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

Comparing IO-AIO/AIO.pm (file contents):
Revision 1.235 by root, Wed Aug 22 22:28:03 2012 UTC vs.
Revision 1.267 by root, Tue Aug 9 11:39:17 2016 UTC

…		…
1	=head1 NAME	1	=head1 NAME
2		2
3	IO::AIO - Asynchronous Input/Output	3	IO::AIO - Asynchronous/Advanced Input/Output
4		4
5	=head1 SYNOPSIS	5	=head1 SYNOPSIS
6		6
7	use IO::AIO;	7	use IO::AIO;
8		8
58	not well-supported or restricted (GNU/Linux doesn't allow them on normal	58	not well-supported or restricted (GNU/Linux doesn't allow them on normal
59	files currently, for example), and they would only support aio_read and	59	files currently, for example), and they would only support aio_read and
60	aio_write, so the remaining functionality would have to be implemented	60	aio_write, so the remaining functionality would have to be implemented
61	using threads anyway.	61	using threads anyway.
62		62
		63	In addition to asynchronous I/O, this module also exports some rather
		64	arcane interfaces, such as C<madvise> or linux's C<splice> system call,
		65	which is why the C<A> in C<AIO> can also mean I<advanced>.
		66
63	Although the module will work in the presence of other (Perl-) threads,	67	Although the module will work in the presence of other (Perl-) threads,
64	it is currently not reentrant in any way, so use appropriate locking	68	it is currently not reentrant in any way, so use appropriate locking
65	yourself, always call C<poll_cb> from within the same thread, or never	69	yourself, always call C<poll_cb> from within the same thread, or never
66	call C<poll_cb> (or other C<aio_> functions) recursively.	70	call C<poll_cb> (or other C<aio_> functions) recursively.
67		71
68	=head2 EXAMPLE	72	=head2 EXAMPLE
69		73
70	This is a simple example that uses the EV module and loads	74	This is a simple example that uses the EV module and loads
71	F</etc/passwd> asynchronously:	75	F</etc/passwd> asynchronously:
72		76
73	use Fcntl;
74	use EV;	77	use EV;
75	use IO::AIO;	78	use IO::AIO;
76		79
77	# register the IO::AIO callback with EV	80	# register the IO::AIO callback with EV
78	my $aio_w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb;	81	my $aio_w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb;
…		…
95		98
96	# file contents now in $contents	99	# file contents now in $contents
97	print $contents;	100	print $contents;
98		101
99	# exit event loop and program	102	# exit event loop and program
100	EV::unloop;	103	EV::break;
101	};	104	};
102	};	105	};
103		106
104	# possibly queue up other requests, or open GUI windows,	107	# possibly queue up other requests, or open GUI windows,
105	# check for sockets etc. etc.	108	# check for sockets etc. etc.
106		109
107	# process events as long as there are some:	110	# process events as long as there are some:
108	EV::loop;	111	EV::run;
109		112
110	=head1 REQUEST ANATOMY AND LIFETIME	113	=head1 REQUEST ANATOMY AND LIFETIME
111		114
112	Every C<aio_*> function creates a request. which is a C data structure not	115	Every C<aio_*> function creates a request. which is a C data structure not
113	directly visible to Perl.	116	directly visible to Perl.
…		…
168	use common::sense;	171	use common::sense;
169		172
170	use base 'Exporter';	173	use base 'Exporter';
171		174
172	BEGIN {	175	BEGIN {
173	our $VERSION = '4.16';	176	our $VERSION = 4.34;
174		177
175	our @AIO_REQ = qw(aio_sendfile aio_seek aio_read aio_write aio_open aio_close	178	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	179	aio_stat aio_lstat aio_unlink aio_rmdir aio_readdir aio_readdirx
177	aio_scandir aio_symlink aio_readlink aio_realpath aio_sync	180	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	181	aio_sync aio_fsync aio_syncfs aio_fdatasync aio_sync_file_range
179	aio_pathsync aio_readahead aio_fiemap	182	aio_pathsync aio_readahead aio_fiemap aio_allocate
180	aio_rename aio_link aio_move aio_copy aio_group	183	aio_rename aio_link aio_move aio_copy aio_group
181	aio_nop aio_mknod aio_load aio_rmtree aio_mkdir aio_chown	184	aio_nop aio_mknod aio_load aio_rmtree aio_mkdir aio_chown
182	aio_chmod aio_utime aio_truncate	185	aio_chmod aio_utime aio_truncate
183	aio_msync aio_mtouch aio_mlock aio_mlockall	186	aio_msync aio_mtouch aio_mlock aio_mlockall
184	aio_statvfs	187	aio_statvfs
…		…
228	aio_unlink $pathname, $callback->($status)	231	aio_unlink $pathname, $callback->($status)
229	aio_mknod $pathname, $mode, $dev, $callback->($status)	232	aio_mknod $pathname, $mode, $dev, $callback->($status)
230	aio_link $srcpath, $dstpath, $callback->($status)	233	aio_link $srcpath, $dstpath, $callback->($status)
