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

Comparing IO-AIO/AIO.pm (file contents):
Revision 1.55 by root, Sun Oct 22 00:49:29 2006 UTC vs.
Revision 1.67 by root, Tue Oct 24 02:25:16 2006 UTC

…		…
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		19
20	use IO::AIO 2; # version has aio objects	20	# version 2+ has request and group objects
		21	use IO::AIO 2;
21		22
22	my $req = aio_unlink "/tmp/file", sub { };	23	my $req = aio_unlink "/tmp/file", sub { };
23	$req->cancel; # cancel request if still in queue	24	$req->cancel; # cancel request if still in queue
24		25
25	# AnyEvent	26	my $grp = aio_group sub { print "all stats done\n" };
		27	add $grp aio_stat "..." for ...;
		28
		29	# AnyEvent integration
26	open my $fh, "<&=" . IO::AIO::poll_fileno or die "$!";	30	open my $fh, "<&=" . IO::AIO::poll_fileno or die "$!";
27	my $w = AnyEvent->io (fh => $fh, poll => 'r', cb => sub { IO::AIO::poll_cb });	31	my $w = AnyEvent->io (fh => $fh, poll => 'r', cb => sub { IO::AIO::poll_cb });
28		32
29	# Event	33	# Event integration
30	Event->io (fd => IO::AIO::poll_fileno,	34	Event->io (fd => IO::AIO::poll_fileno,
31	poll => 'r',	35	poll => 'r',
32	cb => \&IO::AIO::poll_cb);	36	cb => \&IO::AIO::poll_cb);
33		37
34	# Glib/Gtk2	38	# Glib/Gtk2 integration
35	add_watch Glib::IO IO::AIO::poll_fileno,	39	add_watch Glib::IO IO::AIO::poll_fileno,
36	in => sub { IO::AIO::poll_cb; 1 };	40	in => sub { IO::AIO::poll_cb; 1 };
37		41
38	# Tk	42	# Tk integration
39	Tk::Event::IO->fileevent (IO::AIO::poll_fileno, "",	43	Tk::Event::IO->fileevent (IO::AIO::poll_fileno, "",
40	readable => \&IO::AIO::poll_cb);	44	readable => \&IO::AIO::poll_cb);
41		45
42	# Danga::Socket	46	# Danga::Socket integration
43	Danga::Socket->AddOtherFds (IO::AIO::poll_fileno =>	47	Danga::Socket->AddOtherFds (IO::AIO::poll_fileno =>
44	\&IO::AIO::poll_cb);	48	\&IO::AIO::poll_cb);
45		49
46
47	=head1 DESCRIPTION	50	=head1 DESCRIPTION
48		51
49	This module implements asynchronous I/O using whatever means your	52	This module implements asynchronous I/O using whatever means your
50	operating system supports.	53	operating system supports.
51		54
52	Currently, a number of threads are started that execute your read/writes	55	Currently, a number of threads are started that execute your read/writes
53	and signal their completion. You don't need thread support in your libc or	56	and signal their completion. You don't need thread support in perl, and
54	perl, and the threads created by this module will not be visible to the	57	the threads created by this module will not be visible to perl. In the
55	pthreads library. In the future, this module might make use of the native	58	future, this module might make use of the native aio functions available
56	aio functions available on many operating systems. However, they are often	59	on many operating systems. However, they are often not well-supported
57	not well-supported (Linux doesn't allow them on normal files currently,	60	(Linux doesn't allow them on normal files currently, for example),
58	for example), and they would only support aio_read and aio_write, so the	61	and they would only support aio_read and aio_write, so the remaining
59	remaining functionality would have to be implemented using threads anyway.	62	functionality would have to be implemented using threads anyway.
60		63
61	Although the module will work with in the presence of other threads, it is	64	Although the module will work with in the presence of other threads, it is
62	currently not reentrant, so use appropriate locking yourself, always call	65	currently not reentrant, so use appropriate locking yourself, always call
63	C<poll_cb> from within the same thread, or never call C<poll_cb> (or other	66	C<poll_cb> from within the same thread, or never call C<poll_cb> (or other
