[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 1.40 by root, Tue Aug 30 15:45:10 2005 UTC

…		…
63	use base 'Exporter';	63	use base 'Exporter';
64		64
65	use Fcntl ();	65	use Fcntl ();
66		66
67	BEGIN {	67	BEGIN {
68	$VERSION = 1.3;	68	$VERSION = 1.6;
69		69
70
71	@EXPORT = qw(aio_read aio_write aio_open aio_close aio_stat aio_lstat aio_unlink	70	@EXPORT = qw(aio_sendfile aio_read aio_write aio_open aio_close aio_stat
		71	aio_lstat aio_unlink aio_rmdir aio_readdir aio_scandir aio_symlink
72	aio_rmdir aio_symlink aio_fsync aio_fdatasync aio_readahead);	72	aio_fsync aio_fdatasync aio_readahead);
73	@EXPORT_OK = qw(poll_fileno poll_cb min_parallel max_parallel max_outstanding nreqs);	73	@EXPORT_OK = qw(poll_fileno poll_cb min_parallel max_parallel
		74	max_outstanding nreqs);
74		75
75	require XSLoader;	76	require XSLoader;
76	XSLoader::load IO::AIO, $VERSION;	77	XSLoader::load IO::AIO, $VERSION;
77	}	78	}
78		79
…		…
104	environment, d) use Glib::filename_from_unicode on unicode filenames or e)	105	environment, d) use Glib::filename_from_unicode on unicode filenames or e)
105	use something else.	106	use something else.
106		107
107	=over 4	108	=over 4
108		109
109	=item aio_open $pathname, $flags, $mode, $callback	110	=item aio_open $pathname, $flags, $mode, $callback->($fh)
110		111
111	Asynchronously open or create a file and call the callback with a newly	112	Asynchronously open or create a file and call the callback with a newly
112	created filehandle for the file.	113	created filehandle for the file.
113		114
114	The pathname passed to C<aio_open> must be absolute. See API NOTES, above,	115	The pathname passed to C<aio_open> must be absolute. See API NOTES, above,
…		…
131	} else {	132	} else {
132	die "open failed: $!\n";	133	die "open failed: $!\n";
133	}	134	}
134	};	135	};
135		136
136	=item aio_close $fh, $callback	137	=item aio_close $fh, $callback->($status)
137		138
138	Asynchronously close a file and call the callback with the result	139	Asynchronously close a file and call the callback with the result
139	code. I<WARNING:> although accepted, you should not pass in a perl	140	code. I<WARNING:> although accepted, you should not pass in a perl
140	filehandle here, as perl will likely close the file descriptor another	141	filehandle here, as perl will likely close the file descriptor another
141	time when the filehandle is destroyed. Normally, you can safely call perls	142	time when the filehandle is destroyed. Normally, you can safely call perls
142	C<close> or just let filehandles go out of scope.	143	C<close> or just let filehandles go out of scope.
143		144
144	This is supposed to be a bug in the API, so that might change. It's	145	This is supposed to be a bug in the API, so that might change. It's
145	therefore best to avoid this function.	146	therefore best to avoid this function.
146		147
147	=item aio_read $fh,$offset,$length, $data,$dataoffset,$callback	148	=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
148		149
149	=item aio_write $fh,$offset,$length, $data,$dataoffset,$callback	150	=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
150		151
151	Reads or writes C<length> bytes from the specified C<fh> and C<offset>	152	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	153	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	154	callback without the actual number of bytes read (or -1 on error, just
154	like the syscall).	155	like the syscall).
…		…
163	aio_read $fh, 7, 15, $buffer, 0, sub {	164	aio_read $fh, 7, 15, $buffer, 0, sub {
164	$_[0] > 0 or die "read error: $!";	165	$_[0] > 0 or die "read error: $!";
165	print "read $_[0] bytes: <$buffer>\n";	166	print "read $_[0] bytes: <$buffer>\n";
166	};	167	};
167		168
		169	=item aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval)
		170
		171	Tries to copy C<$length> bytes from C<$in_fh> to C<$out_fh>. It starts
		172	reading at byte offset C<$in_offset>, and starts writing at the current
		173	file offset of C<$out_fh>. Because of that, it is not safe to issue more
		174	than one C<aio_sendfile> per C<$out_fh>, as they will interfere with each
		175	other.