231	aio_symlink $srcpath, $dstpath, $callback->($status)	234	aio_symlink $srcpath, $dstpath, $callback->($status)
232	aio_readlink $pathname, $callback->($link)	235	aio_readlink $pathname, $callback->($link)
233	aio_realpath $pathname, $callback->($link)	236	aio_realpath $pathname, $callback->($path)
234	aio_rename $srcpath, $dstpath, $callback->($status)	237	aio_rename $srcpath, $dstpath, $callback->($status)
235	aio_mkdir $pathname, $mode, $callback->($status)	238	aio_mkdir $pathname, $mode, $callback->($status)
236	aio_rmdir $pathname, $callback->($status)	239	aio_rmdir $pathname, $callback->($status)
237	aio_readdir $pathname, $callback->($entries)	240	aio_readdir $pathname, $callback->($entries)
238	aio_readdirx $pathname, $flags, $callback->($entries, $flags)	241	aio_readdirx $pathname, $flags, $callback->($entries, $flags)
…		…
241	aio_scandir $pathname, $maxreq, $callback->($dirs, $nondirs)	244	aio_scandir $pathname, $maxreq, $callback->($dirs, $nondirs)
242	aio_load $pathname, $data, $callback->($status)	245	aio_load $pathname, $data, $callback->($status)
243	aio_copy $srcpath, $dstpath, $callback->($status)	246	aio_copy $srcpath, $dstpath, $callback->($status)
244	aio_move $srcpath, $dstpath, $callback->($status)	247	aio_move $srcpath, $dstpath, $callback->($status)
245	aio_rmtree $pathname, $callback->($status)	248	aio_rmtree $pathname, $callback->($status)
		249	aio_fcntl $fh, $cmd, $arg, $callback->($status)
		250	aio_ioctl $fh, $request, $buf, $callback->($status)
246	aio_sync $callback->($status)	251	aio_sync $callback->($status)
247	aio_syncfs $fh, $callback->($status)	252	aio_syncfs $fh, $callback->($status)
248	aio_fsync $fh, $callback->($status)	253	aio_fsync $fh, $callback->($status)
249	aio_fdatasync $fh, $callback->($status)	254	aio_fdatasync $fh, $callback->($status)
250	aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status)	255	aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status)
…		…
395	following POSIX and non-POSIX constants are available (missing ones on	400	following POSIX and non-POSIX constants are available (missing ones on
396	your system are, as usual, C<0>):	401	your system are, as usual, C<0>):
397		402
398	C<O_ASYNC>, C<O_DIRECT>, C<O_NOATIME>, C<O_CLOEXEC>, C<O_NOCTTY>, C<O_NOFOLLOW>,	403	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>,	404	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>.	405	C<O_RSYNC>, C<O_SYNC>, C<O_PATH>, C<O_TMPFILE>, and C<O_TTY_INIT>.
401		406
402		407
403	=item aio_close $fh, $callback->($status)	408	=item aio_close $fh, $callback->($status)
404		409
405	Asynchronously close a file and call the callback with the result	410	Asynchronously close a file and call the callback with the result
…		…
440	=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)	445	=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
441		446
442	=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)	447	=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
443		448
444	Reads or writes C<$length> bytes from or to the specified C<$fh> and	449	Reads or writes C<$length> bytes from or to the specified C<$fh> and
445	C<$offset> into the scalar given by C<$data> and offset C<$dataoffset>	450	C<$offset> into the scalar given by C<$data> and offset C<$dataoffset> and
446	and calls the callback without the actual number of bytes read (or -1 on	451	calls the callback with the actual number of bytes transferred (or -1 on
447	error, just like the syscall).	452	error, just like the syscall).
448		453
449	C<aio_read> will, like C<sysread>, shrink or grow the C<$data> scalar to	454	C<aio_read> will, like C<sysread>, shrink or grow the C<$data> scalar to
450	offset plus the actual number of bytes read.	455	offset plus the actual number of bytes read.
451		456
…		…
509	As native sendfile syscalls (as practically any non-POSIX interface hacked	514	As native sendfile syscalls (as practically any non-POSIX interface hacked
510	together in a hurry to improve benchmark numbers) tend to be rather buggy	515	together in a hurry to improve benchmark numbers) tend to be rather buggy
511	on many systems, this implementation tries to work around some known bugs	516	on many systems, this implementation tries to work around some known bugs
512	in Linux and FreeBSD kernels (probably others, too), but that might fail,	517	in Linux and FreeBSD kernels (probably others, too), but that might fail,
513	so you really really should check the return value of C<aio_sendfile> -	518	so you really really should check the return value of C<aio_sendfile> -
514	fewre bytes than expected might have been transferred.	519	fewer bytes than expected might have been transferred.
