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

Comparing IO-AIO/AIO.pm (file contents):
Revision 1.230 by root, Fri Jul 27 17:24:06 2012 UTC vs.
Revision 1.283 by root, Tue Feb 20 06:05:19 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
…		…
228	aio_unlink $pathname, $callback->($status)	232	aio_unlink $pathname, $callback->($status)
229	aio_mknod $pathname, $mode, $dev, $callback->($status)	233	aio_mknod $pathname, $mode, $dev, $callback->($status)
230	aio_link $srcpath, $dstpath, $callback->($status)	234	aio_link $srcpath, $dstpath, $callback->($status)
231	aio_symlink $srcpath, $dstpath, $callback->($status)	235	aio_symlink $srcpath, $dstpath, $callback->($status)
232	aio_readlink $pathname, $callback->($link)	236	aio_readlink $pathname, $callback->($link)
233	aio_realpath $pathname, $callback->($link)	237	aio_realpath $pathname, $callback->($path)
234	aio_rename $srcpath, $dstpath, $callback->($status)	238	aio_rename $srcpath, $dstpath, $callback->($status)
		239	aio_rename2 $srcpath, $dstpath, $flags, $callback->($status)
235	aio_mkdir $pathname, $mode, $callback->($status)	240	aio_mkdir $pathname, $mode, $callback->($status)
236	aio_rmdir $pathname, $callback->($status)	241	aio_rmdir $pathname, $callback->($status)
237	aio_readdir $pathname, $callback->($entries)	242	aio_readdir $pathname, $callback->($entries)
238	aio_readdirx $pathname, $flags, $callback->($entries, $flags)	243	aio_readdirx $pathname, $flags, $callback->($entries, $flags)
239	IO::AIO::READDIR_DENTS IO::AIO::READDIR_DIRS_FIRST	244	IO::AIO::READDIR_DENTS IO::AIO::READDIR_DIRS_FIRST
…		…
241	aio_scandir $pathname, $maxreq, $callback->($dirs, $nondirs)	246	aio_scandir $pathname, $maxreq, $callback->($dirs, $nondirs)
242	aio_load $pathname, $data, $callback->($status)	247	aio_load $pathname, $data, $callback->($status)
243	aio_copy $srcpath, $dstpath, $callback->($status)	248	aio_copy $srcpath, $dstpath, $callback->($status)
244	aio_move $srcpath, $dstpath, $callback->($status)	249	aio_move $srcpath, $dstpath, $callback->($status)
245	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)
246	aio_sync $callback->($status)	253	aio_sync $callback->($status)
247	aio_syncfs $fh, $callback->($status)	254	aio_syncfs $fh, $callback->($status)
248	aio_fsync $fh, $callback->($status)	255	aio_fsync $fh, $callback->($status)
249	aio_fdatasync $fh, $callback->($status)	256	aio_fdatasync $fh, $callback->($status)
250	aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status)	257	aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status)
251	aio_pathsync $pathname, $callback->($status)	258	aio_pathsync $pathname, $callback->($status)
252	aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)	259	aio_msync $scalar, $offset = 0, $length = undef, flags = MS_SYNC, $callback->($status)
253	aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)	260	aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
254	aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status)	261	aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status)
255	aio_mlockall $flags, $callback->($status)	262	aio_mlockall $flags, $callback->($status)
256	aio_group $callback->(...)	263	aio_group $callback->(...)
257	aio_nop $callback->()	264	aio_nop $callback->()
…		…
271	IO::AIO::idle_timeout $seconds	278	IO::AIO::idle_timeout $seconds
272	IO::AIO::max_outstanding $maxreqs	279	IO::AIO::max_outstanding $maxreqs
273	IO::AIO::nreqs	280	IO::AIO::nreqs
274	IO::AIO::nready	281	IO::AIO::nready
275	IO::AIO::npending	282	IO::AIO::npending
		283	$nfd = IO::AIO::get_fdlimit [EXPERIMENTAL]
		284	IO::AIO::min_fdlimit $nfd [EXPERIMENTAL]
276		285
277	IO::AIO::sendfile $ofh, $ifh, $offset, $count	286	IO::AIO::sendfile $ofh, $ifh, $offset, $count
278	IO::AIO::fadvise $fh, $offset, $len, $advice	287	IO::AIO::fadvise $fh, $offset, $len, $advice
279	IO::AIO::mmap $scalar, $length, $prot, $flags[, $fh[, $offset]]	288	IO::AIO::mmap $scalar, $length, $prot, $flags[, $fh[, $offset]]
280	IO::AIO::munmap $scalar	289	IO::AIO::munmap $scalar
…		…
362		371
363		372
364	=item aio_open $pathname, $flags, $mode, $callback->($fh)	373	=item aio_open $pathname, $flags, $mode, $callback->($fh)
365		374
366	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
367	created filehandle for the file.	376	created filehandle for the file (or C<undef> in case of an error).
368		377
369	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,
370	for an explanation.	379	for an explanation.
371		380
372	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
…		…
395	following POSIX and non-POSIX constants are available (missing ones on	404	following POSIX and non-POSIX constants are available (missing ones on
396	your system are, as usual, C<0>):	405	your system are, as usual, C<0>):
397		406
398	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>,
399	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>,
400	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>.
