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

Comparing IO-AIO/AIO.pm (file contents):
Revision 1.82 by root, Fri Oct 27 20:10:06 2006 UTC vs.
Revision 1.119 by root, Sun Dec 2 20:54:33 2007 UTC

…		…
5	=head1 SYNOPSIS	5	=head1 SYNOPSIS
6		6
7	use IO::AIO;	7	use IO::AIO;
8		8
9	aio_open "/etc/passwd", O_RDONLY, 0, sub {	9	aio_open "/etc/passwd", O_RDONLY, 0, sub {
10	my ($fh) = @_;	10	my $fh = shift
		11	or die "/etc/passwd: $!";
11	...	12	...
12	};	13	};
13		14
14	aio_unlink "/tmp/file", sub { };	15	aio_unlink "/tmp/file", sub { };
15		16
…		…
25	$req->cancel; # cancel request if still in queue	26	$req->cancel; # cancel request if still in queue
26		27
27	my $grp = aio_group sub { print "all stats done\n" };	28	my $grp = aio_group sub { print "all stats done\n" };
28	add $grp aio_stat "..." for ...;	29	add $grp aio_stat "..." for ...;
29		30
30	# AnyEvent integration	31	# AnyEvent integration (EV, Event, Glib, Tk, urxvt, pureperl...)
31	open my $fh, "<&=" . IO::AIO::poll_fileno or die "$!";	32	open my $fh, "<&=" . IO::AIO::poll_fileno or die "$!";
32	my $w = AnyEvent->io (fh => $fh, poll => 'r', cb => sub { IO::AIO::poll_cb });	33	my $w = AnyEvent->io (fh => $fh, poll => 'r', cb => sub { IO::AIO::poll_cb });
		34
		35	# EV integration
		36	my $w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb;
33		37
34	# Event integration	38	# Event integration
35	Event->io (fd => IO::AIO::poll_fileno,	39	Event->io (fd => IO::AIO::poll_fileno,
36	poll => 'r',	40	poll => 'r',
37	cb => \&IO::AIO::poll_cb);	41	cb => \&IO::AIO::poll_cb);
…		…
50		54
51	=head1 DESCRIPTION	55	=head1 DESCRIPTION
52		56
53	This module implements asynchronous I/O using whatever means your	57	This module implements asynchronous I/O using whatever means your
54	operating system supports.	58	operating system supports.
		59
		60	Asynchronous means that operations that can normally block your program
		61	(e.g. reading from disk) will be done asynchronously: the operation
		62	will still block, but you can do something else in the meantime. This
		63	is extremely useful for programs that need to stay interactive even
		64	when doing heavy I/O (GUI programs, high performance network servers
		65	etc.), but can also be used to easily do operations in parallel that are
		66	normally done sequentially, e.g. stat'ing many files, which is much faster
		67	on a RAID volume or over NFS when you do a number of stat operations
		68	concurrently.
		69
		70	While most of this works on all types of file descriptors (for
		71	example sockets), using these functions on file descriptors that
		72	support nonblocking operation (again, sockets, pipes etc.) is very
		73	inefficient. Use an event loop for that (such as the L<Event\|Event>
		74	module): IO::AIO will naturally fit into such an event loop itself.
55		75
56	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
57	requests and signal their completion. You don't need thread support	77	requests and signal their completion. You don't need thread support
58	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
59	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
60	functions available on many operating systems. However, they are often	80	functions available on many operating systems. However, they are often
61	not well-supported or restricted (Linux doesn't allow them on normal	81	not well-supported or restricted (GNU/Linux doesn't allow them on normal
62	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
63	aio_write, so the remaining functionality would have to be implemented	83	aio_write, so the remaining functionality would have to be implemented
64	using threads anyway.	84	using threads anyway.
65		85
66	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,
67	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
68	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
69	never call C<poll_cb> (or other C<aio_> functions) recursively.	89	call C<poll_cb> (or other C<aio_> functions) recursively.
		90
		91	=head2 EXAMPLE
		92
		93	This is a simple example that uses the Event module and loads
		94	F</etc/passwd> asynchronously:
		95
		96	use Fcntl;
		97	use Event;
		98	use IO::AIO;
		99
		100	# register the IO::AIO callback with Event
		101	Event->io (fd => IO::AIO::poll_fileno,
		102	poll => 'r',
		103	cb => \&IO::AIO::poll_cb);
		104
		105	# queue the request to open /etc/passwd
		106	aio_open "/etc/passwd", O_RDONLY, 0, sub {
		107	my $fh = shift
		108	or die "error while opening: $!";
		109
		110	# stat'ing filehandles is generally non-blocking
		111	my $size = -s $fh;
		112
		113	# queue a request to read the file
		114	my $contents;
		115	aio_read $fh, 0, $size, $contents, 0, sub {
		116	$_[0] == $size
		117	or die "short read: $!";
		118
		119	close $fh;
		120
		121	# file contents now in $contents
		122	print $contents;
		123
		124	# exit event loop and program
		125	Event::unloop;
		126	};
		127	};
		128
		129	# possibly queue up other requests, or open GUI windows,
		130	# check for sockets etc. etc.
		131
		132	# process events as long as there are some:
		133	Event::loop;
70		134
71	=head1 REQUEST ANATOMY AND LIFETIME	135	=head1 REQUEST ANATOMY AND LIFETIME
72		136
73	Every C<aio_*> function creates a request. which is a C data structure not	137	Every C<aio_*> function creates a request. which is a C data structure not
74	directly visible to Perl.	138	directly visible to Perl.
…		…
116	Request has reached the end of its lifetime and holds no resources anymore	180	Request has reached the end of its lifetime and holds no resources anymore
117	(except possibly for the Perl object, but its connection to the actual	181	(except possibly for the Perl object, but its connection to the actual
118	aio request is severed and calling its methods will either do nothing or	182	aio request is severed and calling its methods will either do nothing or
119	result in a runtime error).	183	result in a runtime error).
