[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 1.108 by root, Fri Jun 1 13:25:50 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
…		…
50		51
51	=head1 DESCRIPTION	52	=head1 DESCRIPTION
52		53
53	This module implements asynchronous I/O using whatever means your	54	This module implements asynchronous I/O using whatever means your
54	operating system supports.	55	operating system supports.
		56
		57	Asynchronous means that operations that can normally block your program
		58	(e.g. reading from disk) will be done asynchronously: the operation
		59	will still block, but you can do something else in the meantime. This
		60	is extremely useful for programs that need to stay interactive even
		61	when doing heavy I/O (GUI programs, high performance network servers
		62	etc.), but can also be used to easily do operations in parallel that are
		63	normally done sequentially, e.g. stat'ing many files, which is much faster
		64	on a RAID volume or over NFS when you do a number of stat operations
		65	concurrently.
		66
		67	While most of this works on all types of file descriptors (for
		68	example sockets), using these functions on file descriptors that
		69	support nonblocking operation (again, sockets, pipes etc.) is very
		70	inefficient. Use an event loop for that (such as the L<Event\|Event>
		71	module): IO::AIO will naturally fit into such an event loop itself.
55		72
56	In this version, a number of threads are started that execute your	73	In this version, a number of threads are started that execute your
57	requests and signal their completion. You don't need thread support	74	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	75	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	76	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	77	functions available on many operating systems. However, they are often
61	not well-supported or restricted (Linux doesn't allow them on normal	78	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	79	files currently, for example), and they would only support aio_read and
63	aio_write, so the remaining functionality would have to be implemented	80	aio_write, so the remaining functionality would have to be implemented
64	using threads anyway.	81	using threads anyway.
65		82
66	Although the module will work with in the presence of other (Perl-)	83	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	84	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	85	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.	86	call C<poll_cb> (or other C<aio_> functions) recursively.
		87
		88	=head2 EXAMPLE
		89
		90	This is a simple example that uses the Event module and loads
		91	F</etc/passwd> asynchronously:
		92
		93	use Fcntl;
		94	use Event;
		95	use IO::AIO;
		96
		97	# register the IO::AIO callback with Event
		98	Event->io (fd => IO::AIO::poll_fileno,
		99	poll => 'r',
		100	cb => \&IO::AIO::poll_cb);
		101
		102	# queue the request to open /etc/passwd
		103	aio_open "/etc/passwd", O_RDONLY, 0, sub {
		104	my $fh = shift
		105	or die "error while opening: $!";
		106
		107	# stat'ing filehandles is generally non-blocking
		108	my $size = -s $fh;
		109
		110	# queue a request to read the file
		111	my $contents;
		112	aio_read $fh, 0, $size, $contents, 0, sub {
		113	$_[0] == $size
		114	or die "short read: $!";
		115
		116	close $fh;
		117
		118	# file contents now in $contents
		119	print $contents;
		120
		121	# exit event loop and program
		122	Event::unloop;
		123	};
		124	};
		125
		126	# possibly queue up other requests, or open GUI windows,
		127	# check for sockets etc. etc.
		128
		129	# process events as long as there are some:
		130	Event::loop;
70		131
71	=head1 REQUEST ANATOMY AND LIFETIME	132	=head1 REQUEST ANATOMY AND LIFETIME
72		133
73	Every C<aio_*> function creates a request. which is a C data structure not	134	Every C<aio_*> function creates a request. which is a C data structure not
74	directly visible to Perl.	135	directly visible to Perl.
…		…
116	Request has reached the end of its lifetime and holds no resources anymore	177	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	178	(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	179	aio request is severed and calling its methods will either do nothing or
119	result in a runtime error).	180	result in a runtime error).
120		181
		182	=back
		183
121	=cut	184	=cut
122		185
123	package IO::AIO;	186	package IO::AIO;
124		187
125	no warnings;	188	no warnings;
126	use strict 'vars';	189	use strict 'vars';
127		190
128	use base 'Exporter';	191	use base 'Exporter';
129		192
130	BEGIN {	193	BEGIN {
131	our $VERSION = '2.0';	194	our $VERSION = '2.4';
132		195
133	our @AIO_REQ = qw(aio_sendfile aio_read aio_write aio_open aio_close aio_stat	196	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	197	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	198	aio_readlink aio_fsync aio_fdatasync aio_readahead aio_rename aio_link
		199	aio_move aio_copy aio_group aio_nop aio_mknod aio_load aio_rmtree aio_mkdir
136	aio_copy aio_group aio_nop aio_mknod);	200	aio_chown aio_chmod aio_utime);
137	our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice));	201	our @EXPORT = (@AIO_REQ, qw(aioreq_pri aioreq_nice aio_block));
138	our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush	202	our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush
139	min_parallel max_parallel nreqs nready npending);	203	min_parallel max_parallel max_idle
		204	nreqs nready npending nthreads
		205	max_poll_time max_poll_reqs);
140		206
141	@IO::AIO::GRP::ISA = 'IO::AIO::REQ';	207	@IO::AIO::GRP::ISA = 'IO::AIO::REQ';
142		208
143	require XSLoader;	209	require XSLoader;
144	XSLoader::load ("IO::AIO", $VERSION);	210	XSLoader::load ("IO::AIO", $VERSION);
145	}	211	}
146		212
147	=head1 FUNCTIONS	213	=head1 FUNCTIONS
148		214
149	=head2 AIO FUNCTIONS	215	=head2 AIO REQUEST FUNCTIONS
150		216
151	All the C<aio_*> calls are more or less thin wrappers around the syscall	217	All the C<aio_*> calls are more or less thin wrappers around the syscall
152	with the same name (sans C<aio_>). The arguments are similar or identical,	218	with the same name (sans C<aio_>). The arguments are similar or identical,
153	and they all accept an additional (and optional) C<$callback> argument	219	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	220	which must be a code reference. This code reference will get called with
…		…
157	syscall has been executed asynchronously.	223	syscall has been executed asynchronously.
