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

Comparing IO-AIO/AIO.pm (file contents):
Revision 1.227 by root, Tue May 29 03:58:02 2012 UTC vs.
Revision 1.262 by root, Thu Jun 9 03:15:37 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 = '4.15';	172	our $VERSION = 4.34;
174		173
175	our @AIO_REQ = qw(aio_sendfile aio_seek 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 aio_fiemap	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)
…		…
221	aio_statvfs $fh_or_path, $callback->($statvfs)	220	aio_statvfs $fh_or_path, $callback->($statvfs)
222	aio_utime $fh_or_path, $atime, $mtime, $callback->($status)	221	aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
223	aio_chown $fh_or_path, $uid, $gid, $callback->($status)	222	aio_chown $fh_or_path, $uid, $gid, $callback->($status)
224	aio_chmod $fh_or_path, $mode, $callback->($status)	223	aio_chmod $fh_or_path, $mode, $callback->($status)
225	aio_truncate $fh_or_path, $offset, $callback->($status)	224	aio_truncate $fh_or_path, $offset, $callback->($status)
		225	aio_allocate $fh, $mode, $offset, $len, $callback->($status)
		226	aio_fiemap $fh, $start, $length, $flags, $count, $cb->(\@extents)
226	aio_unlink $pathname, $callback->($status)	227	aio_unlink $pathname, $callback->($status)
227	aio_mknod $pathname, $mode, $dev, $callback->($status)	228	aio_mknod $pathname, $mode, $dev, $callback->($status)
228	aio_link $srcpath, $dstpath, $callback->($status)	229	aio_link $srcpath, $dstpath, $callback->($status)
229	aio_symlink $srcpath, $dstpath, $callback->($status)	230	aio_symlink $srcpath, $dstpath, $callback->($status)
230	aio_readlink $pathname, $callback->($link)	231	aio_readlink $pathname, $callback->($link)
231	aio_realpath $pathname, $callback->($link)	232	aio_realpath $pathname, $callback->($path)
232	aio_rename $srcpath, $dstpath, $callback->($status)	233	aio_rename $srcpath, $dstpath, $callback->($status)
233	aio_mkdir $pathname, $mode, $callback->($status)	234	aio_mkdir $pathname, $mode, $callback->($status)
234	aio_rmdir $pathname, $callback->($status)	235	aio_rmdir $pathname, $callback->($status)
235	aio_readdir $pathname, $callback->($entries)	236	aio_readdir $pathname, $callback->($entries)
236	aio_readdirx $pathname, $flags, $callback->($entries, $flags)	237	aio_readdirx $pathname, $flags, $callback->($entries, $flags)
…		…
239	aio_scandir $pathname, $maxreq, $callback->($dirs, $nondirs)	240	aio_scandir $pathname, $maxreq, $callback->($dirs, $nondirs)
240	aio_load $pathname, $data, $callback->($status)	241	aio_load $pathname, $data, $callback->($status)
241	aio_copy $srcpath, $dstpath, $callback->($status)	242	aio_copy $srcpath, $dstpath, $callback->($status)
242	aio_move $srcpath, $dstpath, $callback->($status)	243	aio_move $srcpath, $dstpath, $callback->($status)
243	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)
244	aio_sync $callback->($status)	247	aio_sync $callback->($status)
245	aio_syncfs $fh, $callback->($status)	248	aio_syncfs $fh, $callback->($status)
246	aio_fsync $fh, $callback->($status)	249	aio_fsync $fh, $callback->($status)
247	aio_fdatasync $fh, $callback->($status)	250	aio_fdatasync $fh, $callback->($status)
248	aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status)	251	aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status)
…		…
360		363
361		364
362	=item aio_open $pathname, $flags, $mode, $callback->($fh)	365	=item aio_open $pathname, $flags, $mode, $callback->($fh)
363		366
364	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
365	created filehandle for the file.	368	created filehandle for the file (or C<undef> in case of an error).
366		369
367	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,
368	for an explanation.	371	for an explanation.
369		372
370	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
…		…
393	following POSIX and non-POSIX constants are available (missing ones on	396	following POSIX and non-POSIX constants are available (missing ones on
394	your system are, as usual, C<0>):	397	your system are, as usual, C<0>):
395		398
396	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>,
397	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>,
398	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>.
