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

Comparing IO-AIO/AIO.pm (file contents):
Revision 1.204 by root, Mon Jul 18 02:02:26 2011 UTC vs.
Revision 1.278 by root, Sun Oct 1 07:24:34 2017 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 = '3.93';	176	our $VERSION = 4.35;
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 aio_fsync	180	aio_scandir aio_symlink aio_readlink aio_realpath aio_fcntl aio_ioctl
178	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_wd);
185		189
186	our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice));	190	our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice));
187	our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush	191	our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush
188	min_parallel max_parallel max_idle idle_timeout	192	min_parallel max_parallel max_idle idle_timeout
189	nreqs nready npending nthreads	193	nreqs nready npending nthreads
…		…
201		205
202	=head1 FUNCTIONS	206	=head1 FUNCTIONS
203		207
204	=head2 QUICK OVERVIEW	208	=head2 QUICK OVERVIEW
205		209
206	This section simply lists the prototypes of the most important functions	210	This section simply lists the prototypes most of the functions for
207	for quick reference. See the following sections for function-by-function	211	quick reference. See the following sections for function-by-function
208	documentation.	212	documentation.
209		213
		214	aio_wd $pathname, $callback->($wd)
210	aio_open $pathname, $flags, $mode, $callback->($fh)	215	aio_open $pathname, $flags, $mode, $callback->($fh)
211	aio_close $fh, $callback->($status)	216	aio_close $fh, $callback->($status)
		217	aio_seek $fh,$offset,$whence, $callback->($offs)
212	aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)	218	aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
213	aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)	219	aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
214	aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval)	220	aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval)
215	aio_readahead $fh,$offset,$length, $callback->($retval)	221	aio_readahead $fh,$offset,$length, $callback->($retval)
216	aio_stat $fh_or_path, $callback->($status)	222	aio_stat $fh_or_path, $callback->($status)
217	aio_lstat $fh, $callback->($status)	223	aio_lstat $fh, $callback->($status)
218	aio_statvfs $fh_or_path, $callback->($statvfs)	224	aio_statvfs $fh_or_path, $callback->($statvfs)
219	aio_utime $fh_or_path, $atime, $mtime, $callback->($status)	225	aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
220	aio_chown $fh_or_path, $uid, $gid, $callback->($status)	226	aio_chown $fh_or_path, $uid, $gid, $callback->($status)
		227	aio_chmod $fh_or_path, $mode, $callback->($status)
221	aio_truncate $fh_or_path, $offset, $callback->($status)	228	aio_truncate $fh_or_path, $offset, $callback->($status)
222	aio_chmod $fh_or_path, $mode, $callback->($status)	229	aio_allocate $fh, $mode, $offset, $len, $callback->($status)
		230	aio_fiemap $fh, $start, $length, $flags, $count, $cb->(\@extents)
223	aio_unlink $pathname, $callback->($status)	231	aio_unlink $pathname, $callback->($status)
224	aio_mknod $path, $mode, $dev, $callback->($status)	232	aio_mknod $pathname, $mode, $dev, $callback->($status)
225	aio_link $srcpath, $dstpath, $callback->($status)	233	aio_link $srcpath, $dstpath, $callback->($status)
226	aio_symlink $srcpath, $dstpath, $callback->($status)	234	aio_symlink $srcpath, $dstpath, $callback->($status)
227	aio_readlink $path, $callback->($link)	235	aio_readlink $pathname, $callback->($link)
228	aio_realpath $path, $callback->($link)	236	aio_realpath $pathname, $callback->($path)
229	aio_rename $srcpath, $dstpath, $callback->($status)	237	aio_rename $srcpath, $dstpath, $callback->($status)
		238	aio_rename2 $srcpath, $dstpath, $flags, $callback->($status)
230	aio_mkdir $pathname, $mode, $callback->($status)	239	aio_mkdir $pathname, $mode, $callback->($status)
231	aio_rmdir $pathname, $callback->($status)	240	aio_rmdir $pathname, $callback->($status)
232	aio_readdir $pathname, $callback->($entries)	241	aio_readdir $pathname, $callback->($entries)
233	aio_readdirx $pathname, $flags, $callback->($entries, $flags)	242	aio_readdirx $pathname, $flags, $callback->($entries, $flags)
234	IO::AIO::READDIR_DENTS IO::AIO::READDIR_DIRS_FIRST	243	IO::AIO::READDIR_DENTS IO::AIO::READDIR_DIRS_FIRST
235	IO::AIO::READDIR_STAT_ORDER IO::AIO::READDIR_FOUND_UNKNOWN	244	IO::AIO::READDIR_STAT_ORDER IO::AIO::READDIR_FOUND_UNKNOWN
		245	aio_scandir $pathname, $maxreq, $callback->($dirs, $nondirs)
236	aio_load $path, $data, $callback->($status)	246	aio_load $pathname, $data, $callback->($status)
237	aio_copy $srcpath, $dstpath, $callback->($status)	247	aio_copy $srcpath, $dstpath, $callback->($status)
238	aio_move $srcpath, $dstpath, $callback->($status)	248	aio_move $srcpath, $dstpath, $callback->($status)
239	aio_scandir $path, $maxreq, $callback->($dirs, $nondirs)
240	aio_rmtree $path, $callback->($status)	249	aio_rmtree $pathname, $callback->($status)
		250	aio_fcntl $fh, $cmd, $arg, $callback->($status)
		251	aio_ioctl $fh, $request, $buf, $callback->($status)
241	aio_sync $callback->($status)	252	aio_sync $callback->($status)
		253	aio_syncfs $fh, $callback->($status)
242	aio_fsync $fh, $callback->($status)	254	aio_fsync $fh, $callback->($status)
243	aio_fdatasync $fh, $callback->($status)	255	aio_fdatasync $fh, $callback->($status)
244	aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status)	256	aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status)
245	aio_pathsync $path, $callback->($status)	257	aio_pathsync $pathname, $callback->($status)
246	aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)	258	aio_msync $scalar, $offset = 0, $length = undef, flags = MS_SYNC, $callback->($status)
247	aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)	259	aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
248	aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status)	260	aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status)
249	aio_mlockall $flags, $callback->($status)	261	aio_mlockall $flags, $callback->($status)
250	aio_group $callback->(...)	262	aio_group $callback->(...)
251	aio_nop $callback->()	263	aio_nop $callback->()
…		…
265	IO::AIO::idle_timeout $seconds	277	IO::AIO::idle_timeout $seconds
266	IO::AIO::max_outstanding $maxreqs	278	IO::AIO::max_outstanding $maxreqs
267	IO::AIO::nreqs	279	IO::AIO::nreqs
268	IO::AIO::nready	280	IO::AIO::nready
269	IO::AIO::npending	281	IO::AIO::npending
		282	$nfd = IO::AIO::get_fdlimit [EXPERIMENTAL]
		283	IO::AIO::min_fdlimit $nfd [EXPERIMENTAL]
270		284
271	IO::AIO::sendfile $ofh, $ifh, $offset, $count	285	IO::AIO::sendfile $ofh, $ifh, $offset, $count
272	IO::AIO::fadvise $fh, $offset, $len, $advice	286	IO::AIO::fadvise $fh, $offset, $len, $advice
		287	IO::AIO::mmap $scalar, $length, $prot, $flags[, $fh[, $offset]]
		288	IO::AIO::munmap $scalar
273	IO::AIO::madvise $scalar, $offset, $length, $advice	289	IO::AIO::madvise $scalar, $offset, $length, $advice
274	IO::AIO::mprotect $scalar, $offset, $length, $protect	290	IO::AIO::mprotect $scalar, $offset, $length, $protect
275	IO::AIO::munlock $scalar, $offset = 0, $length = undef	291	IO::AIO::munlock $scalar, $offset = 0, $length = undef
276	IO::AIO::munlockall	292	IO::AIO::munlockall
277		293
278	=head2 AIO REQUEST FUNCTIONS	294	=head2 API NOTES
279		295
280	All the C<aio_*> calls are more or less thin wrappers around the syscall	296	All the C<aio_*> calls are more or less thin wrappers around the syscall
281	with the same name (sans C<aio_>). The arguments are similar or identical,	297	with the same name (sans C<aio_>). The arguments are similar or identical,
282	and they all accept an additional (and optional) C<$callback> argument	298	and they all accept an additional (and optional) C<$callback> argument
283	which must be a code reference. This code reference will get called with	299	which must be a code reference. This code reference will be called after
284	the syscall return code (e.g. most syscalls return C<-1> on error, unlike	300	the syscall has been executed in an asynchronous fashion. The results
285	perl, which usually delivers "false") as its sole argument after the given	301	of the request will be passed as arguments to the callback (and, if an
286	syscall has been executed asynchronously.	302	error occured, in C<$!>) - for most requests the syscall return code (e.g.
		303	most syscalls return C<-1> on error, unlike perl, which usually delivers
		304	"false").
		305
		306	Some requests (such as C<aio_readdir>) pass the actual results and
		307	communicate failures by passing C<undef>.
287		308
288	All functions expecting a filehandle keep a copy of the filehandle	309	All functions expecting a filehandle keep a copy of the filehandle
289	internally until the request has finished.	310	internally until the request has finished.
290		311
291	All functions return request objects of type L<IO::AIO::REQ> that allow	312	All functions return request objects of type L<IO::AIO::REQ> that allow
292	further manipulation of those requests while they are in-flight.	313	further manipulation of those requests while they are in-flight.
293		314
294	The pathnames you pass to these routines I<must> be absolute and	315	The pathnames you pass to these routines I<should> be absolute. The
295	encoded as octets. The reason for the former is that at the time the	316	reason for this is that at the time the request is being executed, the
296	request is being executed, the current working directory could have	317	current working directory could have changed. Alternatively, you can
297	changed. Alternatively, you can make sure that you never change the	318	make sure that you never change the current working directory anywhere
298	current working directory anywhere in the program and then use relative	319	in the program and then use relative paths. You can also take advantage
299	paths.	320	of IO::AIOs working directory abstraction, that lets you specify paths
		321	relative to some previously-opened "working directory object" - see the
		322	description of the C<IO::AIO::WD> class later in this document.
