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

Comparing IO-AIO/AIO.pm (file contents):
Revision 1.219 by root, Tue Mar 27 18:54:45 2012 UTC vs.
Revision 1.281 by root, Tue Feb 20 04:32:59 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 = '4.12';	176	our $VERSION = 4.4;
174		177
175	our @AIO_REQ = qw(aio_sendfile 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	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)
		218	aio_seek $fh,$offset,$whence, $callback->($offs)
214	aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)	219	aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
215	aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)	220	aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
216	aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval)	221	aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval)
217	aio_readahead $fh,$offset,$length, $callback->($retval)	222	aio_readahead $fh,$offset,$length, $callback->($retval)
218	aio_stat $fh_or_path, $callback->($status)	223	aio_stat $fh_or_path, $callback->($status)
219	aio_lstat $fh, $callback->($status)	224	aio_lstat $fh, $callback->($status)
220	aio_statvfs $fh_or_path, $callback->($statvfs)	225	aio_statvfs $fh_or_path, $callback->($statvfs)
221	aio_utime $fh_or_path, $atime, $mtime, $callback->($status)	226	aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
222	aio_chown $fh_or_path, $uid, $gid, $callback->($status)	227	aio_chown $fh_or_path, $uid, $gid, $callback->($status)
		228	aio_chmod $fh_or_path, $mode, $callback->($status)
223	aio_truncate $fh_or_path, $offset, $callback->($status)	229	aio_truncate $fh_or_path, $offset, $callback->($status)
224	aio_chmod $fh_or_path, $mode, $callback->($status)	230	aio_allocate $fh, $mode, $offset, $len, $callback->($status)
		231	aio_fiemap $fh, $start, $length, $flags, $count, $cb->(\@extents)
225	aio_unlink $pathname, $callback->($status)	232	aio_unlink $pathname, $callback->($status)
226	aio_mknod $pathname, $mode, $dev, $callback->($status)	233	aio_mknod $pathname, $mode, $dev, $callback->($status)
227	aio_link $srcpath, $dstpath, $callback->($status)	234	aio_link $srcpath, $dstpath, $callback->($status)
228	aio_symlink $srcpath, $dstpath, $callback->($status)	235	aio_symlink $srcpath, $dstpath, $callback->($status)
229	aio_readlink $pathname, $callback->($link)	236	aio_readlink $pathname, $callback->($link)
230	aio_realpath $pathname, $callback->($link)	237	aio_realpath $pathname, $callback->($path)
231	aio_rename $srcpath, $dstpath, $callback->($status)	238	aio_rename $srcpath, $dstpath, $callback->($status)
		239	aio_rename2 $srcpath, $dstpath, $flags, $callback->($status)
232	aio_mkdir $pathname, $mode, $callback->($status)	240	aio_mkdir $pathname, $mode, $callback->($status)
233	aio_rmdir $pathname, $callback->($status)	241	aio_rmdir $pathname, $callback->($status)
234	aio_readdir $pathname, $callback->($entries)	242	aio_readdir $pathname, $callback->($entries)
235	aio_readdirx $pathname, $flags, $callback->($entries, $flags)	243	aio_readdirx $pathname, $flags, $callback->($entries, $flags)
236	IO::AIO::READDIR_DENTS IO::AIO::READDIR_DIRS_FIRST	244	IO::AIO::READDIR_DENTS IO::AIO::READDIR_DIRS_FIRST
…		…
238	aio_scandir $pathname, $maxreq, $callback->($dirs, $nondirs)	246	aio_scandir $pathname, $maxreq, $callback->($dirs, $nondirs)
239	aio_load $pathname, $data, $callback->($status)	247	aio_load $pathname, $data, $callback->($status)
240	aio_copy $srcpath, $dstpath, $callback->($status)	248	aio_copy $srcpath, $dstpath, $callback->($status)
241	aio_move $srcpath, $dstpath, $callback->($status)	249	aio_move $srcpath, $dstpath, $callback->($status)
242	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)
243	aio_sync $callback->($status)	253	aio_sync $callback->($status)
244	aio_syncfs $fh, $callback->($status)	254	aio_syncfs $fh, $callback->($status)
245	aio_fsync $fh, $callback->($status)	255	aio_fsync $fh, $callback->($status)
246	aio_fdatasync $fh, $callback->($status)	256	aio_fdatasync $fh, $callback->($status)
247	aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status)	257	aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status)
248	aio_pathsync $pathname, $callback->($status)	258	aio_pathsync $pathname, $callback->($status)
249	aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)	259	aio_msync $scalar, $offset = 0, $length = undef, flags = MS_SYNC, $callback->($status)
250	aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)	260	aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
251	aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status)	261	aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status)
252	aio_mlockall $flags, $callback->($status)	262	aio_mlockall $flags, $callback->($status)
253	aio_group $callback->(...)	263	aio_group $callback->(...)