120		184
		185	=back
		186
121	=cut	187	=cut
122		188
123	package IO::AIO;	189	package IO::AIO;
		190
		191	use Carp ();
124		192
125	no warnings;	193	no warnings;
126	use strict 'vars';	194	use strict 'vars';
127		195
128	use base 'Exporter';	196	use base 'Exporter';
129		197
130	BEGIN {	198	BEGIN {
131	our $VERSION = '2.0';	199	our $VERSION = '2.6';
132		200
133	our @AIO_REQ = qw(aio_sendfile aio_read aio_write aio_open aio_close aio_stat	201	our @AIO_REQ = qw(aio_sendfile aio_read aio_write aio_open aio_close aio_stat
134	aio_lstat aio_unlink aio_rmdir aio_readdir aio_scandir aio_symlink	202	aio_lstat aio_unlink aio_rmdir aio_readdir aio_scandir aio_symlink
135	aio_fsync aio_fdatasync aio_readahead aio_rename aio_link aio_move	203	aio_readlink aio_sync aio_fsync aio_fdatasync aio_readahead aio_rename aio_link
136	aio_copy aio_group aio_nop aio_mknod);	204	aio_move aio_copy aio_group aio_nop aio_mknod aio_load aio_rmtree aio_mkdir
		205	aio_chown aio_chmod aio_utime aio_truncate);
137	our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice));	206	our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice aio_block));
138	our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush	207	our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush
139	min_parallel max_parallel nreqs nready npending);	208	min_parallel max_parallel max_idle
		209	nreqs nready npending nthreads
		210	max_poll_time max_poll_reqs);
140		211
141	@IO::AIO::GRP::ISA = 'IO::AIO::REQ';	212	@IO::AIO::GRP::ISA = 'IO::AIO::REQ';
142		213
143	require XSLoader;	214	require XSLoader;
144	XSLoader::load ("IO::AIO", $VERSION);	215	XSLoader::load ("IO::AIO", $VERSION);
145	}	216	}
146		217
147	=head1 FUNCTIONS	218	=head1 FUNCTIONS
148		219
149	=head2 AIO FUNCTIONS	220	=head2 AIO REQUEST FUNCTIONS
150		221
151	All the C<aio_*> calls are more or less thin wrappers around the syscall	222	All the C<aio_*> calls are more or less thin wrappers around the syscall
152	with the same name (sans C<aio_>). The arguments are similar or identical,	223	with the same name (sans C<aio_>). The arguments are similar or identical,
153	and they all accept an additional (and optional) C<$callback> argument	224	and they all accept an additional (and optional) C<$callback> argument
154	which must be a code reference. This code reference will get called with	225	which must be a code reference. This code reference will get called with
…		…
157	syscall has been executed asynchronously.	228	syscall has been executed asynchronously.
158		229
159	All functions expecting a filehandle keep a copy of the filehandle	230	All functions expecting a filehandle keep a copy of the filehandle
160	internally until the request has finished.	231	internally until the request has finished.
161		232
162	All requests return objects of type L<IO::AIO::REQ> that allow further	233	All functions return request objects of type L<IO::AIO::REQ> that allow
163	manipulation of those requests while they are in-flight.	234	further manipulation of those requests while they are in-flight.
164		235
165	The pathnames you pass to these routines I<must> be absolute and	236	The pathnames you pass to these routines I<must> be absolute and
166	encoded in byte form. The reason for the former is that at the time the	237	encoded as octets. The reason for the former is that at the time the
167	request is being executed, the current working directory could have	238	request is being executed, the current working directory could have
168	changed. Alternatively, you can make sure that you never change the	239	changed. Alternatively, you can make sure that you never change the
169	current working directory.	240	current working directory anywhere in the program and then use relative
		241	paths.
170		242
171	To encode pathnames to byte form, either make sure you either: a)	243	To encode pathnames as octets, either make sure you either: a) always pass
172	always pass in filenames you got from outside (command line, readdir	244	in filenames you got from outside (command line, readdir etc.) without
173	etc.), b) are ASCII or ISO 8859-1, c) use the Encode module and encode	245	tinkering, b) are ASCII or ISO 8859-1, c) use the Encode module and encode
174	your pathnames to the locale (or other) encoding in effect in the user	246	your pathnames to the locale (or other) encoding in effect in the user
175	environment, d) use Glib::filename_from_unicode on unicode filenames or e)	247	environment, d) use Glib::filename_from_unicode on unicode filenames or e)
176	use something else.	248	use something else to ensure your scalar has the correct contents.
		249
		250	This works, btw. independent of the internal UTF-8 bit, which IO::AIO
		251	handles correctly wether it is set or not.
177		252
178	=over 4	253	=over 4
179		254
180	=item $prev_pri = aioreq_pri [$pri]	255	=item $prev_pri = aioreq_pri [$pri]
181		256
…		…
201	aio_read $_[0], ..., sub {	276	aio_read $_[0], ..., sub {
202	...	277	...
203	};	278	};
204	};	279	};
205		280
		281
206	=item aioreq_nice $pri_adjust	282	=item aioreq_nice $pri_adjust
207		283
208	Similar to C<aioreq_pri>, but subtracts the given value from the current	284	Similar to C<aioreq_pri>, but subtracts the given value from the current
209	priority, so effects are cumulative.	285	priority, so the effect is cumulative.
		286
210		287
211	=item aio_open $pathname, $flags, $mode, $callback->($fh)	288	=item aio_open $pathname, $flags, $mode, $callback->($fh)
212		289
213	Asynchronously open or create a file and call the callback with a newly	290	Asynchronously open or create a file and call the callback with a newly
214	created filehandle for the file.	291	created filehandle for the file.
…		…
220	list. They are the same as used by C<sysopen>.	297	list. They are the same as used by C<sysopen>.
221		298
222	Likewise, C<$mode> specifies the mode of the newly created file, if it	299	Likewise, C<$mode> specifies the mode of the newly created file, if it
223	didn't exist and C<O_CREAT> has been given, just like perl's C<sysopen>,	300	didn't exist and C<O_CREAT> has been given, just like perl's C<sysopen>,
224	except that it is mandatory (i.e. use C<0> if you don't create new files,	301	except that it is mandatory (i.e. use C<0> if you don't create new files,
225	and C<0666> or C<0777> if you do).	302	and C<0666> or C<0777> if you do). Note that the C<$mode> will be modified
		303	by the umask in effect then the request is being executed, so better never
		304	change the umask.
226		305
227	Example:	306	Example:
228		307
229	aio_open "/etc/passwd", O_RDONLY, 0, sub {	308	aio_open "/etc/passwd", O_RDONLY, 0, sub {
230	if ($_[0]) {	309	if ($_[0]) {
…		…
233	} else {	312	} else {
234	die "open failed: $!\n";	313	die "open failed: $!\n";
235	}	314	}
236	};	315	};
237		316
		317
238	=item aio_close $fh, $callback->($status)	318	=item aio_close $fh, $callback->($status)
239		319
240	Asynchronously close a file and call the callback with the result	320	Asynchronously close a file and call the callback with the result
241	code. I<WARNING:> although accepted, you should not pass in a perl	321	code.
