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

Comparing IO-AIO/AIO.pm (file contents):
Revision 1.32 by root, Wed Aug 17 05:26:20 2005 UTC vs.
Revision 1.47 by root, Thu Dec 29 15:44:13 2005 UTC

…		…
14	aio_unlink "/tmp/file", sub { };	14	aio_unlink "/tmp/file", sub { };
15		15
16	aio_read $fh, 30000, 1024, $buffer, 0, sub {	16	aio_read $fh, 30000, 1024, $buffer, 0, sub {
17	$_[0] > 0 or die "read error: $!";	17	$_[0] > 0 or die "read error: $!";
18	};	18	};
		19
		20	# AnyEvent
		21	open my $fh, "<&=" . IO::AIO::poll_fileno or die "$!";
		22	my $w = AnyEvent->io (fh => $fh, poll => 'r', cb => sub { IO::AIO::poll_cb });
19		23
20	# Event	24	# Event
21	Event->io (fd => IO::AIO::poll_fileno,	25	Event->io (fd => IO::AIO::poll_fileno,
22	poll => 'r',	26	poll => 'r',
23	cb => \&IO::AIO::poll_cb);	27	cb => \&IO::AIO::poll_cb);
…		…
63	use base 'Exporter';	67	use base 'Exporter';
64		68
65	use Fcntl ();	69	use Fcntl ();
66		70
67	BEGIN {	71	BEGIN {
68	$VERSION = 1.3;	72	$VERSION = '1.72';
69		73
70
71	@EXPORT = qw(aio_read aio_write aio_open aio_close aio_stat aio_lstat aio_unlink	74	@EXPORT = qw(aio_sendfile aio_read aio_write aio_open aio_close aio_stat
		75	aio_lstat aio_unlink aio_rmdir aio_readdir aio_scandir aio_symlink
72	aio_rmdir aio_symlink aio_fsync aio_fdatasync aio_readahead);	76	aio_fsync aio_fdatasync aio_readahead);
73	@EXPORT_OK = qw(poll_fileno poll_cb min_parallel max_parallel max_outstanding nreqs);	77	@EXPORT_OK = qw(poll_fileno poll_cb min_parallel max_parallel
		78	max_outstanding nreqs);
74		79
75	require XSLoader;	80	require XSLoader;
76	XSLoader::load IO::AIO, $VERSION;	81	XSLoader::load IO::AIO, $VERSION;
77	}	82	}
78		83
…		…
104	environment, d) use Glib::filename_from_unicode on unicode filenames or e)	109	environment, d) use Glib::filename_from_unicode on unicode filenames or e)
105	use something else.	110	use something else.
106		111
107	=over 4	112	=over 4
108		113
109	=item aio_open $pathname, $flags, $mode, $callback	114	=item aio_open $pathname, $flags, $mode, $callback->($fh)
110		115
111	Asynchronously open or create a file and call the callback with a newly	116	Asynchronously open or create a file and call the callback with a newly
112	created filehandle for the file.	117	created filehandle for the file.
113		118
114	The pathname passed to C<aio_open> must be absolute. See API NOTES, above,	119	The pathname passed to C<aio_open> must be absolute. See API NOTES, above,
…		…
131	} else {	136	} else {
132	die "open failed: $!\n";	137	die "open failed: $!\n";
133	}	138	}
134	};	139	};
135		140
136	=item aio_close $fh, $callback	141	=item aio_close $fh, $callback->($status)
137		142
138	Asynchronously close a file and call the callback with the result	143	Asynchronously close a file and call the callback with the result
139	code. I<WARNING:> although accepted, you should not pass in a perl	144	code. I<WARNING:> although accepted, you should not pass in a perl
140	filehandle here, as perl will likely close the file descriptor another	145	filehandle here, as perl will likely close the file descriptor another
141	time when the filehandle is destroyed. Normally, you can safely call perls	146	time when the filehandle is destroyed. Normally, you can safely call perls
142	C<close> or just let filehandles go out of scope.	147	C<close> or just let filehandles go out of scope.
143		148
144	This is supposed to be a bug in the API, so that might change. It's	149	This is supposed to be a bug in the API, so that might change. It's
145	therefore best to avoid this function.	150	therefore best to avoid this function.
