[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 1.125 by root, Sat May 10 22:47:34 2008 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
		31	# AnyEvent integration (EV, Event, Glib, Tk, POE, urxvt, pureperl...)
		32	use AnyEvent::AIO;
		33
30	# AnyEvent integration	34	# EV integration
31	open my $fh, "<&=" . IO::AIO::poll_fileno or die "$!";	35	my $w = EV::io IO::AIO::poll_fileno, EV::READ, \&IO::AIO::poll_cb;
32	my $w = AnyEvent->io (fh => $fh, poll => 'r', cb => sub { IO::AIO::poll_cb });
33		36
34	# Event integration	37	# Event integration
35	Event->io (fd => IO::AIO::poll_fileno,	38	Event->io (fd => IO::AIO::poll_fileno,
36	poll => 'r',	39	poll => 'r',
37	cb => \&IO::AIO::poll_cb);	40	cb => \&IO::AIO::poll_cb);
…		…
50		53
51	=head1 DESCRIPTION	54	=head1 DESCRIPTION
52		55
53	This module implements asynchronous I/O using whatever means your	56	This module implements asynchronous I/O using whatever means your
54	operating system supports.	57	operating system supports.
		58
		59	Asynchronous means that operations that can normally block your program
		60	(e.g. reading from disk) will be done asynchronously: the operation
		61	will still block, but you can do something else in the meantime. This
		62	is extremely useful for programs that need to stay interactive even
		63	when doing heavy I/O (GUI programs, high performance network servers
		64	etc.), but can also be used to easily do operations in parallel that are
		65	normally done sequentially, e.g. stat'ing many files, which is much faster
		66	on a RAID volume or over NFS when you do a number of stat operations
		67	concurrently.
		68
		69	While most of this works on all types of file descriptors (for
		70	example sockets), using these functions on file descriptors that
		71	support nonblocking operation (again, sockets, pipes etc.) is very
		72	inefficient. Use an event loop for that (such as the L<Event\|Event>
		73	module): IO::AIO will naturally fit into such an event loop itself.
55		74
56	In this version, a number of threads are started that execute your	75	In this version, a number of threads are started that execute your
57	requests and signal their completion. You don't need thread support	76	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	77	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	78	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	79	functions available on many operating systems. However, they are often
61	not well-supported or restricted (Linux doesn't allow them on normal	80	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	81	files currently, for example), and they would only support aio_read and
63	aio_write, so the remaining functionality would have to be implemented	82	aio_write, so the remaining functionality would have to be implemented
64	using threads anyway.	83	using threads anyway.
65		84
66	Although the module will work with in the presence of other (Perl-)	85	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	86	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	87	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.	88	call C<poll_cb> (or other C<aio_> functions) recursively.
		89
		90	=head2 EXAMPLE
		91
		92	This is a simple example that uses the Event module and loads
		93	F</etc/passwd> asynchronously:
		94
		95	use Fcntl;
		96	use Event;
		97	use IO::AIO;
		98
		99	# register the IO::AIO callback with Event
		100	Event->io (fd => IO::AIO::poll_fileno,
		101	poll => 'r',
		102	cb => \&IO::AIO::poll_cb);
		103
		104	# queue the request to open /etc/passwd
		105	aio_open "/etc/passwd", O_RDONLY, 0, sub {
		106	my $fh = shift
		107	or die "error while opening: $!";
		108
		109	# stat'ing filehandles is generally non-blocking
		110	my $size = -s $fh;
		111
		112	# queue a request to read the file
		113	my $contents;
		114	aio_read $fh, 0, $size, $contents, 0, sub {
		115	$_[0] == $size
		116	or die "short read: $!";
		117
		118	close $fh;
		119
		120	# file contents now in $contents
		121	print $contents;
		122
		123	# exit event loop and program
		124	Event::unloop;
		125	};
		126	};
		127
		128	# possibly queue up other requests, or open GUI windows,
		129	# check for sockets etc. etc.
		130
		131	# process events as long as there are some:
		132	Event::loop;
70		133
71	=head1 REQUEST ANATOMY AND LIFETIME	134	=head1 REQUEST ANATOMY AND LIFETIME
72		135
73	Every C<aio_*> function creates a request. which is a C data structure not	136	Every C<aio_*> function creates a request. which is a C data structure not
74	directly visible to Perl.	137	directly visible to Perl.
…		…
116	Request has reached the end of its lifetime and holds no resources anymore	179	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	180	(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	181	aio request is severed and calling its methods will either do nothing or
119	result in a runtime error).	182	result in a runtime error).