		176
		177	This call tries to make use of a native C<sendfile> syscall to provide
		178	zero-copy operation. For this to work, C<$out_fh> should refer to a
		179	socket, and C<$in_fh> should refer to mmap'able file.
		180
		181	If the native sendfile call fails or is not implemented, it will be
		182	emulated, so you can call C<aio_sendfile> on any type of filehandle
		183	regardless of the limitations of the operating system.
		184
		185	Please note, however, that C<aio_sendfile> can read more bytes from
		186	C<$in_fh> than are written, and there is no way to find out how many
		187	bytes have been read from C<aio_sendfile> alone, as C<aio_sendfile> only
		188	provides the number of bytes written to C<$out_fh>. Only if the result
		189	value equals C<$length> one can assume that C<$length> bytes have been
		190	read.
		191
168	=item aio_readahead $fh,$offset,$length, $callback	192	=item aio_readahead $fh,$offset,$length, $callback->($retval)
169		193
170	C<aio_readahead> populates the page cache with data from a file so that	194	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<$offset>	195	subsequent reads from that file will not block on disk I/O. The C<$offset>
172	argument specifies the starting point from which data is to be read and	196	argument specifies the starting point from which data is to be read and
173	C<$length> specifies the number of bytes to be read. I/O is performed in	197	C<$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.	201	file. The current file offset of the file is left unchanged.
178		202
179	If that syscall doesn't exist (likely if your OS isn't Linux) it will be	203	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.	204	emulated by simply reading the data, which would have a similar effect.
181		205
182	=item aio_stat $fh_or_path, $callback	206	=item aio_stat $fh_or_path, $callback->($status)
183		207
184	=item aio_lstat $fh, $callback	208	=item aio_lstat $fh, $callback->($status)
185		209
186	Works like perl's C<stat> or C<lstat> in void context. The callback will	210	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 _>	211	be called after the stat and the results will be available using C<stat _>
188	or C<-s _> etc...	212	or C<-s _> etc...
189		213
…		…
199	aio_stat "/etc/passwd", sub {	223	aio_stat "/etc/passwd", sub {
200	$_[0] and die "stat failed: $!";	224	$_[0] and die "stat failed: $!";
201	print "size is ", -s _, "\n";	225	print "size is ", -s _, "\n";
202	};	226	};
203		227
204	=item aio_unlink $pathname, $callback	228	=item aio_unlink $pathname, $callback->($status)
205		229
206	Asynchronously unlink (delete) a file and call the callback with the	230	Asynchronously unlink (delete) a file and call the callback with the
207	result code.	231	result code.
208		232
209	=item aio_rmdir $pathname, $callback	233	=item aio_rmdir $pathname, $callback->($status)
210		234
211	Asynchronously rmdir (delete) a directory and call the callback with the	235	Asynchronously rmdir (delete) a directory and call the callback with the
212	result code.	236	result code.
213		237
		238	=item aio_readdir $pathname $callback->($entries)
		239
		240	Unlike the POSIX call of the same name, C<aio_readdir> reads an entire
		241	directory (i.e. opendir + readdir + closedir). The entries will not be
		242	sorted, and will B<NOT> include the C<.> and C<..> entries.
		243
		244	The callback a single argument which is either C<undef> or an array-ref
		245	with the filenames.
		246
		247	=item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs)
		248
		249	Scans a directory (similar to C<aio_readdir>) and tries to separate the
		250	entries of directory C<$path> into two sets of names, ones you can recurse
		251	into (directories), and ones you cannot recurse into (everything else).
		252
		253	C<aio_scandir> is a composite request that consists of many
		254	aio-primitives. C<$maxreq> specifies the maximum number of outstanding
		255	aio requests that this function generates. If it is C<< <= 0 >>, then a
		256	suitable default will be chosen (currently 8).
		257
		258	On error, the callback is called without arguments, otherwise it receives
		259	two array-refs with path-relative entry names.