158		224
159	All functions expecting a filehandle keep a copy of the filehandle	225	All functions expecting a filehandle keep a copy of the filehandle
160	internally until the request has finished.	226	internally until the request has finished.
161		227
162	All requests return objects of type L<IO::AIO::REQ> that allow further	228	All functions return request objects of type L<IO::AIO::REQ> that allow
163	manipulation of those requests while they are in-flight.	229	further manipulation of those requests while they are in-flight.
164		230
165	The pathnames you pass to these routines I<must> be absolute and	231	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	232	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	233	request is being executed, the current working directory could have
168	changed. Alternatively, you can make sure that you never change the	234	changed. Alternatively, you can make sure that you never change the
169	current working directory.	235	current working directory anywhere in the program and then use relative
		236	paths.
170		237
171	To encode pathnames to byte form, either make sure you either: a)	238	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	239	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	240	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	241	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)	242	environment, d) use Glib::filename_from_unicode on unicode filenames or e)
176	use something else.	243	use something else to ensure your scalar has the correct contents.
		244
		245	This works, btw. independent of the internal UTF-8 bit, which IO::AIO
		246	handles correctly wether it is set or not.
177		247
178	=over 4	248	=over 4
179		249
180	=item $prev_pri = aioreq_pri [$pri]	250	=item $prev_pri = aioreq_pri [$pri]
181		251
…		…
201	aio_read $_[0], ..., sub {	271	aio_read $_[0], ..., sub {
202	...	272	...
203	};	273	};
204	};	274	};
205		275
		276
206	=item aioreq_nice $pri_adjust	277	=item aioreq_nice $pri_adjust
207		278
208	Similar to C<aioreq_pri>, but subtracts the given value from the current	279	Similar to C<aioreq_pri>, but subtracts the given value from the current
209	priority, so effects are cumulative.	280	priority, so the effect is cumulative.
		281
210		282
211	=item aio_open $pathname, $flags, $mode, $callback->($fh)	283	=item aio_open $pathname, $flags, $mode, $callback->($fh)
212		284
213	Asynchronously open or create a file and call the callback with a newly	285	Asynchronously open or create a file and call the callback with a newly
214	created filehandle for the file.	286	created filehandle for the file.
…		…
220	list. They are the same as used by C<sysopen>.	292	list. They are the same as used by C<sysopen>.
221		293
222	Likewise, C<$mode> specifies the mode of the newly created file, if it	294	Likewise, C<$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>,	295	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,	296	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).	297	and C<0666> or C<0777> if you do). Note that the C<$mode> will be modified
		298	by the umask in effect then the request is being executed, so better never
		299	change the umask.
226		300
227	Example:	301	Example:
228		302
229	aio_open "/etc/passwd", O_RDONLY, 0, sub {	303	aio_open "/etc/passwd", O_RDONLY, 0, sub {
230	if ($_[0]) {	304	if ($_[0]) {
…		…
233	} else {	307	} else {
234	die "open failed: $!\n";	308	die "open failed: $!\n";
235	}	309	}
236	};	310	};
237		311
		312
238	=item aio_close $fh, $callback->($status)	313	=item aio_close $fh, $callback->($status)
239		314
240	Asynchronously close a file and call the callback with the result	315	Asynchronously close a file and call the callback with the result
241	code. I<WARNING:> although accepted, you should not pass in a perl	316	code. I<WARNING:> although accepted, you should not pass in a perl
242	filehandle here, as perl will likely close the file descriptor another	317	filehandle here, as perl will likely close the file descriptor another
…		…
244	C<close> or just let filehandles go out of scope.	319	C<close> or just let filehandles go out of scope.
245		320
246	This is supposed to be a bug in the API, so that might change. It's	321	This is supposed to be a bug in the API, so that might change. It's
247	therefore best to avoid this function.	322	therefore best to avoid this function.
248		323
		324
249	=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)	325	=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
250		326
251	=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)	327	=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
252		328
253	Reads or writes C<length> bytes from the specified C<fh> and C<offset>	329	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	330	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	331	callback without the actual number of bytes read (or -1 on error, just
256	like the syscall).	332	like the syscall). If C<offset> is undefined, then the current file offset
		333	will be used (and updated), otherwise the file offset will not be changed
		334	by these calls.