120		183
		184	=back
		185
121	=cut	186	=cut
122		187
123	package IO::AIO;	188	package IO::AIO;
		189
		190	use Carp ();
124		191
125	no warnings;	192	no warnings;
126	use strict 'vars';	193	use strict 'vars';
127		194
128	use base 'Exporter';	195	use base 'Exporter';
129		196
130	BEGIN {	197	BEGIN {
131	our $VERSION = '2.0';	198	our $VERSION = '3.0';
132		199
133	our @AIO_REQ = qw(aio_sendfile aio_read aio_write aio_open aio_close aio_stat	200	our @AIO_REQ = qw(aio_sendfile aio_read aio_write aio_open aio_close
134	aio_lstat aio_unlink aio_rmdir aio_readdir aio_scandir aio_symlink	201	aio_stat aio_lstat aio_unlink aio_rmdir aio_readdir
135	aio_fsync aio_fdatasync aio_readahead aio_rename aio_link aio_move	202	aio_scandir aio_symlink aio_readlink aio_sync aio_fsync
136	aio_copy aio_group aio_nop aio_mknod);	203	aio_fdatasync aio_pathsync aio_readahead
		204	aio_rename aio_link aio_move aio_copy aio_group
		205	aio_nop aio_mknod aio_load aio_rmtree aio_mkdir aio_chown
		206	aio_chmod aio_utime aio_truncate);
		207
137	our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice));	208	our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice));
138	our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush	209	our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush
139	min_parallel max_parallel nreqs nready npending);	210	min_parallel max_parallel max_idle
		211	nreqs nready npending nthreads
		212	max_poll_time max_poll_reqs);
140		213
141	@IO::AIO::GRP::ISA = 'IO::AIO::REQ';	214	@IO::AIO::GRP::ISA = 'IO::AIO::REQ';
142		215
143	require XSLoader;	216	require XSLoader;
144	XSLoader::load ("IO::AIO", $VERSION);	217	XSLoader::load ("IO::AIO", $VERSION);
145	}	218	}
146		219
147	=head1 FUNCTIONS	220	=head1 FUNCTIONS
148		221
149	=head2 AIO FUNCTIONS	222	=head2 AIO REQUEST FUNCTIONS
150		223
151	All the C<aio_*> calls are more or less thin wrappers around the syscall	224	All the C<aio_*> calls are more or less thin wrappers around the syscall
152	with the same name (sans C<aio_>). The arguments are similar or identical,	225	with the same name (sans C<aio_>). The arguments are similar or identical,
153	and they all accept an additional (and optional) C<$callback> argument	226	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	227	which must be a code reference. This code reference will get called with
…		…
157	syscall has been executed asynchronously.	230	syscall has been executed asynchronously.
158		231
159	All functions expecting a filehandle keep a copy of the filehandle	232	All functions expecting a filehandle keep a copy of the filehandle
160	internally until the request has finished.	233	internally until the request has finished.
161		234
162	All requests return objects of type L<IO::AIO::REQ> that allow further	235	All functions return request objects of type L<IO::AIO::REQ> that allow
163	manipulation of those requests while they are in-flight.	236	further manipulation of those requests while they are in-flight.
164		237
165	The pathnames you pass to these routines I<must> be absolute and	238	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	239	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	240	request is being executed, the current working directory could have
168	changed. Alternatively, you can make sure that you never change the	241	changed. Alternatively, you can make sure that you never change the
169	current working directory.	242	current working directory anywhere in the program and then use relative
		243	paths.
170		244
171	To encode pathnames to byte form, either make sure you either: a)	245	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	246	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	247	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	248	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)	249	environment, d) use Glib::filename_from_unicode on unicode filenames or e)
176	use something else.	250	use something else to ensure your scalar has the correct contents.
		251
		252	This works, btw. independent of the internal UTF-8 bit, which IO::AIO
		253	handles correctly wether it is set or not.
177		254
178	=over 4	255	=over 4
179		256
180	=item $prev_pri = aioreq_pri [$pri]	257	=item $prev_pri = aioreq_pri [$pri]
181		258
…		…
201	aio_read $_[0], ..., sub {	278	aio_read $_[0], ..., sub {
202	...	279	...
203	};	280	};
204	};	281	};
205		282
		283
206	=item aioreq_nice $pri_adjust	284	=item aioreq_nice $pri_adjust
207		285
208	Similar to C<aioreq_pri>, but subtracts the given value from the current	286	Similar to C<aioreq_pri>, but subtracts the given value from the current
209	priority, so effects are cumulative.	287	priority, so the effect is cumulative.
		288
210		289
211	=item aio_open $pathname, $flags, $mode, $callback->($fh)	290	=item aio_open $pathname, $flags, $mode, $callback->($fh)
212		291
213	Asynchronously open or create a file and call the callback with a newly	292	Asynchronously open or create a file and call the callback with a newly
214	created filehandle for the file.	293	created filehandle for the file.
…		…
220	list. They are the same as used by C<sysopen>.	299	list. They are the same as used by C<sysopen>.
221		300
222	Likewise, C<$mode> specifies the mode of the newly created file, if it	301	Likewise, C<$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>,	302	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,	303	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).	304	and C<0666> or C<0777> if you do). Note that the C<$mode> will be modified
		305	by the umask in effect then the request is being executed, so better never
		306	change the umask.