515		520
516		521
517	=item aio_readahead $fh,$offset,$length, $callback->($retval)	522	=item aio_readahead $fh,$offset,$length, $callback->($retval)
518		523
519	C<aio_readahead> populates the page cache with data from a file so that	524	C<aio_readahead> populates the page cache with data from a file so that
…		…
523	whole pages, so that offset is effectively rounded down to a page boundary	528	whole pages, so that offset is effectively rounded down to a page boundary
524	and bytes are read up to the next page boundary greater than or equal to	529	and bytes are read up to the next page boundary greater than or equal to
525	(off-set+length). C<aio_readahead> does not read beyond the end of the	530	(off-set+length). C<aio_readahead> does not read beyond the end of the
526	file. The current file offset of the file is left unchanged.	531	file. The current file offset of the file is left unchanged.
527		532
528	If that syscall doesn't exist (likely if your OS isn't Linux) it will be	533	If that syscall doesn't exist (likely if your kernel isn't Linux) it will
529	emulated by simply reading the data, which would have a similar effect.	534	be emulated by simply reading the data, which would have a similar effect.
530		535
531		536
532	=item aio_stat $fh_or_path, $callback->($status)	537	=item aio_stat $fh_or_path, $callback->($status)
533		538
534	=item aio_lstat $fh, $callback->($status)	539	=item aio_lstat $fh, $callback->($status)
…		…
603	namemax => 255,	608	namemax => 255,
604	frsize => 1024,	609	frsize => 1024,
605	fsid => 1810	610	fsid => 1810
606	}	611	}
607		612
608	Here is a (likely partial) list of fsid values used by Linux - it is safe	613	Here is a (likely partial - send me updates!) list of fsid values used by
609	to hardcode these when the $^O is C<linux>:	614	Linux - it is safe to hardcode these when C<$^O> is C<linux>:
610		615
611	0x0000adf5 adfs	616	0x0000adf5 adfs
612	0x0000adff affs	617	0x0000adff affs
613	0x5346414f afs	618	0x5346414f afs
614	0x09041934 anon-inode filesystem	619	0x09041934 anon-inode filesystem
…		…
627	0x00001373 devfs	632	0x00001373 devfs
628	0x00001cd1 devpts	633	0x00001cd1 devpts
629	0x0000f15f ecryptfs	634	0x0000f15f ecryptfs
630	0x00414a53 efs	635	0x00414a53 efs
631	0x0000137d ext	636	0x0000137d ext
632	0x0000ef53 ext2/ext3	637	0x0000ef53 ext2/ext3/ext4
633	0x0000ef51 ext2	638	0x0000ef51 ext2
		639	0xf2f52010 f2fs
634	0x00004006 fat	640	0x00004006 fat
635	0x65735546 fuseblk	641	0x65735546 fuseblk
636	0x65735543 fusectl	642	0x65735543 fusectl
637	0x0bad1dea futexfs	643	0x0bad1dea futexfs
638	0x01161970 gfs2	644	0x01161970 gfs2
639	0x47504653 gpfs	645	0x47504653 gpfs
640	0x00004244 hfs	646	0x00004244 hfs
641	0xf995e849 hpfs	647	0xf995e849 hpfs
		648	0x00c0ffee hostfs
642	0x958458f6 hugetlbfs	649	0x958458f6 hugetlbfs
643	0x2bad1dea inotifyfs	650	0x2bad1dea inotifyfs
644	0x00009660 isofs	651	0x00009660 isofs
645	0x000072b6 jffs2	652	0x000072b6 jffs2
646	0x3153464a jfs	653	0x3153464a jfs
…		…
661	0x00009fa1 openprom	668	0x00009fa1 openprom
662	0x7461636F ocfs2	669	0x7461636F ocfs2
663	0x00009fa0 proc	670	0x00009fa0 proc
664	0x6165676c pstorefs	671	0x6165676c pstorefs
665	0x0000002f qnx4	672	0x0000002f qnx4
		673	0x68191122 qnx6
666	0x858458f6 ramfs	674	0x858458f6 ramfs
667	0x52654973 reiserfs	675	0x52654973 reiserfs
668	0x00007275 romfs	676	0x00007275 romfs
669	0x67596969 rpc_pipefs	677	0x67596969 rpc_pipefs
670	0x73636673 securityfs	678	0x73636673 securityfs
…		…
723	Works like truncate(2) or ftruncate(2).	731	Works like truncate(2) or ftruncate(2).
724		732
725		733
726	=item aio_allocate $fh, $mode, $offset, $len, $callback->($status)	734	=item aio_allocate $fh, $mode, $offset, $len, $callback->($status)
727		735
728	Allocates or freed disk space according to the C<$mode> argument. See the	736	Allocates or frees disk space according to the C<$mode> argument. See the
729	linux C<fallocate> docuemntation for details.	737	linux C<fallocate> documentation for details.