254	aio_nop $callback->()	264	aio_nop $callback->()
…		…
268	IO::AIO::idle_timeout $seconds	278	IO::AIO::idle_timeout $seconds
269	IO::AIO::max_outstanding $maxreqs	279	IO::AIO::max_outstanding $maxreqs
270	IO::AIO::nreqs	280	IO::AIO::nreqs
271	IO::AIO::nready	281	IO::AIO::nready
272	IO::AIO::npending	282	IO::AIO::npending
		283	$nfd = IO::AIO::get_fdlimit [EXPERIMENTAL]
		284	IO::AIO::min_fdlimit $nfd [EXPERIMENTAL]
273		285
274	IO::AIO::sendfile $ofh, $ifh, $offset, $count	286	IO::AIO::sendfile $ofh, $ifh, $offset, $count
275	IO::AIO::fadvise $fh, $offset, $len, $advice	287	IO::AIO::fadvise $fh, $offset, $len, $advice
		288	IO::AIO::mmap $scalar, $length, $prot, $flags[, $fh[, $offset]]
		289	IO::AIO::munmap $scalar
276	IO::AIO::madvise $scalar, $offset, $length, $advice	290	IO::AIO::madvise $scalar, $offset, $length, $advice
277	IO::AIO::mprotect $scalar, $offset, $length, $protect	291	IO::AIO::mprotect $scalar, $offset, $length, $protect
278	IO::AIO::munlock $scalar, $offset = 0, $length = undef	292	IO::AIO::munlock $scalar, $offset = 0, $length = undef
279	IO::AIO::munlockall	293	IO::AIO::munlockall
280		294
…		…
357		371
358		372
359	=item aio_open $pathname, $flags, $mode, $callback->($fh)	373	=item aio_open $pathname, $flags, $mode, $callback->($fh)
360		374
361	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
362	created filehandle for the file.	376	created filehandle for the file (or C<undef> in case of an error).
363		377
364	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,
365	for an explanation.	379	for an explanation.
366		380
367	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
…		…
390	following POSIX and non-POSIX constants are available (missing ones on	404	following POSIX and non-POSIX constants are available (missing ones on
391	your system are, as usual, C<0>):	405	your system are, as usual, C<0>):
392		406
393	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>,
394	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>,
395	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>.
396		410
397		411
398	=item aio_close $fh, $callback->($status)	412	=item aio_close $fh, $callback->($status)
399		413
400	Asynchronously close a file and call the callback with the result	414	Asynchronously close a file and call the callback with the result
…		…
410	Or in other words: the file descriptor will be closed, but it will not be	424	Or in other words: the file descriptor will be closed, but it will not be
411	free for reuse until the perl filehandle is closed.	425	free for reuse until the perl filehandle is closed.
412		426
413	=cut	427	=cut
414		428
		429	=item aio_seek $fh, $offset, $whence, $callback->($offs)
		430
		431	Seeks the filehandle to the new C<$offset>, similarly to perl's
		432	C<sysseek>. The C<$whence> can use the traditional values (C<0> for
		433	C<IO::AIO::SEEK_SET>, C<1> for C<IO::AIO::SEEK_CUR> or C<2> for
		434	C<IO::AIO::SEEK_END>).
		435
		436	The resulting absolute offset will be passed to the callback, or C<-1> in
		437	case of an error.
		438
		439	In theory, the C<$whence> constants could be different than the
		440	corresponding values from L<Fcntl>, but perl guarantees they are the same,
		441	so don't panic.
		442
		443	As a GNU/Linux (and maybe Solaris) extension, also the constants
		444	C<IO::AIO::SEEK_DATA> and C<IO::AIO::SEEK_HOLE> are available, if they
		445	could be found. No guarantees about suitability for use in C<aio_seek> or
		446	Perl's C<sysseek> can be made though, although I would naively assume they
		447	"just work".
