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

Comparing IO-AIO/AIO.pm (file contents):
Revision 1.108 by root, Fri Jun 1 13:25:50 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<$dataoffset>
331	callback without the actual number of bytes read (or -1 on error, just	345	and calls the callback without the actual number of bytes read (or -1 on
		346	error, just like the syscall).
		347
		348	C<aio_read> will, like C<sysread>, shrink or grow the C<$data> scalar to
		349	offset plus the actual number of bytes read.
		350
332	like the syscall). If C<offset> is undefined, then the current file offset	351	If C<$offset> is undefined, then the current file descriptor offset will
333	will be used (and updated), otherwise the file offset will not be changed	352	be used (and updated), otherwise the file descriptor offset will not be
334	by these calls.	353	changed by these calls.
		354
		355	If C<$length> is undefined in C<aio_write>, use the remaining length of
		356	C<$data>.
		357
		358	If C<$dataoffset> is less than zero, it will be counted from the end of
		359	C<$data>.
335		360
336	The C<$data> scalar I<MUST NOT> be modified in any way while the request	361	The C<$data> scalar I<MUST NOT> be modified in any way while the request
337	is outstanding. Modifying it can result in segfaults or World War III (if	362	is outstanding. Modifying it can result in segfaults or World War III (if
338	the necessary/optional hardware is installed).	363	the necessary/optional hardware is installed).
339		364
…		…
356		381
357	This call tries to make use of a native C<sendfile> syscall to provide	382	This call tries to make use of a native C<sendfile> syscall to provide
358	zero-copy operation. For this to work, C<$out_fh> should refer to a	383	zero-copy operation. For this to work, C<$out_fh> should refer to a
359	socket, and C<$in_fh> should refer to mmap'able file.	384	socket, and C<$in_fh> should refer to mmap'able file.
360		385
361	If the native sendfile call fails or is not implemented, it will be	386	If a native sendfile cannot be found or it fails with C<ENOSYS>,
		387	C<ENOTSUP>, C<EOPNOTSUPP>, C<EAFNOSUPPORT>, C<EPROTOTYPE> or C<ENOTSOCK>,
362	emulated, so you can call C<aio_sendfile> on any type of filehandle	388	it will be emulated, so you can call C<aio_sendfile> on any type of
363	regardless of the limitations of the operating system.	389	filehandle regardless of the limitations of the operating system.
364		390
365	Please note, however, that C<aio_sendfile> can read more bytes from	391	Please note, however, that C<aio_sendfile> can read more bytes from
366	C<$in_fh> than are written, and there is no way to find out how many	392	C<$in_fh> than are written, and there is no way to find out how many
367	bytes have been read from C<aio_sendfile> alone, as C<aio_sendfile> only	393	bytes have been read from C<aio_sendfile> alone, as C<aio_sendfile> only
368	provides the number of bytes written to C<$out_fh>. Only if the result	394	provides the number of bytes written to C<$out_fh>. Only if the result
…		…
437	aio_chown "path", 0, -1;	463	aio_chown "path", 0, -1;
438	# same as above:	464	# same as above:
439	aio_chown "path", 0, undef;	465	aio_chown "path", 0, undef;
440		466
441		467
		468	=item aio_truncate $fh_or_path, $offset, $callback->($status)
		469
		470	Works like truncate(2) or ftruncate(2).
		471
		472
442	=item aio_chmod $fh_or_path, $mode, $callback->($status)	473	=item aio_chmod $fh_or_path, $mode, $callback->($status)
443		474
444	Works like perl's C<chmod> function.	475	Works like perl's C<chmod> function.
445		476
446		477
…		…
503		534
504	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
505	directory (i.e. opendir + readdir + closedir). The entries will not be	536	directory (i.e. opendir + readdir + closedir). The entries will not be
506	sorted, and will B<NOT> include the C<.> and C<..> entries.	537	sorted, and will B<NOT> include the C<.> and C<..> entries.
507		538
508	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
509	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
510		607
511		608
512	=item aio_load $path, $data, $callback->($status)	609	=item aio_load $path, $data, $callback->($status)
513		610
514	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
515	memory. Status is the same as with aio_read.	612	memory. Status is the same as with aio_read.