257		335
258	The C<$data> scalar I<MUST NOT> be modified in any way while the request	336	The C<$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	337	is outstanding. Modifying it can result in segfaults or World War III (if
260	necessary/optional hardware is installed).	338	the necessary/optional hardware is installed).
261		339
262	Example: Read 15 bytes at offset 7 into scalar C<$buffer>, starting at	340	Example: Read 15 bytes at offset 7 into scalar C<$buffer>, starting at
263	offset C<0> within the scalar:	341	offset C<0> within the scalar:
264		342
265	aio_read $fh, 7, 15, $buffer, 0, sub {	343	aio_read $fh, 7, 15, $buffer, 0, sub {
266	$_[0] > 0 or die "read error: $!";	344	$_[0] > 0 or die "read error: $!";
267	print "read $_[0] bytes: <$buffer>\n";	345	print "read $_[0] bytes: <$buffer>\n";
268	};	346	};
		347
269		348
270	=item aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval)	349	=item aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval)
271		350
272	Tries to copy C<$length> bytes from C<$in_fh> to C<$out_fh>. It starts	351	Tries to copy C<$length> bytes from C<$in_fh> to C<$out_fh>. It starts
273	reading at byte offset C<$in_offset>, and starts writing at the current	352	reading at byte offset C<$in_offset>, and starts writing at the current
…		…
287	C<$in_fh> than are written, and there is no way to find out how many	366	C<$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	367	bytes have been read from C<aio_sendfile> alone, as C<aio_sendfile> only
289	provides the number of bytes written to C<$out_fh>. Only if the result	368	provides the number of bytes written to C<$out_fh>. Only if the result
290	value equals C<$length> one can assume that C<$length> bytes have been	369	value equals C<$length> one can assume that C<$length> bytes have been
291	read.	370	read.
		371
292		372
293	=item aio_readahead $fh,$offset,$length, $callback->($retval)	373	=item aio_readahead $fh,$offset,$length, $callback->($retval)
294		374
295	C<aio_readahead> populates the page cache with data from a file so that	375	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<$offset>	376	subsequent reads from that file will not block on disk I/O. The C<$offset>
…		…
302	file. The current file offset of the file is left unchanged.	382	file. The current file offset of the file is left unchanged.
303		383
304	If that syscall doesn't exist (likely if your OS isn't Linux) it will be	384	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.	385	emulated by simply reading the data, which would have a similar effect.
306		386
		387
307	=item aio_stat $fh_or_path, $callback->($status)	388	=item aio_stat $fh_or_path, $callback->($status)
308		389
309	=item aio_lstat $fh, $callback->($status)	390	=item aio_lstat $fh, $callback->($status)
310		391
311	Works like perl's C<stat> or C<lstat> in void context. The callback will	392	Works like perl's C<stat> or C<lstat> in void context. The callback will
…		…
324	aio_stat "/etc/passwd", sub {	405	aio_stat "/etc/passwd", sub {
325	$_[0] and die "stat failed: $!";	406	$_[0] and die "stat failed: $!";
326	print "size is ", -s _, "\n";	407	print "size is ", -s _, "\n";
327	};	408	};
328		409
		410
		411	=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
		412
		413	Works like perl's C<utime> function (including the special case of $atime
		414	and $mtime being undef). Fractional times are supported if the underlying
		415	syscalls support them.
		416
		417	When called with a pathname, uses utimes(2) if available, otherwise
		418	utime(2). If called on a file descriptor, uses futimes(2) if available,
		419	otherwise returns ENOSYS, so this is not portable.
		420
		421	Examples:
		422
		423	# set atime and mtime to current time (basically touch(1)):
		424	aio_utime "path", undef, undef;
		425	# set atime to current time and mtime to beginning of the epoch:
		426	aio_utime "path", time, undef; # undef==0
		427
		428
		429	=item aio_chown $fh_or_path, $uid, $gid, $callback->($status)
		430
		431	Works like perl's C<chown> function, except that C<undef> for either $uid
		432	or $gid is being interpreted as "do not change" (but -1 can also be used).
		433
		434	Examples:
		435
		436	# same as "chown root path" in the shell:
		437	aio_chown "path", 0, -1;
		438	# same as above:
		439	aio_chown "path", 0, undef;
		440
		441
		442	=item aio_chmod $fh_or_path, $mode, $callback->($status)
		443
		444	Works like perl's C<chmod> function.
		445
		446
329	=item aio_unlink $pathname, $callback->($status)	447	=item aio_unlink $pathname, $callback->($status)
330		448
331	Asynchronously unlink (delete) a file and call the callback with the	449	Asynchronously unlink (delete) a file and call the callback with the
332	result code.	450	result code.
333		451
		452
334	=item aio_mknod $path, $mode, $dev, $callback->($status)	453	=item aio_mknod $path, $mode, $dev, $callback->($status)
335		454
		455	[EXPERIMENTAL]
		456
336	Asynchronously create a device node (or fifo). See mknod(2): the only	457	Asynchronously create a device node (or fifo). See mknod(2).
