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

Comparing IO-AIO/AIO.pm (file contents):
Revision 1.229 by root, Wed Jul 25 16:32:30 2012 UTC vs.
Revision 1.280 by root, Mon Feb 19 13:37:13 2018 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 = '4.15';	176	our $VERSION = 4.4;
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_rename2 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
		188	aio_slurp
185	aio_wd);	189	aio_wd);
186		190
187	our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice));	191	our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice));
188	our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush	192	our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush
189	min_parallel max_parallel max_idle idle_timeout	193	min_parallel max_parallel max_idle idle_timeout
…		…
202		206
203	=head1 FUNCTIONS	207	=head1 FUNCTIONS
204		208
205	=head2 QUICK OVERVIEW	209	=head2 QUICK OVERVIEW
206		210
207	This section simply lists the prototypes of the most important functions	211	This section simply lists the prototypes most of the functions for
208	for quick reference. See the following sections for function-by-function	212	quick reference. See the following sections for function-by-function
209	documentation.	213	documentation.
210		214
211	aio_wd $pathname, $callback->($wd)	215	aio_wd $pathname, $callback->($wd)
212	aio_open $pathname, $flags, $mode, $callback->($fh)	216	aio_open $pathname, $flags, $mode, $callback->($fh)
213	aio_close $fh, $callback->($status)	217	aio_close $fh, $callback->($status)
…		…
222	aio_utime $fh_or_path, $atime, $mtime, $callback->($status)	226	aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
223	aio_chown $fh_or_path, $uid, $gid, $callback->($status)	227	aio_chown $fh_or_path, $uid, $gid, $callback->($status)
224	aio_chmod $fh_or_path, $mode, $callback->($status)	228	aio_chmod $fh_or_path, $mode, $callback->($status)
225	aio_truncate $fh_or_path, $offset, $callback->($status)	229	aio_truncate $fh_or_path, $offset, $callback->($status)
226	aio_allocate $fh, $mode, $offset, $len, $callback->($status)	230	aio_allocate $fh, $mode, $offset, $len, $callback->($status)
		231	aio_fiemap $fh, $start, $length, $flags, $count, $cb->(\@extents)
227	aio_unlink $pathname, $callback->($status)	232	aio_unlink $pathname, $callback->($status)
228	aio_mknod $pathname, $mode, $dev, $callback->($status)	233	aio_mknod $pathname, $mode, $dev, $callback->($status)
229	aio_link $srcpath, $dstpath, $callback->($status)	234	aio_link $srcpath, $dstpath, $callback->($status)
230	aio_symlink $srcpath, $dstpath, $callback->($status)	235	aio_symlink $srcpath, $dstpath, $callback->($status)
231	aio_readlink $pathname, $callback->($link)	236	aio_readlink $pathname, $callback->($link)
232	aio_realpath $pathname, $callback->($link)	237	aio_realpath $pathname, $callback->($path)
233	aio_rename $srcpath, $dstpath, $callback->($status)	238	aio_rename $srcpath, $dstpath, $callback->($status)
		239	aio_rename2 $srcpath, $dstpath, $flags, $callback->($status)
234	aio_mkdir $pathname, $mode, $callback->($status)	240	aio_mkdir $pathname, $mode, $callback->($status)
235	aio_rmdir $pathname, $callback->($status)	241	aio_rmdir $pathname, $callback->($status)
236	aio_readdir $pathname, $callback->($entries)	242	aio_readdir $pathname, $callback->($entries)
237	aio_readdirx $pathname, $flags, $callback->($entries, $flags)	243	aio_readdirx $pathname, $flags, $callback->($entries, $flags)
238	IO::AIO::READDIR_DENTS IO::AIO::READDIR_DIRS_FIRST	244	IO::AIO::READDIR_DENTS IO::AIO::READDIR_DIRS_FIRST
…		…
240	aio_scandir $pathname, $maxreq, $callback->($dirs, $nondirs)	246	aio_scandir $pathname, $maxreq, $callback->($dirs, $nondirs)
241	aio_load $pathname, $data, $callback->($status)	247	aio_load $pathname, $data, $callback->($status)
242	aio_copy $srcpath, $dstpath, $callback->($status)	248	aio_copy $srcpath, $dstpath, $callback->($status)
243	aio_move $srcpath, $dstpath, $callback->($status)	249	aio_move $srcpath, $dstpath, $callback->($status)
244	aio_rmtree $pathname, $callback->($status)	250	aio_rmtree $pathname, $callback->($status)
		251	aio_fcntl $fh, $cmd, $arg, $callback->($status)
		252	aio_ioctl $fh, $request, $buf, $callback->($status)
245	aio_sync $callback->($status)	253	aio_sync $callback->($status)
246	aio_syncfs $fh, $callback->($status)	254	aio_syncfs $fh, $callback->($status)
247	aio_fsync $fh, $callback->($status)	255	aio_fsync $fh, $callback->($status)
248	aio_fdatasync $fh, $callback->($status)	256	aio_fdatasync $fh, $callback->($status)
249	aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status)	257	aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status)
250	aio_pathsync $pathname, $callback->($status)	258	aio_pathsync $pathname, $callback->($status)
251	aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)	259	aio_msync $scalar, $offset = 0, $length = undef, flags = MS_SYNC, $callback->($status)
252	aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)	260	aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
253	aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status)	261	aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status)
254	aio_mlockall $flags, $callback->($status)	262	aio_mlockall $flags, $callback->($status)
255	aio_group $callback->(...)	263	aio_group $callback->(...)
256	aio_nop $callback->()	264	aio_nop $callback->()
…		…
270	IO::AIO::idle_timeout $seconds	278	IO::AIO::idle_timeout $seconds
271	IO::AIO::max_outstanding $maxreqs	279	IO::AIO::max_outstanding $maxreqs
272	IO::AIO::nreqs	280	IO::AIO::nreqs
273	IO::AIO::nready	281	IO::AIO::nready
274	IO::AIO::npending	282	IO::AIO::npending
		283	$nfd = IO::AIO::get_fdlimit [EXPERIMENTAL]
		284	IO::AIO::min_fdlimit $nfd [EXPERIMENTAL]
275		285
276	IO::AIO::sendfile $ofh, $ifh, $offset, $count	286	IO::AIO::sendfile $ofh, $ifh, $offset, $count
277	IO::AIO::fadvise $fh, $offset, $len, $advice	287	IO::AIO::fadvise $fh, $offset, $len, $advice
278	IO::AIO::mmap $scalar, $length, $prot, $flags[, $fh[, $offset]]	288	IO::AIO::mmap $scalar, $length, $prot, $flags[, $fh[, $offset]]
279	IO::AIO::munmap $scalar	289	IO::AIO::munmap $scalar
…		…
361		371
362		372
363	=item aio_open $pathname, $flags, $mode, $callback->($fh)	373	=item aio_open $pathname, $flags, $mode, $callback->($fh)
364		374
365	Asynchronously open or create a file and call the callback with a newly	375	Asynchronously open or create a file and call the callback with a newly
366	created filehandle for the file.	376	created filehandle for the file (or C<undef> in case of an error).