516		613
517	=cut	614	=cut
518		615
519	sub aio_load($$;$) {	616	sub aio_load($$;$) {
520	aio_block {
521	my ($path, undef, $cb) = @_;	617	my ($path, undef, $cb) = @_;
522	my $data = \$_[1];	618	my $data = \$_[1];
523		619
524	my $pri = aioreq_pri;	620	my $pri = aioreq_pri;
525	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);
526		627
527	aioreq_pri $pri;	628	aioreq_pri $pri;
528	add $grp aio_open $path, O_RDONLY, 0, sub {
529	my $fh = shift
530	or return $grp->result (-1);
531
532	aioreq_pri $pri;
533	add $grp aio_read $fh, 0, (-s $fh), $$data, 0, sub {	629	add $grp aio_read $fh, 0, (-s $fh), $$data, 0, sub {
534	$grp->result ($_[0]);	630	$grp->result ($_[0]);
535	};
536	};	631	};
537
538	$grp
539	}	632	};
		633
		634	$grp
540	}	635	}
541		636
542	=item aio_copy $srcpath, $dstpath, $callback->($status)	637	=item aio_copy $srcpath, $dstpath, $callback->($status)
543		638
544	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
545	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
546	the C<0> (error) or C<-1> ok.	641	a status of C<0> (ok) or C<-1> (error, see C<$!>).
547		642
548	This is a composite request that it creates the destination file with	643	This is a composite request that creates the destination file with
549	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
550	C<aio_sendfile>, followed by restoring atime, mtime, access mode and	645	C<aio_sendfile>, followed by restoring atime, mtime, access mode and
551	uid/gid, in that order.	646	uid/gid, in that order.
552		647
553	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
…		…
555	errors are being ignored.	650	errors are being ignored.
556		651
557	=cut	652	=cut
558		653
559	sub aio_copy($$;$) {	654	sub aio_copy($$;$) {
560	aio_block {
561	my ($src, $dst, $cb) = @_;	655	my ($src, $dst, $cb) = @_;
562		656
563	my $pri = aioreq_pri;	657	my $pri = aioreq_pri;
564	my $grp = aio_group $cb;	658	my $grp = aio_group $cb;
565		659
566	aioreq_pri $pri;	660	aioreq_pri $pri;
567	add $grp aio_open $src, O_RDONLY, 0, sub {	661	add $grp aio_open $src, O_RDONLY, 0, sub {
568	if (my $src_fh = $_[0]) {	662	if (my $src_fh = $_[0]) {
569	my @stat = stat $src_fh;	663	my @stat = stat $src_fh; # hmm, might block over nfs?
570		664
571	aioreq_pri $pri;	665	aioreq_pri $pri;
572	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 {
573	if (my $dst_fh = $_[0]) {	667	if (my $dst_fh = $_[0]) {
574	aioreq_pri $pri;	668	aioreq_pri $pri;
575	add $grp aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub {	669	add $grp aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub {
576	if ($_[0] == $stat[7]) {	670	if ($_[0] == $stat[7]) {
577	$grp->result (0);	671	$grp->result (0);
578	close $src_fh;	672	close $src_fh;
579		673
580	# those should not normally block. should. should.
581	utime $stat[8], $stat[9], $dst;
582	chmod $stat[2] & 07777, $dst_fh;
583	chown $stat[4], $stat[5], $dst_fh;
584	close $dst_fh;
585	} else {	674	my $ch = sub {
586	$grp->result (-1);
587	close $src_fh;
588	close $dst_fh;
589
590	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;
591	add $grp aio_unlink $dst;	680	add $grp aio_close $dst_fh;
		681	}
		682	};
592	}	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;
593	};	701	}
594	} else {
595	$grp->result (-1);
596	}	702	};
		703	} else {
		704	$grp->result (-1);
597	},	705	}
598
599	} else {
600	$grp->result (-1);
601	}	706	},
		707
		708	} else {
		709	$grp->result (-1);
602	};	710	}
603
604	$grp
605	}	711	};
		712
		713	$grp
606	}	714	}
607		715
608	=item aio_move $srcpath, $dstpath, $callback->($status)	716	=item aio_move $srcpath, $dstpath, $callback->($status)
609		717
610	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
611	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
612	the C<0> (error) or C<-1> ok.	720	a status of C<0> (ok) or C<-1> (error, see C<$!>).
613		721
614	This is a composite request that tries to rename(2) the file first. If	722	This is a composite request that tries to rename(2) the file first; if
615	rename files with C<EXDEV>, it copies the file with C<aio_copy> and, if	723	rename fails with C<EXDEV>, it copies the file with C<aio_copy> and, if
616	that is successful, unlinking the C<$srcpath>.	724	that is successful, unlinks the C<$srcpath>.