146		151
147	=item aio_read $fh,$offset,$length, $data,$dataoffset,$callback	152	=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
148		153
149	=item aio_write $fh,$offset,$length, $data,$dataoffset,$callback	154	=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
150		155
151	Reads or writes C<length> bytes from the specified C<fh> and C<offset>	156	Reads or writes C<length> bytes from the specified C<fh> and C<offset>
152	into the scalar given by C<data> and offset C<dataoffset> and calls the	157	into the scalar given by C<data> and offset C<dataoffset> and calls the
153	callback without the actual number of bytes read (or -1 on error, just	158	callback without the actual number of bytes read (or -1 on error, just
154	like the syscall).	159	like the syscall).
…		…
163	aio_read $fh, 7, 15, $buffer, 0, sub {	168	aio_read $fh, 7, 15, $buffer, 0, sub {
164	$_[0] > 0 or die "read error: $!";	169	$_[0] > 0 or die "read error: $!";
165	print "read $_[0] bytes: <$buffer>\n";	170	print "read $_[0] bytes: <$buffer>\n";
166	};	171	};
167		172
		173	=item aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval)
		174
		175	Tries to copy C<$length> bytes from C<$in_fh> to C<$out_fh>. It starts
		176	reading at byte offset C<$in_offset>, and starts writing at the current
		177	file offset of C<$out_fh>. Because of that, it is not safe to issue more
		178	than one C<aio_sendfile> per C<$out_fh>, as they will interfere with each
		179	other.
		180
		181	This call tries to make use of a native C<sendfile> syscall to provide
		182	zero-copy operation. For this to work, C<$out_fh> should refer to a
		183	socket, and C<$in_fh> should refer to mmap'able file.
		184
		185	If the native sendfile call fails or is not implemented, it will be
		186	emulated, so you can call C<aio_sendfile> on any type of filehandle
		187	regardless of the limitations of the operating system.
		188
		189	Please note, however, that C<aio_sendfile> can read more bytes from
		190	C<$in_fh> than are written, and there is no way to find out how many
		191	bytes have been read from C<aio_sendfile> alone, as C<aio_sendfile> only
		192	provides the number of bytes written to C<$out_fh>. Only if the result
		193	value equals C<$length> one can assume that C<$length> bytes have been
		194	read.
		195
168	=item aio_readahead $fh,$offset,$length, $callback	196	=item aio_readahead $fh,$offset,$length, $callback->($retval)
169		197
170	C<aio_readahead> populates the page cache with data from a file so that	198	C<aio_readahead> populates the page cache with data from a file so that
171	subsequent reads from that file will not block on disk I/O. The C<$offset>	199	subsequent reads from that file will not block on disk I/O. The C<$offset>
172	argument specifies the starting point from which data is to be read and	200	argument specifies the starting point from which data is to be read and
173	C<$length> specifies the number of bytes to be read. I/O is performed in	201	C<$length> specifies the number of bytes to be read. I/O is performed in
…		…
177	file. The current file offset of the file is left unchanged.	205	file. The current file offset of the file is left unchanged.
178		206
179	If that syscall doesn't exist (likely if your OS isn't Linux) it will be	207	If that syscall doesn't exist (likely if your OS isn't Linux) it will be
180	emulated by simply reading the data, which would have a similar effect.	208	emulated by simply reading the data, which would have a similar effect.
181		209
182	=item aio_stat $fh_or_path, $callback	210	=item aio_stat $fh_or_path, $callback->($status)
183		211
184	=item aio_lstat $fh, $callback	212	=item aio_lstat $fh, $callback->($status)
185		213
186	Works like perl's C<stat> or C<lstat> in void context. The callback will	214	Works like perl's C<stat> or C<lstat> in void context. The callback will
187	be called after the stat and the results will be available using C<stat _>	215	be called after the stat and the results will be available using C<stat _>
188	or C<-s _> etc...	216	or C<-s _> etc...
