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

Comparing IO-AIO/AIO.pm (file contents):
Revision 1.40 by root, Tue Aug 30 15:45:10 2005 UTC vs.
Revision 1.55 by root, Sun Oct 22 00:49:29 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	use IO::AIO 2; # version has aio objects
		21
		22	my $req = aio_unlink "/tmp/file", sub { };
		23	$req->cancel; # cancel request if still in queue
		24
		25	# AnyEvent
		26	open my $fh, "<&=" . IO::AIO::poll_fileno or die "$!";
		27	my $w = AnyEvent->io (fh => $fh, poll => 'r', cb => sub { IO::AIO::poll_cb });
19		28
20	# Event	29	# Event
21	Event->io (fd => IO::AIO::poll_fileno,	30	Event->io (fd => IO::AIO::poll_fileno,
22	poll => 'r',	31	poll => 'r',
23	cb => \&IO::AIO::poll_cb);	32	cb => \&IO::AIO::poll_cb);
…		…
57	=cut	66	=cut
58		67
59	package IO::AIO;	68	package IO::AIO;
60		69
61	no warnings;	70	no warnings;
		71	use strict 'vars';
62		72
63	use base 'Exporter';	73	use base 'Exporter';
64		74
65	use Fcntl ();
66
67	BEGIN {	75	BEGIN {
68	$VERSION = 1.6;	76	our $VERSION = '2.0';
69		77
70	@EXPORT = qw(aio_sendfile aio_read aio_write aio_open aio_close aio_stat	78	our @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	79	aio_lstat aio_unlink aio_rmdir aio_readdir aio_scandir aio_symlink
72	aio_fsync aio_fdatasync aio_readahead);	80	aio_fsync aio_fdatasync aio_readahead aio_rename aio_link aio_move
		81	aio_group);
73	@EXPORT_OK = qw(poll_fileno poll_cb min_parallel max_parallel	82	our @EXPORT_OK = qw(poll_fileno poll_cb min_parallel max_parallel max_outstanding nreqs);
74	max_outstanding nreqs);	83
		84	@IO::AIO::GRP::ISA = 'IO::AIO::REQ';
75		85
76	require XSLoader;	86	require XSLoader;
77	XSLoader::load IO::AIO, $VERSION;	87	XSLoader::load ("IO::AIO", $VERSION);
78	}	88	}
79		89
80	=head1 FUNCTIONS	90	=head1 FUNCTIONS
81		91
82	=head2 AIO FUNCTIONS	92	=head2 AIO FUNCTIONS
…		…
89	perl, which usually delivers "false") as it's sole argument when the given	99	perl, which usually delivers "false") as it's sole argument when the given
90	syscall has been executed asynchronously.	100	syscall has been executed asynchronously.
91		101
92	All functions expecting a filehandle keep a copy of the filehandle	102	All functions expecting a filehandle keep a copy of the filehandle
93	internally until the request has finished.	103	internally until the request has finished.
		104
		105	All requests return objects of type L<IO::AIO::REQ> that allow further
		106	manipulation of those requests while they are in-flight.
94		107
95	The pathnames you pass to these routines I<must> be absolute and	108	The pathnames you pass to these routines I<must> be absolute and
96	encoded in byte form. The reason for the former is that at the time the	109	encoded in byte form. The reason for the former is that at the time the
97	request is being executed, the current working directory could have	110	request is being executed, the current working directory could have
98	changed. Alternatively, you can make sure that you never change the	111	changed. Alternatively, you can make sure that you never change the
…		…
164	aio_read $fh, 7, 15, $buffer, 0, sub {	177	aio_read $fh, 7, 15, $buffer, 0, sub {
165	$_[0] > 0 or die "read error: $!";	178	$_[0] > 0 or die "read error: $!";
166	print "read $_[0] bytes: <$buffer>\n";	179	print "read $_[0] bytes: <$buffer>\n";
167	};	180	};
168		181
		182	=item aio_move $srcpath, $dstpath, $callback->($status)
		183
		184	Try to move the I<file> (directories not supported as either source or
		185	destination) from C<$srcpath> to C<$dstpath> and call the callback with
		186	the C<0> (error) or C<-1> ok.
		187
		188	This is a composite request that tries to rename(2) the file first. If
		189	rename files with C<EXDEV>, it creates the destination file with mode 0200
		190	and copies the contents of the source file into it using C<aio_sendfile>,
		191	followed by restoring atime, mtime, access mode and uid/gid, in that
		192	order, and unlinking the C<$srcpath>.