242	filehandle here, as perl will likely close the file descriptor another
243	time when the filehandle is destroyed. Normally, you can safely call perls
244	C<close> or just let filehandles go out of scope.
245		322
246	This is supposed to be a bug in the API, so that might change. It's	323	Unfortunately, you can't do this to perl. Perl I<insists> very strongly on
247	therefore best to avoid this function.	324	closing the file descriptor associated with the filehandle itself. Here is
		325	what aio_close will try:
		326
		327	1. dup()licate the fd
		328	2. asynchronously close() the duplicated fd
		329	3. dup()licate the fd once more
		330	4. let perl close() the filehandle
		331	5. asynchronously close the duplicated fd
		332
		333	The idea is that the first close() flushes stuff to disk that closing an
		334	fd will flush, so when perl closes the fd, nothing much will need to be
		335	flushed. The second async. close() will then flush stuff to disk that
		336	closing the last fd to the file will flush.
		337
		338	Just FYI, SuSv3 has this to say on close:
		339
		340	All outstanding record locks owned by the process on the file
		341	associated with the file descriptor shall be removed.
		342
		343	If fildes refers to a socket, close() shall cause the socket to be
		344	destroyed. ... close() shall block for up to the current linger
		345	interval until all data is transmitted.
		346	[this actually sounds like a specification bug, but who knows]
		347
		348	And at least Linux additionally actually flushes stuff on every close,
		349	even when the file itself is still open.
		350
		351	Sounds enourmously inefficient and complicated? Yes... please show me how
		352	to nuke perl's fd out of existence...
		353
		354	=cut
		355
		356	sub aio_close($;$) {
		357	aio_block {
		358	my ($fh, $cb) = @_;
		359
		360	my $pri = aioreq_pri;
		361	my $grp = aio_group $cb;
		362
		363	my $fd = fileno $fh;
		364
		365	defined $fd or Carp::croak "aio_close called with fd-less filehandle";
		366
		367	# if the dups fail we will simply get EBADF
		368	my $fd2 = _dup $fd;
		369	aioreq_pri $pri;
		370	add $grp _aio_close $fd2, sub {
		371	my $fd2 = _dup $fd;
		372	close $fh;
		373	aioreq_pri $pri;
		374	add $grp _aio_close $fd2, sub {
		375	$grp->result ($_[0]);
		376	};
		377	};
		378
		379	$grp
		380	}
		381	}
		382
248		383
249	=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)	384	=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
250		385
251	=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)	386	=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
252		387
253	Reads or writes C<length> bytes from the specified C<fh> and C<offset>	388	Reads or writes C<$length> bytes from the specified C<$fh> and C<$offset>
254	into the scalar given by C<data> and offset C<dataoffset> and calls the	389	into the scalar given by C<$data> and offset C<$dataoffset> and calls the
255	callback without the actual number of bytes read (or -1 on error, just	390	callback without the actual number of bytes read (or -1 on error, just
256	like the syscall).	391	like the syscall).
257		392
		393	If C<$offset> is undefined, then the current file descriptor offset will
		394	be used (and updated), otherwise the file descriptor offset will not be
		395	changed by these calls.
		396
		397	If C<$length> is undefined in C<aio_write>, use the remaining length of C<$data>.
		398
		399	If C<$dataoffset> is less than zero, it will be counted from the end of
		400	C<$data>.
		401
258	The C<$data> scalar I<MUST NOT> be modified in any way while the request	402	The C<$data> scalar I<MUST NOT> be modified in any way while the request
259	is outstanding. Modifying it can result in segfaults or WW3 (if the	403	is outstanding. Modifying it can result in segfaults or World War III (if
260	necessary/optional hardware is installed).	404	the necessary/optional hardware is installed).
261		405
262	Example: Read 15 bytes at offset 7 into scalar C<$buffer>, starting at	406	Example: Read 15 bytes at offset 7 into scalar C<$buffer>, starting at
263	offset C<0> within the scalar:	407	offset C<0> within the scalar:
264		408
265	aio_read $fh, 7, 15, $buffer, 0, sub {	409	aio_read $fh, 7, 15, $buffer, 0, sub {
266	$_[0] > 0 or die "read error: $!";	410	$_[0] > 0 or die "read error: $!";
267	print "read $_[0] bytes: <$buffer>\n";	411	print "read $_[0] bytes: <$buffer>\n";
268	};	412	};
		413
269		414
270	=item aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval)	415	=item aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval)
271		416
272	Tries to copy C<$length> bytes from C<$in_fh> to C<$out_fh>. It starts	417	Tries to copy C<$length> bytes from C<$in_fh> to C<$out_fh>. It starts
273	reading at byte offset C<$in_offset>, and starts writing at the current	418	reading at byte offset C<$in_offset>, and starts writing at the current
…		…
287	C<$in_fh> than are written, and there is no way to find out how many	432	C<$in_fh> than are written, and there is no way to find out how many
288	bytes have been read from C<aio_sendfile> alone, as C<aio_sendfile> only	433	bytes have been read from C<aio_sendfile> alone, as C<aio_sendfile> only
289	provides the number of bytes written to C<$out_fh>. Only if the result	434	provides the number of bytes written to C<$out_fh>. Only if the result
290	value equals C<$length> one can assume that C<$length> bytes have been	435	value equals C<$length> one can assume that C<$length> bytes have been
291	read.	436	read.
		437
292		438
293	=item aio_readahead $fh,$offset,$length, $callback->($retval)	439	=item aio_readahead $fh,$offset,$length, $callback->($retval)
294		440
295	C<aio_readahead> populates the page cache with data from a file so that	441	C<aio_readahead> populates the page cache with data from a file so that
296	subsequent reads from that file will not block on disk I/O. The C<$offset>	442	subsequent reads from that file will not block on disk I/O. The C<$offset>
…		…
302	file. The current file offset of the file is left unchanged.	448	file. The current file offset of the file is left unchanged.
303		449
304	If that syscall doesn't exist (likely if your OS isn't Linux) it will be	450	If that syscall doesn't exist (likely if your OS isn't Linux) it will be
305	emulated by simply reading the data, which would have a similar effect.	451	emulated by simply reading the data, which would have a similar effect.