401		410
402		411
403	=item aio_close $fh, $callback->($status)	412	=item aio_close $fh, $callback->($status)
404		413
405	Asynchronously close a file and call the callback with the result	414	Asynchronously close a file and call the callback with the result
…		…
440	=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)	449	=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
441		450
442	=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)	451	=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
443		452
444	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
445	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
446	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
447	error, just like the syscall).	456	error, just like the syscall).
448		457
449	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
450	offset plus the actual number of bytes read.	459	offset plus the actual number of bytes read.
451		460
…		…
509	As native sendfile syscalls (as practically any non-POSIX interface hacked	518	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	519	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	520	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,	521	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> -	522	so you really really should check the return value of C<aio_sendfile> -
514	fewre bytes than expected might have been transferred.	523	fewer bytes than expected might have been transferred.
515		524
516		525
517	=item aio_readahead $fh,$offset,$length, $callback->($retval)	526	=item aio_readahead $fh,$offset,$length, $callback->($retval)
518		527
519	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
…		…
523	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
524	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
525	(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
526	file. The current file offset of the file is left unchanged.	535	file. The current file offset of the file is left unchanged.
527		536
528	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
529	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.
530		539
531		540
532	=item aio_stat $fh_or_path, $callback->($status)	541	=item aio_stat $fh_or_path, $callback->($status)
533		542
534	=item aio_lstat $fh, $callback->($status)	543	=item aio_lstat $fh, $callback->($status)
…		…
603	namemax => 255,	612	namemax => 255,
604	frsize => 1024,	613	frsize => 1024,
605	fsid => 1810	614	fsid => 1810
606	}	615	}
607		616
608
609	=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status)	617	=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
610		618
611	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
612	and $mtime being undef). Fractional times are supported if the underlying	620	and $mtime being undef). Fractional times are supported if the underlying
613	syscalls support them.	621	syscalls support them.
…		…
642	Works like truncate(2) or ftruncate(2).	650	Works like truncate(2) or ftruncate(2).
643		651
644		652
645	=item aio_allocate $fh, $mode, $offset, $len, $callback->($status)	653	=item aio_allocate $fh, $mode, $offset, $len, $callback->($status)
646		654
647	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
648	linux C<fallocate> docuemntation for details.	656	linux C<fallocate> documentation for details.
649		657
650	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
651	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>,
652	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).
653		666
654	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
655	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.
656		670
657	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
658	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>.
659		673
660		674
…		…
702		716
703		717
704	=item aio_realpath $pathname, $callback->($path)	718	=item aio_realpath $pathname, $callback->($path)
705		719
706	Asynchronously make the path absolute and resolve any symlinks in	720	Asynchronously make the path absolute and resolve any symlinks in
707	C<$path>. The resulting path only consists of directories (Same as	721	C<$path>. The resulting path only consists of directories (same as
708	L<Cwd::realpath>).	722	L<Cwd::realpath>).
709		723
710	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
711	directory by passing it a path of F<.> (a single dot).	725	directory by passing it a path of F<.> (a single dot).
712		726
713		727
714	=item aio_rename $srcpath, $dstpath, $callback->($status)	728	=item aio_rename $srcpath, $dstpath, $callback->($status)
715		729
716	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
717	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>.
718		752
719		753
720	=item aio_mkdir $pathname, $mode, $callback->($status)	754	=item aio_mkdir $pathname, $mode, $callback->($status)
721		755
722	Asynchronously mkdir (create) a directory and call the callback with	756	Asynchronously mkdir (create) a directory and call the callback with
…		…
726		760
727	=item aio_rmdir $pathname, $callback->($status)	761	=item aio_rmdir $pathname, $callback->($status)
728		762
729	Asynchronously rmdir (delete) a directory and call the callback with the	763	Asynchronously rmdir (delete) a directory and call the callback with the
730	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>.
731		769
732		770
733	=item aio_readdir $pathname, $callback->($entries)	771	=item aio_readdir $pathname, $callback->($entries)
734		772
735	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
…		…
804	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.
805		843
806	=back	844	=back
807		845
808		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
809	=item aio_load $pathname, $data, $callback->($status)	876	=item aio_load $pathname, $data, $callback->($status)
810		877
811	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
812	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.
813		882
814	=cut	883	=cut
815		884
816	sub aio_load($$;$) {	885	sub aio_load($$;$) {
817	my ($path, undef, $cb) = @_;	886	my ($path, undef, $cb) = @_;
…		…
837	=item aio_copy $srcpath, $dstpath, $callback->($status)	906	=item aio_copy $srcpath, $dstpath, $callback->($status)
838		907
839	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
840	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
841	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.
842		913
843	This is a composite request that creates the destination file with	914	This is a composite request that creates the destination file with
844	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
845	C<aio_sendfile>, followed by restoring atime, mtime, access mode and	916	C<aio_sendfile>, followed by restoring atime, mtime, access mode and
846	uid/gid, in that order.	917	uid/gid, in that order.
…		…
956	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
957	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
958	names, directories you can recurse into (directories), and ones you cannot	1029	names, directories you can recurse into (directories), and ones you cannot
959	recurse into (everything else, including symlinks to directories).	1030	recurse into (everything else, including symlinks to directories).
960		1031
961	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.