617		725
618	=cut	726	=cut
619		727
620	sub aio_move($$;$) {	728	sub aio_move($$;$) {
621	aio_block {
622	my ($src, $dst, $cb) = @_;	729	my ($src, $dst, $cb) = @_;
623		730
624	my $pri = aioreq_pri;	731	my $pri = aioreq_pri;
625	my $grp = aio_group $cb;	732	my $grp = aio_group $cb;
626		733
627	aioreq_pri $pri;	734	aioreq_pri $pri;
628	add $grp aio_rename $src, $dst, sub {	735	add $grp aio_rename $src, $dst, sub {
629	if ($_[0] && $! == EXDEV) {	736	if ($_[0] && $! == EXDEV) {
630	aioreq_pri $pri;	737	aioreq_pri $pri;
631	add $grp aio_copy $src, $dst, sub {	738	add $grp aio_copy $src, $dst, sub {
632	$grp->result ($_[0]);
633
634	if (!$_[0]) {
635	aioreq_pri $pri;
636	add $grp aio_unlink $src;
637	}
638	};
639	} else {
640	$grp->result ($_[0]);	739	$grp->result ($_[0]);
		740
		741	if (!$_[0]) {
		742	aioreq_pri $pri;
		743	add $grp aio_unlink $src;
		744	}
641	}	745	};
		746	} else {
		747	$grp->result ($_[0]);
642	};	748	}
643
644	$grp
645	}	749	};
		750
		751	$grp
646	}	752	}
647		753
648	=item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs)	754	=item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs)
649		755
650	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
…		…
670		776
671	Implementation notes.	777	Implementation notes.
672		778
673	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.
674		780
		781	If readdir returns file type information, then this is used directly to
		782	find directories.
		783
675	After reading the directory, the modification time, size etc. of the	784	Otherwise, after reading the directory, the modification time, size etc.
676	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
677	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
678	entries are directories (if >= 2). Otherwise, no knowledge of the number	787	how many entries are directories (if >= 2). Otherwise, no knowledge of the
679	of subdirectories will be assumed.	788	number of subdirectories will be assumed.
680		789
681	Then entries will be sorted into likely directories (everything without	790	Then entries will be sorted into likely directories a non-initial dot
682	a non-initial dot currently) and likely non-directories (everything	791	currently) and likely non-directories (see C<aio_readdirx>). Then every
683	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,
684	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
685	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
686	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
687	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
688	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.
689		799
690	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
691	rest of the entries is assumed to be non-directories.	801	rest of the entries is assumed to be non-directories.
692		802
693	This only works with certainty on POSIX (= UNIX) filesystems, which	803	This only works with certainty on POSIX (= UNIX) filesystems, which
…		…
698	directory counting heuristic.	808	directory counting heuristic.
699		809
700	=cut	810	=cut
701		811
702	sub aio_scandir($$;$) {	812	sub aio_scandir($$;$) {
703	aio_block {
704	my ($path, $maxreq, $cb) = @_;	813	my ($path, $maxreq, $cb) = @_;
705		814
706	my $pri = aioreq_pri;	815	my $pri = aioreq_pri;
707		816
708	my $grp = aio_group $cb;	817	my $grp = aio_group $cb;
709		818
710	$maxreq = 4 if $maxreq <= 0;	819	$maxreq = 4 if $maxreq <= 0;
711		820
712	# 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
713	aioreq_pri $pri;	829	aioreq_pri $pri;
714	add $grp aio_stat $path, sub {	830	add $grp aio_readdirx $path, READDIR_DIRS_FIRST, sub {
		831	my $entries = shift
715	return $grp->result () if $_[0];	832	or return $grp->result ();
716	my $now = time;
717	my $hash1 = join ":", (stat _)[0,1,3,7,9];
718		833
719	# read the directory entries	834	# stat the dir another time
720	aioreq_pri $pri;	835	aioreq_pri $pri;
721	add $grp aio_readdir $path, sub {
722	my $entries = shift
723	or return $grp->result ();
724
725	# stat the dir another time
726	aioreq_pri $pri;
727	add $grp aio_stat $path, sub {	836	add $grp aio_stat $path, sub {
