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

Comparing IO-AIO/AIO.pm (file contents):
Revision 1.230 by root, Fri Jul 27 17:24:06 2012 UTC vs.
Revision 1.259 by root, Tue Feb 23 19:42:43 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 = 4.33;
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
…		…
228	aio_unlink $pathname, $callback->($status)	227	aio_unlink $pathname, $callback->($status)
229	aio_mknod $pathname, $mode, $dev, $callback->($status)	228	aio_mknod $pathname, $mode, $dev, $callback->($status)
230	aio_link $srcpath, $dstpath, $callback->($status)	229	aio_link $srcpath, $dstpath, $callback->($status)
231	aio_symlink $srcpath, $dstpath, $callback->($status)	230	aio_symlink $srcpath, $dstpath, $callback->($status)
232	aio_readlink $pathname, $callback->($link)	231	aio_readlink $pathname, $callback->($link)
233	aio_realpath $pathname, $callback->($link)	232	aio_realpath $pathname, $callback->($path)
234	aio_rename $srcpath, $dstpath, $callback->($status)	233	aio_rename $srcpath, $dstpath, $callback->($status)
235	aio_mkdir $pathname, $mode, $callback->($status)	234	aio_mkdir $pathname, $mode, $callback->($status)
236	aio_rmdir $pathname, $callback->($status)	235	aio_rmdir $pathname, $callback->($status)
237	aio_readdir $pathname, $callback->($entries)	236	aio_readdir $pathname, $callback->($entries)
238	aio_readdirx $pathname, $flags, $callback->($entries, $flags)	237	aio_readdirx $pathname, $flags, $callback->($entries, $flags)
…		…
241	aio_scandir $pathname, $maxreq, $callback->($dirs, $nondirs)	240	aio_scandir $pathname, $maxreq, $callback->($dirs, $nondirs)
242	aio_load $pathname, $data, $callback->($status)	241	aio_load $pathname, $data, $callback->($status)
243	aio_copy $srcpath, $dstpath, $callback->($status)	242	aio_copy $srcpath, $dstpath, $callback->($status)
244	aio_move $srcpath, $dstpath, $callback->($status)	243	aio_move $srcpath, $dstpath, $callback->($status)
245	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)
246	aio_sync $callback->($status)	247	aio_sync $callback->($status)
247	aio_syncfs $fh, $callback->($status)	248	aio_syncfs $fh, $callback->($status)
248	aio_fsync $fh, $callback->($status)	249	aio_fsync $fh, $callback->($status)
249	aio_fdatasync $fh, $callback->($status)	250	aio_fdatasync $fh, $callback->($status)
250	aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status)	251	aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status)
…		…
362		363
363		364
364	=item aio_open $pathname, $flags, $mode, $callback->($fh)	365	=item aio_open $pathname, $flags, $mode, $callback->($fh)
365		366
366	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
367	created filehandle for the file.	368	created filehandle for the file (or C<undef> in case of an error).
368		369
369	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,
370	for an explanation.	371	for an explanation.
371		372
372	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
…		…
395	following POSIX and non-POSIX constants are available (missing ones on	396	following POSIX and non-POSIX constants are available (missing ones on
396	your system are, as usual, C<0>):	397	your system are, as usual, C<0>):
397		398
398	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>,
399	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>,
400	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>.
401		402
402		403
403	=item aio_close $fh, $callback->($status)	404	=item aio_close $fh, $callback->($status)
404		405
405	Asynchronously close a file and call the callback with the result	406	Asynchronously close a file and call the callback with the result
…		…
603	namemax => 255,	604	namemax => 255,
604	frsize => 1024,	605	frsize => 1024,
605	fsid => 1810	606	fsid => 1810
606	}	607	}
607		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
608		693
609	=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status)	694	=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
610		695
611	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
612	and $mtime being undef). Fractional times are supported if the underlying	697	and $mtime being undef). Fractional times are supported if the underlying
…		…
642	Works like truncate(2) or ftruncate(2).	727	Works like truncate(2) or ftruncate(2).
643		728
644		729
645	=item aio_allocate $fh, $mode, $offset, $len, $callback->($status)	730	=item aio_allocate $fh, $mode, $offset, $len, $callback->($status)
646		731
647	Allocates or freed disk space according to the C<$mode> argument. See the	732	Allocates or frees disk space according to the C<$mode> argument. See the
648	linux C<fallocate> docuemntation for details.	733	linux C<fallocate> documentation for details.
