[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 1.113 by root, Thu Sep 20 14:06:21 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
136	aio_copy aio_group aio_nop aio_mknod);	199	aio_move aio_copy aio_group aio_nop aio_mknod aio_load aio_rmtree aio_mkdir
		200	aio_chown aio_chmod aio_utime aio_truncate);
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<$dataoffset> and calls the
255	callback without the actual number of bytes read (or -1 on error, just	331	callback without the actual number of bytes read (or -1 on error, just
256	like the syscall).	332	like the syscall).
257		333
		334	If C<$offset> is undefined, then the current file descriptor offset will
		335	be used (and updated), otherwise the file descriptor offset will not be
		336	changed by these calls.
		337
		338	If C<$length> is undefined in C<aio_write>, use the remaining length of C<$data>.
		339
		340	If C<$dataoffset> is less than zero, it will be counted from the end of
		341	C<$data>.
		342
258	The C<$data> scalar I<MUST NOT> be modified in any way while the request	343	The C<$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	344	is outstanding. Modifying it can result in segfaults or World War III (if
260	necessary/optional hardware is installed).	345	the necessary/optional hardware is installed).
261		346
262	Example: Read 15 bytes at offset 7 into scalar C<$buffer>, starting at	347	Example: Read 15 bytes at offset 7 into scalar C<$buffer>, starting at
263	offset C<0> within the scalar:	348	offset C<0> within the scalar:
264		349
265	aio_read $fh, 7, 15, $buffer, 0, sub {	350	aio_read $fh, 7, 15, $buffer, 0, sub {
266	$_[0] > 0 or die "read error: $!";	351	$_[0] > 0 or die "read error: $!";
267	print "read $_[0] bytes: <$buffer>\n";	352	print "read $_[0] bytes: <$buffer>\n";
268	};	353	};
		354
269		355
270	=item aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval)	356	=item aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval)
271		357
272	Tries to copy C<$length> bytes from C<$in_fh> to C<$out_fh>. It starts	358	Tries to copy C<$length> bytes from C<$in_fh> to C<$out_fh>. It starts
273	reading at byte offset C<$in_offset>, and starts writing at the current	359	reading at byte offset C<$in_offset>, and starts writing at the current
…		…
287	C<$in_fh> than are written, and there is no way to find out how many	373	C<$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	374	bytes have been read from C<aio_sendfile> alone, as C<aio_sendfile> only
289	provides the number of bytes written to C<$out_fh>. Only if the result	375	provides the number of bytes written to C<$out_fh>. Only if the result
290	value equals C<$length> one can assume that C<$length> bytes have been	376	value equals C<$length> one can assume that C<$length> bytes have been
291	read.	377	read.
		378
292		379
293	=item aio_readahead $fh,$offset,$length, $callback->($retval)	380	=item aio_readahead $fh,$offset,$length, $callback->($retval)
294		381
295	C<aio_readahead> populates the page cache with data from a file so that	382	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<$offset>	383	subsequent reads from that file will not block on disk I/O. The C<$offset>
…		…
302	file. The current file offset of the file is left unchanged.	389	file. The current file offset of the file is left unchanged.
303		390
304	If that syscall doesn't exist (likely if your OS isn't Linux) it will be	391	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.	392	emulated by simply reading the data, which would have a similar effect.
306		393
		394
307	=item aio_stat $fh_or_path, $callback->($status)	395	=item aio_stat $fh_or_path, $callback->($status)
308		396
309	=item aio_lstat $fh, $callback->($status)	397	=item aio_lstat $fh, $callback->($status)
310		398
311	Works like perl's C<stat> or C<lstat> in void context. The callback will	399	Works like perl's C<stat> or C<lstat> in void context. The callback will
…		…
324	aio_stat "/etc/passwd", sub {	412	aio_stat "/etc/passwd", sub {
325	$_[0] and die "stat failed: $!";	413	$_[0] and die "stat failed: $!";
326	print "size is ", -s _, "\n";	414	print "size is ", -s _, "\n";
327	};	415	};
328		416
		417
		418	=item aio_utime $fh_or_path, $atime, $mtime, $callback->($status)
		419
		420	Works like perl's C<utime> function (including the special case of $atime
		421	and $mtime being undef). Fractional times are supported if the underlying
		422	syscalls support them.
