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

Comparing IO-AIO/AIO.pm (file contents):
Revision 1.107 by root, Fri Jun 1 05:52:59 2007 UTC vs.
Revision 1.171 by root, Sat Jan 2 14:24:32 2010 UTC

…		…
26	$req->cancel; # cancel request if still in queue	26	$req->cancel; # cancel request if still in queue
27		27
28	my $grp = aio_group sub { print "all stats done\n" };	28	my $grp = aio_group sub { print "all stats done\n" };
29	add $grp aio_stat "..." for ...;	29	add $grp aio_stat "..." for ...;
30		30
		31	# AnyEvent integration (EV, Event, Glib, Tk, POE, urxvt, pureperl...)
		32	use AnyEvent::AIO;
		33
31	# AnyEvent integration	34	# EV integration
32	open my $fh, "<&=" . IO::AIO::poll_fileno or die "$!";	35	my $aio_w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb;
33	my $w = AnyEvent->io (fh => $fh, poll => 'r', cb => sub { IO::AIO::poll_cb });
34		36
35	# Event integration	37	# Event integration
36	Event->io (fd => IO::AIO::poll_fileno,	38	Event->io (fd => IO::AIO::poll_fileno,
37	poll => 'r',	39	poll => 'r',
38	cb => \&IO::AIO::poll_cb);	40	cb => \&IO::AIO::poll_cb);
…		…
50	\&IO::AIO::poll_cb);	52	\&IO::AIO::poll_cb);
51		53
52	=head1 DESCRIPTION	54	=head1 DESCRIPTION
53		55
54	This module implements asynchronous I/O using whatever means your	56	This module implements asynchronous I/O using whatever means your
55	operating system supports.	57	operating system supports. It is implemented as an interface to C<libeio>
		58	(L<http://software.schmorp.de/pkg/libeio.html>).
56		59
57	Asynchronous means that operations that can normally block your program	60	Asynchronous means that operations that can normally block your program
58	(e.g. reading from disk) will be done asynchronously: the operation	61	(e.g. reading from disk) will be done asynchronously: the operation
59	will still block, but you can do something else in the meantime. This	62	will still block, but you can do something else in the meantime. This
60	is extremely useful for programs that need to stay interactive even	63	is extremely useful for programs that need to stay interactive even
…		…
62	etc.), but can also be used to easily do operations in parallel that are	65	etc.), but can also be used to easily do operations in parallel that are
63	normally done sequentially, e.g. stat'ing many files, which is much faster	66	normally done sequentially, e.g. stat'ing many files, which is much faster
64	on a RAID volume or over NFS when you do a number of stat operations	67	on a RAID volume or over NFS when you do a number of stat operations
65	concurrently.	68	concurrently.
66		69
67	While most of this works on all types of file descriptors (for example	70	While most of this works on all types of file descriptors (for
68	sockets), using these functions on file descriptors that support	71	example sockets), using these functions on file descriptors that
69	nonblocking operation (again, sockets, pipes etc.) is very inefficient or	72	support nonblocking operation (again, sockets, pipes etc.) is
70	might not work (aio_read fails on sockets/pipes/fifos). Use an event loop	73	very inefficient. Use an event loop for that (such as the L<EV>
71	for that (such as the L<Event\|Event> module): IO::AIO will naturally fit	74	module): IO::AIO will naturally fit into such an event loop itself.
72	into such an event loop itself.
73		75
74	In this version, a number of threads are started that execute your	76	In this version, a number of threads are started that execute your
75	requests and signal their completion. You don't need thread support	77	requests and signal their completion. You don't need thread support
76	in perl, and the threads created by this module will not be visible	78	in perl, and the threads created by this module will not be visible
77	to perl. In the future, this module might make use of the native aio	79	to perl. In the future, this module might make use of the native aio
…		…
79	not well-supported or restricted (GNU/Linux doesn't allow them on normal	81	not well-supported or restricted (GNU/Linux doesn't allow them on normal
80	files currently, for example), and they would only support aio_read and	82	files currently, for example), and they would only support aio_read and
81	aio_write, so the remaining functionality would have to be implemented	83	aio_write, so the remaining functionality would have to be implemented
82	using threads anyway.	84	using threads anyway.
83		85
84	Although the module will work with in the presence of other (Perl-)	86	Although the module will work in the presence of other (Perl-) threads,
85	threads, it is currently not reentrant in any way, so use appropriate	87	it is currently not reentrant in any way, so use appropriate locking
86	locking yourself, always call C<poll_cb> from within the same thread, or	88	yourself, always call C<poll_cb> from within the same thread, or never
87	never call C<poll_cb> (or other C<aio_> functions) recursively.	89	call C<poll_cb> (or other C<aio_> functions) recursively.
88		90
89	=head2 EXAMPLE	91	=head2 EXAMPLE
90		92
91	This is a simple example that uses the Event module and loads	93	This is a simple example that uses the EV module and loads
92	F</etc/passwd> asynchronously:	94	F</etc/passwd> asynchronously:
93		95
94	use Fcntl;	96	use Fcntl;
95	use Event;	97	use EV;
96	use IO::AIO;	98	use IO::AIO;
97		99
98	# register the IO::AIO callback with Event	100	# register the IO::AIO callback with EV
99	Event->io (fd => IO::AIO::poll_fileno,	101	my $aio_w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb;
100	poll => 'r',
101	cb => \&IO::AIO::poll_cb);
102		102
103	# queue the request to open /etc/passwd	103	# queue the request to open /etc/passwd
104	aio_open "/etc/passwd", O_RDONLY, 0, sub {	104	aio_open "/etc/passwd", O_RDONLY, 0, sub {
105	my $fh = shift	105	my $fh = shift
106	or die "error while opening: $!";	106	or die "error while opening: $!";
…		…
118		118
119	# file contents now in $contents	119	# file contents now in $contents
120	print $contents;	120	print $contents;
121		121
122	# exit event loop and program	122	# exit event loop and program
123	Event::unloop;	123	EV::unloop;
124	};	124	};
125	};	125	};
126		126
127	# possibly queue up other requests, or open GUI windows,	127	# possibly queue up other requests, or open GUI windows,
128	# check for sockets etc. etc.	128	# check for sockets etc. etc.
129		129
130	# process events as long as there are some:	130	# process events as long as there are some:
131	Event::loop;	131	EV::loop;
132		132
133	=head1 REQUEST ANATOMY AND LIFETIME	133	=head1 REQUEST ANATOMY AND LIFETIME
134		134
135	Every C<aio_*> function creates a request. which is a C data structure not	135	Every C<aio_*> function creates a request. which is a C data structure not
136	directly visible to Perl.	136	directly visible to Perl.
