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

Comparing IO-AIO/AIO.pm (file contents):
Revision 1.106 by root, Fri Jun 1 05:51:21 2007 UTC vs.
Revision 1.172 by root, Thu Jan 7 18:08:21 2010 UTC

…		…
26	$req->cancel; # cancel request if still in queue	26	$req->cancel; # cancel request if still in queue
27		27
28	my $grp = aio_group sub { print "all stats done\n" };	28	my $grp = aio_group sub { print "all stats done\n" };
29	add $grp aio_stat "..." for ...;	29	add $grp aio_stat "..." for ...;
30		30
		31	# AnyEvent integration (EV, Event, Glib, Tk, POE, urxvt, pureperl...)
		32	use AnyEvent::AIO;
		33
31	# AnyEvent integration	34	# EV integration
32	open my $fh, "<&=" . IO::AIO::poll_fileno or die "$!";	35	my $aio_w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb;
33	my $w = AnyEvent->io (fh => $fh, poll => 'r', cb => sub { IO::AIO::poll_cb });
34		36
35	# Event integration	37	# Event integration
36	Event->io (fd => IO::AIO::poll_fileno,	38	Event->io (fd => IO::AIO::poll_fileno,
37	poll => 'r',	39	poll => 'r',
38	cb => \&IO::AIO::poll_cb);	40	cb => \&IO::AIO::poll_cb);
…		…
50	\&IO::AIO::poll_cb);	52	\&IO::AIO::poll_cb);
51		53
52	=head1 DESCRIPTION	54	=head1 DESCRIPTION
53		55
54	This module implements asynchronous I/O using whatever means your	56	This module implements asynchronous I/O using whatever means your
55	operating system supports.	57	operating system supports. It is implemented as an interface to C<libeio>
		58	(L<http://software.schmorp.de/pkg/libeio.html>).
56		59
57	Asynchronous means that operations that can normally block your program	60	Asynchronous means that operations that can normally block your program
58	(e.g. reading from disk) will be done asynchronously: the operation	61	(e.g. reading from disk) will be done asynchronously: the operation
59	will still block, but you can do something else in the meantime. This	62	will still block, but you can do something else in the meantime. This
60	is extremely useful for programs that need to stay interactive even	63	is extremely useful for programs that need to stay interactive even
…		…
62	etc.), but can also be used to easily do operations in parallel that are	65	etc.), but can also be used to easily do operations in parallel that are
63	normally done sequentially, e.g. stat'ing many files, which is much faster	66	normally done sequentially, e.g. stat'ing many files, which is much faster
64	on a RAID volume or over NFS when you do a number of stat operations	67	on a RAID volume or over NFS when you do a number of stat operations
65	concurrently.	68	concurrently.
66		69
67	While most of this works on all types of file descriptors (for example	70	While most of this works on all types of file descriptors (for
68	sockets), using these functions on file descriptors that support	71	example sockets), using these functions on file descriptors that
69	nonblocking operation (again, sockets, pipes etc.) is very inefficient or	72	support nonblocking operation (again, sockets, pipes etc.) is
70	might not work (aio_read fails on sockets/pipes/fifos). Use an event loop	73	very inefficient. Use an event loop for that (such as the L<EV>
71	for that (such as the L<Event\|Event> module): IO::AIO will naturally fit	74	module): IO::AIO will naturally fit into such an event loop itself.
72	into such an event loop itself.
73		75
74	In this version, a number of threads are started that execute your	76	In this version, a number of threads are started that execute your
75	requests and signal their completion. You don't need thread support	77	requests and signal their completion. You don't need thread support
76	in perl, and the threads created by this module will not be visible	78	in perl, and the threads created by this module will not be visible
77	to perl. In the future, this module might make use of the native aio	79	to perl. In the future, this module might make use of the native aio
…		…
79	not well-supported or restricted (GNU/Linux doesn't allow them on normal	81	not well-supported or restricted (GNU/Linux doesn't allow them on normal
80	files currently, for example), and they would only support aio_read and	82	files currently, for example), and they would only support aio_read and
81	aio_write, so the remaining functionality would have to be implemented	83	aio_write, so the remaining functionality would have to be implemented
82	using threads anyway.	84	using threads anyway.
83		85
84	Although the module will work with in the presence of other (Perl-)	86	Although the module will work in the presence of other (Perl-) threads,
85	threads, it is currently not reentrant in any way, so use appropriate	87	it is currently not reentrant in any way, so use appropriate locking
86	locking yourself, always call C<poll_cb> from within the same thread, or	88	yourself, always call C<poll_cb> from within the same thread, or never
87	never call C<poll_cb> (or other C<aio_> functions) recursively.	89	call C<poll_cb> (or other C<aio_> functions) recursively.
88		90
89	=head2 EXAMPLE	91	=head2 EXAMPLE
90		92
91	This is a simple example that uses the Event module and loads	93	This is a simple example that uses the EV module and loads
92	F</etc/passwd> asynchronously:	94	F</etc/passwd> asynchronously:
93		95
94	use Fcntl;	96	use Fcntl;
95	use Event;	97	use EV;
96	use IO::AIO;	98	use IO::AIO;
97		99
98	# register the IO::AIO callback with Event	100	# register the IO::AIO callback with EV
99	Event->io (fd => IO::AIO::poll_fileno,	101	my $aio_w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb;
100	poll => 'r',
101	cb => \&IO::AIO::poll_cb);
102		102
103	# queue the request to open /etc/passwd	103	# queue the request to open /etc/passwd
104	aio_open "/etc/passwd", O_RDONLY, 0, sub {	104	aio_open "/etc/passwd", O_RDONLY, 0, sub {
105	my $fh = shift	105	my $fh = shift
106	or die "error while opening: $!";	106	or die "error while opening: $!";
…		…
118		118
119	# file contents now in $contents	119	# file contents now in $contents
120	print $contents;	120	print $contents;
121		121
122	# exit event loop and program	122	# exit event loop and program
123	Event::unloop;	123	EV::unloop;
124	};	124	};
125	};	125	};
126		126
127	# possibly queue up other requests, or open GUI windows,	127	# possibly queue up other requests, or open GUI windows,
128	# check for sockets etc. etc.	128	# check for sockets etc. etc.
129		129
130	# process events as long as there are some:	130	# process events as long as there are some:
131	Event::loop;	131	EV::loop;
132		132
133	=head1 REQUEST ANATOMY AND LIFETIME	133	=head1 REQUEST ANATOMY AND LIFETIME
134		134
135	Every C<aio_*> function creates a request. which is a C data structure not	135	Every C<aio_*> function creates a request. which is a C data structure not
136	directly visible to Perl.	136	directly visible to Perl.