730		738
731	C<$mode> can currently be C<0> or C<IO::AIO::FALLOC_FL_KEEP_SIZE>	739	C<$mode> is usually C<0> or C<IO::AIO::FALLOC_FL_KEEP_SIZE> to allocate
732	to allocate space, or C<IO::AIO::FALLOC_FL_PUNCH_HOLE \|	740	space, or C<IO::AIO::FALLOC_FL_PUNCH_HOLE \| IO::AIO::FALLOC_FL_KEEP_SIZE>,
733	IO::AIO::FALLOC_FL_KEEP_SIZE>, to deallocate a file range.	741	to deallocate a file range.
		742
		743	IO::AIO also supports C<FALLOC_FL_COLLAPSE_RANGE>, to remove a range
		744	(without leaving a hole) and C<FALLOC_FL_ZERO_RANGE>, to zero a range (see
		745	your L<fallocate(2)> manpage).
734		746
735	The file system block size used by C<fallocate> is presumably the	747	The file system block size used by C<fallocate> is presumably the
736	C<f_bsize> returned by C<statvfs>.	748	C<f_bsize> returned by C<statvfs>.
737		749
738	If C<fallocate> isn't available or cannot be emulated (currently no	750	If C<fallocate> isn't available or cannot be emulated (currently no
…		…
783		795
784		796
785	=item aio_realpath $pathname, $callback->($path)	797	=item aio_realpath $pathname, $callback->($path)
786		798
787	Asynchronously make the path absolute and resolve any symlinks in	799	Asynchronously make the path absolute and resolve any symlinks in
788	C<$path>. The resulting path only consists of directories (Same as	800	C<$path>. The resulting path only consists of directories (same as
789	L<Cwd::realpath>).	801	L<Cwd::realpath>).
790		802
791	This request can be used to get the absolute path of the current working	803	This request can be used to get the absolute path of the current working
792	directory by passing it a path of F<.> (a single dot).	804	directory by passing it a path of F<.> (a single dot).
793		805
794		806
795	=item aio_rename $srcpath, $dstpath, $callback->($status)	807	=item aio_rename $srcpath, $dstpath, $callback->($status)
796		808
797	Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as	809	Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as
798	rename(2) and call the callback with the result code.	810	rename(2) and call the callback with the result code.
		811
		812	On systems that support the AIO::WD working directory abstraction
		813	natively, the case C<[$wd, "."]> as C<$srcpath> is specialcased - instead
		814	of failing, C<rename> is called on the absolute path of C<$wd>.
799		815
800		816
801	=item aio_mkdir $pathname, $mode, $callback->($status)	817	=item aio_mkdir $pathname, $mode, $callback->($status)
802		818
803	Asynchronously mkdir (create) a directory and call the callback with	819	Asynchronously mkdir (create) a directory and call the callback with
…		…
807		823
808	=item aio_rmdir $pathname, $callback->($status)	824	=item aio_rmdir $pathname, $callback->($status)
809		825
810	Asynchronously rmdir (delete) a directory and call the callback with the	826	Asynchronously rmdir (delete) a directory and call the callback with the
811	result code.	827	result code.
		828
		829	On systems that support the AIO::WD working directory abstraction
		830	natively, the case C<[$wd, "."]> is specialcased - instead of failing,
		831	C<rmdir> is called on the absolute path of C<$wd>.
812		832
813		833
814	=item aio_readdir $pathname, $callback->($entries)	834	=item aio_readdir $pathname, $callback->($entries)
815		835
816	Unlike the POSIX call of the same name, C<aio_readdir> reads an entire	836	Unlike the POSIX call of the same name, C<aio_readdir> reads an entire
…		…
1181	}	1201	}
1182		1202
1183	=item aio_rmtree $pathname, $callback->($status)	1203	=item aio_rmtree $pathname, $callback->($status)
1184		1204
1185	Delete a directory tree starting (and including) C<$path>, return the	1205	Delete a directory tree starting (and including) C<$path>, return the
1186	status of the final C<rmdir> only. This is a composite request that	1206	status of the final C<rmdir> only. This is a composite request that
1187	uses C<aio_scandir> to recurse into and rmdir directories, and unlink	1207	uses C<aio_scandir> to recurse into and rmdir directories, and unlink
1188	everything else.	1208	everything else.
1189		1209
1190	=cut	1210	=cut
1191		1211
…		…
1212	add $grp $dirgrp;	1232	add $grp $dirgrp;
1213	};	1233	};
1214		1234
1215	$grp	1235	$grp
1216	}	1236	}
		1237
		1238	=item aio_fcntl $fh, $cmd, $arg, $callback->($status)
		1239
		1240	=item aio_ioctl $fh, $request, $buf, $callback->($status)
		1241
		1242	These work just like the C<fcntl> and C<ioctl> built-in functions, except
		1243	they execute asynchronously and pass the return value to the callback.
		1244
		1245	Both calls can be used for a lot of things, some of which make more sense
		1246	to run asynchronously in their own thread, while some others make less
		1247	sense. For example, calls that block waiting for external events, such
		1248	as locking, will also lock down an I/O thread while it is waiting, which
		1249	can deadlock the whole I/O system. At the same time, there might be no
		1250	alternative to using a thread to wait.