		423
		424	When called with a pathname, uses utimes(2) if available, otherwise
		425	utime(2). If called on a file descriptor, uses futimes(2) if available,
		426	otherwise returns ENOSYS, so this is not portable.
		427
		428	Examples:
		429
		430	# set atime and mtime to current time (basically touch(1)):
		431	aio_utime "path", undef, undef;
		432	# set atime to current time and mtime to beginning of the epoch:
		433	aio_utime "path", time, undef; # undef==0
		434
		435
		436	=item aio_chown $fh_or_path, $uid, $gid, $callback->($status)
		437
		438	Works like perl's C<chown> function, except that C<undef> for either $uid
		439	or $gid is being interpreted as "do not change" (but -1 can also be used).
		440
		441	Examples:
		442
		443	# same as "chown root path" in the shell:
		444	aio_chown "path", 0, -1;
		445	# same as above:
		446	aio_chown "path", 0, undef;
		447
		448
		449	=item aio_truncate $fh_or_path, $offset, $callback->($status)
		450
		451	Works like truncate(2) or ftruncate(2).
		452
		453
		454	=item aio_chmod $fh_or_path, $mode, $callback->($status)
		455
		456	Works like perl's C<chmod> function.
		457
		458
329	=item aio_unlink $pathname, $callback->($status)	459	=item aio_unlink $pathname, $callback->($status)
330		460
331	Asynchronously unlink (delete) a file and call the callback with the	461	Asynchronously unlink (delete) a file and call the callback with the
332	result code.	462	result code.
333		463
		464
334	=item aio_mknod $path, $mode, $dev, $callback->($status)	465	=item aio_mknod $path, $mode, $dev, $callback->($status)
335		466
		467	[EXPERIMENTAL]
		468
336	Asynchronously create a device node (or fifo). See mknod(2): the only	469	Asynchronously create a device node (or fifo). See mknod(2).
337	portable value for C<$mode> is C<S_IFIFO> ored with permissions, and C<0>	470
338	for C<$dev>.	471	The only (POSIX-) portable way of calling this function is:
		472
		473	aio_mknod $path, IO::AIO::S_IFIFO \| $mode, 0, sub { ...
		474
339		475
340	=item aio_link $srcpath, $dstpath, $callback->($status)	476	=item aio_link $srcpath, $dstpath, $callback->($status)
341		477
342	Asynchronously create a new link to the existing object at C<$srcpath> at	478	Asynchronously create a new link to the existing object at C<$srcpath> at
343	the path C<$dstpath> and call the callback with the result code.	479	the path C<$dstpath> and call the callback with the result code.
344		480
		481
345	=item aio_symlink $srcpath, $dstpath, $callback->($status)	482	=item aio_symlink $srcpath, $dstpath, $callback->($status)
346		483
347	Asynchronously create a new symbolic link to the existing object at C<$srcpath> at	484	Asynchronously create a new symbolic link to the existing object at C<$srcpath> at
348	the path C<$dstpath> and call the callback with the result code.	485	the path C<$dstpath> and call the callback with the result code.
349		486
		487
		488	=item aio_readlink $path, $callback->($link)
		489
		490	Asynchronously read the symlink specified by C<$path> and pass it to
		491	the callback. If an error occurs, nothing or undef gets passed to the
		492	callback.
		493
		494
350	=item aio_rename $srcpath, $dstpath, $callback->($status)	495	=item aio_rename $srcpath, $dstpath, $callback->($status)
351		496
352	Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as	497	Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as
353	rename(2) and call the callback with the result code.	498	rename(2) and call the callback with the result code.
354		499
		500
		501	=item aio_mkdir $pathname, $mode, $callback->($status)
		502
		503	Asynchronously mkdir (create) a directory and call the callback with
		504	the result code. C<$mode> will be modified by the umask at the time the
		505	request is executed, so do not change your umask.
		506
		507
355	=item aio_rmdir $pathname, $callback->($status)	508	=item aio_rmdir $pathname, $callback->($status)
356		509
357	Asynchronously rmdir (delete) a directory and call the callback with the	510	Asynchronously rmdir (delete) a directory and call the callback with the
358	result code.	511	result code.