226		307
227	Example:	308	Example:
228		309
229	aio_open "/etc/passwd", O_RDONLY, 0, sub {	310	aio_open "/etc/passwd", O_RDONLY, 0, sub {
230	if ($_[0]) {	311	if ($_[0]) {
…		…
233	} else {	314	} else {
234	die "open failed: $!\n";	315	die "open failed: $!\n";
235	}	316	}
236	};	317	};
237		318
		319
238	=item aio_close $fh, $callback->($status)	320	=item aio_close $fh, $callback->($status)
239		321
240	Asynchronously close a file and call the callback with the result	322	Asynchronously close a file and call the callback with the result
241	code. I<WARNING:> although accepted, you should not pass in a perl	323	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		324
246	This is supposed to be a bug in the API, so that might change. It's	325	Unfortunately, you can't do this to perl. Perl I<insists> very strongly on
247	therefore best to avoid this function.	326	closing the file descriptor associated with the filehandle itself.
		327
		328	Therefore, C<aio_close> will not close the filehandle - instead it will
		329	use dup2 to overwrite the file descriptor with the write-end of a pipe
		330	(the pipe fd will be created on demand and will be cached).
		331
		332	Or in other words: the file descriptor will be closed, but it will not be
		333	free for reuse until the perl filehandle is closed.
		334
		335	=cut
248		336
249	=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)	337	=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
250		338
251	=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)	339	=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
252		340
253	Reads or writes C<length> bytes from the specified C<fh> and C<offset>	341	Reads or writes C<$length> bytes from the specified C<$fh> and C<$offset>
254	into the scalar given by C<data> and offset C<dataoffset> and calls the	342	into the scalar given by C<$data> and offset C<$dataoffset> and calls the
255	callback without the actual number of bytes read (or -1 on error, just	343	callback without the actual number of bytes read (or -1 on error, just
256	like the syscall).	344	like the syscall).
257		345
		346	If C<$offset> is undefined, then the current file descriptor offset will
		347	be used (and updated), otherwise the file descriptor offset will not be
		348	changed by these calls.
		349
		350	If C<$length> is undefined in C<aio_write>, use the remaining length of C<$data>.
		351
		352	If C<$dataoffset> is less than zero, it will be counted from the end of
		353	C<$data>.
		354
258	The C<$data> scalar I<MUST NOT> be modified in any way while the request	355	The C<$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	356	is outstanding. Modifying it can result in segfaults or World War III (if
260	necessary/optional hardware is installed).	357	the necessary/optional hardware is installed).
261		358
262	Example: Read 15 bytes at offset 7 into scalar C<$buffer>, starting at	359	Example: Read 15 bytes at offset 7 into scalar C<$buffer>, starting at
263	offset C<0> within the scalar:	360	offset C<0> within the scalar:
264		361
265	aio_read $fh, 7, 15, $buffer, 0, sub {	362	aio_read $fh, 7, 15, $buffer, 0, sub {
266	$_[0] > 0 or die "read error: $!";	363	$_[0] > 0 or die "read error: $!";
267	print "read $_[0] bytes: <$buffer>\n";	364	print "read $_[0] bytes: <$buffer>\n";
268	};	365	};
		366
269		367
270	=item aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval)	368	=item aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval)
271		369
272	Tries to copy C<$length> bytes from C<$in_fh> to C<$out_fh>. It starts	370	Tries to copy C<$length> bytes from C<$in_fh> to C<$out_fh>. It starts
273	reading at byte offset C<$in_offset>, and starts writing at the current	371	reading at byte offset C<$in_offset>, and starts writing at the current
…		…
287	C<$in_fh> than are written, and there is no way to find out how many	385	C<$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	386	bytes have been read from C<aio_sendfile> alone, as C<aio_sendfile> only
289	provides the number of bytes written to C<$out_fh>. Only if the result	387	provides the number of bytes written to C<$out_fh>. Only if the result
290	value equals C<$length> one can assume that C<$length> bytes have been	388	value equals C<$length> one can assume that C<$length> bytes have been
291	read.	389	read.
		390
292		391
293	=item aio_readahead $fh,$offset,$length, $callback->($retval)	392	=item aio_readahead $fh,$offset,$length, $callback->($retval)
294		393
295	C<aio_readahead> populates the page cache with data from a file so that	394	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<$offset>	395	subsequent reads from that file will not block on disk I/O. The C<$offset>
…		…
302	file. The current file offset of the file is left unchanged.	401	file. The current file offset of the file is left unchanged.
303		402
304	If that syscall doesn't exist (likely if your OS isn't Linux) it will be	403	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.	404	emulated by simply reading the data, which would have a similar effect.