…		…
184		184
185	=cut	185	=cut
186		186
187	package IO::AIO;	187	package IO::AIO;
188		188
189	no warnings;	189	use Carp ();
190	use strict 'vars';	190
		191	use common::sense;
191		192
192	use base 'Exporter';	193	use base 'Exporter';
193		194
194	BEGIN {	195	BEGIN {
195	our $VERSION = '2.4';	196	our $VERSION = '3.4';
196		197
197	our @AIO_REQ = qw(aio_sendfile aio_read aio_write aio_open aio_close aio_stat	198	our @AIO_REQ = qw(aio_sendfile aio_read aio_write aio_open aio_close
198	aio_lstat aio_unlink aio_rmdir aio_readdir aio_scandir aio_symlink	199	aio_stat aio_lstat aio_unlink aio_rmdir aio_readdir aio_readdirx
199	aio_readlink aio_fsync aio_fdatasync aio_readahead aio_rename aio_link	200	aio_scandir aio_symlink aio_readlink aio_sync aio_fsync
		201	aio_fdatasync aio_sync_file_range aio_pathsync aio_readahead
		202	aio_rename aio_link aio_move aio_copy aio_group
200	aio_move aio_copy aio_group aio_nop aio_mknod aio_load aio_rmtree aio_mkdir	203	aio_nop aio_mknod aio_load aio_rmtree aio_mkdir aio_chown
201	aio_chown aio_chmod aio_utime);	204	aio_chmod aio_utime aio_truncate
		205	aio_msync aio_mtouch);
		206
202	our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice aio_block));	207	our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice));
203	our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush	208	our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush
204	min_parallel max_parallel max_idle	209	min_parallel max_parallel max_idle
205	nreqs nready npending nthreads	210	nreqs nready npending nthreads
206	max_poll_time max_poll_reqs);	211	max_poll_time max_poll_reqs
		212	sendfile fadvise);
		213
		214	push @AIO_REQ, qw(aio_busy); # not exported
207		215
208	@IO::AIO::GRP::ISA = 'IO::AIO::REQ';	216	@IO::AIO::GRP::ISA = 'IO::AIO::REQ';
209		217
210	require XSLoader;	218	require XSLoader;
211	XSLoader::load ("IO::AIO", $VERSION);	219	XSLoader::load ("IO::AIO", $VERSION);
…		…
218	All the C<aio_*> calls are more or less thin wrappers around the syscall	226	All the C<aio_*> calls are more or less thin wrappers around the syscall
219	with the same name (sans C<aio_>). The arguments are similar or identical,	227	with the same name (sans C<aio_>). The arguments are similar or identical,
220	and they all accept an additional (and optional) C<$callback> argument	228	and they all accept an additional (and optional) C<$callback> argument
221	which must be a code reference. This code reference will get called with	229	which must be a code reference. This code reference will get called with
222	the syscall return code (e.g. most syscalls return C<-1> on error, unlike	230	the syscall return code (e.g. most syscalls return C<-1> on error, unlike
223	perl, which usually delivers "false") as it's sole argument when the given	231	perl, which usually delivers "false") as its sole argument after the given
224	syscall has been executed asynchronously.	232	syscall has been executed asynchronously.
225		233
226	All functions expecting a filehandle keep a copy of the filehandle	234	All functions expecting a filehandle keep a copy of the filehandle
227	internally until the request has finished.	235	internally until the request has finished.
228		236
…		…
242	your pathnames to the locale (or other) encoding in effect in the user	250	your pathnames to the locale (or other) encoding in effect in the user
243	environment, d) use Glib::filename_from_unicode on unicode filenames or e)	251	environment, d) use Glib::filename_from_unicode on unicode filenames or e)
244	use something else to ensure your scalar has the correct contents.	252	use something else to ensure your scalar has the correct contents.
245		253
246	This works, btw. independent of the internal UTF-8 bit, which IO::AIO	254	This works, btw. independent of the internal UTF-8 bit, which IO::AIO
247	handles correctly wether it is set or not.	255	handles correctly whether it is set or not.
248		256
249	=over 4	257	=over 4
250		258
251	=item $prev_pri = aioreq_pri [$pri]	259	=item $prev_pri = aioreq_pri [$pri]
252		260
…		…
312		320
313		321
314	=item aio_close $fh, $callback->($status)	322	=item aio_close $fh, $callback->($status)
315		323
316	Asynchronously close a file and call the callback with the result	324	Asynchronously close a file and call the callback with the result
317	code. I<WARNING:> although accepted, you should not pass in a perl	325	code.
318	filehandle here, as perl will likely close the file descriptor another
319	time when the filehandle is destroyed. Normally, you can safely call perls
320	C<close> or just let filehandles go out of scope.
321		326
322	This is supposed to be a bug in the API, so that might change. It's	327	Unfortunately, you can't do this to perl. Perl I<insists> very strongly on
323	therefore best to avoid this function.	328	closing the file descriptor associated with the filehandle itself.
324		329
		330	Therefore, C<aio_close> will not close the filehandle - instead it will
		331	use dup2 to overwrite the file descriptor with the write-end of a pipe
		332	(the pipe fd will be created on demand and will be cached).
		333
		334	Or in other words: the file descriptor will be closed, but it will not be
		335	free for reuse until the perl filehandle is closed.
		336
		337	=cut
325		338
326	=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)	339	=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
327		340
328	=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)	341	=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
329		342
330	Reads or writes C<length> bytes from the specified C<fh> and C<offset>	343	Reads or writes C<$length> bytes from or to the specified C<$fh> and
331	into the scalar given by C<data> and offset C<dataoffset> and calls the	344	C<$offset> into the scalar given by C<$data> and offset C<$dataoffset>
332	callback without the actual number of bytes read (or -1 on error, just	345	and calls the callback without the actual number of bytes read (or -1 on
333	like the syscall).	346	error, just like the syscall).
		347
		348	C<aio_read> will, like C<sysread>, shrink or grow the C<$data> scalar to
		349	offset plus the actual number of bytes read.
		350
		351	If C<$offset> is undefined, then the current file descriptor offset will
		352	be used (and updated), otherwise the file descriptor offset will not be
		353	changed by these calls.
		354
		355	If C<$length> is undefined in C<aio_write>, use the remaining length of
		356	C<$data>.
		357
		358	If C<$dataoffset> is less than zero, it will be counted from the end of
		359	C<$data>.
334		360
335	The C<$data> scalar I<MUST NOT> be modified in any way while the request	361	The C<$data> scalar I<MUST NOT> be modified in any way while the request
336	is outstanding. Modifying it can result in segfaults or WW3 (if the	362	is outstanding. Modifying it can result in segfaults or World War III (if
337	necessary/optional hardware is installed).	363	the necessary/optional hardware is installed).
338		364
339	Example: Read 15 bytes at offset 7 into scalar C<$buffer>, starting at	365	Example: Read 15 bytes at offset 7 into scalar C<$buffer>, starting at
340	offset C<0> within the scalar:	366	offset C<0> within the scalar:
341		367
342	aio_read $fh, 7, 15, $buffer, 0, sub {	368	aio_read $fh, 7, 15, $buffer, 0, sub {
…		…
355		381
356	This call tries to make use of a native C<sendfile> syscall to provide	382	This call tries to make use of a native C<sendfile> syscall to provide
357	zero-copy operation. For this to work, C<$out_fh> should refer to a	383	zero-copy operation. For this to work, C<$out_fh> should refer to a
358	socket, and C<$in_fh> should refer to mmap'able file.	384	socket, and C<$in_fh> should refer to mmap'able file.
