[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 1.164 by root, Tue Aug 18 03:26:02 2009 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 = '3.3';
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
202	our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice aio_block));	206	our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice));
203	our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush	207	our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush
204	min_parallel max_parallel max_idle	208	min_parallel max_parallel max_idle
205	nreqs nready npending nthreads	209	nreqs nready npending nthreads
206	max_poll_time max_poll_reqs);	210	max_poll_time max_poll_reqs
		211	sendfile fadvise);
		212
		213	push @AIO_REQ, qw(aio_busy); # not exported
207		214
208	@IO::AIO::GRP::ISA = 'IO::AIO::REQ';	215	@IO::AIO::GRP::ISA = 'IO::AIO::REQ';
209		216
210	require XSLoader;	217	require XSLoader;
211	XSLoader::load ("IO::AIO", $VERSION);	218	XSLoader::load ("IO::AIO", $VERSION);
…		…
218	All the C<aio_*> calls are more or less thin wrappers around the syscall	225	All the C<aio_*> calls are more or less thin wrappers around the syscall
219	with the same name (sans C<aio_>). The arguments are similar or identical,	226	with the same name (sans C<aio_>). The arguments are similar or identical,
220	and they all accept an additional (and optional) C<$callback> argument	227	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	228	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	229	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	230	perl, which usually delivers "false") as its sole argument after the given
224	syscall has been executed asynchronously.	231	syscall has been executed asynchronously.
225		232
226	All functions expecting a filehandle keep a copy of the filehandle	233	All functions expecting a filehandle keep a copy of the filehandle
227	internally until the request has finished.	234	internally until the request has finished.
228		235
…		…
242	your pathnames to the locale (or other) encoding in effect in the user	249	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)	250	environment, d) use Glib::filename_from_unicode on unicode filenames or e)
244	use something else to ensure your scalar has the correct contents.	251	use something else to ensure your scalar has the correct contents.
245		252
246	This works, btw. independent of the internal UTF-8 bit, which IO::AIO	253	This works, btw. independent of the internal UTF-8 bit, which IO::AIO
247	handles correctly wether it is set or not.	254	handles correctly whether it is set or not.
248		255
249	=over 4	256	=over 4
250		257
251	=item $prev_pri = aioreq_pri [$pri]	258	=item $prev_pri = aioreq_pri [$pri]
252		259
…		…
312		319
313		320
314	=item aio_close $fh, $callback->($status)	321	=item aio_close $fh, $callback->($status)
315		322
316	Asynchronously close a file and call the callback with the result	323	Asynchronously close a file and call the callback with the result
317	code. I<WARNING:> although accepted, you should not pass in a perl	324	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		325
322	This is supposed to be a bug in the API, so that might change. It's	326	Unfortunately, you can't do this to perl. Perl I<insists> very strongly on
323	therefore best to avoid this function.	327	closing the file descriptor associated with the filehandle itself.
324		328
		329	Therefore, C<aio_close> will not close the filehandle - instead it will
		330	use dup2 to overwrite the file descriptor with the write-end of a pipe
		331	(the pipe fd will be created on demand and will be cached).
		332
		333	Or in other words: the file descriptor will be closed, but it will not be
		334	free for reuse until the perl filehandle is closed.
		335
		336	=cut
325		337
326	=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)	338	=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
327		339
328	=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)	340	=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
329		341
330	Reads or writes C<length> bytes from the specified C<fh> and C<offset>	342	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	343	C<$offset> into the scalar given by C<$data> and offset C<$dataoffset>
332	callback without the actual number of bytes read (or -1 on error, just	344	and calls the callback without the actual number of bytes read (or -1 on
333	like the syscall).	345	error, just like the syscall).
		346
		347	C<aio_read> will, like C<sysread>, shrink or grow the C<$data> scalar to
		348	offset plus the actual number of bytes read.
		349
		350	If C<$offset> is undefined, then the current file descriptor offset will
		351	be used (and updated), otherwise the file descriptor offset will not be
		352	changed by these calls.
		353
		354	If C<$length> is undefined in C<aio_write>, use the remaining length of
		355	C<$data>.
		356
		357	If C<$dataoffset> is less than zero, it will be counted from the end of
		358	C<$data>.
334		359
335	The C<$data> scalar I<MUST NOT> be modified in any way while the request	360	The C<$data> scalar I<MUST NOT> be modified in any way while the request
336	is outstanding. Modifying it can result in segfaults or WW3 (if the	361	is outstanding. Modifying it can result in segfaults or World War III (if
337	necessary/optional hardware is installed).	362	the necessary/optional hardware is installed).