189		217
…		…
199	aio_stat "/etc/passwd", sub {	227	aio_stat "/etc/passwd", sub {
200	$_[0] and die "stat failed: $!";	228	$_[0] and die "stat failed: $!";
201	print "size is ", -s _, "\n";	229	print "size is ", -s _, "\n";
202	};	230	};
203		231
204	=item aio_unlink $pathname, $callback	232	=item aio_unlink $pathname, $callback->($status)
205		233
206	Asynchronously unlink (delete) a file and call the callback with the	234	Asynchronously unlink (delete) a file and call the callback with the
207	result code.	235	result code.
208		236
209	=item aio_rmdir $pathname, $callback	237	=item aio_rmdir $pathname, $callback->($status)
210		238
211	Asynchronously rmdir (delete) a directory and call the callback with the	239	Asynchronously rmdir (delete) a directory and call the callback with the
212	result code.	240	result code.
213		241
		242	=item aio_readdir $pathname, $callback->($entries)
		243
		244	Unlike the POSIX call of the same name, C<aio_readdir> reads an entire
		245	directory (i.e. opendir + readdir + closedir). The entries will not be
		246	sorted, and will B<NOT> include the C<.> and C<..> entries.
		247
		248	The callback a single argument which is either C<undef> or an array-ref
		249	with the filenames.
		250
		251	=item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs)
		252
		253	Scans a directory (similar to C<aio_readdir>) and tries to separate the
		254	entries of directory C<$path> into two sets of names, ones you can recurse
		255	into (directories), and ones you cannot recurse into (everything else).
		256
		257	C<aio_scandir> is a composite request that consists of many
		258	aio-primitives. C<$maxreq> specifies the maximum number of outstanding
		259	aio requests that this function generates. If it is C<< <= 0 >>, then a
		260	suitable default will be chosen (currently 8).
		261
		262	On error, the callback is called without arguments, otherwise it receives
		263	two array-refs with path-relative entry names.
		264
		265	Example:
		266
		267	aio_scandir $dir, 0, sub {
		268	my ($dirs, $nondirs) = @_;
		269	print "real directories: @$dirs\n";
		270	print "everything else: @$nondirs\n";
		271	};
		272
		273	Implementation notes.
		274
		275	The C<aio_readdir> cannot be avoided, but C<stat()>'ing every entry can.
		276
		277	After reading the directory, the modification time, size etc. of the
		278	directory before and after the readdir is checked, and if they match, the
		279	link count will be used to decide how many entries are directories (if
		280	>= 2). Otherwise, no knowledge of the number of subdirectories will be
		281	assumed.
		282
		283	Then entires will be sorted into likely directories (everything without a
		284	non-initial dot) and likely non-directories (everything else). Then every
		285	entry + C</.> will be C<stat>'ed, likely directories first. This is often
		286	faster because filesystems might detect the type of the entry without
		287	reading the inode data (e.g. ext2s filetype feature). If that succeeds,
		288	it assumes that the entry is a directory or a symlink to directory (which
		289	will be checked seperately).
		290
		291	If the known number of directories has been reached, the rest of the
		292	entries is assumed to be non-directories.