306		405
		406
307	=item aio_stat $fh_or_path, $callback->($status)	407	=item aio_stat $fh_or_path, $callback->($status)
308		408
309	=item aio_lstat $fh, $callback->($status)	409	=item aio_lstat $fh, $callback->($status)
310		410
311	Works like perl's C<stat> or C<lstat> in void context. The callback will	411	Works like perl's C<stat> or C<lstat> in void context. The callback will
…		…
324	aio_stat "/etc/passwd", sub {	424	aio_stat "/etc/passwd", sub {
325	$_[0] and die "stat failed: $!";	425	$_[0] and die "stat failed: $!";
326	print "size is ", -s _, "\n";	426	print "size is ", -s _, "\n";
327	};	427	};
328		428
		429
		430	=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
		431
		432	Works like perl's C<utime> function (including the special case of $atime
		433	and $mtime being undef). Fractional times are supported if the underlying
		434	syscalls support them.
		435
		436	When called with a pathname, uses utimes(2) if available, otherwise
		437	utime(2). If called on a file descriptor, uses futimes(2) if available,
		438	otherwise returns ENOSYS, so this is not portable.
		439
		440	Examples:
		441
		442	# set atime and mtime to current time (basically touch(1)):
		443	aio_utime "path", undef, undef;
		444	# set atime to current time and mtime to beginning of the epoch:
		445	aio_utime "path", time, undef; # undef==0
		446
		447
		448	=item aio_chown $fh_or_path, $uid, $gid, $callback->($status)
		449
		450	Works like perl's C<chown> function, except that C<undef> for either $uid
		451	or $gid is being interpreted as "do not change" (but -1 can also be used).
		452
		453	Examples:
		454
		455	# same as "chown root path" in the shell:
		456	aio_chown "path", 0, -1;
		457	# same as above:
		458	aio_chown "path", 0, undef;
		459
		460
		461	=item aio_truncate $fh_or_path, $offset, $callback->($status)
		462
		463	Works like truncate(2) or ftruncate(2).
		464
		465
		466	=item aio_chmod $fh_or_path, $mode, $callback->($status)
		467
		468	Works like perl's C<chmod> function.
		469
		470
329	=item aio_unlink $pathname, $callback->($status)	471	=item aio_unlink $pathname, $callback->($status)
330		472
331	Asynchronously unlink (delete) a file and call the callback with the	473	Asynchronously unlink (delete) a file and call the callback with the
332	result code.	474	result code.
333		475
		476
334	=item aio_mknod $path, $mode, $dev, $callback->($status)	477	=item aio_mknod $path, $mode, $dev, $callback->($status)
335		478
		479	[EXPERIMENTAL]
		480
336	Asynchronously create a device node (or fifo). See mknod(2): the only	481	Asynchronously create a device node (or fifo). See mknod(2).
337	portable value for C<$mode> is C<S_IFIFO> ored with permissions, and C<0>	482
338	for C<$dev>.	483	The only (POSIX-) portable way of calling this function is:
		484
		485	aio_mknod $path, IO::AIO::S_IFIFO \| $mode, 0, sub { ...
		486
339		487
340	=item aio_link $srcpath, $dstpath, $callback->($status)	488	=item aio_link $srcpath, $dstpath, $callback->($status)
341		489
342	Asynchronously create a new link to the existing object at C<$srcpath> at	490	Asynchronously create a new link to the existing object at C<$srcpath> at
343	the path C<$dstpath> and call the callback with the result code.	491	the path C<$dstpath> and call the callback with the result code.
344		492
		493
345	=item aio_symlink $srcpath, $dstpath, $callback->($status)	494	=item aio_symlink $srcpath, $dstpath, $callback->($status)
346		495
347	Asynchronously create a new symbolic link to the existing object at C<$srcpath> at	496	Asynchronously create a new symbolic link to the existing object at C<$srcpath> at
348	the path C<$dstpath> and call the callback with the result code.	497	the path C<$dstpath> and call the callback with the result code.
349		498
		499
		500	=item aio_readlink $path, $callback->($link)
		501
		502	Asynchronously read the symlink specified by C<$path> and pass it to
		503	the callback. If an error occurs, nothing or undef gets passed to the
		504	callback.
		505
		506
350	=item aio_rename $srcpath, $dstpath, $callback->($status)	507	=item aio_rename $srcpath, $dstpath, $callback->($status)
351		508
352	Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as	509	Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as
353	rename(2) and call the callback with the result code.	510	rename(2) and call the callback with the result code.
354		511
		512
		513	=item aio_mkdir $pathname, $mode, $callback->($status)
		514
		515	Asynchronously mkdir (create) a directory and call the callback with
		516	the result code. C<$mode> will be modified by the umask at the time the
		517	request is executed, so do not change your umask.
		518
		519
355	=item aio_rmdir $pathname, $callback->($status)	520	=item aio_rmdir $pathname, $callback->($status)
356		521
357	Asynchronously rmdir (delete) a directory and call the callback with the	522	Asynchronously rmdir (delete) a directory and call the callback with the
358	result code.	523	result code.