		1251
		1252	So in general, you should only use these calls for things that do
		1253	(filesystem) I/O, not for things that wait for other events (network,
		1254	other processes), although if you are careful and know what you are doing,
		1255	you still can.
		1256
		1257	The following constants are available (missing ones are, as usual C<0>):
		1258
		1259	C<FIFREEZE>, C<FITHAW>, C<FITRIM>, C<FICLONE>, C<FICLONERANGE>, C<FIDEDUPERANGE>.
		1260
		1261	C<FS_IOC_GETFLAGS>, C<FS_IOC_SETFLAGS>, C<FS_IOC_GETVERSION>, C<FS_IOC_SETVERSION>,
		1262	C<FS_IOC_FIEMAP>.
		1263
		1264	C<FS_IOC_FSGETXATTR>, C<FS_IOC_FSSETXATTR>, C<FS_IOC_SET_ENCRYPTION_POLICY>,
		1265	C<FS_IOC_GET_ENCRYPTION_PWSALT>, C<FS_IOC_GET_ENCRYPTION_POLICY>, C<FS_KEY_DESCRIPTOR_SIZE>.
		1266
		1267	C<FS_SECRM_FL>, C<FS_UNRM_FL>, C<FS_COMPR_FL>, C<FS_SYNC_FL>, C<FS_IMMUTABLE_FL>,
		1268	C<FS_APPEND_FL>, C<FS_NODUMP_FL>, C<FS_NOATIME_FL>, C<FS_DIRTY_FL>,
		1269	C<FS_COMPRBLK_FL>, C<FS_NOCOMP_FL>, C<FS_ENCRYPT_FL>, C<FS_BTREE_FL>,
		1270	C<FS_INDEX_FL>, C<FS_JOURNAL_DATA_FL>, C<FS_NOTAIL_FL>, C<FS_DIRSYNC_FL>, C<FS_TOPDIR_FL>,
		1271	C<FS_FL_USER_MODIFIABLE>.
		1272
		1273	C<FS_XFLAG_REALTIME>, C<FS_XFLAG_PREALLOC>, C<FS_XFLAG_IMMUTABLE>, C<FS_XFLAG_APPEND>,
		1274	C<FS_XFLAG_SYNC>, C<FS_XFLAG_NOATIME>, C<FS_XFLAG_NODUMP>, C<FS_XFLAG_RTINHERIT>,
		1275	C<FS_XFLAG_PROJINHERIT>, C<FS_XFLAG_NOSYMLINKS>, C<FS_XFLAG_EXTSIZE>, C<FS_XFLAG_EXTSZINHERIT>,
		1276	C<FS_XFLAG_NODEFRAG>, C<FS_XFLAG_FILESTREAM>, C<FS_XFLAG_DAX>, C<FS_XFLAG_HASATTR>,
1217		1277
1218	=item aio_sync $callback->($status)	1278	=item aio_sync $callback->($status)
1219		1279
1220	Asynchronously call sync and call the callback when finished.	1280	Asynchronously call sync and call the callback when finished.
1221		1281
…		…
1311		1371
1312	This is a rather advanced IO::AIO call, which works best on mmap(2)ed	1372	This is a rather advanced IO::AIO call, which works best on mmap(2)ed
1313	scalars.	1373	scalars.
1314		1374
1315	It touches (reads or writes) all memory pages in the specified	1375	It touches (reads or writes) all memory pages in the specified
1316	range inside the scalar. All caveats and parameters are the same	1376	range inside the scalar. All caveats and parameters are the same
1317	as for C<aio_msync>, above, except for flags, which must be either	1377	as for C<aio_msync>, above, except for flags, which must be either
1318	C<0> (which reads all pages and ensures they are instantiated) or	1378	C<0> (which reads all pages and ensures they are instantiated) or
1319	C<IO::AIO::MT_MODIFY>, which modifies the memory page s(by reading and	1379	C<IO::AIO::MT_MODIFY>, which modifies the memory pages (by reading and
1320	writing an octet from it, which dirties the page).	1380	writing an octet from it, which dirties the page).
1321		1381
1322	=item aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status)	1382	=item aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status)
1323		1383
1324	This is a rather advanced IO::AIO call, which works best on mmap(2)ed	1384	This is a rather advanced IO::AIO call, which works best on mmap(2)ed
…		…
1493	aio_stat [$etcdir, "passwd"], sub {	1553	aio_stat [$etcdir, "passwd"], sub {
1494	# yay	1554	# yay
1495	};	1555	};
1496	};	1556	};
1497		1557
1498	That C<aio_wd> is a request and not a normal function shows that creating	1558	The fact that C<aio_wd> is a request and not a normal function shows that
1499	an IO::AIO::WD object is itself a potentially blocking operation, which is	1559	creating an IO::AIO::WD object is itself a potentially blocking operation,
1500	why it is done asynchronously.	1560	which is why it is done asynchronously.
