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

Comparing IO-AIO/AIO.pm (file contents):
Revision 1.30 by root, Wed Aug 17 04:47:38 2005 UTC vs.
Revision 1.51 by root, Sat Jun 24 19:14:04 2006 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);
…		…
57	=cut	61	=cut
58		62
59	package IO::AIO;	63	package IO::AIO;
60		64
61	no warnings;	65	no warnings;
		66	use strict 'vars';
62		67
63	use base 'Exporter';	68	use base 'Exporter';
64		69
65	use Fcntl ();
66
67	BEGIN {	70	BEGIN {
68	$VERSION = 1.2;	71	our $VERSION = '1.8';
69		72
70	@EXPORT = qw(aio_read aio_write aio_open aio_close aio_stat aio_lstat aio_unlink	73	our @EXPORT = qw(aio_sendfile aio_read aio_write aio_open aio_close aio_stat
71	aio_rmdir aio_symlink aio_fsync aio_fdatasync aio_readahead);	74	aio_lstat aio_unlink aio_rmdir aio_readdir aio_scandir aio_symlink
		75	aio_fsync aio_fdatasync aio_readahead aio_rename aio_link aio_move);
72	@EXPORT_OK = qw(poll_fileno poll_cb min_parallel max_parallel max_outstanding nreqs);	76	our @EXPORT_OK = qw(poll_fileno poll_cb min_parallel max_parallel max_outstanding nreqs);
73		77
74	require XSLoader;	78	require XSLoader;
75	XSLoader::load IO::AIO, $VERSION;	79	XSLoader::load ("IO::AIO", $VERSION);
76	}	80	}
77		81
78	=head1 FUNCTIONS	82	=head1 FUNCTIONS
79		83
80	=head2 AIO FUNCTIONS	84	=head2 AIO FUNCTIONS
…		…
103	environment, d) use Glib::filename_from_unicode on unicode filenames or e)	107	environment, d) use Glib::filename_from_unicode on unicode filenames or e)
104	use something else.	108	use something else.
105		109
106	=over 4	110	=over 4
107		111
108	=item aio_open $pathname, $flags, $mode, $callback	112	=item aio_open $pathname, $flags, $mode, $callback->($fh)
109		113
110	Asynchronously open or create a file and call the callback with a newly	114	Asynchronously open or create a file and call the callback with a newly
111	created filehandle for the file.	115	created filehandle for the file.
112		116
113	The pathname passed to C<aio_open> must be absolute. See API NOTES, above,	117	The pathname passed to C<aio_open> must be absolute. See API NOTES, above,
…		…
130	} else {	134	} else {
131	die "open failed: $!\n";	135	die "open failed: $!\n";
132	}	136	}
133	};	137	};
134		138
135	=item aio_close $fh, $callback	139	=item aio_close $fh, $callback->($status)
136		140
137	Asynchronously close a file and call the callback with the result	141	Asynchronously close a file and call the callback with the result
138	code. I<WARNING:> although accepted, you should not pass in a perl	142	code. I<WARNING:> although accepted, you should not pass in a perl
139	filehandle here, as perl will likely close the file descriptor another	143	filehandle here, as perl will likely close the file descriptor another
140	time when the filehandle is destroyed. Normally, you can safely call perls	144	time when the filehandle is destroyed. Normally, you can safely call perls
141	C<close> or just let filehandles go out of scope.	145	C<close> or just let filehandles go out of scope.
142		146
143	This is supposed to be a bug in the API, so that might change. It's	147	This is supposed to be a bug in the API, so that might change. It's
144	therefore best to avoid this function.	148	therefore best to avoid this function.
145		149
146	=item aio_read $fh,$offset,$length, $data,$dataoffset,$callback	150	=item aio_read $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
147		151
148	=item aio_write $fh,$offset,$length, $data,$dataoffset,$callback	152	=item aio_write $fh,$offset,$length, $data,$dataoffset, $callback->($retval)
149		153
150	Reads or writes C<length> bytes from the specified C<fh> and C<offset>	154	Reads or writes C<length> bytes from the specified C<fh> and C<offset>
151	into the scalar given by C<data> and offset C<dataoffset> and calls the	155	into the scalar given by C<data> and offset C<dataoffset> and calls the
152	callback without the actual number of bytes read (or -1 on error, just	156	callback without the actual number of bytes read (or -1 on error, just
153	like the syscall).	157	like the syscall).