		260
		261	Example:
		262
		263	aio_scandir $dir, 0, sub {
		264	my ($dirs, $nondirs) = @_;
		265	print "real directories: @$dirs\n";
		266	print "everything else: @$nondirs\n";
		267	};
		268
		269	Implementation notes.
		270
		271	The C<aio_readdir> cannot be avoided, but C<stat()>'ing every entry can.
		272
		273	After reading the directory, the modification time, size etc. of the
		274	directory before and after the readdir is checked, and if they match, the
		275	link count will be used to decide how many entries are directories (if
		276	>= 2). Otherwise, no knowledge of the number of subdirectories will be
		277	assumed.
		278
		279	Then entires will be sorted into likely directories (everything without a
		280	non-initial dot) and likely non-directories (everything else). Then every
		281	entry + C</.> will be C<stat>'ed, likely directories first. This is often
		282	faster because filesystems might detect the type of the entry without
		283	reading the inode data (e.g. ext2s filetype feature). If that succeeds,
		284	it assumes that the entry is a directory or a symlink to directory (which
		285	will be checked seperately).
		286
		287	If the known number of directories has been reached, the rest of the
		288	entries is assumed to be non-directories.
		289
		290	=cut
		291
		292	sub aio_scandir($$$) {
		293	my ($path, $maxreq, $cb) = @_;
		294
		295	$maxreq = 8 if $maxreq <= 0;
		296
		297	# stat once
		298	aio_stat $path, sub {
		299	$cb->() if $_[0];
		300	my $hash1 = join ":", (stat _)[0,1,3,7,9];
		301
		302	# read the directory entries
		303	aio_readdir $path, sub {
		304	my $entries = shift
		305	or return $cb->();
		306
		307	# stat the dir another time
		308	aio_stat $path, sub {
		309	my $hash2 = join ":", (stat _)[0,1,3,7,9];
		310
		311	my $ndirs;
		312
		313	# take the slow route if anything looks fishy
		314	if ($hash1 ne $hash2) {
		315	$ndirs = -1;
		316	} else {
		317	# if nlink == 2, we are finished
		318	# on non-posix-fs's, we rely on nlink < 2
		319	$ndirs = (stat _)[3] - 2
		320	or $cb->([], $entries);
		321	}
		322
		323	# sort into likely dirs and likely nondirs
		324	# dirs == files without ".", short entries first
		325	$entries = [map $_->[0],
		326	sort { $b->[1] cmp $a->[1] }
		327	map [$_, sprintf "%s%04d", (/.\./ ? "1" : "0"), length],
		328	@$entries];
		329
		330	my (@dirs, @nondirs);
		331
		332	my ($statcb, $schedcb);
		333	my $nreq = 0;
		334
		335	$schedcb = sub {
		336	if (@$entries) {
		337	if ($nreq < $maxreq) {
		338	my $ent = pop @$entries;
		339	$nreq++;
		340	aio_stat "$path/$ent/.", sub { $statcb->($_[0], $ent) };
		341	}
		342	} elsif (!$nreq) {
		343	# finished
		344	undef $statcb;
		345	undef $schedcb;
		346	$cb->(\@dirs, \@nondirs);
		347	undef $cb;
		348	}
		349	};
		350	$statcb = sub {
		351	my ($status, $entry) = @_;
		352
		353	if ($status < 0) {
		354	$nreq--;
		355	push @nondirs, $entry;
		356	&$schedcb;
		357	} else {
		358	# need to check for real directory
		359	aio_lstat "$path/$entry", sub {
		360	$nreq--;
		361
		362	if (-d _) {
		363	push @dirs, $entry;
		364
		365	if (!--$ndirs) {
		366	push @nondirs, @$entries;
		367	$entries = [];
		368	}
		369	} else {
		370	push @nondirs, $entry;
		371	}
		372
		373	&$schedcb;
		374	}
		375	}
		376	};
		377
		378	&$schedcb while @$entries && $nreq < $maxreq;
		379	};
		380	};
		381	};
		382	}
		383
214	=item aio_fsync $fh, $callback	384	=item aio_fsync $fh, $callback->($status)
215		385
216	Asynchronously call fsync on the given filehandle and call the callback	386	Asynchronously call fsync on the given filehandle and call the callback
217	with the fsync result code.	387	with the fsync result code.