1501		1561
1502	To stat the directory obtained with C<aio_wd> above, one could write	1562	To stat the directory obtained with C<aio_wd> above, one could write
1503	either of the following three request calls:	1563	either of the following three request calls:
1504		1564
1505	aio_lstat "/etc" , sub { ... # pathname as normal string	1565	aio_lstat "/etc" , sub { ... # pathname as normal string
…		…
1525	will still point to the original directory. Most functions accepting a	1585	will still point to the original directory. Most functions accepting a
1526	pathname will use the directory fd on newer systems, and the string on	1586	pathname will use the directory fd on newer systems, and the string on
1527	older systems. Some functions (such as realpath) will always rely on the	1587	older systems. Some functions (such as realpath) will always rely on the
1528	string form of the pathname.	1588	string form of the pathname.
1529		1589
1530	So this fucntionality is mainly useful to get some protection against	1590	So this functionality is mainly useful to get some protection against
1531	C<chdir>, to easily get an absolute path out of a relative path for future	1591	C<chdir>, to easily get an absolute path out of a relative path for future
1532	reference, and to speed up doing many operations in the same directory	1592	reference, and to speed up doing many operations in the same directory
1533	(e.g. when stat'ing all files in a directory).	1593	(e.g. when stat'ing all files in a directory).
1534		1594
1535	The following functions implement this working directory abstraction:	1595	The following functions implement this working directory abstraction:
…		…
1548	passing C<undef> as working directory component of a pathname fails the	1608	passing C<undef> as working directory component of a pathname fails the
1549	request with C<ENOENT>, there is often no need for error checking in the	1609	request with C<ENOENT>, there is often no need for error checking in the
1550	C<aio_wd> callback, as future requests using the value will fail in the	1610	C<aio_wd> callback, as future requests using the value will fail in the
1551	expected way.	1611	expected way.
1552		1612
1553	If this call isn't available because your OS lacks it or it couldn't be
1554	detected, it will be emulated by calling C<fsync> instead.
1555
1556	=item IO::AIO::CWD	1613	=item IO::AIO::CWD
1557		1614
1558	This is a compiletime constant (object) that represents the process	1615	This is a compiletime constant (object) that represents the process
1559	current working directory.	1616	current working directory.
1560		1617
1561	Specifying this object as working directory object for a pathname is as	1618	Specifying this object as working directory object for a pathname is as if
1562	if the pathname would be specified directly, without a directory object,	1619	the pathname would be specified directly, without a directory object. For
1563	e.g., these calls are functionally identical:	1620	example, these calls are functionally identical:
1564		1621
1565	aio_stat "somefile", sub { ... };	1622	aio_stat "somefile", sub { ... };
1566	aio_stat [IO::AIO::CWD, "somefile"], sub { ... };	1623	aio_stat [IO::AIO::CWD, "somefile"], sub { ... };
1567		1624
1568	=back	1625	=back
1569		1626
		1627	To recover the path associated with an IO::AIO::WD object, you can use
		1628	C<aio_realpath>:
		1629
		1630	aio_realpath $wd, sub {
		1631	warn "path is $_[0]\n";
		1632	};
		1633
		1634	Currently, C<aio_statvfs> always, and C<aio_rename> and C<aio_rmdir>
		1635	sometimes, fall back to using an absolue path.
1570		1636
1571	=head2 IO::AIO::REQ CLASS	1637	=head2 IO::AIO::REQ CLASS
1572		1638
1573	All non-aggregate C<aio_*> functions return an object of this class when	1639	All non-aggregate C<aio_*> functions return an object of this class when
1574	called in non-void context.	1640	called in non-void context.
…		…
1752		1818
1753	See C<poll_cb> for an example.	1819	See C<poll_cb> for an example.
1754		1820
1755	=item IO::AIO::poll_cb	1821	=item IO::AIO::poll_cb
1756		1822
1757	Process some outstanding events on the result pipe. You have to call	1823	Process some requests that have reached the result phase (i.e. they have
		1824	been executed but the results are not yet reported). You have to call
		1825	this "regularly" to finish outstanding requests.
		1826
1758	this regularly. Returns C<0> if all events could be processed (or there	1827	Returns C<0> if all events could be processed (or there were no
1759	were no events to process), or C<-1> if it returned earlier for whatever	1828	events to process), or C<-1> if it returned earlier for whatever
1760	reason. Returns immediately when no events are outstanding. The amount of	1829	reason. Returns immediately when no events are outstanding. The amount
1761	events processed depends on the settings of C<IO::AIO::max_poll_req> and	1830	of events processed depends on the settings of C<IO::AIO::max_poll_req>,
1762	C<IO::AIO::max_poll_time>.	1831	C<IO::AIO::max_poll_time> and C<IO::AIO::max_outstanding>.
1763		1832
1764	If not all requests were processed for whatever reason, the filehandle	1833	If not all requests were processed for whatever reason, the poll file
1765	will still be ready when C<poll_cb> returns, so normally you don't have to	1834	descriptor will still be ready when C<poll_cb> returns, so normally you
1766	do anything special to have it called later.	1835	don't have to do anything special to have it called later.