962	C<$maxreq> specifies the maximum number of outstanding aio requests that	1033	C<$maxreq> specifies the maximum number of outstanding aio requests that
963	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
964	will be chosen (currently 4).	1035	will be chosen (currently 4).
965		1036
966	On error, the callback is called without arguments, otherwise it receives	1037	On error, the callback is called without arguments, otherwise it receives
…		…
1100	}	1171	}
1101		1172
1102	=item aio_rmtree $pathname, $callback->($status)	1173	=item aio_rmtree $pathname, $callback->($status)
1103		1174
1104	Delete a directory tree starting (and including) C<$path>, return the	1175	Delete a directory tree starting (and including) C<$path>, return the
1105	status of the final C<rmdir> only. This is a composite request that	1176	status of the final C<rmdir> only. This is a composite request that
1106	uses C<aio_scandir> to recurse into and rmdir directories, and unlink	1177	uses C<aio_scandir> to recurse into and rmdir directories, and unlink
1107	everything else.	1178	everything else.
1108		1179
1109	=cut	1180	=cut
1110		1181
…		…
1131	add $grp $dirgrp;	1202	add $grp $dirgrp;
1132	};	1203	};
1133		1204
1134	$grp	1205	$grp
1135	}	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>,
1136		1251
1137	=item aio_sync $callback->($status)	1252	=item aio_sync $callback->($status)
1138		1253
1139	Asynchronously call sync and call the callback when finished.	1254	Asynchronously call sync and call the callback when finished.
1140		1255
…		…
1209	};	1324	};
1210		1325
1211	$grp	1326	$grp
1212	}	1327	}
1213		1328
1214	=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)
1215		1330
1216	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
1217	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
1218	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
1219	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
…		…
1221		1336
1222	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
1223	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
1224	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>
1225	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
1226	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
1227	C<IO::AIO::MS_SYNC>.	1342	C<IO::AIO::MS_INVALIDATE>.
1228		1343
1229	=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)
1230		1345
1231	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
1232	scalars.	1347	scalars.
1233		1348
1234	It touches (reads or writes) all memory pages in the specified	1349	It touches (reads or writes) all memory pages in the specified
1235	range inside the scalar. All caveats and parameters are the same	1350	range inside the scalar. All caveats and parameters are the same
1236	as for C<aio_msync>, above, except for flags, which must be either	1351	as for C<aio_msync>, above, except for flags, which must be either
1237	C<0> (which reads all pages and ensures they are instantiated) or	1352	C<0> (which reads all pages and ensures they are instantiated) or
1238	C<IO::AIO::MT_MODIFY>, which modifies the memory page s(by reading and	1353	C<IO::AIO::MT_MODIFY>, which modifies the memory pages (by reading and
1239	writing an octet from it, which dirties the page).	1354	writing an octet from it, which dirties the page).
1240		1355
1241	=item aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status)	1356	=item aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status)
1242		1357
1243	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
…		…
1277		1392
1278	aio_mlockall IO::AIO::MCL_FUTURE;	1393	aio_mlockall IO::AIO::MCL_FUTURE;
1279		1394
1280	=item aio_fiemap $fh, $start, $length, $flags, $count, $cb->(\@extents)	1395	=item aio_fiemap $fh, $start, $length, $flags, $count, $cb->(\@extents)
1281		1396
1282	Queries the extents of the given file (by calling the Linux FIEMAP ioctl,	1397	Queries the extents of the given file (by calling the Linux C<FIEMAP>
1283	see L<http://cvs.schmorp.de/IO-AIO/doc/fiemap.txt> for details). If the	1398	ioctl, see L<http://cvs.schmorp.de/IO-AIO/doc/fiemap.txt> for details). If
1284	C<ioctl> is not available on your OS, then this request will fail with	1399	the ioctl is not available on your OS, then this request will fail with
1285	C<ENOSYS>.	1400	C<ENOSYS>.
1286		1401
1287	C<$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<$length> is the
1288	size of the range to query - if it is C<undef>, then the whole file will	1403	size of the range to query - if it is C<undef>, then the whole file will
1289	be queried.	1404	be queried.
…		…
1292	C<IO::AIO::FIEMAP_FLAG_XATTR> - C<IO::AIO::FIEMAP_FLAGS_COMPAT> is also	1407	C<IO::AIO::FIEMAP_FLAG_XATTR> - C<IO::AIO::FIEMAP_FLAGS_COMPAT> is also
1293	exported), and is normally C<0> or C<IO::AIO::FIEMAP_FLAG_SYNC> to query	1408	exported), and is normally C<0> or C<IO::AIO::FIEMAP_FLAG_SYNC> to query
1294	the data portion.	1409	the data portion.
1295		1410
1296	C<$count> is the maximum number of extent records to return. If it is	1411	C<$count> is the maximum number of extent records to return. If it is
1297	C<undef>, then IO::AIO queries all extents of the file. As a very special	1412	C<undef>, then IO::AIO queries all extents of the range. As a very special
1298	case, if it is C<0>, then the callback receives the number of extents	1413	case, if it is C<0>, then the callback receives the number of extents
1299	instead of the extents themselves.	1414	instead of the extents themselves (which is unreliable, see below).
1300		1415
1301	If an error occurs, the callback receives no arguments. The special	1416	If an error occurs, the callback receives no arguments. The special
1302	C<errno> value C<IO::AIO::EBADR> is available to test for flag errors.	1417	C<errno> value C<IO::AIO::EBADR> is available to test for flag errors.