337	portable value for C<$mode> is C<S_IFIFO> ored with permissions, and C<0>	458
338	for C<$dev>.	459	The only (POSIX-) portable way of calling this function is:
		460
		461	aio_mknod $path, IO::AIO::S_IFIFO \| $mode, 0, sub { ...
		462
339		463
340	=item aio_link $srcpath, $dstpath, $callback->($status)	464	=item aio_link $srcpath, $dstpath, $callback->($status)
341		465
342	Asynchronously create a new link to the existing object at C<$srcpath> at	466	Asynchronously create a new link to the existing object at C<$srcpath> at
343	the path C<$dstpath> and call the callback with the result code.	467	the path C<$dstpath> and call the callback with the result code.
344		468
		469
345	=item aio_symlink $srcpath, $dstpath, $callback->($status)	470	=item aio_symlink $srcpath, $dstpath, $callback->($status)
346		471
347	Asynchronously create a new symbolic link to the existing object at C<$srcpath> at	472	Asynchronously create a new symbolic link to the existing object at C<$srcpath> at
348	the path C<$dstpath> and call the callback with the result code.	473	the path C<$dstpath> and call the callback with the result code.
349		474
		475
		476	=item aio_readlink $path, $callback->($link)
		477
		478	Asynchronously read the symlink specified by C<$path> and pass it to
		479	the callback. If an error occurs, nothing or undef gets passed to the
		480	callback.
		481
		482
350	=item aio_rename $srcpath, $dstpath, $callback->($status)	483	=item aio_rename $srcpath, $dstpath, $callback->($status)
351		484
352	Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as	485	Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as
353	rename(2) and call the callback with the result code.	486	rename(2) and call the callback with the result code.
354		487
		488
		489	=item aio_mkdir $pathname, $mode, $callback->($status)
		490
		491	Asynchronously mkdir (create) a directory and call the callback with
		492	the result code. C<$mode> will be modified by the umask at the time the
		493	request is executed, so do not change your umask.
		494
		495
355	=item aio_rmdir $pathname, $callback->($status)	496	=item aio_rmdir $pathname, $callback->($status)
356		497
357	Asynchronously rmdir (delete) a directory and call the callback with the	498	Asynchronously rmdir (delete) a directory and call the callback with the
358	result code.	499	result code.
		500
359		501
360	=item aio_readdir $pathname, $callback->($entries)	502	=item aio_readdir $pathname, $callback->($entries)
361		503
362	Unlike the POSIX call of the same name, C<aio_readdir> reads an entire	504	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	505	directory (i.e. opendir + readdir + closedir). The entries will not be
364	sorted, and will B<NOT> include the C<.> and C<..> entries.	506	sorted, and will B<NOT> include the C<.> and C<..> entries.
365		507
366	The callback a single argument which is either C<undef> or an array-ref	508	The callback a single argument which is either C<undef> or an array-ref
367	with the filenames.	509	with the filenames.
		510
		511
		512	=item aio_load $path, $data, $callback->($status)
		513
		514	This is a composite request that tries to fully load the given file into
		515	memory. Status is the same as with aio_read.
		516
		517	=cut
		518
		519	sub aio_load($$;$) {
		520	aio_block {
		521	my ($path, undef, $cb) = @_;
		522	my $data = \$_[1];
		523
		524	my $pri = aioreq_pri;
		525	my $grp = aio_group $cb;
		526
		527	aioreq_pri $pri;
		528	add $grp aio_open $path, O_RDONLY, 0, sub {
		529	my $fh = shift
		530	or return $grp->result (-1);
		531
		532	aioreq_pri $pri;
		533	add $grp aio_read $fh, 0, (-s $fh), $$data, 0, sub {
		534	$grp->result ($_[0]);
		535	};
		536	};
		537
		538	$grp
		539	}
		540	}
368		541
369	=item aio_copy $srcpath, $dstpath, $callback->($status)	542	=item aio_copy $srcpath, $dstpath, $callback->($status)
370		543
371	Try to copy the I<file> (directories not supported as either source or	544	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	545	destination) from C<$srcpath> to C<$dstpath> and call the callback with
…		…
382	errors are being ignored.	555	errors are being ignored.
383		556
384	=cut	557	=cut
385		558
386	sub aio_copy($$;$) {	559	sub aio_copy($$;$) {
		560	aio_block {
387	my ($src, $dst, $cb) = @_;	561	my ($src, $dst, $cb) = @_;
388		562
389	my $pri = aioreq_pri;	563	my $pri = aioreq_pri;
390	my $grp = aio_group $cb;	564	my $grp = aio_group $cb;
391		565
392	aioreq_pri $pri;	566	aioreq_pri $pri;
393	add $grp aio_open $src, O_RDONLY, 0, sub {	567	add $grp aio_open $src, O_RDONLY, 0, sub {
394	if (my $src_fh = $_[0]) {	568	if (my $src_fh = $_[0]) {
395	my @stat = stat $src_fh;	569	my @stat = stat $src_fh;
396		570
397	aioreq_pri $pri;	571	aioreq_pri $pri;
398	add $grp aio_open $dst, O_CREAT \| O_WRONLY \| O_TRUNC, 0200, sub {	572	add $grp aio_open $dst, O_CREAT \| O_WRONLY \| O_TRUNC, 0200, sub {
399	if (my $dst_fh = $_[0]) {	573	if (my $dst_fh = $_[0]) {
400	aioreq_pri $pri;	574	aioreq_pri $pri;
401	add $grp aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub {	575	add $grp aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub {
402	if ($_[0] == $stat[7]) {	576	if ($_[0] == $stat[7]) {
403	$grp->result (0);	577	$grp->result (0);
404	close $src_fh;	578	close $src_fh;
405		579
406	# those should not normally block. should. should.	580	# those should not normally block. should. should.