306		452
		453
307	=item aio_stat $fh_or_path, $callback->($status)	454	=item aio_stat $fh_or_path, $callback->($status)
308		455
309	=item aio_lstat $fh, $callback->($status)	456	=item aio_lstat $fh, $callback->($status)
310		457
311	Works like perl's C<stat> or C<lstat> in void context. The callback will	458	Works like perl's C<stat> or C<lstat> in void context. The callback will
…		…
324	aio_stat "/etc/passwd", sub {	471	aio_stat "/etc/passwd", sub {
325	$_[0] and die "stat failed: $!";	472	$_[0] and die "stat failed: $!";
326	print "size is ", -s _, "\n";	473	print "size is ", -s _, "\n";
327	};	474	};
328		475
		476
		477	=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
		478
		479	Works like perl's C<utime> function (including the special case of $atime
		480	and $mtime being undef). Fractional times are supported if the underlying
		481	syscalls support them.
		482
		483	When called with a pathname, uses utimes(2) if available, otherwise
		484	utime(2). If called on a file descriptor, uses futimes(2) if available,
		485	otherwise returns ENOSYS, so this is not portable.
		486
		487	Examples:
		488
		489	# set atime and mtime to current time (basically touch(1)):
		490	aio_utime "path", undef, undef;
		491	# set atime to current time and mtime to beginning of the epoch:
		492	aio_utime "path", time, undef; # undef==0
		493
		494
		495	=item aio_chown $fh_or_path, $uid, $gid, $callback->($status)
		496
		497	Works like perl's C<chown> function, except that C<undef> for either $uid
		498	or $gid is being interpreted as "do not change" (but -1 can also be used).
		499
		500	Examples:
		501
		502	# same as "chown root path" in the shell:
		503	aio_chown "path", 0, -1;
		504	# same as above:
		505	aio_chown "path", 0, undef;
		506
		507
		508	=item aio_truncate $fh_or_path, $offset, $callback->($status)
		509
		510	Works like truncate(2) or ftruncate(2).
		511
		512
		513	=item aio_chmod $fh_or_path, $mode, $callback->($status)
		514
		515	Works like perl's C<chmod> function.
		516
		517
329	=item aio_unlink $pathname, $callback->($status)	518	=item aio_unlink $pathname, $callback->($status)
330		519
331	Asynchronously unlink (delete) a file and call the callback with the	520	Asynchronously unlink (delete) a file and call the callback with the
332	result code.	521	result code.
333		522
		523
334	=item aio_mknod $path, $mode, $dev, $callback->($status)	524	=item aio_mknod $path, $mode, $dev, $callback->($status)
335		525
		526	[EXPERIMENTAL]
		527
336	Asynchronously create a device node (or fifo). See mknod(2): the only	528	Asynchronously create a device node (or fifo). See mknod(2).
337	portable value for C<$mode> is C<S_IFIFO> ored with permissions, and C<0>	529
338	for C<$dev>.	530	The only (POSIX-) portable way of calling this function is:
		531
		532	aio_mknod $path, IO::AIO::S_IFIFO \| $mode, 0, sub { ...
		533
339		534
340	=item aio_link $srcpath, $dstpath, $callback->($status)	535	=item aio_link $srcpath, $dstpath, $callback->($status)
341		536
342	Asynchronously create a new link to the existing object at C<$srcpath> at	537	Asynchronously create a new link to the existing object at C<$srcpath> at
343	the path C<$dstpath> and call the callback with the result code.	538	the path C<$dstpath> and call the callback with the result code.
344		539
		540
345	=item aio_symlink $srcpath, $dstpath, $callback->($status)	541	=item aio_symlink $srcpath, $dstpath, $callback->($status)
346		542
347	Asynchronously create a new symbolic link to the existing object at C<$srcpath> at	543	Asynchronously create a new symbolic link to the existing object at C<$srcpath> at
348	the path C<$dstpath> and call the callback with the result code.	544	the path C<$dstpath> and call the callback with the result code.
349		545
		546
		547	=item aio_readlink $path, $callback->($link)
		548
		549	Asynchronously read the symlink specified by C<$path> and pass it to
		550	the callback. If an error occurs, nothing or undef gets passed to the
		551	callback.
		552
		553
350	=item aio_rename $srcpath, $dstpath, $callback->($status)	554	=item aio_rename $srcpath, $dstpath, $callback->($status)
351		555
352	Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as	556	Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as
353	rename(2) and call the callback with the result code.	557	rename(2) and call the callback with the result code.
354		558
		559
		560	=item aio_mkdir $pathname, $mode, $callback->($status)
		561
		562	Asynchronously mkdir (create) a directory and call the callback with
		563	the result code. C<$mode> will be modified by the umask at the time the
		564	request is executed, so do not change your umask.
		565
		566
355	=item aio_rmdir $pathname, $callback->($status)	567	=item aio_rmdir $pathname, $callback->($status)
356		568
357	Asynchronously rmdir (delete) a directory and call the callback with the	569	Asynchronously rmdir (delete) a directory and call the callback with the
358	result code.	570	result code.
		571
359		572
360	=item aio_readdir $pathname, $callback->($entries)	573	=item aio_readdir $pathname, $callback->($entries)
361		574
362	Unlike the POSIX call of the same name, C<aio_readdir> reads an entire	575	Unlike the POSIX call of the same name, C<aio_readdir> reads an entire
363	directory (i.e. opendir + readdir + closedir). The entries will not be	576	directory (i.e. opendir + readdir + closedir). The entries will not be
364	sorted, and will B<NOT> include the C<.> and C<..> entries.	577	sorted, and will B<NOT> include the C<.> and C<..> entries.
365		578
366	The callback a single argument which is either C<undef> or an array-ref	579	The callback a single argument which is either C<undef> or an array-ref
367	with the filenames.	580	with the filenames.
		581
		582
		583	=item aio_load $path, $data, $callback->($status)
		584
		585	This is a composite request that tries to fully load the given file into
		586	memory. Status is the same as with aio_read.
		587
		588	=cut
		589
		590	sub aio_load($$;$) {
		591	aio_block {
		592	my ($path, undef, $cb) = @_;
		593	my $data = \$_[1];
		594
		595	my $pri = aioreq_pri;
		596	my $grp = aio_group $cb;
		597
		598	aioreq_pri $pri;
		599	add $grp aio_open $path, O_RDONLY, 0, sub {
		600	my $fh = shift
		601	or return $grp->result (-1);
		602
		603	aioreq_pri $pri;
		604	add $grp aio_read $fh, 0, (-s $fh), $$data, 0, sub {
		605	$grp->result ($_[0]);
		606	};
		607	};
		608
		609	$grp
		610	}
		611	}
368		612
369	=item aio_copy $srcpath, $dstpath, $callback->($status)	613	=item aio_copy $srcpath, $dstpath, $callback->($status)
370		614
371	Try to copy the I<file> (directories not supported as either source or	615	Try to copy the I<file> (directories not supported as either source or
372	destination) from C<$srcpath> to C<$dstpath> and call the callback with	616	destination) from C<$srcpath> to C<$dstpath> and call the callback with
…		…
382	errors are being ignored.	626	errors are being ignored.