1303		1418
1304	Otherwise, the callback receives an array reference with extent	1419	Otherwise, the callback receives an array reference with extent
…		…
1306	following members:	1421	following members:
1307		1422
1308	[$logical, $physical, $length, $flags]	1423	[$logical, $physical, $length, $flags]
1309		1424
1310	Flags is any combination of the following flag values (typically either C<0>	1425	Flags is any combination of the following flag values (typically either C<0>
1311	or C<IO::AIO::FIEMAP_EXTENT_LAST>):	1426	or C<IO::AIO::FIEMAP_EXTENT_LAST> (1)):
1312		1427
1313	C<IO::AIO::FIEMAP_EXTENT_LAST>, C<IO::AIO::FIEMAP_EXTENT_UNKNOWN>,	1428	C<IO::AIO::FIEMAP_EXTENT_LAST>, C<IO::AIO::FIEMAP_EXTENT_UNKNOWN>,
1314	C<IO::AIO::FIEMAP_EXTENT_DELALLOC>, C<IO::AIO::FIEMAP_EXTENT_ENCODED>,	1429	C<IO::AIO::FIEMAP_EXTENT_DELALLOC>, C<IO::AIO::FIEMAP_EXTENT_ENCODED>,
1315	C<IO::AIO::FIEMAP_EXTENT_DATA_ENCRYPTED>, C<IO::AIO::FIEMAP_EXTENT_NOT_ALIGNED>,	1430	C<IO::AIO::FIEMAP_EXTENT_DATA_ENCRYPTED>, C<IO::AIO::FIEMAP_EXTENT_NOT_ALIGNED>,
1316	C<IO::AIO::FIEMAP_EXTENT_DATA_INLINE>, C<IO::AIO::FIEMAP_EXTENT_DATA_TAIL>,	1431	C<IO::AIO::FIEMAP_EXTENT_DATA_INLINE>, C<IO::AIO::FIEMAP_EXTENT_DATA_TAIL>,
1317	C<IO::AIO::FIEMAP_EXTENT_UNWRITTEN>, C<IO::AIO::FIEMAP_EXTENT_MERGED> or	1432	C<IO::AIO::FIEMAP_EXTENT_UNWRITTEN>, C<IO::AIO::FIEMAP_EXTENT_MERGED> or
1318	C<IO::AIO::FIEMAP_EXTENT_SHARED>.	1433	C<IO::AIO::FIEMAP_EXTENT_SHARED>.
1319		1434
		1435	At the time of this writing (Linux 3.2), this request is unreliable unless
		1436	C<$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
1320	=item aio_group $callback->(...)	1441	=item aio_group $callback->(...)
1321		1442
1322	This is a very special aio request: Instead of doing something, it is a	1443	This is a very special aio request: Instead of doing something, it is a
1323	container for other aio requests, which is useful if you want to bundle	1444	container for other aio requests, which is useful if you want to bundle
1324	many requests into a single, composite, request with a definite callback	1445	many requests into a single, composite, request with a definite callback
…		…
1407	aio_stat [$etcdir, "passwd"], sub {	1528	aio_stat [$etcdir, "passwd"], sub {
1408	# yay	1529	# yay
1409	};	1530	};
1410	};	1531	};
1411		1532
1412	That C<aio_wd> is a request and not a normal function shows that creating	1533	The fact that C<aio_wd> is a request and not a normal function shows that
1413	an IO::AIO::WD object is itself a potentially blocking operation, which is	1534	creating an IO::AIO::WD object is itself a potentially blocking operation,
1414	why it is done asynchronously.	1535	which is why it is done asynchronously.
1415		1536
1416	To stat the directory obtained with C<aio_wd> above, one could write	1537	To stat the directory obtained with C<aio_wd> above, one could write
1417	either of the following three request calls:	1538	either of the following three request calls:
1418		1539
1419	aio_lstat "/etc" , sub { ... # pathname as normal string	1540	aio_lstat "/etc" , sub { ... # pathname as normal string
…		…
1436	There are some caveats: when directories get renamed (or deleted), the	1557	There are some caveats: when directories get renamed (or deleted), the
1437	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
1438	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,
1439	will still point to the original directory. Most functions accepting a	1560	will still point to the original directory. Most functions accepting a
1440	pathname will use the directory fd on newer systems, and the string on	1561	pathname will use the directory fd on newer systems, and the string on
1441	older systems. Some functions (such as realpath) will always rely on the	1562	older systems. Some functions (such as C<aio_realpath>) will always rely on
1442	string form of the pathname.	1563	the string form of the pathname.
1443		1564
1444	So this fucntionality is mainly useful to get some protection against	1565	So this functionality is mainly useful to get some protection against
1445	C<chdir>, to easily get an absolute path out of a relative path for future	1566	C<chdir>, to easily get an absolute path out of a relative path for future
1446	reference, and to speed up doing many operations in the same directory	1567	reference, and to speed up doing many operations in the same directory
1447	(e.g. when stat'ing all files in a directory).	1568	(e.g. when stat'ing all files in a directory).