367		377
368	The pathname passed to C<aio_open> must be absolute. See API NOTES, above,	378	The pathname passed to C<aio_open> must be absolute. See API NOTES, above,
369	for an explanation.	379	for an explanation.
370		380
371	The C<$flags> argument is a bitmask. See the C<Fcntl> module for a	381	The C<$flags> argument is a bitmask. See the C<Fcntl> module for a
…		…
394	following POSIX and non-POSIX constants are available (missing ones on	404	following POSIX and non-POSIX constants are available (missing ones on
395	your system are, as usual, C<0>):	405	your system are, as usual, C<0>):
396		406
397	C<O_ASYNC>, C<O_DIRECT>, C<O_NOATIME>, C<O_CLOEXEC>, C<O_NOCTTY>, C<O_NOFOLLOW>,	407	C<O_ASYNC>, C<O_DIRECT>, C<O_NOATIME>, C<O_CLOEXEC>, C<O_NOCTTY>, C<O_NOFOLLOW>,
398	C<O_NONBLOCK>, C<O_EXEC>, C<O_SEARCH>, C<O_DIRECTORY>, C<O_DSYNC>,	408	C<O_NONBLOCK>, C<O_EXEC>, C<O_SEARCH>, C<O_DIRECTORY>, C<O_DSYNC>,
399	C<O_RSYNC>, C<O_SYNC> and C<O_TTY_INIT>.	409	C<O_RSYNC>, C<O_SYNC>, C<O_PATH>, C<O_TMPFILE>, and C<O_TTY_INIT>.
400		410
401		411
402	=item aio_close $fh, $callback->($status)	412	=item aio_close $fh, $callback->($status)
403		413
404	Asynchronously close a file and call the callback with the result	414	Asynchronously close a file and call the callback with the result
…		…
439	=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)	449	=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
440		450
441	=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)	451	=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
442		452
443	Reads or writes C<$length> bytes from or to the specified C<$fh> and	453	Reads or writes C<$length> bytes from or to the specified C<$fh> and
444	C<$offset> into the scalar given by C<$data> and offset C<$dataoffset>	454	C<$offset> into the scalar given by C<$data> and offset C<$dataoffset> and
445	and calls the callback without the actual number of bytes read (or -1 on	455	calls the callback with the actual number of bytes transferred (or -1 on
446	error, just like the syscall).	456	error, just like the syscall).
447		457
448	C<aio_read> will, like C<sysread>, shrink or grow the C<$data> scalar to	458	C<aio_read> will, like C<sysread>, shrink or grow the C<$data> scalar to
449	offset plus the actual number of bytes read.	459	offset plus the actual number of bytes read.
450		460
…		…
508	As native sendfile syscalls (as practically any non-POSIX interface hacked	518	As native sendfile syscalls (as practically any non-POSIX interface hacked
509	together in a hurry to improve benchmark numbers) tend to be rather buggy	519	together in a hurry to improve benchmark numbers) tend to be rather buggy
510	on many systems, this implementation tries to work around some known bugs	520	on many systems, this implementation tries to work around some known bugs
511	in Linux and FreeBSD kernels (probably others, too), but that might fail,	521	in Linux and FreeBSD kernels (probably others, too), but that might fail,
512	so you really really should check the return value of C<aio_sendfile> -	522	so you really really should check the return value of C<aio_sendfile> -
513	fewre bytes than expected might have been transferred.	523	fewer bytes than expected might have been transferred.
514		524
515		525
516	=item aio_readahead $fh,$offset,$length, $callback->($retval)	526	=item aio_readahead $fh,$offset,$length, $callback->($retval)
517		527
518	C<aio_readahead> populates the page cache with data from a file so that	528	C<aio_readahead> populates the page cache with data from a file so that
…		…
522	whole pages, so that offset is effectively rounded down to a page boundary	532	whole pages, so that offset is effectively rounded down to a page boundary
523	and bytes are read up to the next page boundary greater than or equal to	533	and bytes are read up to the next page boundary greater than or equal to
524	(off-set+length). C<aio_readahead> does not read beyond the end of the	534	(off-set+length). C<aio_readahead> does not read beyond the end of the
525	file. The current file offset of the file is left unchanged.	535	file. The current file offset of the file is left unchanged.
526		536
527	If that syscall doesn't exist (likely if your OS isn't Linux) it will be	537	If that syscall doesn't exist (likely if your kernel isn't Linux) it will
528	emulated by simply reading the data, which would have a similar effect.	538	be emulated by simply reading the data, which would have a similar effect.
529		539
530		540
531	=item aio_stat $fh_or_path, $callback->($status)	541	=item aio_stat $fh_or_path, $callback->($status)
532		542
533	=item aio_lstat $fh, $callback->($status)	543	=item aio_lstat $fh, $callback->($status)
…		…
602	namemax => 255,	612	namemax => 255,
603	frsize => 1024,	613	frsize => 1024,
604	fsid => 1810	614	fsid => 1810
605	}	615	}
606		616
607
608	=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status)	617	=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
609		618
610	Works like perl's C<utime> function (including the special case of $atime	619	Works like perl's C<utime> function (including the special case of $atime
611	and $mtime being undef). Fractional times are supported if the underlying	620	and $mtime being undef). Fractional times are supported if the underlying
612	syscalls support them.	621	syscalls support them.
…		…
641	Works like truncate(2) or ftruncate(2).	650	Works like truncate(2) or ftruncate(2).
642		651
643		652
644	=item aio_allocate $fh, $mode, $offset, $len, $callback->($status)	653	=item aio_allocate $fh, $mode, $offset, $len, $callback->($status)
645		654
646	Allocates or freed disk space according to the C<$mode> argument. See the	655	Allocates or frees disk space according to the C<$mode> argument. See the
647	linux C<fallocate> docuemntation for details.	656	linux C<fallocate> documentation for details.