64	C<aio_> functions) recursively.	67	C<aio_> functions) recursively.
…		…
73	use base 'Exporter';	76	use base 'Exporter';
74		77
75	BEGIN {	78	BEGIN {
76	our $VERSION = '2.0';	79	our $VERSION = '2.0';
77		80
78	our @EXPORT = qw(aio_sendfile aio_read aio_write aio_open aio_close aio_stat	81	our @AIO_REQ = qw(aio_sendfile aio_read aio_write aio_open aio_close aio_stat
79	aio_lstat aio_unlink aio_rmdir aio_readdir aio_scandir aio_symlink	82	aio_lstat aio_unlink aio_rmdir aio_readdir aio_scandir aio_symlink
80	aio_fsync aio_fdatasync aio_readahead aio_rename aio_link aio_move	83	aio_fsync aio_fdatasync aio_readahead aio_rename aio_link aio_move
81	aio_group);	84	aio_group aio_nop);
82	our @EXPORT_OK = qw(poll_fileno poll_cb min_parallel max_parallel max_outstanding nreqs);	85	our @EXPORT = (@AIO_REQ, qw(aioreq_pri));
		86	our @EXPORT_OK = qw(poll_fileno poll_cb poll_wait flush
		87	min_parallel max_parallel max_outstanding nreqs);
83		88
84	@IO::AIO::GRP::ISA = 'IO::AIO::REQ';	89	@IO::AIO::GRP::ISA = 'IO::AIO::REQ';
85		90
86	require XSLoader;	91	require XSLoader;
87	XSLoader::load ("IO::AIO", $VERSION);	92	XSLoader::load ("IO::AIO", $VERSION);
…		…
179	print "read $_[0] bytes: <$buffer>\n";	184	print "read $_[0] bytes: <$buffer>\n";
180	};	185	};
181		186
182	=item aio_move $srcpath, $dstpath, $callback->($status)	187	=item aio_move $srcpath, $dstpath, $callback->($status)
183		188
		189	[EXPERIMENTAL due to internal aio_group use]
		190
184	Try to move the I<file> (directories not supported as either source or	191	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	192	destination) from C<$srcpath> to C<$dstpath> and call the callback with
186	the C<0> (error) or C<-1> ok.	193	the C<0> (error) or C<-1> ok.
187		194
188	This is a composite request that tries to rename(2) the file first. If	195	This is a composite request that tries to rename(2) the file first. If
…		…
198	=cut	205	=cut
199		206
200	sub aio_move($$$) {	207	sub aio_move($$$) {
201	my ($src, $dst, $cb) = @_;	208	my ($src, $dst, $cb) = @_;
202		209
203	my $grp = aio_group;	210	my $grp = aio_group $cb;
204		211
205	add $grp aio_rename $src, $dst, sub {	212	add $grp aio_rename $src, $dst, sub {
206	if ($_[0] && $! == EXDEV) {	213	if ($_[0] && $! == EXDEV) {
207	add $grp aio_open $src, O_RDONLY, 0, sub {	214	add $grp aio_open $src, O_RDONLY, 0, sub {
208	if (my $src_fh = $_[0]) {	215	if (my $src_fh = $_[0]) {
…		…
218	chmod $stat[2] & 07777, $dst_fh;	225	chmod $stat[2] & 07777, $dst_fh;
219	chown $stat[4], $stat[5], $dst_fh;	226	chown $stat[4], $stat[5], $dst_fh;
220	close $dst_fh;	227	close $dst_fh;
221		228
222	add $grp aio_unlink $src, sub {	229	add $grp aio_unlink $src, sub {
223	$cb->($_[0]);	230	$grp->result ($_[0]);
224	};	231	};
225	} else {	232	} else {
226	my $errno = $!;	233	my $errno = $!;
227	add $grp aio_unlink $dst, sub {	234	add $grp aio_unlink $dst, sub {
228	$! = $errno;	235	$! = $errno;
229	$cb->(-1);	236	$grp->result (-1);
230	};	237	};
231	}	238	}
232	};	239	};
233	} else {	240	} else {
234	$cb->(-1);	241	$grp->result (-1);
235	}	242	}
236	},	243	},
237		244
238	} else {	245	} else {
239	$cb->(-1);	246	$grp->result (-1);
240	}	247	}
241	};	248	};
242	} else {	249	} else {
243	$cb->($_[0]);	250	$grp->result ($_[0]);
244	}	251	}
245	};	252	};
246		253
247	$grp	254	$grp
248	}	255	}
…		…
340	The callback a single argument which is either C<undef> or an array-ref	347	The callback a single argument which is either C<undef> or an array-ref
341	with the filenames.	348	with the filenames.
342		349
343	=item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs)	350	=item aio_scandir $path, $maxreq, $callback->($dirs, $nondirs)
344		351
		352	[EXPERIMENTAL due to internal aio_group use]
		353
345	Scans a directory (similar to C<aio_readdir>) but additionally tries to	354	Scans a directory (similar to C<aio_readdir>) but additionally tries to
346	separate the entries of directory C<$path> into two sets of names, ones	355	separate the entries of directory C<$path> into two sets of names, ones
347	you can recurse into (directories or links to them), and ones you cannot	356	you can recurse into (directories or links to them), and ones you cannot
348	recurse into (everything else).	357	recurse into (everything else).