1448		1569
1449	The following functions implement this working directory abstraction:	1570	The following functions implement this working directory abstraction:
…		…
1462	passing C<undef> as working directory component of a pathname fails the	1583	passing C<undef> as working directory component of a pathname fails the
1463	request with C<ENOENT>, there is often no need for error checking in the	1584	request with C<ENOENT>, there is often no need for error checking in the
1464	C<aio_wd> callback, as future requests using the value will fail in the	1585	C<aio_wd> callback, as future requests using the value will fail in the
1465	expected way.	1586	expected way.
1466		1587
1467	If this call isn't available because your OS lacks it or it couldn't be
1468	detected, it will be emulated by calling C<fsync> instead.
1469
1470	=item IO::AIO::CWD	1588	=item IO::AIO::CWD
1471		1589
1472	This is a compiletime constant (object) that represents the process	1590	This is a compiletime constant (object) that represents the process
1473	current working directory.	1591	current working directory.
1474		1592
1475	Specifying this object as working directory object for a pathname is as	1593	Specifying this object as working directory object for a pathname is as if
1476	if the pathname would be specified directly, without a directory object,	1594	the pathname would be specified directly, without a directory object. For
1477	e.g., these calls are functionally identical:	1595	example, these calls are functionally identical:
1478		1596
1479	aio_stat "somefile", sub { ... };	1597	aio_stat "somefile", sub { ... };
1480	aio_stat [IO::AIO::CWD, "somefile"], sub { ... };	1598	aio_stat [IO::AIO::CWD, "somefile"], sub { ... };
1481		1599
1482	=back	1600	=back
1483		1601
		1602	To recover the path associated with an IO::AIO::WD object, you can use
		1603	C<aio_realpath>:
		1604
		1605	aio_realpath $wd, sub {
		1606	warn "path is $_[0]\n";
		1607	};
		1608
		1609	Currently, C<aio_statvfs> always, and C<aio_rename> and C<aio_rmdir>
		1610	sometimes, fall back to using an absolue path.
1484		1611
1485	=head2 IO::AIO::REQ CLASS	1612	=head2 IO::AIO::REQ CLASS
1486		1613
1487	All non-aggregate C<aio_*> functions return an object of this class when	1614	All non-aggregate C<aio_*> functions return an object of this class when
1488	called in non-void context.	1615	called in non-void context.
…		…
1666		1793
1667	See C<poll_cb> for an example.	1794	See C<poll_cb> for an example.
1668		1795
1669	=item IO::AIO::poll_cb	1796	=item IO::AIO::poll_cb
1670		1797
1671	Process some outstanding events on the result pipe. You have to call	1798	Process some requests that have reached the result phase (i.e. they have
		1799	been executed but the results are not yet reported). You have to call
		1800	this "regularly" to finish outstanding requests.
		1801
1672	this regularly. Returns C<0> if all events could be processed (or there	1802	Returns C<0> if all events could be processed (or there were no
1673	were no events to process), or C<-1> if it returned earlier for whatever	1803	events to process), or C<-1> if it returned earlier for whatever
1674	reason. Returns immediately when no events are outstanding. The amount of	1804	reason. Returns immediately when no events are outstanding. The amount
1675	events processed depends on the settings of C<IO::AIO::max_poll_req> and	1805	of events processed depends on the settings of C<IO::AIO::max_poll_req>,
1676	C<IO::AIO::max_poll_time>.	1806	C<IO::AIO::max_poll_time> and C<IO::AIO::max_outstanding>.
1677		1807
1678	If not all requests were processed for whatever reason, the filehandle	1808	If not all requests were processed for whatever reason, the poll file
1679	will still be ready when C<poll_cb> returns, so normally you don't have to	1809	descriptor will still be ready when C<poll_cb> returns, so normally you
1680	do anything special to have it called later.	1810	don't have to do anything special to have it called later.
1681		1811
1682	Apart from calling C<IO::AIO::poll_cb> when the event filehandle becomes	1812	Apart from calling C<IO::AIO::poll_cb> when the event filehandle becomes
1683	ready, it can be beneficial to call this function from loops which submit	1813	ready, it can be beneficial to call this function from loops which submit
1684	a lot of requests, to make sure the results get processed when they become	1814	a lot of requests, to make sure the results get processed when they become
1685	available and not just when the loop is finished and the event loop takes	1815	available and not just when the loop is finished and the event loop takes
…		…
1694	poll => 'r', async => 1,	1824	poll => 'r', async => 1,
1695	cb => \&IO::AIO::poll_cb);	1825	cb => \&IO::AIO::poll_cb);
1696		1826
1697	=item IO::AIO::poll_wait	1827	=item IO::AIO::poll_wait
1698		1828
1699	If there are any outstanding requests and none of them in the result	1829	Wait until either at least one request is in the result phase or no
1700	phase, wait till the result filehandle becomes ready for reading (simply	1830	requests are outstanding anymore.
1701	does a C<select> on the filehandle. This is useful if you want to	1831
1702	synchronously wait for some requests to finish).	1832	This is useful if you want to synchronously wait for some requests to
		1833	become ready, without actually handling them.
1703		1834
1704	See C<nreqs> for an example.	1835	See C<nreqs> for an example.
1705		1836
1706	=item IO::AIO::poll	1837	=item IO::AIO::poll
1707		1838
…		…
1828		1959
1829	This is a very bad function to use in interactive programs because it	1960	This is a very bad function to use in interactive programs because it
1830	blocks, and a bad way to reduce concurrency because it is inexact: Better	1961	blocks, and a bad way to reduce concurrency because it is inexact: Better
1831	use an C<aio_group> together with a feed callback.	1962	use an C<aio_group> together with a feed callback.
