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

Comparing IO-AIO/AIO.pm (file contents):
Revision 1.109 by root, Sun Jun 3 09:44:17 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
…		…
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	70	While most of this works on all types of file descriptors (for
68	example sockets), using these functions on file descriptors that	71	example sockets), using these functions on file descriptors that
69	support nonblocking operation (again, sockets, pipes etc.) is very	72	support nonblocking operation (again, sockets, pipes etc.) is
70	inefficient. Use an event loop for that (such as the L<Event\|Event>	73	very inefficient. Use an event loop for that (such as the L<EV>
71	module): IO::AIO will naturally fit into such an event loop itself.	74	module): IO::AIO will naturally fit into such an event loop itself.
72		75
73	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
74	requests and signal their completion. You don't need thread support	77	requests and signal their completion. You don't need thread support
75	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
…		…
85	yourself, always call C<poll_cb> from within the same thread, or never	88	yourself, always call C<poll_cb> from within the same thread, or never
86	call C<poll_cb> (or other C<aio_> functions) recursively.	89	call C<poll_cb> (or other C<aio_> functions) recursively.
87		90
88	=head2 EXAMPLE	91	=head2 EXAMPLE
89		92
90	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
91	F</etc/passwd> asynchronously:	94	F</etc/passwd> asynchronously:
92		95
93	use Fcntl;	96	use Fcntl;
94	use Event;	97	use EV;
95	use IO::AIO;	98	use IO::AIO;
96		99
97	# register the IO::AIO callback with Event	100	# register the IO::AIO callback with EV
98	Event->io (fd => IO::AIO::poll_fileno,	101	my $aio_w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb;
99	poll => 'r',
100	cb => \&IO::AIO::poll_cb);
101		102
102	# queue the request to open /etc/passwd	103	# queue the request to open /etc/passwd
103	aio_open "/etc/passwd", O_RDONLY, 0, sub {	104	aio_open "/etc/passwd", O_RDONLY, 0, sub {
104	my $fh = shift	105	my $fh = shift
105	or die "error while opening: $!";	106	or die "error while opening: $!";
…		…
117		118
118	# file contents now in $contents	119	# file contents now in $contents
119	print $contents;	120	print $contents;
120		121
121	# exit event loop and program	122	# exit event loop and program
122	Event::unloop;	123	EV::unloop;
123	};	124	};
124	};	125	};
125		126
126	# possibly queue up other requests, or open GUI windows,	127	# possibly queue up other requests, or open GUI windows,
127	# check for sockets etc. etc.	128	# check for sockets etc. etc.
128		129
129	# process events as long as there are some:	130	# process events as long as there are some:
130	Event::loop;	131	EV::loop;
131		132
132	=head1 REQUEST ANATOMY AND LIFETIME	133	=head1 REQUEST ANATOMY AND LIFETIME
133		134
134	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
135	directly visible to Perl.	136	directly visible to Perl.
…		…
183		184
184	=cut	185	=cut
185		186
186	package IO::AIO;	187	package IO::AIO;
187		188
188	no warnings;	189	use Carp ();
189	use strict 'vars';	190
		191	use common::sense;
190		192
191	use base 'Exporter';	193	use base 'Exporter';
192		194
193	BEGIN {	195	BEGIN {
194	our $VERSION = '2.4';	196	our $VERSION = '3.4';
195		197
196	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
197	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
198	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
199	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
200	aio_chown aio_chmod aio_utime);	204	aio_chmod aio_utime aio_truncate
		205	aio_msync aio_mtouch);
		206
201	our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice aio_block));	207	our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice));
202	our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush	208	our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush
203	min_parallel max_parallel max_idle	209	min_parallel max_parallel max_idle
204	nreqs nready npending nthreads	210	nreqs nready npending nthreads
205	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
206		215
207	@IO::AIO::GRP::ISA = 'IO::AIO::REQ';	216	@IO::AIO::GRP::ISA = 'IO::AIO::REQ';
208		217
209	require XSLoader;	218	require XSLoader;
210	XSLoader::load ("IO::AIO", $VERSION);	219	XSLoader::load ("IO::AIO", $VERSION);
…		…
217	All the C<aio_*> calls are more or less thin wrappers around the syscall	226	All the C<aio_*> calls are more or less thin wrappers around the syscall
218	with the same name (sans C<aio_>). The arguments are similar or identical,	227	with the same name (sans C<aio_>). The arguments are similar or identical,
219	and they all accept an additional (and optional) C<$callback> argument	228	and they all accept an additional (and optional) C<$callback> argument
220	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
221	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
222	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
223	syscall has been executed asynchronously.	232	syscall has been executed asynchronously.
