filesize.
1865		2082
1866	C<$prot> is a combination of C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_EXEC>,	2083	C<$prot> is a combination of C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_EXEC>,
1867	C<IO::AIO::PROT_READ> and/or C<IO::AIO::PROT_WRITE>,	2084	C<IO::AIO::PROT_READ> and/or C<IO::AIO::PROT_WRITE>,
1868		2085
1869	C<$flags> can be a combination of C<IO::AIO::MAP_SHARED> or	2086	C<$flags> can be a combination of
1870	C<IO::AIO::MAP_PRIVATE>, or a number of system-specific flags (when	2087	C<IO::AIO::MAP_SHARED> or
1871	not available, the are defined as 0): C<IO::AIO::MAP_ANONYMOUS>	2088	C<IO::AIO::MAP_PRIVATE>,
		2089	or a number of system-specific flags (when not available, the are C<0>):
1872	(which is set to C<MAP_ANON> if your system only provides this	2090	C<IO::AIO::MAP_ANONYMOUS> (which is set to C<MAP_ANON> if your system only provides this constant),
1873	constant), C<IO::AIO::MAP_HUGETLB>, C<IO::AIO::MAP_LOCKED>,	2091	C<IO::AIO::MAP_LOCKED>,
1874	C<IO::AIO::MAP_NORESERVE>, C<IO::AIO::MAP_POPULATE> or	2092	C<IO::AIO::MAP_NORESERVE>,
		2093	C<IO::AIO::MAP_POPULATE>,
1875	C<IO::AIO::MAP_NONBLOCK>	2094	C<IO::AIO::MAP_NONBLOCK>,
		2095	C<IO::AIO::MAP_FIXED>,
		2096	C<IO::AIO::MAP_GROWSDOWN>,
		2097	C<IO::AIO::MAP_32BIT>,
		2098	C<IO::AIO::MAP_HUGETLB> or
		2099	C<IO::AIO::MAP_STACK>.
1876		2100
1877	If C<$fh> is C<undef>, then a file descriptor of C<-1> is passed.	2101	If C<$fh> is C<undef>, then a file descriptor of C<-1> is passed.
1878		2102
1879	C<$offset> is the offset from the start of the file - it generally must be	2103	C<$offset> is the offset from the start of the file - it generally must be
1880	a multiple of C<IO::AIO::PAGESIZE> and defaults to C<0>.	2104	a multiple of C<IO::AIO::PAGESIZE> and defaults to C<0>.
…		…
1905		2129
1906	Calls the C<munlockall> function.	2130	Calls the C<munlockall> function.
1907		2131
1908	On systems that do not implement C<munlockall>, this function returns	2132	On systems that do not implement C<munlockall>, this function returns
1909	ENOSYS, otherwise the return value of C<munlockall>.	2133	ENOSYS, otherwise the return value of C<munlockall>.
		2134
		2135	=item IO::AIO::splice $r_fh, $r_off, $w_fh, $w_off, $length, $flags
		2136
		2137	Calls the GNU/Linux C<splice(2)> syscall, if available. If C<$r_off> or
		2138	C<$w_off> are C<undef>, then C<NULL> is passed for these, otherwise they
		2139	should be the file offset.
		2140
		2141	C<$r_fh> and C<$w_fh> should not refer to the same file, as splice might
		2142	silently corrupt the data in this case.
		2143
		2144	The following symbol flag values are available: C<IO::AIO::SPLICE_F_MOVE>,
		2145	C<IO::AIO::SPLICE_F_NONBLOCK>, C<IO::AIO::SPLICE_F_MORE> and
		2146	C<IO::AIO::SPLICE_F_GIFT>.
		2147
		2148	See the C<splice(2)> manpage for details.
		2149
		2150	=item IO::AIO::tee $r_fh, $w_fh, $length, $flags
		2151
		2152	Calls the GNU/Linux C<tee(2)> syscall, see its manpage and the
		2153	description for C<IO::AIO::splice> above for details.
		2154
		2155	=item $actual_size = IO::AIO::pipesize $r_fh[, $new_size]
		2156
		2157	Attempts to query or change the pipe buffer size. Obviously works only
		2158	on pipes, and currently works only on GNU/Linux systems, and fails with
		2159	C<-1>/C<ENOSYS> everywhere else. If anybody knows how to influence pipe buffer
		2160	size on other systems, drop me a note.
		2161
		2162	=item ($rfh, $wfh) = IO::AIO::pipe2 [$flags]
		2163
		2164	This is a direct interface to the Linux L<pipe2(2)> system call. If
		2165	C<$flags> is missing or C<0>, then this should be the same as a call to
		2166	perl's built-in C<pipe> function and create a new pipe, and works on
		2167	systems that lack the pipe2 syscall. On win32, this case invokes C<_pipe
		2168	(..., 4096, O_BINARY)>.
		2169
		2170	If C<$flags> is non-zero, it tries to invoke the pipe2 system call with
		2171	the given flags (Linux 2.6.27, glibc 2.9).
		2172
		2173	On success, the read and write file handles are returned.
		2174
		2175	On error, nothing will be returned. If the pipe2 syscall is missing and
		2176	C<$flags> is non-zero, fails with C<ENOSYS>.
		2177
		2178	Please refer to L<pipe2(2)> for more info on the C<$flags>, but at the
		2179	time of this writing, C<IO::AIO::O_CLOEXEC>, C<IO::AIO::O_NONBLOCK> and
		2180	C<IO::AIO::O_DIRECT> (Linux 3.4, for packet-based pipes) were supported.
1910		2181
1911	=back	2182	=back
1912		2183
1913	=cut	2184	=cut
1914		2185

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Comparing IO-AIO/AIO.pm (file contents): Revision 1.217 by root, Sun Oct 9 22:25:00 2011 UTC vs. Revision 1.261 by root, Sat May 21 04:43:31 2016 UTC

Diff Legend

Comparing IO-AIO/AIO.pm (file contents):
Revision 1.217 by root, Sun Oct 9 22:25:00 2011 UTC vs.
Revision 1.261 by root, Sat May 21 04:43:31 2016 UTC