728	my $hash2 = join ":", (stat _)[0,1,3,7,9];	837	my $hash2 = join ":", (stat _)[0,1,3,7,9];
729		838
730	my $ndirs;	839	my $ndirs;
731		840
732	# take the slow route if anything looks fishy	841	# take the slow route if anything looks fishy
733	if ($hash1 ne $hash2 or (stat _)[9] == $now) {	842	if ($hash1 ne $hash2 or (stat _)[9] == $now) {
734	$ndirs = -1;	843	$ndirs = -1;
735	} else {	844	} else {
736	# if nlink == 2, we are finished	845	# if nlink == 2, we are finished
737	# on non-posix-fs's, we rely on nlink < 2	846	# for non-posix-fs's, we rely on nlink < 2
738	$ndirs = (stat _)[3] - 2	847	$ndirs = (stat _)[3] - 2
739	or return $grp->result ([], $entries);	848	or return $grp->result ([], $entries);
740	}	849	}
741		850
742	# sort into likely dirs and likely nondirs
743	# dirs == files without ".", short entries first
744	$entries = [map $_->[0],
745	sort { $b->[1] cmp $a->[1] }
746	map [$_, sprintf "%s%04d", (/.\./ ? "1" : "0"), length],
747	@$entries];
748
749	my (@dirs, @nondirs);	851	my (@dirs, @nondirs);
750		852
751	my $statgrp = add $grp aio_group sub {	853	my $statgrp = add $grp aio_group sub {
752	$grp->result (\@dirs, \@nondirs);	854	$grp->result (\@dirs, \@nondirs);
753	};	855	};
754		856
755	limit $statgrp $maxreq;	857	limit $statgrp $maxreq;
756	feed $statgrp sub {	858	feed $statgrp sub {
757	return unless @$entries;	859	return unless @$entries;
758	my $entry = pop @$entries;	860	my $entry = shift @$entries;
759		861
760	aioreq_pri $pri;	862	aioreq_pri $pri;
761	add $statgrp aio_stat "$path/$entry/.", sub {	863	add $statgrp aio_stat "$path/$entry/.", sub {
762	if ($_[0] < 0) {	864	if ($_[0] < 0) {
763	push @nondirs, $entry;	865	push @nondirs, $entry;
764	} else {	866	} else {
765	# need to check for real directory	867	# need to check for real directory
766	aioreq_pri $pri;	868	aioreq_pri $pri;
767	add $statgrp aio_lstat "$path/$entry", sub {	869	add $statgrp aio_lstat "$path/$entry", sub {
768	if (-d _) {	870	if (-d _) {
769	push @dirs, $entry;	871	push @dirs, $entry;
770		872
771	unless (--$ndirs) {	873	unless (--$ndirs) {
772	push @nondirs, @$entries;	874	push @nondirs, @$entries;
773	feed $statgrp;	875	feed $statgrp;
774	}
775	} else {
776	push @nondirs, $entry;
777	}	876	}
		877	} else {
		878	push @nondirs, $entry;
778	}	879	}
779	}	880	}
780	};	881	}
781	};	882	};
782	};	883	};
783	};	884	};
784	};	885	};
785
786	$grp
787	}	886	};
		887
		888	$grp
788	}	889	}
789		890
790	=item aio_rmtree $path, $callback->($status)	891	=item aio_rmtree $path, $callback->($status)
791		892
792	Delete a directory tree starting (and including) C<$path>, return the	893	Delete a directory tree starting (and including) C<$path>, return the
…		…
796		897
797	=cut	898	=cut
798		899
799	sub aio_rmtree;	900	sub aio_rmtree;
800	sub aio_rmtree($;$) {	901	sub aio_rmtree($;$) {
801	aio_block {
802	my ($path, $cb) = @_;	902	my ($path, $cb) = @_;
803		903
804	my $pri = aioreq_pri;	904	my $pri = aioreq_pri;
805	my $grp = aio_group $cb;	905	my $grp = aio_group $cb;
806		906
807	aioreq_pri $pri;	907	aioreq_pri $pri;
808	add $grp aio_scandir $path, 0, sub {	908	add $grp aio_scandir $path, 0, sub {
809	my ($dirs, $nondirs) = @_;	909	my ($dirs, $nondirs) = @_;
810		910
811	my $dirgrp = aio_group sub {	911	my $dirgrp = aio_group sub {
812	add $grp aio_rmdir $path, sub {	912	add $grp aio_rmdir $path, sub {
813	$grp->result ($_[0]);	913	$grp->result ($_[0]);
814	};
815	};	914	};
816
817	(aioreq_pri $pri), add $dirgrp aio_rmtree "$path/$_" for @$dirs;
818	(aioreq_pri $pri), add $dirgrp aio_unlink "$path/$_" for @$nondirs;
819
820	add $grp $dirgrp;
821	};	915	};
822		916
823	$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;
824	}	921	};
		922
		923	$grp
825	}	924	}
		925
		926	=item aio_sync $callback->($status)
		927
		928	Asynchronously call sync and call the callback when finished.
826		929
827	=item aio_fsync $fh, $callback->($status)	930	=item aio_fsync $fh, $callback->($status)
828		931
829	Asynchronously call fsync on the given filehandle and call the callback	932	Asynchronously call fsync on the given filehandle and call the callback
830	with the fsync result code.	933	with the fsync result code.