300		323
301	To encode pathnames as octets, either make sure you either: a) always pass	324	To encode pathnames as octets, either make sure you either: a) always pass
302	in filenames you got from outside (command line, readdir etc.) without	325	in filenames you got from outside (command line, readdir etc.) without
303	tinkering, b) are ASCII or ISO 8859-1, c) use the Encode module and encode	326	tinkering, b) are in your native filesystem encoding, c) use the Encode
304	your pathnames to the locale (or other) encoding in effect in the user	327	module and encode your pathnames to the locale (or other) encoding in
305	environment, d) use Glib::filename_from_unicode on unicode filenames or e)	328	effect in the user environment, d) use Glib::filename_from_unicode on
306	use something else to ensure your scalar has the correct contents.	329	unicode filenames or e) use something else to ensure your scalar has the
		330	correct contents.
307		331
308	This works, btw. independent of the internal UTF-8 bit, which IO::AIO	332	This works, btw. independent of the internal UTF-8 bit, which IO::AIO
309	handles correctly whether it is set or not.	333	handles correctly whether it is set or not.
		334
		335	=head2 AIO REQUEST FUNCTIONS
310		336
311	=over 4	337	=over 4
312		338
313	=item $prev_pri = aioreq_pri [$pri]	339	=item $prev_pri = aioreq_pri [$pri]
314		340
…		…
344		370
345		371
346	=item aio_open $pathname, $flags, $mode, $callback->($fh)	372	=item aio_open $pathname, $flags, $mode, $callback->($fh)
347		373
348	Asynchronously open or create a file and call the callback with a newly	374	Asynchronously open or create a file and call the callback with a newly
349	created filehandle for the file.	375	created filehandle for the file (or C<undef> in case of an error).
350		376
351	The pathname passed to C<aio_open> must be absolute. See API NOTES, above,	377	The pathname passed to C<aio_open> must be absolute. See API NOTES, above,
352	for an explanation.	378	for an explanation.
353		379
354	The C<$flags> argument is a bitmask. See the C<Fcntl> module for a	380	The C<$flags> argument is a bitmask. See the C<Fcntl> module for a
…		…
377	following POSIX and non-POSIX constants are available (missing ones on	403	following POSIX and non-POSIX constants are available (missing ones on
378	your system are, as usual, C<0>):	404	your system are, as usual, C<0>):
379		405
380	C<O_ASYNC>, C<O_DIRECT>, C<O_NOATIME>, C<O_CLOEXEC>, C<O_NOCTTY>, C<O_NOFOLLOW>,	406	C<O_ASYNC>, C<O_DIRECT>, C<O_NOATIME>, C<O_CLOEXEC>, C<O_NOCTTY>, C<O_NOFOLLOW>,
381	C<O_NONBLOCK>, C<O_EXEC>, C<O_SEARCH>, C<O_DIRECTORY>, C<O_DSYNC>,	407	C<O_NONBLOCK>, C<O_EXEC>, C<O_SEARCH>, C<O_DIRECTORY>, C<O_DSYNC>,
382	C<O_RSYNC>, C<O_SYNC> and C<O_TTY_INIT>.	408	C<O_RSYNC>, C<O_SYNC>, C<O_PATH>, C<O_TMPFILE>, and C<O_TTY_INIT>.
383		409
384		410
385	=item aio_close $fh, $callback->($status)	411	=item aio_close $fh, $callback->($status)
386		412
387	Asynchronously close a file and call the callback with the result	413	Asynchronously close a file and call the callback with the result
…		…
397	Or in other words: the file descriptor will be closed, but it will not be	423	Or in other words: the file descriptor will be closed, but it will not be
398	free for reuse until the perl filehandle is closed.	424	free for reuse until the perl filehandle is closed.
399		425
400	=cut	426	=cut
401		427
		428	=item aio_seek $fh, $offset, $whence, $callback->($offs)
		429
		430	Seeks the filehandle to the new C<$offset>, similarly to perl's
		431	C<sysseek>. The C<$whence> can use the traditional values (C<0> for
		432	C<IO::AIO::SEEK_SET>, C<1> for C<IO::AIO::SEEK_CUR> or C<2> for
		433	C<IO::AIO::SEEK_END>).
		434
		435	The resulting absolute offset will be passed to the callback, or C<-1> in
		436	case of an error.
		437
		438	In theory, the C<$whence> constants could be different than the
		439	corresponding values from L<Fcntl>, but perl guarantees they are the same,
		440	so don't panic.
		441
		442	As a GNU/Linux (and maybe Solaris) extension, also the constants
		443	C<IO::AIO::SEEK_DATA> and C<IO::AIO::SEEK_HOLE> are available, if they
		444	could be found. No guarantees about suitability for use in C<aio_seek> or
		445	Perl's C<sysseek> can be made though, although I would naively assume they
		446	"just work".
		447
402	=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)	448	=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
403		449
404	=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)	450	=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
405		451
406	Reads or writes C<$length> bytes from or to the specified C<$fh> and	452	Reads or writes C<$length> bytes from or to the specified C<$fh> and
407	C<$offset> into the scalar given by C<$data> and offset C<$dataoffset>	453	C<$offset> into the scalar given by C<$data> and offset C<$dataoffset> and
408	and calls the callback without the actual number of bytes read (or -1 on	454	calls the callback with the actual number of bytes transferred (or -1 on
409	error, just like the syscall).	455	error, just like the syscall).
410		456
411	C<aio_read> will, like C<sysread>, shrink or grow the C<$data> scalar to	457	C<aio_read> will, like C<sysread>, shrink or grow the C<$data> scalar to
412	offset plus the actual number of bytes read.	458	offset plus the actual number of bytes read.
413		459
…		…
471	As native sendfile syscalls (as practically any non-POSIX interface hacked	517	As native sendfile syscalls (as practically any non-POSIX interface hacked
472	together in a hurry to improve benchmark numbers) tend to be rather buggy	518	together in a hurry to improve benchmark numbers) tend to be rather buggy
473	on many systems, this implementation tries to work around some known bugs	519	on many systems, this implementation tries to work around some known bugs
474	in Linux and FreeBSD kernels (probably others, too), but that might fail,	520	in Linux and FreeBSD kernels (probably others, too), but that might fail,
475	so you really really should check the return value of C<aio_sendfile> -	521	so you really really should check the return value of C<aio_sendfile> -
476	fewre bytes than expected might have been transferred.	522	fewer bytes than expected might have been transferred.
477		523
478		524
479	=item aio_readahead $fh,$offset,$length, $callback->($retval)	525	=item aio_readahead $fh,$offset,$length, $callback->($retval)
480		526
481	C<aio_readahead> populates the page cache with data from a file so that	527	C<aio_readahead> populates the page cache with data from a file so that
…		…
485	whole pages, so that offset is effectively rounded down to a page boundary	531	whole pages, so that offset is effectively rounded down to a page boundary
486	and bytes are read up to the next page boundary greater than or equal to	532	and bytes are read up to the next page boundary greater than or equal to
487	(off-set+length). C<aio_readahead> does not read beyond the end of the	533	(off-set+length). C<aio_readahead> does not read beyond the end of the
488	file. The current file offset of the file is left unchanged.	534	file. The current file offset of the file is left unchanged.
489		535
490	If that syscall doesn't exist (likely if your OS isn't Linux) it will be	536	If that syscall doesn't exist (likely if your kernel isn't Linux) it will
491	emulated by simply reading the data, which would have a similar effect.	537	be emulated by simply reading the data, which would have a similar effect.
492		538
493		539
494	=item aio_stat $fh_or_path, $callback->($status)	540	=item aio_stat $fh_or_path, $callback->($status)
495		541
496	=item aio_lstat $fh, $callback->($status)	542	=item aio_lstat $fh, $callback->($status)
…		…
565	namemax => 255,	611	namemax => 255,
566	frsize => 1024,	612	frsize => 1024,
567	fsid => 1810	613	fsid => 1810
568	}	614	}
569		615
		616	Here is a (likely partial - send me updates!) list of fsid values used by
		617	Linux - it is safe to hardcode these when C<$^O> is C<linux>:
		618
		619	0x0000adf5 adfs
		620	0x0000adff affs
		621	0x5346414f afs
		622	0x09041934 anon-inode filesystem
		623	0x00000187 autofs
		624	0x42465331 befs
		625	0x1badface bfs
		626	0x42494e4d binfmt_misc
		627	0x9123683e btrfs
		628	0x0027e0eb cgroupfs
		629	0xff534d42 cifs
		630	0x73757245 coda
		631	0x012ff7b7 coh
		632	0x28cd3d45 cramfs
		633	0x453dcd28 cramfs-wend (wrong endianness)
		634	0x64626720 debugfs
		635	0x00001373 devfs
		636	0x00001cd1 devpts
		637	0x0000f15f ecryptfs
		638	0x00414a53 efs
		639	0x0000137d ext
		640	0x0000ef53 ext2/ext3/ext4
		641	0x0000ef51 ext2
		642	0xf2f52010 f2fs
		643	0x00004006 fat
		644	0x65735546 fuseblk
		645	0x65735543 fusectl
		646	0x0bad1dea futexfs
		647	0x01161970 gfs2
		648	0x47504653 gpfs
		649	0x00004244 hfs
		650	0xf995e849 hpfs
		651	0x00c0ffee hostfs
		652	0x958458f6 hugetlbfs
		653	0x2bad1dea inotifyfs
		654	0x00009660 isofs
		655	0x000072b6 jffs2
		656	0x3153464a jfs
		657	0x6b414653 k-afs
		658	0x0bd00bd0 lustre
		659	0x0000137f minix
		660	0x0000138f minix 30 char names
		661	0x00002468 minix v2
		662	0x00002478 minix v2 30 char names
		663	0x00004d5a minix v3
		664	0x19800202 mqueue
		665	0x00004d44 msdos
		666	0x0000564c novell
		667	0x00006969 nfs
		668	0x6e667364 nfsd
		669	0x00003434 nilfs
		670	0x5346544e ntfs
		671	0x00009fa1 openprom
		672	0x7461636F ocfs2
		673	0x00009fa0 proc
		674	0x6165676c pstorefs
		675	0x0000002f qnx4
		676	0x68191122 qnx6
		677	0x858458f6 ramfs
		678	0x52654973 reiserfs
		679	0x00007275 romfs
		680	0x67596969 rpc_pipefs
		681	0x73636673 securityfs
		682	0xf97cff8c selinux
		683	0x0000517b smb
		684	0x534f434b sockfs
		685	0x73717368 squashfs
		686	0x62656572 sysfs
		687	0x012ff7b6 sysv2
		688	0x012ff7b5 sysv4
		689	0x01021994 tmpfs
		690	0x15013346 udf
		691	0x00011954 ufs
		692	0x54190100 ufs byteswapped
		693	0x00009fa2 usbdevfs
		694	0x01021997 v9fs
		695	0xa501fcf5 vxfs
		696	0xabba1974 xenfs
		697	0x012ff7b4 xenix
		698	0x58465342 xfs
		699	0x012fd16d xia
570		700
571	=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status)	701	=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
572		702
573	Works like perl's C<utime> function (including the special case of $atime	703	Works like perl's C<utime> function (including the special case of $atime
574	and $mtime being undef). Fractional times are supported if the underlying	704	and $mtime being undef). Fractional times are supported if the underlying
…		…
602	=item aio_truncate $fh_or_path, $offset, $callback->($status)	732	=item aio_truncate $fh_or_path, $offset, $callback->($status)