		512
359		513
360	=item aio_readdir $pathname, $callback->($entries)	514	=item aio_readdir $pathname, $callback->($entries)
361		515
362	Unlike the POSIX call of the same name, C<aio_readdir> reads an entire	516	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	517	directory (i.e. opendir + readdir + closedir). The entries will not be
364	sorted, and will B<NOT> include the C<.> and C<..> entries.	518	sorted, and will B<NOT> include the C<.> and C<..> entries.
365		519
366	The callback a single argument which is either C<undef> or an array-ref	520	The callback a single argument which is either C<undef> or an array-ref
367	with the filenames.	521	with the filenames.
		522
		523
		524	=item aio_load $path, $data, $callback->($status)
		525
		526	This is a composite request that tries to fully load the given file into
		527	memory. Status is the same as with aio_read.
		528
		529	=cut
		530
		531	sub aio_load($$;$) {
		532	aio_block {
		533	my ($path, undef, $cb) = @_;
		534	my $data = \$_[1];
		535
		536	my $pri = aioreq_pri;
		537	my $grp = aio_group $cb;
		538
		539	aioreq_pri $pri;
		540	add $grp aio_open $path, O_RDONLY, 0, sub {
		541	my $fh = shift
		542	or return $grp->result (-1);
		543
		544	aioreq_pri $pri;
		545	add $grp aio_read $fh, 0, (-s $fh), $$data, 0, sub {
		546	$grp->result ($_[0]);
		547	};
		548	};
		549
		550	$grp
		551	}
		552	}
368		553
369	=item aio_copy $srcpath, $dstpath, $callback->($status)	554	=item aio_copy $srcpath, $dstpath, $callback->($status)
370		555
371	Try to copy the I<file> (directories not supported as either source or	556	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	557	destination) from C<$srcpath> to C<$dstpath> and call the callback with
…		…
382	errors are being ignored.	567	errors are being ignored.
383		568
384	=cut	569	=cut
385		570
386	sub aio_copy($$;$) {	571	sub aio_copy($$;$) {
		572	aio_block {
387	my ($src, $dst, $cb) = @_;	573	my ($src, $dst, $cb) = @_;
388		574
389	my $pri = aioreq_pri;	575	my $pri = aioreq_pri;
390	my $grp = aio_group $cb;	576	my $grp = aio_group $cb;
391		577
392	aioreq_pri $pri;	578	aioreq_pri $pri;
393	add $grp aio_open $src, O_RDONLY, 0, sub {	579	add $grp aio_open $src, O_RDONLY, 0, sub {
394	if (my $src_fh = $_[0]) {	580	if (my $src_fh = $_[0]) {
395	my @stat = stat $src_fh;	581	my @stat = stat $src_fh;
396		582
397	aioreq_pri $pri;	583	aioreq_pri $pri;
398	add $grp aio_open $dst, O_CREAT \| O_WRONLY \| O_TRUNC, 0200, sub {	584	add $grp aio_open $dst, O_CREAT \| O_WRONLY \| O_TRUNC, 0200, sub {
399	if (my $dst_fh = $_[0]) {	585	if (my $dst_fh = $_[0]) {
400	aioreq_pri $pri;	586	aioreq_pri $pri;
401	add $grp aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub {	587	add $grp aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub {
402	if ($_[0] == $stat[7]) {	588	if ($_[0] == $stat[7]) {
403	$grp->result (0);	589	$grp->result (0);
404	close $src_fh;	590	close $src_fh;
405		591
406	# those should not normally block. should. should.	592	# those should not normally block. should. should.