338		363
339	Example: Read 15 bytes at offset 7 into scalar C<$buffer>, starting at	364	Example: Read 15 bytes at offset 7 into scalar C<$buffer>, starting at
340	offset C<0> within the scalar:	365	offset C<0> within the scalar:
341		366
342	aio_read $fh, 7, 15, $buffer, 0, sub {	367	aio_read $fh, 7, 15, $buffer, 0, sub {
…		…
436	aio_chown "path", 0, -1;	461	aio_chown "path", 0, -1;
437	# same as above:	462	# same as above:
438	aio_chown "path", 0, undef;	463	aio_chown "path", 0, undef;
439		464
440		465
		466	=item aio_truncate $fh_or_path, $offset, $callback->($status)
		467
		468	Works like truncate(2) or ftruncate(2).
		469
		470
441	=item aio_chmod $fh_or_path, $mode, $callback->($status)	471	=item aio_chmod $fh_or_path, $mode, $callback->($status)
442		472
443	Works like perl's C<chmod> function.	473	Works like perl's C<chmod> function.
444		474
445		475
…		…
502		532
503	Unlike the POSIX call of the same name, C<aio_readdir> reads an entire	533	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	534	directory (i.e. opendir + readdir + closedir). The entries will not be
505	sorted, and will B<NOT> include the C<.> and C<..> entries.	535	sorted, and will B<NOT> include the C<.> and C<..> entries.
506		536
507	The callback a single argument which is either C<undef> or an array-ref	537	The callback is passed a single argument which is either C<undef> or an
508	with the filenames.	538	array-ref with the filenames.
		539
		540
		541	=item aio_readdirx $pathname, $flags, $callback->($entries, $flags)
		542
		543	Quite similar to C<aio_readdir>, but the C<$flags> argument allows to tune
		544	behaviour and output format. In case of an error, C<$entries> will be
		545	C<undef>.
		546
		547	The flags are a combination of the following constants, ORed together (the
		548	flags will also be passed to the callback, possibly modified):
		549
		550	=over 4
		551
		552	=item IO::AIO::READDIR_DENTS
		553
		554	When this flag is off, then the callback gets an arrayref with of names
		555	only (as with C<aio_readdir>), otherwise it gets an arrayref with
		556	C<[$name, $type, $inode]> arrayrefs, each describing a single directory
		557	entry in more detail.
		558
		559	C<$name> is the name of the entry.
		560
		561	C<$type> is one of the C<IO::AIO::DT_xxx> constants:
		562
		563	C<IO::AIO::DT_UNKNOWN>, C<IO::AIO::DT_FIFO>, C<IO::AIO::DT_CHR>, C<IO::AIO::DT_DIR>,
		564	C<IO::AIO::DT_BLK>, C<IO::AIO::DT_REG>, C<IO::AIO::DT_LNK>, C<IO::AIO::DT_SOCK>,
		565	C<IO::AIO::DT_WHT>.
		566
		567	C<IO::AIO::DT_UNKNOWN> means just that: readdir does not know. If you need to
		568	know, you have to run stat yourself. Also, for speed reasons, the C<$type>
		569	scalars are read-only: you can not modify them.
		570
		571	C<$inode> is the inode number (which might not be exact on systems with 64
		572	bit inode numbers and 32 bit perls). This field has unspecified content on
		573	systems that do not deliver the inode information.
		574
		575	=item IO::AIO::READDIR_DIRS_FIRST
		576
		577	When this flag is set, then the names will be returned in an order where
		578	likely directories come first. This is useful when you need to quickly
		579	find directories, or you want to find all directories while avoiding to
		580	stat() each entry.
		581
		582	If the system returns type information in readdir, then this is used
		583	to find directories directly. Otherwise, likely directories are files
		584	beginning with ".", or otherwise files with no dots, of which files with
		585	short names are tried first.
		586
		587	=item IO::AIO::READDIR_STAT_ORDER
		588
		589	When this flag is set, then the names will be returned in an order
		590	suitable for stat()'ing each one. That is, when you plan to stat()
		591	all files in the given directory, then the returned order will likely
		592	be fastest.
		593
		594	If both this flag and C<IO::AIO::READDIR_DIRS_FIRST> are specified, then
		595	the likely dirs come first, resulting in a less optimal stat order.
		596
		597	=item IO::AIO::READDIR_FOUND_UNKNOWN
		598
		599	This flag should not be set when calling C<aio_readdirx>. Instead, it
		600	is being set by C<aio_readdirx>, when any of the C<$type>'s found were
		601	C<IO::AIO::DT_UNKNOWN>. The absense of this flag therefore indicates that all
		602	C<$type>'s are known, which can be used to speed up some algorithms.
		603
		604	=back
509		605
510		606
511	=item aio_load $path, $data, $callback->($status)	607	=item aio_load $path, $data, $callback->($status)
512		608
513	This is a composite request that tries to fully load the given file into	609	This is a composite request that tries to fully load the given file into
514	memory. Status is the same as with aio_read.	610	memory. Status is the same as with aio_read.