407	utime $stat[8], $stat[9], $dst;	581	utime $stat[8], $stat[9], $dst;
408	chmod $stat[2] & 07777, $dst_fh;	582	chmod $stat[2] & 07777, $dst_fh;
409	chown $stat[4], $stat[5], $dst_fh;	583	chown $stat[4], $stat[5], $dst_fh;
410	close $dst_fh;	584	close $dst_fh;
411	} else {	585	} else {
412	$grp->result (-1);	586	$grp->result (-1);
413	close $src_fh;	587	close $src_fh;
414	close $dst_fh;	588	close $dst_fh;
415		589
416	aioreq $pri;	590	aioreq $pri;
417	add $grp aio_unlink $dst;	591	add $grp aio_unlink $dst;
		592	}
418	}	593	};
		594	} else {
		595	$grp->result (-1);
419	};	596	}
420	} else {
421	$grp->result (-1);
422	}	597	},
		598
		599	} else {
		600	$grp->result (-1);
423	},	601	}
424
425	} else {
426	$grp->result (-1);
427	}	602	};
		603
		604	$grp
428	};	605	}
429
430	$grp
431	}	606	}
432		607
433	=item aio_move $srcpath, $dstpath, $callback->($status)	608	=item aio_move $srcpath, $dstpath, $callback->($status)
434		609
435	Try to move the I<file> (directories not supported as either source or	610	Try to move the I<file> (directories not supported as either source or
…		…
441	that is successful, unlinking the C<$srcpath>.	616	that is successful, unlinking the C<$srcpath>.
442		617
443	=cut	618	=cut
444		619
445	sub aio_move($$;$) {	620	sub aio_move($$;$) {
		621	aio_block {
446	my ($src, $dst, $cb) = @_;	622	my ($src, $dst, $cb) = @_;
447		623
448	my $pri = aioreq_pri;	624	my $pri = aioreq_pri;
449	my $grp = aio_group $cb;	625	my $grp = aio_group $cb;
450		626
451	aioreq_pri $pri;	627	aioreq_pri $pri;
452	add $grp aio_rename $src, $dst, sub {	628	add $grp aio_rename $src, $dst, sub {
453	if ($_[0] && $! == EXDEV) {	629	if ($_[0] && $! == EXDEV) {
454	aioreq_pri $pri;	630	aioreq_pri $pri;
455	add $grp aio_copy $src, $dst, sub {	631	add $grp aio_copy $src, $dst, sub {
		632	$grp->result ($_[0]);
		633
		634	if (!$_[0]) {
		635	aioreq_pri $pri;
		636	add $grp aio_unlink $src;
		637	}
		638	};
		639	} else {
456	$grp->result ($_[0]);	640	$grp->result ($_[0]);
457
458	if (!$_[0]) {
459	aioreq_pri $pri;
460	add $grp aio_unlink $src;
461	}
462	};	641	}
463	} else {
464	$grp->result ($_[0]);
465	}	642	};
		643
		644	$grp
466	};	645	}
467
468	$grp
469	}	646	}
470		647
471	=item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs)	648	=item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs)
472		649
473	Scans a directory (similar to C<aio_readdir>) but additionally tries to	650	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	697	as those tend to return 0 or 1 as link counts, which disables the
521	directory counting heuristic.	698	directory counting heuristic.