…		…
184		184
185	=cut	185	=cut
186		186
187	package IO::AIO;	187	package IO::AIO;
188		188
189	no warnings;	189	use Carp ();
190	use strict 'vars';	190
		191	use common::sense;
191		192
192	use base 'Exporter';	193	use base 'Exporter';
193		194
194	BEGIN {	195	BEGIN {
195	our $VERSION = '2.4';	196	our $VERSION = '3.4';
196		197
197	our @AIO_REQ = qw(aio_sendfile aio_read aio_write aio_open aio_close aio_stat	198	our @AIO_REQ = qw(aio_sendfile aio_read aio_write aio_open aio_close
198	aio_lstat aio_unlink aio_rmdir aio_readdir aio_scandir aio_symlink	199	aio_stat aio_lstat aio_unlink aio_rmdir aio_readdir aio_readdirx
199	aio_readlink aio_fsync aio_fdatasync aio_readahead aio_rename aio_link	200	aio_scandir aio_symlink aio_readlink aio_sync aio_fsync
		201	aio_fdatasync aio_sync_file_range aio_pathsync aio_readahead
		202	aio_rename aio_link aio_move aio_copy aio_group
200	aio_move aio_copy aio_group aio_nop aio_mknod aio_load aio_rmtree aio_mkdir	203	aio_nop aio_mknod aio_load aio_rmtree aio_mkdir aio_chown
		204	aio_chmod aio_utime aio_truncate
201	aio_chown aio_chmod aio_utime);	205	aio_msync aio_mtouch aio_statvfs);
		206
202	our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice aio_block));	207	our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice));
203	our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush	208	our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush
204	min_parallel max_parallel max_idle	209	min_parallel max_parallel max_idle
205	nreqs nready npending nthreads	210	nreqs nready npending nthreads
206	max_poll_time max_poll_reqs);	211	max_poll_time max_poll_reqs
		212	sendfile fadvise);
		213
		214	push @AIO_REQ, qw(aio_busy); # not exported
207		215
208	@IO::AIO::GRP::ISA = 'IO::AIO::REQ';	216	@IO::AIO::GRP::ISA = 'IO::AIO::REQ';
209		217
210	require XSLoader;	218	require XSLoader;
211	XSLoader::load ("IO::AIO", $VERSION);	219	XSLoader::load ("IO::AIO", $VERSION);
…		…
218	All the C<aio_*> calls are more or less thin wrappers around the syscall	226	All the C<aio_*> calls are more or less thin wrappers around the syscall
219	with the same name (sans C<aio_>). The arguments are similar or identical,	227	with the same name (sans C<aio_>). The arguments are similar or identical,
220	and they all accept an additional (and optional) C<$callback> argument	228	and they all accept an additional (and optional) C<$callback> argument
221	which must be a code reference. This code reference will get called with	229	which must be a code reference. This code reference will get called with
222	the syscall return code (e.g. most syscalls return C<-1> on error, unlike	230	the syscall return code (e.g. most syscalls return C<-1> on error, unlike
223	perl, which usually delivers "false") as it's sole argument when the given	231	perl, which usually delivers "false") as its sole argument after the given
224	syscall has been executed asynchronously.	232	syscall has been executed asynchronously.
225		233
226	All functions expecting a filehandle keep a copy of the filehandle	234	All functions expecting a filehandle keep a copy of the filehandle
227	internally until the request has finished.	235	internally until the request has finished.
228		236
…		…
242	your pathnames to the locale (or other) encoding in effect in the user	250	your pathnames to the locale (or other) encoding in effect in the user
243	environment, d) use Glib::filename_from_unicode on unicode filenames or e)	251	environment, d) use Glib::filename_from_unicode on unicode filenames or e)
244	use something else to ensure your scalar has the correct contents.	252	use something else to ensure your scalar has the correct contents.
245		253
246	This works, btw. independent of the internal UTF-8 bit, which IO::AIO	254	This works, btw. independent of the internal UTF-8 bit, which IO::AIO
247	handles correctly wether it is set or not.	255	handles correctly whether it is set or not.
248		256
249	=over 4	257	=over 4
250		258
251	=item $prev_pri = aioreq_pri [$pri]	259	=item $prev_pri = aioreq_pri [$pri]
252		260
…		…
312		320
313		321
314	=item aio_close $fh, $callback->($status)	322	=item aio_close $fh, $callback->($status)
315		323
316	Asynchronously close a file and call the callback with the result	324	Asynchronously close a file and call the callback with the result
317	code. I<WARNING:> although accepted, you should not pass in a perl	325	code.
318	filehandle here, as perl will likely close the file descriptor another
319	time when the filehandle is destroyed. Normally, you can safely call perls
320	C<close> or just let filehandles go out of scope.
321		326
322	This is supposed to be a bug in the API, so that might change. It's	327	Unfortunately, you can't do this to perl. Perl I<insists> very strongly on
323	therefore best to avoid this function.	328	closing the file descriptor associated with the filehandle itself.
324		329
		330	Therefore, C<aio_close> will not close the filehandle - instead it will
		331	use dup2 to overwrite the file descriptor with the write-end of a pipe
		332	(the pipe fd will be created on demand and will be cached).
		333
		334	Or in other words: the file descriptor will be closed, but it will not be
		335	free for reuse until the perl filehandle is closed.
		336
		337	=cut
325		338
326	=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)	339	=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
327		340
328	=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)	341	=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
329		342
330	Reads or writes C<length> bytes from the specified C<fh> and C<offset>	343	Reads or writes C<$length> bytes from or to the specified C<$fh> and
331	into the scalar given by C<data> and offset C<dataoffset> and calls the	344	C<$offset> into the scalar given by C<$data> and offset C<$dataoffset>
332	callback without the actual number of bytes read (or -1 on error, just	345	and calls the callback without the actual number of bytes read (or -1 on
333	like the syscall).	346	error, just like the syscall).
		347
		348	C<aio_read> will, like C<sysread>, shrink or grow the C<$data> scalar to
		349	offset plus the actual number of bytes read.
		350
		351	If C<$offset> is undefined, then the current file descriptor offset will
		352	be used (and updated), otherwise the file descriptor offset will not be
		353	changed by these calls.
		354
		355	If C<$length> is undefined in C<aio_write>, use the remaining length of
		356	C<$data>.
		357
		358	If C<$dataoffset> is less than zero, it will be counted from the end of
		359	C<$data>.
334		360
335	The C<$data> scalar I<MUST NOT> be modified in any way while the request	361	The C<$data> scalar I<MUST NOT> be modified in any way while the request
336	is outstanding. Modifying it can result in segfaults or WW3 (if the	362	is outstanding. Modifying it can result in segfaults or World War III (if
337	necessary/optional hardware is installed).	363	the necessary/optional hardware is installed).
338		364
339	Example: Read 15 bytes at offset 7 into scalar C<$buffer>, starting at	365	Example: Read 15 bytes at offset 7 into scalar C<$buffer>, starting at
340	offset C<0> within the scalar:	366	offset C<0> within the scalar:
341		367
342	aio_read $fh, 7, 15, $buffer, 0, sub {	368	aio_read $fh, 7, 15, $buffer, 0, sub {
…		…
355		381
356	This call tries to make use of a native C<sendfile> syscall to provide	382	This call tries to make use of a native C<sendfile> syscall to provide
357	zero-copy operation. For this to work, C<$out_fh> should refer to a	383	zero-copy operation. For this to work, C<$out_fh> should refer to a
358	socket, and C<$in_fh> should refer to mmap'able file.	384	socket, and C<$in_fh> should refer to mmap'able file.
359		385
360	If the native sendfile call fails or is not implemented, it will be	386	If a native sendfile cannot be found or it fails with C<ENOSYS>,
		387	C<ENOTSUP>, C<EOPNOTSUPP>, C<EAFNOSUPPORT>, C<EPROTOTYPE> or C<ENOTSOCK>,
361	emulated, so you can call C<aio_sendfile> on any type of filehandle	388	it will be emulated, so you can call C<aio_sendfile> on any type of
362	regardless of the limitations of the operating system.	389	filehandle regardless of the limitations of the operating system.