648		657
649	C<$mode> can currently be C<0> or C<IO::AIO::FALLOC_FL_KEEP_SIZE>	658	C<$mode> is usually C<0> or C<IO::AIO::FALLOC_FL_KEEP_SIZE> to allocate
650	to allocate space, or C<IO::AIO::FALLOC_FL_PUNCH_HOLE \|	659	space, or C<IO::AIO::FALLOC_FL_PUNCH_HOLE \| IO::AIO::FALLOC_FL_KEEP_SIZE>,
651	IO::AIO::FALLOC_FL_KEEP_SIZE>, to deallocate a file range.	660	to deallocate a file range.
		661
		662	IO::AIO also supports C<FALLOC_FL_COLLAPSE_RANGE>, to remove a range
		663	(without leaving a hole), C<FALLOC_FL_ZERO_RANGE>, to zero a range,
		664	C<FALLOC_FL_INSERT_RANGE> to insert a range and C<FALLOC_FL_UNSHARE_RANGE>
		665	to unshare shared blocks (see your L<fallocate(2)> manpage).
652		666
653	The file system block size used by C<fallocate> is presumably the	667	The file system block size used by C<fallocate> is presumably the
654	C<f_bsize> returned by C<statvfs>.	668	C<f_bsize> returned by C<statvfs>, but different filesystems and filetypes
		669	can dictate other limitations.
655		670
656	If C<fallocate> isn't available or cannot be emulated (currently no	671	If C<fallocate> isn't available or cannot be emulated (currently no
657	emulation will be attempted), passes C<-1> and sets C<$!> to C<ENOSYS>.	672	emulation will be attempted), passes C<-1> and sets C<$!> to C<ENOSYS>.
658		673
659		674
…		…
701		716
702		717
703	=item aio_realpath $pathname, $callback->($path)	718	=item aio_realpath $pathname, $callback->($path)
704		719
705	Asynchronously make the path absolute and resolve any symlinks in	720	Asynchronously make the path absolute and resolve any symlinks in
706	C<$path>. The resulting path only consists of directories (Same as	721	C<$path>. The resulting path only consists of directories (same as
707	L<Cwd::realpath>).	722	L<Cwd::realpath>).
708		723
709	This request can be used to get the absolute path of the current working	724	This request can be used to get the absolute path of the current working
710	directory by passing it a path of F<.> (a single dot).	725	directory by passing it a path of F<.> (a single dot).
711		726
712		727
713	=item aio_rename $srcpath, $dstpath, $callback->($status)	728	=item aio_rename $srcpath, $dstpath, $callback->($status)
714		729
715	Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as	730	Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as
716	rename(2) and call the callback with the result code.	731	rename(2) and call the callback with the result code.
		732
		733	On systems that support the AIO::WD working directory abstraction
		734	natively, the case C<[$wd, "."]> as C<$srcpath> is specialcased - instead
		735	of failing, C<rename> is called on the absolute path of C<$wd>.
		736
		737
		738	=item aio_rename2 $srcpath, $dstpath, $flags, $callback->($status)
		739
		740	Basically a version of C<aio_rename> with an additional C<$flags>
		741	argument. Calling this with C<$flags=0> is the same as calling
		742	C<aio_rename>.
		743
		744	Non-zero flags are currently only supported on GNU/Linux systems that
		745	support renameat2. Other systems fail with C<ENOSYS> in this case.
		746
		747	The following constants are available (missing ones are, as usual C<0>),
		748	see renameat2(2) for details:
		749
		750	C<IO::AIO::RENAME_NOREPLACE>, C<IO::AIO::RENAME_EXCHANGE>
		751	and C<IO::AIO::RENAME_WHITEOUT>.
717		752
718		753
719	=item aio_mkdir $pathname, $mode, $callback->($status)	754	=item aio_mkdir $pathname, $mode, $callback->($status)
720		755
721	Asynchronously mkdir (create) a directory and call the callback with	756	Asynchronously mkdir (create) a directory and call the callback with
…		…
725		760
726	=item aio_rmdir $pathname, $callback->($status)	761	=item aio_rmdir $pathname, $callback->($status)
727		762
728	Asynchronously rmdir (delete) a directory and call the callback with the	763	Asynchronously rmdir (delete) a directory and call the callback with the
729	result code.	764	result code.
		765
		766	On systems that support the AIO::WD working directory abstraction
		767	natively, the case C<[$wd, "."]> is specialcased - instead of failing,
		768	C<rmdir> is called on the absolute path of C<$wd>.
730		769
731		770
732	=item aio_readdir $pathname, $callback->($entries)	771	=item aio_readdir $pathname, $callback->($entries)
733		772
734	Unlike the POSIX call of the same name, C<aio_readdir> reads an entire	773	Unlike the POSIX call of the same name, C<aio_readdir> reads an entire
…		…
803	C<$type>'s are known, which can be used to speed up some algorithms.	842	C<$type>'s are known, which can be used to speed up some algorithms.
804		843
805	=back	844	=back
806		845
807		846
		847	=item aio_slurp $pathname, $offset, $length, $data, $callback->($status)
		848
		849	Opens, reads and closes the given file. The data is put into C<$data>,
		850	which is resized as required.
		851
		852	If C<$offset> is negative, then it is counted from the end of the file.
		853
		854	If C<$length> is zero, then the remaining length of the file is
		855	used. Also, in this case, the same limitations to modifying C<$data> apply
		856	as when IO::AIO::mmap is used, i.e. it must only be modified in-place
		857	with C<substr>. If the size of the file is known, specifying a non-zero
		858	C<$length> results in a performance advantage.
		859
		860	This request is similar to the older C<aio_load> request, but since it is
		861	a single request, it might be more efficient to use.
		862
		863	Example: load F</etc/passwd> into C<$passwd>.
		864
		865	my $passwd;
		866	aio_slurp "/etc/passwd", 0, 0, $passwd, sub {
		867	$_[0] >= 0
		868	or die "/etc/passwd: $!\n";
		869
		870	printf "/etc/passwd is %d bytes long, and contains:\n", length $passwd;
		871	print $passwd;
		872	};
		873	IO::AIO::flush;
		874
		875
808	=item aio_load $pathname, $data, $callback->($status)	876	=item aio_load $pathname, $data, $callback->($status)
809		877
810	This is a composite request that tries to fully load the given file into	878	This is a composite request that tries to fully load the given file into
811	memory. Status is the same as with aio_read.	879	memory. Status is the same as with aio_read.