…		…
834	Asynchronously call fdatasync on the given filehandle and call the	937	Asynchronously call fdatasync on the given filehandle and call the
835	callback with the fdatasync result code.	938	callback with the fdatasync result code.
836		939
837	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
838	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).
839		1021
840	=item aio_group $callback->(...)	1022	=item aio_group $callback->(...)
841		1023
842	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
843	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
…		…
893	=item cancel $req	1075	=item cancel $req
894		1076
895	Cancels the request, if possible. Has the effect of skipping execution	1077	Cancels the request, if possible. Has the effect of skipping execution
896	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
897	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
898	untouched. That means that requests that currently execute will not be	1080	untouched (with the exception of readdir). That means that requests that
899	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.
900		1083
901	=item cb $req $callback->(...)	1084	=item cb $req $callback->(...)
902		1085
903	Replace (or simply set) the callback registered to the request.	1086	Replace (or simply set) the callback registered to the request.
904		1087
…		…
955	Their lifetime, simplified, looks like this: when they are empty, they	1138	Their lifetime, simplified, looks like this: when they are empty, they
956	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
957	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
958	exist.	1141	exist.
959		1142
960	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
961	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
962	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
963	itself finish.	1146	further requests to the group. And only when all those requests have
		1147	finished will the the group itself finish.
964		1148
965	=over 4	1149	=over 4
966		1150
967	=item add $grp ...	1151	=item add $grp ...
968		1152
…		…
977	=item $grp->cancel_subs	1161	=item $grp->cancel_subs
978		1162
979	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
980	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.
981		1165
		1166	The group request will finish normally (you cannot add requests to the
		1167	group).
		1168
982	=item $grp->result (...)	1169	=item $grp->result (...)
983		1170
984	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
985	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
986	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,
987	no argument will be passed and errno is zero.	1174	no argument will be passed and errno is zero.
988		1175
989	=item $grp->errno ([$errno])	1176	=item $grp->errno ([$errno])
990		1177
…		…
1001	=item feed $grp $callback->($grp)	1188	=item feed $grp $callback->($grp)
1002		1189
1003	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
1004	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,
1005	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,
1006	this might starve other requests for a potentially long time. For	1193	this might starve other requests for a potentially long time. For example,
1007	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,
1008	requests, delaying any later requests for a long time.	1195	delaying any later requests for a long time.
1009		1196
1010	To avoid this, and allow incremental generation of requests, you can	1197	To avoid this, and allow incremental generation of requests, you can
1011	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
1012	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>,
1013	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
…		…
1017	not impose any limits).	1204	not impose any limits).
1018		1205
1019	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
1020	automatically removed from the group.	1207	automatically removed from the group.
1021		1208
1022	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.
1023		1211
1024	Example:	1212	Example:
1025		1213
1026	# 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:
1027		1215
…		…
1039	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
1040	the group contains less than this many requests.	1228	the group contains less than this many requests.
1041		1229
1042	Setting the limit to C<0> will pause the feeding process.	1230	Setting the limit to C<0> will pause the feeding process.
1043		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
1044	=back	1235	=back
1045		1236
1046	=head2 SUPPORT FUNCTIONS	1237	=head2 SUPPORT FUNCTIONS
1047		1238
1048	=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION	1239	=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION
…		…
1050	=over 4	1241	=over 4
1051		1242
1052	=item $fileno = IO::AIO::poll_fileno	1243	=item $fileno = IO::AIO::poll_fileno
1053		1244
1054	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
1055	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,
1056	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
1057	to call C<poll_cb> to check the results.	1248	you have to call C<poll_cb> to check the results.
1058		1249
1059	See C<poll_cb> for an example.	1250	See C<poll_cb> for an example.
1060		1251
1061	=item IO::AIO::poll_cb	1252	=item IO::AIO::poll_cb
1062		1253
1063	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
1064	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
1065	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
1066	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>.