224		233
225	All functions expecting a filehandle keep a copy of the filehandle	234	All functions expecting a filehandle keep a copy of the filehandle
226	internally until the request has finished.	235	internally until the request has finished.
227		236
…		…
241	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
242	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)
243	use something else to ensure your scalar has the correct contents.	252	use something else to ensure your scalar has the correct contents.
244		253
245	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
246	handles correctly wether it is set or not.	255	handles correctly whether it is set or not.
247		256
248	=over 4	257	=over 4
249		258
250	=item $prev_pri = aioreq_pri [$pri]	259	=item $prev_pri = aioreq_pri [$pri]
251		260
…		…
311		320
312		321
313	=item aio_close $fh, $callback->($status)	322	=item aio_close $fh, $callback->($status)
314		323
315	Asynchronously close a file and call the callback with the result	324	Asynchronously close a file and call the callback with the result
316	code. I<WARNING:> although accepted, you should not pass in a perl	325	code.
317	filehandle here, as perl will likely close the file descriptor another
318	time when the filehandle is destroyed. Normally, you can safely call perls
319	C<close> or just let filehandles go out of scope.
320		326
321	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
322	therefore best to avoid this function.	328	closing the file descriptor associated with the filehandle itself.
323		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
324		338
325	=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)	339	=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
326		340
327	=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)	341	=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
328		342
329	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<$fh> and
330	into the scalar given by C<$data> and offset C<$dataoffset> and calls the	344	C<$offset> into the scalar given by C<$data> and offset C<$dataoffset>
331	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
332	like the syscall).	346	error, just like the syscall).
333		347
		348	C<aio_read> will, like C<sysread>, shrink or grow the C<$data> scalar to
		349	offset plus the actual number of bytes read.
		350
334	If C<$offset> is undefined, then the current file offset will be used (and	351	If C<$offset> is undefined, then the current file descriptor offset will
335	updated), otherwise the file offset will not be changed by these calls.	352	be used (and updated), otherwise the file descriptor offset will not be
		353	changed by these calls.
336		354
337	If C<$length> is undefined in C<aio_write>, use the remaining length of C<$data>.	355	If C<$length> is undefined in C<aio_write>, use the remaining length of
		356	C<$data>.
338		357
339	If C<$dataoffset> is less than zero, it will be counted from the end of	358	If C<$dataoffset> is less than zero, it will be counted from the end of
340	C<$data>.	359	C<$data>.
341		360
342	The C<$data> scalar I<MUST NOT> be modified in any way while the request	361	The C<$data> scalar I<MUST NOT> be modified in any way while the request
…		…
362		381
363	This call tries to make use of a native C<sendfile> syscall to provide	382	This call tries to make use of a native C<sendfile> syscall to provide
364	zero-copy operation. For this to work, C<$out_fh> should refer to a	383	zero-copy operation. For this to work, C<$out_fh> should refer to a
365	socket, and C<$in_fh> should refer to mmap'able file.	384	socket, and C<$in_fh> should refer to mmap'able file.
366		385
367	If the native sendfile call fails or is not implemented, it will be	386	If a native sendfile cannot be found or it fails with C<ENOSYS>,
		387	C<ENOTSUP>, C<EOPNOTSUPP>, C<EAFNOSUPPORT>, C<EPROTOTYPE> or C<ENOTSOCK>,
368	emulated, so you can call C<aio_sendfile> on any type of filehandle	388	it will be emulated, so you can call C<aio_sendfile> on any type of
369	regardless of the limitations of the operating system.	389	filehandle regardless of the limitations of the operating system.