399		402
400		403
401	=item aio_close $fh, $callback->($status)	404	=item aio_close $fh, $callback->($status)
402		405
403	Asynchronously close a file and call the callback with the result	406	Asynchronously close a file and call the callback with the result
…		…
507	As native sendfile syscalls (as practically any non-POSIX interface hacked	510	As native sendfile syscalls (as practically any non-POSIX interface hacked
508	together in a hurry to improve benchmark numbers) tend to be rather buggy	511	together in a hurry to improve benchmark numbers) tend to be rather buggy
509	on many systems, this implementation tries to work around some known bugs	512	on many systems, this implementation tries to work around some known bugs
510	in Linux and FreeBSD kernels (probably others, too), but that might fail,	513	in Linux and FreeBSD kernels (probably others, too), but that might fail,
511	so you really really should check the return value of C<aio_sendfile> -	514	so you really really should check the return value of C<aio_sendfile> -
512	fewre bytes than expected might have been transferred.	515	fewer bytes than expected might have been transferred.
513		516
514		517
515	=item aio_readahead $fh,$offset,$length, $callback->($retval)	518	=item aio_readahead $fh,$offset,$length, $callback->($retval)
516		519
517	C<aio_readahead> populates the page cache with data from a file so that	520	C<aio_readahead> populates the page cache with data from a file so that
…		…
521	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
522	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
523	(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
524	file. The current file offset of the file is left unchanged.	527	file. The current file offset of the file is left unchanged.
525		528
526	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
527	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.
528		531
529		532
530	=item aio_stat $fh_or_path, $callback->($status)	533	=item aio_stat $fh_or_path, $callback->($status)
531		534
532	=item aio_lstat $fh, $callback->($status)	535	=item aio_lstat $fh, $callback->($status)
…		…
601	namemax => 255,	604	namemax => 255,
602	frsize => 1024,	605	frsize => 1024,
603	fsid => 1810	606	fsid => 1810
604	}	607	}
605		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
606		693
607	=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status)	694	=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
608		695
609	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
610	and $mtime being undef). Fractional times are supported if the underlying	697	and $mtime being undef). Fractional times are supported if the underlying
…		…
638	=item aio_truncate $fh_or_path, $offset, $callback->($status)	725	=item aio_truncate $fh_or_path, $offset, $callback->($status)
639		726
640	Works like truncate(2) or ftruncate(2).	727	Works like truncate(2) or ftruncate(2).
641		728
642		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
643	=item aio_chmod $fh_or_path, $mode, $callback->($status)	750	=item aio_chmod $fh_or_path, $mode, $callback->($status)
644		751
645	Works like perl's C<chmod> function.	752	Works like perl's C<chmod> function.
646		753
647		754
…		…
684		791
685		792
686	=item aio_realpath $pathname, $callback->($path)	793	=item aio_realpath $pathname, $callback->($path)
687		794
688	Asynchronously make the path absolute and resolve any symlinks in	795	Asynchronously make the path absolute and resolve any symlinks in
689	C<$path>. The resulting path only consists of directories (Same as	796	C<$path>. The resulting path only consists of directories (same as
690	L<Cwd::realpath>).	797	L<Cwd::realpath>).
691		798
692	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
693	directory by passing it a path of F<.> (a single dot).	800	directory by passing it a path of F<.> (a single dot).
694		801
695		802
696	=item aio_rename $srcpath, $dstpath, $callback->($status)	803	=item aio_rename $srcpath, $dstpath, $callback->($status)
697		804
698	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
699	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>.
700		811
701		812
702	=item aio_mkdir $pathname, $mode, $callback->($status)	813	=item aio_mkdir $pathname, $mode, $callback->($status)
703		814
704	Asynchronously mkdir (create) a directory and call the callback with	815	Asynchronously mkdir (create) a directory and call the callback with
…		…
708		819
709	=item aio_rmdir $pathname, $callback->($status)	820	=item aio_rmdir $pathname, $callback->($status)
710		821
711	Asynchronously rmdir (delete) a directory and call the callback with the	822	Asynchronously rmdir (delete) a directory and call the callback with the
712	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>.