1067		1259
1068	If not all requests were processed for whatever reason, the filehandle	1260	If not all requests were processed for whatever reason, the filehandle
1069	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.
1070		1263
1071	Example: Install an Event watcher that automatically calls	1264	Example: Install an Event watcher that automatically calls
1072	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):
1073		1267
1074	Event->io (fd => IO::AIO::poll_fileno,	1268	Event->io (fd => IO::AIO::poll_fileno,
1075	poll => 'r', async => 1,	1269	poll => 'r', async => 1,
1076	cb => \&IO::AIO::poll_cb);	1270	cb => \&IO::AIO::poll_cb);
1077		1271
…		…
1188		1382
1189	The default is probably ok in most situations, especially if thread	1383	The default is probably ok in most situations, especially if thread
1190	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
1191	want to use larger values.	1385	want to use larger values.
1192		1386
1193	=item $oldmaxreqs = IO::AIO::max_outstanding $maxreqs	1387	=item IO::AIO::max_outstanding $maxreqs
1194		1388
1195	This is a very bad function to use in interactive programs because it	1389	This is a very bad function to use in interactive programs because it
1196	blocks, and a bad way to reduce concurrency because it is inexact: Better	1390	blocks, and a bad way to reduce concurrency because it is inexact: Better
1197	use an C<aio_group> together with a feed callback.	1391	use an C<aio_group> together with a feed callback.
1198		1392
1199	Sets the maximum number of outstanding requests to C<$nreqs>. If you	1393	Sets the maximum number of outstanding requests to C<$nreqs>. If you
1200	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
1201	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>)
1202	function will block until the limit is no longer exceeded.	1396	function will block until the limit is no longer exceeded.
1203		1397
1204	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
1205	number of outstanding requests.	1399	number of outstanding requests.
1206		1400
1207	You can still queue as many requests as you want. Therefore,	1401	You can still queue as many requests as you want. Therefore,
1208	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
1209	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).
1210		1404
1211	=back	1405	=back
1212		1406
1213	=head3 STATISTICAL INFORMATION	1407	=head3 STATISTICAL INFORMATION
…		…
1234	Returns the number of requests currently in the pending state (executed,	1428	Returns the number of requests currently in the pending state (executed,
1235	but not yet processed by poll_cb).	1429	but not yet processed by poll_cb).
1236		1430
1237	=back	1431	=back
1238		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
1239	=cut	1462	=cut
1240
1241	# support function to convert a fd into a perl filehandle
1242	sub _fd2fh {
1243	return undef if $_[0] < 0;
1244
1245	# try to generate nice filehandles
1246	my $sym = "IO::AIO::fd#$_[0]";
1247	local *$sym;
1248
1249	open *$sym, "+<&=$_[0]" # usually works under any unix
1250	or open *$sym, "<&=$_[0]" # cygwin needs this
1251	or open *$sym, ">&=$_[0]" # or this
1252	or return undef;
1253
1254	*$sym
1255	}
1256		1463
1257	min_parallel 8;	1464	min_parallel 8;
1258		1465
1259	END { flush }	1466	END { flush }
1260		1467
…		…
1284	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
1285	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
1286	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
1287	will consume memory till the request has entered the done state.	1494	will consume memory till the request has entered the done state.
1288		1495
1289	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
1290	problem.	1497	problem.
1291		1498
1292	Per-thread usage:	1499	Per-thread usage:
1293		1500
1294	In the execution phase, some aio requests require more memory for	1501	In the execution phase, some aio requests require more memory for
…		…
1299		1506
1300	Known bugs will be fixed in the next release.	1507	Known bugs will be fixed in the next release.
1301		1508
1302	=head1 SEE ALSO	1509	=head1 SEE ALSO
1303		1510
1304	L<Coro::AIO>.	1511	L<AnyEvent::AIO> for easy integration into event loops, L<Coro::AIO> for a
		1512	more natural syntax.
1305		1513
1306	=head1 AUTHOR	1514	=head1 AUTHOR
1307		1515
1308	Marc Lehmann <schmorp@schmorp.de>	1516	Marc Lehmann <schmorp@schmorp.de>
1309	http://home.schmorp.de/	1517	http://home.schmorp.de/

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Comparing IO-AIO/AIO.pm (file contents): Revision 1.108 by root, Fri Jun 1 13:25:50 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 1.108 by root, Fri Jun 1 13:25:50 2007 UTC vs.
Revision 1.171 by root, Sat Jan 2 14:24:32 2010 UTC