363		390
364	Please note, however, that C<aio_sendfile> can read more bytes from	391	Please note, however, that C<aio_sendfile> can read more bytes from
365	C<$in_fh> than are written, and there is no way to find out how many	392	C<$in_fh> than are written, and there is no way to find out how many
366	bytes have been read from C<aio_sendfile> alone, as C<aio_sendfile> only	393	bytes have been read from C<aio_sendfile> alone, as C<aio_sendfile> only
367	provides the number of bytes written to C<$out_fh>. Only if the result	394	provides the number of bytes written to C<$out_fh>. Only if the result
…		…
405	$_[0] and die "stat failed: $!";	432	$_[0] and die "stat failed: $!";
406	print "size is ", -s _, "\n";	433	print "size is ", -s _, "\n";
407	};	434	};
408		435
409		436
		437	=item aio_statvfs $fh_or_path, $callback->($statvfs)
		438
		439	Works like the POSIX C<statvfs> or C<fstatvfs> syscalls, depending on
		440	whether a file handle or path was passed.
		441
		442	On success, the callback is passed a hash reference with the following
		443	members: C<bsize>, C<frsize>, C<blocks>, C<bfree>, C<bavail>, C<files>,
		444	C<ffree>, C<favail>, C<fsid>, C<flag> and C<namemax>. On failure, C<undef>
		445	is passed.
		446
		447	The following POSIX IO::AIO::ST_* constants are defined: C<ST_RDONLY> and
		448	C<ST_NOSUID>.
		449
		450	The following non-POSIX IO::AIO::ST_* flag masks are defined to
		451	their correct value when available, or to C<0> on systems that do
		452	not support them: C<ST_NODEV>, C<ST_NOEXEC>, C<ST_SYNCHRONOUS>,
		453	C<ST_MANDLOCK>, C<ST_WRITE>, C<ST_APPEND>, C<ST_IMMUTABLE>, C<ST_NOATIME>,
		454	C<ST_NODIRATIME> and C<ST_RELATIME>.
		455
		456	Example: stat C</wd> and dump out the data if successful.
		457
		458	aio_statvfs "/wd", sub {
		459	my $f = $_[0]
		460	or die "statvfs: $!";
		461
		462	use Data::Dumper;
		463	say Dumper $f;
		464	};
		465
		466	# result:
		467	{
		468	bsize => 1024,
		469	bfree => 4333064312,
		470	blocks => 10253828096,
		471	files => 2050765568,
		472	flag => 4096,
		473	favail => 2042092649,
		474	bavail => 4333064312,
		475	ffree => 2042092649,
		476	namemax => 255,
		477	frsize => 1024,
		478	fsid => 1810
		479	}
		480
		481
410	=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status)	482	=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
411		483
412	Works like perl's C<utime> function (including the special case of $atime	484	Works like perl's C<utime> function (including the special case of $atime
413	and $mtime being undef). Fractional times are supported if the underlying	485	and $mtime being undef). Fractional times are supported if the underlying
414	syscalls support them.	486	syscalls support them.
…		…
417	utime(2). If called on a file descriptor, uses futimes(2) if available,	489	utime(2). If called on a file descriptor, uses futimes(2) if available,
418	otherwise returns ENOSYS, so this is not portable.	490	otherwise returns ENOSYS, so this is not portable.
419		491
420	Examples:	492	Examples:
421		493
422	# set atime and mtime to current time:	494	# set atime and mtime to current time (basically touch(1)):
423	aio_utime "path", undef, undef;	495	aio_utime "path", undef, undef;
424	# set atime to current time and mtime to beginning of the epoch:	496	# set atime to current time and mtime to beginning of the epoch:
425	aio_utime "path", time, undef; # undef==0	497	aio_utime "path", time, undef; # undef==0
426		498
427		499
…		…
436	aio_chown "path", 0, -1;	508	aio_chown "path", 0, -1;
437	# same as above:	509	# same as above:
438	aio_chown "path", 0, undef;	510	aio_chown "path", 0, undef;
439		511
440		512
		513	=item aio_truncate $fh_or_path, $offset, $callback->($status)
		514
		515	Works like truncate(2) or ftruncate(2).
		516
		517
441	=item aio_chmod $fh_or_path, $mode, $callback->($status)	518	=item aio_chmod $fh_or_path, $mode, $callback->($status)
442		519
443	Works like perl's C<chmod> function.	520	Works like perl's C<chmod> function.
444		521
445		522
…		…
502		579
503	Unlike the POSIX call of the same name, C<aio_readdir> reads an entire	580	Unlike the POSIX call of the same name, C<aio_readdir> reads an entire
504	directory (i.e. opendir + readdir + closedir). The entries will not be	581	directory (i.e. opendir + readdir + closedir). The entries will not be
505	sorted, and will B<NOT> include the C<.> and C<..> entries.	582	sorted, and will B<NOT> include the C<.> and C<..> entries.
506		583
507	The callback a single argument which is either C<undef> or an array-ref	584	The callback is passed a single argument which is either C<undef> or an
508	with the filenames.	585	array-ref with the filenames.
		586
		587
		588	=item aio_readdirx $pathname, $flags, $callback->($entries, $flags)
		589
		590	Quite similar to C<aio_readdir>, but the C<$flags> argument allows to tune
		591	behaviour and output format. In case of an error, C<$entries> will be
		592	C<undef>.
		593
		594	The flags are a combination of the following constants, ORed together (the
		595	flags will also be passed to the callback, possibly modified):
		596
		597	=over 4
		598
		599	=item IO::AIO::READDIR_DENTS
		600
		601	When this flag is off, then the callback gets an arrayref with of names
		602	only (as with C<aio_readdir>), otherwise it gets an arrayref with
		603	C<[$name, $type, $inode]> arrayrefs, each describing a single directory
		604	entry in more detail.
		605
		606	C<$name> is the name of the entry.
		607
		608	C<$type> is one of the C<IO::AIO::DT_xxx> constants:
		609
		610	C<IO::AIO::DT_UNKNOWN>, C<IO::AIO::DT_FIFO>, C<IO::AIO::DT_CHR>, C<IO::AIO::DT_DIR>,
		611	C<IO::AIO::DT_BLK>, C<IO::AIO::DT_REG>, C<IO::AIO::DT_LNK>, C<IO::AIO::DT_SOCK>,
		612	C<IO::AIO::DT_WHT>.
		613
		614	C<IO::AIO::DT_UNKNOWN> means just that: readdir does not know. If you need to
		615	know, you have to run stat yourself. Also, for speed reasons, the C<$type>
		616	scalars are read-only: you can not modify them.
		617
		618	C<$inode> is the inode number (which might not be exact on systems with 64
		619	bit inode numbers and 32 bit perls). This field has unspecified content on
		620	systems that do not deliver the inode information.
		621
		622	=item IO::AIO::READDIR_DIRS_FIRST
		623
		624	When this flag is set, then the names will be returned in an order where
		625	likely directories come first. This is useful when you need to quickly
		626	find directories, or you want to find all directories while avoiding to
		627	stat() each entry.
		628
		629	If the system returns type information in readdir, then this is used
		630	to find directories directly. Otherwise, likely directories are files
		631	beginning with ".", or otherwise files with no dots, of which files with
		632	short names are tried first.
		633
		634	=item IO::AIO::READDIR_STAT_ORDER
		635
		636	When this flag is set, then the names will be returned in an order
		637	suitable for stat()'ing each one. That is, when you plan to stat()
		638	all files in the given directory, then the returned order will likely
		639	be fastest.
		640
		641	If both this flag and C<IO::AIO::READDIR_DIRS_FIRST> are specified, then
		642	the likely dirs come first, resulting in a less optimal stat order.