1832		1963
1833	It's main use is in scripts without an event loop - when you want to stat	1964	Its main use is in scripts without an event loop - when you want to stat
1834	a lot of files, you can write somehting like this:	1965	a lot of files, you can write something like this:
1835		1966
1836	IO::AIO::max_outstanding 32;	1967	IO::AIO::max_outstanding 32;
1837		1968
1838	for my $path (...) {	1969	for my $path (...) {
1839	aio_stat $path , ...;	1970	aio_stat $path , ...;
…		…
1878		2009
1879	=back	2010	=back
1880		2011
1881	=head3 MISCELLANEOUS FUNCTIONS	2012	=head3 MISCELLANEOUS FUNCTIONS
1882		2013
1883	IO::AIO implements some functions that might be useful, but are not	2014	IO::AIO implements some functions that are useful when you want to use
1884	asynchronous.	2015	some "Advanced I/O" function not available to in Perl, without going the
		2016	"Asynchronous I/O" route. Many of these have an asynchronous C<aio_*>
		2017	counterpart.
1885		2018
1886	=over 4	2019	=over 4
		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.
1887		2045
1888	=item IO::AIO::sendfile $ofh, $ifh, $offset, $count	2046	=item IO::AIO::sendfile $ofh, $ifh, $offset, $count
1889		2047
1890	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>,
1891	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
…		…
1908	=item IO::AIO::madvise $scalar, $offset, $len, $advice	2066	=item IO::AIO::madvise $scalar, $offset, $len, $advice
1909		2067
1910	Simply calls the C<posix_madvise> function (see its	2068	Simply calls the C<posix_madvise> function (see its
1911	manpage for details). The following advice constants are	2069	manpage for details). The following advice constants are
1912	available: C<IO::AIO::MADV_NORMAL>, C<IO::AIO::MADV_SEQUENTIAL>,	2070	available: C<IO::AIO::MADV_NORMAL>, C<IO::AIO::MADV_SEQUENTIAL>,
1913	C<IO::AIO::MADV_RANDOM>, C<IO::AIO::MADV_WILLNEED>, C<IO::AIO::MADV_DONTNEED>.	2071	C<IO::AIO::MADV_RANDOM>, C<IO::AIO::MADV_WILLNEED>,
		2072	C<IO::AIO::MADV_DONTNEED>.
		2073
		2074	If C<$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>.
1914		2077
1915	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
1916	ENOSYS, otherwise the return value of C<posix_madvise>.	2079	ENOSYS, otherwise the return value of C<posix_madvise>.
1917		2080
1918	=item IO::AIO::mprotect $scalar, $offset, $len, $protect	2081	=item IO::AIO::mprotect $scalar, $offset, $len, $protect
…		…
1920	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
1921	$scalar (see its manpage for details). The following protect	2084	$scalar (see its manpage for details). The following protect
1922	constants are available: C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_READ>,	2085	constants are available: C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_READ>,
1923	C<IO::AIO::PROT_WRITE>, C<IO::AIO::PROT_EXEC>.	2086	C<IO::AIO::PROT_WRITE>, C<IO::AIO::PROT_EXEC>.
1924		2087
		2088	If C<$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
1925	On systems that do not implement C<mprotect>, this function returns	2092	On systems that do not implement C<mprotect>, this function returns
1926	ENOSYS, otherwise the return value of C<mprotect>.	2093	ENOSYS, otherwise the return value of C<mprotect>.
1927		2094
1928	=item IO::AIO::mmap $scalar, $length, $prot, $flags, $fh[, $offset]	2095	=item IO::AIO::mmap $scalar, $length, $prot, $flags, $fh[, $offset]
1929		2096
1930	Memory-maps a file (or anonymous memory range) and attaches it to the	2097	Memory-maps a file (or anonymous memory range) and attaches it to the
1931	given C<$scalar>, which will act like a string scalar. Returns true on	2098	given C<$scalar>, which will act like a string scalar. Returns true on
1932	success, and false otherwise.	2099	success, and false otherwise.
1933		2100
		2101	The scalar must exist, but its contents do not matter - this means you
		2102	cannot use a nonexistant array or hash element. When in doubt, C<undef>
		2103	the scalar first.
		2104
1934	The only operations allowed on the scalar are C<substr>/C<vec> that don't	2105	The only operations allowed on the mmapped scalar are C<substr>/C<vec>,
1935	change the string length, and most read-only operations such as copying it	2106	which don't change the string length, and most read-only operations such
1936	or searching it with regexes and so on.	2107	as copying it or searching it with regexes and so on.
1937		2108
1938	Anything else is unsafe and will, at best, result in memory leaks.	2109	Anything else is unsafe and will, at best, result in memory leaks.
1939		2110
1940	The memory map associated with the C<$scalar> is automatically removed	2111	The memory map associated with the C<$scalar> is automatically removed
1941	when the C<$scalar> is destroyed, or when the C<IO::AIO::mmap> or	2112	when the C<$scalar> is undef'd or destroyed, or when the C<IO::AIO::mmap>
1942	C<IO::AIO::munmap> functions are called.	2113	or C<IO::AIO::munmap> functions are called on it.
1943		2114
1944	This calls the C<mmap>(2) function internally. See your system's manual	2115	This calls the C<mmap>(2) function internally. See your system's manual
1945	page for details on the C<$length>, C<$prot> and C<$flags> parameters.	2116	page for details on the C<$length>, C<$prot> and C<$flags> parameters.