349		358
350	C<aio_scandir> is a composite request that consists of many sub	359	C<aio_scandir> is a composite request that creates of many sub requests_
351	requests. C<$maxreq> specifies the maximum number of outstanding aio	360	C<$maxreq> specifies the maximum number of outstanding aio requests that
352	requests that this function generates. If it is C<< <= 0 >>, then a	361	this function generates. If it is C<< <= 0 >>, then a suitable default
353	suitable default will be chosen (currently 8).	362	will be chosen (currently 6).
354		363
355	On error, the callback is called without arguments, otherwise it receives	364	On error, the callback is called without arguments, otherwise it receives
356	two array-refs with path-relative entry names.	365	two array-refs with path-relative entry names.
357		366
358	Example:	367	Example:
…		…
395	=cut	404	=cut
396		405
397	sub aio_scandir($$$) {	406	sub aio_scandir($$$) {
398	my ($path, $maxreq, $cb) = @_;	407	my ($path, $maxreq, $cb) = @_;
399		408
400	my $grp = aio_group;	409	my $grp = aio_group $cb;
401		410
402	$maxreq = 8 if $maxreq <= 0;	411	$maxreq = 6 if $maxreq <= 0;
403		412
404	# stat once	413	# stat once
405	add $grp aio_stat $path, sub {	414	add $grp aio_stat $path, sub {
406	return $cb->() if $_[0];	415	return $grp->result () if $_[0];
407	my $now = time;	416	my $now = time;
408	my $hash1 = join ":", (stat _)[0,1,3,7,9];	417	my $hash1 = join ":", (stat _)[0,1,3,7,9];
409		418
410	# read the directory entries	419	# read the directory entries
411	add $grp aio_readdir $path, sub {	420	add $grp aio_readdir $path, sub {
412	my $entries = shift	421	my $entries = shift
413	or return $cb->();	422	or return $grp->result ();
414		423
415	# stat the dir another time	424	# stat the dir another time
416	add $grp aio_stat $path, sub {	425	add $grp aio_stat $path, sub {
417	my $hash2 = join ":", (stat _)[0,1,3,7,9];	426	my $hash2 = join ":", (stat _)[0,1,3,7,9];
418		427
…		…
423	$ndirs = -1;	432	$ndirs = -1;
424	} else {	433	} else {
425	# if nlink == 2, we are finished	434	# if nlink == 2, we are finished
426	# on non-posix-fs's, we rely on nlink < 2	435	# on non-posix-fs's, we rely on nlink < 2
427	$ndirs = (stat _)[3] - 2	436	$ndirs = (stat _)[3] - 2
428	or return $cb->([], $entries);	437	or return $grp->result ([], $entries);
429	}	438	}
430		439
431	# sort into likely dirs and likely nondirs	440	# sort into likely dirs and likely nondirs
432	# dirs == files without ".", short entries first	441	# dirs == files without ".", short entries first
433	$entries = [map $_->[0],	442	$entries = [map $_->[0],
…		…
438	my (@dirs, @nondirs);	447	my (@dirs, @nondirs);
439		448
440	my ($statcb, $schedcb);	449	my ($statcb, $schedcb);
441	my $nreq = 0;	450	my $nreq = 0;
442		451
		452	my $statgrp = add $grp aio_group;
		453
443	$schedcb = sub {	454	$schedcb = sub {
444	if (@$entries) {	455	if (@$entries) {
445	if ($nreq < $maxreq) {	456	if ($nreq < $maxreq) {
446	my $ent = pop @$entries;	457	my $ent = pop @$entries;
447	$nreq++;	458	$nreq++;
448	add $grp aio_stat "$path/$ent/.", sub { $statcb->($_[0], $ent) };	459	add $statgrp aio_stat "$path/$ent/.", sub { $statcb->($_[0], $ent) };
449	}	460	}
450	} elsif (!$nreq) {	461	} elsif (!$nreq) {
451	# finished	462	# finished
		463	$statgrp->cancel;
452	undef $statcb;	464	undef $statcb;
453	undef $schedcb;	465	undef $schedcb;
454	$cb->(\@dirs, \@nondirs) if $cb;	466	$grp->result (\@dirs, \@nondirs);
455	undef $cb;
456	}	467	}
457	};	468	};
458	$statcb = sub {	469	$statcb = sub {
459	my ($status, $entry) = @_;	470	my ($status, $entry) = @_;
460		471
…		…
502	callback with the fdatasync result code.	513	callback with the fdatasync result code.