522		699
523	=cut	700	=cut
524		701
525	sub aio_scandir($$$) {	702	sub aio_scandir($$;$) {
		703	aio_block {
526	my ($path, $maxreq, $cb) = @_;	704	my ($path, $maxreq, $cb) = @_;
527		705
528	my $pri = aioreq_pri;	706	my $pri = aioreq_pri;
529		707
530	my $grp = aio_group $cb;	708	my $grp = aio_group $cb;
531		709
532	$maxreq = 4 if $maxreq <= 0;	710	$maxreq = 4 if $maxreq <= 0;
533		711
534	# stat once	712	# 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;	713	aioreq_pri $pri;
543	add $grp aio_readdir $path, sub {	714	add $grp aio_stat $path, sub {
544	my $entries = shift
545	or return $grp->result ();	715	return $grp->result () if $_[0];
		716	my $now = time;
		717	my $hash1 = join ":", (stat _)[0,1,3,7,9];
546		718
547	# stat the dir another time	719	# read the directory entries
548	aioreq_pri $pri;	720	aioreq_pri $pri;
		721	add $grp aio_readdir $path, sub {
		722	my $entries = shift
		723	or return $grp->result ();
		724
		725	# stat the dir another time
		726	aioreq_pri $pri;
549	add $grp aio_stat $path, sub {	727	add $grp aio_stat $path, sub {
550	my $hash2 = join ":", (stat _)[0,1,3,7,9];	728	my $hash2 = join ":", (stat _)[0,1,3,7,9];
551		729
552	my $ndirs;	730	my $ndirs;
553		731
554	# take the slow route if anything looks fishy	732	# take the slow route if anything looks fishy
555	if ($hash1 ne $hash2 or (stat _)[9] == $now) {	733	if ($hash1 ne $hash2 or (stat _)[9] == $now) {
556	$ndirs = -1;	734	$ndirs = -1;
557	} else {	735	} else {
558	# if nlink == 2, we are finished	736	# if nlink == 2, we are finished
559	# on non-posix-fs's, we rely on nlink < 2	737	# on non-posix-fs's, we rely on nlink < 2
560	$ndirs = (stat _)[3] - 2	738	$ndirs = (stat _)[3] - 2
561	or return $grp->result ([], $entries);	739	or return $grp->result ([], $entries);
562	}	740	}
563		741
564	# sort into likely dirs and likely nondirs	742	# sort into likely dirs and likely nondirs
565	# dirs == files without ".", short entries first	743	# dirs == files without ".", short entries first
566	$entries = [map $_->[0],	744	$entries = [map $_->[0],
567	sort { $b->[1] cmp $a->[1] }	745	sort { $b->[1] cmp $a->[1] }
568	map [$_, sprintf "%s%04d", (/.\./ ? "1" : "0"), length],	746	map [$_, sprintf "%s%04d", (/.\./ ? "1" : "0"), length],
569	@$entries];	747	@$entries];
570		748
571	my (@dirs, @nondirs);	749	my (@dirs, @nondirs);
572		750
573	my $statgrp = add $grp aio_group sub {	751	my $statgrp = add $grp aio_group sub {
574	$grp->result (\@dirs, \@nondirs);	752	$grp->result (\@dirs, \@nondirs);
575	};	753	};
576		754
577	limit $statgrp $maxreq;	755	limit $statgrp $maxreq;
578	feed $statgrp sub {	756	feed $statgrp sub {
579	return unless @$entries;	757	return unless @$entries;
580	my $entry = pop @$entries;	758	my $entry = pop @$entries;
581		759
582	aioreq_pri $pri;	760	aioreq_pri $pri;
583	add $statgrp aio_stat "$path/$entry/.", sub {	761	add $statgrp aio_stat "$path/$entry/.", sub {
584	if ($_[0] < 0) {	762	if ($_[0] < 0) {
585	push @nondirs, $entry;	763	push @nondirs, $entry;
586	} else {	764	} else {
587	# need to check for real directory	765	# need to check for real directory
588	aioreq_pri $pri;	766	aioreq_pri $pri;
589	add $statgrp aio_lstat "$path/$entry", sub {	767	add $statgrp aio_lstat "$path/$entry", sub {
590	if (-d _) {	768	if (-d _) {
591	push @dirs, $entry;	769	push @dirs, $entry;
592		770
593	unless (--$ndirs) {	771	unless (--$ndirs) {
594	push @nondirs, @$entries;	772	push @nondirs, @$entries;
595	feed $statgrp;	773	feed $statgrp;
		774	}
		775	} else {
		776	push @nondirs, $entry;
596	}	777	}
597	} else {
598	push @nondirs, $entry;
599	}	778	}
600	}	779	}
601	}	780	};
602	};	781	};
603	};	782	};
604	};	783	};
605	};	784	};
		785
		786	$grp
606	};	787	}
		788	}
607		789
		790	=item aio_rmtree $path, $callback->($status)
		791
		792	Delete a directory tree starting (and including) C<$path>, return the
		793	status of the final C<rmdir> only. This is a composite request that
		794	uses C<aio_scandir> to recurse into and rmdir directories, and unlink
		795	everything else.
		796
		797	=cut
		798
		799	sub aio_rmtree;
		800	sub aio_rmtree($;$) {
		801	aio_block {
		802	my ($path, $cb) = @_;
		803
		804	my $pri = aioreq_pri;
		805	my $grp = aio_group $cb;
		806
		807	aioreq_pri $pri;
		808	add $grp aio_scandir $path, 0, sub {
		809	my ($dirs, $nondirs) = @_;
		810
		811	my $dirgrp = aio_group sub {
		812	add $grp aio_rmdir $path, sub {
		813	$grp->result ($_[0]);
		814	};
		815	};
		816
		817	(aioreq_pri $pri), add $dirgrp aio_rmtree "$path/$_" for @$dirs;
		818	(aioreq_pri $pri), add $dirgrp aio_unlink "$path/$_" for @$nondirs;
		819
		820	add $grp $dirgrp;
		821	};
		822
608	$grp	823	$grp
		824	}
609	}	825	}
610		826
611	=item aio_fsync $fh, $callback->($status)	827	=item aio_fsync $fh, $callback->($status)
612		828
613	Asynchronously call fsync on the given filehandle and call the callback	829	Asynchronously call fsync on the given filehandle and call the callback
…		…
827		1043
828	=back	1044	=back
829		1045
830	=head2 SUPPORT FUNCTIONS	1046	=head2 SUPPORT FUNCTIONS
831		1047
		1048	=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION
		1049
832	=over 4	1050	=over 4
833		1051
834	=item $fileno = IO::AIO::poll_fileno	1052	=item $fileno = IO::AIO::poll_fileno
835		1053
836	Return the I<request result pipe file descriptor>. This filehandle must be	1054	Return the I<request result pipe file descriptor>. This filehandle must be