407	utime $stat[8], $stat[9], $dst;	593	utime $stat[8], $stat[9], $dst;
408	chmod $stat[2] & 07777, $dst_fh;	594	chmod $stat[2] & 07777, $dst_fh;
409	chown $stat[4], $stat[5], $dst_fh;	595	chown $stat[4], $stat[5], $dst_fh;
410	close $dst_fh;	596	close $dst_fh;
411	} else {	597	} else {
412	$grp->result (-1);	598	$grp->result (-1);
413	close $src_fh;	599	close $src_fh;
414	close $dst_fh;	600	close $dst_fh;
415		601
416	aioreq $pri;	602	aioreq $pri;
417	add $grp aio_unlink $dst;	603	add $grp aio_unlink $dst;
		604	}
418	}	605	};
		606	} else {
		607	$grp->result (-1);
419	};	608	}
420	} else {
421	$grp->result (-1);
422	}	609	},
		610
		611	} else {
		612	$grp->result (-1);
423	},	613	}
424
425	} else {
426	$grp->result (-1);
427	}	614	};
		615
		616	$grp
428	};	617	}
429
430	$grp
431	}	618	}
432		619
433	=item aio_move $srcpath, $dstpath, $callback->($status)	620	=item aio_move $srcpath, $dstpath, $callback->($status)
434		621
435	Try to move the I<file> (directories not supported as either source or	622	Try to move the I<file> (directories not supported as either source or
…		…
441	that is successful, unlinking the C<$srcpath>.	628	that is successful, unlinking the C<$srcpath>.
442		629
443	=cut	630	=cut
444		631
445	sub aio_move($$;$) {	632	sub aio_move($$;$) {
		633	aio_block {
446	my ($src, $dst, $cb) = @_;	634	my ($src, $dst, $cb) = @_;
447		635
448	my $pri = aioreq_pri;	636	my $pri = aioreq_pri;
449	my $grp = aio_group $cb;	637	my $grp = aio_group $cb;
450		638
451	aioreq_pri $pri;	639	aioreq_pri $pri;
452	add $grp aio_rename $src, $dst, sub {	640	add $grp aio_rename $src, $dst, sub {
453	if ($_[0] && $! == EXDEV) {	641	if ($_[0] && $! == EXDEV) {
454	aioreq_pri $pri;	642	aioreq_pri $pri;
455	add $grp aio_copy $src, $dst, sub {	643	add $grp aio_copy $src, $dst, sub {
		644	$grp->result ($_[0]);
		645
		646	if (!$_[0]) {
		647	aioreq_pri $pri;
		648	add $grp aio_unlink $src;
		649	}
		650	};
		651	} else {
456	$grp->result ($_[0]);	652	$grp->result ($_[0]);
457
458	if (!$_[0]) {
459	aioreq_pri $pri;
460	add $grp aio_unlink $src;
461	}
462	};	653	}
463	} else {
464	$grp->result ($_[0]);
465	}	654	};
		655
		656	$grp
466	};	657	}
467
468	$grp
469	}	658	}
470		659
471	=item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs)	660	=item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs)
472		661
473	Scans a directory (similar to C<aio_readdir>) but additionally tries to	662	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	709	as those tend to return 0 or 1 as link counts, which disables the
521	directory counting heuristic.	710	directory counting heuristic.
522		711
523	=cut	712	=cut
524		713
525	sub aio_scandir($$$) {	714	sub aio_scandir($$;$) {
		715	aio_block {
526	my ($path, $maxreq, $cb) = @_;	716	my ($path, $maxreq, $cb) = @_;
527		717
528	my $pri = aioreq_pri;	718	my $pri = aioreq_pri;
529		719
530	my $grp = aio_group $cb;	720	my $grp = aio_group $cb;
531		721
532	$maxreq = 4 if $maxreq <= 0;	722	$maxreq = 4 if $maxreq <= 0;
533		723
534	# stat once	724	# 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;	725	aioreq_pri $pri;
543	add $grp aio_readdir $path, sub {	726	add $grp aio_stat $path, sub {
544	my $entries = shift
545	or return $grp->result ();	727	return $grp->result () if $_[0];
		728	my $now = time;
		729	my $hash1 = join ":", (stat _)[0,1,3,7,9];