		293
		294	=cut
		295
		296	sub aio_scandir($$$) {
		297	my ($path, $maxreq, $cb) = @_;
		298
		299	$maxreq = 8 if $maxreq <= 0;
		300
		301	# stat once
		302	aio_stat $path, sub {
		303	return $cb->() if $_[0];
		304	my $hash1 = join ":", (stat _)[0,1,3,7,9];
		305
		306	# read the directory entries
		307	aio_readdir $path, sub {
		308	my $entries = shift
		309	or return $cb->();
		310
		311	# stat the dir another time
		312	aio_stat $path, sub {
		313	my $hash2 = join ":", (stat _)[0,1,3,7,9];
		314
		315	my $ndirs;
		316
		317	# take the slow route if anything looks fishy
		318	if ($hash1 ne $hash2) {
		319	$ndirs = -1;
		320	} else {
		321	# if nlink == 2, we are finished
		322	# on non-posix-fs's, we rely on nlink < 2
		323	$ndirs = (stat _)[3] - 2
		324	or return $cb->([], $entries);
		325	}
		326
		327	# sort into likely dirs and likely nondirs
		328	# dirs == files without ".", short entries first
		329	$entries = [map $_->[0],
		330	sort { $b->[1] cmp $a->[1] }
		331	map [$_, sprintf "%s%04d", (/.\./ ? "1" : "0"), length],
		332	@$entries];
		333
		334	my (@dirs, @nondirs);
		335
		336	my ($statcb, $schedcb);
		337	my $nreq = 0;
		338
		339	$schedcb = sub {
		340	if (@$entries) {
		341	if ($nreq < $maxreq) {
		342	my $ent = pop @$entries;
		343	$nreq++;
		344	aio_stat "$path/$ent/.", sub { $statcb->($_[0], $ent) };
		345	}
		346	} elsif (!$nreq) {
		347	# finished
		348	undef $statcb;
		349	undef $schedcb;
		350	$cb->(\@dirs, \@nondirs) if $cb;
		351	undef $cb;
		352	}
		353	};
		354	$statcb = sub {
		355	my ($status, $entry) = @_;
		356
		357	if ($status < 0) {
		358	$nreq--;
		359	push @nondirs, $entry;
		360	&$schedcb;
		361	} else {
		362	# need to check for real directory
		363	aio_lstat "$path/$entry", sub {
		364	$nreq--;
		365
		366	if (-d _) {
		367	push @dirs, $entry;
		368
		369	if (!--$ndirs) {
		370	push @nondirs, @$entries;
		371	$entries = [];
		372	}
		373	} else {
		374	push @nondirs, $entry;
		375	}
		376
		377	&$schedcb;
		378	}
		379	}
		380	};
		381
		382	&$schedcb while @$entries && $nreq < $maxreq;
		383	};
		384	};
		385	};
		386	}
		387
214	=item aio_fsync $fh, $callback	388	=item aio_fsync $fh, $callback->($status)
215		389
216	Asynchronously call fsync on the given filehandle and call the callback	390	Asynchronously call fsync on the given filehandle and call the callback
217	with the fsync result code.	391	with the fsync result code.
218		392
219	=item aio_fdatasync $fh, $callback	393	=item aio_fdatasync $fh, $callback->($status)
220		394
221	Asynchronously call fdatasync on the given filehandle and call the	395	Asynchronously call fdatasync on the given filehandle and call the
222	callback with the fdatasync result code.	396	callback with the fdatasync result code.
223		397
224	If this call isn't available because your OS lacks it or it couldn't be	398	If this call isn't available because your OS lacks it or it couldn't be
…		…
288	IO::AIO::poll_wait, IO::AIO::poll_cb	462	IO::AIO::poll_wait, IO::AIO::poll_cb
289	if IO::AIO::nreqs;	463	if IO::AIO::nreqs;
290		464
291	=item IO::AIO::min_parallel $nthreads	465	=item IO::AIO::min_parallel $nthreads
292		466
293	Set the minimum number of AIO threads to C<$nthreads>. The default is	467	Set the minimum number of AIO threads to C<$nthreads>. The current default
294	C<1>, which means a single asynchronous operation can be done at one time	468	is C<4>, which means four asynchronous operations can be done at one time
295	(the number of outstanding operations, however, is unlimited).	469	(the number of outstanding operations, however, is unlimited).
		470
		471	IO::AIO starts threads only on demand, when an AIO request is queued and
		472	no free thread exists.