515		611
516	=cut	612	=cut
517		613
518	sub aio_load($$;$) {	614	sub aio_load($$;$) {
519	aio_block {
520	my ($path, undef, $cb) = @_;	615	my ($path, undef, $cb) = @_;
521	my $data = \$_[1];	616	my $data = \$_[1];
522		617
523	my $pri = aioreq_pri;	618	my $pri = aioreq_pri;
524	my $grp = aio_group $cb;	619	my $grp = aio_group $cb;
		620
		621	aioreq_pri $pri;
		622	add $grp aio_open $path, O_RDONLY, 0, sub {
		623	my $fh = shift
		624	or return $grp->result (-1);
525		625
526	aioreq_pri $pri;	626	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), $$data, 0, sub {	627	add $grp aio_read $fh, 0, (-s $fh), $$data, 0, sub {
533	$grp->result ($_[0]);	628	$grp->result ($_[0]);
534	};
535	};	629	};
536
537	$grp
538	}	630	};
		631
		632	$grp
539	}	633	}
540		634
541	=item aio_copy $srcpath, $dstpath, $callback->($status)	635	=item aio_copy $srcpath, $dstpath, $callback->($status)
542		636
543	Try to copy the I<file> (directories not supported as either source or	637	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	638	destination) from C<$srcpath> to C<$dstpath> and call the callback with
545	the C<0> (error) or C<-1> ok.	639	a status of C<0> (error) or C<-1> (ok).
546		640
547	This is a composite request that it creates the destination file with	641	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	642	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	643	C<aio_sendfile>, followed by restoring atime, mtime, access mode and
550	uid/gid, in that order.	644	uid/gid, in that order.
551		645
552	If an error occurs, the partial destination file will be unlinked, if	646	If an error occurs, the partial destination file will be unlinked, if
…		…
554	errors are being ignored.	648	errors are being ignored.
555		649
556	=cut	650	=cut
557		651
558	sub aio_copy($$;$) {	652	sub aio_copy($$;$) {
559	aio_block {
560	my ($src, $dst, $cb) = @_;	653	my ($src, $dst, $cb) = @_;
561		654
562	my $pri = aioreq_pri;	655	my $pri = aioreq_pri;
563	my $grp = aio_group $cb;	656	my $grp = aio_group $cb;
564		657
565	aioreq_pri $pri;	658	aioreq_pri $pri;
566	add $grp aio_open $src, O_RDONLY, 0, sub {	659	add $grp aio_open $src, O_RDONLY, 0, sub {
567	if (my $src_fh = $_[0]) {	660	if (my $src_fh = $_[0]) {
568	my @stat = stat $src_fh;	661	my @stat = stat $src_fh; # hmm, might bock over nfs?
569		662
570	aioreq_pri $pri;	663	aioreq_pri $pri;
571	add $grp aio_open $dst, O_CREAT \| O_WRONLY \| O_TRUNC, 0200, sub {	664	add $grp aio_open $dst, O_CREAT \| O_WRONLY \| O_TRUNC, 0200, sub {
572	if (my $dst_fh = $_[0]) {	665	if (my $dst_fh = $_[0]) {
573	aioreq_pri $pri;	666	aioreq_pri $pri;
574	add $grp aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub {	667	add $grp aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub {
575	if ($_[0] == $stat[7]) {	668	if ($_[0] == $stat[7]) {
576	$grp->result (0);	669	$grp->result (0);
577	close $src_fh;	670	close $src_fh;
578		671
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 {	672	my $ch = sub {
585	$grp->result (-1);
586	close $src_fh;
587	close $dst_fh;
588
589	aioreq $pri;	673	aioreq_pri $pri;
		674	add $grp aio_chmod $dst_fh, $stat[2] & 07777, sub {
		675	aioreq_pri $pri;
		676	add $grp aio_chown $dst_fh, $stat[4], $stat[5], sub {
		677	aioreq_pri $pri;
590	add $grp aio_unlink $dst;	678	add $grp aio_close $dst_fh;
		679	}
		680	};
591	}	681	};
		682
		683	aioreq_pri $pri;
		684	add $grp aio_utime $dst_fh, $stat[8], $stat[9], sub {
		685	if ($_[0] < 0 && $! == ENOSYS) {
		686	aioreq_pri $pri;
		687	add $grp aio_utime $dst, $stat[8], $stat[9], $ch;
		688	} else {
		689	$ch->();
		690	}
		691	};
		692	} else {
		693	$grp->result (-1);
		694	close $src_fh;
		695	close $dst_fh;
		696
		697	aioreq $pri;
		698	add $grp aio_unlink $dst;
592	};	699	}
593	} else {
594	$grp->result (-1);
595	}	700	};
		701	} else {
		702	$grp->result (-1);
596	},	703	}
597
598	} else {
599	$grp->result (-1);
600	}	704	},
		705
		706	} else {
		707	$grp->result (-1);
601	};	708	}
602
603	$grp
604	}	709	};
		710
		711	$grp
605	}	712	}
606		713
607	=item aio_move $srcpath, $dstpath, $callback->($status)	714	=item aio_move $srcpath, $dstpath, $callback->($status)
608		715
609	Try to move the I<file> (directories not supported as either source or	716	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	717	destination) from C<$srcpath> to C<$dstpath> and call the callback with
611	the C<0> (error) or C<-1> ok.	718	the status C<0> (error) or C<-1> (ok).