359		385
360	If the native sendfile call fails or is not implemented, it will be	386	If a native sendfile cannot be found or it fails with C<ENOSYS>,
		387	C<ENOTSUP>, C<EOPNOTSUPP>, C<EAFNOSUPPORT>, C<EPROTOTYPE> or C<ENOTSOCK>,
361	emulated, so you can call C<aio_sendfile> on any type of filehandle	388	it will be emulated, so you can call C<aio_sendfile> on any type of
362	regardless of the limitations of the operating system.	389	filehandle regardless of the limitations of the operating system.
363		390
364	Please note, however, that C<aio_sendfile> can read more bytes from	391	Please note, however, that C<aio_sendfile> can read more bytes from
365	C<$in_fh> than are written, and there is no way to find out how many	392	C<$in_fh> than are written, and there is no way to find out how many
366	bytes have been read from C<aio_sendfile> alone, as C<aio_sendfile> only	393	bytes have been read from C<aio_sendfile> alone, as C<aio_sendfile> only
367	provides the number of bytes written to C<$out_fh>. Only if the result	394	provides the number of bytes written to C<$out_fh>. Only if the result
…		…
436	aio_chown "path", 0, -1;	463	aio_chown "path", 0, -1;
437	# same as above:	464	# same as above:
438	aio_chown "path", 0, undef;	465	aio_chown "path", 0, undef;
439		466
440		467
		468	=item aio_truncate $fh_or_path, $offset, $callback->($status)
		469
		470	Works like truncate(2) or ftruncate(2).
		471
		472
441	=item aio_chmod $fh_or_path, $mode, $callback->($status)	473	=item aio_chmod $fh_or_path, $mode, $callback->($status)
442		474
443	Works like perl's C<chmod> function.	475	Works like perl's C<chmod> function.
444		476
445		477
…		…
502		534
503	Unlike the POSIX call of the same name, C<aio_readdir> reads an entire	535	Unlike the POSIX call of the same name, C<aio_readdir> reads an entire
504	directory (i.e. opendir + readdir + closedir). The entries will not be	536	directory (i.e. opendir + readdir + closedir). The entries will not be
505	sorted, and will B<NOT> include the C<.> and C<..> entries.	537	sorted, and will B<NOT> include the C<.> and C<..> entries.
506		538
507	The callback a single argument which is either C<undef> or an array-ref	539	The callback is passed a single argument which is either C<undef> or an
508	with the filenames.	540	array-ref with the filenames.
		541
		542
		543	=item aio_readdirx $pathname, $flags, $callback->($entries, $flags)
		544
		545	Quite similar to C<aio_readdir>, but the C<$flags> argument allows to tune
		546	behaviour and output format. In case of an error, C<$entries> will be
		547	C<undef>.
		548
		549	The flags are a combination of the following constants, ORed together (the
		550	flags will also be passed to the callback, possibly modified):
		551
		552	=over 4
		553
		554	=item IO::AIO::READDIR_DENTS
		555
		556	When this flag is off, then the callback gets an arrayref with of names
		557	only (as with C<aio_readdir>), otherwise it gets an arrayref with
		558	C<[$name, $type, $inode]> arrayrefs, each describing a single directory
		559	entry in more detail.
		560
		561	C<$name> is the name of the entry.
		562
		563	C<$type> is one of the C<IO::AIO::DT_xxx> constants:
		564
		565	C<IO::AIO::DT_UNKNOWN>, C<IO::AIO::DT_FIFO>, C<IO::AIO::DT_CHR>, C<IO::AIO::DT_DIR>,
		566	C<IO::AIO::DT_BLK>, C<IO::AIO::DT_REG>, C<IO::AIO::DT_LNK>, C<IO::AIO::DT_SOCK>,
		567	C<IO::AIO::DT_WHT>.
		568
		569	C<IO::AIO::DT_UNKNOWN> means just that: readdir does not know. If you need to
		570	know, you have to run stat yourself. Also, for speed reasons, the C<$type>
		571	scalars are read-only: you can not modify them.
		572
		573	C<$inode> is the inode number (which might not be exact on systems with 64
		574	bit inode numbers and 32 bit perls). This field has unspecified content on
		575	systems that do not deliver the inode information.
		576
		577	=item IO::AIO::READDIR_DIRS_FIRST
		578
		579	When this flag is set, then the names will be returned in an order where
		580	likely directories come first. This is useful when you need to quickly
		581	find directories, or you want to find all directories while avoiding to
		582	stat() each entry.
		583
		584	If the system returns type information in readdir, then this is used
		585	to find directories directly. Otherwise, likely directories are files
		586	beginning with ".", or otherwise files with no dots, of which files with
		587	short names are tried first.
		588
		589	=item IO::AIO::READDIR_STAT_ORDER
		590
		591	When this flag is set, then the names will be returned in an order
		592	suitable for stat()'ing each one. That is, when you plan to stat()
		593	all files in the given directory, then the returned order will likely
		594	be fastest.
		595
		596	If both this flag and C<IO::AIO::READDIR_DIRS_FIRST> are specified, then
		597	the likely dirs come first, resulting in a less optimal stat order.
		598
		599	=item IO::AIO::READDIR_FOUND_UNKNOWN
		600
		601	This flag should not be set when calling C<aio_readdirx>. Instead, it
		602	is being set by C<aio_readdirx>, when any of the C<$type>'s found were
		603	C<IO::AIO::DT_UNKNOWN>. The absense of this flag therefore indicates that all
		604	C<$type>'s are known, which can be used to speed up some algorithms.
		605
		606	=back
509		607
510		608
511	=item aio_load $path, $data, $callback->($status)	609	=item aio_load $path, $data, $callback->($status)
512		610
513	This is a composite request that tries to fully load the given file into	611	This is a composite request that tries to fully load the given file into
514	memory. Status is the same as with aio_read.	612	memory. Status is the same as with aio_read.
515		613
516	=cut	614	=cut
517		615
518	sub aio_load($$;$) {	616	sub aio_load($$;$) {
519	aio_block {
520	my ($path, undef, $cb) = @_;	617	my ($path, undef, $cb) = @_;
521	my $data = \$_[1];	618	my $data = \$_[1];
522		619
523	my $pri = aioreq_pri;	620	my $pri = aioreq_pri;
524	my $grp = aio_group $cb;	621	my $grp = aio_group $cb;
		622
		623	aioreq_pri $pri;
		624	add $grp aio_open $path, O_RDONLY, 0, sub {
		625	my $fh = shift
		626	or return $grp->result (-1);
525		627
526	aioreq_pri $pri;	628	aioreq_pri $pri;
527	add $grp aio_open $path, O_RDONLY, 0, sub {
528	my $fh = shift
529	or return $grp->result (-1);
530
531	aioreq_pri $pri;
532	add $grp aio_read $fh, 0, (-s $fh), $$data, 0, sub {	629	add $grp aio_read $fh, 0, (-s $fh), $$data, 0, sub {
533	$grp->result ($_[0]);	630	$grp->result ($_[0]);
534	};
535	};	631	};
536
537	$grp
538	}	632	};
		633
		634	$grp
539	}	635	}
540		636
541	=item aio_copy $srcpath, $dstpath, $callback->($status)	637	=item aio_copy $srcpath, $dstpath, $callback->($status)
542		638
543	Try to copy the I<file> (directories not supported as either source or	639	Try to copy the I<file> (directories not supported as either source or
544	destination) from C<$srcpath> to C<$dstpath> and call the callback with	640	destination) from C<$srcpath> to C<$dstpath> and call the callback with
545	the C<0> (error) or C<-1> ok.	641	a status of C<0> (ok) or C<-1> (error, see C<$!>).