		643
		644	=item IO::AIO::READDIR_FOUND_UNKNOWN
		645
		646	This flag should not be set when calling C<aio_readdirx>. Instead, it
		647	is being set by C<aio_readdirx>, when any of the C<$type>'s found were
		648	C<IO::AIO::DT_UNKNOWN>. The absense of this flag therefore indicates that all
		649	C<$type>'s are known, which can be used to speed up some algorithms.
		650
		651	=back
509		652
510		653
511	=item aio_load $path, $data, $callback->($status)	654	=item aio_load $path, $data, $callback->($status)
512		655
513	This is a composite request that tries to fully load the given file into	656	This is a composite request that tries to fully load the given file into
514	memory. Status is the same as with aio_read.	657	memory. Status is the same as with aio_read.
515		658
516	=cut	659	=cut
517		660
518	sub aio_load($$;$) {	661	sub aio_load($$;$) {
519	aio_block {
520	my ($path, undef, $cb) = @_;	662	my ($path, undef, $cb) = @_;
521	my $data = \$_[1];	663	my $data = \$_[1];
522		664
523	my $pri = aioreq_pri;	665	my $pri = aioreq_pri;
524	my $grp = aio_group $cb;	666	my $grp = aio_group $cb;
		667
		668	aioreq_pri $pri;
		669	add $grp aio_open $path, O_RDONLY, 0, sub {
		670	my $fh = shift
		671	or return $grp->result (-1);
525		672
526	aioreq_pri $pri;	673	aioreq_pri $pri;
527	add $grp aio_open $path, O_RDONLY, 0, sub {
528	my $fh = shift
529	or return $grp->result (-1);
530
531	aioreq_pri $pri;
532	add $grp aio_read $fh, 0, (-s $fh), $$data, 0, sub {	674	add $grp aio_read $fh, 0, (-s $fh), $$data, 0, sub {
533	$grp->result ($_[0]);	675	$grp->result ($_[0]);
534	};
535	};	676	};
536
537	$grp
538	}	677	};
		678
		679	$grp
539	}	680	}
540		681
541	=item aio_copy $srcpath, $dstpath, $callback->($status)	682	=item aio_copy $srcpath, $dstpath, $callback->($status)
542		683
543	Try to copy the I<file> (directories not supported as either source or	684	Try to copy the I<file> (directories not supported as either source or
544	destination) from C<$srcpath> to C<$dstpath> and call the callback with	685	destination) from C<$srcpath> to C<$dstpath> and call the callback with
545	the C<0> (error) or C<-1> ok.	686	a status of C<0> (ok) or C<-1> (error, see C<$!>).
546		687
547	This is a composite request that it creates the destination file with	688	This is a composite request that creates the destination file with
548	mode 0200 and copies the contents of the source file into it using	689	mode 0200 and copies the contents of the source file into it using
549	C<aio_sendfile>, followed by restoring atime, mtime, access mode and	690	C<aio_sendfile>, followed by restoring atime, mtime, access mode and
550	uid/gid, in that order.	691	uid/gid, in that order.
551		692
552	If an error occurs, the partial destination file will be unlinked, if	693	If an error occurs, the partial destination file will be unlinked, if
…		…
554	errors are being ignored.	695	errors are being ignored.
555		696
556	=cut	697	=cut
557		698
558	sub aio_copy($$;$) {	699	sub aio_copy($$;$) {
559	aio_block {
560	my ($src, $dst, $cb) = @_;	700	my ($src, $dst, $cb) = @_;
561		701
562	my $pri = aioreq_pri;	702	my $pri = aioreq_pri;
563	my $grp = aio_group $cb;	703	my $grp = aio_group $cb;
564		704
565	aioreq_pri $pri;	705	aioreq_pri $pri;
566	add $grp aio_open $src, O_RDONLY, 0, sub {	706	add $grp aio_open $src, O_RDONLY, 0, sub {
567	if (my $src_fh = $_[0]) {	707	if (my $src_fh = $_[0]) {
568	my @stat = stat $src_fh;	708	my @stat = stat $src_fh; # hmm, might block over nfs?
569		709
570	aioreq_pri $pri;	710	aioreq_pri $pri;
571	add $grp aio_open $dst, O_CREAT \| O_WRONLY \| O_TRUNC, 0200, sub {	711	add $grp aio_open $dst, O_CREAT \| O_WRONLY \| O_TRUNC, 0200, sub {
572	if (my $dst_fh = $_[0]) {	712	if (my $dst_fh = $_[0]) {
573	aioreq_pri $pri;	713	aioreq_pri $pri;
574	add $grp aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub {	714	add $grp aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub {
575	if ($_[0] == $stat[7]) {	715	if ($_[0] == $stat[7]) {
576	$grp->result (0);	716	$grp->result (0);
577	close $src_fh;	717	close $src_fh;
578		718
579	# those should not normally block. should. should.
580	utime $stat[8], $stat[9], $dst;
581	chmod $stat[2] & 07777, $dst_fh;
582	chown $stat[4], $stat[5], $dst_fh;
583	close $dst_fh;
584	} else {	719	my $ch = sub {
585	$grp->result (-1);
586	close $src_fh;
587	close $dst_fh;
588
589	aioreq $pri;	720	aioreq_pri $pri;
		721	add $grp aio_chmod $dst_fh, $stat[2] & 07777, sub {
		722	aioreq_pri $pri;
		723	add $grp aio_chown $dst_fh, $stat[4], $stat[5], sub {
		724	aioreq_pri $pri;
590	add $grp aio_unlink $dst;	725	add $grp aio_close $dst_fh;
		726	}
		727	};
591	}	728	};
		729
		730	aioreq_pri $pri;
		731	add $grp aio_utime $dst_fh, $stat[8], $stat[9], sub {
		732	if ($_[0] < 0 && $! == ENOSYS) {
		733	aioreq_pri $pri;
		734	add $grp aio_utime $dst, $stat[8], $stat[9], $ch;
		735	} else {
		736	$ch->();
		737	}
		738	};
		739	} else {
		740	$grp->result (-1);
		741	close $src_fh;
		742	close $dst_fh;
		743
		744	aioreq $pri;
		745	add $grp aio_unlink $dst;
592	};	746	}
593	} else {
594	$grp->result (-1);
595	}	747	};
		748	} else {
		749	$grp->result (-1);
596	},	750	}
597
598	} else {
599	$grp->result (-1);
600	}	751	},
		752
		753	} else {
		754	$grp->result (-1);
601	};	755	}
602
603	$grp
604	}	756	};
		757
		758	$grp
605	}	759	}
606		760
607	=item aio_move $srcpath, $dstpath, $callback->($status)	761	=item aio_move $srcpath, $dstpath, $callback->($status)
608		762
609	Try to move the I<file> (directories not supported as either source or	763	Try to move the I<file> (directories not supported as either source or
610	destination) from C<$srcpath> to C<$dstpath> and call the callback with	764	destination) from C<$srcpath> to C<$dstpath> and call the callback with
611	the C<0> (error) or C<-1> ok.	765	a status of C<0> (ok) or C<-1> (error, see C<$!>).
612		766
613	This is a composite request that tries to rename(2) the file first. If	767	This is a composite request that tries to rename(2) the file first; if
614	rename files with C<EXDEV>, it copies the file with C<aio_copy> and, if	768	rename fails with C<EXDEV>, it copies the file with C<aio_copy> and, if
615	that is successful, unlinking the C<$srcpath>.	769	that is successful, unlinks the C<$srcpath>.