603		733
604	Works like truncate(2) or ftruncate(2).	734	Works like truncate(2) or ftruncate(2).
605		735
606		736
		737	=item aio_allocate $fh, $mode, $offset, $len, $callback->($status)
		738
		739	Allocates or frees disk space according to the C<$mode> argument. See the
		740	linux C<fallocate> documentation for details.
		741
		742	C<$mode> is usually C<0> or C<IO::AIO::FALLOC_FL_KEEP_SIZE> to allocate
		743	space, or C<IO::AIO::FALLOC_FL_PUNCH_HOLE \| IO::AIO::FALLOC_FL_KEEP_SIZE>,
		744	to deallocate a file range.
		745
		746	IO::AIO also supports C<FALLOC_FL_COLLAPSE_RANGE>, to remove a range
		747	(without leaving a hole), C<FALLOC_FL_ZERO_RANGE>, to zero a range,
		748	C<FALLOC_FL_INSERT_RANGE> to insert a range and C<FALLOC_FL_UNSHARE_RANGE>
		749	to unshare shared blocks (see your L<fallocate(2)> manpage).
		750
		751	The file system block size used by C<fallocate> is presumably the
		752	C<f_bsize> returned by C<statvfs>, but different filesystems and filetypes
		753	can dictate other limitations.
		754
		755	If C<fallocate> isn't available or cannot be emulated (currently no
		756	emulation will be attempted), passes C<-1> and sets C<$!> to C<ENOSYS>.
		757
		758
607	=item aio_chmod $fh_or_path, $mode, $callback->($status)	759	=item aio_chmod $fh_or_path, $mode, $callback->($status)
608		760
609	Works like perl's C<chmod> function.	761	Works like perl's C<chmod> function.
610		762
611		763
…		…
613		765
614	Asynchronously unlink (delete) a file and call the callback with the	766	Asynchronously unlink (delete) a file and call the callback with the
615	result code.	767	result code.
616		768
617		769
618	=item aio_mknod $path, $mode, $dev, $callback->($status)	770	=item aio_mknod $pathname, $mode, $dev, $callback->($status)
619		771
620	[EXPERIMENTAL]	772	[EXPERIMENTAL]
621		773
622	Asynchronously create a device node (or fifo). See mknod(2).	774	Asynchronously create a device node (or fifo). See mknod(2).
623		775
624	The only (POSIX-) portable way of calling this function is:	776	The only (POSIX-) portable way of calling this function is:
625		777
626	aio_mknod $path, IO::AIO::S_IFIFO \| $mode, 0, sub { ...	778	aio_mknod $pathname, IO::AIO::S_IFIFO \| $mode, 0, sub { ...
627		779
628	See C<aio_stat> for info about some potentially helpful extra constants	780	See C<aio_stat> for info about some potentially helpful extra constants
629	and functions.	781	and functions.
630		782
631	=item aio_link $srcpath, $dstpath, $callback->($status)	783	=item aio_link $srcpath, $dstpath, $callback->($status)
…		…
638		790
639	Asynchronously create a new symbolic link to the existing object at C<$srcpath> at	791	Asynchronously create a new symbolic link to the existing object at C<$srcpath> at
640	the path C<$dstpath> and call the callback with the result code.	792	the path C<$dstpath> and call the callback with the result code.
641		793
642		794
643	=item aio_readlink $path, $callback->($link)	795	=item aio_readlink $pathname, $callback->($link)
644		796
645	Asynchronously read the symlink specified by C<$path> and pass it to	797	Asynchronously read the symlink specified by C<$path> and pass it to
646	the callback. If an error occurs, nothing or undef gets passed to the	798	the callback. If an error occurs, nothing or undef gets passed to the
647	callback.	799	callback.
648		800
649		801
650	=item aio_realpath $path, $callback->($path)	802	=item aio_realpath $pathname, $callback->($path)
651		803
652	Asynchronously make the path absolute and resolve any symlinks in	804	Asynchronously make the path absolute and resolve any symlinks in
653	C<$path>. The resulting path only consists of directories (Same as	805	C<$path>. The resulting path only consists of directories (same as
654	L<Cwd::realpath>).	806	L<Cwd::realpath>).
655		807
656	This request can be used to get the absolute path of the current working	808	This request can be used to get the absolute path of the current working
657	directory by passing it a path of F<.> (a single dot).	809	directory by passing it a path of F<.> (a single dot).
658		810
659		811
660	=item aio_rename $srcpath, $dstpath, $callback->($status)	812	=item aio_rename $srcpath, $dstpath, $callback->($status)
661		813
662	Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as	814	Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as
663	rename(2) and call the callback with the result code.	815	rename(2) and call the callback with the result code.
		816
		817	On systems that support the AIO::WD working directory abstraction
		818	natively, the case C<[$wd, "."]> as C<$srcpath> is specialcased - instead
		819	of failing, C<rename> is called on the absolute path of C<$wd>.
		820
		821
		822	=item aio_rename2 $srcpath, $dstpath, $flags, $callback->($status)
		823
		824	Basically a version of C<aio_rename> with an additional C<$flags>
		825	argument. Calling this with C<$flags=0> is the same as calling
		826	C<aio_rename>.
		827
		828	Non-zero flags are currently only supported on GNU/Linux systems that
		829	support renameat2. Other systems fail with C<ENOSYS> in this case.
		830
		831	The following constants are available (missing ones are, as usual C<0>),
		832	see renameat2(2) for details:
		833
		834	C<IO::AIO::RENAME_NOREPLACE>, C<IO::AIO::RENAME_EXCHANGE>
		835	and C<IO::AIO::RENAME_WHITEOUT>.
664		836
665		837
666	=item aio_mkdir $pathname, $mode, $callback->($status)	838	=item aio_mkdir $pathname, $mode, $callback->($status)
667		839
668	Asynchronously mkdir (create) a directory and call the callback with	840	Asynchronously mkdir (create) a directory and call the callback with
…		…
673	=item aio_rmdir $pathname, $callback->($status)	845	=item aio_rmdir $pathname, $callback->($status)
674		846
675	Asynchronously rmdir (delete) a directory and call the callback with the	847	Asynchronously rmdir (delete) a directory and call the callback with the
676	result code.	848	result code.
677		849
		850	On systems that support the AIO::WD working directory abstraction
		851	natively, the case C<[$wd, "."]> is specialcased - instead of failing,
		852	C<rmdir> is called on the absolute path of C<$wd>.
		853
678		854
679	=item aio_readdir $pathname, $callback->($entries)	855	=item aio_readdir $pathname, $callback->($entries)
680		856
681	Unlike the POSIX call of the same name, C<aio_readdir> reads an entire	857	Unlike the POSIX call of the same name, C<aio_readdir> reads an entire
682	directory (i.e. opendir + readdir + closedir). The entries will not be	858	directory (i.e. opendir + readdir + closedir). The entries will not be
…		…
686	array-ref with the filenames.	862	array-ref with the filenames.
687		863
688		864
689	=item aio_readdirx $pathname, $flags, $callback->($entries, $flags)	865	=item aio_readdirx $pathname, $flags, $callback->($entries, $flags)
690		866
691	Quite similar to C<aio_readdir>, but the C<$flags> argument allows to tune	867	Quite similar to C<aio_readdir>, but the C<$flags> argument allows one to
692	behaviour and output format. In case of an error, C<$entries> will be	868	tune behaviour and output format. In case of an error, C<$entries> will be
693	C<undef>.	869	C<undef>.
694		870
695	The flags are a combination of the following constants, ORed together (the	871	The flags are a combination of the following constants, ORed together (the
696	flags will also be passed to the callback, possibly modified):	872	flags will also be passed to the callback, possibly modified):
697		873
…		…
744		920
745	=item IO::AIO::READDIR_FOUND_UNKNOWN	921	=item IO::AIO::READDIR_FOUND_UNKNOWN
746		922
747	This flag should not be set when calling C<aio_readdirx>. Instead, it	923	This flag should not be set when calling C<aio_readdirx>. Instead, it
748	is being set by C<aio_readdirx>, when any of the C<$type>'s found were	924	is being set by C<aio_readdirx>, when any of the C<$type>'s found were
749	C<IO::AIO::DT_UNKNOWN>. The absense of this flag therefore indicates that all	925	C<IO::AIO::DT_UNKNOWN>. The absence of this flag therefore indicates that all
750	C<$type>'s are known, which can be used to speed up some algorithms.	926	C<$type>'s are known, which can be used to speed up some algorithms.