546		642
547	This is a composite request that it creates the destination file with	643	This is a composite request that creates the destination file with
548	mode 0200 and copies the contents of the source file into it using	644	mode 0200 and copies the contents of the source file into it using
549	C<aio_sendfile>, followed by restoring atime, mtime, access mode and	645	C<aio_sendfile>, followed by restoring atime, mtime, access mode and
550	uid/gid, in that order.	646	uid/gid, in that order.
551		647
552	If an error occurs, the partial destination file will be unlinked, if	648	If an error occurs, the partial destination file will be unlinked, if
…		…
554	errors are being ignored.	650	errors are being ignored.
555		651
556	=cut	652	=cut
557		653
558	sub aio_copy($$;$) {	654	sub aio_copy($$;$) {
559	aio_block {
560	my ($src, $dst, $cb) = @_;	655	my ($src, $dst, $cb) = @_;
561		656
562	my $pri = aioreq_pri;	657	my $pri = aioreq_pri;
563	my $grp = aio_group $cb;	658	my $grp = aio_group $cb;
564		659
565	aioreq_pri $pri;	660	aioreq_pri $pri;
566	add $grp aio_open $src, O_RDONLY, 0, sub {	661	add $grp aio_open $src, O_RDONLY, 0, sub {
567	if (my $src_fh = $_[0]) {	662	if (my $src_fh = $_[0]) {
568	my @stat = stat $src_fh;	663	my @stat = stat $src_fh; # hmm, might block over nfs?
569		664
570	aioreq_pri $pri;	665	aioreq_pri $pri;
571	add $grp aio_open $dst, O_CREAT \| O_WRONLY \| O_TRUNC, 0200, sub {	666	add $grp aio_open $dst, O_CREAT \| O_WRONLY \| O_TRUNC, 0200, sub {
572	if (my $dst_fh = $_[0]) {	667	if (my $dst_fh = $_[0]) {
573	aioreq_pri $pri;	668	aioreq_pri $pri;
574	add $grp aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub {	669	add $grp aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub {
575	if ($_[0] == $stat[7]) {	670	if ($_[0] == $stat[7]) {
576	$grp->result (0);	671	$grp->result (0);
577	close $src_fh;	672	close $src_fh;
578		673
579	# those should not normally block. should. should.
580	utime $stat[8], $stat[9], $dst;
581	chmod $stat[2] & 07777, $dst_fh;
582	chown $stat[4], $stat[5], $dst_fh;
583	close $dst_fh;
584	} else {	674	my $ch = sub {
585	$grp->result (-1);
586	close $src_fh;
587	close $dst_fh;
588
589	aioreq $pri;	675	aioreq_pri $pri;
		676	add $grp aio_chmod $dst_fh, $stat[2] & 07777, sub {
		677	aioreq_pri $pri;
		678	add $grp aio_chown $dst_fh, $stat[4], $stat[5], sub {
		679	aioreq_pri $pri;
590	add $grp aio_unlink $dst;	680	add $grp aio_close $dst_fh;
		681	}
		682	};
591	}	683	};
		684
		685	aioreq_pri $pri;
		686	add $grp aio_utime $dst_fh, $stat[8], $stat[9], sub {
		687	if ($_[0] < 0 && $! == ENOSYS) {
		688	aioreq_pri $pri;
		689	add $grp aio_utime $dst, $stat[8], $stat[9], $ch;
		690	} else {
		691	$ch->();
		692	}
		693	};
		694	} else {
		695	$grp->result (-1);
		696	close $src_fh;
		697	close $dst_fh;
		698
		699	aioreq $pri;
		700	add $grp aio_unlink $dst;
592	};	701	}
593	} else {
594	$grp->result (-1);
595	}	702	};
		703	} else {
		704	$grp->result (-1);
596	},	705	}
597
598	} else {
599	$grp->result (-1);
600	}	706	},
		707
		708	} else {
		709	$grp->result (-1);
601	};	710	}
602
603	$grp
604	}	711	};
		712
		713	$grp
605	}	714	}
606		715
607	=item aio_move $srcpath, $dstpath, $callback->($status)	716	=item aio_move $srcpath, $dstpath, $callback->($status)
608		717
609	Try to move the I<file> (directories not supported as either source or	718	Try to move the I<file> (directories not supported as either source or
610	destination) from C<$srcpath> to C<$dstpath> and call the callback with	719	destination) from C<$srcpath> to C<$dstpath> and call the callback with
611	the C<0> (error) or C<-1> ok.	720	a status of C<0> (ok) or C<-1> (error, see C<$!>).
612		721
613	This is a composite request that tries to rename(2) the file first. If	722	This is a composite request that tries to rename(2) the file first; if
614	rename files with C<EXDEV>, it copies the file with C<aio_copy> and, if	723	rename fails with C<EXDEV>, it copies the file with C<aio_copy> and, if
615	that is successful, unlinking the C<$srcpath>.	724	that is successful, unlinks the C<$srcpath>.
616		725
617	=cut	726	=cut
618		727
619	sub aio_move($$;$) {	728	sub aio_move($$;$) {
620	aio_block {
621	my ($src, $dst, $cb) = @_;	729	my ($src, $dst, $cb) = @_;
622		730
623	my $pri = aioreq_pri;	731	my $pri = aioreq_pri;
624	my $grp = aio_group $cb;	732	my $grp = aio_group $cb;
625		733
626	aioreq_pri $pri;	734	aioreq_pri $pri;
627	add $grp aio_rename $src, $dst, sub {	735	add $grp aio_rename $src, $dst, sub {
628	if ($_[0] && $! == EXDEV) {	736	if ($_[0] && $! == EXDEV) {
629	aioreq_pri $pri;	737	aioreq_pri $pri;
630	add $grp aio_copy $src, $dst, sub {	738	add $grp aio_copy $src, $dst, sub {
631	$grp->result ($_[0]);
632
633	if (!$_[0]) {
634	aioreq_pri $pri;
635	add $grp aio_unlink $src;
636	}
637	};
638	} else {
639	$grp->result ($_[0]);	739	$grp->result ($_[0]);
		740
		741	if (!$_[0]) {
		742	aioreq_pri $pri;
		743	add $grp aio_unlink $src;
		744	}
640	}	745	};
		746	} else {
		747	$grp->result ($_[0]);
641	};	748	}
642
643	$grp
644	}	749	};
		750
		751	$grp
645	}	752	}
646		753
647	=item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs)	754	=item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs)
648		755
649	Scans a directory (similar to C<aio_readdir>) but additionally tries to	756	Scans a directory (similar to C<aio_readdir>) but additionally tries to
…		…
669		776
670	Implementation notes.	777	Implementation notes.
671		778
672	The C<aio_readdir> cannot be avoided, but C<stat()>'ing every entry can.	779	The C<aio_readdir> cannot be avoided, but C<stat()>'ing every entry can.