1767		1836
1768	Apart from calling C<IO::AIO::poll_cb> when the event filehandle becomes	1837	Apart from calling C<IO::AIO::poll_cb> when the event filehandle becomes
1769	ready, it can be beneficial to call this function from loops which submit	1838	ready, it can be beneficial to call this function from loops which submit
1770	a lot of requests, to make sure the results get processed when they become	1839	a lot of requests, to make sure the results get processed when they become
1771	available and not just when the loop is finished and the event loop takes	1840	available and not just when the loop is finished and the event loop takes
…		…
1780	poll => 'r', async => 1,	1849	poll => 'r', async => 1,
1781	cb => \&IO::AIO::poll_cb);	1850	cb => \&IO::AIO::poll_cb);
1782		1851
1783	=item IO::AIO::poll_wait	1852	=item IO::AIO::poll_wait
1784		1853
1785	If there are any outstanding requests and none of them in the result	1854	Wait until either at least one request is in the result phase or no
1786	phase, wait till the result filehandle becomes ready for reading (simply	1855	requests are outstanding anymore.
1787	does a C<select> on the filehandle. This is useful if you want to	1856
1788	synchronously wait for some requests to finish).	1857	This is useful if you want to synchronously wait for some requests to
		1858	become ready, without actually handling them.
1789		1859
1790	See C<nreqs> for an example.	1860	See C<nreqs> for an example.
1791		1861
1792	=item IO::AIO::poll	1862	=item IO::AIO::poll
1793		1863
…		…
1914		1984
1915	This is a very bad function to use in interactive programs because it	1985	This is a very bad function to use in interactive programs because it
1916	blocks, and a bad way to reduce concurrency because it is inexact: Better	1986	blocks, and a bad way to reduce concurrency because it is inexact: Better
1917	use an C<aio_group> together with a feed callback.	1987	use an C<aio_group> together with a feed callback.
1918		1988
1919	It's main use is in scripts without an event loop - when you want to stat	1989	Its main use is in scripts without an event loop - when you want to stat
1920	a lot of files, you can write somehting like this:	1990	a lot of files, you can write somehting like this:
1921		1991
1922	IO::AIO::max_outstanding 32;	1992	IO::AIO::max_outstanding 32;
1923		1993
1924	for my $path (...) {	1994	for my $path (...) {
…		…
1964		2034
1965	=back	2035	=back
1966		2036
1967	=head3 MISCELLANEOUS FUNCTIONS	2037	=head3 MISCELLANEOUS FUNCTIONS
1968		2038
1969	IO::AIO implements some functions that might be useful, but are not	2039	IO::AIO implements some functions that are useful when you want to use
1970	asynchronous.	2040	some "Advanced I/O" function not available to in Perl, without going the
		2041	"Asynchronous I/O" route. Many of these have an asynchronous C<aio_*>
		2042	counterpart.
1971		2043
1972	=over 4	2044	=over 4
1973		2045
1974	=item IO::AIO::sendfile $ofh, $ifh, $offset, $count	2046	=item IO::AIO::sendfile $ofh, $ifh, $offset, $count
1975		2047
…		…
1994	=item IO::AIO::madvise $scalar, $offset, $len, $advice	2066	=item IO::AIO::madvise $scalar, $offset, $len, $advice
1995		2067
1996	Simply calls the C<posix_madvise> function (see its	2068	Simply calls the C<posix_madvise> function (see its
1997	manpage for details). The following advice constants are	2069	manpage for details). The following advice constants are
1998	available: C<IO::AIO::MADV_NORMAL>, C<IO::AIO::MADV_SEQUENTIAL>,	2070	available: C<IO::AIO::MADV_NORMAL>, C<IO::AIO::MADV_SEQUENTIAL>,
1999	C<IO::AIO::MADV_RANDOM>, C<IO::AIO::MADV_WILLNEED>, C<IO::AIO::MADV_DONTNEED>.	2071	C<IO::AIO::MADV_RANDOM>, C<IO::AIO::MADV_WILLNEED>, C<IO::AIO::MADV_DONTNEED>,
		2072	C<IO::AIO::MADV_FREE>.
2000		2073
2001	On systems that do not implement C<posix_madvise>, this function returns	2074	On systems that do not implement C<posix_madvise>, this function returns
2002	ENOSYS, otherwise the return value of C<posix_madvise>.	2075	ENOSYS, otherwise the return value of C<posix_madvise>.
2003		2076
2004	=item IO::AIO::mprotect $scalar, $offset, $len, $protect	2077	=item IO::AIO::mprotect $scalar, $offset, $len, $protect
…		…
2034	filesize.	2107	filesize.