154		158
		159	The C<$data> scalar I<MUST NOT> be modified in any way while the request
		160	is outstanding. Modifying it can result in segfaults or WW3 (if the
		161	necessary/optional hardware is installed).
		162
155	Example: Read 15 bytes at offset 7 into scalar C<$buffer>, starting at	163	Example: Read 15 bytes at offset 7 into scalar C<$buffer>, starting at
156	offset C<0> within the scalar:	164	offset C<0> within the scalar:
157		165
158	aio_read $fh, 7, 15, $buffer, 0, sub {	166	aio_read $fh, 7, 15, $buffer, 0, sub {
159	$_[0] > 0 or die "read error: $!";	167	$_[0] > 0 or die "read error: $!";
160	print "read $_[0] bytes: <$buffer>\n";	168	print "read $_[0] bytes: <$buffer>\n";
161	};	169	};
162		170
		171	=item aio_move $srcpath, $dstpath, $callback->($status)
		172
		173	[EXPERIMENTAL]
		174
		175	Try to move the I<file> (directories not supported as either source or destination)
		176	from C<$srcpath> to C<$dstpath> and call the callback with the C<0> (error) or C<-1> ok.
		177
		178	This is a composite request that tries to rename(2) the file first. If
		179	rename files with C<EXDEV>, it creates the destination file with mode 0200
		180	and copies the contents of the source file into it using C<aio_sendfile>,
		181	followed by restoring atime, mtime, access mode and uid/gid, in that
		182	order, and unlinking the C<$srcpath>.
		183
		184	If an error occurs, the partial destination file will be unlinked, if
		185	possible, except when setting atime, mtime, access mode and uid/gid, where
		186	errors are being ignored.
		187
		188	=cut
		189
		190	sub aio_move($$$) {
		191	my ($src, $dst, $cb) = @_;
		192
		193	aio_rename $src, $dst, sub {
		194	if ($_[0] && $! == EXDEV) {
		195	aio_open $src, O_RDONLY, 0, sub {
		196	if (my $src_fh = $_[0]) {
		197	my @stat = stat $src_fh;
		198
		199	aio_open $dst, O_WRONLY, 0200, sub {
		200	if (my $dst_fh = $_[0]) {
		201	aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub {
		202	close $src_fh;
		203
		204	if ($_[0] == $stat[7]) {
		205	utime $stat[8], $stat[9], $dst;
		206	chmod $stat[2] & 07777, $dst_fh;
		207	chown $stat[4], $stat[5], $dst_fh;
		208	close $dst_fh;
		209
		210	aio_unlink $src, sub {
		211	$cb->($_[0]);
		212	};
		213	} else {
		214	my $errno = $!;
		215	aio_unlink $dst, sub {
		216	$! = $errno;
		217	$cb->(-1);
		218	};
		219	}
		220	};
		221	} else {
		222	$cb->(-1);
		223	}
		224	},
		225
		226	} else {
		227	$cb->(-1);
		228	}
		229	};
		230	} else {
		231	$cb->($_[0]);
		232	}
		233	};
		234	}
		235
		236	=item aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval)
		237
		238	Tries to copy C<$length> bytes from C<$in_fh> to C<$out_fh>. It starts
		239	reading at byte offset C<$in_offset>, and starts writing at the current
		240	file offset of C<$out_fh>. Because of that, it is not safe to issue more
		241	than one C<aio_sendfile> per C<$out_fh>, as they will interfere with each
		242	other.
		243
		244	This call tries to make use of a native C<sendfile> syscall to provide
		245	zero-copy operation. For this to work, C<$out_fh> should refer to a
		246	socket, and C<$in_fh> should refer to mmap'able file.
		247
		248	If the native sendfile call fails or is not implemented, it will be
		249	emulated, so you can call C<aio_sendfile> on any type of filehandle
		250	regardless of the limitations of the operating system.
		251
		252	Please note, however, that C<aio_sendfile> can read more bytes from
		253	C<$in_fh> than are written, and there is no way to find out how many
		254	bytes have been read from C<aio_sendfile> alone, as C<aio_sendfile> only
		255	provides the number of bytes written to C<$out_fh>. Only if the result
		256	value equals C<$length> one can assume that C<$length> bytes have been
		257	read.