751		927
752	=back	928	=back
753		929
754		930
755	=item aio_load $path, $data, $callback->($status)	931	=item aio_load $pathname, $data, $callback->($status)
756		932
757	This is a composite request that tries to fully load the given file into	933	This is a composite request that tries to fully load the given file into
758	memory. Status is the same as with aio_read.	934	memory. Status is the same as with aio_read.
759		935
760	=cut	936	=cut
…		…
783	=item aio_copy $srcpath, $dstpath, $callback->($status)	959	=item aio_copy $srcpath, $dstpath, $callback->($status)
784		960
785	Try to copy the I<file> (directories not supported as either source or	961	Try to copy the I<file> (directories not supported as either source or
786	destination) from C<$srcpath> to C<$dstpath> and call the callback with	962	destination) from C<$srcpath> to C<$dstpath> and call the callback with
787	a status of C<0> (ok) or C<-1> (error, see C<$!>).	963	a status of C<0> (ok) or C<-1> (error, see C<$!>).
		964
		965	Existing destination files will be truncated.
788		966
789	This is a composite request that creates the destination file with	967	This is a composite request that creates the destination file with
790	mode 0200 and copies the contents of the source file into it using	968	mode 0200 and copies the contents of the source file into it using
791	C<aio_sendfile>, followed by restoring atime, mtime, access mode and	969	C<aio_sendfile>, followed by restoring atime, mtime, access mode and
792	uid/gid, in that order.	970	uid/gid, in that order.
…		…
895	};	1073	};
896		1074
897	$grp	1075	$grp
898	}	1076	}
899		1077
900	=item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs)	1078	=item aio_scandir $pathname, $maxreq, $callback->($dirs, $nondirs)
901		1079
902	Scans a directory (similar to C<aio_readdir>) but additionally tries to	1080	Scans a directory (similar to C<aio_readdir>) but additionally tries to
903	efficiently separate the entries of directory C<$path> into two sets of	1081	efficiently separate the entries of directory C<$path> into two sets of
904	names, directories you can recurse into (directories), and ones you cannot	1082	names, directories you can recurse into (directories), and ones you cannot
905	recurse into (everything else, including symlinks to directories).	1083	recurse into (everything else, including symlinks to directories).
906		1084
907	C<aio_scandir> is a composite request that creates of many sub requests_	1085	C<aio_scandir> is a composite request that generates many sub requests.
908	C<$maxreq> specifies the maximum number of outstanding aio requests that	1086	C<$maxreq> specifies the maximum number of outstanding aio requests that
909	this function generates. If it is C<< <= 0 >>, then a suitable default	1087	this function generates. If it is C<< <= 0 >>, then a suitable default
910	will be chosen (currently 4).	1088	will be chosen (currently 4).
911		1089
912	On error, the callback is called without arguments, otherwise it receives	1090	On error, the callback is called without arguments, otherwise it receives
…		…
936	Then entries will be sorted into likely directories a non-initial dot	1114	Then entries will be sorted into likely directories a non-initial dot
937	currently) and likely non-directories (see C<aio_readdirx>). Then every	1115	currently) and likely non-directories (see C<aio_readdirx>). Then every
938	entry plus an appended C</.> will be C<stat>'ed, likely directories first,	1116	entry plus an appended C</.> will be C<stat>'ed, likely directories first,
939	in order of their inode numbers. If that succeeds, it assumes that the	1117	in order of their inode numbers. If that succeeds, it assumes that the
940	entry is a directory or a symlink to directory (which will be checked	1118	entry is a directory or a symlink to directory (which will be checked
941	seperately). This is often faster than stat'ing the entry itself because	1119	separately). This is often faster than stat'ing the entry itself because
942	filesystems might detect the type of the entry without reading the inode	1120	filesystems might detect the type of the entry without reading the inode
943	data (e.g. ext2fs filetype feature), even on systems that cannot return	1121	data (e.g. ext2fs filetype feature), even on systems that cannot return
944	the filetype information on readdir.	1122	the filetype information on readdir.
945		1123
946	If the known number of directories (link count - 2) has been reached, the	1124	If the known number of directories (link count - 2) has been reached, the
…		…
962		1140
963	my $grp = aio_group $cb;	1141	my $grp = aio_group $cb;
964		1142
965	$maxreq = 4 if $maxreq <= 0;	1143	$maxreq = 4 if $maxreq <= 0;
966		1144
967	# stat once	1145	# get a wd object
968	aioreq_pri $pri;	1146	aioreq_pri $pri;
969	add $grp aio_stat $path, sub {	1147	add $grp aio_wd $path, sub {
		1148	$_[0]
970	return $grp->result () if $_[0];	1149	or return $grp->result ();
971	my $now = time;
972	my $hash1 = join ":", (stat _)[0,1,3,7,9];
973		1150
974	# read the directory entries	1151	my $wd = [shift, "."];
		1152
		1153	# stat once
975	aioreq_pri $pri;	1154	aioreq_pri $pri;
976	add $grp aio_readdirx $path, READDIR_DIRS_FIRST, sub {	1155	add $grp aio_stat $wd, sub {
977	my $entries = shift
978	or return $grp->result ();	1156	return $grp->result () if $_[0];
		1157	my $now = time;
		1158	my $hash1 = join ":", (stat _)[0,1,3,7,9];
979		1159
980	# stat the dir another time	1160	# read the directory entries
981	aioreq_pri $pri;	1161	aioreq_pri $pri;
		1162	add $grp aio_readdirx $wd, READDIR_DIRS_FIRST, sub {
		1163	my $entries = shift
		1164	or return $grp->result ();
		1165
		1166	# stat the dir another time
		1167	aioreq_pri $pri;
982	add $grp aio_stat $path, sub {	1168	add $grp aio_stat $wd, sub {
983	my $hash2 = join ":", (stat _)[0,1,3,7,9];	1169	my $hash2 = join ":", (stat _)[0,1,3,7,9];
984		1170
985	my $ndirs;	1171	my $ndirs;
986		1172
987	# take the slow route if anything looks fishy	1173	# take the slow route if anything looks fishy
988	if ($hash1 ne $hash2 or (stat _)[9] == $now) {	1174	if ($hash1 ne $hash2 or (stat _)[9] == $now) {
989	$ndirs = -1;	1175	$ndirs = -1;
990	} else {	1176	} else {
991	# if nlink == 2, we are finished	1177	# if nlink == 2, we are finished
992	# for non-posix-fs's, we rely on nlink < 2	1178	# for non-posix-fs's, we rely on nlink < 2
993	$ndirs = (stat _)[3] - 2	1179	$ndirs = (stat _)[3] - 2
994	or return $grp->result ([], $entries);	1180	or return $grp->result ([], $entries);
995	}	1181	}
996		1182
997	my (@dirs, @nondirs);	1183	my (@dirs, @nondirs);
998		1184
999	my $statgrp = add $grp aio_group sub {	1185	my $statgrp = add $grp aio_group sub {
1000	$grp->result (\@dirs, \@nondirs);	1186	$grp->result (\@dirs, \@nondirs);
1001	};	1187	};
1002		1188
1003	limit $statgrp $maxreq;	1189	limit $statgrp $maxreq;
1004	feed $statgrp sub {	1190	feed $statgrp sub {
1005	return unless @$entries;	1191	return unless @$entries;
1006	my $entry = shift @$entries;	1192	my $entry = shift @$entries;
1007		1193
1008	aioreq_pri $pri;	1194	aioreq_pri $pri;
		1195	$wd->[1] = "$entry/.";
1009	add $statgrp aio_stat "$path/$entry/.", sub {	1196	add $statgrp aio_stat $wd, sub {
1010	if ($_[0] < 0) {	1197	if ($_[0] < 0) {
1011	push @nondirs, $entry;	1198	push @nondirs, $entry;
1012	} else {	1199	} else {
1013	# need to check for real directory	1200	# need to check for real directory
1014	aioreq_pri $pri;	1201	aioreq_pri $pri;
		1202	$wd->[1] = $entry;
1015	add $statgrp aio_lstat "$path/$entry", sub {	1203	add $statgrp aio_lstat $wd, sub {
1016	if (-d _) {	1204	if (-d _) {
1017	push @dirs, $entry;	1205	push @dirs, $entry;
1018		1206
1019	unless (--$ndirs) {	1207	unless (--$ndirs) {
1020	push @nondirs, @$entries;	1208	push @nondirs, @$entries;
1021	feed $statgrp;	1209	feed $statgrp;
		1210	}
		1211	} else {
		1212	push @nondirs, $entry;
1022	}	1213	}
1023	} else {
1024	push @nondirs, $entry;
1025	}	1214	}
1026	}	1215	}
1027	}	1216	};
1028	};	1217	};
1029	};	1218	};
1030	};	1219	};
1031	};	1220	};
1032	};	1221	};
1033		1222
1034	$grp	1223	$grp
1035	}	1224	}
1036		1225
1037	=item aio_rmtree $path, $callback->($status)	1226	=item aio_rmtree $pathname, $callback->($status)
1038		1227
1039	Delete a directory tree starting (and including) C<$path>, return the	1228	Delete a directory tree starting (and including) C<$path>, return the
1040	status of the final C<rmdir> only. This is a composite request that	1229	status of the final C<rmdir> only. This is a composite request that
1041	uses C<aio_scandir> to recurse into and rmdir directories, and unlink	1230	uses C<aio_scandir> to recurse into and rmdir directories, and unlink
1042	everything else.	1231	everything else.
1043		1232
1044	=cut	1233	=cut
1045		1234
…		…
1067	};	1256	};
1068		1257
1069	$grp	1258	$grp
1070	}	1259	}
1071		1260
		1261	=item aio_fcntl $fh, $cmd, $arg, $callback->($status)
		1262
		1263	=item aio_ioctl $fh, $request, $buf, $callback->($status)
		1264
		1265	These work just like the C<fcntl> and C<ioctl> built-in functions, except
		1266	they execute asynchronously and pass the return value to the callback.