		193
		194	If an error occurs, the partial destination file will be unlinked, if
		195	possible, except when setting atime, mtime, access mode and uid/gid, where
		196	errors are being ignored.
		197
		198	=cut
		199
		200	sub aio_move($$$) {
		201	my ($src, $dst, $cb) = @_;
		202
		203	my $grp = aio_group;
		204
		205	add $grp aio_rename $src, $dst, sub {
		206	if ($_[0] && $! == EXDEV) {
		207	add $grp aio_open $src, O_RDONLY, 0, sub {
		208	if (my $src_fh = $_[0]) {
		209	my @stat = stat $src_fh;
		210
		211	add $grp aio_open $dst, O_WRONLY, 0200, sub {
		212	if (my $dst_fh = $_[0]) {
		213	add $grp aio_sendfile $dst_fh, $src_fh, 0, $stat[7], sub {
		214	close $src_fh;
		215
		216	if ($_[0] == $stat[7]) {
		217	utime $stat[8], $stat[9], $dst;
		218	chmod $stat[2] & 07777, $dst_fh;
		219	chown $stat[4], $stat[5], $dst_fh;
		220	close $dst_fh;
		221
		222	add $grp aio_unlink $src, sub {
		223	$cb->($_[0]);
		224	};
		225	} else {
		226	my $errno = $!;
		227	add $grp aio_unlink $dst, sub {
		228	$! = $errno;
		229	$cb->(-1);
		230	};
		231	}
		232	};
		233	} else {
		234	$cb->(-1);
		235	}
		236	},
		237
		238	} else {
		239	$cb->(-1);
		240	}
		241	};
		242	} else {
		243	$cb->($_[0]);
		244	}
		245	};
		246
		247	$grp
		248	}
		249
169	=item aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval)	250	=item aio_sendfile $out_fh, $in_fh, $in_offset, $length, $callback->($retval)
170		251
171	Tries to copy C<$length> bytes from C<$in_fh> to C<$out_fh>. It starts	252	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	253	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	254	file offset of C<$out_fh>. Because of that, it is not safe to issue more
…		…
228	=item aio_unlink $pathname, $callback->($status)	309	=item aio_unlink $pathname, $callback->($status)
229		310
230	Asynchronously unlink (delete) a file and call the callback with the	311	Asynchronously unlink (delete) a file and call the callback with the
231	result code.	312	result code.
232		313
		314	=item aio_link $srcpath, $dstpath, $callback->($status)
		315
		316	Asynchronously create a new link to the existing object at C<$srcpath> at
		317	the path C<$dstpath> and call the callback with the result code.
		318
		319	=item aio_symlink $srcpath, $dstpath, $callback->($status)
		320
		321	Asynchronously create a new symbolic link to the existing object at C<$srcpath> at
		322	the path C<$dstpath> and call the callback with the result code.
		323
		324	=item aio_rename $srcpath, $dstpath, $callback->($status)
		325
		326	Asynchronously rename the object at C<$srcpath> to C<$dstpath>, just as
		327	rename(2) and call the callback with the result code.
		328
233	=item aio_rmdir $pathname, $callback->($status)	329	=item aio_rmdir $pathname, $callback->($status)
234		330
235	Asynchronously rmdir (delete) a directory and call the callback with the	331	Asynchronously rmdir (delete) a directory and call the callback with the
236	result code.	332	result code.
237		333
238	=item aio_readdir $pathname $callback->($entries)	334	=item aio_readdir $pathname, $callback->($entries)
239		335
240	Unlike the POSIX call of the same name, C<aio_readdir> reads an entire	336	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	337	directory (i.e. opendir + readdir + closedir). The entries will not be
242	sorted, and will B<NOT> include the C<.> and C<..> entries.	338	sorted, and will B<NOT> include the C<.> and C<..> entries.
243		339
244	The callback a single argument which is either C<undef> or an array-ref	340	The callback a single argument which is either C<undef> or an array-ref
245	with the filenames.	341	with the filenames.
246		342
247	=item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs)	343	=item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs)
248		344
249	Scans a directory (similar to C<aio_readdir>) and tries to separate the	345	Scans a directory (similar to C<aio_readdir>) but additionally tries to
250	entries of directory C<$path> into two sets of names, ones you can recurse	346	separate the entries of directory C<$path> into two sets of names, ones
251	into (directories), and ones you cannot recurse into (everything else).	347	you can recurse into (directories or links to them), and ones you cannot
		348	recurse into (everything else).