612		719
613	This is a composite request that tries to rename(2) the file first. If	720	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	721	rename fails with C<EXDEV>, it copies the file with C<aio_copy> and, if
615	that is successful, unlinking the C<$srcpath>.	722	that is successful, unlinks the C<$srcpath>.
616		723
617	=cut	724	=cut
618		725
619	sub aio_move($$;$) {	726	sub aio_move($$;$) {
620	aio_block {
621	my ($src, $dst, $cb) = @_;	727	my ($src, $dst, $cb) = @_;
622		728
623	my $pri = aioreq_pri;	729	my $pri = aioreq_pri;
624	my $grp = aio_group $cb;	730	my $grp = aio_group $cb;
625		731
626	aioreq_pri $pri;	732	aioreq_pri $pri;
627	add $grp aio_rename $src, $dst, sub {	733	add $grp aio_rename $src, $dst, sub {
628	if ($_[0] && $! == EXDEV) {	734	if ($_[0] && $! == EXDEV) {
629	aioreq_pri $pri;	735	aioreq_pri $pri;
630	add $grp aio_copy $src, $dst, sub {	736	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]);	737	$grp->result ($_[0]);
		738
		739	if (!$_[0]) {
		740	aioreq_pri $pri;
		741	add $grp aio_unlink $src;
		742	}
640	}	743	};
		744	} else {
		745	$grp->result ($_[0]);
641	};	746	}
642
643	$grp
644	}	747	};
		748
		749	$grp
645	}	750	}
646		751
647	=item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs)	752	=item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs)
648		753
649	Scans a directory (similar to C<aio_readdir>) but additionally tries to	754	Scans a directory (similar to C<aio_readdir>) but additionally tries to
…		…
669		774
670	Implementation notes.	775	Implementation notes.
671		776
672	The C<aio_readdir> cannot be avoided, but C<stat()>'ing every entry can.	777	The C<aio_readdir> cannot be avoided, but C<stat()>'ing every entry can.
673		778
		779	If readdir returns file type information, then this is used directly to
		780	find directories.
		781
674	After reading the directory, the modification time, size etc. of the	782	Otherwise, after reading the directory, the modification time, size etc.
675	directory before and after the readdir is checked, and if they match (and	783	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	784	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	785	how many entries are directories (if >= 2). Otherwise, no knowledge of the
678	of subdirectories will be assumed.	786	number of subdirectories will be assumed.
679		787
680	Then entries will be sorted into likely directories (everything without	788	Then entries will be sorted into likely directories a non-initial dot
681	a non-initial dot currently) and likely non-directories (everything	789	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,	790	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	791	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	792	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	793	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	794	filesystems might detect the type of the entry without reading the inode
687	data (e.g. ext2fs filetype feature).	795	data (e.g. ext2fs filetype feature), even on systems that cannot return
		796	the filetype information on readdir.
688		797
689	If the known number of directories (link count - 2) has been reached, the	798	If the known number of directories (link count - 2) has been reached, the
690	rest of the entries is assumed to be non-directories.	799	rest of the entries is assumed to be non-directories.
691		800
692	This only works with certainty on POSIX (= UNIX) filesystems, which	801	This only works with certainty on POSIX (= UNIX) filesystems, which
…		…
697	directory counting heuristic.	806	directory counting heuristic.