370		390
371	Please note, however, that C<aio_sendfile> can read more bytes from	391	Please note, however, that C<aio_sendfile> can read more bytes from
372	C<$in_fh> than are written, and there is no way to find out how many	392	C<$in_fh> than are written, and there is no way to find out how many
373	bytes have been read from C<aio_sendfile> alone, as C<aio_sendfile> only	393	bytes have been read from C<aio_sendfile> alone, as C<aio_sendfile> only
374	provides the number of bytes written to C<$out_fh>. Only if the result	394	provides the number of bytes written to C<$out_fh>. Only if the result
…		…
443	aio_chown "path", 0, -1;	463	aio_chown "path", 0, -1;
444	# same as above:	464	# same as above:
445	aio_chown "path", 0, undef;	465	aio_chown "path", 0, undef;
446		466
447		467
		468	=item aio_truncate $fh_or_path, $offset, $callback->($status)
		469
		470	Works like truncate(2) or ftruncate(2).
		471
		472
448	=item aio_chmod $fh_or_path, $mode, $callback->($status)	473	=item aio_chmod $fh_or_path, $mode, $callback->($status)
449		474
450	Works like perl's C<chmod> function.	475	Works like perl's C<chmod> function.
451		476
452		477
…		…
509		534
510	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
511	directory (i.e. opendir + readdir + closedir). The entries will not be	536	directory (i.e. opendir + readdir + closedir). The entries will not be
512	sorted, and will B<NOT> include the C<.> and C<..> entries.	537	sorted, and will B<NOT> include the C<.> and C<..> entries.
513		538
514	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
515	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
516		607
517		608
518	=item aio_load $path, $data, $callback->($status)	609	=item aio_load $path, $data, $callback->($status)
519		610
520	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
521	memory. Status is the same as with aio_read.	612	memory. Status is the same as with aio_read.
522		613
523	=cut	614	=cut
524		615
525	sub aio_load($$;$) {	616	sub aio_load($$;$) {
526	aio_block {
527	my ($path, undef, $cb) = @_;	617	my ($path, undef, $cb) = @_;
528	my $data = \$_[1];	618	my $data = \$_[1];
529		619
530	my $pri = aioreq_pri;	620	my $pri = aioreq_pri;
531	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);
532		627
533	aioreq_pri $pri;	628	aioreq_pri $pri;
534	add $grp aio_open $path, O_RDONLY, 0, sub {
535	my $fh = shift
536	or return $grp->result (-1);
537
538	aioreq_pri $pri;
539	add $grp aio_read $fh, 0, (-s $fh), $$data, 0, sub {	629	add $grp aio_read $fh, 0, (-s $fh), $$data, 0, sub {
540	$grp->result ($_[0]);	630	$grp->result ($_[0]);
541	};
542	};	631	};
543
544	$grp
545	}	632	};
		633
		634	$grp
546	}	635	}
547		636
548	=item aio_copy $srcpath, $dstpath, $callback->($status)	637	=item aio_copy $srcpath, $dstpath, $callback->($status)
549		638
550	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
551	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
552	the C<0> (error) or C<-1> ok.	641	a status of C<0> (ok) or C<-1> (error, see C<$!>).
553		642
554	This is a composite request that it creates the destination file with	643	This is a composite request that creates the destination file with
555	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
556	C<aio_sendfile>, followed by restoring atime, mtime, access mode and	645	C<aio_sendfile>, followed by restoring atime, mtime, access mode and
557	uid/gid, in that order.	646	uid/gid, in that order.
558		647
559	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
…		…
561	errors are being ignored.	650	errors are being ignored.
562		651
563	=cut	652	=cut
564		653
565	sub aio_copy($$;$) {	654	sub aio_copy($$;$) {
566	aio_block {
567	my ($src, $dst, $cb) = @_;	655	my ($src, $dst, $cb) = @_;
568		656
569	my $pri = aioreq_pri;	657	my $pri = aioreq_pri;
570	my $grp = aio_group $cb;	658	my $grp = aio_group $cb;
571		659
572	aioreq_pri $pri;	660	aioreq_pri $pri;
573	add $grp aio_open $src, O_RDONLY, 0, sub {	661	add $grp aio_open $src, O_RDONLY, 0, sub {
574	if (my $src_fh = $_[0]) {	662	if (my $src_fh = $_[0]) {
575	my @stat = stat $src_fh;	663	my @stat = stat $src_fh; # hmm, might block over nfs?