713		828
714		829
715	=item aio_readdir $pathname, $callback->($entries)	830	=item aio_readdir $pathname, $callback->($entries)
716		831
717	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
…		…
1082	}	1197	}
1083		1198
1084	=item aio_rmtree $pathname, $callback->($status)	1199	=item aio_rmtree $pathname, $callback->($status)
1085		1200
1086	Delete a directory tree starting (and including) C<$path>, return the	1201	Delete a directory tree starting (and including) C<$path>, return the
1087	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
1088	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
1089	everything else.	1204	everything else.
1090		1205
1091	=cut	1206	=cut
1092		1207
…		…
1113	add $grp $dirgrp;	1228	add $grp $dirgrp;
1114	};	1229	};
1115		1230
1116	$grp	1231	$grp
1117	}	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.
1118		1252
1119	=item aio_sync $callback->($status)	1253	=item aio_sync $callback->($status)
1120		1254
1121	Asynchronously call sync and call the callback when finished.	1255	Asynchronously call sync and call the callback when finished.
1122		1256
…		…
1212		1346
1213	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
1214	scalars.	1348	scalars.
1215		1349
1216	It touches (reads or writes) all memory pages in the specified	1350	It touches (reads or writes) all memory pages in the specified
1217	range inside the scalar. All caveats and parameters are the same	1351	range inside the scalar. All caveats and parameters are the same
1218	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
1219	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
1220	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
1221	writing an octet from it, which dirties the page).	1355	writing an octet from it, which dirties the page).
1222		1356
1223	=item aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status)	1357	=item aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status)
1224		1358
1225	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
…		…
1259		1393
1260	aio_mlockall IO::AIO::MCL_FUTURE;	1394	aio_mlockall IO::AIO::MCL_FUTURE;
1261		1395
1262	=item aio_fiemap $fh, $start, $length, $flags, $count, $cb->(\@extents)	1396	=item aio_fiemap $fh, $start, $length, $flags, $count, $cb->(\@extents)
1263		1397
1264	Queries the extents of the given file (by calling the Linux FIEMAP ioctl,	1398	Queries the extents of the given file (by calling the Linux C<FIEMAP>
1265	see L<http://cvs.schmorp.de/IO-AIO/doc/fiemap.txt> for details). If the	1399	ioctl, see L<http://cvs.schmorp.de/IO-AIO/doc/fiemap.txt> for details). If
1266	C<ioctl> is not available on your OS, then this rquiest will fail with	1400	the ioctl is not available on your OS, then this request will fail with
1267	C<ENOSYS>.	1401	C<ENOSYS>.
1268		1402
1269	C<$start> is the starting offset to query extents for, C<$length> is the	1403	C<$start> is the starting offset to query extents for, C<$length> is the
1270	size of the range to query - if it is C<undef>, then the whole file will	1404	size of the range to query - if it is C<undef>, then the whole file will
1271	be queried.	1405	be queried.
…		…
1274	C<IO::AIO::FIEMAP_FLAG_XATTR> - C<IO::AIO::FIEMAP_FLAGS_COMPAT> is also	1408	C<IO::AIO::FIEMAP_FLAG_XATTR> - C<IO::AIO::FIEMAP_FLAGS_COMPAT> is also
1275	exported), and is normally C<0> or C<IO::AIO::FIEMAP_FLAG_SYNC> to query	1409	exported), and is normally C<0> or C<IO::AIO::FIEMAP_FLAG_SYNC> to query
1276	the data portion.	1410	the data portion.
1277		1411
1278	C<$count> is the maximum number of extent records to return. If it is	1412	C<$count> is the maximum number of extent records to return. If it is
1279	C<undef>, then IO::AIO queries all extents of the file. As a very special	1413	C<undef>, then IO::AIO queries all extents of the range. As a very special
1280	case, if it is C<0>, then the callback receives the number of extents	1414	case, if it is C<0>, then the callback receives the number of extents
1281	instead of the extents themselves.	1415	instead of the extents themselves (which is unreliable, see below).
1282		1416
1283	If an error occurs, the callback receives no arguments. The special	1417	If an error occurs, the callback receives no arguments. The special
1284	C<errno> value C<IO::AIO::EBADR> is available to test for flag errors.	1418	C<errno> value C<IO::AIO::EBADR> is available to test for flag errors.