698		807
699	=cut	808	=cut
700		809
701	sub aio_scandir($$;$) {	810	sub aio_scandir($$;$) {
702	aio_block {
703	my ($path, $maxreq, $cb) = @_;	811	my ($path, $maxreq, $cb) = @_;
704		812
705	my $pri = aioreq_pri;	813	my $pri = aioreq_pri;
706		814
707	my $grp = aio_group $cb;	815	my $grp = aio_group $cb;
708		816
709	$maxreq = 4 if $maxreq <= 0;	817	$maxreq = 4 if $maxreq <= 0;
710		818
711	# stat once	819	# stat once
		820	aioreq_pri $pri;
		821	add $grp aio_stat $path, sub {
		822	return $grp->result () if $_[0];
		823	my $now = time;
		824	my $hash1 = join ":", (stat _)[0,1,3,7,9];
		825
		826	# read the directory entries
712	aioreq_pri $pri;	827	aioreq_pri $pri;
713	add $grp aio_stat $path, sub {	828	add $grp aio_readdirx $path, READDIR_DIRS_FIRST, sub {
		829	my $entries = shift
714	return $grp->result () if $_[0];	830	or return $grp->result ();
715	my $now = time;
716	my $hash1 = join ":", (stat _)[0,1,3,7,9];
717		831
718	# read the directory entries	832	# stat the dir another time
719	aioreq_pri $pri;	833	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 {	834	add $grp aio_stat $path, sub {
727	my $hash2 = join ":", (stat _)[0,1,3,7,9];	835	my $hash2 = join ":", (stat _)[0,1,3,7,9];
728		836
729	my $ndirs;	837	my $ndirs;
730		838
731	# take the slow route if anything looks fishy	839	# take the slow route if anything looks fishy
732	if ($hash1 ne $hash2 or (stat _)[9] == $now) {	840	if ($hash1 ne $hash2 or (stat _)[9] == $now) {
733	$ndirs = -1;	841	$ndirs = -1;
734	} else {	842	} else {
735	# if nlink == 2, we are finished	843	# if nlink == 2, we are finished
736	# on non-posix-fs's, we rely on nlink < 2	844	# for non-posix-fs's, we rely on nlink < 2
737	$ndirs = (stat _)[3] - 2	845	$ndirs = (stat _)[3] - 2
738	or return $grp->result ([], $entries);	846	or return $grp->result ([], $entries);
739	}	847	}
740		848
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);	849	my (@dirs, @nondirs);
749		850
750	my $statgrp = add $grp aio_group sub {	851	my $statgrp = add $grp aio_group sub {
751	$grp->result (\@dirs, \@nondirs);	852	$grp->result (\@dirs, \@nondirs);
752	};	853	};
753		854
754	limit $statgrp $maxreq;	855	limit $statgrp $maxreq;
755	feed $statgrp sub {	856	feed $statgrp sub {
756	return unless @$entries;	857	return unless @$entries;
757	my $entry = pop @$entries;	858	my $entry = shift @$entries;
758		859
759	aioreq_pri $pri;	860	aioreq_pri $pri;
760	add $statgrp aio_stat "$path/$entry/.", sub {	861	add $statgrp aio_stat "$path/$entry/.", sub {
761	if ($_[0] < 0) {	862	if ($_[0] < 0) {
762	push @nondirs, $entry;	863	push @nondirs, $entry;
763	} else {	864	} else {
764	# need to check for real directory	865	# need to check for real directory
765	aioreq_pri $pri;	866	aioreq_pri $pri;
766	add $statgrp aio_lstat "$path/$entry", sub {	867	add $statgrp aio_lstat "$path/$entry", sub {
767	if (-d _) {	868	if (-d _) {
768	push @dirs, $entry;	869	push @dirs, $entry;
769		870
770	unless (--$ndirs) {	871	unless (--$ndirs) {
771	push @nondirs, @$entries;	872	push @nondirs, @$entries;
772	feed $statgrp;	873	feed $statgrp;
773	}
774	} else {
775	push @nondirs, $entry;
776	}	874	}
		875	} else {
		876	push @nondirs, $entry;
777	}	877	}
778	}	878	}
779	};	879	}
780	};	880	};
781	};	881	};
782	};	882	};
783	};	883	};
784
785	$grp
786	}	884	};
		885
		886	$grp
787	}	887	}
788		888
789	=item aio_rmtree $path, $callback->($status)	889	=item aio_rmtree $path, $callback->($status)
790		890
791	Delete a directory tree starting (and including) C<$path>, return the	891	Delete a directory tree starting (and including) C<$path>, return the
…		…
795		895
796	=cut	896	=cut
797		897
798	sub aio_rmtree;	898	sub aio_rmtree;
799	sub aio_rmtree($;$) {	899	sub aio_rmtree($;$) {
800	aio_block {
801	my ($path, $cb) = @_;	900	my ($path, $cb) = @_;
802		901
803	my $pri = aioreq_pri;	902	my $pri = aioreq_pri;
804	my $grp = aio_group $cb;	903	my $grp = aio_group $cb;
805		904
806	aioreq_pri $pri;	905	aioreq_pri $pri;
807	add $grp aio_scandir $path, 0, sub {	906	add $grp aio_scandir $path, 0, sub {
808	my ($dirs, $nondirs) = @_;	907	my ($dirs, $nondirs) = @_;
809		908
810	my $dirgrp = aio_group sub {	909	my $dirgrp = aio_group sub {
811	add $grp aio_rmdir $path, sub {	910	add $grp aio_rmdir $path, sub {
812	$grp->result ($_[0]);	911	$grp->result ($_[0]);
813	};
814	};	912	};
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	};	913	};
821		914
822	$grp	915	(aioreq_pri $pri), add $dirgrp aio_rmtree "$path/$_" for @$dirs;
		916	(aioreq_pri $pri), add $dirgrp aio_unlink "$path/$_" for @$nondirs;
		917
		918	add $grp $dirgrp;
823	}	919	};
		920
		921	$grp
824	}	922	}
		923
		924	=item aio_sync $callback->($status)