252		349
253	C<aio_scandir> is a composite request that consists of many	350	C<aio_scandir> is a composite request that consists of many sub
254	aio-primitives. C<$maxreq> specifies the maximum number of outstanding	351	requests. C<$maxreq> specifies the maximum number of outstanding aio
255	aio requests that this function generates. If it is C<< <= 0 >>, then a	352	requests that this function generates. If it is C<< <= 0 >>, then a
256	suitable default will be chosen (currently 8).	353	suitable default will be chosen (currently 8).
257		354
258	On error, the callback is called without arguments, otherwise it receives	355	On error, the callback is called without arguments, otherwise it receives
259	two array-refs with path-relative entry names.	356	two array-refs with path-relative entry names.
260		357
…		…
269	Implementation notes.	366	Implementation notes.
270		367
271	The C<aio_readdir> cannot be avoided, but C<stat()>'ing every entry can.	368	The C<aio_readdir> cannot be avoided, but C<stat()>'ing every entry can.
272		369
273	After reading the directory, the modification time, size etc. of the	370	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	371	directory before and after the readdir is checked, and if they match (and
275	link count will be used to decide how many entries are directories (if	372	isn't the current time), the link count will be used to decide how many
276	>= 2). Otherwise, no knowledge of the number of subdirectories will be	373	entries are directories (if >= 2). Otherwise, no knowledge of the number
277	assumed.	374	of subdirectories will be assumed.
278		375
279	Then entires will be sorted into likely directories (everything without a	376	Then entries will be sorted into likely directories (everything without
280	non-initial dot) and likely non-directories (everything else). Then every	377	a non-initial dot currently) and likely non-directories (everything
281	entry + C</.> will be C<stat>'ed, likely directories first. This is often	378	else). Then every entry plus an appended C</.> will be C<stat>'ed,
		379	likely directories first. If that succeeds, it assumes that the entry
		380	is a directory or a symlink to directory (which will be checked
		381	seperately). This is often faster than stat'ing the entry itself because
282	faster because filesystems might detect the type of the entry without	382	filesystems might detect the type of the entry without reading the inode
283	reading the inode data (e.g. ext2s filetype feature). If that succeeds,	383	data (e.g. ext2fs filetype feature).
284	it assumes that the entry is a directory or a symlink to directory (which
285	will be checked seperately).
286		384
287	If the known number of directories has been reached, the rest of the	385	If the known number of directories (link count - 2) has been reached, the
288	entries is assumed to be non-directories.	386	rest of the entries is assumed to be non-directories.
		387
		388	This only works with certainty on POSIX (= UNIX) filesystems, which
		389	fortunately are the vast majority of filesystems around.
		390
		391	It will also likely work on non-POSIX filesystems with reduced efficiency
		392	as those tend to return 0 or 1 as link counts, which disables the
		393	directory counting heuristic.
289		394
290	=cut	395	=cut
291		396
292	sub aio_scandir($$$) {	397	sub aio_scandir($$$) {
293	my ($path, $maxreq, $cb) = @_;	398	my ($path, $maxreq, $cb) = @_;
294		399
		400	my $grp = aio_group;
		401
295	$maxreq = 8 if $maxreq <= 0;	402	$maxreq = 8 if $maxreq <= 0;
296		403
297	# stat once	404	# stat once
298	aio_stat $path, sub {	405	add $grp aio_stat $path, sub {
299	$cb->() if $_[0];	406	return $cb->() if $_[0];
		407	my $now = time;
300	my $hash1 = join ":", (stat _)[0,1,3,7,9];	408	my $hash1 = join ":", (stat _)[0,1,3,7,9];
301		409
302	# read the directory entries	410	# read the directory entries
303	aio_readdir $path, sub {	411	add $grp aio_readdir $path, sub {
304	my $entries = shift	412	my $entries = shift
305	or return $cb->();	413	or return $cb->();
306		414
307	# stat the dir another time	415	# stat the dir another time
308	aio_stat $path, sub {	416	add $grp aio_stat $path, sub {
309	my $hash2 = join ":", (stat _)[0,1,3,7,9];	417	my $hash2 = join ":", (stat _)[0,1,3,7,9];
310		418
311	my $ndirs;	419	my $ndirs;
312		420