383		627
384	=cut	628	=cut
385		629
386	sub aio_copy($$;$) {	630	sub aio_copy($$;$) {
		631	aio_block {
387	my ($src, $dst, $cb) = @_;	632	my ($src, $dst, $cb) = @_;
388		633
389	my $pri = aioreq_pri;	634	my $pri = aioreq_pri;
390	my $grp = aio_group $cb;	635	my $grp = aio_group $cb;
391		636
392	aioreq_pri $pri;	637	aioreq_pri $pri;
393	add $grp aio_open $src, O_RDONLY, 0, sub {	638	add $grp aio_open $src, O_RDONLY, 0, sub {
394	if (my $src_fh = $_[0]) {	639	if (my $src_fh = $_[0]) {
395	my @stat = stat $src_fh;	640	my @stat = stat $src_fh;
396		641
397	aioreq_pri $pri;	642	aioreq_pri $pri;
398	add $grp aio_open $dst, O_CREAT \| O_WRONLY \| O_TRUNC, 0200, sub {	643	add $grp aio_open $dst, O_CREAT \| O_WRONLY \| O_TRUNC, 0200, sub {
399	if (my $dst_fh = $_[0]) {	644	if (my $dst_fh = $_[0]) {
400	aioreq_pri $pri;	645	aioreq_pri $pri;
401	add $grp aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub {	646	add $grp aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub {
402	if ($_[0] == $stat[7]) {	647	if ($_[0] == $stat[7]) {
403	$grp->result (0);	648	$grp->result (0);
404	close $src_fh;	649	close $src_fh;
405		650
406	# those should not normally block. should. should.	651	# those should not normally block. should. should.
407	utime $stat[8], $stat[9], $dst;	652	utime $stat[8], $stat[9], $dst;
408	chmod $stat[2] & 07777, $dst_fh;	653	chmod $stat[2] & 07777, $dst_fh;
409	chown $stat[4], $stat[5], $dst_fh;	654	chown $stat[4], $stat[5], $dst_fh;
410	close $dst_fh;	655	close $dst_fh;
411	} else {	656	} else {
412	$grp->result (-1);	657	$grp->result (-1);
413	close $src_fh;	658	close $src_fh;
414	close $dst_fh;	659	close $dst_fh;
415		660
416	aioreq $pri;	661	aioreq $pri;
417	add $grp aio_unlink $dst;	662	add $grp aio_unlink $dst;
		663	}
418	}	664	};
		665	} else {
		666	$grp->result (-1);
419	};	667	}
420	} else {
421	$grp->result (-1);
422	}	668	},
		669
		670	} else {
		671	$grp->result (-1);
423	},	672	}
424
425	} else {
426	$grp->result (-1);
427	}	673	};
		674
		675	$grp
428	};	676	}
429
430	$grp
431	}	677	}
432		678
433	=item aio_move $srcpath, $dstpath, $callback->($status)	679	=item aio_move $srcpath, $dstpath, $callback->($status)
434		680
435	Try to move the I<file> (directories not supported as either source or	681	Try to move the I<file> (directories not supported as either source or
…		…
441	that is successful, unlinking the C<$srcpath>.	687	that is successful, unlinking the C<$srcpath>.
442		688
443	=cut	689	=cut
444		690
445	sub aio_move($$;$) {	691	sub aio_move($$;$) {
		692	aio_block {
446	my ($src, $dst, $cb) = @_;	693	my ($src, $dst, $cb) = @_;
447		694
448	my $pri = aioreq_pri;	695	my $pri = aioreq_pri;
449	my $grp = aio_group $cb;	696	my $grp = aio_group $cb;
450		697
451	aioreq_pri $pri;	698	aioreq_pri $pri;
452	add $grp aio_rename $src, $dst, sub {	699	add $grp aio_rename $src, $dst, sub {
453	if ($_[0] && $! == EXDEV) {	700	if ($_[0] && $! == EXDEV) {
454	aioreq_pri $pri;	701	aioreq_pri $pri;
455	add $grp aio_copy $src, $dst, sub {	702	add $grp aio_copy $src, $dst, sub {
		703	$grp->result ($_[0]);
		704
		705	if (!$_[0]) {
		706	aioreq_pri $pri;
		707	add $grp aio_unlink $src;
		708	}
		709	};
		710	} else {
456	$grp->result ($_[0]);	711	$grp->result ($_[0]);
457
458	if (!$_[0]) {
459	aioreq_pri $pri;
460	add $grp aio_unlink $src;
461	}
462	};	712	}
463	} else {
464	$grp->result ($_[0]);
465	}	713	};
		714
		715	$grp
466	};	716	}
467
468	$grp
469	}	717	}
470		718
471	=item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs)	719	=item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs)
472		720
473	Scans a directory (similar to C<aio_readdir>) but additionally tries to	721	Scans a directory (similar to C<aio_readdir>) but additionally tries to
…		…
520	as those tend to return 0 or 1 as link counts, which disables the	768	as those tend to return 0 or 1 as link counts, which disables the
521	directory counting heuristic.	769	directory counting heuristic.