		880
		881	Using C<aio_slurp> might be more efficient, as it is a single request.
812		882
813	=cut	883	=cut
814		884
815	sub aio_load($$;$) {	885	sub aio_load($$;$) {
816	my ($path, undef, $cb) = @_;	886	my ($path, undef, $cb) = @_;
…		…
836	=item aio_copy $srcpath, $dstpath, $callback->($status)	906	=item aio_copy $srcpath, $dstpath, $callback->($status)
837		907
838	Try to copy the I<file> (directories not supported as either source or	908	Try to copy the I<file> (directories not supported as either source or
839	destination) from C<$srcpath> to C<$dstpath> and call the callback with	909	destination) from C<$srcpath> to C<$dstpath> and call the callback with
840	a status of C<0> (ok) or C<-1> (error, see C<$!>).	910	a status of C<0> (ok) or C<-1> (error, see C<$!>).
		911
		912	Existing destination files will be truncated.
841		913
842	This is a composite request that creates the destination file with	914	This is a composite request that creates the destination file with
843	mode 0200 and copies the contents of the source file into it using	915	mode 0200 and copies the contents of the source file into it using
844	C<aio_sendfile>, followed by restoring atime, mtime, access mode and	916	C<aio_sendfile>, followed by restoring atime, mtime, access mode and
845	uid/gid, in that order.	917	uid/gid, in that order.
…		…
955	Scans a directory (similar to C<aio_readdir>) but additionally tries to	1027	Scans a directory (similar to C<aio_readdir>) but additionally tries to
956	efficiently separate the entries of directory C<$path> into two sets of	1028	efficiently separate the entries of directory C<$path> into two sets of
957	names, directories you can recurse into (directories), and ones you cannot	1029	names, directories you can recurse into (directories), and ones you cannot
958	recurse into (everything else, including symlinks to directories).	1030	recurse into (everything else, including symlinks to directories).
959		1031
960	C<aio_scandir> is a composite request that creates of many sub requests_	1032	C<aio_scandir> is a composite request that generates many sub requests.
961	C<$maxreq> specifies the maximum number of outstanding aio requests that	1033	C<$maxreq> specifies the maximum number of outstanding aio requests that
962	this function generates. If it is C<< <= 0 >>, then a suitable default	1034	this function generates. If it is C<< <= 0 >>, then a suitable default
963	will be chosen (currently 4).	1035	will be chosen (currently 4).
964		1036
965	On error, the callback is called without arguments, otherwise it receives	1037	On error, the callback is called without arguments, otherwise it receives
…		…
1099	}	1171	}
1100		1172
1101	=item aio_rmtree $pathname, $callback->($status)	1173	=item aio_rmtree $pathname, $callback->($status)
1102		1174
1103	Delete a directory tree starting (and including) C<$path>, return the	1175	Delete a directory tree starting (and including) C<$path>, return the
1104	status of the final C<rmdir> only. This is a composite request that	1176	status of the final C<rmdir> only. This is a composite request that
1105	uses C<aio_scandir> to recurse into and rmdir directories, and unlink	1177	uses C<aio_scandir> to recurse into and rmdir directories, and unlink
1106	everything else.	1178	everything else.
1107		1179
1108	=cut	1180	=cut
1109		1181
…		…
1130	add $grp $dirgrp;	1202	add $grp $dirgrp;
1131	};	1203	};
1132		1204
1133	$grp	1205	$grp
1134	}	1206	}
		1207
		1208	=item aio_fcntl $fh, $cmd, $arg, $callback->($status)
		1209
		1210	=item aio_ioctl $fh, $request, $buf, $callback->($status)
		1211
		1212	These work just like the C<fcntl> and C<ioctl> built-in functions, except
		1213	they execute asynchronously and pass the return value to the callback.
		1214
		1215	Both calls can be used for a lot of things, some of which make more sense
		1216	to run asynchronously in their own thread, while some others make less
		1217	sense. For example, calls that block waiting for external events, such
		1218	as locking, will also lock down an I/O thread while it is waiting, which
		1219	can deadlock the whole I/O system. At the same time, there might be no
		1220	alternative to using a thread to wait.
		1221
		1222	So in general, you should only use these calls for things that do
		1223	(filesystem) I/O, not for things that wait for other events (network,
		1224	other processes), although if you are careful and know what you are doing,
		1225	you still can.
		1226
		1227	The following constants are available (missing ones are, as usual C<0>):
		1228
		1229	C<F_DUPFD_CLOEXEC>,
		1230
		1231	C<F_OFD_GETLK>, C<F_OFD_SETLK>, C<F_OFD_GETLKW>,
		1232
		1233	C<FIFREEZE>, C<FITHAW>, C<FITRIM>, C<FICLONE>, C<FICLONERANGE>, C<FIDEDUPERANGE>.
		1234
		1235	C<FS_IOC_GETFLAGS>, C<FS_IOC_SETFLAGS>, C<FS_IOC_GETVERSION>, C<FS_IOC_SETVERSION>,
		1236	C<FS_IOC_FIEMAP>.
		1237
		1238	C<FS_IOC_FSGETXATTR>, C<FS_IOC_FSSETXATTR>, C<FS_IOC_SET_ENCRYPTION_POLICY>,
		1239	C<FS_IOC_GET_ENCRYPTION_PWSALT>, C<FS_IOC_GET_ENCRYPTION_POLICY>, C<FS_KEY_DESCRIPTOR_SIZE>.
		1240
		1241	C<FS_SECRM_FL>, C<FS_UNRM_FL>, C<FS_COMPR_FL>, C<FS_SYNC_FL>, C<FS_IMMUTABLE_FL>,
		1242	C<FS_APPEND_FL>, C<FS_NODUMP_FL>, C<FS_NOATIME_FL>, C<FS_DIRTY_FL>,
		1243	C<FS_COMPRBLK_FL>, C<FS_NOCOMP_FL>, C<FS_ENCRYPT_FL>, C<FS_BTREE_FL>,
		1244	C<FS_INDEX_FL>, C<FS_JOURNAL_DATA_FL>, C<FS_NOTAIL_FL>, C<FS_DIRSYNC_FL>, C<FS_TOPDIR_FL>,
		1245	C<FS_FL_USER_MODIFIABLE>.
		1246
		1247	C<FS_XFLAG_REALTIME>, C<FS_XFLAG_PREALLOC>, C<FS_XFLAG_IMMUTABLE>, C<FS_XFLAG_APPEND>,
		1248	C<FS_XFLAG_SYNC>, C<FS_XFLAG_NOATIME>, C<FS_XFLAG_NODUMP>, C<FS_XFLAG_RTINHERIT>,
		1249	C<FS_XFLAG_PROJINHERIT>, C<FS_XFLAG_NOSYMLINKS>, C<FS_XFLAG_EXTSIZE>, C<FS_XFLAG_EXTSZINHERIT>,
		1250	C<FS_XFLAG_NODEFRAG>, C<FS_XFLAG_FILESTREAM>, C<FS_XFLAG_DAX>, C<FS_XFLAG_HASATTR>,
1135		1251
1136	=item aio_sync $callback->($status)	1252	=item aio_sync $callback->($status)
1137		1253
1138	Asynchronously call sync and call the callback when finished.	1254	Asynchronously call sync and call the callback when finished.