616		770
617	=cut	771	=cut
618		772
619	sub aio_move($$;$) {	773	sub aio_move($$;$) {
620	aio_block {
621	my ($src, $dst, $cb) = @_;	774	my ($src, $dst, $cb) = @_;
622		775
623	my $pri = aioreq_pri;	776	my $pri = aioreq_pri;
624	my $grp = aio_group $cb;	777	my $grp = aio_group $cb;
625		778
626	aioreq_pri $pri;	779	aioreq_pri $pri;
627	add $grp aio_rename $src, $dst, sub {	780	add $grp aio_rename $src, $dst, sub {
628	if ($_[0] && $! == EXDEV) {	781	if ($_[0] && $! == EXDEV) {
629	aioreq_pri $pri;	782	aioreq_pri $pri;
630	add $grp aio_copy $src, $dst, sub {	783	add $grp aio_copy $src, $dst, sub {
631	$grp->result ($_[0]);
632
633	if (!$_[0]) {
634	aioreq_pri $pri;
635	add $grp aio_unlink $src;
636	}
637	};
638	} else {
639	$grp->result ($_[0]);	784	$grp->result ($_[0]);
		785
		786	if (!$_[0]) {
		787	aioreq_pri $pri;
		788	add $grp aio_unlink $src;
		789	}
640	}	790	};
		791	} else {
		792	$grp->result ($_[0]);
641	};	793	}
642
643	$grp
644	}	794	};
		795
		796	$grp
645	}	797	}
646		798
647	=item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs)	799	=item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs)
648		800
649	Scans a directory (similar to C<aio_readdir>) but additionally tries to	801	Scans a directory (similar to C<aio_readdir>) but additionally tries to
…		…
669		821
670	Implementation notes.	822	Implementation notes.
671		823
672	The C<aio_readdir> cannot be avoided, but C<stat()>'ing every entry can.	824	The C<aio_readdir> cannot be avoided, but C<stat()>'ing every entry can.
673		825
		826	If readdir returns file type information, then this is used directly to
		827	find directories.
		828
674	After reading the directory, the modification time, size etc. of the	829	Otherwise, after reading the directory, the modification time, size etc.
675	directory before and after the readdir is checked, and if they match (and	830	of the directory before and after the readdir is checked, and if they
676	isn't the current time), the link count will be used to decide how many	831	match (and isn't the current time), the link count will be used to decide
677	entries are directories (if >= 2). Otherwise, no knowledge of the number	832	how many entries are directories (if >= 2). Otherwise, no knowledge of the
678	of subdirectories will be assumed.	833	number of subdirectories will be assumed.
679		834
680	Then entries will be sorted into likely directories (everything without	835	Then entries will be sorted into likely directories a non-initial dot
681	a non-initial dot currently) and likely non-directories (everything	836	currently) and likely non-directories (see C<aio_readdirx>). Then every
682	else). Then every entry plus an appended C</.> will be C<stat>'ed,	837	entry plus an appended C</.> will be C<stat>'ed, likely directories first,
683	likely directories first. If that succeeds, it assumes that the entry	838	in order of their inode numbers. If that succeeds, it assumes that the
684	is a directory or a symlink to directory (which will be checked	839	entry is a directory or a symlink to directory (which will be checked
685	seperately). This is often faster than stat'ing the entry itself because	840	seperately). This is often faster than stat'ing the entry itself because
686	filesystems might detect the type of the entry without reading the inode	841	filesystems might detect the type of the entry without reading the inode
687	data (e.g. ext2fs filetype feature).	842	data (e.g. ext2fs filetype feature), even on systems that cannot return
		843	the filetype information on readdir.
688		844
689	If the known number of directories (link count - 2) has been reached, the	845	If the known number of directories (link count - 2) has been reached, the
690	rest of the entries is assumed to be non-directories.	846	rest of the entries is assumed to be non-directories.
691		847
692	This only works with certainty on POSIX (= UNIX) filesystems, which	848	This only works with certainty on POSIX (= UNIX) filesystems, which
…		…
697	directory counting heuristic.	853	directory counting heuristic.
698		854
699	=cut	855	=cut
700		856
701	sub aio_scandir($$;$) {	857	sub aio_scandir($$;$) {
702	aio_block {
703	my ($path, $maxreq, $cb) = @_;	858	my ($path, $maxreq, $cb) = @_;
704		859
705	my $pri = aioreq_pri;	860	my $pri = aioreq_pri;
706		861
707	my $grp = aio_group $cb;	862	my $grp = aio_group $cb;
708		863
709	$maxreq = 4 if $maxreq <= 0;	864	$maxreq = 4 if $maxreq <= 0;
710		865
711	# stat once	866	# stat once
		867	aioreq_pri $pri;
		868	add $grp aio_stat $path, sub {
		869	return $grp->result () if $_[0];
		870	my $now = time;
		871	my $hash1 = join ":", (stat _)[0,1,3,7,9];
		872
		873	# read the directory entries
712	aioreq_pri $pri;	874	aioreq_pri $pri;
713	add $grp aio_stat $path, sub {	875	add $grp aio_readdirx $path, READDIR_DIRS_FIRST, sub {
		876	my $entries = shift
714	return $grp->result () if $_[0];	877	or return $grp->result ();
715	my $now = time;
716	my $hash1 = join ":", (stat _)[0,1,3,7,9];
717		878
718	# read the directory entries	879	# stat the dir another time
719	aioreq_pri $pri;	880	aioreq_pri $pri;
720	add $grp aio_readdir $path, sub {
721	my $entries = shift
722	or return $grp->result ();
723
724	# stat the dir another time
725	aioreq_pri $pri;
726	add $grp aio_stat $path, sub {	881	add $grp aio_stat $path, sub {
727	my $hash2 = join ":", (stat _)[0,1,3,7,9];	882	my $hash2 = join ":", (stat _)[0,1,3,7,9];
728		883
729	my $ndirs;	884	my $ndirs;
730		885
731	# take the slow route if anything looks fishy	886	# take the slow route if anything looks fishy
732	if ($hash1 ne $hash2 or (stat _)[9] == $now) {	887	if ($hash1 ne $hash2 or (stat _)[9] == $now) {
733	$ndirs = -1;	888	$ndirs = -1;
734	} else {	889	} else {
735	# if nlink == 2, we are finished	890	# if nlink == 2, we are finished
736	# on non-posix-fs's, we rely on nlink < 2	891	# for non-posix-fs's, we rely on nlink < 2
737	$ndirs = (stat _)[3] - 2	892	$ndirs = (stat _)[3] - 2
738	or return $grp->result ([], $entries);	893	or return $grp->result ([], $entries);
739	}	894	}
740		895
741	# sort into likely dirs and likely nondirs
742	# dirs == files without ".", short entries first
743	$entries = [map $_->[0],
744	sort { $b->[1] cmp $a->[1] }
745	map [$_, sprintf "%s%04d", (/.\./ ? "1" : "0"), length],
746	@$entries];
747
748	my (@dirs, @nondirs);	896	my (@dirs, @nondirs);
749		897
750	my $statgrp = add $grp aio_group sub {	898	my $statgrp = add $grp aio_group sub {
751	$grp->result (\@dirs, \@nondirs);	899	$grp->result (\@dirs, \@nondirs);
752	};	900	};
753		901
754	limit $statgrp $maxreq;	902	limit $statgrp $maxreq;
755	feed $statgrp sub {	903	feed $statgrp sub {
756	return unless @$entries;	904	return unless @$entries;