546		730
547	# stat the dir another time	731	# read the directory entries
548	aioreq_pri $pri;	732	aioreq_pri $pri;
		733	add $grp aio_readdir $path, sub {
		734	my $entries = shift
		735	or return $grp->result ();
		736
		737	# stat the dir another time
		738	aioreq_pri $pri;
549	add $grp aio_stat $path, sub {	739	add $grp aio_stat $path, sub {
550	my $hash2 = join ":", (stat _)[0,1,3,7,9];	740	my $hash2 = join ":", (stat _)[0,1,3,7,9];
551		741
552	my $ndirs;	742	my $ndirs;
553		743
554	# take the slow route if anything looks fishy	744	# take the slow route if anything looks fishy
555	if ($hash1 ne $hash2 or (stat _)[9] == $now) {	745	if ($hash1 ne $hash2 or (stat _)[9] == $now) {
556	$ndirs = -1;	746	$ndirs = -1;
557	} else {	747	} else {
558	# if nlink == 2, we are finished	748	# if nlink == 2, we are finished
559	# on non-posix-fs's, we rely on nlink < 2	749	# on non-posix-fs's, we rely on nlink < 2
560	$ndirs = (stat _)[3] - 2	750	$ndirs = (stat _)[3] - 2
561	or return $grp->result ([], $entries);	751	or return $grp->result ([], $entries);
562	}	752	}
563		753
564	# sort into likely dirs and likely nondirs	754	# sort into likely dirs and likely nondirs
565	# dirs == files without ".", short entries first	755	# dirs == files without ".", short entries first
566	$entries = [map $_->[0],	756	$entries = [map $_->[0],
567	sort { $b->[1] cmp $a->[1] }	757	sort { $b->[1] cmp $a->[1] }
568	map [$_, sprintf "%s%04d", (/.\./ ? "1" : "0"), length],	758	map [$_, sprintf "%s%04d", (/.\./ ? "1" : "0"), length],
569	@$entries];	759	@$entries];
570		760
571	my (@dirs, @nondirs);	761	my (@dirs, @nondirs);
572		762
573	my $statgrp = add $grp aio_group sub {	763	my $statgrp = add $grp aio_group sub {
574	$grp->result (\@dirs, \@nondirs);	764	$grp->result (\@dirs, \@nondirs);
575	};	765	};
576		766
577	limit $statgrp $maxreq;	767	limit $statgrp $maxreq;
578	feed $statgrp sub {	768	feed $statgrp sub {
579	return unless @$entries;	769	return unless @$entries;
580	my $entry = pop @$entries;	770	my $entry = pop @$entries;
581		771
582	aioreq_pri $pri;	772	aioreq_pri $pri;
583	add $statgrp aio_stat "$path/$entry/.", sub {	773	add $statgrp aio_stat "$path/$entry/.", sub {
584	if ($_[0] < 0) {	774	if ($_[0] < 0) {
585	push @nondirs, $entry;	775	push @nondirs, $entry;
586	} else {	776	} else {
587	# need to check for real directory	777	# need to check for real directory
588	aioreq_pri $pri;	778	aioreq_pri $pri;
589	add $statgrp aio_lstat "$path/$entry", sub {	779	add $statgrp aio_lstat "$path/$entry", sub {
590	if (-d _) {	780	if (-d _) {
591	push @dirs, $entry;	781	push @dirs, $entry;
592		782
593	unless (--$ndirs) {	783	unless (--$ndirs) {
594	push @nondirs, @$entries;	784	push @nondirs, @$entries;
595	feed $statgrp;	785	feed $statgrp;
		786	}
		787	} else {
		788	push @nondirs, $entry;
596	}	789	}
597	} else {
598	push @nondirs, $entry;
599	}	790	}
600	}	791	}
601	}	792	};
602	};	793	};
603	};	794	};
604	};	795	};
605	};	796	};
		797
		798	$grp
606	};	799	}
		800	}
607		801
		802	=item aio_rmtree $path, $callback->($status)
		803
		804	Delete a directory tree starting (and including) C<$path>, return the
		805	status of the final C<rmdir> only. This is a composite request that
		806	uses C<aio_scandir> to recurse into and rmdir directories, and unlink
		807	everything else.