		258
163	=item aio_readahead $fh,$offset,$length, $callback	259	=item aio_readahead $fh,$offset,$length, $callback->($retval)
164		260
165	C<aio_readahead> populates the page cache with data from a file so that	261	C<aio_readahead> populates the page cache with data from a file so that
166	subsequent reads from that file will not block on disk I/O. The C<$offset>	262	subsequent reads from that file will not block on disk I/O. The C<$offset>
167	argument specifies the starting point from which data is to be read and	263	argument specifies the starting point from which data is to be read and
168	C<$length> specifies the number of bytes to be read. I/O is performed in	264	C<$length> specifies the number of bytes to be read. I/O is performed in
…		…
172	file. The current file offset of the file is left unchanged.	268	file. The current file offset of the file is left unchanged.
173		269
174	If that syscall doesn't exist (likely if your OS isn't Linux) it will be	270	If that syscall doesn't exist (likely if your OS isn't Linux) it will be
175	emulated by simply reading the data, which would have a similar effect.	271	emulated by simply reading the data, which would have a similar effect.
176		272
177	=item aio_stat $fh_or_path, $callback	273	=item aio_stat $fh_or_path, $callback->($status)
178		274
179	=item aio_lstat $fh, $callback	275	=item aio_lstat $fh, $callback->($status)
180		276
181	Works like perl's C<stat> or C<lstat> in void context. The callback will	277	Works like perl's C<stat> or C<lstat> in void context. The callback will
182	be called after the stat and the results will be available using C<stat _>	278	be called after the stat and the results will be available using C<stat _>
183	or C<-s _> etc...	279	or C<-s _> etc...
184		280
…		…
194	aio_stat "/etc/passwd", sub {	290	aio_stat "/etc/passwd", sub {
195	$_[0] and die "stat failed: $!";	291	$_[0] and die "stat failed: $!";
196	print "size is ", -s _, "\n";	292	print "size is ", -s _, "\n";
197	};	293	};
198		294
199	=item aio_unlink $pathname, $callback	295	=item aio_unlink $pathname, $callback->($status)
200		296
201	Asynchronously unlink (delete) a file and call the callback with the	297	Asynchronously unlink (delete) a file and call the callback with the
202	result code.	298	result code.
203		299
		300	=item aio_link $srcpath, $dstpath, $callback->($status)
		301
		302	Asynchronously create a new link to the existing object at C<$srcpath> at
		303	the path C<$dstpath> and call the callback with the result code.
		304
		305	=item aio_symlink $srcpath, $dstpath, $callback->($status)
		306
		307	Asynchronously create a new symbolic link to the existing object at C<$srcpath> at
		308	the path C<$dstpath> and call the callback with the result code.
		309
		310	=item aio_rename $srcpath, $dstpath, $callback->($status)
		311
		312	Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as
		313	rename(2) and call the callback with the result code.
		314
204	=item aio_rmdir $pathname, $callback	315	=item aio_rmdir $pathname, $callback->($status)
205		316
206	Asynchronously rmdir (delete) a directory and call the callback with the	317	Asynchronously rmdir (delete) a directory and call the callback with the
207	result code.	318	result code.
208		319
		320	=item aio_readdir $pathname, $callback->($entries)
		321
		322	Unlike the POSIX call of the same name, C<aio_readdir> reads an entire
		323	directory (i.e. opendir + readdir + closedir). The entries will not be
		324	sorted, and will B<NOT> include the C<.> and C<..> entries.
		325
		326	The callback a single argument which is either C<undef> or an array-ref
		327	with the filenames.
		328
		329	=item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs)
		330
		331	Scans a directory (similar to C<aio_readdir>) and tries to separate the
		332	entries of directory C<$path> into two sets of names, ones you can recurse
		333	into (directories), and ones you cannot recurse into (everything else).
		334
		335	C<aio_scandir> is a composite request that consists of many
		336	aio-primitives. C<$maxreq> specifies the maximum number of outstanding
		337	aio requests that this function generates. If it is C<< <= 0 >>, then a
		338	suitable default will be chosen (currently 8).
		339
		340	On error, the callback is called without arguments, otherwise it receives
		341	two array-refs with path-relative entry names.
		342
		343	Example:
		344
		345	aio_scandir $dir, 0, sub {
		346	my ($dirs, $nondirs) = @_;
		347	print "real directories: @$dirs\n";
		348	print "everything else: @$nondirs\n";
		349	};
		350
		351	Implementation notes.
		352
		353	The C<aio_readdir> cannot be avoided, but C<stat()>'ing every entry can.
		354
		355	After reading the directory, the modification time, size etc. of the
		356	directory before and after the readdir is checked, and if they match, the
		357	link count will be used to decide how many entries are directories (if
		358	>= 2). Otherwise, no knowledge of the number of subdirectories will be
		359	assumed.