1139		1255
…		…
1208	};	1324	};
1209		1325
1210	$grp	1326	$grp
1211	}	1327	}
1212		1328
1213	=item aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)	1329	=item aio_msync $scalar, $offset = 0, $length = undef, flags = MS_SYNC, $callback->($status)
1214		1330
1215	This is a rather advanced IO::AIO call, which only works on mmap(2)ed	1331	This is a rather advanced IO::AIO call, which only works on mmap(2)ed
1216	scalars (see the C<IO::AIO::mmap> function, although it also works on data	1332	scalars (see the C<IO::AIO::mmap> function, although it also works on data
1217	scalars managed by the L<Sys::Mmap> or L<Mmap> modules, note that the	1333	scalars managed by the L<Sys::Mmap> or L<Mmap> modules, note that the
1218	scalar must only be modified in-place while an aio operation is pending on	1334	scalar must only be modified in-place while an aio operation is pending on
…		…
1220		1336
1221	It calls the C<msync> function of your OS, if available, with the memory	1337	It calls the C<msync> function of your OS, if available, with the memory
1222	area starting at C<$offset> in the string and ending C<$length> bytes	1338	area starting at C<$offset> in the string and ending C<$length> bytes
1223	later. If C<$length> is negative, counts from the end, and if C<$length>	1339	later. If C<$length> is negative, counts from the end, and if C<$length>
1224	is C<undef>, then it goes till the end of the string. The flags can be	1340	is C<undef>, then it goes till the end of the string. The flags can be
1225	a combination of C<IO::AIO::MS_ASYNC>, C<IO::AIO::MS_INVALIDATE> and	1341	either C<IO::AIO::MS_ASYNC> or C<IO::AIO::MS_SYNC>, plus an optional
1226	C<IO::AIO::MS_SYNC>.	1342	C<IO::AIO::MS_INVALIDATE>.
1227		1343
1228	=item aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)	1344	=item aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
1229		1345
1230	This is a rather advanced IO::AIO call, which works best on mmap(2)ed	1346	This is a rather advanced IO::AIO call, which works best on mmap(2)ed
1231	scalars.	1347	scalars.
1232		1348
1233	It touches (reads or writes) all memory pages in the specified	1349	It touches (reads or writes) all memory pages in the specified
1234	range inside the scalar. All caveats and parameters are the same	1350	range inside the scalar. All caveats and parameters are the same
1235	as for C<aio_msync>, above, except for flags, which must be either	1351	as for C<aio_msync>, above, except for flags, which must be either
1236	C<0> (which reads all pages and ensures they are instantiated) or	1352	C<0> (which reads all pages and ensures they are instantiated) or
1237	C<IO::AIO::MT_MODIFY>, which modifies the memory page s(by reading and	1353	C<IO::AIO::MT_MODIFY>, which modifies the memory pages (by reading and
1238	writing an octet from it, which dirties the page).	1354	writing an octet from it, which dirties the page).
1239		1355
1240	=item aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status)	1356	=item aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status)
1241		1357
1242	This is a rather advanced IO::AIO call, which works best on mmap(2)ed	1358	This is a rather advanced IO::AIO call, which works best on mmap(2)ed
…		…
1276		1392
1277	aio_mlockall IO::AIO::MCL_FUTURE;	1393	aio_mlockall IO::AIO::MCL_FUTURE;
1278		1394
1279	=item aio_fiemap $fh, $start, $length, $flags, $count, $cb->(\@extents)	1395	=item aio_fiemap $fh, $start, $length, $flags, $count, $cb->(\@extents)
1280		1396
1281	Queries the extents of the given file (by calling the Linux FIEMAP ioctl,	1397	Queries the extents of the given file (by calling the Linux C<FIEMAP>
1282	see L<http://cvs.schmorp.de/IO-AIO/doc/fiemap.txt> for details). If the	1398	ioctl, see L<http://cvs.schmorp.de/IO-AIO/doc/fiemap.txt> for details). If
1283	C<ioctl> is not available on your OS, then this rquiest will fail with	1399	the ioctl is not available on your OS, then this request will fail with
1284	C<ENOSYS>.	1400	C<ENOSYS>.
1285		1401
1286	C<$start> is the starting offset to query extents for, C<$length> is the	1402	C<$start> is the starting offset to query extents for, C<$length> is the
1287	size of the range to query - if it is C<undef>, then the whole file will	1403	size of the range to query - if it is C<undef>, then the whole file will
1288	be queried.	1404	be queried.
…		…
1291	C<IO::AIO::FIEMAP_FLAG_XATTR> - C<IO::AIO::FIEMAP_FLAGS_COMPAT> is also	1407	C<IO::AIO::FIEMAP_FLAG_XATTR> - C<IO::AIO::FIEMAP_FLAGS_COMPAT> is also
1292	exported), and is normally C<0> or C<IO::AIO::FIEMAP_FLAG_SYNC> to query	1408	exported), and is normally C<0> or C<IO::AIO::FIEMAP_FLAG_SYNC> to query
1293	the data portion.	1409	the data portion.
1294		1410
1295	C<$count> is the maximum number of extent records to return. If it is	1411	C<$count> is the maximum number of extent records to return. If it is
1296	C<undef>, then IO::AIO queries all extents of the file. As a very special	1412	C<undef>, then IO::AIO queries all extents of the range. As a very special
1297	case, if it is C<0>, then the callback receives the number of extents	1413	case, if it is C<0>, then the callback receives the number of extents
1298	instead of the extents themselves.	1414	instead of the extents themselves (which is unreliable, see below).
1299		1415
1300	If an error occurs, the callback receives no arguments. The special	1416	If an error occurs, the callback receives no arguments. The special
1301	C<errno> value C<IO::AIO::EBADR> is available to test for flag errors.	1417	C<errno> value C<IO::AIO::EBADR> is available to test for flag errors.