		925
		926	Asynchronously call sync and call the callback when finished.
825		927
826	=item aio_fsync $fh, $callback->($status)	928	=item aio_fsync $fh, $callback->($status)
827		929
828	Asynchronously call fsync on the given filehandle and call the callback	930	Asynchronously call fsync on the given filehandle and call the callback
829	with the fsync result code.	931	with the fsync result code.
…		…
833	Asynchronously call fdatasync on the given filehandle and call the	935	Asynchronously call fdatasync on the given filehandle and call the
834	callback with the fdatasync result code.	936	callback with the fdatasync result code.
835		937
836	If this call isn't available because your OS lacks it or it couldn't be	938	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.	939	detected, it will be emulated by calling C<fsync> instead.
		940
		941	=item aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status)
		942
		943	Sync the data portion of the file specified by C<$offset> and C<$length>
		944	to disk (but NOT the metadata), by calling the Linux-specific
		945	sync_file_range call. If sync_file_range is not available or it returns
		946	ENOSYS, then fdatasync or fsync is being substituted.
		947
		948	C<$flags> can be a combination of C<IO::AIO::SYNC_FILE_RANGE_WAIT_BEFORE>,
		949	C<IO::AIO::SYNC_FILE_RANGE_WRITE> and
		950	C<IO::AIO::SYNC_FILE_RANGE_WAIT_AFTER>: refer to the sync_file_range
		951	manpage for details.
		952
		953	=item aio_pathsync $path, $callback->($status)
		954
		955	This request tries to open, fsync and close the given path. This is a
		956	composite request intended to sync directories after directory operations
		957	(E.g. rename). This might not work on all operating systems or have any
		958	specific effect, but usually it makes sure that directory changes get
		959	written to disc. It works for anything that can be opened for read-only,
		960	not just directories.
		961
		962	Future versions of this function might fall back to other methods when
		963	C<fsync> on the directory fails (such as calling C<sync>).
		964
		965	Passes C<0> when everything went ok, and C<-1> on error.
		966
		967	=cut
		968
		969	sub aio_pathsync($;$) {
		970	my ($path, $cb) = @_;
		971
		972	my $pri = aioreq_pri;
		973	my $grp = aio_group $cb;
		974
		975	aioreq_pri $pri;
		976	add $grp aio_open $path, O_RDONLY, 0, sub {
		977	my ($fh) = @_;
		978	if ($fh) {
		979	aioreq_pri $pri;
		980	add $grp aio_fsync $fh, sub {
		981	$grp->result ($_[0]);
		982
		983	aioreq_pri $pri;
		984	add $grp aio_close $fh;
		985	};
		986	} else {
		987	$grp->result (-1);
		988	}
		989	};
		990
		991	$grp
		992	}
838		993
839	=item aio_group $callback->(...)	994	=item aio_group $callback->(...)
840		995
841	This is a very special aio request: Instead of doing something, it is a	996	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	997	container for other aio requests, which is useful if you want to bundle
…		…
892	=item cancel $req	1047	=item cancel $req
893		1048
894	Cancels the request, if possible. Has the effect of skipping execution	1049	Cancels the request, if possible. Has the effect of skipping execution
895	when entering the B<execute> state and skipping calling the callback when	1050	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	1051	entering the the B<result> state, but will leave the request otherwise
897	untouched. That means that requests that currently execute will not be	1052	untouched (with the exception of readdir). That means that requests that
898	stopped and resources held by the request will not be freed prematurely.	1053	currently execute will not be stopped and resources held by the request
		1054	will not be freed prematurely.
899		1055
900	=item cb $req $callback->(...)	1056	=item cb $req $callback->(...)
901		1057
902	Replace (or simply set) the callback registered to the request.	1058	Replace (or simply set) the callback registered to the request.
903		1059
…		…
954	Their lifetime, simplified, looks like this: when they are empty, they	1110	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	1111	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	1112	C<done> state, they will also finish. Otherwise they will continue to
957	exist.	1113	exist.
958		1114
959	That means after creating a group you have some time to add requests. And	1115	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	1116	(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	1117	the C<poll_cb>). And in the callbacks of those requests, you can add
962	itself finish.	1118	further requests to the group. And only when all those requests have
		1119	finished will the the group itself finish.