		1267
		1268	Both calls can be used for a lot of things, some of which make more sense
		1269	to run asynchronously in their own thread, while some others make less
		1270	sense. For example, calls that block waiting for external events, such
		1271	as locking, will also lock down an I/O thread while it is waiting, which
		1272	can deadlock the whole I/O system. At the same time, there might be no
		1273	alternative to using a thread to wait.
		1274
		1275	So in general, you should only use these calls for things that do
		1276	(filesystem) I/O, not for things that wait for other events (network,
		1277	other processes), although if you are careful and know what you are doing,
		1278	you still can.
		1279
		1280	The following constants are available (missing ones are, as usual C<0>):
		1281
		1282	C<F_DUPFD_CLOEXEC>,
		1283
		1284	C<F_OFD_GETLK>, C<F_OFD_SETLK>, C<F_OFD_GETLKW>,
		1285
		1286	C<FIFREEZE>, C<FITHAW>, C<FITRIM>, C<FICLONE>, C<FICLONERANGE>, C<FIDEDUPERANGE>.
		1287
		1288	C<FS_IOC_GETFLAGS>, C<FS_IOC_SETFLAGS>, C<FS_IOC_GETVERSION>, C<FS_IOC_SETVERSION>,
		1289	C<FS_IOC_FIEMAP>.
		1290
		1291	C<FS_IOC_FSGETXATTR>, C<FS_IOC_FSSETXATTR>, C<FS_IOC_SET_ENCRYPTION_POLICY>,
		1292	C<FS_IOC_GET_ENCRYPTION_PWSALT>, C<FS_IOC_GET_ENCRYPTION_POLICY>, C<FS_KEY_DESCRIPTOR_SIZE>.
		1293
		1294	C<FS_SECRM_FL>, C<FS_UNRM_FL>, C<FS_COMPR_FL>, C<FS_SYNC_FL>, C<FS_IMMUTABLE_FL>,
		1295	C<FS_APPEND_FL>, C<FS_NODUMP_FL>, C<FS_NOATIME_FL>, C<FS_DIRTY_FL>,
		1296	C<FS_COMPRBLK_FL>, C<FS_NOCOMP_FL>, C<FS_ENCRYPT_FL>, C<FS_BTREE_FL>,
		1297	C<FS_INDEX_FL>, C<FS_JOURNAL_DATA_FL>, C<FS_NOTAIL_FL>, C<FS_DIRSYNC_FL>, C<FS_TOPDIR_FL>,
		1298	C<FS_FL_USER_MODIFIABLE>.
		1299
		1300	C<FS_XFLAG_REALTIME>, C<FS_XFLAG_PREALLOC>, C<FS_XFLAG_IMMUTABLE>, C<FS_XFLAG_APPEND>,
		1301	C<FS_XFLAG_SYNC>, C<FS_XFLAG_NOATIME>, C<FS_XFLAG_NODUMP>, C<FS_XFLAG_RTINHERIT>,
		1302	C<FS_XFLAG_PROJINHERIT>, C<FS_XFLAG_NOSYMLINKS>, C<FS_XFLAG_EXTSIZE>, C<FS_XFLAG_EXTSZINHERIT>,
		1303	C<FS_XFLAG_NODEFRAG>, C<FS_XFLAG_FILESTREAM>, C<FS_XFLAG_DAX>, C<FS_XFLAG_HASATTR>,
		1304
1072	=item aio_sync $callback->($status)	1305	=item aio_sync $callback->($status)
1073		1306
1074	Asynchronously call sync and call the callback when finished.	1307	Asynchronously call sync and call the callback when finished.
1075		1308
1076	=item aio_fsync $fh, $callback->($status)	1309	=item aio_fsync $fh, $callback->($status)
…		…
1083	Asynchronously call fdatasync on the given filehandle and call the	1316	Asynchronously call fdatasync on the given filehandle and call the
1084	callback with the fdatasync result code.	1317	callback with the fdatasync result code.
1085		1318
1086	If this call isn't available because your OS lacks it or it couldn't be	1319	If this call isn't available because your OS lacks it or it couldn't be
1087	detected, it will be emulated by calling C<fsync> instead.	1320	detected, it will be emulated by calling C<fsync> instead.
		1321
		1322	=item aio_syncfs $fh, $callback->($status)
		1323
		1324	Asynchronously call the syncfs syscall to sync the filesystem associated
		1325	to the given filehandle and call the callback with the syncfs result
		1326	code. If syncfs is not available, calls sync(), but returns C<-1> and sets
		1327	errno to C<ENOSYS> nevertheless.
1088		1328
1089	=item aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status)	1329	=item aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status)
1090		1330
1091	Sync the data portion of the file specified by C<$offset> and C<$length>	1331	Sync the data portion of the file specified by C<$offset> and C<$length>
1092	to disk (but NOT the metadata), by calling the Linux-specific	1332	to disk (but NOT the metadata), by calling the Linux-specific
…		…
1096	C<$flags> can be a combination of C<IO::AIO::SYNC_FILE_RANGE_WAIT_BEFORE>,	1336	C<$flags> can be a combination of C<IO::AIO::SYNC_FILE_RANGE_WAIT_BEFORE>,
1097	C<IO::AIO::SYNC_FILE_RANGE_WRITE> and	1337	C<IO::AIO::SYNC_FILE_RANGE_WRITE> and
1098	C<IO::AIO::SYNC_FILE_RANGE_WAIT_AFTER>: refer to the sync_file_range	1338	C<IO::AIO::SYNC_FILE_RANGE_WAIT_AFTER>: refer to the sync_file_range
1099	manpage for details.	1339	manpage for details.
1100		1340
1101	=item aio_pathsync $path, $callback->($status)	1341	=item aio_pathsync $pathname, $callback->($status)
1102		1342
1103	This request tries to open, fsync and close the given path. This is a	1343	This request tries to open, fsync and close the given path. This is a
1104	composite request intended to sync directories after directory operations	1344	composite request intended to sync directories after directory operations
1105	(E.g. rename). This might not work on all operating systems or have any	1345	(E.g. rename). This might not work on all operating systems or have any
1106	specific effect, but usually it makes sure that directory changes get	1346	specific effect, but usually it makes sure that directory changes get
…		…
1137	};	1377	};
1138		1378
1139	$grp	1379	$grp
1140	}	1380	}
1141		1381
1142	=item aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)	1382	=item aio_msync $scalar, $offset = 0, $length = undef, flags = MS_SYNC, $callback->($status)
1143		1383
1144	This is a rather advanced IO::AIO call, which only works on mmap(2)ed	1384	This is a rather advanced IO::AIO call, which only works on mmap(2)ed
1145	scalars (see the C<IO::AIO::mmap> function, although it also works on data	1385	scalars (see the C<IO::AIO::mmap> function, although it also works on data
1146	scalars managed by the L<Sys::Mmap> or L<Mmap> modules, note that the	1386	scalars managed by the L<Sys::Mmap> or L<Mmap> modules, note that the
1147	scalar must only be modified in-place while an aio operation is pending on	1387	scalar must only be modified in-place while an aio operation is pending on
…		…
1149		1389
1150	It calls the C<msync> function of your OS, if available, with the memory	1390	It calls the C<msync> function of your OS, if available, with the memory
1151	area starting at C<$offset> in the string and ending C<$length> bytes	1391	area starting at C<$offset> in the string and ending C<$length> bytes
1152	later. If C<$length> is negative, counts from the end, and if C<$length>	1392	later. If C<$length> is negative, counts from the end, and if C<$length>
1153	is C<undef>, then it goes till the end of the string. The flags can be	1393	is C<undef>, then it goes till the end of the string. The flags can be
1154	a combination of C<IO::AIO::MS_ASYNC>, C<IO::AIO::MS_INVALIDATE> and	1394	either C<IO::AIO::MS_ASYNC> or C<IO::AIO::MS_SYNC>, plus an optional
1155	C<IO::AIO::MS_SYNC>.	1395	C<IO::AIO::MS_INVALIDATE>.
1156		1396
1157	=item aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)	1397	=item aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
1158		1398
1159	This is a rather advanced IO::AIO call, which works best on mmap(2)ed	1399	This is a rather advanced IO::AIO call, which works best on mmap(2)ed
1160	scalars.	1400	scalars.
1161		1401
1162	It touches (reads or writes) all memory pages in the specified	1402	It touches (reads or writes) all memory pages in the specified
1163	range inside the scalar. All caveats and parameters are the same	1403	range inside the scalar. All caveats and parameters are the same
1164	as for C<aio_msync>, above, except for flags, which must be either	1404	as for C<aio_msync>, above, except for flags, which must be either
1165	C<0> (which reads all pages and ensures they are instantiated) or	1405	C<0> (which reads all pages and ensures they are instantiated) or
1166	C<IO::AIO::MT_MODIFY>, which modifies the memory page s(by reading and	1406	C<IO::AIO::MT_MODIFY>, which modifies the memory pages (by reading and
1167	writing an octet from it, which dirties the page).	1407	writing an octet from it, which dirties the page).
1168		1408
1169	=item aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status)	1409	=item aio_mlock $scalar, $offset = 0, $length = undef, $callback->($status)
1170		1410
1171	This is a rather advanced IO::AIO call, which works best on mmap(2)ed	1411	This is a rather advanced IO::AIO call, which works best on mmap(2)ed
…		…
1202	documented under L<MISCELLANEOUS FUNCTIONS>.	1442	documented under L<MISCELLANEOUS FUNCTIONS>.
1203		1443
1204	Example: asynchronously lock all current and future pages into memory.	1444	Example: asynchronously lock all current and future pages into memory.