		524
359		525
360	=item aio_readdir $pathname, $callback->($entries)	526	=item aio_readdir $pathname, $callback->($entries)
361		527
362	Unlike the POSIX call of the same name, C<aio_readdir> reads an entire	528	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	529	directory (i.e. opendir + readdir + closedir). The entries will not be
364	sorted, and will B<NOT> include the C<.> and C<..> entries.	530	sorted, and will B<NOT> include the C<.> and C<..> entries.
365		531
366	The callback a single argument which is either C<undef> or an array-ref	532	The callback a single argument which is either C<undef> or an array-ref
367	with the filenames.	533	with the filenames.
		534
		535
		536	=item aio_load $path, $data, $callback->($status)
		537
		538	This is a composite request that tries to fully load the given file into
		539	memory. Status is the same as with aio_read.
		540
		541	=cut
		542
		543	sub aio_load($$;$) {
		544	my ($path, undef, $cb) = @_;
		545	my $data = \$_[1];
		546
		547	my $pri = aioreq_pri;
		548	my $grp = aio_group $cb;
		549
		550	aioreq_pri $pri;
		551	add $grp aio_open $path, O_RDONLY, 0, sub {
		552	my $fh = shift
		553	or return $grp->result (-1);
		554
		555	aioreq_pri $pri;
		556	add $grp aio_read $fh, 0, (-s $fh), $$data, 0, sub {
		557	$grp->result ($_[0]);
		558	};
		559	};
		560
		561	$grp
		562	}
368		563
369	=item aio_copy $srcpath, $dstpath, $callback->($status)	564	=item aio_copy $srcpath, $dstpath, $callback->($status)
370		565
371	Try to copy the I<file> (directories not supported as either source or	566	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	567	destination) from C<$srcpath> to C<$dstpath> and call the callback with
…		…
405		600
406	# those should not normally block. should. should.	601	# those should not normally block. should. should.
407	utime $stat[8], $stat[9], $dst;	602	utime $stat[8], $stat[9], $dst;
408	chmod $stat[2] & 07777, $dst_fh;	603	chmod $stat[2] & 07777, $dst_fh;
409	chown $stat[4], $stat[5], $dst_fh;	604	chown $stat[4], $stat[5], $dst_fh;
		605
		606	aioreq_pri $pri;
410	close $dst_fh;	607	add $grp aio_close $dst_fh;
411	} else {	608	} else {
412	$grp->result (-1);	609	$grp->result (-1);
413	close $src_fh;	610	close $src_fh;
414	close $dst_fh;	611	close $dst_fh;
415		612
…		…
520	as those tend to return 0 or 1 as link counts, which disables the	717	as those tend to return 0 or 1 as link counts, which disables the
521	directory counting heuristic.	718	directory counting heuristic.
522		719
523	=cut	720	=cut
524		721
525	sub aio_scandir($$$) {	722	sub aio_scandir($$;$) {
526	my ($path, $maxreq, $cb) = @_;	723	my ($path, $maxreq, $cb) = @_;
527		724
528	my $pri = aioreq_pri;	725	my $pri = aioreq_pri;
529		726
530	my $grp = aio_group $cb;	727	my $grp = aio_group $cb;
…		…
606	};	803	};
607		804
608	$grp	805	$grp
609	}	806	}
610		807
		808	=item aio_rmtree $path, $callback->($status)
		809
		810	Delete a directory tree starting (and including) C<$path>, return the
		811	status of the final C<rmdir> only. This is a composite request that
		812	uses C<aio_scandir> to recurse into and rmdir directories, and unlink
		813	everything else.
		814
		815	=cut
		816
		817	sub aio_rmtree;
		818	sub aio_rmtree($;$) {
		819	my ($path, $cb) = @_;
		820
		821	my $pri = aioreq_pri;
		822	my $grp = aio_group $cb;
		823
		824	aioreq_pri $pri;
		825	add $grp aio_scandir $path, 0, sub {
		826	my ($dirs, $nondirs) = @_;
		827
		828	my $dirgrp = aio_group sub {
		829	add $grp aio_rmdir $path, sub {
		830	$grp->result ($_[0]);
		831	};
		832	};
		833
		834	(aioreq_pri $pri), add $dirgrp aio_rmtree "$path/$_" for @$dirs;
		835	(aioreq_pri $pri), add $dirgrp aio_unlink "$path/$_" for @$nondirs;
		836
		837	add $grp $dirgrp;
		838	};
		839
		840	$grp
		841	}
		842
		843	=item aio_sync $callback->($status)
		844
		845	Asynchronously call sync and call the callback when finished.
		846
611	=item aio_fsync $fh, $callback->($status)	847	=item aio_fsync $fh, $callback->($status)
612		848
613	Asynchronously call fsync on the given filehandle and call the callback	849	Asynchronously call fsync on the given filehandle and call the callback
614	with the fsync result code.	850	with the fsync result code.