673		780
		781	If readdir returns file type information, then this is used directly to
		782	find directories.
		783
674	After reading the directory, the modification time, size etc. of the	784	Otherwise, after reading the directory, the modification time, size etc.
675	directory before and after the readdir is checked, and if they match (and	785	of the directory before and after the readdir is checked, and if they
676	isn't the current time), the link count will be used to decide how many	786	match (and isn't the current time), the link count will be used to decide
677	entries are directories (if >= 2). Otherwise, no knowledge of the number	787	how many entries are directories (if >= 2). Otherwise, no knowledge of the
678	of subdirectories will be assumed.	788	number of subdirectories will be assumed.
679		789
680	Then entries will be sorted into likely directories (everything without	790	Then entries will be sorted into likely directories a non-initial dot
681	a non-initial dot currently) and likely non-directories (everything	791	currently) and likely non-directories (see C<aio_readdirx>). Then every
682	else). Then every entry plus an appended C</.> will be C<stat>'ed,	792	entry plus an appended C</.> will be C<stat>'ed, likely directories first,
683	likely directories first. If that succeeds, it assumes that the entry	793	in order of their inode numbers. If that succeeds, it assumes that the
684	is a directory or a symlink to directory (which will be checked	794	entry is a directory or a symlink to directory (which will be checked
685	seperately). This is often faster than stat'ing the entry itself because	795	seperately). This is often faster than stat'ing the entry itself because
686	filesystems might detect the type of the entry without reading the inode	796	filesystems might detect the type of the entry without reading the inode
687	data (e.g. ext2fs filetype feature).	797	data (e.g. ext2fs filetype feature), even on systems that cannot return
		798	the filetype information on readdir.
688		799
689	If the known number of directories (link count - 2) has been reached, the	800	If the known number of directories (link count - 2) has been reached, the
690	rest of the entries is assumed to be non-directories.	801	rest of the entries is assumed to be non-directories.
691		802
692	This only works with certainty on POSIX (= UNIX) filesystems, which	803	This only works with certainty on POSIX (= UNIX) filesystems, which
…		…
697	directory counting heuristic.	808	directory counting heuristic.
698		809
699	=cut	810	=cut
700		811
701	sub aio_scandir($$;$) {	812	sub aio_scandir($$;$) {
702	aio_block {
703	my ($path, $maxreq, $cb) = @_;	813	my ($path, $maxreq, $cb) = @_;
704		814
705	my $pri = aioreq_pri;	815	my $pri = aioreq_pri;
706		816
707	my $grp = aio_group $cb;	817	my $grp = aio_group $cb;
708		818
709	$maxreq = 4 if $maxreq <= 0;	819	$maxreq = 4 if $maxreq <= 0;
710		820
711	# stat once	821	# stat once
		822	aioreq_pri $pri;
		823	add $grp aio_stat $path, sub {
		824	return $grp->result () if $_[0];
		825	my $now = time;
		826	my $hash1 = join ":", (stat _)[0,1,3,7,9];
		827
		828	# read the directory entries
712	aioreq_pri $pri;	829	aioreq_pri $pri;
713	add $grp aio_stat $path, sub {	830	add $grp aio_readdirx $path, READDIR_DIRS_FIRST, sub {
		831	my $entries = shift
714	return $grp->result () if $_[0];	832	or return $grp->result ();
715	my $now = time;
716	my $hash1 = join ":", (stat _)[0,1,3,7,9];
717		833
718	# read the directory entries	834	# stat the dir another time
719	aioreq_pri $pri;	835	aioreq_pri $pri;
720	add $grp aio_readdir $path, sub {
721	my $entries = shift
722	or return $grp->result ();
723
724	# stat the dir another time
725	aioreq_pri $pri;
726	add $grp aio_stat $path, sub {	836	add $grp aio_stat $path, sub {
727	my $hash2 = join ":", (stat _)[0,1,3,7,9];	837	my $hash2 = join ":", (stat _)[0,1,3,7,9];
728		838
729	my $ndirs;	839	my $ndirs;
730		840
731	# take the slow route if anything looks fishy	841	# take the slow route if anything looks fishy
732	if ($hash1 ne $hash2 or (stat _)[9] == $now) {	842	if ($hash1 ne $hash2 or (stat _)[9] == $now) {
733	$ndirs = -1;	843	$ndirs = -1;
734	} else {	844	} else {
735	# if nlink == 2, we are finished	845	# if nlink == 2, we are finished
736	# on non-posix-fs's, we rely on nlink < 2	846	# for non-posix-fs's, we rely on nlink < 2
737	$ndirs = (stat _)[3] - 2	847	$ndirs = (stat _)[3] - 2
738	or return $grp->result ([], $entries);	848	or return $grp->result ([], $entries);
739	}	849	}
740		850
741	# sort into likely dirs and likely nondirs
742	# dirs == files without ".", short entries first
743	$entries = [map $_->[0],
744	sort { $b->[1] cmp $a->[1] }
745	map [$_, sprintf "%s%04d", (/.\./ ? "1" : "0"), length],
746	@$entries];
747
748	my (@dirs, @nondirs);	851	my (@dirs, @nondirs);
749		852
750	my $statgrp = add $grp aio_group sub {	853	my $statgrp = add $grp aio_group sub {
751	$grp->result (\@dirs, \@nondirs);	854	$grp->result (\@dirs, \@nondirs);
752	};	855	};
753		856
754	limit $statgrp $maxreq;	857	limit $statgrp $maxreq;
755	feed $statgrp sub {	858	feed $statgrp sub {
756	return unless @$entries;	859	return unless @$entries;
757	my $entry = pop @$entries;	860	my $entry = shift @$entries;
758		861
759	aioreq_pri $pri;	862	aioreq_pri $pri;
760	add $statgrp aio_stat "$path/$entry/.", sub {	863	add $statgrp aio_stat "$path/$entry/.", sub {
761	if ($_[0] < 0) {	864	if ($_[0] < 0) {
762	push @nondirs, $entry;	865	push @nondirs, $entry;
763	} else {	866	} else {
764	# need to check for real directory	867	# need to check for real directory
765	aioreq_pri $pri;	868	aioreq_pri $pri;
766	add $statgrp aio_lstat "$path/$entry", sub {	869	add $statgrp aio_lstat "$path/$entry", sub {
767	if (-d _) {	870	if (-d _) {
768	push @dirs, $entry;	871	push @dirs, $entry;
769		872
770	unless (--$ndirs) {	873	unless (--$ndirs) {
771	push @nondirs, @$entries;	874	push @nondirs, @$entries;
772	feed $statgrp;	875	feed $statgrp;
773	}
774	} else {
775	push @nondirs, $entry;
776	}	876	}
		877	} else {
		878	push @nondirs, $entry;
777	}	879	}
778	}	880	}
779	};	881	}
780	};	882	};
781	};	883	};
782	};	884	};
783	};	885	};
784
785	$grp
786	}	886	};
		887
		888	$grp
787	}	889	}
788		890
789	=item aio_rmtree $path, $callback->($status)	891	=item aio_rmtree $path, $callback->($status)
790		892
791	Delete a directory tree starting (and including) C<$path>, return the	893	Delete a directory tree starting (and including) C<$path>, return the
…		…
795		897
796	=cut	898	=cut