649		734
650	C<$mode> can currently be C<0> or C<IO::AIO::FALLOC_FL_KEEP_SIZE>	735	C<$mode> is usually C<0> or C<IO::AIO::FALLOC_FL_KEEP_SIZE> to allocate
651	to allocate space, or C<IO::AIO::FALLOC_FL_PUNCH_HOLE \|	736	space, or C<IO::AIO::FALLOC_FL_PUNCH_HOLE \| IO::AIO::FALLOC_FL_KEEP_SIZE>,
652	IO::AIO::FALLOC_FL_KEEP_SIZE>, to deallocate a file range.	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).
653		742
654	The file system block size used by C<fallocate> is presumably the	743	The file system block size used by C<fallocate> is presumably the
655	C<f_bsize> returned by C<statvfs>.	744	C<f_bsize> returned by C<statvfs>.
656		745
657	If C<fallocate> isn't available or cannot be emulated (currently no	746	If C<fallocate> isn't available or cannot be emulated (currently no
…		…
702		791
703		792
704	=item aio_realpath $pathname, $callback->($path)	793	=item aio_realpath $pathname, $callback->($path)
705		794
706	Asynchronously make the path absolute and resolve any symlinks in	795	Asynchronously make the path absolute and resolve any symlinks in
707	C<$path>. The resulting path only consists of directories (Same as	796	C<$path>. The resulting path only consists of directories (same as
708	L<Cwd::realpath>).	797	L<Cwd::realpath>).
709		798
710	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
711	directory by passing it a path of F<.> (a single dot).	800	directory by passing it a path of F<.> (a single dot).
712		801
713		802
714	=item aio_rename $srcpath, $dstpath, $callback->($status)	803	=item aio_rename $srcpath, $dstpath, $callback->($status)
715		804
716	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
717	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>.
718		811
719		812
720	=item aio_mkdir $pathname, $mode, $callback->($status)	813	=item aio_mkdir $pathname, $mode, $callback->($status)
721		814
722	Asynchronously mkdir (create) a directory and call the callback with	815	Asynchronously mkdir (create) a directory and call the callback with
…		…
726		819
727	=item aio_rmdir $pathname, $callback->($status)	820	=item aio_rmdir $pathname, $callback->($status)
728		821
729	Asynchronously rmdir (delete) a directory and call the callback with the	822	Asynchronously rmdir (delete) a directory and call the callback with the
730	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>.
731		828
732		829
733	=item aio_readdir $pathname, $callback->($entries)	830	=item aio_readdir $pathname, $callback->($entries)
734		831
735	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
…		…
1100	}	1197	}
1101		1198
1102	=item aio_rmtree $pathname, $callback->($status)	1199	=item aio_rmtree $pathname, $callback->($status)
1103		1200
1104	Delete a directory tree starting (and including) C<$path>, return the	1201	Delete a directory tree starting (and including) C<$path>, return the
1105	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
1106	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
1107	everything else.	1204	everything else.
1108		1205
1109	=cut	1206	=cut
1110		1207
…		…
1131	add $grp $dirgrp;	1228	add $grp $dirgrp;
1132	};	1229	};
1133		1230
1134	$grp	1231	$grp
1135	}	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.
1136		1252
1137	=item aio_sync $callback->($status)	1253	=item aio_sync $callback->($status)
1138		1254
1139	Asynchronously call sync and call the callback when finished.	1255	Asynchronously call sync and call the callback when finished.
1140		1256
…		…
1230		1346
1231	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
1232	scalars.	1348	scalars.
1233		1349
1234	It touches (reads or writes) all memory pages in the specified	1350	It touches (reads or writes) all memory pages in the specified
1235	range inside the scalar. All caveats and parameters are the same	1351	range inside the scalar. All caveats and parameters are the same
1236	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
1237	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
1238	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
1239	writing an octet from it, which dirties the page).	1355	writing an octet from it, which dirties the page).