576		664
577	aioreq_pri $pri;	665	aioreq_pri $pri;
578	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 {
579	if (my $dst_fh = $_[0]) {	667	if (my $dst_fh = $_[0]) {
580	aioreq_pri $pri;	668	aioreq_pri $pri;
581	add $grp aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub {	669	add $grp aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub {
582	if ($_[0] == $stat[7]) {	670	if ($_[0] == $stat[7]) {
583	$grp->result (0);	671	$grp->result (0);
584	close $src_fh;	672	close $src_fh;
585		673
586	# those should not normally block. should. should.
587	utime $stat[8], $stat[9], $dst;
588	chmod $stat[2] & 07777, $dst_fh;
589	chown $stat[4], $stat[5], $dst_fh;
590	close $dst_fh;
591	} else {	674	my $ch = sub {
592	$grp->result (-1);
593	close $src_fh;
594	close $dst_fh;
595
596	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;
597	add $grp aio_unlink $dst;	680	add $grp aio_close $dst_fh;
		681	}
		682	};
598	}	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;
599	};	701	}
600	} else {
601	$grp->result (-1);
602	}	702	};
		703	} else {
		704	$grp->result (-1);
603	},	705	}
604
605	} else {
606	$grp->result (-1);
607	}	706	},
		707
		708	} else {
		709	$grp->result (-1);
608	};	710	}
609
610	$grp
611	}	711	};
		712
		713	$grp
612	}	714	}
613		715
614	=item aio_move $srcpath, $dstpath, $callback->($status)	716	=item aio_move $srcpath, $dstpath, $callback->($status)
615		717
616	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
617	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
618	the C<0> (error) or C<-1> ok.	720	a status of C<0> (ok) or C<-1> (error, see C<$!>).
619		721
620	This is a composite request that tries to rename(2) the file first. If	722	This is a composite request that tries to rename(2) the file first; if
621	rename files with C<EXDEV>, it copies the file with C<aio_copy> and, if	723	rename fails with C<EXDEV>, it copies the file with C<aio_copy> and, if
622	that is successful, unlinking the C<$srcpath>.	724	that is successful, unlinks the C<$srcpath>.
623		725
624	=cut	726	=cut
625		727
626	sub aio_move($$;$) {	728	sub aio_move($$;$) {
627	aio_block {
628	my ($src, $dst, $cb) = @_;	729	my ($src, $dst, $cb) = @_;
629		730
630	my $pri = aioreq_pri;	731	my $pri = aioreq_pri;
631	my $grp = aio_group $cb;	732	my $grp = aio_group $cb;
632		733
633	aioreq_pri $pri;	734	aioreq_pri $pri;
634	add $grp aio_rename $src, $dst, sub {	735	add $grp aio_rename $src, $dst, sub {
635	if ($_[0] && $! == EXDEV) {	736	if ($_[0] && $! == EXDEV) {
636	aioreq_pri $pri;	737	aioreq_pri $pri;
637	add $grp aio_copy $src, $dst, sub {	738	add $grp aio_copy $src, $dst, sub {
638	$grp->result ($_[0]);
639
640	if (!$_[0]) {
641	aioreq_pri $pri;
642	add $grp aio_unlink $src;
643	}
644	};
645	} else {
646	$grp->result ($_[0]);	739	$grp->result ($_[0]);
		740
		741	if (!$_[0]) {
		742	aioreq_pri $pri;
		743	add $grp aio_unlink $src;
		744	}
647	}	745	};
		746	} else {
		747	$grp->result ($_[0]);
648	};	748	}
649
650	$grp
651	}	749	};
		750
		751	$grp
652	}	752	}
653		753
654	=item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs)	754	=item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs)
655		755
656	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
…		…
676		776
677	Implementation notes.	777	Implementation notes.
678		778
679	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.