…		…
840		1058
841	See C<poll_cb> for an example.	1059	See C<poll_cb> for an example.
842		1060
843	=item IO::AIO::poll_cb	1061	=item IO::AIO::poll_cb
844		1062
845	Process all outstanding events on the result pipe. You have to call this	1063	Process some outstanding events on the result pipe. You have to call this
846	regularly. Returns the number of events processed. Returns immediately	1064	regularly. Returns the number of events processed. Returns immediately
847	when no events are outstanding.	1065	when no events are outstanding. The amount of events processed depends on
		1066	the settings of C<IO::AIO::max_poll_req> and C<IO::AIO::max_poll_time>.
848		1067
849	If not all requests were processed for whatever reason, the filehandle	1068	If not all requests were processed for whatever reason, the filehandle
850	will still be ready when C<poll_cb> returns.	1069	will still be ready when C<poll_cb> returns.
851		1070
852	Example: Install an Event watcher that automatically calls	1071	Example: Install an Event watcher that automatically calls
…		…
854		1073
855	Event->io (fd => IO::AIO::poll_fileno,	1074	Event->io (fd => IO::AIO::poll_fileno,
856	poll => 'r', async => 1,	1075	poll => 'r', async => 1,
857	cb => \&IO::AIO::poll_cb);	1076	cb => \&IO::AIO::poll_cb);
858		1077
859	=item IO::AIO::poll_some $max_requests	1078	=item IO::AIO::max_poll_reqs $nreqs
860		1079
861	Similar to C<poll_cb>, but only processes up to C<$max_requests> requests	1080	=item IO::AIO::max_poll_time $seconds
862	at a time.
863		1081
864	Useful if you want to ensure some level of interactiveness when perl is	1082	These set the maximum number of requests (default C<0>, meaning infinity)
865	not fast enough to process all requests in time.	1083	that are being processed by C<IO::AIO::poll_cb> in one call, respectively
		1084	the maximum amount of time (default C<0>, meaning infinity) spent in
		1085	C<IO::AIO::poll_cb> to process requests (more correctly the mininum amount
		1086	of time C<poll_cb> is allowed to use).
		1087
		1088	Setting C<max_poll_time> to a non-zero value creates an overhead of one
		1089	syscall per request processed, which is not normally a problem unless your
		1090	callbacks are really really fast or your OS is really really slow (I am
		1091	not mentioning Solaris here). Using C<max_poll_reqs> incurs no overhead.
		1092
		1093	Setting these is useful if you want to ensure some level of
		1094	interactiveness when perl is not fast enough to process all requests in
		1095	time.
		1096
		1097	For interactive programs, values such as C<0.01> to C<0.1> should be fine.
866		1098
867	Example: Install an Event watcher that automatically calls	1099	Example: Install an Event watcher that automatically calls
868	IO::AIO::poll_some with low priority, to ensure that other parts of the	1100	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.	1101	program get the CPU sometimes even under high AIO load.
870		1102
		1103	# try not to spend much more than 0.1s in poll_cb
		1104	IO::AIO::max_poll_time 0.1;
		1105
		1106	# use a low priority so other tasks have priority
871	Event->io (fd => IO::AIO::poll_fileno,	1107	Event->io (fd => IO::AIO::poll_fileno,
872	poll => 'r', nice => 1,	1108	poll => 'r', nice => 1,
873	cb => sub { IO::AIO::poll_some 256 });	1109	cb => &IO::AIO::poll_cb);
874		1110
875	=item IO::AIO::poll_wait	1111	=item IO::AIO::poll_wait
876		1112
		1113	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	1114	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	1115	does a C<select> on the filehandle. This is useful if you want to
879	for some requests to finish).	1116	synchronously wait for some requests to finish).
880		1117
881	See C<nreqs> for an example.	1118	See C<nreqs> for an example.
882		1119
		1120	=item IO::AIO::poll
		1121
		1122	Waits until some requests have been handled.
		1123
		1124	Returns the number of requests processed, but is otherwise strictly
		1125	equivalent to:
		1126
		1127	IO::AIO::poll_wait, IO::AIO::poll_cb
		1128
883	=item IO::AIO::nreqs	1129	=item IO::AIO::flush
884		1130
885	Returns the number of requests currently in the ready, execute or pending	1131	Wait till all outstanding AIO requests have been handled.
886	states (i.e. for which their callback has not been invoked yet).