1240		1356
1241	=item aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status)	1357	=item aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status)
1242		1358
1243	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
…		…
1277		1393
1278	aio_mlockall IO::AIO::MCL_FUTURE;	1394	aio_mlockall IO::AIO::MCL_FUTURE;
1279		1395
1280	=item aio_fiemap $fh, $start, $length, $flags, $count, $cb->(\@extents)	1396	=item aio_fiemap $fh, $start, $length, $flags, $count, $cb->(\@extents)
1281		1397
1282	Queries the extents of the given file (by calling the Linux FIEMAP ioctl,	1398	Queries the extents of the given file (by calling the Linux C<FIEMAP>
1283	see L<http://cvs.schmorp.de/IO-AIO/doc/fiemap.txt> for details). If the	1399	ioctl, see L<http://cvs.schmorp.de/IO-AIO/doc/fiemap.txt> for details). If
1284	C<ioctl> is not available on your OS, then this request will fail with	1400	the ioctl is not available on your OS, then this request will fail with
1285	C<ENOSYS>.	1401	C<ENOSYS>.
1286		1402
1287	C<$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<$length> is the
1288	size of the range to query - if it is C<undef>, then the whole file will	1404	size of the range to query - if it is C<undef>, then the whole file will
1289	be queried.	1405	be queried.
…		…
1292	C<IO::AIO::FIEMAP_FLAG_XATTR> - C<IO::AIO::FIEMAP_FLAGS_COMPAT> is also	1408	C<IO::AIO::FIEMAP_FLAG_XATTR> - C<IO::AIO::FIEMAP_FLAGS_COMPAT> is also
1293	exported), and is normally C<0> or C<IO::AIO::FIEMAP_FLAG_SYNC> to query	1409	exported), and is normally C<0> or C<IO::AIO::FIEMAP_FLAG_SYNC> to query
1294	the data portion.	1410	the data portion.
1295		1411
1296	C<$count> is the maximum number of extent records to return. If it is	1412	C<$count> is the maximum number of extent records to return. If it is
1297	C<undef>, then IO::AIO queries all extents of the file. As a very special	1413	C<undef>, then IO::AIO queries all extents of the range. As a very special
1298	case, if it is C<0>, then the callback receives the number of extents	1414	case, if it is C<0>, then the callback receives the number of extents
1299	instead of the extents themselves.	1415	instead of the extents themselves (which is unreliable, see below).
1300		1416
1301	If an error occurs, the callback receives no arguments. The special	1417	If an error occurs, the callback receives no arguments. The special
1302	C<errno> value C<IO::AIO::EBADR> is available to test for flag errors.	1418	C<errno> value C<IO::AIO::EBADR> is available to test for flag errors.
1303		1419
1304	Otherwise, the callback receives an array reference with extent	1420	Otherwise, the callback receives an array reference with extent
…		…
1306	following members:	1422	following members:
1307		1423
1308	[$logical, $physical, $length, $flags]	1424	[$logical, $physical, $length, $flags]
1309		1425
1310	Flags is any combination of the following flag values (typically either C<0>	1426	Flags is any combination of the following flag values (typically either C<0>
1311	or C<IO::AIO::FIEMAP_EXTENT_LAST>):	1427	or C<IO::AIO::FIEMAP_EXTENT_LAST> (1)):
1312		1428
1313	C<IO::AIO::FIEMAP_EXTENT_LAST>, C<IO::AIO::FIEMAP_EXTENT_UNKNOWN>,	1429	C<IO::AIO::FIEMAP_EXTENT_LAST>, C<IO::AIO::FIEMAP_EXTENT_UNKNOWN>,
1314	C<IO::AIO::FIEMAP_EXTENT_DELALLOC>, C<IO::AIO::FIEMAP_EXTENT_ENCODED>,	1430	C<IO::AIO::FIEMAP_EXTENT_DELALLOC>, C<IO::AIO::FIEMAP_EXTENT_ENCODED>,
1315	C<IO::AIO::FIEMAP_EXTENT_DATA_ENCRYPTED>, C<IO::AIO::FIEMAP_EXTENT_NOT_ALIGNED>,	1431	C<IO::AIO::FIEMAP_EXTENT_DATA_ENCRYPTED>, C<IO::AIO::FIEMAP_EXTENT_NOT_ALIGNED>,
1316	C<IO::AIO::FIEMAP_EXTENT_DATA_INLINE>, C<IO::AIO::FIEMAP_EXTENT_DATA_TAIL>,	1432	C<IO::AIO::FIEMAP_EXTENT_DATA_INLINE>, C<IO::AIO::FIEMAP_EXTENT_DATA_TAIL>,
1317	C<IO::AIO::FIEMAP_EXTENT_UNWRITTEN>, C<IO::AIO::FIEMAP_EXTENT_MERGED> or	1433	C<IO::AIO::FIEMAP_EXTENT_UNWRITTEN>, C<IO::AIO::FIEMAP_EXTENT_MERGED> or
1318	C<IO::AIO::FIEMAP_EXTENT_SHARED>.	1434	C<IO::AIO::FIEMAP_EXTENT_SHARED>.
1319		1435
		1436	At the time of this writing (Linux 3.2), this requets is unreliable unless
		1437	C<$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
1320	=item aio_group $callback->(...)	1441	=item aio_group $callback->(...)