757	my $entry = pop @$entries;	905	my $entry = shift @$entries;
758		906
759	aioreq_pri $pri;	907	aioreq_pri $pri;
760	add $statgrp aio_stat "$path/$entry/.", sub {	908	add $statgrp aio_stat "$path/$entry/.", sub {
761	if ($_[0] < 0) {	909	if ($_[0] < 0) {
762	push @nondirs, $entry;	910	push @nondirs, $entry;
763	} else {	911	} else {
764	# need to check for real directory	912	# need to check for real directory
765	aioreq_pri $pri;	913	aioreq_pri $pri;
766	add $statgrp aio_lstat "$path/$entry", sub {	914	add $statgrp aio_lstat "$path/$entry", sub {
767	if (-d _) {	915	if (-d _) {
768	push @dirs, $entry;	916	push @dirs, $entry;
769		917
770	unless (--$ndirs) {	918	unless (--$ndirs) {
771	push @nondirs, @$entries;	919	push @nondirs, @$entries;
772	feed $statgrp;	920	feed $statgrp;
773	}
774	} else {
775	push @nondirs, $entry;
776	}	921	}
		922	} else {
		923	push @nondirs, $entry;
777	}	924	}
778	}	925	}
779	};	926	}
780	};	927	};
781	};	928	};
782	};	929	};
783	};	930	};
784
785	$grp
786	}	931	};
		932
		933	$grp
787	}	934	}
788		935
789	=item aio_rmtree $path, $callback->($status)	936	=item aio_rmtree $path, $callback->($status)
790		937
791	Delete a directory tree starting (and including) C<$path>, return the	938	Delete a directory tree starting (and including) C<$path>, return the
…		…
795		942
796	=cut	943	=cut
797		944
798	sub aio_rmtree;	945	sub aio_rmtree;
799	sub aio_rmtree($;$) {	946	sub aio_rmtree($;$) {
800	aio_block {
801	my ($path, $cb) = @_;	947	my ($path, $cb) = @_;
802		948
803	my $pri = aioreq_pri;	949	my $pri = aioreq_pri;
804	my $grp = aio_group $cb;	950	my $grp = aio_group $cb;
805		951
806	aioreq_pri $pri;	952	aioreq_pri $pri;
807	add $grp aio_scandir $path, 0, sub {	953	add $grp aio_scandir $path, 0, sub {
808	my ($dirs, $nondirs) = @_;	954	my ($dirs, $nondirs) = @_;
809		955
810	my $dirgrp = aio_group sub {	956	my $dirgrp = aio_group sub {
811	add $grp aio_rmdir $path, sub {	957	add $grp aio_rmdir $path, sub {
812	$grp->result ($_[0]);	958	$grp->result ($_[0]);
813	};
814	};	959	};
815
816	(aioreq_pri $pri), add $dirgrp aio_rmtree "$path/$_" for @$dirs;
817	(aioreq_pri $pri), add $dirgrp aio_unlink "$path/$_" for @$nondirs;
818
819	add $grp $dirgrp;
820	};	960	};
821		961
822	$grp	962	(aioreq_pri $pri), add $dirgrp aio_rmtree "$path/$_" for @$dirs;
		963	(aioreq_pri $pri), add $dirgrp aio_unlink "$path/$_" for @$nondirs;
		964
		965	add $grp $dirgrp;
823	}	966	};
		967
		968	$grp
824	}	969	}
		970
		971	=item aio_sync $callback->($status)
		972
		973	Asynchronously call sync and call the callback when finished.
825		974
826	=item aio_fsync $fh, $callback->($status)	975	=item aio_fsync $fh, $callback->($status)
827		976
828	Asynchronously call fsync on the given filehandle and call the callback	977	Asynchronously call fsync on the given filehandle and call the callback
829	with the fsync result code.	978	with the fsync result code.
…		…
833	Asynchronously call fdatasync on the given filehandle and call the	982	Asynchronously call fdatasync on the given filehandle and call the
834	callback with the fdatasync result code.	983	callback with the fdatasync result code.
835		984
836	If this call isn't available because your OS lacks it or it couldn't be	985	If this call isn't available because your OS lacks it or it couldn't be
837	detected, it will be emulated by calling C<fsync> instead.	986	detected, it will be emulated by calling C<fsync> instead.
		987
		988	=item aio_sync_file_range $fh, $offset, $nbytes, $flags, $callback->($status)
		989
		990	Sync the data portion of the file specified by C<$offset> and C<$length>
		991	to disk (but NOT the metadata), by calling the Linux-specific
		992	sync_file_range call. If sync_file_range is not available or it returns
		993	ENOSYS, then fdatasync or fsync is being substituted.
		994
		995	C<$flags> can be a combination of C<IO::AIO::SYNC_FILE_RANGE_WAIT_BEFORE>,
		996	C<IO::AIO::SYNC_FILE_RANGE_WRITE> and
		997	C<IO::AIO::SYNC_FILE_RANGE_WAIT_AFTER>: refer to the sync_file_range
		998	manpage for details.
		999
		1000	=item aio_pathsync $path, $callback->($status)
		1001
		1002	This request tries to open, fsync and close the given path. This is a
		1003	composite request intended to sync directories after directory operations
		1004	(E.g. rename). This might not work on all operating systems or have any
		1005	specific effect, but usually it makes sure that directory changes get
		1006	written to disc. It works for anything that can be opened for read-only,
		1007	not just directories.
		1008
		1009	Future versions of this function might fall back to other methods when
		1010	C<fsync> on the directory fails (such as calling C<sync>).
		1011
		1012	Passes C<0> when everything went ok, and C<-1> on error.
		1013
		1014	=cut
		1015
		1016	sub aio_pathsync($;$) {
		1017	my ($path, $cb) = @_;
		1018
		1019	my $pri = aioreq_pri;
		1020	my $grp = aio_group $cb;
		1021
		1022	aioreq_pri $pri;
		1023	add $grp aio_open $path, O_RDONLY, 0, sub {
		1024	my ($fh) = @_;
		1025	if ($fh) {
		1026	aioreq_pri $pri;
		1027	add $grp aio_fsync $fh, sub {
		1028	$grp->result ($_[0]);
		1029
		1030	aioreq_pri $pri;
		1031	add $grp aio_close $fh;
		1032	};
		1033	} else {
		1034	$grp->result (-1);
		1035	}
		1036	};
		1037
		1038	$grp
		1039	}
		1040
		1041	=item aio_msync $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
		1042
		1043	This is a rather advanced IO::AIO call, which only works on mmap(2)ed
		1044	scalars (see the L<Sys::Mmap> or L<Mmap> modules for details on this, note
		1045	that the scalar must only be modified in-place while an aio operation is
		1046	pending on it).
		1047
		1048	It calls the C<msync> function of your OS, if available, with the memory
		1049	area starting at C<$offset> in the string and ending C<$length> bytes
		1050	later. If C<$length> is negative, counts from the end, and if C<$length>
		1051	is C<undef>, then it goes till the end of the string. The flags can be
		1052	a combination of C<IO::AIO::MS_ASYNC>, C<IO::AIO::MS_INVALIDATE> and
		1053	C<IO::AIO::MS_SYNC>.
		1054
		1055	=item aio_mtouch $scalar, $offset = 0, $length = undef, flags = 0, $callback->($status)
		1056
		1057	This is a rather advanced IO::AIO call, which works best on mmap(2)ed
		1058	scalars.
		1059
		1060	It touches (reads or writes) all memory pages in the specified
		1061	range inside the scalar. All caveats and parameters are the same
		1062	as for C<aio_msync>, above, except for flags, which must be either
		1063	C<0> (which reads all pages and ensures they are instantiated) or
		1064	C<IO::AIO::MT_MODIFY>, which modifies the memory page s(by reading and
		1065	writing an octet from it, which dirties the page).