1285		1419
1286	Otherwise, the callback receives an array reference with extent	1420	Otherwise, the callback receives an array reference with extent
…		…
1288	following members:	1422	following members:
1289		1423
1290	[$logical, $physical, $length, $flags]	1424	[$logical, $physical, $length, $flags]
1291		1425
1292	Flags is any combination of the following flag values (typically either C<0>	1426	Flags is any combination of the following flag values (typically either C<0>
1293	or C<IO::AIO::FIEMAP_EXTENT_LAST>):	1427	or C<IO::AIO::FIEMAP_EXTENT_LAST> (1)):
1294		1428
1295	C<IO::AIO::FIEMAP_EXTENT_LAST>, C<IO::AIO::FIEMAP_EXTENT_UNKNOWN>,	1429	C<IO::AIO::FIEMAP_EXTENT_LAST>, C<IO::AIO::FIEMAP_EXTENT_UNKNOWN>,
1296	C<IO::AIO::FIEMAP_EXTENT_DELALLOC>, C<IO::AIO::FIEMAP_EXTENT_ENCODED>,	1430	C<IO::AIO::FIEMAP_EXTENT_DELALLOC>, C<IO::AIO::FIEMAP_EXTENT_ENCODED>,
1297	C<IO::AIO::FIEMAP_EXTENT_DATA_ENCRYPTED>, C<IO::AIO::FIEMAP_EXTENT_NOT_ALIGNED>,	1431	C<IO::AIO::FIEMAP_EXTENT_DATA_ENCRYPTED>, C<IO::AIO::FIEMAP_EXTENT_NOT_ALIGNED>,
1298	C<IO::AIO::FIEMAP_EXTENT_DATA_INLINE>, C<IO::AIO::FIEMAP_EXTENT_DATA_TAIL>,	1432	C<IO::AIO::FIEMAP_EXTENT_DATA_INLINE>, C<IO::AIO::FIEMAP_EXTENT_DATA_TAIL>,
1299	C<IO::AIO::FIEMAP_EXTENT_UNWRITTEN>, C<IO::AIO::FIEMAP_EXTENT_MERGED> or	1433	C<IO::AIO::FIEMAP_EXTENT_UNWRITTEN>, C<IO::AIO::FIEMAP_EXTENT_MERGED> or
1300	C<IO::AIO::FIEMAP_EXTENT_SHARED>.	1434	C<IO::AIO::FIEMAP_EXTENT_SHARED>.
1301		1435
		1436	At the time of this writing (Linux 3.2), this requets is unreliable unless
		1437	C<$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.
		1440
1302	=item aio_group $callback->(...)	1441	=item aio_group $callback->(...)
1303		1442
1304	This is a very special aio request: Instead of doing something, it is a	1443	This is a very special aio request: Instead of doing something, it is a
1305	container for other aio requests, which is useful if you want to bundle	1444	container for other aio requests, which is useful if you want to bundle
1306	many requests into a single, composite, request with a definite callback	1445	many requests into a single, composite, request with a definite callback
…		…
1389	aio_stat [$etcdir, "passwd"], sub {	1528	aio_stat [$etcdir, "passwd"], sub {
1390	# yay	1529	# yay
1391	};	1530	};
1392	};	1531	};
1393		1532
1394	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
1395	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,
1396	why it is done asynchronously.	1535	which is why it is done asynchronously.
1397		1536
1398	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
1399	either of the following three request calls:	1538	either of the following three request calls:
1400		1539
1401	aio_lstat "/etc" , sub { ... # pathname as normal string	1540	aio_lstat "/etc" , sub { ... # pathname as normal string
…		…
1421	will still point to the original directory. Most functions accepting a	1560	will still point to the original directory. Most functions accepting a
1422	pathname will use the directory fd on newer systems, and the string on	1561	pathname will use the directory fd on newer systems, and the string on
1423	older systems. Some functions (such as realpath) will always rely on the	1562	older systems. Some functions (such as realpath) will always rely on the
1424	string form of the pathname.	1563	string form of the pathname.
1425		1564
1426	So this fucntionality is mainly useful to get some protection against	1565	So this functionality is mainly useful to get some protection against
1427	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
1428	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
1429	(e.g. when stat'ing all files in a directory).	1568	(e.g. when stat'ing all files in a directory).