		808
		809	=cut
		810
		811	sub aio_rmtree;
		812	sub aio_rmtree($;$) {
		813	aio_block {
		814	my ($path, $cb) = @_;
		815
		816	my $pri = aioreq_pri;
		817	my $grp = aio_group $cb;
		818
		819	aioreq_pri $pri;
		820	add $grp aio_scandir $path, 0, sub {
		821	my ($dirs, $nondirs) = @_;
		822
		823	my $dirgrp = aio_group sub {
		824	add $grp aio_rmdir $path, sub {
		825	$grp->result ($_[0]);
		826	};
		827	};
		828
		829	(aioreq_pri $pri), add $dirgrp aio_rmtree "$path/$_" for @$dirs;
		830	(aioreq_pri $pri), add $dirgrp aio_unlink "$path/$_" for @$nondirs;
		831
		832	add $grp $dirgrp;
		833	};
		834
608	$grp	835	$grp
		836	}
609	}	837	}
610		838
611	=item aio_fsync $fh, $callback->($status)	839	=item aio_fsync $fh, $callback->($status)
612		840
613	Asynchronously call fsync on the given filehandle and call the callback	841	Asynchronously call fsync on the given filehandle and call the callback
…		…
827		1055
828	=back	1056	=back
829		1057
830	=head2 SUPPORT FUNCTIONS	1058	=head2 SUPPORT FUNCTIONS
831		1059
		1060	=head3 EVENT PROCESSING AND EVENT LOOP INTEGRATION
		1061
832	=over 4	1062	=over 4
833		1063
834	=item $fileno = IO::AIO::poll_fileno	1064	=item $fileno = IO::AIO::poll_fileno
835		1065
836	Return the I<request result pipe file descriptor>. This filehandle must be	1066	Return the I<request result pipe file descriptor>. This filehandle must be
…		…
840		1070
841	See C<poll_cb> for an example.	1071	See C<poll_cb> for an example.
842		1072
843	=item IO::AIO::poll_cb	1073	=item IO::AIO::poll_cb
844		1074
845	Process all outstanding events on the result pipe. You have to call this	1075	Process some outstanding events on the result pipe. You have to call this
846	regularly. Returns the number of events processed. Returns immediately	1076	regularly. Returns the number of events processed. Returns immediately
847	when no events are outstanding.	1077	when no events are outstanding. The amount of events processed depends on
		1078	the settings of C<IO::AIO::max_poll_req> and C<IO::AIO::max_poll_time>.
848		1079
849	If not all requests were processed for whatever reason, the filehandle	1080	If not all requests were processed for whatever reason, the filehandle
850	will still be ready when C<poll_cb> returns.	1081	will still be ready when C<poll_cb> returns.
851		1082
852	Example: Install an Event watcher that automatically calls	1083	Example: Install an Event watcher that automatically calls
…		…
854		1085
855	Event->io (fd => IO::AIO::poll_fileno,	1086	Event->io (fd => IO::AIO::poll_fileno,
856	poll => 'r', async => 1,	1087	poll => 'r', async => 1,
857	cb => \&IO::AIO::poll_cb);	1088	cb => \&IO::AIO::poll_cb);
858		1089
859	=item IO::AIO::poll_some $max_requests	1090	=item IO::AIO::max_poll_reqs $nreqs
860		1091
861	Similar to C<poll_cb>, but only processes up to C<$max_requests> requests	1092	=item IO::AIO::max_poll_time $seconds
862	at a time.
863		1093
864	Useful if you want to ensure some level of interactiveness when perl is	1094	These set the maximum number of requests (default C<0>, meaning infinity)
865	not fast enough to process all requests in time.	1095	that are being processed by C<IO::AIO::poll_cb> in one call, respectively
		1096	the maximum amount of time (default C<0>, meaning infinity) spent in
		1097	C<IO::AIO::poll_cb> to process requests (more correctly the mininum amount
		1098	of time C<poll_cb> is allowed to use).
		1099
		1100	Setting C<max_poll_time> to a non-zero value creates an overhead of one
		1101	syscall per request processed, which is not normally a problem unless your
		1102	callbacks are really really fast or your OS is really really slow (I am
		1103	not mentioning Solaris here). Using C<max_poll_reqs> incurs no overhead.
		1104
		1105	Setting these is useful if you want to ensure some level of
		1106	interactiveness when perl is not fast enough to process all requests in
		1107	time.