		448
415	=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)	449	=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
416		450
417	=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)	451	=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
418		452
419	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
420	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
421	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
422	error, just like the syscall).	456	error, just like the syscall).
423		457
424	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
425	offset plus the actual number of bytes read.	459	offset plus the actual number of bytes read.
426		460
…		…
484	As native sendfile syscalls (as practically any non-POSIX interface hacked	518	As native sendfile syscalls (as practically any non-POSIX interface hacked
485	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
486	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
487	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,
488	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> -
489	fewre bytes than expected might have been transferred.	523	fewer bytes than expected might have been transferred.
490		524
491		525
492	=item aio_readahead $fh,$offset,$length, $callback->($retval)	526	=item aio_readahead $fh,$offset,$length, $callback->($retval)
493		527
494	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
…		…
498	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
499	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
500	(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
501	file. The current file offset of the file is left unchanged.	535	file. The current file offset of the file is left unchanged.
502		536
503	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
504	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.
505		539
506		540
507	=item aio_stat $fh_or_path, $callback->($status)	541	=item aio_stat $fh_or_path, $callback->($status)
508		542
509	=item aio_lstat $fh, $callback->($status)	543	=item aio_lstat $fh, $callback->($status)
…		…
578	namemax => 255,	612	namemax => 255,
579	frsize => 1024,	613	frsize => 1024,
580	fsid => 1810	614	fsid => 1810
581	}	615	}
582		616
583
584	=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status)	617	=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
585		618
586	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
587	and $mtime being undef). Fractional times are supported if the underlying	620	and $mtime being undef). Fractional times are supported if the underlying
588	syscalls support them.	621	syscalls support them.
…		…
615	=item aio_truncate $fh_or_path, $offset, $callback->($status)	648	=item aio_truncate $fh_or_path, $offset, $callback->($status)
616		649
617	Works like truncate(2) or ftruncate(2).	650	Works like truncate(2) or ftruncate(2).
618		651
619		652
		653	=item aio_allocate $fh, $mode, $offset, $len, $callback->($status)
		654
		655	Allocates or frees disk space according to the C<$mode> argument. See the
		656	linux C<fallocate> documentation for details.
		657
		658	C<$mode> is usually C<0> or C<IO::AIO::FALLOC_FL_KEEP_SIZE> to allocate
		659	space, or C<IO::AIO::FALLOC_FL_PUNCH_HOLE \| IO::AIO::FALLOC_FL_KEEP_SIZE>,
		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).
		666
		667	The file system block size used by C<fallocate> is presumably the
		668	C<f_bsize> returned by C<statvfs>, but different filesystems and filetypes
		669	can dictate other limitations.
		670
		671	If C<fallocate> isn't available or cannot be emulated (currently no
		672	emulation will be attempted), passes C<-1> and sets C<$!> to C<ENOSYS>.
		673
		674
620	=item aio_chmod $fh_or_path, $mode, $callback->($status)	675	=item aio_chmod $fh_or_path, $mode, $callback->($status)
621		676
622	Works like perl's C<chmod> function.	677	Works like perl's C<chmod> function.
623		678
624		679
…		…
661		716
662		717
663	=item aio_realpath $pathname, $callback->($path)	718	=item aio_realpath $pathname, $callback->($path)
664		719
665	Asynchronously make the path absolute and resolve any symlinks in	720	Asynchronously make the path absolute and resolve any symlinks in
666	C<$path>. The resulting path only consists of directories (Same as	721	C<$path>. The resulting path only consists of directories (same as
667	L<Cwd::realpath>).	722	L<Cwd::realpath>).
668		723
669	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
670	directory by passing it a path of F<.> (a single dot).	725	directory by passing it a path of F<.> (a single dot).
671		726
672		727
673	=item aio_rename $srcpath, $dstpath, $callback->($status)	728	=item aio_rename $srcpath, $dstpath, $callback->($status)
674		729
675	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
676	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>.