1302		1418
1303	Otherwise, the callback receives an array reference with extent	1419	Otherwise, the callback receives an array reference with extent
…		…
1305	following members:	1421	following members:
1306		1422
1307	[$logical, $physical, $length, $flags]	1423	[$logical, $physical, $length, $flags]
1308		1424
1309	Flags is any combination of the following flag values (typically either C<0>	1425	Flags is any combination of the following flag values (typically either C<0>
1310	or C<IO::AIO::FIEMAP_EXTENT_LAST>):	1426	or C<IO::AIO::FIEMAP_EXTENT_LAST> (1)):
1311		1427
1312	C<IO::AIO::FIEMAP_EXTENT_LAST>, C<IO::AIO::FIEMAP_EXTENT_UNKNOWN>,	1428	C<IO::AIO::FIEMAP_EXTENT_LAST>, C<IO::AIO::FIEMAP_EXTENT_UNKNOWN>,
1313	C<IO::AIO::FIEMAP_EXTENT_DELALLOC>, C<IO::AIO::FIEMAP_EXTENT_ENCODED>,	1429	C<IO::AIO::FIEMAP_EXTENT_DELALLOC>, C<IO::AIO::FIEMAP_EXTENT_ENCODED>,
1314	C<IO::AIO::FIEMAP_EXTENT_DATA_ENCRYPTED>, C<IO::AIO::FIEMAP_EXTENT_NOT_ALIGNED>,	1430	C<IO::AIO::FIEMAP_EXTENT_DATA_ENCRYPTED>, C<IO::AIO::FIEMAP_EXTENT_NOT_ALIGNED>,
1315	C<IO::AIO::FIEMAP_EXTENT_DATA_INLINE>, C<IO::AIO::FIEMAP_EXTENT_DATA_TAIL>,	1431	C<IO::AIO::FIEMAP_EXTENT_DATA_INLINE>, C<IO::AIO::FIEMAP_EXTENT_DATA_TAIL>,
1316	C<IO::AIO::FIEMAP_EXTENT_UNWRITTEN>, C<IO::AIO::FIEMAP_EXTENT_MERGED> or	1432	C<IO::AIO::FIEMAP_EXTENT_UNWRITTEN>, C<IO::AIO::FIEMAP_EXTENT_MERGED> or
1317	C<IO::AIO::FIEMAP_EXTENT_SHARED>.	1433	C<IO::AIO::FIEMAP_EXTENT_SHARED>.
1318		1434
		1435	At the time of this writing (Linux 3.2), this request is unreliable unless
		1436	C<$count> is C<undef>, as the kernel has all sorts of bugs preventing
		1437	it to return all extents of a range for files with a large number of
		1438	extents. The code (only) works around all these issues if C<$count> is
		1439	C<undef>.
		1440
1319	=item aio_group $callback->(...)	1441	=item aio_group $callback->(...)
1320		1442
1321	This is a very special aio request: Instead of doing something, it is a	1443	This is a very special aio request: Instead of doing something, it is a
1322	container for other aio requests, which is useful if you want to bundle	1444	container for other aio requests, which is useful if you want to bundle
1323	many requests into a single, composite, request with a definite callback	1445	many requests into a single, composite, request with a definite callback
…		…
1406	aio_stat [$etcdir, "passwd"], sub {	1528	aio_stat [$etcdir, "passwd"], sub {
1407	# yay	1529	# yay
1408	};	1530	};
1409	};	1531	};
1410		1532
1411	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
1412	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,
1413	why it is done asynchronously.	1535	which is why it is done asynchronously.
1414		1536
1415	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
1416	either of the following three request calls:	1538	either of the following three request calls:
1417		1539
1418	aio_lstat "/etc" , sub { ... # pathname as normal string	1540	aio_lstat "/etc" , sub { ... # pathname as normal string
…		…
1435	There are some caveats: when directories get renamed (or deleted), the	1557	There are some caveats: when directories get renamed (or deleted), the
1436	pathname string doesn't change, so will point to the new directory (or	1558	pathname string doesn't change, so will point to the new directory (or
1437	nowhere at all), while the directory fd, if available on the system,	1559	nowhere at all), while the directory fd, if available on the system,
1438	will still point to the original directory. Most functions accepting a	1560	will still point to the original directory. Most functions accepting a
1439	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
1440	older systems. Some functions (such as realpath) will always rely on the	1562	older systems. Some functions (such as C<aio_realpath>) will always rely on
1441	string form of the pathname.	1563	the string form of the pathname.
1442		1564
1443	So this fucntionality is mainly useful to get some protection against	1565	So this functionality is mainly useful to get some protection against
1444	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
1445	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
1446	(e.g. when stat'ing all files in a directory).	1568	(e.g. when stat'ing all files in a directory).
1447		1569
1448	The following functions implement this working directory abstraction:	1570	The following functions implement this working directory abstraction:
…		…
1461	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
1462	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
1463	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
1464	expected way.	1586	expected way.
1465		1587
1466	If this call isn't available because your OS lacks it or it couldn't be
1467	detected, it will be emulated by calling C<fsync> instead.
1468
1469	=item IO::AIO::CWD	1588	=item IO::AIO::CWD
1470		1589
1471	This is a compiletime constant (object) that represents the process	1590	This is a compiletime constant (object) that represents the process
1472	current working directory.	1591	current working directory.
1473		1592
1474	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
1475	if the pathname would be specified directly, without a directory object,	1594	the pathname would be specified directly, without a directory object. For
1476	e.g., these calls are functionally identical:	1595	example, these calls are functionally identical:
1477		1596
1478	aio_stat "somefile", sub { ... };	1597	aio_stat "somefile", sub { ... };
1479	aio_stat [IO::AIO::CWD, "somefile"], sub { ... };	1598	aio_stat [IO::AIO::CWD, "somefile"], sub { ... };
1480		1599
1481	=back	1600	=back
1482		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.
1483		1611
1484	=head2 IO::AIO::REQ CLASS	1612	=head2 IO::AIO::REQ CLASS
1485		1613
1486	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
1487	called in non-void context.	1615	called in non-void context.
…		…
1665		1793
1666	See C<poll_cb> for an example.	1794	See C<poll_cb> for an example.
1667		1795
1668	=item IO::AIO::poll_cb	1796	=item IO::AIO::poll_cb
1669		1797
1670	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
1671	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
1672	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
1673	reason. Returns immediately when no events are outstanding. The amount of	1804	reason. Returns immediately when no events are outstanding. The amount
1674	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>,
1675	C<IO::AIO::max_poll_time>.	1806	C<IO::AIO::max_poll_time> and C<IO::AIO::max_outstanding>.
1676		1807
1677	If not all requests were processed for whatever reason, the filehandle	1808	If not all requests were processed for whatever reason, the poll file
1678	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
1679	do anything special to have it called later.	1810	don't have to do anything special to have it called later.