		360
		361	Then entires will be sorted into likely directories (everything without a
		362	non-initial dot) and likely non-directories (everything else). Then every
		363	entry + C</.> will be C<stat>'ed, likely directories first. This is often
		364	faster because filesystems might detect the type of the entry without
		365	reading the inode data (e.g. ext2fs filetype feature). If that succeeds,
		366	it assumes that the entry is a directory or a symlink to directory (which
		367	will be checked seperately).
		368
		369	If the known number of directories has been reached, the rest of the
		370	entries is assumed to be non-directories.
		371
		372	=cut
		373
		374	sub aio_scandir($$$) {
		375	my ($path, $maxreq, $cb) = @_;
		376
		377	$maxreq = 8 if $maxreq <= 0;
		378
		379	# stat once
		380	aio_stat $path, sub {
		381	return $cb->() if $_[0];
		382	my $hash1 = join ":", (stat _)[0,1,3,7,9];
		383
		384	# read the directory entries
		385	aio_readdir $path, sub {
		386	my $entries = shift
		387	or return $cb->();
		388
		389	# stat the dir another time
		390	aio_stat $path, sub {
		391	my $hash2 = join ":", (stat _)[0,1,3,7,9];
		392
		393	my $ndirs;
		394
		395	# take the slow route if anything looks fishy
		396	if ($hash1 ne $hash2) {
		397	$ndirs = -1;
		398	} else {
		399	# if nlink == 2, we are finished
		400	# on non-posix-fs's, we rely on nlink < 2
		401	$ndirs = (stat _)[3] - 2
		402	or return $cb->([], $entries);
		403	}
		404
		405	# sort into likely dirs and likely nondirs
		406	# dirs == files without ".", short entries first
		407	$entries = [map $_->[0],
		408	sort { $b->[1] cmp $a->[1] }
		409	map [$_, sprintf "%s%04d", (/.\./ ? "1" : "0"), length],
		410	@$entries];
		411
		412	my (@dirs, @nondirs);
		413
		414	my ($statcb, $schedcb);
		415	my $nreq = 0;
		416
		417	$schedcb = sub {
		418	if (@$entries) {
		419	if ($nreq < $maxreq) {
		420	my $ent = pop @$entries;
		421	$nreq++;
		422	aio_stat "$path/$ent/.", sub { $statcb->($_[0], $ent) };
		423	}
		424	} elsif (!$nreq) {
		425	# finished
		426	undef $statcb;
		427	undef $schedcb;
		428	$cb->(\@dirs, \@nondirs) if $cb;
		429	undef $cb;
		430	}
		431	};
		432	$statcb = sub {
		433	my ($status, $entry) = @_;
		434
		435	if ($status < 0) {
		436	$nreq--;
		437	push @nondirs, $entry;
		438	&$schedcb;
		439	} else {
		440	# need to check for real directory
		441	aio_lstat "$path/$entry", sub {
		442	$nreq--;
		443
		444	if (-d _) {
		445	push @dirs, $entry;
		446
		447	if (!--$ndirs) {
		448	push @nondirs, @$entries;
		449	$entries = [];
		450	}
		451	} else {
		452	push @nondirs, $entry;
		453	}
		454
		455	&$schedcb;
		456	}
		457	}
		458	};
		459
		460	&$schedcb while @$entries && $nreq < $maxreq;
		461	};
		462	};
		463	};
		464	}
		465
209	=item aio_fsync $fh, $callback	466	=item aio_fsync $fh, $callback->($status)
210		467
211	Asynchronously call fsync on the given filehandle and call the callback	468	Asynchronously call fsync on the given filehandle and call the callback
212	with the fsync result code.	469	with the fsync result code.
213		470
214	=item aio_fdatasync $fh, $callback	471	=item aio_fdatasync $fh, $callback->($status)
215		472
216	Asynchronously call fdatasync on the given filehandle and call the	473	Asynchronously call fdatasync on the given filehandle and call the
217	callback with the fdatasync result code.	474	callback with the fdatasync result code.
218		475
219	If this call isn't available because your OS lacks it or it couldn't be	476	If this call isn't available because your OS lacks it or it couldn't be
…		…
283	IO::AIO::poll_wait, IO::AIO::poll_cb	540	IO::AIO::poll_wait, IO::AIO::poll_cb
284	if IO::AIO::nreqs;	541	if IO::AIO::nreqs;
285		542
286	=item IO::AIO::min_parallel $nthreads	543	=item IO::AIO::min_parallel $nthreads
287		544
288	Set the minimum number of AIO threads to C<$nthreads>. The default is	545	Set the minimum number of AIO threads to C<$nthreads>. The current default
289	C<1>, which means a single asynchronous operation can be done at one time	546	is C<4>, which means four asynchronous operations can be done at one time
290	(the number of outstanding operations, however, is unlimited).	547	(the number of outstanding operations, however, is unlimited).