615		851
…		…
618	Asynchronously call fdatasync on the given filehandle and call the	854	Asynchronously call fdatasync on the given filehandle and call the
619	callback with the fdatasync result code.	855	callback with the fdatasync result code.
620		856
621	If this call isn't available because your OS lacks it or it couldn't be	857	If this call isn't available because your OS lacks it or it couldn't be
622	detected, it will be emulated by calling C<fsync> instead.	858	detected, it will be emulated by calling C<fsync> instead.
		859
		860	=item aio_pathsync $path, $callback->($status)
		861
		862	This request tries to open, fsync and close the given path. This is a
		863	composite request intended tosync directories after directory operations
		864	(E.g. rename). This might not work on all operating systems or have any
		865	specific effect, but usually it makes sure that directory changes get
		866	written to disc. It works for anything that can be opened for read-only,
		867	not just directories.
		868
		869	Passes C<0> when everything went ok, and C<-1> on error.
		870
		871	=cut
		872
		873	sub aio_pathsync($;$) {
		874	my ($path, $cb) = @_;
		875
		876	my $pri = aioreq_pri;
		877	my $grp = aio_group $cb;
		878
		879	aioreq_pri $pri;
		880	add $grp aio_open $path, O_RDONLY, 0, sub {
		881	my ($fh) = @_;
		882	if ($fh) {
		883	aioreq_pri $pri;
		884	add $grp aio_fsync $fh, sub {
		885	$grp->result ($_[0]);
		886
		887	aioreq_pri $pri;
		888	add $grp aio_close $fh;
		889	};
		890	} else {
		891	$grp->result (-1);
		892	}
		893	};
		894
		895	$grp
		896	}
623		897
624	=item aio_group $callback->(...)	898	=item aio_group $callback->(...)
625		899
626	This is a very special aio request: Instead of doing something, it is a	900	This is a very special aio request: Instead of doing something, it is a
627	container for other aio requests, which is useful if you want to bundle	901	container for other aio requests, which is useful if you want to bundle
…		…
764	itself. Useful when you queued a lot of events but got a result early.	1038	itself. Useful when you queued a lot of events but got a result early.
765		1039
766	=item $grp->result (...)	1040	=item $grp->result (...)
767		1041
768	Set the result value(s) that will be passed to the group callback when all	1042	Set the result value(s) that will be passed to the group callback when all
769	subrequests have finished and set thre groups errno to the current value	1043	subrequests have finished and set the groups errno to the current value
770	of errno (just like calling C<errno> without an error number). By default,	1044	of errno (just like calling C<errno> without an error number). By default,
771	no argument will be passed and errno is zero.	1045	no argument will be passed and errno is zero.
772		1046
773	=item $grp->errno ([$errno])	1047	=item $grp->errno ([$errno])
774		1048
…		…
827		1101
828	=back	1102	=back
829		1103
830	=head2 SUPPORT FUNCTIONS	1104	=head2 SUPPORT FUNCTIONS
831		1105
		1106	=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION
		1107
832	=over 4	1108	=over 4
833		1109
834	=item $fileno = IO::AIO::poll_fileno	1110	=item $fileno = IO::AIO::poll_fileno
835		1111
836	Return the I<request result pipe file descriptor>. This filehandle must be	1112	Return the I<request result pipe file descriptor>. This filehandle must be
…		…
840		1116
841	See C<poll_cb> for an example.	1117	See C<poll_cb> for an example.
842		1118
843	=item IO::AIO::poll_cb	1119	=item IO::AIO::poll_cb
844		1120
845	Process all outstanding events on the result pipe. You have to call this	1121	Process some outstanding events on the result pipe. You have to call this
846	regularly. Returns the number of events processed. Returns immediately	1122	regularly. Returns the number of events processed. Returns immediately
847	when no events are outstanding.	1123	when no events are outstanding. The amount of events processed depends on
		1124	the settings of C<IO::AIO::max_poll_req> and C<IO::AIO::max_poll_time>.
848		1125
849	If not all requests were processed for whatever reason, the filehandle	1126	If not all requests were processed for whatever reason, the filehandle
850	will still be ready when C<poll_cb> returns.	1127	will still be ready when C<poll_cb> returns.
851		1128
852	Example: Install an Event watcher that automatically calls	1129	Example: Install an Event watcher that automatically calls
…		…
854		1131
855	Event->io (fd => IO::AIO::poll_fileno,	1132	Event->io (fd => IO::AIO::poll_fileno,
856	poll => 'r', async => 1,	1133	poll => 'r', async => 1,
857	cb => \&IO::AIO::poll_cb);	1134	cb => \&IO::AIO::poll_cb);
858		1135
859	=item IO::AIO::poll_some $max_requests	1136	=item IO::AIO::max_poll_reqs $nreqs
860		1137
861	Similar to C<poll_cb>, but only processes up to C<$max_requests> requests	1138	=item IO::AIO::max_poll_time $seconds
862	at a time.