1680		1811
1681	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
1682	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
1683	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
1684	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
…		…
1693	poll => 'r', async => 1,	1824	poll => 'r', async => 1,
1694	cb => \&IO::AIO::poll_cb);	1825	cb => \&IO::AIO::poll_cb);
1695		1826
1696	=item IO::AIO::poll_wait	1827	=item IO::AIO::poll_wait
1697		1828
1698	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
1699	phase, wait till the result filehandle becomes ready for reading (simply	1830	requests are outstanding anymore.
1700	does a C<select> on the filehandle. This is useful if you want to	1831
1701	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.
1702		1834
1703	See C<nreqs> for an example.	1835	See C<nreqs> for an example.
1704		1836
1705	=item IO::AIO::poll	1837	=item IO::AIO::poll
1706		1838
…		…
1827		1959
1828	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
1829	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
1830	use an C<aio_group> together with a feed callback.	1962	use an C<aio_group> together with a feed callback.
1831		1963
1832	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
1833	a lot of files, you can write somehting like this:	1965	a lot of files, you can write something like this:
1834		1966
1835	IO::AIO::max_outstanding 32;	1967	IO::AIO::max_outstanding 32;
1836		1968
1837	for my $path (...) {	1969	for my $path (...) {
1838	aio_stat $path , ...;	1970	aio_stat $path , ...;
…		…
1877		2009
1878	=back	2010	=back
1879		2011
1880	=head3 MISCELLANEOUS FUNCTIONS	2012	=head3 MISCELLANEOUS FUNCTIONS
1881		2013
1882	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
1883	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.
1884		2018
1885	=over 4	2019	=over 4
		2020
		2021	=item $numfd = IO::AIO::get_fdlimit
		2022
		2023	This function is I<EXPERIMENTAL> and subject to change.
		2024
		2025	Tries to find the current file descriptor limit and returns it, or
		2026	C<undef> and sets C<$!> in case of an error. The limit is one larger than
		2027	the highest valid file descriptor number.
		2028
		2029	=item IO::AIO::min_fdlimit [$numfd]
		2030
		2031	This function is I<EXPERIMENTAL> and subject to change.
		2032
		2033	Try to increase the current file descriptor limit(s) to at least C<$numfd>
		2034	by changing the soft or hard file descriptor resource limit. If C<$numfd>
		2035	is missing, it will try to set a very high limit, although this is not
		2036	recommended when you know the actual minimum that you require.
		2037
		2038	If the limit cannot be raised enough, the function makes a best-effort
		2039	attempt to increase the limit as much as possible, using various
		2040	tricks, while still failing. You can query the resulting limit using
		2041	C<IO::AIO::get_fdlimit>.
		2042
		2043	If an error occurs, returns C<undef> and sets C<$!>, otherwise returns
		2044	true.
1886		2045
1887	=item IO::AIO::sendfile $ofh, $ifh, $offset, $count	2046	=item IO::AIO::sendfile $ofh, $ifh, $offset, $count
1888		2047
1889	Calls the C<eio_sendfile_sync> function, which is like C<aio_sendfile>,	2048	Calls the C<eio_sendfile_sync> function, which is like C<aio_sendfile>,
1890	but is blocking (this makes most sense if you know the input data is	2049	but is blocking (this makes most sense if you know the input data is
…		…
1907	=item IO::AIO::madvise $scalar, $offset, $len, $advice	2066	=item IO::AIO::madvise $scalar, $offset, $len, $advice
1908		2067
1909	Simply calls the C<posix_madvise> function (see its	2068	Simply calls the C<posix_madvise> function (see its
1910	manpage for details). The following advice constants are	2069	manpage for details). The following advice constants are
1911	available: C<IO::AIO::MADV_NORMAL>, C<IO::AIO::MADV_SEQUENTIAL>,	2070	available: C<IO::AIO::MADV_NORMAL>, C<IO::AIO::MADV_SEQUENTIAL>,
1912	C<IO::AIO::MADV_RANDOM>, C<IO::AIO::MADV_WILLNEED>, C<IO::AIO::MADV_DONTNEED>.	2071	C<IO::AIO::MADV_RANDOM>, C<IO::AIO::MADV_WILLNEED>,
		2072	C<IO::AIO::MADV_DONTNEED>.
		2073
		2074	If C<$offset> is negative, counts from the end. If C<$length> is negative,
		2075	the remaining length of the C<$scalar> is used. If possible, C<$length>
		2076	will be reduced to fit into the C<$scalar>.
1913		2077
1914	On systems that do not implement C<posix_madvise>, this function returns	2078	On systems that do not implement C<posix_madvise>, this function returns
1915	ENOSYS, otherwise the return value of C<posix_madvise>.	2079	ENOSYS, otherwise the return value of C<posix_madvise>.
1916		2080
1917	=item IO::AIO::mprotect $scalar, $offset, $len, $protect	2081	=item IO::AIO::mprotect $scalar, $offset, $len, $protect
…		…
1919	Simply calls the C<mprotect> function on the preferably AIO::mmap'ed	2083	Simply calls the C<mprotect> function on the preferably AIO::mmap'ed
1920	$scalar (see its manpage for details). The following protect	2084	$scalar (see its manpage for details). The following protect
1921	constants are available: C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_READ>,	2085	constants are available: C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_READ>,
1922	C<IO::AIO::PROT_WRITE>, C<IO::AIO::PROT_EXEC>.	2086	C<IO::AIO::PROT_WRITE>, C<IO::AIO::PROT_EXEC>.
1923		2087
		2088	If C<$offset> is negative, counts from the end. If C<$length> is negative,
		2089	the remaining length of the C<$scalar> is used. If possible, C<$length>
		2090	will be reduced to fit into the C<$scalar>.
		2091
1924	On systems that do not implement C<mprotect>, this function returns	2092	On systems that do not implement C<mprotect>, this function returns
1925	ENOSYS, otherwise the return value of C<mprotect>.	2093	ENOSYS, otherwise the return value of C<mprotect>.
1926		2094
1927	=item IO::AIO::mmap $scalar, $length, $prot, $flags, $fh[, $offset]	2095	=item IO::AIO::mmap $scalar, $length, $prot, $flags, $fh[, $offset]
1928		2096
1929	Memory-maps a file (or anonymous memory range) and attaches it to the	2097	Memory-maps a file (or anonymous memory range) and attaches it to the
1930	given C<$scalar>, which will act like a string scalar. Returns true on	2098	given C<$scalar>, which will act like a string scalar. Returns true on
1931	success, and false otherwise.	2099	success, and false otherwise.
1932		2100
		2101	The scalar must exist, but its contents do not matter - this means you
		2102	cannot use a nonexistant array or hash element. When in doubt, C<undef>
		2103	the scalar first.