1321		1442
1322	This is a very special aio request: Instead of doing something, it is a	1443	This is a very special aio request: Instead of doing something, it is a
1323	container for other aio requests, which is useful if you want to bundle	1444	container for other aio requests, which is useful if you want to bundle
1324	many requests into a single, composite, request with a definite callback	1445	many requests into a single, composite, request with a definite callback
…		…
1407	aio_stat [$etcdir, "passwd"], sub {	1528	aio_stat [$etcdir, "passwd"], sub {
1408	# yay	1529	# yay
1409	};	1530	};
1410	};	1531	};
1411		1532
1412	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
1413	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,
1414	why it is done asynchronously.	1535	which is why it is done asynchronously.
1415		1536
1416	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
1417	either of the following three request calls:	1538	either of the following three request calls:
1418		1539
1419	aio_lstat "/etc" , sub { ... # pathname as normal string	1540	aio_lstat "/etc" , sub { ... # pathname as normal string
…		…
1439	will still point to the original directory. Most functions accepting a	1560	will still point to the original directory. Most functions accepting a
1440	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
1441	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
1442	string form of the pathname.	1563	string form of the pathname.
1443		1564
1444	So this fucntionality is mainly useful to get some protection against	1565	So this functionality is mainly useful to get some protection against
1445	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
1446	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
1447	(e.g. when stat'ing all files in a directory).	1568	(e.g. when stat'ing all files in a directory).
1448		1569
1449	The following functions implement this working directory abstraction:	1570	The following functions implement this working directory abstraction:
…		…
1462	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
1463	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
1464	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
1465	expected way.	1586	expected way.
1466		1587
1467	If this call isn't available because your OS lacks it or it couldn't be
1468	detected, it will be emulated by calling C<fsync> instead.
1469
1470	=item IO::AIO::CWD	1588	=item IO::AIO::CWD
1471		1589
1472	This is a compiletime constant (object) that represents the process	1590	This is a compiletime constant (object) that represents the process
1473	current working directory.	1591	current working directory.
1474		1592
1475	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
1476	if the pathname would be specified directly, without a directory object,	1594	the pathname would be specified directly, without a directory object. For
1477	e.g., these calls are functionally identical:	1595	example, these calls are functionally identical:
1478		1596
1479	aio_stat "somefile", sub { ... };	1597	aio_stat "somefile", sub { ... };
1480	aio_stat [IO::AIO::CWD, "somefile"], sub { ... };	1598	aio_stat [IO::AIO::CWD, "somefile"], sub { ... };
1481		1599
1482	=back	1600	=back
1483		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.
1484		1611
1485	=head2 IO::AIO::REQ CLASS	1612	=head2 IO::AIO::REQ CLASS
1486		1613
1487	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
1488	called in non-void context.	1615	called in non-void context.
…		…
1666		1793
1667	See C<poll_cb> for an example.	1794	See C<poll_cb> for an example.
1668		1795
1669	=item IO::AIO::poll_cb	1796	=item IO::AIO::poll_cb
1670		1797
1671	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
1672	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
1673	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
1674	reason. Returns immediately when no events are outstanding. The amount of	1804	reason. Returns immediately when no events are outstanding. The amount
1675	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>,
1676	C<IO::AIO::max_poll_time>.	1806	C<IO::AIO::max_poll_time> and C<IO::AIO::max_outstanding>.
1677		1807
1678	If not all requests were processed for whatever reason, the filehandle	1808	If not all requests were processed for whatever reason, the poll file
1679	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
1680	do anything special to have it called later.	1810	don't have to do anything special to have it called later.
1681		1811
1682	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
1683	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
1684	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
1685	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
…		…
1694	poll => 'r', async => 1,	1824	poll => 'r', async => 1,
1695	cb => \&IO::AIO::poll_cb);	1825	cb => \&IO::AIO::poll_cb);
1696		1826
1697	=item IO::AIO::poll_wait	1827	=item IO::AIO::poll_wait
1698		1828
1699	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
1700	phase, wait till the result filehandle becomes ready for reading (simply	1830	requests are outstanding anymore.