797		899
798	sub aio_rmtree;	900	sub aio_rmtree;
799	sub aio_rmtree($;$) {	901	sub aio_rmtree($;$) {
800	aio_block {
801	my ($path, $cb) = @_;	902	my ($path, $cb) = @_;
802		903
803	my $pri = aioreq_pri;	904	my $pri = aioreq_pri;
804	my $grp = aio_group $cb;	905	my $grp = aio_group $cb;
805		906
806	aioreq_pri $pri;	907	aioreq_pri $pri;
807	add $grp aio_scandir $path, 0, sub {	908	add $grp aio_scandir $path, 0, sub {
808	my ($dirs, $nondirs) = @_;	909	my ($dirs, $nondirs) = @_;
809		910
810	my $dirgrp = aio_group sub {	911	my $dirgrp = aio_group sub {
811	add $grp aio_rmdir $path, sub {	912	add $grp aio_rmdir $path, sub {
812	$grp->result ($_[0]);	913	$grp->result ($_[0]);
813	};
814	};	914	};
815
816	(aioreq_pri $pri), add $dirgrp aio_rmtree "$path/$_" for @$dirs;
817	(aioreq_pri $pri), add $dirgrp aio_unlink "$path/$_" for @$nondirs;
818
819	add $grp $dirgrp;
820	};	915	};
821		916
822	$grp	917	(aioreq_pri $pri), add $dirgrp aio_rmtree "$path/$_" for @$dirs;
		918	(aioreq_pri $pri), add $dirgrp aio_unlink "$path/$_" for @$nondirs;
		919
		920	add $grp $dirgrp;
823	}	921	};
		922
		923	$grp
824	}	924	}
		925
		926	=item aio_sync $callback->($status)
		927
		928	Asynchronously call sync and call the callback when finished.
825		929
826	=item aio_fsync $fh, $callback->($status)	930	=item aio_fsync $fh, $callback->($status)
827		931
828	Asynchronously call fsync on the given filehandle and call the callback	932	Asynchronously call fsync on the given filehandle and call the callback
829	with the fsync result code.	933	with the fsync result code.
…		…
833	Asynchronously call fdatasync on the given filehandle and call the	937	Asynchronously call fdatasync on the given filehandle and call the
834	callback with the fdatasync result code.	938	callback with the fdatasync result code.
835		939
836	If this call isn't available because your OS lacks it or it couldn't be	940	If this call isn't available because your OS lacks it or it couldn't be
837	detected, it will be emulated by calling C<fsync> instead.	941	detected, it will be emulated by calling C<fsync> instead.
		942
		943	=item aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status)
		944
		945	Sync the data portion of the file specified by C<$offset> and C<$length>
		946	to disk (but NOT the metadata), by calling the Linux-specific
		947	sync_file_range call. If sync_file_range is not available or it returns
		948	ENOSYS, then fdatasync or fsync is being substituted.
		949
		950	C<$flags> can be a combination of C<IO::AIO::SYNC_FILE_RANGE_WAIT_BEFORE>,
		951	C<IO::AIO::SYNC_FILE_RANGE_WRITE> and
		952	C<IO::AIO::SYNC_FILE_RANGE_WAIT_AFTER>: refer to the sync_file_range
		953	manpage for details.
		954
		955	=item aio_pathsync $path, $callback->($status)
		956
		957	This request tries to open, fsync and close the given path. This is a
		958	composite request intended to sync directories after directory operations
		959	(E.g. rename). This might not work on all operating systems or have any
		960	specific effect, but usually it makes sure that directory changes get
		961	written to disc. It works for anything that can be opened for read-only,
		962	not just directories.
		963
		964	Future versions of this function might fall back to other methods when
		965	C<fsync> on the directory fails (such as calling C<sync>).
		966
		967	Passes C<0> when everything went ok, and C<-1> on error.
		968
		969	=cut
		970
		971	sub aio_pathsync($;$) {
		972	my ($path, $cb) = @_;
		973
		974	my $pri = aioreq_pri;
		975	my $grp = aio_group $cb;
		976
		977	aioreq_pri $pri;
		978	add $grp aio_open $path, O_RDONLY, 0, sub {
		979	my ($fh) = @_;
		980	if ($fh) {
		981	aioreq_pri $pri;
		982	add $grp aio_fsync $fh, sub {
		983	$grp->result ($_[0]);
		984
		985	aioreq_pri $pri;
		986	add $grp aio_close $fh;
		987	};
		988	} else {
		989	$grp->result (-1);
		990	}
		991	};
		992
		993	$grp
		994	}
		995
		996	=item aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
		997
		998	This is a rather advanced IO::AIO call, which only works on mmap(2)ed
		999	scalars (see the L<Sys::Mmap> or L<Mmap> modules for details on this, note
		1000	that the scalar must only be modified in-place while an aio operation is
		1001	pending on it).
		1002
		1003	It calls the C<msync> function of your OS, if available, with the memory
		1004	area starting at C<$offset> in the string and ending C<$length> bytes
		1005	later. If C<$length> is negative, counts from the end, and if C<$length>
		1006	is C<undef>, then it goes till the end of the string. The flags can be
		1007	a combination of C<IO::AIO::MS_ASYNC>, C<IO::AIO::MS_INVALIDATE> and
		1008	C<IO::AIO::MS_SYNC>.
		1009
		1010	=item aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
		1011
		1012	This is a rather advanced IO::AIO call, which works best on mmap(2)ed
		1013	scalars.
		1014
		1015	It touches (reads or writes) all memory pages in the specified
		1016	range inside the scalar. All caveats and parameters are the same
		1017	as for C<aio_msync>, above, except for flags, which must be either
		1018	C<0> (which reads all pages and ensures they are instantiated) or
		1019	C<IO::AIO::MT_MODIFY>, which modifies the memory page s(by reading and
		1020	writing an octet from it, which dirties the page).
838		1021
839	=item aio_group $callback->(...)	1022	=item aio_group $callback->(...)
840		1023
841	This is a very special aio request: Instead of doing something, it is a	1024	This is a very special aio request: Instead of doing something, it is a
842	container for other aio requests, which is useful if you want to bundle	1025	container for other aio requests, which is useful if you want to bundle
…		…
892	=item cancel $req	1075	=item cancel $req
893		1076
894	Cancels the request, if possible. Has the effect of skipping execution	1077	Cancels the request, if possible. Has the effect of skipping execution
895	when entering the B<execute> state and skipping calling the callback when	1078	when entering the B<execute> state and skipping calling the callback when
896	entering the the B<result> state, but will leave the request otherwise	1079	entering the the B<result> state, but will leave the request otherwise
897	untouched. That means that requests that currently execute will not be	1080	untouched (with the exception of readdir). That means that requests that
898	stopped and resources held by the request will not be freed prematurely.	1081	currently execute will not be stopped and resources held by the request
		1082	will not be freed prematurely.