677		752
678		753
679	=item aio_mkdir $pathname, $mode, $callback->($status)	754	=item aio_mkdir $pathname, $mode, $callback->($status)
680		755
681	Asynchronously mkdir (create) a directory and call the callback with	756	Asynchronously mkdir (create) a directory and call the callback with
…		…
685		760
686	=item aio_rmdir $pathname, $callback->($status)	761	=item aio_rmdir $pathname, $callback->($status)
687		762
688	Asynchronously rmdir (delete) a directory and call the callback with the	763	Asynchronously rmdir (delete) a directory and call the callback with the
689	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>.
690		769
691		770
692	=item aio_readdir $pathname, $callback->($entries)	771	=item aio_readdir $pathname, $callback->($entries)
693		772
694	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
…		…
763	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.
764		843
765	=back	844	=back
766		845
767		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
768	=item aio_load $pathname, $data, $callback->($status)	876	=item aio_load $pathname, $data, $callback->($status)
769		877
770	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
771	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.
772		882
773	=cut	883	=cut
774		884
775	sub aio_load($$;$) {	885	sub aio_load($$;$) {
776	my ($path, undef, $cb) = @_;	886	my ($path, undef, $cb) = @_;
…		…
796	=item aio_copy $srcpath, $dstpath, $callback->($status)	906	=item aio_copy $srcpath, $dstpath, $callback->($status)
797		907
798	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
799	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
800	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.
801		913
802	This is a composite request that creates the destination file with	914	This is a composite request that creates the destination file with
803	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
804	C<aio_sendfile>, followed by restoring atime, mtime, access mode and	916	C<aio_sendfile>, followed by restoring atime, mtime, access mode and
805	uid/gid, in that order.	917	uid/gid, in that order.
…		…
915	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
916	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
917	names, directories you can recurse into (directories), and ones you cannot	1029	names, directories you can recurse into (directories), and ones you cannot
918	recurse into (everything else, including symlinks to directories).	1030	recurse into (everything else, including symlinks to directories).
919		1031
920	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.
921	C<$maxreq> specifies the maximum number of outstanding aio requests that	1033	C<$maxreq> specifies the maximum number of outstanding aio requests that
922	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
923	will be chosen (currently 4).	1035	will be chosen (currently 4).
924		1036
925	On error, the callback is called without arguments, otherwise it receives	1037	On error, the callback is called without arguments, otherwise it receives
…		…
1059	}	1171	}
1060		1172
1061	=item aio_rmtree $pathname, $callback->($status)	1173	=item aio_rmtree $pathname, $callback->($status)
1062		1174
1063	Delete a directory tree starting (and including) C<$path>, return the	1175	Delete a directory tree starting (and including) C<$path>, return the
1064	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
1065	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
1066	everything else.	1178	everything else.
1067		1179
1068	=cut	1180	=cut
1069		1181
…		…
1090	add $grp $dirgrp;	1202	add $grp $dirgrp;
1091	};	1203	};
1092		1204
1093	$grp	1205	$grp
1094	}	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>,
1095		1251
1096	=item aio_sync $callback->($status)	1252	=item aio_sync $callback->($status)
1097		1253
1098	Asynchronously call sync and call the callback when finished.	1254	Asynchronously call sync and call the callback when finished.
1099		1255
…		…
1168	};	1324	};
1169		1325
1170	$grp	1326	$grp
1171	}	1327	}
1172		1328
1173	=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)
1174		1330
1175	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
1176	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
1177	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
1178	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
…		…
1180		1336
1181	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
1182	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
1183	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>
1184	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
1185	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
1186	C<IO::AIO::MS_SYNC>.	1342	C<IO::AIO::MS_INVALIDATE>.
1187		1343
1188	=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)
1189		1345
1190	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
1191	scalars.	1347	scalars.
1192		1348
1193	It touches (reads or writes) all memory pages in the specified	1349	It touches (reads or writes) all memory pages in the specified
1194	range inside the scalar. All caveats and parameters are the same	1350	range inside the scalar. All caveats and parameters are the same
1195	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
1196	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
1197	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
1198	writing an octet from it, which dirties the page).	1354	writing an octet from it, which dirties the page).
1199		1355
1200	=item aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status)	1356	=item aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status)
1201		1357
1202	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
…		…
1233	documented under L<MISCELLANEOUS FUNCTIONS>.	1389	documented under L<MISCELLANEOUS FUNCTIONS>.
1234		1390
1235	Example: asynchronously lock all current and future pages into memory.	1391	Example: asynchronously lock all current and future pages into memory.