963		1120
964	=over 4	1121	=over 4
965		1122
966	=item add $grp ...	1123	=item add $grp ...
967		1124
…		…
979	itself. Useful when you queued a lot of events but got a result early.	1136	itself. Useful when you queued a lot of events but got a result early.
980		1137
981	=item $grp->result (...)	1138	=item $grp->result (...)
982		1139
983	Set the result value(s) that will be passed to the group callback when all	1140	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	1141	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,	1142	of errno (just like calling C<errno> without an error number). By default,
986	no argument will be passed and errno is zero.	1143	no argument will be passed and errno is zero.
987		1144
988	=item $grp->errno ([$errno])	1145	=item $grp->errno ([$errno])
989		1146
…		…
1000	=item feed $grp $callback->($grp)	1157	=item feed $grp $callback->($grp)
1001		1158
1002	Sets a feeder/generator on this group: every group can have an attached	1159	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,	1160	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,	1161	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	1162	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>	1163	C<aio_scandir> might generate hundreds of thousands C<aio_stat> requests,
1007	requests, delaying any later requests for a long time.	1164	delaying any later requests for a long time.
1008		1165
1009	To avoid this, and allow incremental generation of requests, you can	1166	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	1167	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>,	1168	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	1169	below) requests active in the group itself and is expected to queue more
…		…
1016	not impose any limits).	1173	not impose any limits).
1017		1174
1018	If the feed does not queue more requests when called, it will be	1175	If the feed does not queue more requests when called, it will be
1019	automatically removed from the group.	1176	automatically removed from the group.
1020		1177
1021	If the feed limit is C<0>, it will be set to C<2> automatically.	1178	If the feed limit is C<0> when this method is called, it will be set to
		1179	C<2> automatically.
1022		1180
1023	Example:	1181	Example:
1024		1182
1025	# stat all files in @files, but only ever use four aio requests concurrently:	1183	# stat all files in @files, but only ever use four aio requests concurrently:
1026		1184
…		…
1038	Sets the feeder limit for the group: The feeder will be called whenever	1196	Sets the feeder limit for the group: The feeder will be called whenever
1039	the group contains less than this many requests.	1197	the group contains less than this many requests.
1040		1198
1041	Setting the limit to C<0> will pause the feeding process.	1199	Setting the limit to C<0> will pause the feeding process.
1042		1200
		1201	The default value for the limit is C<0>, but note that setting a feeder
		1202	automatically bumps it up to C<2>.
		1203
1043	=back	1204	=back
1044		1205
1045	=head2 SUPPORT FUNCTIONS	1206	=head2 SUPPORT FUNCTIONS
1046		1207
1047	=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION	1208	=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION
…		…
1049	=over 4	1210	=over 4
1050		1211
1051	=item $fileno = IO::AIO::poll_fileno	1212	=item $fileno = IO::AIO::poll_fileno
1052		1213
1053	Return the I<request result pipe file descriptor>. This filehandle must be	1214	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	1215	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	1216	select and so on, see below or the SYNOPSIS). If the pipe becomes readable
1056	to call C<poll_cb> to check the results.	1217	you have to call C<poll_cb> to check the results.
1057		1218
1058	See C<poll_cb> for an example.	1219	See C<poll_cb> for an example.
1059		1220
1060	=item IO::AIO::poll_cb	1221	=item IO::AIO::poll_cb
1061		1222
1062	Process some outstanding events on the result pipe. You have to call this	1223	Process some outstanding events on the result pipe. You have to call this
1063	regularly. Returns the number of events processed. Returns immediately	1224	regularly. Returns C<0> if all events could be processed, or C<-1> if it
		1225	returned earlier for whatever reason. Returns immediately when no events
1064	when no events are outstanding. The amount of events processed depends on	1226	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>.	1227	C<IO::AIO::max_poll_req> and C<IO::AIO::max_poll_time>.
1066		1228
1067	If not all requests were processed for whatever reason, the filehandle	1229	If not all requests were processed for whatever reason, the filehandle
1068	will still be ready when C<poll_cb> returns.	1230	will still be ready when C<poll_cb> returns, so normally you don't have to
		1231	do anything special to have it called later.
1069		1232
1070	Example: Install an Event watcher that automatically calls	1233	Example: Install an Event watcher that automatically calls
1071	IO::AIO::poll_cb with high priority:	1234	IO::AIO::poll_cb with high priority (more examples can be found in the
		1235	SYNOPSIS section, at the top of this document):
1072		1236
1073	Event->io (fd => IO::AIO::poll_fileno,	1237	Event->io (fd => IO::AIO::poll_fileno,
1074	poll => 'r', async => 1,	1238	poll => 'r', async => 1,
1075	cb => \&IO::AIO::poll_cb);	1239	cb => \&IO::AIO::poll_cb);
1076		1240
…		…
1187		1351
1188	The default is probably ok in most situations, especially if thread	1352	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	1353	creation is fast. If thread creation is very slow on your system you might
1190	want to use larger values.	1354	want to use larger values.