863		1139
864	Useful if you want to ensure some level of interactiveness when perl is	1140	These set the maximum number of requests (default C<0>, meaning infinity)
865	not fast enough to process all requests in time.	1141	that are being processed by C<IO::AIO::poll_cb> in one call, respectively
		1142	the maximum amount of time (default C<0>, meaning infinity) spent in
		1143	C<IO::AIO::poll_cb> to process requests (more correctly the mininum amount
		1144	of time C<poll_cb> is allowed to use).
		1145
		1146	Setting C<max_poll_time> to a non-zero value creates an overhead of one
		1147	syscall per request processed, which is not normally a problem unless your
		1148	callbacks are really really fast or your OS is really really slow (I am
		1149	not mentioning Solaris here). Using C<max_poll_reqs> incurs no overhead.
		1150
		1151	Setting these is useful if you want to ensure some level of
		1152	interactiveness when perl is not fast enough to process all requests in
		1153	time.
		1154
		1155	For interactive programs, values such as C<0.01> to C<0.1> should be fine.
866		1156
867	Example: Install an Event watcher that automatically calls	1157	Example: Install an Event watcher that automatically calls
868	IO::AIO::poll_some with low priority, to ensure that other parts of the	1158	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.	1159	program get the CPU sometimes even under high AIO load.
870		1160
		1161	# try not to spend much more than 0.1s in poll_cb
		1162	IO::AIO::max_poll_time 0.1;
		1163
		1164	# use a low priority so other tasks have priority
871	Event->io (fd => IO::AIO::poll_fileno,	1165	Event->io (fd => IO::AIO::poll_fileno,
872	poll => 'r', nice => 1,	1166	poll => 'r', nice => 1,
873	cb => sub { IO::AIO::poll_some 256 });	1167	cb => &IO::AIO::poll_cb);
874		1168
875	=item IO::AIO::poll_wait	1169	=item IO::AIO::poll_wait
876		1170
		1171	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	1172	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	1173	does a C<select> on the filehandle. This is useful if you want to
879	for some requests to finish).	1174	synchronously wait for some requests to finish).
880		1175
881	See C<nreqs> for an example.	1176	See C<nreqs> for an example.
882		1177
		1178	=item IO::AIO::poll
		1179
		1180	Waits until some requests have been handled.
		1181
		1182	Returns the number of requests processed, but is otherwise strictly
		1183	equivalent to:
		1184
		1185	IO::AIO::poll_wait, IO::AIO::poll_cb
		1186
883	=item IO::AIO::nreqs	1187	=item IO::AIO::flush
884		1188
885	Returns the number of requests currently in the ready, execute or pending	1189	Wait till all outstanding AIO requests have been handled.
886	states (i.e. for which their callback has not been invoked yet).
887		1190
888	Example: wait till there are no outstanding requests anymore:	1191	Strictly equivalent to:
889		1192
890	IO::AIO::poll_wait, IO::AIO::poll_cb	1193	IO::AIO::poll_wait, IO::AIO::poll_cb
891	while IO::AIO::nreqs;	1194	while IO::AIO::nreqs;
892		1195
893	=item IO::AIO::nready	1196	=back
894		1197
895	Returns the number of requests currently in the ready state (not yet	1198	=head3 CONTROLLING THE NUMBER OF THREADS
896	executed).
897		1199
898	=item IO::AIO::npending	1200	=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		1201
921	=item IO::AIO::min_parallel $nthreads	1202	=item IO::AIO::min_parallel $nthreads
922		1203
923	Set the minimum number of AIO threads to C<$nthreads>. The current	1204	Set the minimum number of AIO threads to C<$nthreads>. The current
924	default is C<8>, which means eight asynchronous operations can execute	1205	default is C<8>, which means eight asynchronous operations can execute
925	concurrently at any one time (the number of outstanding requests,	1206	concurrently at any one time (the number of outstanding requests,
926	however, is unlimited).	1207	however, is unlimited).
927		1208
928	IO::AIO starts threads only on demand, when an AIO request is queued and	1209	IO::AIO starts threads only on demand, when an AIO request is queued and
929	no free thread exists.	1210	no free thread exists. Please note that queueing up a hundred requests can
		1211	create demand for a hundred threads, even if it turns out that everything
		1212	is in the cache and could have been processed faster by a single thread.
930		1213
931	It is recommended to keep the number of threads relatively low, as some	1214	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	1215	Linux kernel versions will scale negatively with the number of threads
933	(higher parallelity => MUCH higher latency). With current Linux 2.6	1216	(higher parallelity => MUCH higher latency). With current Linux 2.6
934	versions, 4-32 threads should be fine.	1217	versions, 4-32 threads should be fine.