838		1066
839	=item aio_group $callback->(...)	1067	=item aio_group $callback->(...)
840		1068
841	This is a very special aio request: Instead of doing something, it is a	1069	This is a very special aio request: Instead of doing something, it is a
842	container for other aio requests, which is useful if you want to bundle	1070	container for other aio requests, which is useful if you want to bundle
…		…
892	=item cancel $req	1120	=item cancel $req
893		1121
894	Cancels the request, if possible. Has the effect of skipping execution	1122	Cancels the request, if possible. Has the effect of skipping execution
895	when entering the B<execute> state and skipping calling the callback when	1123	when entering the B<execute> state and skipping calling the callback when
896	entering the the B<result> state, but will leave the request otherwise	1124	entering the the B<result> state, but will leave the request otherwise
897	untouched. That means that requests that currently execute will not be	1125	untouched (with the exception of readdir). That means that requests that
898	stopped and resources held by the request will not be freed prematurely.	1126	currently execute will not be stopped and resources held by the request
		1127	will not be freed prematurely.
899		1128
900	=item cb $req $callback->(...)	1129	=item cb $req $callback->(...)
901		1130
902	Replace (or simply set) the callback registered to the request.	1131	Replace (or simply set) the callback registered to the request.
903		1132
…		…
954	Their lifetime, simplified, looks like this: when they are empty, they	1183	Their lifetime, simplified, looks like this: when they are empty, they
955	will finish very quickly. If they contain only requests that are in the	1184	will finish very quickly. If they contain only requests that are in the
956	C<done> state, they will also finish. Otherwise they will continue to	1185	C<done> state, they will also finish. Otherwise they will continue to
957	exist.	1186	exist.
958		1187
959	That means after creating a group you have some time to add requests. And	1188	That means after creating a group you have some time to add requests
960	in the callbacks of those requests, you can add further requests to the	1189	(precisely before the callback has been invoked, which is only done within
961	group. And only when all those requests have finished will the the group	1190	the C<poll_cb>). And in the callbacks of those requests, you can add
962	itself finish.	1191	further requests to the group. And only when all those requests have
		1192	finished will the the group itself finish.
963		1193
964	=over 4	1194	=over 4
965		1195
966	=item add $grp ...	1196	=item add $grp ...
967		1197
…		…
976	=item $grp->cancel_subs	1206	=item $grp->cancel_subs
977		1207
978	Cancel all subrequests and clears any feeder, but not the group request	1208	Cancel all subrequests and clears any feeder, but not the group request
979	itself. Useful when you queued a lot of events but got a result early.	1209	itself. Useful when you queued a lot of events but got a result early.
980		1210
		1211	The group request will finish normally (you cannot add requests to the
		1212	group).
		1213
981	=item $grp->result (...)	1214	=item $grp->result (...)
982		1215
983	Set the result value(s) that will be passed to the group callback when all	1216	Set the result value(s) that will be passed to the group callback when all
984	subrequests have finished and set thre groups errno to the current value	1217	subrequests have finished and set the groups errno to the current value
985	of errno (just like calling C<errno> without an error number). By default,	1218	of errno (just like calling C<errno> without an error number). By default,
986	no argument will be passed and errno is zero.	1219	no argument will be passed and errno is zero.
987		1220
988	=item $grp->errno ([$errno])	1221	=item $grp->errno ([$errno])
989		1222
…		…
1000	=item feed $grp $callback->($grp)	1233	=item feed $grp $callback->($grp)
1001		1234
1002	Sets a feeder/generator on this group: every group can have an attached	1235	Sets a feeder/generator on this group: every group can have an attached
1003	generator that generates requests if idle. The idea behind this is that,	1236	generator that generates requests if idle. The idea behind this is that,
1004	although you could just queue as many requests as you want in a group,	1237	although you could just queue as many requests as you want in a group,
1005	this might starve other requests for a potentially long time. For	1238	this might starve other requests for a potentially long time. For example,
1006	example, C<aio_scandir> might generate hundreds of thousands C<aio_stat>	1239	C<aio_scandir> might generate hundreds of thousands C<aio_stat> requests,
1007	requests, delaying any later requests for a long time.	1240	delaying any later requests for a long time.
1008		1241
1009	To avoid this, and allow incremental generation of requests, you can	1242	To avoid this, and allow incremental generation of requests, you can
1010	instead a group and set a feeder on it that generates those requests. The	1243	instead a group and set a feeder on it that generates those requests. The
1011	feed callback will be called whenever there are few enough (see C<limit>,	1244	feed callback will be called whenever there are few enough (see C<limit>,
1012	below) requests active in the group itself and is expected to queue more	1245	below) requests active in the group itself and is expected to queue more
…		…
1016	not impose any limits).	1249	not impose any limits).
1017		1250
1018	If the feed does not queue more requests when called, it will be	1251	If the feed does not queue more requests when called, it will be
1019	automatically removed from the group.	1252	automatically removed from the group.
1020		1253
1021	If the feed limit is C<0>, it will be set to C<2> automatically.	1254	If the feed limit is C<0> when this method is called, it will be set to
		1255	C<2> automatically.
1022		1256
1023	Example:	1257	Example:
1024		1258
1025	# stat all files in @files, but only ever use four aio requests concurrently:	1259	# stat all files in @files, but only ever use four aio requests concurrently:
1026		1260
…		…
1038	Sets the feeder limit for the group: The feeder will be called whenever	1272	Sets the feeder limit for the group: The feeder will be called whenever
1039	the group contains less than this many requests.	1273	the group contains less than this many requests.
1040		1274
1041	Setting the limit to C<0> will pause the feeding process.	1275	Setting the limit to C<0> will pause the feeding process.
1042		1276
		1277	The default value for the limit is C<0>, but note that setting a feeder
		1278	automatically bumps it up to C<2>.
		1279
1043	=back	1280	=back
1044		1281
1045	=head2 SUPPORT FUNCTIONS	1282	=head2 SUPPORT FUNCTIONS
1046		1283
1047	=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION	1284	=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION
…		…
1049	=over 4	1286	=over 4
1050		1287
1051	=item $fileno = IO::AIO::poll_fileno	1288	=item $fileno = IO::AIO::poll_fileno
1052		1289
1053	Return the I<request result pipe file descriptor>. This filehandle must be	1290	Return the I<request result pipe file descriptor>. This filehandle must be
1054	polled for reading by some mechanism outside this module (e.g. Event or	1291	polled for reading by some mechanism outside this module (e.g. EV, Glib,
1055	select, see below or the SYNOPSIS). If the pipe becomes readable you have	1292	select and so on, see below or the SYNOPSIS). If the pipe becomes readable
1056	to call C<poll_cb> to check the results.	1293	you have to call C<poll_cb> to check the results.
1057		1294
1058	See C<poll_cb> for an example.	1295	See C<poll_cb> for an example.
1059		1296
1060	=item IO::AIO::poll_cb	1297	=item IO::AIO::poll_cb
1061		1298
1062	Process some outstanding events on the result pipe. You have to call this	1299	Process some outstanding events on the result pipe. You have to call this
1063	regularly. Returns the number of events processed. Returns immediately	1300	regularly. Returns C<0> if all events could be processed, or C<-1> if it
		1301	returned earlier for whatever reason. Returns immediately when no events
1064	when no events are outstanding. The amount of events processed depends on	1302	are outstanding. The amount of events processed depends on the settings of
1065	the settings of C<IO::AIO::max_poll_req> and C<IO::AIO::max_poll_time>.	1303	C<IO::AIO::max_poll_req> and C<IO::AIO::max_poll_time>.