1236		1392
1237	aio_mlockall IO::AIO::MCL_FUTURE;	1393	aio_mlockall IO::AIO::MCL_FUTURE;
		1394
		1395	=item aio_fiemap $fh, $start, $length, $flags, $count, $cb->(\@extents)
		1396
		1397	Queries the extents of the given file (by calling the Linux C<FIEMAP>
		1398	ioctl, see L<http://cvs.schmorp.de/IO-AIO/doc/fiemap.txt> for details). If
		1399	the ioctl is not available on your OS, then this request will fail with
		1400	C<ENOSYS>.
		1401
		1402	C<$start> is the starting offset to query extents for, C<$length> is the
		1403	size of the range to query - if it is C<undef>, then the whole file will
		1404	be queried.
		1405
		1406	C<$flags> is a combination of flags (C<IO::AIO::FIEMAP_FLAG_SYNC> or
		1407	C<IO::AIO::FIEMAP_FLAG_XATTR> - C<IO::AIO::FIEMAP_FLAGS_COMPAT> is also
		1408	exported), and is normally C<0> or C<IO::AIO::FIEMAP_FLAG_SYNC> to query
		1409	the data portion.
		1410
		1411	C<$count> is the maximum number of extent records to return. If it is
		1412	C<undef>, then IO::AIO queries all extents of the range. As a very special
		1413	case, if it is C<0>, then the callback receives the number of extents
		1414	instead of the extents themselves (which is unreliable, see below).
		1415
		1416	If an error occurs, the callback receives no arguments. The special
		1417	C<errno> value C<IO::AIO::EBADR> is available to test for flag errors.
		1418
		1419	Otherwise, the callback receives an array reference with extent
		1420	structures. Each extent structure is an array reference itself, with the
		1421	following members:
		1422
		1423	[$logical, $physical, $length, $flags]
		1424
		1425	Flags is any combination of the following flag values (typically either C<0>
		1426	or C<IO::AIO::FIEMAP_EXTENT_LAST> (1)):
		1427
		1428	C<IO::AIO::FIEMAP_EXTENT_LAST>, C<IO::AIO::FIEMAP_EXTENT_UNKNOWN>,
		1429	C<IO::AIO::FIEMAP_EXTENT_DELALLOC>, C<IO::AIO::FIEMAP_EXTENT_ENCODED>,
		1430	C<IO::AIO::FIEMAP_EXTENT_DATA_ENCRYPTED>, C<IO::AIO::FIEMAP_EXTENT_NOT_ALIGNED>,
		1431	C<IO::AIO::FIEMAP_EXTENT_DATA_INLINE>, C<IO::AIO::FIEMAP_EXTENT_DATA_TAIL>,
		1432	C<IO::AIO::FIEMAP_EXTENT_UNWRITTEN>, C<IO::AIO::FIEMAP_EXTENT_MERGED> or
		1433	C<IO::AIO::FIEMAP_EXTENT_SHARED>.
		1434
		1435	At the time of this writing (Linux 3.2), this request is unreliable unless
		1436	C<$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>.
1238		1440
1239	=item aio_group $callback->(...)	1441	=item aio_group $callback->(...)
1240		1442
1241	This is a very special aio request: Instead of doing something, it is a	1443	This is a very special aio request: Instead of doing something, it is a
1242	container for other aio requests, which is useful if you want to bundle	1444	container for other aio requests, which is useful if you want to bundle
…		…
1326	aio_stat [$etcdir, "passwd"], sub {	1528	aio_stat [$etcdir, "passwd"], sub {
1327	# yay	1529	# yay
1328	};	1530	};
1329	};	1531	};
1330		1532
1331	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
1332	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,
1333	why it is done asynchronously.	1535	which is why it is done asynchronously.
1334		1536
1335	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
1336	either of the following three request calls:	1538	either of the following three request calls:
1337		1539
1338	aio_lstat "/etc" , sub { ... # pathname as normal string	1540	aio_lstat "/etc" , sub { ... # pathname as normal string
…		…
1355	There are some caveats: when directories get renamed (or deleted), the	1557	There are some caveats: when directories get renamed (or deleted), the
1356	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
1357	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,
1358	will still point to the original directory. Most functions accepting a	1560	will still point to the original directory. Most functions accepting a
1359	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
1360	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
1361	string form of the pathname.	1563	the string form of the pathname.