680		780
		781	If readdir returns file type information, then this is used directly to
		782	find directories.
		783
681	After reading the directory, the modification time, size etc. of the	784	Otherwise, after reading the directory, the modification time, size etc.
682	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
683	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
684	entries are directories (if >= 2). Otherwise, no knowledge of the number	787	how many entries are directories (if >= 2). Otherwise, no knowledge of the
685	of subdirectories will be assumed.	788	number of subdirectories will be assumed.
686		789
687	Then entries will be sorted into likely directories (everything without	790	Then entries will be sorted into likely directories a non-initial dot
688	a non-initial dot currently) and likely non-directories (everything	791	currently) and likely non-directories (see C<aio_readdirx>). Then every
689	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,
690	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
691	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
692	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
693	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
694	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.
695		799
696	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
697	rest of the entries is assumed to be non-directories.	801	rest of the entries is assumed to be non-directories.
698		802
699	This only works with certainty on POSIX (= UNIX) filesystems, which	803	This only works with certainty on POSIX (= UNIX) filesystems, which
…		…
704	directory counting heuristic.	808	directory counting heuristic.
705		809
706	=cut	810	=cut
707		811
708	sub aio_scandir($$;$) {	812	sub aio_scandir($$;$) {
709	aio_block {
710	my ($path, $maxreq, $cb) = @_;	813	my ($path, $maxreq, $cb) = @_;
711		814
712	my $pri = aioreq_pri;	815	my $pri = aioreq_pri;
713		816
714	my $grp = aio_group $cb;	817	my $grp = aio_group $cb;
715		818
716	$maxreq = 4 if $maxreq <= 0;	819	$maxreq = 4 if $maxreq <= 0;
717		820
718	# 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
719	aioreq_pri $pri;	829	aioreq_pri $pri;
720	add $grp aio_stat $path, sub {	830	add $grp aio_readdirx $path, READDIR_DIRS_FIRST, sub {
		831	my $entries = shift
721	return $grp->result () if $_[0];	832	or return $grp->result ();
722	my $now = time;
723	my $hash1 = join ":", (stat _)[0,1,3,7,9];
724		833
725	# read the directory entries	834	# stat the dir another time
726	aioreq_pri $pri;	835	aioreq_pri $pri;
727	add $grp aio_readdir $path, sub {
728	my $entries = shift
729	or return $grp->result ();
730
731	# stat the dir another time
732	aioreq_pri $pri;
733	add $grp aio_stat $path, sub {	836	add $grp aio_stat $path, sub {
734	my $hash2 = join ":", (stat _)[0,1,3,7,9];	837	my $hash2 = join ":", (stat _)[0,1,3,7,9];
735		838
736	my $ndirs;	839	my $ndirs;
737		840
738	# take the slow route if anything looks fishy	841	# take the slow route if anything looks fishy
739	if ($hash1 ne $hash2 or (stat _)[9] == $now) {	842	if ($hash1 ne $hash2 or (stat _)[9] == $now) {
740	$ndirs = -1;	843	$ndirs = -1;
741	} else {	844	} else {
742	# if nlink == 2, we are finished	845	# if nlink == 2, we are finished
743	# on non-posix-fs's, we rely on nlink < 2	846	# for non-posix-fs's, we rely on nlink < 2
744	$ndirs = (stat _)[3] - 2	847	$ndirs = (stat _)[3] - 2
745	or return $grp->result ([], $entries);	848	or return $grp->result ([], $entries);
746	}	849	}
747		850
748	# sort into likely dirs and likely nondirs
749	# dirs == files without ".", short entries first