1066		1304
1067	If not all requests were processed for whatever reason, the filehandle	1305	If not all requests were processed for whatever reason, the filehandle
1068	will still be ready when C<poll_cb> returns.	1306	will still be ready when C<poll_cb> returns, so normally you don't have to
		1307	do anything special to have it called later.
1069		1308
1070	Example: Install an Event watcher that automatically calls	1309	Example: Install an Event watcher that automatically calls
1071	IO::AIO::poll_cb with high priority:	1310	IO::AIO::poll_cb with high priority (more examples can be found in the
		1311	SYNOPSIS section, at the top of this document):
1072		1312
1073	Event->io (fd => IO::AIO::poll_fileno,	1313	Event->io (fd => IO::AIO::poll_fileno,
1074	poll => 'r', async => 1,	1314	poll => 'r', async => 1,
1075	cb => \&IO::AIO::poll_cb);	1315	cb => \&IO::AIO::poll_cb);
1076		1316
…		…
1187		1427
1188	The default is probably ok in most situations, especially if thread	1428	The default is probably ok in most situations, especially if thread
1189	creation is fast. If thread creation is very slow on your system you might	1429	creation is fast. If thread creation is very slow on your system you might
1190	want to use larger values.	1430	want to use larger values.
1191		1431
1192	=item $oldmaxreqs = IO::AIO::max_outstanding $maxreqs	1432	=item IO::AIO::max_outstanding $maxreqs
1193		1433
1194	This is a very bad function to use in interactive programs because it	1434	This is a very bad function to use in interactive programs because it
1195	blocks, and a bad way to reduce concurrency because it is inexact: Better	1435	blocks, and a bad way to reduce concurrency because it is inexact: Better
1196	use an C<aio_group> together with a feed callback.	1436	use an C<aio_group> together with a feed callback.
1197		1437
1198	Sets the maximum number of outstanding requests to C<$nreqs>. If you	1438	Sets the maximum number of outstanding requests to C<$nreqs>. If you
1199	to queue up more than this number of requests, the next call to the	1439	do queue up more than this number of requests, the next call to the
1200	C<poll_cb> (and C<poll_some> and other functions calling C<poll_cb>)	1440	C<poll_cb> (and C<poll_some> and other functions calling C<poll_cb>)
1201	function will block until the limit is no longer exceeded.	1441	function will block until the limit is no longer exceeded.
1202		1442
1203	The default value is very large, so there is no practical limit on the	1443	The default value is very large, so there is no practical limit on the
1204	number of outstanding requests.	1444	number of outstanding requests.
1205		1445
1206	You can still queue as many requests as you want. Therefore,	1446	You can still queue as many requests as you want. Therefore,
1207	C<max_oustsanding> is mainly useful in simple scripts (with low values) or	1447	C<max_outstanding> is mainly useful in simple scripts (with low values) or
1208	as a stop gap to shield against fatal memory overflow (with large values).	1448	as a stop gap to shield against fatal memory overflow (with large values).
1209		1449
1210	=back	1450	=back
1211		1451
1212	=head3 STATISTICAL INFORMATION	1452	=head3 STATISTICAL INFORMATION
…		…
1233	Returns the number of requests currently in the pending state (executed,	1473	Returns the number of requests currently in the pending state (executed,
1234	but not yet processed by poll_cb).	1474	but not yet processed by poll_cb).
1235		1475
1236	=back	1476	=back
1237		1477
		1478	=head3 MISCELLANEOUS FUNCTIONS
		1479
		1480	IO::AIO implements some functions that might be useful, but are not
		1481	asynchronous.
		1482
		1483	=over 4
		1484
		1485	=item IO::AIO::sendfile $ofh, $ifh, $offset, $count
		1486
		1487	Calls the C<eio_sendfile_sync> function, which is like C<aio_sendfile>,
		1488	but is blocking (this makes most sense if you know the input data is
		1489	likely cached already and the output filehandle is set to non-blocking
		1490	operations).
		1491
		1492	Returns the number of bytes copied, or C<-1> on error.
		1493
		1494	=item IO::AIO::fadvise $fh, $offset, $len, $advice
		1495
		1496	Simply calls the C<posix_fadvise> function (see it's
		1497	manpage for details). The following advice constants are
		1498	avaiable: C<IO::AIO::FADV_NORMAL>, C<IO::AIO::FADV_SEQUENTIAL>,
		1499	C<IO::AIO::FADV_RANDOM>, C<IO::AIO::FADV_NOREUSE>,
		1500	C<IO::AIO::FADV_WILLNEED>, C<IO::AIO::FADV_DONTNEED>.
		1501
		1502	On systems that do not implement C<posix_fadvise>, this function returns
		1503	ENOSYS, otherwise the return value of C<posix_fadvise>.
		1504
		1505	=back
		1506
1238	=cut	1507	=cut
1239
1240	# support function to convert a fd into a perl filehandle
1241	sub _fd2fh {
1242	return undef if $_[0] < 0;
1243
1244	# try to generate nice filehandles
1245	my $sym = "IO::AIO::fd#$_[0]";
1246	local *$sym;
1247
1248	open *$sym, "+<&=$_[0]" # usually works under any unix
1249	or open *$sym, "<&=$_[0]" # cygwin needs this
1250	or open *$sym, ">&=$_[0]" # or this
1251	or return undef;
1252
1253	*$sym
1254	}
1255		1508
1256	min_parallel 8;	1509	min_parallel 8;
1257		1510
1258	END { flush }	1511	END { flush }
1259		1512
…		…
1283	bytes of memory. In addition, stat requests need a stat buffer (possibly	1536	bytes of memory. In addition, stat requests need a stat buffer (possibly
1284	a few hundred bytes), readdir requires a result buffer and so on. Perl	1537	a few hundred bytes), readdir requires a result buffer and so on. Perl
1285	scalars and other data passed into aio requests will also be locked and	1538	scalars and other data passed into aio requests will also be locked and
1286	will consume memory till the request has entered the done state.	1539	will consume memory till the request has entered the done state.
1287		1540
1288	This is now awfully much, so queuing lots of requests is not usually a	1541	This is not awfully much, so queuing lots of requests is not usually a
1289	problem.	1542	problem.
1290		1543
1291	Per-thread usage:	1544	Per-thread usage:
1292		1545
1293	In the execution phase, some aio requests require more memory for	1546	In the execution phase, some aio requests require more memory for
…		…
1298		1551
1299	Known bugs will be fixed in the next release.	1552	Known bugs will be fixed in the next release.
1300		1553
1301	=head1 SEE ALSO	1554	=head1 SEE ALSO
1302		1555
1303	L<Coro::AIO>.	1556	L<AnyEvent::AIO> for easy integration into event loops, L<Coro::AIO> for a
		1557	more natural syntax.
1304		1558
1305	=head1 AUTHOR	1559	=head1 AUTHOR
1306		1560
1307	Marc Lehmann <schmorp@schmorp.de>	1561	Marc Lehmann <schmorp@schmorp.de>
1308	http://home.schmorp.de/	1562	http://home.schmorp.de/

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Comparing IO-AIO/AIO.pm (file contents): Revision 1.106 by root, Fri Jun 1 05:51:21 2007 UTC vs. Revision 1.172 by root, Thu Jan 7 18:08:21 2010 UTC

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Comparing IO-AIO/AIO.pm (file contents):
Revision 1.106 by root, Fri Jun 1 05:51:21 2007 UTC vs.
Revision 1.172 by root, Thu Jan 7 18:08:21 2010 UTC