313	# take the slow route if anything looks fishy	421	# take the slow route if anything looks fishy
314	if ($hash1 ne $hash2) {	422	if ($hash1 ne $hash2 or (stat _)[9] == $now) {
315	$ndirs = -1;	423	$ndirs = -1;
316	} else {	424	} else {
317	# if nlink == 2, we are finished	425	# if nlink == 2, we are finished
318	# on non-posix-fs's, we rely on nlink < 2	426	# on non-posix-fs's, we rely on nlink < 2
319	$ndirs = (stat _)[3] - 2	427	$ndirs = (stat _)[3] - 2
320	or $cb->([], $entries);	428	or return $cb->([], $entries);
321	}	429	}
322		430
323	# sort into likely dirs and likely nondirs	431	# sort into likely dirs and likely nondirs
324	# dirs == files without ".", short entries first	432	# dirs == files without ".", short entries first
325	$entries = [map $_->[0],	433	$entries = [map $_->[0],
…		…
335	$schedcb = sub {	443	$schedcb = sub {
336	if (@$entries) {	444	if (@$entries) {
337	if ($nreq < $maxreq) {	445	if ($nreq < $maxreq) {
338	my $ent = pop @$entries;	446	my $ent = pop @$entries;
339	$nreq++;	447	$nreq++;
340	aio_stat "$path/$ent/.", sub { $statcb->($_[0], $ent) };	448	add $grp aio_stat "$path/$ent/.", sub { $statcb->($_[0], $ent) };
341	}	449	}
342	} elsif (!$nreq) {	450	} elsif (!$nreq) {
343	# finished	451	# finished
344	undef $statcb;	452	undef $statcb;
345	undef $schedcb;	453	undef $schedcb;
346	$cb->(\@dirs, \@nondirs);	454	$cb->(\@dirs, \@nondirs) if $cb;
347	undef $cb;	455	undef $cb;
348	}	456	}
349	};	457	};
350	$statcb = sub {	458	$statcb = sub {
351	my ($status, $entry) = @_;	459	my ($status, $entry) = @_;
…		…
354	$nreq--;	462	$nreq--;
355	push @nondirs, $entry;	463	push @nondirs, $entry;
356	&$schedcb;	464	&$schedcb;
357	} else {	465	} else {
358	# need to check for real directory	466	# need to check for real directory
359	aio_lstat "$path/$entry", sub {	467	add $grp aio_lstat "$path/$entry", sub {
360	$nreq--;	468	$nreq--;
361		469
362	if (-d _) {	470	if (-d _) {
363	push @dirs, $entry;	471	push @dirs, $entry;
364		472
…		…
377		485
378	&$schedcb while @$entries && $nreq < $maxreq;	486	&$schedcb while @$entries && $nreq < $maxreq;
379	};	487	};
380	};	488	};
381	};	489	};
		490
		491	$grp
382	}	492	}
383		493
384	=item aio_fsync $fh, $callback->($status)	494	=item aio_fsync $fh, $callback->($status)
385		495
386	Asynchronously call fsync on the given filehandle and call the callback	496	Asynchronously call fsync on the given filehandle and call the callback
…		…
391	Asynchronously call fdatasync on the given filehandle and call the	501	Asynchronously call fdatasync on the given filehandle and call the
392	callback with the fdatasync result code.	502	callback with the fdatasync result code.
393		503
394	If this call isn't available because your OS lacks it or it couldn't be	504	If this call isn't available because your OS lacks it or it couldn't be
395	detected, it will be emulated by calling C<fsync> instead.	505	detected, it will be emulated by calling C<fsync> instead.
		506
		507	=item aio_group $callback->()
		508
		509	[EXPERIMENTAL]
		510
		511	This is a very special aio request: Instead of doing something, it is a
		512	container for other aio requests, which is useful if you want to bundle
		513	many requests into a single, composite, request.
		514
		515	Returns an object of class L<IO::AIO::GRP>. See its documentation below
		516	for more info.
		517
		518	Example:
		519
		520	my $grp = aio_group sub {
		521	print "all stats done\n";
		522	};
		523
		524	add $grp
		525	(aio_stat ...),
		526	(aio_stat ...),
		527	...;
		528
		529	=item aio_sleep $fractional_seconds, $callback->() NOT EXPORTED
		530
		531	Mainly used for debugging and benchmarking, this aio request puts one of
		532	the request workers to sleep for the given time.
		533
		534	=back
		535
		536	=head2 IO::AIO::REQ CLASS
		537
		538	All non-aggregate C<aio_*> functions return an object of this class when
		539	called in non-void context.
		540
		541	A request always moves through the following five states in its lifetime,
		542	in order: B<ready> (request has been created, but has not been executed
		543	yet), B<execute> (request is currently being executed), B<pending>
		544	(request has been executed but callback has not been called yet),
		545	B<result> (results are being processed synchronously, includes calling the
		546	callback) and B<done> (request has reached the end of its lifetime and
		547	holds no resources anymore).