2035		2108
2036	C<$prot> is a combination of C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_EXEC>,	2109	C<$prot> is a combination of C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_EXEC>,
2037	C<IO::AIO::PROT_READ> and/or C<IO::AIO::PROT_WRITE>,	2110	C<IO::AIO::PROT_READ> and/or C<IO::AIO::PROT_WRITE>,
2038		2111
2039	C<$flags> can be a combination of C<IO::AIO::MAP_SHARED> or	2112	C<$flags> can be a combination of
2040	C<IO::AIO::MAP_PRIVATE>, or a number of system-specific flags (when	2113	C<IO::AIO::MAP_SHARED> or
2041	not available, the are defined as 0): C<IO::AIO::MAP_ANONYMOUS>	2114	C<IO::AIO::MAP_PRIVATE>,
		2115	or a number of system-specific flags (when not available, the are C<0>):
2042	(which is set to C<MAP_ANON> if your system only provides this	2116	C<IO::AIO::MAP_ANONYMOUS> (which is set to C<MAP_ANON> if your system only provides this constant),
2043	constant), C<IO::AIO::MAP_HUGETLB>, C<IO::AIO::MAP_LOCKED>,	2117	C<IO::AIO::MAP_LOCKED>,
2044	C<IO::AIO::MAP_NORESERVE>, C<IO::AIO::MAP_POPULATE> or	2118	C<IO::AIO::MAP_NORESERVE>,
		2119	C<IO::AIO::MAP_POPULATE>,
2045	C<IO::AIO::MAP_NONBLOCK>	2120	C<IO::AIO::MAP_NONBLOCK>,
		2121	C<IO::AIO::MAP_FIXED>,
		2122	C<IO::AIO::MAP_GROWSDOWN>,
		2123	C<IO::AIO::MAP_32BIT>,
		2124	C<IO::AIO::MAP_HUGETLB> or
		2125	C<IO::AIO::MAP_STACK>.
2046		2126
2047	If C<$fh> is C<undef>, then a file descriptor of C<-1> is passed.	2127	If C<$fh> is C<undef>, then a file descriptor of C<-1> is passed.
2048		2128
2049	C<$offset> is the offset from the start of the file - it generally must be	2129	C<$offset> is the offset from the start of the file - it generally must be
2050	a multiple of C<IO::AIO::PAGESIZE> and defaults to C<0>.	2130	a multiple of C<IO::AIO::PAGESIZE> and defaults to C<0>.
…		…
2093		2173
2094	See the C<splice(2)> manpage for details.	2174	See the C<splice(2)> manpage for details.
2095		2175
2096	=item IO::AIO::tee $r_fh, $w_fh, $length, $flags	2176	=item IO::AIO::tee $r_fh, $w_fh, $length, $flags
2097		2177
2098	Calls the GNU/Linux C<tee(2)> syscall, see it's manpage and the	2178	Calls the GNU/Linux C<tee(2)> syscall, see its manpage and the
2099	description for C<IO::AIO::splice> above for details.	2179	description for C<IO::AIO::splice> above for details.
		2180
		2181	=item $actual_size = IO::AIO::pipesize $r_fh[, $new_size]
		2182
		2183	Attempts to query or change the pipe buffer size. Obviously works only
		2184	on pipes, and currently works only on GNU/Linux systems, and fails with
		2185	C<-1>/C<ENOSYS> everywhere else. If anybody knows how to influence pipe buffer
		2186	size on other systems, drop me a note.
		2187
		2188	=item ($rfh, $wfh) = IO::AIO::pipe2 [$flags]
		2189
		2190	This is a direct interface to the Linux L<pipe2(2)> system call. If
		2191	C<$flags> is missing or C<0>, then this should be the same as a call to
		2192	perl's built-in C<pipe> function and create a new pipe, and works on
		2193	systems that lack the pipe2 syscall. On win32, this case invokes C<_pipe
		2194	(..., 4096, O_BINARY)>.
		2195
		2196	If C<$flags> is non-zero, it tries to invoke the pipe2 system call with
		2197	the given flags (Linux 2.6.27, glibc 2.9).
		2198
		2199	On success, the read and write file handles are returned.
		2200
		2201	On error, nothing will be returned. If the pipe2 syscall is missing and
		2202	C<$flags> is non-zero, fails with C<ENOSYS>.
		2203
		2204	Please refer to L<pipe2(2)> for more info on the C<$flags>, but at the
		2205	time of this writing, C<IO::AIO::O_CLOEXEC>, C<IO::AIO::O_NONBLOCK> and
		2206	C<IO::AIO::O_DIRECT> (Linux 3.4, for packet-based pipes) were supported.
2100		2207
2101	=back	2208	=back
2102		2209
2103	=cut	2210	=cut
2104		2211

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Comparing IO-AIO/AIO.pm (file contents): Revision 1.235 by root, Wed Aug 22 22:28:03 2012 UTC vs. Revision 1.267 by root, Tue Aug 9 11:39:17 2016 UTC

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Comparing IO-AIO/AIO.pm (file contents):
Revision 1.235 by root, Wed Aug 22 22:28:03 2012 UTC vs.
Revision 1.267 by root, Tue Aug 9 11:39:17 2016 UTC