		1108
		1109	For interactive programs, values such as C<0.01> to C<0.1> should be fine.
866		1110
867	Example: Install an Event watcher that automatically calls	1111	Example: Install an Event watcher that automatically calls
868	IO::AIO::poll_some with low priority, to ensure that other parts of the	1112	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.	1113	program get the CPU sometimes even under high AIO load.
870		1114
		1115	# try not to spend much more than 0.1s in poll_cb
		1116	IO::AIO::max_poll_time 0.1;
		1117
		1118	# use a low priority so other tasks have priority
871	Event->io (fd => IO::AIO::poll_fileno,	1119	Event->io (fd => IO::AIO::poll_fileno,
872	poll => 'r', nice => 1,	1120	poll => 'r', nice => 1,
873	cb => sub { IO::AIO::poll_some 256 });	1121	cb => &IO::AIO::poll_cb);
874		1122
875	=item IO::AIO::poll_wait	1123	=item IO::AIO::poll_wait
876		1124
		1125	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	1126	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	1127	does a C<select> on the filehandle. This is useful if you want to
879	for some requests to finish).	1128	synchronously wait for some requests to finish).
880		1129
881	See C<nreqs> for an example.	1130	See C<nreqs> for an example.
882		1131
		1132	=item IO::AIO::poll
		1133
		1134	Waits until some requests have been handled.
		1135
		1136	Returns the number of requests processed, but is otherwise strictly
		1137	equivalent to:
		1138
		1139	IO::AIO::poll_wait, IO::AIO::poll_cb
		1140
883	=item IO::AIO::nreqs	1141	=item IO::AIO::flush
884		1142
885	Returns the number of requests currently in the ready, execute or pending	1143	Wait till all outstanding AIO requests have been handled.
886	states (i.e. for which their callback has not been invoked yet).
887		1144
888	Example: wait till there are no outstanding requests anymore:	1145	Strictly equivalent to:
889		1146
890	IO::AIO::poll_wait, IO::AIO::poll_cb	1147	IO::AIO::poll_wait, IO::AIO::poll_cb
891	while IO::AIO::nreqs;	1148	while IO::AIO::nreqs;
892		1149
893	=item IO::AIO::nready	1150	=back
894		1151
895	Returns the number of requests currently in the ready state (not yet	1152	=head3 CONTROLLING THE NUMBER OF THREADS
896	executed).
897		1153
898	=item IO::AIO::npending	1154	=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		1155
921	=item IO::AIO::min_parallel $nthreads	1156	=item IO::AIO::min_parallel $nthreads
922		1157
923	Set the minimum number of AIO threads to C<$nthreads>. The current	1158	Set the minimum number of AIO threads to C<$nthreads>. The current
924	default is C<8>, which means eight asynchronous operations can execute	1159	default is C<8>, which means eight asynchronous operations can execute
925	concurrently at any one time (the number of outstanding requests,	1160	concurrently at any one time (the number of outstanding requests,
926	however, is unlimited).	1161	however, is unlimited).
927		1162
928	IO::AIO starts threads only on demand, when an AIO request is queued and	1163	IO::AIO starts threads only on demand, when an AIO request is queued and
929	no free thread exists.	1164	no free thread exists. Please note that queueing up a hundred requests can
		1165	create demand for a hundred threads, even if it turns out that everything
		1166	is in the cache and could have been processed faster by a single thread.
930		1167
931	It is recommended to keep the number of threads relatively low, as some	1168	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	1169	Linux kernel versions will scale negatively with the number of threads
933	(higher parallelity => MUCH higher latency). With current Linux 2.6	1170	(higher parallelity => MUCH higher latency). With current Linux 2.6
934	versions, 4-32 threads should be fine.	1171	versions, 4-32 threads should be fine.
…		…
948	This module automatically runs C<max_parallel 0> at program end, to ensure	1185	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.	1186	that all threads are killed and that there are no outstanding requests.
950		1187
951	Under normal circumstances you don't need to call this function.	1188	Under normal circumstances you don't need to call this function.
952		1189
		1190	=item IO::AIO::max_idle $nthreads
		1191
		1192	Limit the number of threads (default: 4) that are allowed to idle (i.e.,
		1193	threads that did not get a request to process within 10 seconds). That
		1194	means if a thread becomes idle while C<$nthreads> other threads are also
		1195	idle, it will free its resources and exit.