1946		2117
1947	The C<$length> must be larger than zero and smaller than the actual	2118	The C<$length> must be larger than zero and smaller than the actual
1948	filesize.	2119	filesize.
1949		2120
1950	C<$prot> is a combination of C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_EXEC>,	2121	C<$prot> is a combination of C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_EXEC>,
1951	C<IO::AIO::PROT_READ> and/or C<IO::AIO::PROT_WRITE>,	2122	C<IO::AIO::PROT_READ> and/or C<IO::AIO::PROT_WRITE>,
1952		2123
1953	C<$flags> can be a combination of C<IO::AIO::MAP_SHARED> or	2124	C<$flags> can be a combination of
1954	C<IO::AIO::MAP_PRIVATE>, or a number of system-specific flags (when	2125	C<IO::AIO::MAP_SHARED> or
1955	not available, the are defined as 0): C<IO::AIO::MAP_ANONYMOUS>	2126	C<IO::AIO::MAP_PRIVATE>,
		2127	or a number of system-specific flags (when not available, the are C<0>):
1956	(which is set to C<MAP_ANON> if your system only provides this	2128	C<IO::AIO::MAP_ANONYMOUS> (which is set to C<MAP_ANON> if your system only provides this constant),
1957	constant), C<IO::AIO::MAP_HUGETLB>, C<IO::AIO::MAP_LOCKED>,	2129	C<IO::AIO::MAP_LOCKED>,
1958	C<IO::AIO::MAP_NORESERVE>, C<IO::AIO::MAP_POPULATE> or	2130	C<IO::AIO::MAP_NORESERVE>,
		2131	C<IO::AIO::MAP_POPULATE>,
1959	C<IO::AIO::MAP_NONBLOCK>	2132	C<IO::AIO::MAP_NONBLOCK>,
		2133	C<IO::AIO::MAP_FIXED>,
		2134	C<IO::AIO::MAP_GROWSDOWN>,
		2135	C<IO::AIO::MAP_32BIT>,
		2136	C<IO::AIO::MAP_HUGETLB> or
		2137	C<IO::AIO::MAP_STACK>.
1960		2138
1961	If C<$fh> is C<undef>, then a file descriptor of C<-1> is passed.	2139	If C<$fh> is C<undef>, then a file descriptor of C<-1> is passed.
1962		2140
1963	C<$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
1964	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>.
…		…
2007		2185
2008	See the C<splice(2)> manpage for details.	2186	See the C<splice(2)> manpage for details.
2009		2187
2010	=item IO::AIO::tee $r_fh, $w_fh, $length, $flags	2188	=item IO::AIO::tee $r_fh, $w_fh, $length, $flags
2011		2189
2012	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
2013	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.
		2219
		2220	Example: create a pipe race-free w.r.t. threads and fork:
		2221
		2222	my ($rfh, $wfh) = IO::AIO::pipe2 IO::AIO::O_CLOEXEC
		2223	or die "pipe2: $!\n";
		2224
		2225	=item $fh = IO::AIO::eventfd [$initval, [$flags]]
		2226
		2227	This is a direct interface to the Linux L<eventfd(2)> system call. The
		2228	(unhelpful) defaults for C<$initval> and C<$flags> are C<0> for both.
		2229
		2230	On success, the new eventfd filehandle is returned, otherwise returns
		2231	C<undef>. If the eventfd syscall is missing, fails with C<ENOSYS>.
		2232
		2233	Please refer to L<eventfd(2)> for more info on this call.
		2234
		2235	The following symbol flag values are available: C<IO::AIO::EFD_CLOEXEC>,
		2236	C<IO::AIO::EFD_NONBLOCK> and C<IO::AIO::EFD_SEMAPHORE> (Linux 2.6.30).
		2237
		2238	Example: create a new eventfd filehandle:
		2239
		2240	$fh = IO::AIO::eventfd 0, IO::AIO::O_CLOEXEC
		2241	or die "eventfd: $!\n";
		2242
		2243	=item $fh = IO::AIO::timerfd_create $clockid[, $flags]
		2244
		2245	This is a direct interface to the Linux L<timerfd_create(2)> system call. The
		2246	(unhelpful) default for C<$flags> is C<0>.
		2247
		2248	On success, the new timerfd filehandle is returned, otherwise returns
		2249	C<undef>. If the eventfd syscall is missing, fails with C<ENOSYS>.
		2250
		2251	Please refer to L<timerfd_create(2)> for more info on this call.
		2252
		2253	The following C<$clockid> values are
		2254	available: C<IO::AIO::CLOCK_REALTIME>, C<IO::AIO::CLOCK_MONOTONIC>
		2255	C<IO::AIO::CLOCK_CLOCK_BOOTTIME> (Linux 3.15)
		2256	C<IO::AIO::CLOCK_CLOCK_REALTIME_ALARM> (Linux 3.11) and
		2257	C<IO::AIO::CLOCK_CLOCK_BOOTTIME_ALARM> (Linux 3.11).
		2258
		2259	The following C<$flags> values are available (Linux
		2260	2.6.27): C<IO::AIO::TFD_NONBLOCK> and C<IO::AIO::TFD_CLOEXEC>.