		548
		549	IO::AIO starts threads only on demand, when an AIO request is queued and
		550	no free thread exists.
291		551
292	It is recommended to keep the number of threads low, as some Linux	552	It is recommended to keep the number of threads low, as some Linux
293	kernel versions will scale negatively with the number of threads (higher	553	kernel versions will scale negatively with the number of threads (higher
294	parallelity => MUCH higher latency). With current Linux 2.6 versions, 4-32	554	parallelity => MUCH higher latency). With current Linux 2.6 versions, 4-32
295	threads should be fine.	555	threads should be fine.
296		556
297	Under normal circumstances you don't need to call this function, as this	557	Under most circumstances you don't need to call this function, as the
298	module automatically starts some threads (the exact number might change,	558	module selects a default that is suitable for low to moderate load.
299	and is currently 4).
300		559
301	=item IO::AIO::max_parallel $nthreads	560	=item IO::AIO::max_parallel $nthreads
302		561
303	Sets the maximum number of AIO threads to C<$nthreads>. If more than	562	Sets the maximum number of AIO threads to C<$nthreads>. If more than the
304	the specified number of threads are currently running, kill them. This	563	specified number of threads are currently running, this function kills
305	function blocks until the limit is reached.	564	them. This function blocks until the limit is reached.
		565
		566	While C<$nthreads> are zero, aio requests get queued but not executed
		567	until the number of threads has been increased again.
306		568
307	This module automatically runs C<max_parallel 0> at program end, to ensure	569	This module automatically runs C<max_parallel 0> at program end, to ensure
308	that all threads are killed and that there are no outstanding requests.	570	that all threads are killed and that there are no outstanding requests.
309		571
310	Under normal circumstances you don't need to call this function.	572	Under normal circumstances you don't need to call this function.
…		…
314	Sets the maximum number of outstanding requests to C<$nreqs>. If you	576	Sets the maximum number of outstanding requests to C<$nreqs>. If you
315	try to queue up more than this number of requests, the caller will block until	577	try to queue up more than this number of requests, the caller will block until
316	some requests have been handled.	578	some requests have been handled.
317		579
318	The default is very large, so normally there is no practical limit. If you	580	The default is very large, so normally there is no practical limit. If you
319	queue up many requests in a loop it it often improves speed if you set	581	queue up many requests in a loop it often improves speed if you set
320	this to a relatively low number, such as C<100>.	582	this to a relatively low number, such as C<100>.
321		583
322	Under normal circumstances you don't need to call this function.	584	Under normal circumstances you don't need to call this function.
323		585
324	=back	586	=back
…		…
349		611
350	1;	612	1;
351		613
352	=head2 FORK BEHAVIOUR	614	=head2 FORK BEHAVIOUR
353		615
354	Before the fork IO::AIO first handles all outstanding requests - if other	616	Before the fork, IO::AIO enters a quiescent state where no requests
355	threads add requests during this period, this time is prolonged. It then	617	can be added in other threads and no results will be processed. After
356	enters a quiescent state where no requests can be added in other threads	618	the fork the parent simply leaves the quiescent state and continues
357	and no results will be processed. After the fork the parent simply leaves	619	request/result processing, while the child clears the request/result
358	the quiescent state and continues request processing, while the child	620	queue (so the requests started before the fork will only be handled in
359	starts the same number of threads as were in use by the parent.	621	the parent). Threats will be started on demand until the limit ste in the
		622	parent process has been reached again.
360		623
361	=head1 SEE ALSO	624	=head1 SEE ALSO
362		625
363	L<Coro>, L<Linux::AIO>.	626	L<Coro>, L<Linux::AIO>.
364		627

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Comparing IO-AIO/AIO.pm (file contents): Revision 1.30 by root, Wed Aug 17 04:47:38 2005 UTC vs. Revision 1.51 by root, Sat Jun 24 19:14:04 2006 UTC

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Comparing IO-AIO/AIO.pm (file contents):
Revision 1.30 by root, Wed Aug 17 04:47:38 2005 UTC vs.
Revision 1.51 by root, Sat Jun 24 19:14:04 2006 UTC