899		1083
900	=item cb $req $callback->(...)	1084	=item cb $req $callback->(...)
901		1085
902	Replace (or simply set) the callback registered to the request.	1086	Replace (or simply set) the callback registered to the request.
903		1087
…		…
954	Their lifetime, simplified, looks like this: when they are empty, they	1138	Their lifetime, simplified, looks like this: when they are empty, they
955	will finish very quickly. If they contain only requests that are in the	1139	will finish very quickly. If they contain only requests that are in the
956	C<done> state, they will also finish. Otherwise they will continue to	1140	C<done> state, they will also finish. Otherwise they will continue to
957	exist.	1141	exist.
958		1142
959	That means after creating a group you have some time to add requests. And	1143	That means after creating a group you have some time to add requests
960	in the callbacks of those requests, you can add further requests to the	1144	(precisely before the callback has been invoked, which is only done within
961	group. And only when all those requests have finished will the the group	1145	the C<poll_cb>). And in the callbacks of those requests, you can add
962	itself finish.	1146	further requests to the group. And only when all those requests have
		1147	finished will the the group itself finish.
963		1148
964	=over 4	1149	=over 4
965		1150
966	=item add $grp ...	1151	=item add $grp ...
967		1152
…		…
976	=item $grp->cancel_subs	1161	=item $grp->cancel_subs
977		1162
978	Cancel all subrequests and clears any feeder, but not the group request	1163	Cancel all subrequests and clears any feeder, but not the group request
979	itself. Useful when you queued a lot of events but got a result early.	1164	itself. Useful when you queued a lot of events but got a result early.
980		1165
		1166	The group request will finish normally (you cannot add requests to the
		1167	group).
		1168
981	=item $grp->result (...)	1169	=item $grp->result (...)
982		1170
983	Set the result value(s) that will be passed to the group callback when all	1171	Set the result value(s) that will be passed to the group callback when all
984	subrequests have finished and set thre groups errno to the current value	1172	subrequests have finished and set the groups errno to the current value
985	of errno (just like calling C<errno> without an error number). By default,	1173	of errno (just like calling C<errno> without an error number). By default,
986	no argument will be passed and errno is zero.	1174	no argument will be passed and errno is zero.
987		1175
988	=item $grp->errno ([$errno])	1176	=item $grp->errno ([$errno])
989		1177
…		…
1000	=item feed $grp $callback->($grp)	1188	=item feed $grp $callback->($grp)
1001		1189
1002	Sets a feeder/generator on this group: every group can have an attached	1190	Sets a feeder/generator on this group: every group can have an attached
1003	generator that generates requests if idle. The idea behind this is that,	1191	generator that generates requests if idle. The idea behind this is that,
1004	although you could just queue as many requests as you want in a group,	1192	although you could just queue as many requests as you want in a group,
1005	this might starve other requests for a potentially long time. For	1193	this might starve other requests for a potentially long time. For example,
1006	example, C<aio_scandir> might generate hundreds of thousands C<aio_stat>	1194	C<aio_scandir> might generate hundreds of thousands C<aio_stat> requests,
1007	requests, delaying any later requests for a long time.	1195	delaying any later requests for a long time.
1008		1196
1009	To avoid this, and allow incremental generation of requests, you can	1197	To avoid this, and allow incremental generation of requests, you can
1010	instead a group and set a feeder on it that generates those requests. The	1198	instead a group and set a feeder on it that generates those requests. The
1011	feed callback will be called whenever there are few enough (see C<limit>,	1199	feed callback will be called whenever there are few enough (see C<limit>,
1012	below) requests active in the group itself and is expected to queue more	1200	below) requests active in the group itself and is expected to queue more
…		…
1016	not impose any limits).	1204	not impose any limits).
1017		1205
1018	If the feed does not queue more requests when called, it will be	1206	If the feed does not queue more requests when called, it will be
1019	automatically removed from the group.	1207	automatically removed from the group.
1020		1208
1021	If the feed limit is C<0>, it will be set to C<2> automatically.	1209	If the feed limit is C<0> when this method is called, it will be set to
		1210	C<2> automatically.
1022		1211
1023	Example:	1212	Example:
1024		1213
1025	# stat all files in @files, but only ever use four aio requests concurrently:	1214	# stat all files in @files, but only ever use four aio requests concurrently:
1026		1215
…		…
1038	Sets the feeder limit for the group: The feeder will be called whenever	1227	Sets the feeder limit for the group: The feeder will be called whenever
1039	the group contains less than this many requests.	1228	the group contains less than this many requests.
1040		1229
1041	Setting the limit to C<0> will pause the feeding process.	1230	Setting the limit to C<0> will pause the feeding process.
1042		1231
		1232	The default value for the limit is C<0>, but note that setting a feeder
		1233	automatically bumps it up to C<2>.
		1234
1043	=back	1235	=back
1044		1236
1045	=head2 SUPPORT FUNCTIONS	1237	=head2 SUPPORT FUNCTIONS
1046		1238
1047	=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION	1239	=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION
…		…
1049	=over 4	1241	=over 4
1050		1242
1051	=item $fileno = IO::AIO::poll_fileno	1243	=item $fileno = IO::AIO::poll_fileno
1052		1244
1053	Return the I<request result pipe file descriptor>. This filehandle must be	1245	Return the I<request result pipe file descriptor>. This filehandle must be
1054	polled for reading by some mechanism outside this module (e.g. Event or	1246	polled for reading by some mechanism outside this module (e.g. EV, Glib,
1055	select, see below or the SYNOPSIS). If the pipe becomes readable you have	1247	select and so on, see below or the SYNOPSIS). If the pipe becomes readable
1056	to call C<poll_cb> to check the results.	1248	you have to call C<poll_cb> to check the results.
1057		1249
1058	See C<poll_cb> for an example.	1250	See C<poll_cb> for an example.
1059		1251
1060	=item IO::AIO::poll_cb	1252	=item IO::AIO::poll_cb
1061		1253
1062	Process some outstanding events on the result pipe. You have to call this	1254	Process some outstanding events on the result pipe. You have to call this
1063	regularly. Returns the number of events processed. Returns immediately	1255	regularly. Returns C<0> if all events could be processed, or C<-1> if it
		1256	returned earlier for whatever reason. Returns immediately when no events
1064	when no events are outstanding. The amount of events processed depends on	1257	are outstanding. The amount of events processed depends on the settings of
1065	the settings of C<IO::AIO::max_poll_req> and C<IO::AIO::max_poll_time>.	1258	C<IO::AIO::max_poll_req> and C<IO::AIO::max_poll_time>.
1066		1259
1067	If not all requests were processed for whatever reason, the filehandle	1260	If not all requests were processed for whatever reason, the filehandle
1068	will still be ready when C<poll_cb> returns.	1261	will still be ready when C<poll_cb> returns, so normally you don't have to
		1262	do anything special to have it called later.