887		1132
888	Example: wait till there are no outstanding requests anymore:	1133	Strictly equivalent to:
889		1134
890	IO::AIO::poll_wait, IO::AIO::poll_cb	1135	IO::AIO::poll_wait, IO::AIO::poll_cb
891	while IO::AIO::nreqs;	1136	while IO::AIO::nreqs;
892		1137
893	=item IO::AIO::nready	1138	=back
894		1139
895	Returns the number of requests currently in the ready state (not yet	1140	=head3 CONTROLLING THE NUMBER OF THREADS
896	executed).
897		1141
898	=item IO::AIO::npending	1142	=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		1143
921	=item IO::AIO::min_parallel $nthreads	1144	=item IO::AIO::min_parallel $nthreads
922		1145
923	Set the minimum number of AIO threads to C<$nthreads>. The current	1146	Set the minimum number of AIO threads to C<$nthreads>. The current
924	default is C<8>, which means eight asynchronous operations can execute	1147	default is C<8>, which means eight asynchronous operations can execute
925	concurrently at any one time (the number of outstanding requests,	1148	concurrently at any one time (the number of outstanding requests,
926	however, is unlimited).	1149	however, is unlimited).
927		1150
928	IO::AIO starts threads only on demand, when an AIO request is queued and	1151	IO::AIO starts threads only on demand, when an AIO request is queued and
929	no free thread exists.	1152	no free thread exists. Please note that queueing up a hundred requests can
		1153	create demand for a hundred threads, even if it turns out that everything
		1154	is in the cache and could have been processed faster by a single thread.
930		1155
931	It is recommended to keep the number of threads relatively low, as some	1156	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	1157	Linux kernel versions will scale negatively with the number of threads
933	(higher parallelity => MUCH higher latency). With current Linux 2.6	1158	(higher parallelity => MUCH higher latency). With current Linux 2.6
934	versions, 4-32 threads should be fine.	1159	versions, 4-32 threads should be fine.
…		…
948	This module automatically runs C<max_parallel 0> at program end, to ensure	1173	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.	1174	that all threads are killed and that there are no outstanding requests.
950		1175
951	Under normal circumstances you don't need to call this function.	1176	Under normal circumstances you don't need to call this function.
952		1177
		1178	=item IO::AIO::max_idle $nthreads
		1179
		1180	Limit the number of threads (default: 4) that are allowed to idle (i.e.,
		1181	threads that did not get a request to process within 10 seconds). That
		1182	means if a thread becomes idle while C<$nthreads> other threads are also
		1183	idle, it will free its resources and exit.
		1184
		1185	This is useful when you allow a large number of threads (e.g. 100 or 1000)
		1186	to allow for extremely high load situations, but want to free resources
		1187	under normal circumstances (1000 threads can easily consume 30MB of RAM).
		1188
		1189	The default is probably ok in most situations, especially if thread
		1190	creation is fast. If thread creation is very slow on your system you might
		1191	want to use larger values.
		1192
953	=item $oldmaxreqs = IO::AIO::max_outstanding $maxreqs	1193	=item $oldmaxreqs = IO::AIO::max_outstanding $maxreqs
954		1194
955	This is a very bad function to use in interactive programs because it	1195	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	1196	blocks, and a bad way to reduce concurrency because it is inexact: Better
957	use an C<aio_group> together with a feed callback.	1197	use an C<aio_group> together with a feed callback.
…		…
968	C<max_oustsanding> is mainly useful in simple scripts (with low values) or	1208	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).	1209	as a stop gap to shield against fatal memory overflow (with large values).
970		1210
971	=back	1211	=back
972		1212
		1213	=head3 STATISTICAL INFORMATION
		1214
		1215	=over
		1216
		1217	=item IO::AIO::nreqs
		1218
		1219	Returns the number of requests currently in the ready, execute or pending
		1220	states (i.e. for which their callback has not been invoked yet).
		1221
		1222	Example: wait till there are no outstanding requests anymore:
		1223
		1224	IO::AIO::poll_wait, IO::AIO::poll_cb
		1225	while IO::AIO::nreqs;
		1226
		1227	=item IO::AIO::nready
		1228
		1229	Returns the number of requests currently in the ready state (not yet
		1230	executed).
		1231
		1232	=item IO::AIO::npending
		1233
		1234	Returns the number of requests currently in the pending state (executed,
		1235	but not yet processed by poll_cb).
		1236
		1237	=back
		1238
973	=cut	1239	=cut
974		1240
975	# support function to convert a fd into a perl filehandle	1241	# support function to convert a fd into a perl filehandle
976	sub _fd2fh {	1242	sub _fd2fh {
977	return undef if $_[0] < 0;	1243	return undef if $_[0] < 0;
…		…
988	*$sym	1254	*$sym
989	}	1255	}
990		1256
991	min_parallel 8;	1257	min_parallel 8;
992		1258
993	END {	1259	END { flush }
994	flush;
995	};
996		1260
997	1;	1261	1;
998		1262
999	=head2 FORK BEHAVIOUR	1263	=head2 FORK BEHAVIOUR
1000		1264

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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 1.108 by root, Fri Jun 1 13:25:50 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 1.108 by root, Fri Jun 1 13:25:50 2007 UTC