		2261
		2262	Example: create a new timerfd and set it to one-second repeated alarms,
		2263	then wait for two alarms:
		2264
		2265	my $fh = IO::AIO::timerfd_create IO::AIO::CLOCK_BOOTTIME, IO::AIO::TFD_CLOEXEC
		2266	or die "timerfd_create: $!\n";
		2267
		2268	defined IO::AIO::timerfd_settime $fh, 0, 1, 1
		2269	or die "timerfd_settime: $!\n";
		2270
		2271	for (1..2) {
		2272	8 == sysread $fh, my $buf, 8
		2273	or die "timerfd read failure\n";
		2274
		2275	printf "number of expirations (likely 1): %d\n",
		2276	unpack "Q", $buf;
		2277	}
		2278
		2279	=item ($cur_interval, $cur_value) = IO::AIO::timerfd_settime $fh, $flags, $new_interval, $nbw_value
		2280
		2281	This is a direct interface to the Linux L<timerfd_settime(2)> system
		2282	call. Please refer to its manpage for more info on this call.
		2283
		2284	The new itimerspec is specified using two (possibly fractional) second
		2285	values, C<$new_interval> and C<$new_value>).
		2286
		2287	On success, the current interval and value are returned (as per
		2288	C<timerfd_gettime>). On failure, the empty list is returned.
		2289
		2290	The following C<$flags> values are
		2291	available: C<IO::AIO::TFD_TIMER_ABSTIME> and
		2292	C<IO::AIO::TFD_TIMER_CANCEL_ON_SET>.
		2293
		2294	See C<IO::AIO::timerfd_create> for a full example.
		2295
		2296	=item ($cur_interval, $cur_value) = IO::AIO::timerfd_gettime $fh
		2297
		2298	This is a direct interface to the Linux L<timerfd_gettime(2)> system
		2299	call. Please refer to its manpage for more info on this call.
		2300
		2301	On success, returns the current values of interval and value for the given
		2302	timerfd (as potentially fractional second values). On failure, the empty
		2303	list is returned.
2014		2304
2015	=back	2305	=back
2016		2306
2017	=cut	2307	=cut
2018		2308
…		…
2084	the process will result in undefined behaviour. Calling it at any time	2374	the process will result in undefined behaviour. Calling it at any time
2085	will also result in any undefined (by POSIX) behaviour.	2375	will also result in any undefined (by POSIX) behaviour.
2086		2376
2087	=back	2377	=back
2088		2378
		2379	=head2 LINUX-SPECIFIC CALLS
		2380
		2381	When a call is documented as "linux-specific" then this means it
		2382	originated on GNU/Linux. C<IO::AIO> will usually try to autodetect the
		2383	availability and compatibility of such calls regardless of the platform
		2384	it is compiled on, so platforms such as FreeBSD which often implement
		2385	these calls will work. When in doubt, call them and see if they fail wth
		2386	C<ENOSYS>.
		2387
2089	=head2 MEMORY USAGE	2388	=head2 MEMORY USAGE
2090		2389
2091	Per-request usage:	2390	Per-request usage:
2092		2391
2093	Each aio request uses - depending on your architecture - around 100-200	2392	Each aio request uses - depending on your architecture - around 100-200
…		…
2105	temporary buffers, and each thread requires a stack and other data	2404	temporary buffers, and each thread requires a stack and other data
2106	structures (usually around 16k-128k, depending on the OS).	2405	structures (usually around 16k-128k, depending on the OS).
2107		2406
2108	=head1 KNOWN BUGS	2407	=head1 KNOWN BUGS
2109		2408
2110	Known bugs will be fixed in the next release.	2409	Known bugs will be fixed in the next release :)
		2410
		2411	=head1 KNOWN ISSUES
		2412
		2413	Calls that try to "import" foreign memory areas (such as C<IO::AIO::mmap>
		2414	or C<IO::AIO::aio_slurp>) do not work with generic lvalues, such as
		2415	non-created hash slots or other scalars I didn't think of. It's best to
		2416	avoid such and either use scalar variables or making sure that the scalar
		2417	exists (e.g. by storing C<undef>) and isn't "funny" (e.g. tied).
		2418
		2419	I am not sure anything can be done about this, so this is considered a
		2420	known issue, rather than a bug.
2111		2421
2112	=head1 SEE ALSO	2422	=head1 SEE ALSO
2113		2423
2114	L<AnyEvent::AIO> for easy integration into event loops, L<Coro::AIO> for a	2424	L<AnyEvent::AIO> for easy integration into event loops, L<Coro::AIO> for a
2115	more natural syntax.	2425	more natural syntax.

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Comparing IO-AIO/AIO.pm (file contents): Revision 1.230 by root, Fri Jul 27 17:24:06 2012 UTC vs. Revision 1.283 by root, Tue Feb 20 06:05:19 2018 UTC

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Comparing IO-AIO/AIO.pm (file contents):
Revision 1.230 by root, Fri Jul 27 17:24:06 2012 UTC vs.
Revision 1.283 by root, Tue Feb 20 06:05:19 2018 UTC