1069		1263
1070	Example: Install an Event watcher that automatically calls	1264	Example: Install an Event watcher that automatically calls
1071	IO::AIO::poll_cb with high priority:	1265	IO::AIO::poll_cb with high priority (more examples can be found in the
		1266	SYNOPSIS section, at the top of this document):
1072		1267
1073	Event->io (fd => IO::AIO::poll_fileno,	1268	Event->io (fd => IO::AIO::poll_fileno,
1074	poll => 'r', async => 1,	1269	poll => 'r', async => 1,
1075	cb => \&IO::AIO::poll_cb);	1270	cb => \&IO::AIO::poll_cb);
1076		1271
…		…
1187		1382
1188	The default is probably ok in most situations, especially if thread	1383	The default is probably ok in most situations, especially if thread
1189	creation is fast. If thread creation is very slow on your system you might	1384	creation is fast. If thread creation is very slow on your system you might
1190	want to use larger values.	1385	want to use larger values.
1191		1386
1192	=item $oldmaxreqs = IO::AIO::max_outstanding $maxreqs	1387	=item IO::AIO::max_outstanding $maxreqs
1193		1388
1194	This is a very bad function to use in interactive programs because it	1389	This is a very bad function to use in interactive programs because it
1195	blocks, and a bad way to reduce concurrency because it is inexact: Better	1390	blocks, and a bad way to reduce concurrency because it is inexact: Better
1196	use an C<aio_group> together with a feed callback.	1391	use an C<aio_group> together with a feed callback.
1197		1392
1198	Sets the maximum number of outstanding requests to C<$nreqs>. If you	1393	Sets the maximum number of outstanding requests to C<$nreqs>. If you
1199	to queue up more than this number of requests, the next call to the	1394	do queue up more than this number of requests, the next call to the
1200	C<poll_cb> (and C<poll_some> and other functions calling C<poll_cb>)	1395	C<poll_cb> (and C<poll_some> and other functions calling C<poll_cb>)
1201	function will block until the limit is no longer exceeded.	1396	function will block until the limit is no longer exceeded.
1202		1397
1203	The default value is very large, so there is no practical limit on the	1398	The default value is very large, so there is no practical limit on the
1204	number of outstanding requests.	1399	number of outstanding requests.
1205		1400
1206	You can still queue as many requests as you want. Therefore,	1401	You can still queue as many requests as you want. Therefore,
1207	C<max_oustsanding> is mainly useful in simple scripts (with low values) or	1402	C<max_outstanding> is mainly useful in simple scripts (with low values) or
1208	as a stop gap to shield against fatal memory overflow (with large values).	1403	as a stop gap to shield against fatal memory overflow (with large values).
1209		1404
1210	=back	1405	=back
1211		1406
1212	=head3 STATISTICAL INFORMATION	1407	=head3 STATISTICAL INFORMATION
…		…
1233	Returns the number of requests currently in the pending state (executed,	1428	Returns the number of requests currently in the pending state (executed,
1234	but not yet processed by poll_cb).	1429	but not yet processed by poll_cb).
1235		1430
1236	=back	1431	=back
1237		1432
		1433	=head3 MISCELLANEOUS FUNCTIONS
		1434
		1435	IO::AIO implements some functions that might be useful, but are not
		1436	asynchronous.
		1437
		1438	=over 4
		1439
		1440	=item IO::AIO::sendfile $ofh, $ifh, $offset, $count
		1441
		1442	Calls the C<eio_sendfile_sync> function, which is like C<aio_sendfile>,
		1443	but is blocking (this makes most sense if you know the input data is
		1444	likely cached already and the output filehandle is set to non-blocking
		1445	operations).
		1446
		1447	Returns the number of bytes copied, or C<-1> on error.
		1448
		1449	=item IO::AIO::fadvise $fh, $offset, $len, $advice
		1450
		1451	Simply calls the C<posix_fadvise> function (see it's
		1452	manpage for details). The following advice constants are
		1453	avaiable: C<IO::AIO::FADV_NORMAL>, C<IO::AIO::FADV_SEQUENTIAL>,
		1454	C<IO::AIO::FADV_RANDOM>, C<IO::AIO::FADV_NOREUSE>,
		1455	C<IO::AIO::FADV_WILLNEED>, C<IO::AIO::FADV_DONTNEED>.
		1456
		1457	On systems that do not implement C<posix_fadvise>, this function returns
		1458	ENOSYS, otherwise the return value of C<posix_fadvise>.
		1459
		1460	=back
		1461
1238	=cut	1462	=cut
1239
1240	# support function to convert a fd into a perl filehandle
1241	sub _fd2fh {
1242	return undef if $_[0] < 0;
1243
1244	# try to generate nice filehandles
1245	my $sym = "IO::AIO::fd#$_[0]";
1246	local *$sym;
1247
1248	open *$sym, "+<&=$_[0]" # usually works under any unix
1249	or open *$sym, "<&=$_[0]" # cygwin needs this
1250	or open *$sym, ">&=$_[0]" # or this
1251	or return undef;
1252
1253	*$sym
1254	}
1255		1463
1256	min_parallel 8;	1464	min_parallel 8;
1257		1465
1258	END { flush }	1466	END { flush }
1259		1467
…		…
1283	bytes of memory. In addition, stat requests need a stat buffer (possibly	1491	bytes of memory. In addition, stat requests need a stat buffer (possibly
1284	a few hundred bytes), readdir requires a result buffer and so on. Perl	1492	a few hundred bytes), readdir requires a result buffer and so on. Perl
1285	scalars and other data passed into aio requests will also be locked and	1493	scalars and other data passed into aio requests will also be locked and
1286	will consume memory till the request has entered the done state.	1494	will consume memory till the request has entered the done state.
1287		1495
1288	This is now awfully much, so queuing lots of requests is not usually a	1496	This is not awfully much, so queuing lots of requests is not usually a
1289	problem.	1497	problem.
1290		1498
1291	Per-thread usage:	1499	Per-thread usage:
1292		1500
1293	In the execution phase, some aio requests require more memory for	1501	In the execution phase, some aio requests require more memory for
…		…
1298		1506
1299	Known bugs will be fixed in the next release.	1507	Known bugs will be fixed in the next release.
1300		1508
1301	=head1 SEE ALSO	1509	=head1 SEE ALSO
1302		1510
1303	L<Coro::AIO>.	1511	L<AnyEvent::AIO> for easy integration into event loops, L<Coro::AIO> for a
		1512	more natural syntax.
1304		1513
1305	=head1 AUTHOR	1514	=head1 AUTHOR
1306		1515
1307	Marc Lehmann <schmorp@schmorp.de>	1516	Marc Lehmann <schmorp@schmorp.de>
1308	http://home.schmorp.de/	1517	http://home.schmorp.de/

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Comparing IO-AIO/AIO.pm (file contents): Revision 1.107 by root, Fri Jun 1 05:52:59 2007 UTC vs. Revision 1.171 by root, Sat Jan 2 14:24:32 2010 UTC

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Comparing IO-AIO/AIO.pm (file contents):
Revision 1.107 by root, Fri Jun 1 05:52:59 2007 UTC vs.
Revision 1.171 by root, Sat Jan 2 14:24:32 2010 UTC