522		770
523	=cut	771	=cut
524		772
525	sub aio_scandir($$$) {	773	sub aio_scandir($$;$) {
		774	aio_block {
526	my ($path, $maxreq, $cb) = @_;	775	my ($path, $maxreq, $cb) = @_;
527		776
528	my $pri = aioreq_pri;	777	my $pri = aioreq_pri;
529		778
530	my $grp = aio_group $cb;	779	my $grp = aio_group $cb;
531		780
532	$maxreq = 4 if $maxreq <= 0;	781	$maxreq = 4 if $maxreq <= 0;
533		782
534	# stat once	783	# stat once
535	aioreq_pri $pri;
536	add $grp aio_stat $path, sub {
537	return $grp->result () if $_[0];
538	my $now = time;
539	my $hash1 = join ":", (stat _)[0,1,3,7,9];
540
541	# read the directory entries
542	aioreq_pri $pri;	784	aioreq_pri $pri;
543	add $grp aio_readdir $path, sub {	785	add $grp aio_stat $path, sub {
544	my $entries = shift
545	or return $grp->result ();	786	return $grp->result () if $_[0];
		787	my $now = time;
		788	my $hash1 = join ":", (stat _)[0,1,3,7,9];
546		789
547	# stat the dir another time	790	# read the directory entries
548	aioreq_pri $pri;	791	aioreq_pri $pri;
		792	add $grp aio_readdir $path, sub {
		793	my $entries = shift
		794	or return $grp->result ();
		795
		796	# stat the dir another time
		797	aioreq_pri $pri;
549	add $grp aio_stat $path, sub {	798	add $grp aio_stat $path, sub {
550	my $hash2 = join ":", (stat _)[0,1,3,7,9];	799	my $hash2 = join ":", (stat _)[0,1,3,7,9];
551		800
552	my $ndirs;	801	my $ndirs;
553		802
554	# take the slow route if anything looks fishy	803	# take the slow route if anything looks fishy
555	if ($hash1 ne $hash2 or (stat _)[9] == $now) {	804	if ($hash1 ne $hash2 or (stat _)[9] == $now) {
556	$ndirs = -1;	805	$ndirs = -1;
557	} else {	806	} else {
558	# if nlink == 2, we are finished	807	# if nlink == 2, we are finished
559	# on non-posix-fs's, we rely on nlink < 2	808	# on non-posix-fs's, we rely on nlink < 2
560	$ndirs = (stat _)[3] - 2	809	$ndirs = (stat _)[3] - 2
561	or return $grp->result ([], $entries);	810	or return $grp->result ([], $entries);
562	}	811	}
563		812
564	# sort into likely dirs and likely nondirs	813	# sort into likely dirs and likely nondirs
565	# dirs == files without ".", short entries first	814	# dirs == files without ".", short entries first
566	$entries = [map $_->[0],	815	$entries = [map $_->[0],
567	sort { $b->[1] cmp $a->[1] }	816	sort { $b->[1] cmp $a->[1] }
568	map [$_, sprintf "%s%04d", (/.\./ ? "1" : "0"), length],	817	map [$_, sprintf "%s%04d", (/.\./ ? "1" : "0"), length],
569	@$entries];	818	@$entries];
570		819
571	my (@dirs, @nondirs);	820	my (@dirs, @nondirs);
572		821
573	my $statgrp = add $grp aio_group sub {	822	my $statgrp = add $grp aio_group sub {
574	$grp->result (\@dirs, \@nondirs);	823	$grp->result (\@dirs, \@nondirs);
575	};	824	};
576		825
577	limit $statgrp $maxreq;	826	limit $statgrp $maxreq;
578	feed $statgrp sub {	827	feed $statgrp sub {
579	return unless @$entries;	828	return unless @$entries;
580	my $entry = pop @$entries;	829	my $entry = pop @$entries;
581		830
582	aioreq_pri $pri;	831	aioreq_pri $pri;
583	add $statgrp aio_stat "$path/$entry/.", sub {	832	add $statgrp aio_stat "$path/$entry/.", sub {
584	if ($_[0] < 0) {	833	if ($_[0] < 0) {
585	push @nondirs, $entry;	834	push @nondirs, $entry;
586	} else {	835	} else {
587	# need to check for real directory	836	# need to check for real directory
588	aioreq_pri $pri;	837	aioreq_pri $pri;
589	add $statgrp aio_lstat "$path/$entry", sub {	838	add $statgrp aio_lstat "$path/$entry", sub {
590	if (-d _) {	839	if (-d _) {
591	push @dirs, $entry;	840	push @dirs, $entry;
592		841
593	unless (--$ndirs) {	842	unless (--$ndirs) {
594	push @nondirs, @$entries;	843	push @nondirs, @$entries;
595	feed $statgrp;	844	feed $statgrp;
		845	}
		846	} else {
		847	push @nondirs, $entry;
596	}	848	}
597	} else {
598	push @nondirs, $entry;
599	}	849	}
600	}	850	}
601	}	851	};
602	};	852	};
603	};	853	};
604	};	854	};
605	};	855	};
		856
		857	$grp
606	};	858	}
607
608	$grp
609	}	859	}
		860
		861	=item aio_rmtree $path, $callback->($status)
		862
		863	Delete a directory tree starting (and including) C<$path>, return the
		864	status of the final C<rmdir> only. This is a composite request that
		865	uses C<aio_scandir> to recurse into and rmdir directories, and unlink
		866	everything else.
		867
		868	=cut
		869
		870	sub aio_rmtree;
		871	sub aio_rmtree($;$) {
		872	aio_block {
		873	my ($path, $cb) = @_;
		874
		875	my $pri = aioreq_pri;
		876	my $grp = aio_group $cb;
		877
		878	aioreq_pri $pri;
		879	add $grp aio_scandir $path, 0, sub {
		880	my ($dirs, $nondirs) = @_;
		881
		882	my $dirgrp = aio_group sub {
		883	add $grp aio_rmdir $path, sub {
		884	$grp->result ($_[0]);
		885	};
		886	};
		887
		888	(aioreq_pri $pri), add $dirgrp aio_rmtree "$path/$_" for @$dirs;
		889	(aioreq_pri $pri), add $dirgrp aio_unlink "$path/$_" for @$nondirs;
		890
		891	add $grp $dirgrp;
		892	};
		893
		894	$grp
		895	}
		896	}
		897
		898	=item aio_sync $callback->($status)
		899
		900	Asynchronously call sync and call the callback when finished.
610		901
611	=item aio_fsync $fh, $callback->($status)	902	=item aio_fsync $fh, $callback->($status)
612		903
613	Asynchronously call fsync on the given filehandle and call the callback	904	Asynchronously call fsync on the given filehandle and call the callback
614	with the fsync result code.	905	with the fsync result code.
…		…
827		1118
828	=back	1119	=back
829		1120
830	=head2 SUPPORT FUNCTIONS	1121	=head2 SUPPORT FUNCTIONS
831		1122
		1123	=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION
		1124
832	=over 4	1125	=over 4
833		1126
834	=item $fileno = IO::AIO::poll_fileno	1127	=item $fileno = IO::AIO::poll_fileno
835		1128
836	Return the I<request result pipe file descriptor>. This filehandle must be	1129	Return the I<request result pipe file descriptor>. This filehandle must be
…		…
840		1133
841	See C<poll_cb> for an example.	1134	See C<poll_cb> for an example.
842		1135
843	=item IO::AIO::poll_cb	1136	=item IO::AIO::poll_cb
844		1137
845	Process all outstanding events on the result pipe. You have to call this	1138	Process some outstanding events on the result pipe. You have to call this
846	regularly. Returns the number of events processed. Returns immediately	1139	regularly. Returns the number of events processed. Returns immediately
847	when no events are outstanding.	1140	when no events are outstanding. The amount of events processed depends on
		1141	the settings of C<IO::AIO::max_poll_req> and C<IO::AIO::max_poll_time>.