1362		1564
1363	So this fucntionality is mainly useful to get some protection against	1565	So this functionality is mainly useful to get some protection against
1364	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
1365	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
1366	(e.g. when stat'ing all files in a directory).	1568	(e.g. when stat'ing all files in a directory).
1367		1569
1368	The following functions implement this working directory abstraction:	1570	The following functions implement this working directory abstraction:
…		…
1381	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
1382	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
1383	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
1384	expected way.	1586	expected way.
1385		1587
1386	If this call isn't available because your OS lacks it or it couldn't be
1387	detected, it will be emulated by calling C<fsync> instead.
1388
1389	=item IO::AIO::CWD	1588	=item IO::AIO::CWD
1390		1589
1391	This is a compiletime constant (object) that represents the process	1590	This is a compiletime constant (object) that represents the process
1392	current working directory.	1591	current working directory.
1393		1592
1394	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
1395	if the pathname would be specified directly, without a directory object,	1594	the pathname would be specified directly, without a directory object. For
1396	e.g., these calls are functionally identical:	1595	example, these calls are functionally identical:
1397		1596
1398	aio_stat "somefile", sub { ... };	1597	aio_stat "somefile", sub { ... };
1399	aio_stat [IO::AIO::CWD, "somefile"], sub { ... };	1598	aio_stat [IO::AIO::CWD, "somefile"], sub { ... };
1400		1599
1401	=back	1600	=back
1402		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.
1403		1611
1404	=head2 IO::AIO::REQ CLASS	1612	=head2 IO::AIO::REQ CLASS
1405		1613
1406	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
1407	called in non-void context.	1615	called in non-void context.
…		…
1585		1793
1586	See C<poll_cb> for an example.	1794	See C<poll_cb> for an example.
1587		1795
1588	=item IO::AIO::poll_cb	1796	=item IO::AIO::poll_cb
1589		1797
1590	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
1591	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
1592	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
1593	reason. Returns immediately when no events are outstanding. The amount of	1804	reason. Returns immediately when no events are outstanding. The amount
1594	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>,
1595	C<IO::AIO::max_poll_time>.	1806	C<IO::AIO::max_poll_time> and C<IO::AIO::max_outstanding>.
1596		1807
1597	If not all requests were processed for whatever reason, the filehandle	1808	If not all requests were processed for whatever reason, the poll file
1598	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
1599	do anything special to have it called later.	1810	don't have to do anything special to have it called later.
1600		1811
1601	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
1602	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
1603	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
1604	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
…		…
1613	poll => 'r', async => 1,	1824	poll => 'r', async => 1,
1614	cb => \&IO::AIO::poll_cb);	1825	cb => \&IO::AIO::poll_cb);
1615		1826
1616	=item IO::AIO::poll_wait	1827	=item IO::AIO::poll_wait
1617		1828
1618	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
1619	phase, wait till the result filehandle becomes ready for reading (simply	1830	requests are outstanding anymore.
1620	does a C<select> on the filehandle. This is useful if you want to	1831
1621	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.
1622		1834
1623	See C<nreqs> for an example.	1835	See C<nreqs> for an example.
1624		1836
1625	=item IO::AIO::poll	1837	=item IO::AIO::poll
1626		1838
…		…
1747		1959
1748	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
1749	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
1750	use an C<aio_group> together with a feed callback.	1962	use an C<aio_group> together with a feed callback.
1751		1963
1752	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
1753	a lot of files, you can write somehting like this:	1965	a lot of files, you can write something like this:
1754		1966
1755	IO::AIO::max_outstanding 32;	1967	IO::AIO::max_outstanding 32;
1756		1968
1757	for my $path (...) {	1969	for my $path (...) {
1758	aio_stat $path , ...;	1970	aio_stat $path , ...;
…		…
1797		2009
1798	=back	2010	=back
1799		2011
1800	=head3 MISCELLANEOUS FUNCTIONS	2012	=head3 MISCELLANEOUS FUNCTIONS
1801		2013
1802	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
1803	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.
1804		2018
1805	=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.