218		388
219	=item aio_fdatasync $fh, $callback	389	=item aio_fdatasync $fh, $callback->($status)
220		390
221	Asynchronously call fdatasync on the given filehandle and call the	391	Asynchronously call fdatasync on the given filehandle and call the
222	callback with the fdatasync result code.	392	callback with the fdatasync result code.
223		393
224	If this call isn't available because your OS lacks it or it couldn't be	394	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	458	IO::AIO::poll_wait, IO::AIO::poll_cb
289	if IO::AIO::nreqs;	459	if IO::AIO::nreqs;
290		460
291	=item IO::AIO::min_parallel $nthreads	461	=item IO::AIO::min_parallel $nthreads
292		462
293	Set the minimum number of AIO threads to C<$nthreads>. The default is	463	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	464	is C<4>, which means four asynchronous operations can be done at one time
295	(the number of outstanding operations, however, is unlimited).	465	(the number of outstanding operations, however, is unlimited).
		466
		467	IO::AIO starts threads only on demand, when an AIO request is queued and
		468	no free thread exists.
296		469
297	It is recommended to keep the number of threads low, as some Linux	470	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	471	kernel versions will scale negatively with the number of threads (higher
299	parallelity => MUCH higher latency). With current Linux 2.6 versions, 4-32	472	parallelity => MUCH higher latency). With current Linux 2.6 versions, 4-32
300	threads should be fine.	473	threads should be fine.
301		474
302	Under normal circumstances you don't need to call this function, as this	475	Under most circumstances you don't need to call this function, as the
303	module automatically starts some threads (the exact number might change,	476	module selects a default that is suitable for low to moderate load.
304	and is currently 4).
305		477
306	=item IO::AIO::max_parallel $nthreads	478	=item IO::AIO::max_parallel $nthreads
307		479
308	Sets the maximum number of AIO threads to C<$nthreads>. If more than	480	Sets the maximum number of AIO threads to C<$nthreads>. If more than the
309	the specified number of threads are currently running, kill them. This	481	specified number of threads are currently running, this function kills
310	function blocks until the limit is reached.	482	them. This function blocks until the limit is reached.
		483
		484	While C<$nthreads> are zero, aio requests get queued but not executed
		485	until the number of threads has been increased again.
311		486
312	This module automatically runs C<max_parallel 0> at program end, to ensure	487	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.	488	that all threads are killed and that there are no outstanding requests.
314		489
315	Under normal circumstances you don't need to call this function.	490	Under normal circumstances you don't need to call this function.
…		…
319	Sets the maximum number of outstanding requests to C<$nreqs>. If you	494	Sets the maximum number of outstanding requests to C<$nreqs>. If you
320	try to queue up more than this number of requests, the caller will block until	495	try to queue up more than this number of requests, the caller will block until
321	some requests have been handled.	496	some requests have been handled.
322		497
323	The default is very large, so normally there is no practical limit. If you	498	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	499	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>.	500	this to a relatively low number, such as C<100>.
326		501
327	Under normal circumstances you don't need to call this function.	502	Under normal circumstances you don't need to call this function.
328		503
329	=back	504	=back
…		…
354		529
355	1;	530	1;
356		531
357	=head2 FORK BEHAVIOUR	532	=head2 FORK BEHAVIOUR
358		533
359	Before the fork IO::AIO enters a quiescent state where no requests can be	534	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	535	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	536	the fork the parent simply leaves the quiescent state and continues
362	processing, while the child clears the request/result queue and starts the	537	request/result processing, while the child clears the request/result
363	same number of threads as were in use by the parent.	538	queue (so the requests started before the fork will only be handled in
		539	the parent). Threats will be started on demand until the limit ste in the
		540	parent process has been reached again.
364		541
365	=head1 SEE ALSO	542	=head1 SEE ALSO
366		543
367	L<Coro>, L<Linux::AIO>.	544	L<Coro>, L<Linux::AIO>.
368		545

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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 1.40 by root, Tue Aug 30 15:45:10 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 1.40 by root, Tue Aug 30 15:45:10 2005 UTC