1205		1445
1206	aio_mlockall IO::AIO::MCL_FUTURE;	1446	aio_mlockall IO::AIO::MCL_FUTURE;
		1447
		1448	=item aio_fiemap $fh, $start, $length, $flags, $count, $cb->(\@extents)
		1449
		1450	Queries the extents of the given file (by calling the Linux C<FIEMAP>
		1451	ioctl, see L<http://cvs.schmorp.de/IO-AIO/doc/fiemap.txt> for details). If
		1452	the ioctl is not available on your OS, then this request will fail with
		1453	C<ENOSYS>.
		1454
		1455	C<$start> is the starting offset to query extents for, C<$length> is the
		1456	size of the range to query - if it is C<undef>, then the whole file will
		1457	be queried.
		1458
		1459	C<$flags> is a combination of flags (C<IO::AIO::FIEMAP_FLAG_SYNC> or
		1460	C<IO::AIO::FIEMAP_FLAG_XATTR> - C<IO::AIO::FIEMAP_FLAGS_COMPAT> is also
		1461	exported), and is normally C<0> or C<IO::AIO::FIEMAP_FLAG_SYNC> to query
		1462	the data portion.
		1463
		1464	C<$count> is the maximum number of extent records to return. If it is
		1465	C<undef>, then IO::AIO queries all extents of the range. As a very special
		1466	case, if it is C<0>, then the callback receives the number of extents
		1467	instead of the extents themselves (which is unreliable, see below).
		1468
		1469	If an error occurs, the callback receives no arguments. The special
		1470	C<errno> value C<IO::AIO::EBADR> is available to test for flag errors.
		1471
		1472	Otherwise, the callback receives an array reference with extent
		1473	structures. Each extent structure is an array reference itself, with the
		1474	following members:
		1475
		1476	[$logical, $physical, $length, $flags]
		1477
		1478	Flags is any combination of the following flag values (typically either C<0>
		1479	or C<IO::AIO::FIEMAP_EXTENT_LAST> (1)):
		1480
		1481	C<IO::AIO::FIEMAP_EXTENT_LAST>, C<IO::AIO::FIEMAP_EXTENT_UNKNOWN>,
		1482	C<IO::AIO::FIEMAP_EXTENT_DELALLOC>, C<IO::AIO::FIEMAP_EXTENT_ENCODED>,
		1483	C<IO::AIO::FIEMAP_EXTENT_DATA_ENCRYPTED>, C<IO::AIO::FIEMAP_EXTENT_NOT_ALIGNED>,
		1484	C<IO::AIO::FIEMAP_EXTENT_DATA_INLINE>, C<IO::AIO::FIEMAP_EXTENT_DATA_TAIL>,
		1485	C<IO::AIO::FIEMAP_EXTENT_UNWRITTEN>, C<IO::AIO::FIEMAP_EXTENT_MERGED> or
		1486	C<IO::AIO::FIEMAP_EXTENT_SHARED>.
		1487
		1488	At the time of this writing (Linux 3.2), this request is unreliable unless
		1489	C<$count> is C<undef>, as the kernel has all sorts of bugs preventing
		1490	it to return all extents of a range for files with a large number of
		1491	extents. The code (only) works around all these issues if C<$count> is
		1492	C<undef>.
1207		1493
1208	=item aio_group $callback->(...)	1494	=item aio_group $callback->(...)
1209		1495
1210	This is a very special aio request: Instead of doing something, it is a	1496	This is a very special aio request: Instead of doing something, it is a
1211	container for other aio requests, which is useful if you want to bundle	1497	container for other aio requests, which is useful if you want to bundle
…		…
1248	like sleep and file handle readable/writable, the overhead this creates is	1534	like sleep and file handle readable/writable, the overhead this creates is
1249	immense (it blocks a thread for a long time) so do not use this function	1535	immense (it blocks a thread for a long time) so do not use this function
1250	except to put your application under artificial I/O pressure.	1536	except to put your application under artificial I/O pressure.
1251		1537
1252	=back	1538	=back
		1539
		1540
		1541	=head2 IO::AIO::WD - multiple working directories
		1542
		1543	Your process only has one current working directory, which is used by all
		1544	threads. This makes it hard to use relative paths (some other component
		1545	could call C<chdir> at any time, and it is hard to control when the path
		1546	will be used by IO::AIO).
		1547
		1548	One solution for this is to always use absolute paths. This usually works,
		1549	but can be quite slow (the kernel has to walk the whole path on every
		1550	access), and can also be a hassle to implement.
		1551
		1552	Newer POSIX systems have a number of functions (openat, fdopendir,
		1553	futimensat and so on) that make it possible to specify working directories
		1554	per operation.
		1555
		1556	For portability, and because the clowns who "designed", or shall I write,
		1557	perpetrated this new interface were obviously half-drunk, this abstraction
		1558	cannot be perfect, though.
		1559
		1560	IO::AIO allows you to convert directory paths into a so-called IO::AIO::WD
		1561	object. This object stores the canonicalised, absolute version of the
		1562	path, and on systems that allow it, also a directory file descriptor.
		1563
		1564	Everywhere where a pathname is accepted by IO::AIO (e.g. in C<aio_stat>
		1565	or C<aio_unlink>), one can specify an array reference with an IO::AIO::WD
		1566	object and a pathname instead (or the IO::AIO::WD object alone, which
		1567	gets interpreted as C<[$wd, "."]>). If the pathname is absolute, the
		1568	IO::AIO::WD object is ignored, otherwise the pathname is resolved relative
		1569	to that IO::AIO::WD object.
		1570
		1571	For example, to get a wd object for F</etc> and then stat F<passwd>
		1572	inside, you would write:
		1573
		1574	aio_wd "/etc", sub {
		1575	my $etcdir = shift;
		1576
		1577	# although $etcdir can be undef on error, there is generally no reason
		1578	# to check for errors here, as aio_stat will fail with ENOENT
		1579	# when $etcdir is undef.
		1580
		1581	aio_stat [$etcdir, "passwd"], sub {
		1582	# yay
		1583	};
		1584	};
		1585
		1586	The fact that C<aio_wd> is a request and not a normal function shows that
		1587	creating an IO::AIO::WD object is itself a potentially blocking operation,
		1588	which is why it is done asynchronously.
		1589
		1590	To stat the directory obtained with C<aio_wd> above, one could write
		1591	either of the following three request calls:
		1592
		1593	aio_lstat "/etc" , sub { ... # pathname as normal string
		1594	aio_lstat [$wd, "."], sub { ... # "." relative to $wd (i.e. $wd itself)
		1595	aio_lstat $wd , sub { ... # shorthand for the previous
		1596
		1597	As with normal pathnames, IO::AIO keeps a copy of the working directory
		1598	object and the pathname string, so you could write the following without
		1599	causing any issues due to C<$path> getting reused:
		1600
		1601	my $path = [$wd, undef];
		1602
		1603	for my $name (qw(abc def ghi)) {
		1604	$path->[1] = $name;
		1605	aio_stat $path, sub {
		1606	# ...
		1607	};
		1608	}
		1609
		1610	There are some caveats: when directories get renamed (or deleted), the
		1611	pathname string doesn't change, so will point to the new directory (or
		1612	nowhere at all), while the directory fd, if available on the system,
		1613	will still point to the original directory. Most functions accepting a
		1614	pathname will use the directory fd on newer systems, and the string on
		1615	older systems. Some functions (such as C<aio_realpath>) will always rely on
		1616	the string form of the pathname.
		1617
		1618	So this functionality is mainly useful to get some protection against
		1619	C<chdir>, to easily get an absolute path out of a relative path for future
		1620	reference, and to speed up doing many operations in the same directory
		1621	(e.g. when stat'ing all files in a directory).
		1622
		1623	The following functions implement this working directory abstraction:
		1624
		1625	=over 4
		1626
		1627	=item aio_wd $pathname, $callback->($wd)
		1628
		1629	Asynchonously canonicalise the given pathname and convert it to an
		1630	IO::AIO::WD object representing it. If possible and supported on the
		1631	system, also open a directory fd to speed up pathname resolution relative
		1632	to this working directory.
		1633
		1634	If something goes wrong, then C<undef> is passwd to the callback instead
		1635	of a working directory object and C<$!> is set appropriately. Since
		1636	passing C<undef> as working directory component of a pathname fails the
		1637	request with C<ENOENT>, there is often no need for error checking in the
		1638	C<aio_wd> callback, as future requests using the value will fail in the
		1639	expected way.
		1640
		1641	=item IO::AIO::CWD
		1642
		1643	This is a compiletime constant (object) that represents the process
		1644	current working directory.
		1645
		1646	Specifying this object as working directory object for a pathname is as if
		1647	the pathname would be specified directly, without a directory object. For
		1648	example, these calls are functionally identical:
		1649
		1650	aio_stat "somefile", sub { ... };
		1651	aio_stat [IO::AIO::CWD, "somefile"], sub { ... };
		1652
		1653	=back
		1654
		1655	To recover the path associated with an IO::AIO::WD object, you can use
		1656	C<aio_realpath>:
		1657
		1658	aio_realpath $wd, sub {
		1659	warn "path is $_[0]\n";
		1660	};
		1661
		1662	Currently, C<aio_statvfs> always, and C<aio_rename> and C<aio_rmdir>
		1663	sometimes, fall back to using an absolue path.
1253		1664
1254	=head2 IO::AIO::REQ CLASS	1665	=head2 IO::AIO::REQ CLASS
1255		1666
1256	All non-aggregate C<aio_*> functions return an object of this class when	1667	All non-aggregate C<aio_*> functions return an object of this class when
1257	called in non-void context.	1668	called in non-void context.
…		…
1375		1786
1376	Sets a feeder/generator on this group: every group can have an attached	1787	Sets a feeder/generator on this group: every group can have an attached
1377	generator that generates requests if idle. The idea behind this is that,	1788	generator that generates requests if idle. The idea behind this is that,
1378	although you could just queue as many requests as you want in a group,	1789	although you could just queue as many requests as you want in a group,
1379	this might starve other requests for a potentially long time. For example,	1790	this might starve other requests for a potentially long time. For example,
1380	C<aio_scandir> might generate hundreds of thousands C<aio_stat> requests,	1791	C<aio_scandir> might generate hundreds of thousands of C<aio_stat>
1381	delaying any later requests for a long time.	1792	requests, delaying any later requests for a long time.