1806		2045
1807	=item IO::AIO::sendfile $ofh, $ifh, $offset, $count	2046	=item IO::AIO::sendfile $ofh, $ifh, $offset, $count
1808		2047
1809	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>,
1810	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
…		…
1827	=item IO::AIO::madvise $scalar, $offset, $len, $advice	2066	=item IO::AIO::madvise $scalar, $offset, $len, $advice
1828		2067
1829	Simply calls the C<posix_madvise> function (see its	2068	Simply calls the C<posix_madvise> function (see its
1830	manpage for details). The following advice constants are	2069	manpage for details). The following advice constants are
1831	available: C<IO::AIO::MADV_NORMAL>, C<IO::AIO::MADV_SEQUENTIAL>,	2070	available: C<IO::AIO::MADV_NORMAL>, C<IO::AIO::MADV_SEQUENTIAL>,
1832	C<IO::AIO::MADV_RANDOM>, C<IO::AIO::MADV_WILLNEED>, C<IO::AIO::MADV_DONTNEED>.	2071	C<IO::AIO::MADV_RANDOM>, C<IO::AIO::MADV_WILLNEED>,
		2072	C<IO::AIO::MADV_DONTNEED>.
		2073
		2074	If C<$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>.
1833		2077
1834	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
1835	ENOSYS, otherwise the return value of C<posix_madvise>.	2079	ENOSYS, otherwise the return value of C<posix_madvise>.
1836		2080
1837	=item IO::AIO::mprotect $scalar, $offset, $len, $protect	2081	=item IO::AIO::mprotect $scalar, $offset, $len, $protect
…		…
1839	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
1840	$scalar (see its manpage for details). The following protect	2084	$scalar (see its manpage for details). The following protect
1841	constants are available: C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_READ>,	2085	constants are available: C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_READ>,
1842	C<IO::AIO::PROT_WRITE>, C<IO::AIO::PROT_EXEC>.	2086	C<IO::AIO::PROT_WRITE>, C<IO::AIO::PROT_EXEC>.
1843		2087
		2088	If C<$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
1844	On systems that do not implement C<mprotect>, this function returns	2092	On systems that do not implement C<mprotect>, this function returns
1845	ENOSYS, otherwise the return value of C<mprotect>.	2093	ENOSYS, otherwise the return value of C<mprotect>.
1846		2094
1847	=item IO::AIO::mmap $scalar, $length, $prot, $flags, $fh[, $offset]	2095	=item IO::AIO::mmap $scalar, $length, $prot, $flags, $fh[, $offset]
1848		2096
1849	Memory-maps a file (or anonymous memory range) and attaches it to the	2097	Memory-maps a file (or anonymous memory range) and attaches it to the
1850	given C<$scalar>, which will act like a string scalar.	2098	given C<$scalar>, which will act like a string scalar. Returns true on
		2099	success, and false otherwise.
1851		2100
		2101	The scalar must exist, but its contents do not matter - this means you
		2102	cannot use a nonexistant array or hash element. When in doubt, C<undef>
		2103	the scalar first.
		2104
1852	The only operations allowed on the scalar are C<substr>/C<vec> that don't	2105	The only operations allowed on the mmapped scalar are C<substr>/C<vec>,
1853	change the string length, and most read-only operations such as copying it	2106	which don't change the string length, and most read-only operations such
1854	or searching it with regexes and so on.	2107	as copying it or searching it with regexes and so on.
1855		2108
1856	Anything else is unsafe and will, at best, result in memory leaks.	2109	Anything else is unsafe and will, at best, result in memory leaks.
1857		2110
1858	The memory map associated with the C<$scalar> is automatically removed	2111	The memory map associated with the C<$scalar> is automatically removed
1859	when the C<$scalar> is destroyed, or when the C<IO::AIO::mmap> or	2112	when the C<$scalar> is undef'd or destroyed, or when the C<IO::AIO::mmap>
1860	C<IO::AIO::munmap> functions are called.	2113	or C<IO::AIO::munmap> functions are called on it.
1861		2114
1862	This calls the C<mmap>(2) function internally. See your system's manual	2115	This calls the C<mmap>(2) function internally. See your system's manual
1863	page for details on the C<$length>, C<$prot> and C<$flags> parameters.	2116	page for details on the C<$length>, C<$prot> and C<$flags> parameters.
1864		2117
1865	The C<$length> must be larger than zero and smaller than the actual	2118	The C<$length> must be larger than zero and smaller than the actual
1866	filesize.	2119	filesize.