848		1142
849	If not all requests were processed for whatever reason, the filehandle	1143	If not all requests were processed for whatever reason, the filehandle
850	will still be ready when C<poll_cb> returns.	1144	will still be ready when C<poll_cb> returns.
851		1145
852	Example: Install an Event watcher that automatically calls	1146	Example: Install an Event watcher that automatically calls
…		…
854		1148
855	Event->io (fd => IO::AIO::poll_fileno,	1149	Event->io (fd => IO::AIO::poll_fileno,
856	poll => 'r', async => 1,	1150	poll => 'r', async => 1,
857	cb => \&IO::AIO::poll_cb);	1151	cb => \&IO::AIO::poll_cb);
858		1152
859	=item IO::AIO::poll_some $max_requests	1153	=item IO::AIO::max_poll_reqs $nreqs
860		1154
861	Similar to C<poll_cb>, but only processes up to C<$max_requests> requests	1155	=item IO::AIO::max_poll_time $seconds
862	at a time.
863		1156
864	Useful if you want to ensure some level of interactiveness when perl is	1157	These set the maximum number of requests (default C<0>, meaning infinity)
865	not fast enough to process all requests in time.	1158	that are being processed by C<IO::AIO::poll_cb> in one call, respectively
		1159	the maximum amount of time (default C<0>, meaning infinity) spent in
		1160	C<IO::AIO::poll_cb> to process requests (more correctly the mininum amount
		1161	of time C<poll_cb> is allowed to use).
		1162
		1163	Setting C<max_poll_time> to a non-zero value creates an overhead of one
		1164	syscall per request processed, which is not normally a problem unless your
		1165	callbacks are really really fast or your OS is really really slow (I am
		1166	not mentioning Solaris here). Using C<max_poll_reqs> incurs no overhead.
		1167
		1168	Setting these is useful if you want to ensure some level of
		1169	interactiveness when perl is not fast enough to process all requests in
		1170	time.
		1171
		1172	For interactive programs, values such as C<0.01> to C<0.1> should be fine.
866		1173
867	Example: Install an Event watcher that automatically calls	1174	Example: Install an Event watcher that automatically calls
868	IO::AIO::poll_some with low priority, to ensure that other parts of the	1175	IO::AIO::poll_cb with low priority, to ensure that other parts of the
869	program get the CPU sometimes even under high AIO load.	1176	program get the CPU sometimes even under high AIO load.
870		1177
		1178	# try not to spend much more than 0.1s in poll_cb
		1179	IO::AIO::max_poll_time 0.1;
		1180
		1181	# use a low priority so other tasks have priority
871	Event->io (fd => IO::AIO::poll_fileno,	1182	Event->io (fd => IO::AIO::poll_fileno,
872	poll => 'r', nice => 1,	1183	poll => 'r', nice => 1,
873	cb => sub { IO::AIO::poll_some 256 });	1184	cb => &IO::AIO::poll_cb);
874		1185
875	=item IO::AIO::poll_wait	1186	=item IO::AIO::poll_wait
876		1187
		1188	If there are any outstanding requests and none of them in the result
877	Wait till the result filehandle becomes ready for reading (simply does a	1189	phase, wait till the result filehandle becomes ready for reading (simply
878	C<select> on the filehandle. This is useful if you want to synchronously wait	1190	does a C<select> on the filehandle. This is useful if you want to
879	for some requests to finish).	1191	synchronously wait for some requests to finish).
880		1192
881	See C<nreqs> for an example.	1193	See C<nreqs> for an example.
882		1194
		1195	=item IO::AIO::poll
		1196
		1197	Waits until some requests have been handled.
		1198
		1199	Returns the number of requests processed, but is otherwise strictly
		1200	equivalent to:
		1201
		1202	IO::AIO::poll_wait, IO::AIO::poll_cb
		1203
883	=item IO::AIO::nreqs	1204	=item IO::AIO::flush
884		1205
885	Returns the number of requests currently in the ready, execute or pending	1206	Wait till all outstanding AIO requests have been handled.
886	states (i.e. for which their callback has not been invoked yet).
887		1207
888	Example: wait till there are no outstanding requests anymore:	1208	Strictly equivalent to:
889		1209
890	IO::AIO::poll_wait, IO::AIO::poll_cb	1210	IO::AIO::poll_wait, IO::AIO::poll_cb
891	while IO::AIO::nreqs;	1211	while IO::AIO::nreqs;
892		1212
893	=item IO::AIO::nready	1213	=back
894		1214
895	Returns the number of requests currently in the ready state (not yet	1215	=head3 CONTROLLING THE NUMBER OF THREADS
896	executed).
897		1216
898	=item IO::AIO::npending	1217	=over
899
900	Returns the number of requests currently in the pending state (executed,
901	but not yet processed by poll_cb).
902
903	=item IO::AIO::flush
904
905	Wait till all outstanding AIO requests have been handled.
906
907	Strictly equivalent to:
908
909	IO::AIO::poll_wait, IO::AIO::poll_cb
910	while IO::AIO::nreqs;
911
912	=item IO::AIO::poll
913
914	Waits until some requests have been handled.
915
916	Strictly equivalent to:
917
918	IO::AIO::poll_wait, IO::AIO::poll_cb
919	if IO::AIO::nreqs;
920		1218
921	=item IO::AIO::min_parallel $nthreads	1219	=item IO::AIO::min_parallel $nthreads
922		1220
923	Set the minimum number of AIO threads to C<$nthreads>. The current	1221	Set the minimum number of AIO threads to C<$nthreads>. The current
924	default is C<8>, which means eight asynchronous operations can execute	1222	default is C<8>, which means eight asynchronous operations can execute
925	concurrently at any one time (the number of outstanding requests,	1223	concurrently at any one time (the number of outstanding requests,
926	however, is unlimited).	1224	however, is unlimited).