1701	does a C<select> on the filehandle. This is useful if you want to	1831
1702	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.
1703		1834
1704	See C<nreqs> for an example.	1835	See C<nreqs> for an example.
1705		1836
1706	=item IO::AIO::poll	1837	=item IO::AIO::poll
1707		1838
…		…
1828		1959
1829	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
1830	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
1831	use an C<aio_group> together with a feed callback.	1962	use an C<aio_group> together with a feed callback.
1832		1963
1833	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
1834	a lot of files, you can write somehting like this:	1965	a lot of files, you can write somehting like this:
1835		1966
1836	IO::AIO::max_outstanding 32;	1967	IO::AIO::max_outstanding 32;
1837		1968
1838	for my $path (...) {	1969	for my $path (...) {
…		…
1878		2009
1879	=back	2010	=back
1880		2011
1881	=head3 MISCELLANEOUS FUNCTIONS	2012	=head3 MISCELLANEOUS FUNCTIONS
1882		2013
1883	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
1884	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.
1885		2018
1886	=over 4	2019	=over 4
1887		2020
1888	=item IO::AIO::sendfile $ofh, $ifh, $offset, $count	2021	=item IO::AIO::sendfile $ofh, $ifh, $offset, $count
1889		2022
…		…
1948	filesize.	2081	filesize.
1949		2082
1950	C<$prot> is a combination of C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_EXEC>,	2083	C<$prot> is a combination of C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_EXEC>,
1951	C<IO::AIO::PROT_READ> and/or C<IO::AIO::PROT_WRITE>,	2084	C<IO::AIO::PROT_READ> and/or C<IO::AIO::PROT_WRITE>,
1952		2085
1953	C<$flags> can be a combination of C<IO::AIO::MAP_SHARED> or	2086	C<$flags> can be a combination of
1954	C<IO::AIO::MAP_PRIVATE>, or a number of system-specific flags (when	2087	C<IO::AIO::MAP_SHARED> or
1955	not available, the are defined as 0): C<IO::AIO::MAP_ANONYMOUS>	2088	C<IO::AIO::MAP_PRIVATE>,
		2089	or a number of system-specific flags (when not available, the are C<0>):
1956	(which is set to C<MAP_ANON> if your system only provides this	2090	C<IO::AIO::MAP_ANONYMOUS> (which is set to C<MAP_ANON> if your system only provides this constant),
1957	constant), C<IO::AIO::MAP_HUGETLB>, C<IO::AIO::MAP_LOCKED>,	2091	C<IO::AIO::MAP_LOCKED>,
1958	C<IO::AIO::MAP_NORESERVE>, C<IO::AIO::MAP_POPULATE> or	2092	C<IO::AIO::MAP_NORESERVE>,
		2093	C<IO::AIO::MAP_POPULATE>,
1959	C<IO::AIO::MAP_NONBLOCK>	2094	C<IO::AIO::MAP_NONBLOCK>,
		2095	C<IO::AIO::MAP_FIXED>,
		2096	C<IO::AIO::MAP_GROWSDOWN>,
		2097	C<IO::AIO::MAP_32BIT>,
		2098	C<IO::AIO::MAP_HUGETLB> or
		2099	C<IO::AIO::MAP_STACK>.
1960		2100
1961	If C<$fh> is C<undef>, then a file descriptor of C<-1> is passed.	2101	If C<$fh> is C<undef>, then a file descriptor of C<-1> is passed.
1962		2102
1963	C<$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
1964	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>.
…		…
2007		2147
2008	See the C<splice(2)> manpage for details.	2148	See the C<splice(2)> manpage for details.
2009		2149
2010	=item IO::AIO::tee $r_fh, $w_fh, $length, $flags	2150	=item IO::AIO::tee $r_fh, $w_fh, $length, $flags
2011		2151
2012	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
2013	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.
2014		2181
2015	=back	2182	=back
2016		2183
2017	=cut	2184	=cut
2018		2185

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Comparing IO-AIO/AIO.pm (file contents): Revision 1.230 by root, Fri Jul 27 17:24:06 2012 UTC vs. Revision 1.259 by root, Tue Feb 23 19:42:43 2016 UTC

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Comparing IO-AIO/AIO.pm (file contents):
Revision 1.230 by root, Fri Jul 27 17:24:06 2012 UTC vs.
Revision 1.259 by root, Tue Feb 23 19:42:43 2016 UTC