750	$entries = [map $_->[0],
751	sort { $b->[1] cmp $a->[1] }
752	map [$_, sprintf "%s%04d", (/.\./ ? "1" : "0"), length],
753	@$entries];
754
755	my (@dirs, @nondirs);	851	my (@dirs, @nondirs);
756		852
757	my $statgrp = add $grp aio_group sub {	853	my $statgrp = add $grp aio_group sub {
758	$grp->result (\@dirs, \@nondirs);	854	$grp->result (\@dirs, \@nondirs);
759	};	855	};
760		856
761	limit $statgrp $maxreq;	857	limit $statgrp $maxreq;
762	feed $statgrp sub {	858	feed $statgrp sub {
763	return unless @$entries;	859	return unless @$entries;
764	my $entry = pop @$entries;	860	my $entry = shift @$entries;
765		861
766	aioreq_pri $pri;	862	aioreq_pri $pri;
767	add $statgrp aio_stat "$path/$entry/.", sub {	863	add $statgrp aio_stat "$path/$entry/.", sub {
768	if ($_[0] < 0) {	864	if ($_[0] < 0) {
769	push @nondirs, $entry;	865	push @nondirs, $entry;
770	} else {	866	} else {
771	# need to check for real directory	867	# need to check for real directory
772	aioreq_pri $pri;	868	aioreq_pri $pri;
773	add $statgrp aio_lstat "$path/$entry", sub {	869	add $statgrp aio_lstat "$path/$entry", sub {
774	if (-d _) {	870	if (-d _) {
775	push @dirs, $entry;	871	push @dirs, $entry;
776		872
777	unless (--$ndirs) {	873	unless (--$ndirs) {
778	push @nondirs, @$entries;	874	push @nondirs, @$entries;
779	feed $statgrp;	875	feed $statgrp;
780	}
781	} else {
782	push @nondirs, $entry;
783	}	876	}
		877	} else {
		878	push @nondirs, $entry;
784	}	879	}
785	}	880	}
786	};	881	}
787	};	882	};
788	};	883	};
789	};	884	};
790	};	885	};
791
792	$grp
793	}	886	};
		887
		888	$grp
794	}	889	}
795		890
796	=item aio_rmtree $path, $callback->($status)	891	=item aio_rmtree $path, $callback->($status)
797		892
798	Delete a directory tree starting (and including) C<$path>, return the	893	Delete a directory tree starting (and including) C<$path>, return the
…		…
802		897
803	=cut	898	=cut
804		899
805	sub aio_rmtree;	900	sub aio_rmtree;
806	sub aio_rmtree($;$) {	901	sub aio_rmtree($;$) {
807	aio_block {
808	my ($path, $cb) = @_;	902	my ($path, $cb) = @_;
809		903
810	my $pri = aioreq_pri;	904	my $pri = aioreq_pri;
811	my $grp = aio_group $cb;	905	my $grp = aio_group $cb;
812		906
813	aioreq_pri $pri;	907	aioreq_pri $pri;
814	add $grp aio_scandir $path, 0, sub {	908	add $grp aio_scandir $path, 0, sub {
815	my ($dirs, $nondirs) = @_;	909	my ($dirs, $nondirs) = @_;
816		910
817	my $dirgrp = aio_group sub {	911	my $dirgrp = aio_group sub {
818	add $grp aio_rmdir $path, sub {	912	add $grp aio_rmdir $path, sub {
819	$grp->result ($_[0]);	913	$grp->result ($_[0]);
820	};
821	};	914	};
822
823	(aioreq_pri $pri), add $dirgrp aio_rmtree "$path/$_" for @$dirs;
824	(aioreq_pri $pri), add $dirgrp aio_unlink "$path/$_" for @$nondirs;
825
826	add $grp $dirgrp;
827	};	915	};
828		916
829	$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;
830	}	921	};
		922
		923	$grp
831	}	924	}
		925
		926	=item aio_sync $callback->($status)
		927
		928	Asynchronously call sync and call the callback when finished.
832		929
833	=item aio_fsync $fh, $callback->($status)	930	=item aio_fsync $fh, $callback->($status)
834		931
835	Asynchronously call fsync on the given filehandle and call the callback	932	Asynchronously call fsync on the given filehandle and call the callback
836	with the fsync result code.	933	with the fsync result code.
…		…
840	Asynchronously call fdatasync on the given filehandle and call the	937	Asynchronously call fdatasync on the given filehandle and call the
841	callback with the fdatasync result code.	938	callback with the fdatasync result code.