927		1225
928	IO::AIO starts threads only on demand, when an AIO request is queued and	1226	IO::AIO starts threads only on demand, when an AIO request is queued and
929	no free thread exists.	1227	no free thread exists. Please note that queueing up a hundred requests can
		1228	create demand for a hundred threads, even if it turns out that everything
		1229	is in the cache and could have been processed faster by a single thread.
930		1230
931	It is recommended to keep the number of threads relatively low, as some	1231	It is recommended to keep the number of threads relatively low, as some
932	Linux kernel versions will scale negatively with the number of threads	1232	Linux kernel versions will scale negatively with the number of threads
933	(higher parallelity => MUCH higher latency). With current Linux 2.6	1233	(higher parallelity => MUCH higher latency). With current Linux 2.6
934	versions, 4-32 threads should be fine.	1234	versions, 4-32 threads should be fine.
…		…
948	This module automatically runs C<max_parallel 0> at program end, to ensure	1248	This module automatically runs C<max_parallel 0> at program end, to ensure
949	that all threads are killed and that there are no outstanding requests.	1249	that all threads are killed and that there are no outstanding requests.
950		1250
951	Under normal circumstances you don't need to call this function.	1251	Under normal circumstances you don't need to call this function.
952		1252
		1253	=item IO::AIO::max_idle $nthreads
		1254
		1255	Limit the number of threads (default: 4) that are allowed to idle (i.e.,
		1256	threads that did not get a request to process within 10 seconds). That
		1257	means if a thread becomes idle while C<$nthreads> other threads are also
		1258	idle, it will free its resources and exit.
		1259
		1260	This is useful when you allow a large number of threads (e.g. 100 or 1000)
		1261	to allow for extremely high load situations, but want to free resources
		1262	under normal circumstances (1000 threads can easily consume 30MB of RAM).
		1263
		1264	The default is probably ok in most situations, especially if thread
		1265	creation is fast. If thread creation is very slow on your system you might
		1266	want to use larger values.
		1267
953	=item $oldmaxreqs = IO::AIO::max_outstanding $maxreqs	1268	=item $oldmaxreqs = IO::AIO::max_outstanding $maxreqs
954		1269
955	This is a very bad function to use in interactive programs because it	1270	This is a very bad function to use in interactive programs because it
956	blocks, and a bad way to reduce concurrency because it is inexact: Better	1271	blocks, and a bad way to reduce concurrency because it is inexact: Better
957	use an C<aio_group> together with a feed callback.	1272	use an C<aio_group> together with a feed callback.
958		1273
959	Sets the maximum number of outstanding requests to C<$nreqs>. If you	1274	Sets the maximum number of outstanding requests to C<$nreqs>. If you
960	to queue up more than this number of requests, the next call to the	1275	do queue up more than this number of requests, the next call to the
961	C<poll_cb> (and C<poll_some> and other functions calling C<poll_cb>)	1276	C<poll_cb> (and C<poll_some> and other functions calling C<poll_cb>)
962	function will block until the limit is no longer exceeded.	1277	function will block until the limit is no longer exceeded.
963		1278
964	The default value is very large, so there is no practical limit on the	1279	The default value is very large, so there is no practical limit on the
965	number of outstanding requests.	1280	number of outstanding requests.
…		…
968	C<max_oustsanding> is mainly useful in simple scripts (with low values) or	1283	C<max_oustsanding> is mainly useful in simple scripts (with low values) or
969	as a stop gap to shield against fatal memory overflow (with large values).	1284	as a stop gap to shield against fatal memory overflow (with large values).
970		1285
971	=back	1286	=back
972		1287
		1288	=head3 STATISTICAL INFORMATION
		1289
		1290	=over
		1291
		1292	=item IO::AIO::nreqs
		1293
		1294	Returns the number of requests currently in the ready, execute or pending
		1295	states (i.e. for which their callback has not been invoked yet).
		1296
		1297	Example: wait till there are no outstanding requests anymore:
		1298
		1299	IO::AIO::poll_wait, IO::AIO::poll_cb
		1300	while IO::AIO::nreqs;
		1301
		1302	=item IO::AIO::nready
		1303
		1304	Returns the number of requests currently in the ready state (not yet
		1305	executed).
		1306
		1307	=item IO::AIO::npending
		1308
		1309	Returns the number of requests currently in the pending state (executed,
		1310	but not yet processed by poll_cb).
		1311
		1312	=back
		1313
973	=cut	1314	=cut
974		1315
975	# support function to convert a fd into a perl filehandle
976	sub _fd2fh {
977	return undef if $_[0] < 0;
978
979	# try to generate nice filehandles
980	my $sym = "IO::AIO::fd#$_[0]";
981	local *$sym;
982
983	open *$sym, "+<&=$_[0]" # usually works under any unix
984	or open *$sym, "<&=$_[0]" # cygwin needs this
985	or open *$sym, ">&=$_[0]" # or this
986	or return undef;
987
988	*$sym
989	}
990
991	min_parallel 8;	1316	min_parallel 8;
992		1317
993	END {	1318	END { flush }
994	flush;
995	};
996		1319
997	1;	1320	1;
998		1321
999	=head2 FORK BEHAVIOUR	1322	=head2 FORK BEHAVIOUR
1000		1323
…		…
1020	bytes of memory. In addition, stat requests need a stat buffer (possibly	1343	bytes of memory. In addition, stat requests need a stat buffer (possibly
1021	a few hundred bytes), readdir requires a result buffer and so on. Perl	1344	a few hundred bytes), readdir requires a result buffer and so on. Perl
1022	scalars and other data passed into aio requests will also be locked and	1345	scalars and other data passed into aio requests will also be locked and
1023	will consume memory till the request has entered the done state.	1346	will consume memory till the request has entered the done state.
1024		1347
1025	This is now awfully much, so queuing lots of requests is not usually a	1348	This is not awfully much, so queuing lots of requests is not usually a
1026	problem.	1349	problem.
1027		1350
1028	Per-thread usage:	1351	Per-thread usage:
1029		1352
1030	In the execution phase, some aio requests require more memory for	1353	In the execution phase, some aio requests require more memory for

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Comparing IO-AIO/AIO.pm (file contents): Revision 1.82 by root, Fri Oct 27 20:10:06 2006 UTC vs. Revision 1.119 by root, Sun Dec 2 20:54:33 2007 UTC

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Comparing IO-AIO/AIO.pm (file contents):
Revision 1.82 by root, Fri Oct 27 20:10:06 2006 UTC vs.
Revision 1.119 by root, Sun Dec 2 20:54:33 2007 UTC