1191		1355
1192	=item $oldmaxreqs = IO::AIO::max_outstanding $maxreqs	1356	=item IO::AIO::max_outstanding $maxreqs
1193		1357
1194	This is a very bad function to use in interactive programs because it	1358	This is a very bad function to use in interactive programs because it
1195	blocks, and a bad way to reduce concurrency because it is inexact: Better	1359	blocks, and a bad way to reduce concurrency because it is inexact: Better
1196	use an C<aio_group> together with a feed callback.	1360	use an C<aio_group> together with a feed callback.
1197		1361
1198	Sets the maximum number of outstanding requests to C<$nreqs>. If you	1362	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	1363	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>)	1364	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.	1365	function will block until the limit is no longer exceeded.
1202		1366
1203	The default value is very large, so there is no practical limit on the	1367	The default value is very large, so there is no practical limit on the
1204	number of outstanding requests.	1368	number of outstanding requests.
1205		1369
1206	You can still queue as many requests as you want. Therefore,	1370	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	1371	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).	1372	as a stop gap to shield against fatal memory overflow (with large values).
1209		1373
1210	=back	1374	=back
1211		1375
1212	=head3 STATISTICAL INFORMATION	1376	=head3 STATISTICAL INFORMATION
…		…
1233	Returns the number of requests currently in the pending state (executed,	1397	Returns the number of requests currently in the pending state (executed,
1234	but not yet processed by poll_cb).	1398	but not yet processed by poll_cb).
1235		1399
1236	=back	1400	=back
1237		1401
		1402	=head3 MISCELLANEOUS FUNCTIONS
		1403
		1404	IO::AIO implements some functions that might be useful, but are not
		1405	asynchronous.
		1406
		1407	=over 4
		1408
		1409	=item IO::AIO::sendfile $ofh, $ifh, $offset, $count
		1410
		1411	Calls the C<eio_sendfile_sync> function, which is like C<aio_sendfile>,
		1412	but is blocking (this makes most sense if you know the input data is
		1413	likely cached already and the output filehandle is set to non-blocking
		1414	operations).
		1415
		1416	Returns the number of bytes copied, or C<-1> on error.
		1417
		1418	=item IO::AIO::fadvise $fh, $offset, $len, $advice
		1419
		1420	Simply calls the C<posix_fadvise> function (see it's
		1421	manpage for details). The following advice constants are
		1422	avaiable: C<IO::AIO::FADV_NORMAL>, C<IO::AIO::FADV_SEQUENTIAL>,
		1423	C<IO::AIO::FADV_RANDOM>, C<IO::AIO::FADV_NOREUSE>,
		1424	C<IO::AIO::FADV_WILLNEED>, C<IO::AIO::FADV_DONTNEED>.
		1425
		1426	On systems that do not implement C<posix_fadvise>, this function returns
		1427	ENOSYS, otherwise the return value of C<posix_fadvise>.
		1428
		1429	=back
		1430
1238	=cut	1431	=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		1432
1256	min_parallel 8;	1433	min_parallel 8;
1257		1434
1258	END { flush }	1435	END { flush }
1259		1436
…		…
1283	bytes of memory. In addition, stat requests need a stat buffer (possibly	1460	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	1461	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	1462	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.	1463	will consume memory till the request has entered the done state.
1287		1464
1288	This is now awfully much, so queuing lots of requests is not usually a	1465	This is not awfully much, so queuing lots of requests is not usually a
1289	problem.	1466	problem.
1290		1467
1291	Per-thread usage:	1468	Per-thread usage:
1292		1469
1293	In the execution phase, some aio requests require more memory for	1470	In the execution phase, some aio requests require more memory for
…		…
1298		1475
1299	Known bugs will be fixed in the next release.	1476	Known bugs will be fixed in the next release.
1300		1477
1301	=head1 SEE ALSO	1478	=head1 SEE ALSO
1302		1479
1303	L<Coro::AIO>.	1480	L<AnyEvent::AIO> for easy integration into event loops, L<Coro::AIO> for a
		1481	more natural syntax.
1304		1482
1305	=head1 AUTHOR	1483	=head1 AUTHOR
1306		1484
1307	Marc Lehmann <schmorp@schmorp.de>	1485	Marc Lehmann <schmorp@schmorp.de>
1308	http://home.schmorp.de/	1486	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 1.164 by root, Tue Aug 18 03:26:02 2009 UTC

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Revision 1.107 by root, Fri Jun 1 05:52:59 2007 UTC vs.
Revision 1.164 by root, Tue Aug 18 03:26:02 2009 UTC