		548
		549	=over 4
		550
		551	=item $req->cancel
		552
		553	Cancels the request, if possible. Has the effect of skipping execution
		554	when entering the B<execute> state and skipping calling the callback when
		555	entering the the B<result> state, but will leave the request otherwise
		556	untouched. That means that requests that currently execute will not be
		557	stopped and resources held by the request will not be freed prematurely.
		558
		559	=back
		560
		561	=head2 IO::AIO::GRP CLASS
		562
		563	This class is a subclass of L<IO::AIO::REQ>, so all its methods apply to
		564	objects of this class, too.
		565
		566	A IO::AIO::GRP object is a special request that can contain multiple other
		567	aio requests.
		568
		569	You create one by calling the C<aio_group> constructing function with a
		570	callback that will be called when all contained requests have entered the
		571	C<done> state:
		572
		573	my $grp = aio_group sub {
		574	print "all requests are done\n";
		575	};
		576
		577	You add requests by calling the C<add> method with one or more
		578	C<IO::AIO::REQ> objects:
		579
		580	$grp->add (aio_unlink "...");
		581
		582	add $grp aio_stat "...", sub { ... };
		583
		584	This makes it very easy to create composite requests (see the source of
		585	C<aio_move> for an application) that work and feel like simple requests.
		586
		587	The IO::AIO::GRP objects will be cleaned up during calls to
		588	C<IO::AIO::poll_cb>, just like any other request.
		589
		590	They can be canceled like any other request. Canceling will cancel not
		591	just the request itself, but also all requests it contains.
		592
		593	They can also can also be added to other IO::AIO::GRP objects.
		594
		595	Their lifetime, simplified, looks like this: when they are empty, they
		596	will finish very quickly. If they contain only requests that are in the
		597	C<done> state, they will also finish. Otherwise they will continue to
		598	exist.
		599
		600	=over 4
		601
		602	=item $grp->add (...)
		603
		604	=item add $grp ...
		605
		606	Add one or more
		607	Cancels the request, if possible. Has the effect of skipping execution
		608	when entering the B<execute> state and skipping calling the callback when
		609	entering the the B<result> state, but will leave the request otherwise
		610	untouched. That means that requests that currently execute will not be
		611	stopped and resources held by the request will not be freed prematurely.
396		612
397	=back	613	=back
398		614
399	=head2 SUPPORT FUNCTIONS	615	=head2 SUPPORT FUNCTIONS
400		616
…		…
528	}	744	}
529		745
530	1;	746	1;
531		747
532	=head2 FORK BEHAVIOUR	748	=head2 FORK BEHAVIOUR
		749
		750	This module should do "the right thing" when the process using it forks:
533		751
534	Before the fork, IO::AIO enters a quiescent state where no requests	752	Before the fork, IO::AIO enters a quiescent state where no requests
535	can be added in other threads and no results will be processed. After	753	can be added in other threads and no results will be processed. After
536	the fork the parent simply leaves the quiescent state and continues	754	the fork the parent simply leaves the quiescent state and continues
537	request/result processing, while the child clears the request/result	755	request/result processing, while the child clears the request/result
538	queue (so the requests started before the fork will only be handled in	756	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	757	the parent). Threads will be started on demand until the limit ste in the
540	parent process has been reached again.	758	parent process has been reached again.
541		759
		760	In short: the parent will, after a short pause, continue as if fork had
		761	not been called, while the child will act as if IO::AIO has not been used
		762	yet.
		763
542	=head1 SEE ALSO	764	=head1 SEE ALSO
543		765
544	L<Coro>, L<Linux::AIO>.	766	L<Coro>, L<Linux::AIO> (obsolete).
545		767
546	=head1 AUTHOR	768	=head1 AUTHOR
547		769
548	Marc Lehmann <schmorp@schmorp.de>	770	Marc Lehmann <schmorp@schmorp.de>
549	http://home.schmorp.de/	771	http://home.schmorp.de/

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Comparing IO-AIO/AIO.pm (file contents): Revision 1.40 by root, Tue Aug 30 15:45:10 2005 UTC vs. Revision 1.55 by root, Sun Oct 22 00:49:29 2006 UTC

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Comparing IO-AIO/AIO.pm (file contents):
Revision 1.40 by root, Tue Aug 30 15:45:10 2005 UTC vs.
Revision 1.55 by root, Sun Oct 22 00:49:29 2006 UTC