…		…
948	This module automatically runs C<max_parallel 0> at program end, to ensure	1231	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.	1232	that all threads are killed and that there are no outstanding requests.
950		1233
951	Under normal circumstances you don't need to call this function.	1234	Under normal circumstances you don't need to call this function.
952		1235
		1236	=item IO::AIO::max_idle $nthreads
		1237
		1238	Limit the number of threads (default: 4) that are allowed to idle (i.e.,
		1239	threads that did not get a request to process within 10 seconds). That
		1240	means if a thread becomes idle while C<$nthreads> other threads are also
		1241	idle, it will free its resources and exit.
		1242
		1243	This is useful when you allow a large number of threads (e.g. 100 or 1000)
		1244	to allow for extremely high load situations, but want to free resources
		1245	under normal circumstances (1000 threads can easily consume 30MB of RAM).
		1246
		1247	The default is probably ok in most situations, especially if thread
		1248	creation is fast. If thread creation is very slow on your system you might
		1249	want to use larger values.
		1250
953	=item $oldmaxreqs = IO::AIO::max_outstanding $maxreqs	1251	=item IO::AIO::max_outstanding $maxreqs
954		1252
955	This is a very bad function to use in interactive programs because it	1253	This is a very bad function to use in interactive programs because it
956	blocks, and a bad way to reduce concurrency because it is inexact: Better	1254	blocks, and a bad way to reduce concurrency because it is inexact: Better
957	use an C<aio_group> together with a feed callback.	1255	use an C<aio_group> together with a feed callback.
958		1256
959	Sets the maximum number of outstanding requests to C<$nreqs>. If you	1257	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	1258	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>)	1259	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.	1260	function will block until the limit is no longer exceeded.
963		1261
964	The default value is very large, so there is no practical limit on the	1262	The default value is very large, so there is no practical limit on the
965	number of outstanding requests.	1263	number of outstanding requests.
966		1264
967	You can still queue as many requests as you want. Therefore,	1265	You can still queue as many requests as you want. Therefore,
968	C<max_oustsanding> is mainly useful in simple scripts (with low values) or	1266	C<max_outstanding> is mainly useful in simple scripts (with low values) or
969	as a stop gap to shield against fatal memory overflow (with large values).	1267	as a stop gap to shield against fatal memory overflow (with large values).
970		1268
971	=back	1269	=back
972		1270
		1271	=head3 STATISTICAL INFORMATION
		1272
		1273	=over
		1274
		1275	=item IO::AIO::nreqs
		1276
		1277	Returns the number of requests currently in the ready, execute or pending
		1278	states (i.e. for which their callback has not been invoked yet).
		1279
		1280	Example: wait till there are no outstanding requests anymore:
		1281
		1282	IO::AIO::poll_wait, IO::AIO::poll_cb
		1283	while IO::AIO::nreqs;
		1284
		1285	=item IO::AIO::nready
		1286
		1287	Returns the number of requests currently in the ready state (not yet
		1288	executed).
		1289
		1290	=item IO::AIO::npending
		1291
		1292	Returns the number of requests currently in the pending state (executed,
		1293	but not yet processed by poll_cb).
		1294
		1295	=back
		1296
973	=cut	1297	=cut
974		1298
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;	1299	min_parallel 8;
992		1300
993	END {	1301	END { flush }
994	flush;
995	};
996		1302
997	1;	1303	1;
998		1304
999	=head2 FORK BEHAVIOUR	1305	=head2 FORK BEHAVIOUR
1000		1306
…		…
1020	bytes of memory. In addition, stat requests need a stat buffer (possibly	1326	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	1327	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	1328	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.	1329	will consume memory till the request has entered the done state.
1024		1330
1025	This is now awfully much, so queuing lots of requests is not usually a	1331	This is not awfully much, so queuing lots of requests is not usually a
1026	problem.	1332	problem.
1027		1333
1028	Per-thread usage:	1334	Per-thread usage:
1029		1335
1030	In the execution phase, some aio requests require more memory for	1336	In the execution phase, some aio requests require more memory for
…		…
1035		1341
1036	Known bugs will be fixed in the next release.	1342	Known bugs will be fixed in the next release.
1037		1343
1038	=head1 SEE ALSO	1344	=head1 SEE ALSO
1039		1345
1040	L<Coro::AIO>.	1346	L<AnyEvent::AIO> for easy integration into event loops, L<Coro::AIO> for a
		1347	more natural syntax.
1041		1348
1042	=head1 AUTHOR	1349	=head1 AUTHOR
1043		1350
1044	Marc Lehmann <schmorp@schmorp.de>	1351	Marc Lehmann <schmorp@schmorp.de>
1045	http://home.schmorp.de/	1352	http://home.schmorp.de/

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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 1.125 by root, Sat May 10 22:47:34 2008 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 1.125 by root, Sat May 10 22:47:34 2008 UTC