1430		1569
1431	The following functions implement this working directory abstraction:	1570	The following functions implement this working directory abstraction:
…		…
1444	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
1445	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
1446	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
1447	expected way.	1586	expected way.
1448		1587
1449	If this call isn't available because your OS lacks it or it couldn't be
1450	detected, it will be emulated by calling C<fsync> instead.
1451
1452	=item IO::AIO::CWD	1588	=item IO::AIO::CWD
1453		1589
1454	This is a compiletime constant (object) that represents the process	1590	This is a compiletime constant (object) that represents the process
1455	current working directory.	1591	current working directory.
1456		1592
1457	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
1458	if the pathname would be specified directly, without a directory object,	1594	the pathname would be specified directly, without a directory object. For
1459	e.g., these calls are functionally identical:	1595	example, these calls are functionally identical:
1460		1596
1461	aio_stat "somefile", sub { ... };	1597	aio_stat "somefile", sub { ... };
1462	aio_stat [IO::AIO::CWD, "somefile"], sub { ... };	1598	aio_stat [IO::AIO::CWD, "somefile"], sub { ... };
1463		1599
1464	=back	1600	=back
1465		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.
1466		1611
1467	=head2 IO::AIO::REQ CLASS	1612	=head2 IO::AIO::REQ CLASS
1468		1613
1469	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
1470	called in non-void context.	1615	called in non-void context.
…		…
1648		1793
1649	See C<poll_cb> for an example.	1794	See C<poll_cb> for an example.
1650		1795
1651	=item IO::AIO::poll_cb	1796	=item IO::AIO::poll_cb
1652		1797
1653	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
1654	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
1655	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
1656	reason. Returns immediately when no events are outstanding. The amount of	1804	reason. Returns immediately when no events are outstanding. The amount
1657	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>,
1658	C<IO::AIO::max_poll_time>.	1806	C<IO::AIO::max_poll_time> and C<IO::AIO::max_outstanding>.
1659		1807
1660	If not all requests were processed for whatever reason, the filehandle	1808	If not all requests were processed for whatever reason, the poll file
1661	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
1662	do anything special to have it called later.	1810	don't have to do anything special to have it called later.
1663		1811
1664	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
1665	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
1666	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
1667	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
…		…
1676	poll => 'r', async => 1,	1824	poll => 'r', async => 1,
1677	cb => \&IO::AIO::poll_cb);	1825	cb => \&IO::AIO::poll_cb);
1678		1826
1679	=item IO::AIO::poll_wait	1827	=item IO::AIO::poll_wait
1680		1828
1681	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
1682	phase, wait till the result filehandle becomes ready for reading (simply	1830	requests are outstanding anymore.
1683	does a C<select> on the filehandle. This is useful if you want to	1831
1684	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.
1685		1834
1686	See C<nreqs> for an example.	1835	See C<nreqs> for an example.
1687		1836
1688	=item IO::AIO::poll	1837	=item IO::AIO::poll
1689		1838
…		…
1810		1959
1811	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
1812	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
1813	use an C<aio_group> together with a feed callback.	1962	use an C<aio_group> together with a feed callback.
1814		1963
1815	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
1816	a lot of files, you can write somehting like this:	1965	a lot of files, you can write somehting like this:
1817		1966
1818	IO::AIO::max_outstanding 32;	1967	IO::AIO::max_outstanding 32;
1819		1968
1820	for my $path (...) {	1969	for my $path (...) {
…		…
1860		2009
1861	=back	2010	=back
1862		2011
1863	=head3 MISCELLANEOUS FUNCTIONS	2012	=head3 MISCELLANEOUS FUNCTIONS
1864		2013
1865	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
1866	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.
1867		2018
1868	=over 4	2019	=over 4
1869		2020
1870	=item IO::AIO::sendfile $ofh, $ifh, $offset, $count	2021	=item IO::AIO::sendfile $ofh, $ifh, $offset, $count
1871		2022
…		…
1908	ENOSYS, otherwise the return value of C<mprotect>.	2059	ENOSYS, otherwise the return value of C<mprotect>.
1909		2060
1910	=item IO::AIO::mmap $scalar, $length, $prot, $flags, $fh[, $offset]	2061	=item IO::AIO::mmap $scalar, $length, $prot, $flags, $fh[, $offset]
1911		2062
1912	Memory-maps a file (or anonymous memory range) and attaches it to the	2063	Memory-maps a file (or anonymous memory range) and attaches it to the
1913	given C<$scalar>, which will act like a string scalar.	2064	given C<$scalar>, which will act like a string scalar. Returns true on
		2065	success, and false otherwise.