1382		1793
1383	To avoid this, and allow incremental generation of requests, you can	1794	To avoid this, and allow incremental generation of requests, you can
1384	instead a group and set a feeder on it that generates those requests. The	1795	instead a group and set a feeder on it that generates those requests. The
1385	feed callback will be called whenever there are few enough (see C<limit>,	1796	feed callback will be called whenever there are few enough (see C<limit>,
1386	below) requests active in the group itself and is expected to queue more	1797	below) requests active in the group itself and is expected to queue more
…		…
1435		1846
1436	See C<poll_cb> for an example.	1847	See C<poll_cb> for an example.
1437		1848
1438	=item IO::AIO::poll_cb	1849	=item IO::AIO::poll_cb
1439		1850
1440	Process some outstanding events on the result pipe. You have to call	1851	Process some requests that have reached the result phase (i.e. they have
		1852	been executed but the results are not yet reported). You have to call
		1853	this "regularly" to finish outstanding requests.
		1854
1441	this regularly. Returns C<0> if all events could be processed (or there	1855	Returns C<0> if all events could be processed (or there were no
1442	were no events to process), or C<-1> if it returned earlier for whatever	1856	events to process), or C<-1> if it returned earlier for whatever
1443	reason. Returns immediately when no events are outstanding. The amount of	1857	reason. Returns immediately when no events are outstanding. The amount
1444	events processed depends on the settings of C<IO::AIO::max_poll_req> and	1858	of events processed depends on the settings of C<IO::AIO::max_poll_req>,
1445	C<IO::AIO::max_poll_time>.	1859	C<IO::AIO::max_poll_time> and C<IO::AIO::max_outstanding>.
1446		1860
1447	If not all requests were processed for whatever reason, the filehandle	1861	If not all requests were processed for whatever reason, the poll file
1448	will still be ready when C<poll_cb> returns, so normally you don't have to	1862	descriptor will still be ready when C<poll_cb> returns, so normally you
1449	do anything special to have it called later.	1863	don't have to do anything special to have it called later.
1450		1864
1451	Apart from calling C<IO::AIO::poll_cb> when the event filehandle becomes	1865	Apart from calling C<IO::AIO::poll_cb> when the event filehandle becomes
1452	ready, it can be beneficial to call this function from loops which submit	1866	ready, it can be beneficial to call this function from loops which submit
1453	a lot of requests, to make sure the results get processed when they become	1867	a lot of requests, to make sure the results get processed when they become
1454	available and not just when the loop is finished and the event loop takes	1868	available and not just when the loop is finished and the event loop takes
…		…
1463	poll => 'r', async => 1,	1877	poll => 'r', async => 1,
1464	cb => \&IO::AIO::poll_cb);	1878	cb => \&IO::AIO::poll_cb);
1465		1879
1466	=item IO::AIO::poll_wait	1880	=item IO::AIO::poll_wait
1467		1881
1468	If there are any outstanding requests and none of them in the result	1882	Wait until either at least one request is in the result phase or no
1469	phase, wait till the result filehandle becomes ready for reading (simply	1883	requests are outstanding anymore.
1470	does a C<select> on the filehandle. This is useful if you want to	1884
1471	synchronously wait for some requests to finish).	1885	This is useful if you want to synchronously wait for some requests to
		1886	become ready, without actually handling them.
1472		1887
1473	See C<nreqs> for an example.	1888	See C<nreqs> for an example.
1474		1889
1475	=item IO::AIO::poll	1890	=item IO::AIO::poll
1476		1891
…		…
1597		2012
1598	This is a very bad function to use in interactive programs because it	2013	This is a very bad function to use in interactive programs because it
1599	blocks, and a bad way to reduce concurrency because it is inexact: Better	2014	blocks, and a bad way to reduce concurrency because it is inexact: Better
1600	use an C<aio_group> together with a feed callback.	2015	use an C<aio_group> together with a feed callback.
1601		2016
1602	It's main use is in scripts without an event loop - when you want to stat	2017	Its main use is in scripts without an event loop - when you want to stat
1603	a lot of files, you can write somehting like this:	2018	a lot of files, you can write something like this:
1604		2019
1605	IO::AIO::max_outstanding 32;	2020	IO::AIO::max_outstanding 32;
1606		2021
1607	for my $path (...) {	2022	for my $path (...) {
1608	aio_stat $path , ...;	2023	aio_stat $path , ...;
…		…
1647		2062
1648	=back	2063	=back
1649		2064
1650	=head3 MISCELLANEOUS FUNCTIONS	2065	=head3 MISCELLANEOUS FUNCTIONS
1651		2066
1652	IO::AIO implements some functions that might be useful, but are not	2067	IO::AIO implements some functions that are useful when you want to use
1653	asynchronous.	2068	some "Advanced I/O" function not available to in Perl, without going the
		2069	"Asynchronous I/O" route. Many of these have an asynchronous C<aio_*>
		2070	counterpart.
1654		2071
1655	=over 4	2072	=over 4
		2073
		2074	=item $numfd = IO::AIO::get_fdlimit
		2075
		2076	This function is I<EXPERIMENTAL> and subject to change.
		2077
		2078	Tries to find the current file descriptor limit and returns it, or
		2079	C<undef> and sets C<$!> in case of an error. The limit is one larger than
		2080	the highest valid file descriptor number.
		2081
		2082	=item IO::AIO::min_fdlimit [$numfd]
		2083
		2084	This function is I<EXPERIMENTAL> and subject to change.
		2085
		2086	Try to increase the current file descriptor limit(s) to at least C<$numfd>
		2087	by changing the soft or hard file descriptor resource limit. If C<$numfd>
		2088	is missing, it will try to set a very high limit, although this is not
		2089	recommended when you know the actual minimum that you require.
		2090
		2091	If the limit cannot be raised enough, the function makes a best-effort
		2092	attempt to increase the limit as much as possible, using various
		2093	tricks, while still failing. You can query the resulting limit using
		2094	C<IO::AIO::get_fdlimit>.
		2095
		2096	If an error occurs, returns C<undef> and sets C<$!>, otherwise returns
		2097	true.
1656		2098
1657	=item IO::AIO::sendfile $ofh, $ifh, $offset, $count	2099	=item IO::AIO::sendfile $ofh, $ifh, $offset, $count
1658		2100
1659	Calls the C<eio_sendfile_sync> function, which is like C<aio_sendfile>,	2101	Calls the C<eio_sendfile_sync> function, which is like C<aio_sendfile>,
1660	but is blocking (this makes most sense if you know the input data is	2102	but is blocking (this makes most sense if you know the input data is
…		…
1665		2107
1666	=item IO::AIO::fadvise $fh, $offset, $len, $advice	2108	=item IO::AIO::fadvise $fh, $offset, $len, $advice
1667		2109
1668	Simply calls the C<posix_fadvise> function (see its	2110	Simply calls the C<posix_fadvise> function (see its
1669	manpage for details). The following advice constants are	2111	manpage for details). The following advice constants are
1670	avaiable: C<IO::AIO::FADV_NORMAL>, C<IO::AIO::FADV_SEQUENTIAL>,	2112	available: C<IO::AIO::FADV_NORMAL>, C<IO::AIO::FADV_SEQUENTIAL>,
1671	C<IO::AIO::FADV_RANDOM>, C<IO::AIO::FADV_NOREUSE>,	2113	C<IO::AIO::FADV_RANDOM>, C<IO::AIO::FADV_NOREUSE>,
1672	C<IO::AIO::FADV_WILLNEED>, C<IO::AIO::FADV_DONTNEED>.	2114	C<IO::AIO::FADV_WILLNEED>, C<IO::AIO::FADV_DONTNEED>.
1673		2115
1674	On systems that do not implement C<posix_fadvise>, this function returns	2116	On systems that do not implement C<posix_fadvise>, this function returns
1675	ENOSYS, otherwise the return value of C<posix_fadvise>.	2117	ENOSYS, otherwise the return value of C<posix_fadvise>.
1676		2118
1677	=item IO::AIO::madvise $scalar, $offset, $len, $advice	2119	=item IO::AIO::madvise $scalar, $offset, $len, $advice
1678		2120
1679	Simply calls the C<posix_madvise> function (see its	2121	Simply calls the C<posix_madvise> function (see its
1680	manpage for details). The following advice constants are	2122	manpage for details). The following advice constants are
1681	avaiable: C<IO::AIO::MADV_NORMAL>, C<IO::AIO::MADV_SEQUENTIAL>,	2123	available: C<IO::AIO::MADV_NORMAL>, C<IO::AIO::MADV_SEQUENTIAL>,
1682	C<IO::AIO::MADV_RANDOM>, C<IO::AIO::MADV_WILLNEED>, C<IO::AIO::MADV_DONTNEED>.	2124	C<IO::AIO::MADV_RANDOM>, C<IO::AIO::MADV_WILLNEED>,
		2125	C<IO::AIO::MADV_DONTNEED>.
		2126
		2127	If C<$offset> is negative, counts from the end. If C<$length> is negative,
		2128	the remaining length of the C<$scalar> is used. If possible, C<$length>
		2129	will be reduced to fit into the C<$scalar>.
1683		2130
1684	On systems that do not implement C<posix_madvise>, this function returns	2131	On systems that do not implement C<posix_madvise>, this function returns
1685	ENOSYS, otherwise the return value of C<posix_madvise>.	2132	ENOSYS, otherwise the return value of C<posix_madvise>.