1867		2120
1868	C<$prot> is a combination of C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_EXEC>,	2121	C<$prot> is a combination of C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_EXEC>,
1869	C<IO::AIO::PROT_READ> and/or C<IO::AIO::PROT_WRITE>,	2122	C<IO::AIO::PROT_READ> and/or C<IO::AIO::PROT_WRITE>,
1870		2123
1871	C<$flags> can be a combination of C<IO::AIO::MAP_SHARED> or	2124	C<$flags> can be a combination of
1872	C<IO::AIO::MAP_PRIVATE>, or a number of system-specific flags (when	2125	C<IO::AIO::MAP_SHARED> or
1873	not available, the are defined as 0): C<IO::AIO::MAP_ANONYMOUS>	2126	C<IO::AIO::MAP_PRIVATE>,
		2127	or a number of system-specific flags (when not available, the are C<0>):
1874	(which is set to C<MAP_ANON> if your system only provides this	2128	C<IO::AIO::MAP_ANONYMOUS> (which is set to C<MAP_ANON> if your system only provides this constant),
1875	constant), C<IO::AIO::MAP_HUGETLB>, C<IO::AIO::MAP_LOCKED>,	2129	C<IO::AIO::MAP_LOCKED>,
1876	C<IO::AIO::MAP_NORESERVE>, C<IO::AIO::MAP_POPULATE> or	2130	C<IO::AIO::MAP_NORESERVE>,
		2131	C<IO::AIO::MAP_POPULATE>,
1877	C<IO::AIO::MAP_NONBLOCK>	2132	C<IO::AIO::MAP_NONBLOCK>,
		2133	C<IO::AIO::MAP_FIXED>,
		2134	C<IO::AIO::MAP_GROWSDOWN>,
		2135	C<IO::AIO::MAP_32BIT>,
		2136	C<IO::AIO::MAP_HUGETLB> or
		2137	C<IO::AIO::MAP_STACK>.
1878		2138
1879	If C<$fh> is C<undef>, then a file descriptor of C<-1> is passed.	2139	If C<$fh> is C<undef>, then a file descriptor of C<-1> is passed.
1880		2140
1881	C<$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
1882	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>.
…		…
1907		2167
1908	Calls the C<munlockall> function.	2168	Calls the C<munlockall> function.
1909		2169
1910	On systems that do not implement C<munlockall>, this function returns	2170	On systems that do not implement C<munlockall>, this function returns
1911	ENOSYS, otherwise the return value of C<munlockall>.	2171	ENOSYS, otherwise the return value of C<munlockall>.
		2172
		2173	=item IO::AIO::splice $r_fh, $r_off, $w_fh, $w_off, $length, $flags
		2174
		2175	Calls the GNU/Linux C<splice(2)> syscall, if available. If C<$r_off> or
		2176	C<$w_off> are C<undef>, then C<NULL> is passed for these, otherwise they
		2177	should be the file offset.
		2178
		2179	C<$r_fh> and C<$w_fh> should not refer to the same file, as splice might
		2180	silently corrupt the data in this case.
		2181
		2182	The following symbol flag values are available: C<IO::AIO::SPLICE_F_MOVE>,
		2183	C<IO::AIO::SPLICE_F_NONBLOCK>, C<IO::AIO::SPLICE_F_MORE> and
		2184	C<IO::AIO::SPLICE_F_GIFT>.
		2185
		2186	See the C<splice(2)> manpage for details.
		2187
		2188	=item IO::AIO::tee $r_fh, $w_fh, $length, $flags
		2189
		2190	Calls the GNU/Linux C<tee(2)> syscall, see its manpage and the
		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).
1912		2237
1913	=back	2238	=back
1914		2239
1915	=cut	2240	=cut
1916		2241

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Comparing IO-AIO/AIO.pm (file contents): Revision 1.219 by root, Tue Mar 27 18:54:45 2012 UTC vs. Revision 1.281 by root, Tue Feb 20 04:32:59 2018 UTC

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Comparing IO-AIO/AIO.pm (file contents):
Revision 1.219 by root, Tue Mar 27 18:54:45 2012 UTC vs.
Revision 1.281 by root, Tue Feb 20 04:32:59 2018 UTC