		1196
		1197	This is useful when you allow a large number of threads (e.g. 100 or 1000)
		1198	to allow for extremely high load situations, but want to free resources
		1199	under normal circumstances (1000 threads can easily consume 30MB of RAM).
		1200
		1201	The default is probably ok in most situations, especially if thread
		1202	creation is fast. If thread creation is very slow on your system you might
		1203	want to use larger values.
		1204
953	=item $oldmaxreqs = IO::AIO::max_outstanding $maxreqs	1205	=item $oldmaxreqs = IO::AIO::max_outstanding $maxreqs
954		1206
955	This is a very bad function to use in interactive programs because it	1207	This is a very bad function to use in interactive programs because it
956	blocks, and a bad way to reduce concurrency because it is inexact: Better	1208	blocks, and a bad way to reduce concurrency because it is inexact: Better
957	use an C<aio_group> together with a feed callback.	1209	use an C<aio_group> together with a feed callback.
958		1210
959	Sets the maximum number of outstanding requests to C<$nreqs>. If you	1211	Sets the maximum number of outstanding requests to C<$nreqs>. If you
960	to queue up more than this number of requests, the next call to the	1212	do queue up more than this number of requests, the next call to the
961	C<poll_cb> (and C<poll_some> and other functions calling C<poll_cb>)	1213	C<poll_cb> (and C<poll_some> and other functions calling C<poll_cb>)
962	function will block until the limit is no longer exceeded.	1214	function will block until the limit is no longer exceeded.
963		1215
964	The default value is very large, so there is no practical limit on the	1216	The default value is very large, so there is no practical limit on the
965	number of outstanding requests.	1217	number of outstanding requests.
966		1218
967	You can still queue as many requests as you want. Therefore,	1219	You can still queue as many requests as you want. Therefore,
968	C<max_oustsanding> is mainly useful in simple scripts (with low values) or	1220	C<max_oustsanding> is mainly useful in simple scripts (with low values) or
969	as a stop gap to shield against fatal memory overflow (with large values).	1221	as a stop gap to shield against fatal memory overflow (with large values).
		1222
		1223	=back
		1224
		1225	=head3 STATISTICAL INFORMATION
		1226
		1227	=over
		1228
		1229	=item IO::AIO::nreqs
		1230
		1231	Returns the number of requests currently in the ready, execute or pending
		1232	states (i.e. for which their callback has not been invoked yet).
		1233
		1234	Example: wait till there are no outstanding requests anymore:
		1235
		1236	IO::AIO::poll_wait, IO::AIO::poll_cb
		1237	while IO::AIO::nreqs;
		1238
		1239	=item IO::AIO::nready
		1240
		1241	Returns the number of requests currently in the ready state (not yet
		1242	executed).
		1243
		1244	=item IO::AIO::npending
		1245
		1246	Returns the number of requests currently in the pending state (executed,
		1247	but not yet processed by poll_cb).
970		1248
971	=back	1249	=back
972		1250
973	=cut	1251	=cut
974		1252
…		…
988	*$sym	1266	*$sym
989	}	1267	}
990		1268
991	min_parallel 8;	1269	min_parallel 8;
992		1270
993	END {	1271	END { flush }
994	flush;
995	};
996		1272
997	1;	1273	1;
998		1274
999	=head2 FORK BEHAVIOUR	1275	=head2 FORK BEHAVIOUR
1000		1276
…		…
1020	bytes of memory. In addition, stat requests need a stat buffer (possibly	1296	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	1297	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	1298	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.	1299	will consume memory till the request has entered the done state.
1024		1300
1025	This is now awfully much, so queuing lots of requests is not usually a	1301	This is not awfully much, so queuing lots of requests is not usually a
1026	problem.	1302	problem.
1027		1303
1028	Per-thread usage:	1304	Per-thread usage:
1029		1305
1030	In the execution phase, some aio requests require more memory for	1306	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 1.113 by root, Thu Sep 20 14:06:21 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 1.113 by root, Thu Sep 20 14:06:21 2007 UTC