1914		2066
1915	The only operations allowed on the scalar are C<substr>/C<vec> that don't	2067	The only operations allowed on the scalar are C<substr>/C<vec> that don't
1916	change the string length, and most read-only operations such as copying it	2068	change the string length, and most read-only operations such as copying it
1917	or searching it with regexes and so on.	2069	or searching it with regexes and so on.
1918		2070
…		…
1929	filesize.	2081	filesize.
1930		2082
1931	C<$prot> is a combination of C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_EXEC>,	2083	C<$prot> is a combination of C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_EXEC>,
1932	C<IO::AIO::PROT_READ> and/or C<IO::AIO::PROT_WRITE>,	2084	C<IO::AIO::PROT_READ> and/or C<IO::AIO::PROT_WRITE>,
1933		2085
1934	C<$flags> can be a combination of C<IO::AIO::MAP_SHARED> or	2086	C<$flags> can be a combination of
1935	C<IO::AIO::MAP_PRIVATE>, or a number of system-specific flags (when	2087	C<IO::AIO::MAP_SHARED> or
1936	not available, the are defined as 0): C<IO::AIO::MAP_ANONYMOUS>	2088	C<IO::AIO::MAP_PRIVATE>,
		2089	or a number of system-specific flags (when not available, the are C<0>):
1937	(which is set to C<MAP_ANON> if your system only provides this	2090	C<IO::AIO::MAP_ANONYMOUS> (which is set to C<MAP_ANON> if your system only provides this constant),
1938	constant), C<IO::AIO::MAP_HUGETLB>, C<IO::AIO::MAP_LOCKED>,	2091	C<IO::AIO::MAP_LOCKED>,
1939	C<IO::AIO::MAP_NORESERVE>, C<IO::AIO::MAP_POPULATE> or	2092	C<IO::AIO::MAP_NORESERVE>,
		2093	C<IO::AIO::MAP_POPULATE>,
1940	C<IO::AIO::MAP_NONBLOCK>	2094	C<IO::AIO::MAP_NONBLOCK>,
		2095	C<IO::AIO::MAP_FIXED>,
		2096	C<IO::AIO::MAP_GROWSDOWN>,
		2097	C<IO::AIO::MAP_32BIT>,
		2098	C<IO::AIO::MAP_HUGETLB> or
		2099	C<IO::AIO::MAP_STACK>.
1941		2100
1942	If C<$fh> is C<undef>, then a file descriptor of C<-1> is passed.	2101	If C<$fh> is C<undef>, then a file descriptor of C<-1> is passed.
1943		2102
1944	C<$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
1945	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>.
…		…
1988		2147
1989	See the C<splice(2)> manpage for details.	2148	See the C<splice(2)> manpage for details.
1990		2149
1991	=item IO::AIO::tee $r_fh, $w_fh, $length, $flags	2150	=item IO::AIO::tee $r_fh, $w_fh, $length, $flags
1992		2151
1993	Calls the GNU/Linux C<tee(2)> syscall, see it's manpage and the	2152	Calls the GNU/Linux C<tee(2)> syscall, see its manpage and the
1994	description for C<IO::AIO::splice> above for details.	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.
1995		2181
1996	=back	2182	=back
1997		2183
1998	=cut	2184	=cut
1999		2185

Diff Legend

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

Comparing IO-AIO/AIO.pm (file contents): Revision 1.227 by root, Tue May 29 03:58:02 2012 UTC vs. Revision 1.262 by root, Thu Jun 9 03:15:37 2016 UTC

Diff Legend

Comparing IO-AIO/AIO.pm (file contents):
Revision 1.227 by root, Tue May 29 03:58:02 2012 UTC vs.
Revision 1.262 by root, Thu Jun 9 03:15:37 2016 UTC