842		939
843	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
844	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).
845		1021
846	=item aio_group $callback->(...)	1022	=item aio_group $callback->(...)
847		1023
848	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
849	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
…		…
899	=item cancel $req	1075	=item cancel $req
900		1076
901	Cancels the request, if possible. Has the effect of skipping execution	1077	Cancels the request, if possible. Has the effect of skipping execution
902	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
903	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
904	untouched. That means that requests that currently execute will not be	1080	untouched (with the exception of readdir). That means that requests that
905	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.
906		1083
907	=item cb $req $callback->(...)	1084	=item cb $req $callback->(...)
908		1085
909	Replace (or simply set) the callback registered to the request.	1086	Replace (or simply set) the callback registered to the request.
910		1087
…		…
961	Their lifetime, simplified, looks like this: when they are empty, they	1138	Their lifetime, simplified, looks like this: when they are empty, they
962	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
963	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
964	exist.	1141	exist.
965		1142
966	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
967	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
968	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
969	itself finish.	1146	further requests to the group. And only when all those requests have
		1147	finished will the the group itself finish.
970		1148
971	=over 4	1149	=over 4
972		1150
973	=item add $grp ...	1151	=item add $grp ...
974		1152
…		…
983	=item $grp->cancel_subs	1161	=item $grp->cancel_subs
984		1162
985	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
986	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.
987		1165
		1166	The group request will finish normally (you cannot add requests to the
		1167	group).
		1168
988	=item $grp->result (...)	1169	=item $grp->result (...)
989		1170
990	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
991	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
992	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,
993	no argument will be passed and errno is zero.	1174	no argument will be passed and errno is zero.
994		1175
995	=item $grp->errno ([$errno])	1176	=item $grp->errno ([$errno])
996		1177
…		…
1007	=item feed $grp $callback->($grp)	1188	=item feed $grp $callback->($grp)
1008		1189
1009	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
1010	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,
1011	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,
1012	this might starve other requests for a potentially long time. For	1193	this might starve other requests for a potentially long time. For example,
1013	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,
1014	requests, delaying any later requests for a long time.	1195	delaying any later requests for a long time.
1015		1196
1016	To avoid this, and allow incremental generation of requests, you can	1197	To avoid this, and allow incremental generation of requests, you can
1017	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
1018	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>,
1019	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
…		…
1023	not impose any limits).	1204	not impose any limits).
1024		1205
1025	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
1026	automatically removed from the group.	1207	automatically removed from the group.
1027		1208
1028	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.
1029		1211
1030	Example:	1212	Example:
1031		1213
1032	# 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:
1033		1215
…		…
1045	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
1046	the group contains less than this many requests.	1228	the group contains less than this many requests.
1047		1229
1048	Setting the limit to C<0> will pause the feeding process.	1230	Setting the limit to C<0> will pause the feeding process.
1049		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
1050	=back	1235	=back
1051		1236
1052	=head2 SUPPORT FUNCTIONS	1237	=head2 SUPPORT FUNCTIONS
1053		1238
1054	=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION	1239	=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION
…		…
1056	=over 4	1241	=over 4
1057		1242
1058	=item $fileno = IO::AIO::poll_fileno	1243	=item $fileno = IO::AIO::poll_fileno
1059		1244
1060	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
1061	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,
1062	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
1063	to call C<poll_cb> to check the results.	1248	you have to call C<poll_cb> to check the results.
1064		1249
1065	See C<poll_cb> for an example.	1250	See C<poll_cb> for an example.
1066		1251
1067	=item IO::AIO::poll_cb	1252	=item IO::AIO::poll_cb
1068		1253
1069	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
1070	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
1071	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
1072	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>.
1073		1259
1074	If not all requests were processed for whatever reason, the filehandle	1260	If not all requests were processed for whatever reason, the filehandle
1075	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.