1686		2133
1687	=item IO::AIO::mprotect $scalar, $offset, $len, $protect	2134	=item IO::AIO::mprotect $scalar, $offset, $len, $protect
1688		2135
1689	Simply calls the C<mprotect> function on the preferably AIO::mmap'ed	2136	Simply calls the C<mprotect> function on the preferably AIO::mmap'ed
1690	$scalar (see its manpage for details). The following protect	2137	$scalar (see its manpage for details). The following protect
1691	constants are avaiable: C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_READ>,	2138	constants are available: C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_READ>,
1692	C<IO::AIO::PROT_WRITE>, C<IO::AIO::PROT_EXEC>.	2139	C<IO::AIO::PROT_WRITE>, C<IO::AIO::PROT_EXEC>.
		2140
		2141	If C<$offset> is negative, counts from the end. If C<$length> is negative,
		2142	the remaining length of the C<$scalar> is used. If possible, C<$length>
		2143	will be reduced to fit into the C<$scalar>.
1693		2144
1694	On systems that do not implement C<mprotect>, this function returns	2145	On systems that do not implement C<mprotect>, this function returns
1695	ENOSYS, otherwise the return value of C<mprotect>.	2146	ENOSYS, otherwise the return value of C<mprotect>.
1696		2147
1697	=item IO::AIO::mmap $scalar, $length, $prot, $flags, $fh[, $offset]	2148	=item IO::AIO::mmap $scalar, $length, $prot, $flags, $fh[, $offset]
1698		2149
1699	Memory-maps a file (or anonymous memory range) and attaches it to the	2150	Memory-maps a file (or anonymous memory range) and attaches it to the
1700	given C<$scalar>, which will act like a string scalar.	2151	given C<$scalar>, which will act like a string scalar. Returns true on
		2152	success, and false otherwise.
1701		2153
		2154	The scalar must exist, but its contents do not matter - this means you
		2155	cannot use a nonexistant array or hash element. When in doubt, C<undef>
		2156	the scalar first.
		2157
1702	The only operations allowed on the scalar are C<substr>/C<vec> that don't	2158	The only operations allowed on the mmapped scalar are C<substr>/C<vec>,
1703	change the string length, and most read-only operations such as copying it	2159	which don't change the string length, and most read-only operations such
1704	or searching it with regexes and so on.	2160	as copying it or searching it with regexes and so on.
1705		2161
1706	Anything else is unsafe and will, at best, result in memory leaks.	2162	Anything else is unsafe and will, at best, result in memory leaks.
1707		2163
1708	The memory map associated with the C<$scalar> is automatically removed	2164	The memory map associated with the C<$scalar> is automatically removed
1709	when the C<$scalar> is destroyed, or when the C<IO::AIO::mmap> or	2165	when the C<$scalar> is undef'd or destroyed, or when the C<IO::AIO::mmap>
1710	C<IO::AIO::munmap> functions are called.	2166	or C<IO::AIO::munmap> functions are called on it.
1711		2167
1712	This calls the C<mmap>(2) function internally. See your system's manual	2168	This calls the C<mmap>(2) function internally. See your system's manual
1713	page for details on the C<$length>, C<$prot> and C<$flags> parameters.	2169	page for details on the C<$length>, C<$prot> and C<$flags> parameters.
1714		2170
1715	The C<$length> must be larger than zero and smaller than the actual	2171	The C<$length> must be larger than zero and smaller than the actual
1716	filesize.	2172	filesize.
1717		2173
1718	C<$prot> is a combination of C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_EXEC>,	2174	C<$prot> is a combination of C<IO::AIO::PROT_NONE>, C<IO::AIO::PROT_EXEC>,
1719	C<IO::AIO::PROT_READ> and/or C<IO::AIO::PROT_WRITE>,	2175	C<IO::AIO::PROT_READ> and/or C<IO::AIO::PROT_WRITE>,
1720		2176
1721	C<$flags> can be a combination of C<IO::AIO::MAP_SHARED> or	2177	C<$flags> can be a combination of
1722	C<IO::AIO::MAP_PRIVATE>, or a number of system-specific flags (when	2178	C<IO::AIO::MAP_SHARED> or
1723	not available, the are defined as 0): C<IO::AIO::MAP_ANONYMOUS>	2179	C<IO::AIO::MAP_PRIVATE>,
		2180	or a number of system-specific flags (when not available, the are C<0>):
1724	(which is set to C<MAP_ANON> if your system only provides this	2181	C<IO::AIO::MAP_ANONYMOUS> (which is set to C<MAP_ANON> if your system only provides this constant),
1725	constant), C<IO::AIO::MAP_HUGETLB>, C<IO::AIO::MAP_LOCKED>,	2182	C<IO::AIO::MAP_LOCKED>,
1726	C<IO::AIO::MAP_NORESERVE>, C<IO::AIO::MAP_POPULATE> or	2183	C<IO::AIO::MAP_NORESERVE>,
		2184	C<IO::AIO::MAP_POPULATE>,
1727	C<IO::AIO::MAP_NONBLOCK>	2185	C<IO::AIO::MAP_NONBLOCK>,
		2186	C<IO::AIO::MAP_FIXED>,
		2187	C<IO::AIO::MAP_GROWSDOWN>,
		2188	C<IO::AIO::MAP_32BIT>,
		2189	C<IO::AIO::MAP_HUGETLB> or
		2190	C<IO::AIO::MAP_STACK>.
1728		2191
1729	If C<$fh> is C<undef>, then a file descriptor of C<-1> is passed.	2192	If C<$fh> is C<undef>, then a file descriptor of C<-1> is passed.
1730		2193
1731	C<$offset> is the offset from the start of the file - it generally must be	2194	C<$offset> is the offset from the start of the file - it generally must be
1732	a multiple of C<IO::AIO::PAGESIZE> and defaults to C<0>.	2195	a multiple of C<IO::AIO::PAGESIZE> and defaults to C<0>.
…		…
1757		2220
1758	Calls the C<munlockall> function.	2221	Calls the C<munlockall> function.
1759		2222
1760	On systems that do not implement C<munlockall>, this function returns	2223	On systems that do not implement C<munlockall>, this function returns
1761	ENOSYS, otherwise the return value of C<munlockall>.	2224	ENOSYS, otherwise the return value of C<munlockall>.
		2225
		2226	=item IO::AIO::splice $r_fh, $r_off, $w_fh, $w_off, $length, $flags
		2227
		2228	Calls the GNU/Linux C<splice(2)> syscall, if available. If C<$r_off> or
		2229	C<$w_off> are C<undef>, then C<NULL> is passed for these, otherwise they
		2230	should be the file offset.
		2231
		2232	C<$r_fh> and C<$w_fh> should not refer to the same file, as splice might
		2233	silently corrupt the data in this case.
		2234
		2235	The following symbol flag values are available: C<IO::AIO::SPLICE_F_MOVE>,
		2236	C<IO::AIO::SPLICE_F_NONBLOCK>, C<IO::AIO::SPLICE_F_MORE> and
		2237	C<IO::AIO::SPLICE_F_GIFT>.
		2238
		2239	See the C<splice(2)> manpage for details.
		2240
		2241	=item IO::AIO::tee $r_fh, $w_fh, $length, $flags
		2242
		2243	Calls the GNU/Linux C<tee(2)> syscall, see its manpage and the
		2244	description for C<IO::AIO::splice> above for details.
		2245
		2246	=item $actual_size = IO::AIO::pipesize $r_fh[, $new_size]
		2247
		2248	Attempts to query or change the pipe buffer size. Obviously works only
		2249	on pipes, and currently works only on GNU/Linux systems, and fails with
		2250	C<-1>/C<ENOSYS> everywhere else. If anybody knows how to influence pipe buffer
		2251	size on other systems, drop me a note.
		2252
		2253	=item ($rfh, $wfh) = IO::AIO::pipe2 [$flags]
		2254
		2255	This is a direct interface to the Linux L<pipe2(2)> system call. If
		2256	C<$flags> is missing or C<0>, then this should be the same as a call to
		2257	perl's built-in C<pipe> function and create a new pipe, and works on
		2258	systems that lack the pipe2 syscall. On win32, this case invokes C<_pipe
		2259	(..., 4096, O_BINARY)>.
		2260
		2261	If C<$flags> is non-zero, it tries to invoke the pipe2 system call with
		2262	the given flags (Linux 2.6.27, glibc 2.9).
		2263
		2264	On success, the read and write file handles are returned.
		2265
		2266	On error, nothing will be returned. If the pipe2 syscall is missing and
		2267	C<$flags> is non-zero, fails with C<ENOSYS>.
		2268
		2269	Please refer to L<pipe2(2)> for more info on the C<$flags>, but at the
		2270	time of this writing, C<IO::AIO::O_CLOEXEC>, C<IO::AIO::O_NONBLOCK> and
		2271	C<IO::AIO::O_DIRECT> (Linux 3.4, for packet-based pipes) were supported.
1762		2272
1763	=back	2273	=back
1764		2274
1765	=cut	2275	=cut
1766		2276
…		…
1821		2331
1822	=over 4	2332	=over 4
1823		2333
1824	=item IO::AIO::reinit	2334	=item IO::AIO::reinit
1825		2335
1826	Abondons all current requests and I/O threads and simply reinitialises all	2336	Abandons all current requests and I/O threads and simply reinitialises all
1827	data structures. This is not an operation suppported by any standards, but	2337	data structures. This is not an operation supported by any standards, but
1828	happens to work on GNU/Linux and some newer BSD systems.	2338	happens to work on GNU/Linux and some newer BSD systems.
1829		2339
1830	The only reasonable use for this function is to call it after forking, if	2340	The only reasonable use for this function is to call it after forking, if
1831	C<IO::AIO> was used in the parent. Calling it while IO::AIO is active in	2341	C<IO::AIO> was used in the parent. Calling it while IO::AIO is active in
1832	the process will result in undefined behaviour. Calling it at any time	2342	the process will result in undefined behaviour. Calling it at any time

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Comparing IO-AIO/AIO.pm (file contents): Revision 1.204 by root, Mon Jul 18 02:02:26 2011 UTC vs. Revision 1.278 by root, Sun Oct 1 07:24:34 2017 UTC

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Comparing IO-AIO/AIO.pm (file contents):
Revision 1.204 by root, Mon Jul 18 02:02:26 2011 UTC vs.
Revision 1.278 by root, Sun Oct 1 07:24:34 2017 UTC