296		473
297	It is recommended to keep the number of threads low, as some Linux	474	It is recommended to keep the number of threads low, as some Linux
298	kernel versions will scale negatively with the number of threads (higher	475	kernel versions will scale negatively with the number of threads (higher
299	parallelity => MUCH higher latency). With current Linux 2.6 versions, 4-32	476	parallelity => MUCH higher latency). With current Linux 2.6 versions, 4-32
300	threads should be fine.	477	threads should be fine.
301		478
302	Under normal circumstances you don't need to call this function, as this	479	Under most circumstances you don't need to call this function, as the
303	module automatically starts some threads (the exact number might change,	480	module selects a default that is suitable for low to moderate load.
304	and is currently 4).
305		481
306	=item IO::AIO::max_parallel $nthreads	482	=item IO::AIO::max_parallel $nthreads
307		483
308	Sets the maximum number of AIO threads to C<$nthreads>. If more than	484	Sets the maximum number of AIO threads to C<$nthreads>. If more than the
309	the specified number of threads are currently running, kill them. This	485	specified number of threads are currently running, this function kills
310	function blocks until the limit is reached.	486	them. This function blocks until the limit is reached.
		487
		488	While C<$nthreads> are zero, aio requests get queued but not executed
		489	until the number of threads has been increased again.
311		490
312	This module automatically runs C<max_parallel 0> at program end, to ensure	491	This module automatically runs C<max_parallel 0> at program end, to ensure
313	that all threads are killed and that there are no outstanding requests.	492	that all threads are killed and that there are no outstanding requests.
314		493
315	Under normal circumstances you don't need to call this function.	494	Under normal circumstances you don't need to call this function.
…		…
319	Sets the maximum number of outstanding requests to C<$nreqs>. If you	498	Sets the maximum number of outstanding requests to C<$nreqs>. If you
320	try to queue up more than this number of requests, the caller will block until	499	try to queue up more than this number of requests, the caller will block until
321	some requests have been handled.	500	some requests have been handled.
322		501
323	The default is very large, so normally there is no practical limit. If you	502	The default is very large, so normally there is no practical limit. If you
324	queue up many requests in a loop it it often improves speed if you set	503	queue up many requests in a loop it often improves speed if you set
325	this to a relatively low number, such as C<100>.	504	this to a relatively low number, such as C<100>.
326		505
327	Under normal circumstances you don't need to call this function.	506	Under normal circumstances you don't need to call this function.
328		507
329	=back	508	=back
…		…
354		533
355	1;	534	1;
356		535
357	=head2 FORK BEHAVIOUR	536	=head2 FORK BEHAVIOUR
358		537
359	Before the fork IO::AIO enters a quiescent state where no requests can be	538	Before the fork, IO::AIO enters a quiescent state where no requests
360	added in other threads and no results will be processed. After the fork	539	can be added in other threads and no results will be processed. After
361	the parent simply leaves the quiescent state and continues request/result	540	the fork the parent simply leaves the quiescent state and continues
362	processing, while the child clears the request/result queue and starts the	541	request/result processing, while the child clears the request/result
363	same number of threads as were in use by the parent.	542	queue (so the requests started before the fork will only be handled in
		543	the parent). Threats will be started on demand until the limit ste in the
		544	parent process has been reached again.
364		545
365	=head1 SEE ALSO	546	=head1 SEE ALSO
366		547
367	L<Coro>, L<Linux::AIO>.	548	L<Coro>, L<Linux::AIO>.
368		549

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Comparing IO-AIO/AIO.pm (file contents): Revision 1.32 by root, Wed Aug 17 05:26:20 2005 UTC vs. Revision 1.47 by root, Thu Dec 29 15:44:13 2005 UTC

Diff Legend

Comparing IO-AIO/AIO.pm (file contents):
Revision 1.32 by root, Wed Aug 17 05:26:20 2005 UTC vs.
Revision 1.47 by root, Thu Dec 29 15:44:13 2005 UTC