		2104
1933	The only operations allowed on the scalar are C<substr>/C<vec> that don't	2105	The only operations allowed on the mmapped scalar are C<substr>/C<vec>,
1934	change the string length, and most read-only operations such as copying it	2106	which don't change the string length, and most read-only operations such
1935	or searching it with regexes and so on.	2107	as copying it or searching it with regexes and so on.
1936		2108
1937	Anything else is unsafe and will, at best, result in memory leaks.	2109	Anything else is unsafe and will, at best, result in memory leaks.
1938		2110
1939	The memory map associated with the C<$scalar> is automatically removed	2111	The memory map associated with the C<$scalar> is automatically removed
1940	when the C<$scalar> is destroyed, or when the C<IO::AIO::mmap> or	2112	when the C<$scalar> is undef'd or destroyed, or when the C<IO::AIO::mmap>
1941	C<IO::AIO::munmap> functions are called.	2113	or C<IO::AIO::munmap> functions are called on it.
1942		2114
1943	This calls the C<mmap>(2) function internally. See your system's manual	2115	This calls the C<mmap>(2) function internally. See your system's manual
1944	page for details on the C<$length>, C<$prot> and C<$flags> parameters.	2116	page for details on the C<$length>, C<$prot> and C<$flags> parameters.
1945		2117
1946	The C<$length> must be larger than zero and smaller than the actual	2118	The C<$length> must be larger than zero and smaller than the actual
1947	filesize.	2119	filesize.
1948		2120
1949	C<$prot> is a combination of C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_EXEC>,	2121	C<$prot> is a combination of C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_EXEC>,
1950	C<IO::AIO::PROT_READ> and/or C<IO::AIO::PROT_WRITE>,	2122	C<IO::AIO::PROT_READ> and/or C<IO::AIO::PROT_WRITE>,
1951		2123
1952	C<$flags> can be a combination of C<IO::AIO::MAP_SHARED> or	2124	C<$flags> can be a combination of
1953	C<IO::AIO::MAP_PRIVATE>, or a number of system-specific flags (when	2125	C<IO::AIO::MAP_SHARED> or
1954	not available, the are defined as 0): C<IO::AIO::MAP_ANONYMOUS>	2126	C<IO::AIO::MAP_PRIVATE>,
		2127	or a number of system-specific flags (when not available, the are C<0>):
1955	(which is set to C<MAP_ANON> if your system only provides this	2128	C<IO::AIO::MAP_ANONYMOUS> (which is set to C<MAP_ANON> if your system only provides this constant),
1956	constant), C<IO::AIO::MAP_HUGETLB>, C<IO::AIO::MAP_LOCKED>,	2129	C<IO::AIO::MAP_LOCKED>,
1957	C<IO::AIO::MAP_NORESERVE>, C<IO::AIO::MAP_POPULATE> or	2130	C<IO::AIO::MAP_NORESERVE>,
		2131	C<IO::AIO::MAP_POPULATE>,
1958	C<IO::AIO::MAP_NONBLOCK>	2132	C<IO::AIO::MAP_NONBLOCK>,
		2133	C<IO::AIO::MAP_FIXED>,
		2134	C<IO::AIO::MAP_GROWSDOWN>,
		2135	C<IO::AIO::MAP_32BIT>,
		2136	C<IO::AIO::MAP_HUGETLB> or
		2137	C<IO::AIO::MAP_STACK>.
1959		2138
1960	If C<$fh> is C<undef>, then a file descriptor of C<-1> is passed.	2139	If C<$fh> is C<undef>, then a file descriptor of C<-1> is passed.
1961		2140
1962	C<$offset> is the offset from the start of the file - it generally must be	2141	C<$offset> is the offset from the start of the file - it generally must be
1963	a multiple of C<IO::AIO::PAGESIZE> and defaults to C<0>.	2142	a multiple of C<IO::AIO::PAGESIZE> and defaults to C<0>.
…		…
2006		2185
2007	See the C<splice(2)> manpage for details.	2186	See the C<splice(2)> manpage for details.
2008		2187
2009	=item IO::AIO::tee $r_fh, $w_fh, $length, $flags	2188	=item IO::AIO::tee $r_fh, $w_fh, $length, $flags
2010		2189
2011	Calls the GNU/Linux C<tee(2)> syscall, see it's manpage and the	2190	Calls the GNU/Linux C<tee(2)> syscall, see its manpage and the
2012	description for C<IO::AIO::splice> above for details.	2191	description for C<IO::AIO::splice> above for details.
		2192
		2193	=item $actual_size = IO::AIO::pipesize $r_fh[, $new_size]
		2194
		2195	Attempts to query or change the pipe buffer size. Obviously works only
		2196	on pipes, and currently works only on GNU/Linux systems, and fails with
		2197	C<-1>/C<ENOSYS> everywhere else. If anybody knows how to influence pipe buffer
		2198	size on other systems, drop me a note.
		2199
		2200	=item ($rfh, $wfh) = IO::AIO::pipe2 [$flags]
		2201
		2202	This is a direct interface to the Linux L<pipe2(2)> system call. If
		2203	C<$flags> is missing or C<0>, then this should be the same as a call to
		2204	perl's built-in C<pipe> function and create a new pipe, and works on
		2205	systems that lack the pipe2 syscall. On win32, this case invokes C<_pipe
		2206	(..., 4096, O_BINARY)>.
		2207
		2208	If C<$flags> is non-zero, it tries to invoke the pipe2 system call with
		2209	the given flags (Linux 2.6.27, glibc 2.9).
		2210
		2211	On success, the read and write file handles are returned.
		2212
		2213	On error, nothing will be returned. If the pipe2 syscall is missing and
		2214	C<$flags> is non-zero, fails with C<ENOSYS>.
		2215
		2216	Please refer to L<pipe2(2)> for more info on the C<$flags>, but at the
		2217	time of this writing, C<IO::AIO::O_CLOEXEC>, C<IO::AIO::O_NONBLOCK> and
		2218	C<IO::AIO::O_DIRECT> (Linux 3.4, for packet-based pipes) were supported.
2013		2219
2014	=back	2220	=back
2015		2221
2016	=cut	2222	=cut
2017		2223

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Comparing IO-AIO/AIO.pm (file contents): Revision 1.229 by root, Wed Jul 25 16:32:30 2012 UTC vs. Revision 1.280 by root, Mon Feb 19 13:37:13 2018 UTC

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Comparing IO-AIO/AIO.pm (file contents):
Revision 1.229 by root, Wed Jul 25 16:32:30 2012 UTC vs.
Revision 1.280 by root, Mon Feb 19 13:37:13 2018 UTC