1076		1263
1077	Example: Install an Event watcher that automatically calls	1264	Example: Install an Event watcher that automatically calls
1078	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):
1079		1267
1080	Event->io (fd => IO::AIO::poll_fileno,	1268	Event->io (fd => IO::AIO::poll_fileno,
1081	poll => 'r', async => 1,	1269	poll => 'r', async => 1,
1082	cb => \&IO::AIO::poll_cb);	1270	cb => \&IO::AIO::poll_cb);
1083		1271
…		…
1194		1382
1195	The default is probably ok in most situations, especially if thread	1383	The default is probably ok in most situations, especially if thread
1196	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
1197	want to use larger values.	1385	want to use larger values.
1198		1386
1199	=item $oldmaxreqs = IO::AIO::max_outstanding $maxreqs	1387	=item IO::AIO::max_outstanding $maxreqs
1200		1388
1201	This is a very bad function to use in interactive programs because it	1389	This is a very bad function to use in interactive programs because it
1202	blocks, and a bad way to reduce concurrency because it is inexact: Better	1390	blocks, and a bad way to reduce concurrency because it is inexact: Better
1203	use an C<aio_group> together with a feed callback.	1391	use an C<aio_group> together with a feed callback.
1204		1392
1205	Sets the maximum number of outstanding requests to C<$nreqs>. If you	1393	Sets the maximum number of outstanding requests to C<$nreqs>. If you
1206	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
1207	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>)
1208	function will block until the limit is no longer exceeded.	1396	function will block until the limit is no longer exceeded.
1209		1397
1210	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
1211	number of outstanding requests.	1399	number of outstanding requests.
1212		1400
1213	You can still queue as many requests as you want. Therefore,	1401	You can still queue as many requests as you want. Therefore,
1214	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
1215	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).
1216		1404
1217	=back	1405	=back
1218		1406
1219	=head3 STATISTICAL INFORMATION	1407	=head3 STATISTICAL INFORMATION
…		…
1240	Returns the number of requests currently in the pending state (executed,	1428	Returns the number of requests currently in the pending state (executed,
1241	but not yet processed by poll_cb).	1429	but not yet processed by poll_cb).
1242		1430
1243	=back	1431	=back
1244		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
1245	=cut	1462	=cut
1246
1247	# support function to convert a fd into a perl filehandle
1248	sub _fd2fh {
1249	return undef if $_[0] < 0;
1250
1251	# try to generate nice filehandles
1252	my $sym = "IO::AIO::fd#$_[0]";
1253	local *$sym;
1254
1255	open *$sym, "+<&=$_[0]" # usually works under any unix
1256	or open *$sym, "<&=$_[0]" # cygwin needs this
1257	or open *$sym, ">&=$_[0]" # or this
1258	or return undef;
1259
1260	*$sym
1261	}
1262		1463
1263	min_parallel 8;	1464	min_parallel 8;
1264		1465
1265	END { flush }	1466	END { flush }
1266		1467
…		…
1290	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
1291	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
1292	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
1293	will consume memory till the request has entered the done state.	1494	will consume memory till the request has entered the done state.
1294		1495
1295	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
1296	problem.	1497	problem.
1297		1498
1298	Per-thread usage:	1499	Per-thread usage:
1299		1500
1300	In the execution phase, some aio requests require more memory for	1501	In the execution phase, some aio requests require more memory for
…		…
1305		1506
1306	Known bugs will be fixed in the next release.	1507	Known bugs will be fixed in the next release.
1307		1508
1308	=head1 SEE ALSO	1509	=head1 SEE ALSO
1309		1510
1310	L<Coro::AIO>.	1511	L<AnyEvent::AIO> for easy integration into event loops, L<Coro::AIO> for a
		1512	more natural syntax.
1311		1513
1312	=head1 AUTHOR	1514	=head1 AUTHOR
1313		1515
1314	Marc Lehmann <schmorp@schmorp.de>	1516	Marc Lehmann <schmorp@schmorp.de>
1315	http://home.schmorp.de/	1517	http://home.schmorp.de/

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Comparing IO-AIO/AIO.pm (file contents): Revision 1.109 by root, Sun Jun 3 09:44:17 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 1.109 by root, Sun Jun 3 09:44:17 2007 UTC vs.
Revision 1.171 by root, Sat Jan 2 14:24:32 2010 UTC