503		514
504	If this call isn't available because your OS lacks it or it couldn't be	515	If this call isn't available because your OS lacks it or it couldn't be
505	detected, it will be emulated by calling C<fsync> instead.	516	detected, it will be emulated by calling C<fsync> instead.
506		517
507	=item aio_group $callback->()	518	=item aio_group $callback->(...)
508		519
509	[EXPERIMENTAL]	520	[EXPERIMENTAL]
510		521
511	This is a very special aio request: Instead of doing something, it is a	522	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	523	container for other aio requests, which is useful if you want to bundle
…		…
524	add $grp	535	add $grp
525	(aio_stat ...),	536	(aio_stat ...),
526	(aio_stat ...),	537	(aio_stat ...),
527	...;	538	...;
528		539
		540	=item aio_nop $callback->()
		541
		542	This is a special request - it does nothing in itself and is only used for
		543	side effects, such as when you want to add a dummy request to a group so
		544	that finishing the requests in the group depends on executing the given
		545	code.
		546
		547	While this request does nothing, it still goes through the execution
		548	phase and still requires a worker thread. Thus, the callback will not
		549	be executed immediately but only after other requests in the queue have
		550	entered their execution phase. This can be used to measure request
		551	latency.
		552
529	=item aio_sleep $fractional_seconds, $callback->() NOT EXPORTED	553	=item IO::AIO::aio_sleep $fractional_seconds, $callback->() NOT EXPORTED
530		554
531	Mainly used for debugging and benchmarking, this aio request puts one of	555	Mainly used for debugging and benchmarking, this aio request puts one of
532	the request workers to sleep for the given time.	556	the request workers to sleep for the given time.
		557
		558	While it is theoretically handy to have simple I/O scheduling requests
		559	like sleep and file handle readable/writable, the overhead this creates
		560	is immense, so do not use this function except to put your application
		561	under artificial I/O pressure.
533		562
534	=back	563	=back
535		564
536	=head2 IO::AIO::REQ CLASS	565	=head2 IO::AIO::REQ CLASS
537		566
…		…
546	callback) and B<done> (request has reached the end of its lifetime and	575	callback) and B<done> (request has reached the end of its lifetime and
547	holds no resources anymore).	576	holds no resources anymore).
548		577
549	=over 4	578	=over 4
550		579
551	=item $req->cancel	580	=item cancel $req
552		581
553	Cancels the request, if possible. Has the effect of skipping execution	582	Cancels the request, if possible. Has the effect of skipping execution
554	when entering the B<execute> state and skipping calling the callback when	583	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	584	entering the the B<result> state, but will leave the request otherwise
556	untouched. That means that requests that currently execute will not be	585	untouched. That means that requests that currently execute will not be
557	stopped and resources held by the request will not be freed prematurely.	586	stopped and resources held by the request will not be freed prematurely.
558		587
		588	=item cb $req $callback->(...)
		589
		590	Replace (or simply set) the callback registered to the request.
		591
559	=back	592	=back
560		593
561	=head2 IO::AIO::GRP CLASS	594	=head2 IO::AIO::GRP CLASS
562		595
563	This class is a subclass of L<IO::AIO::REQ>, so all its methods apply to	596	This class is a subclass of L<IO::AIO::REQ>, so all its methods apply to
…		…
577	You add requests by calling the C<add> method with one or more	610	You add requests by calling the C<add> method with one or more
578	C<IO::AIO::REQ> objects:	611	C<IO::AIO::REQ> objects:
579		612
580	$grp->add (aio_unlink "...");	613	$grp->add (aio_unlink "...");
581		614
582	add $grp aio_stat "...", sub { ... };	615	add $grp aio_stat "...", sub {
		616	$_[0] or return $grp->result ("error");
		617
		618	# add another request dynamically, if first succeeded
		619	add $grp aio_open "...", sub {
		620	$grp->result ("ok");
		621	};
		622	};
583		623
584	This makes it very easy to create composite requests (see the source of	624	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.	625	C<aio_move> for an application) that work and feel like simple requests.
586		626
		627	=over 4
		628
587	The IO::AIO::GRP objects will be cleaned up during calls to	629	=item * The IO::AIO::GRP objects will be cleaned up during calls to
588	C<IO::AIO::poll_cb>, just like any other request.	630	C<IO::AIO::poll_cb>, just like any other request.
589		631
590	They can be canceled like any other request. Canceling will cancel not	632	=item * They can be canceled like any other request. Canceling will cancel not
591	just the request itself, but also all requests it contains.	633	only the request itself, but also all requests it contains.
592		634
593	They can also can also be added to other IO::AIO::GRP objects.	635	=item * They can also can also be added to other IO::AIO::GRP objects.
		636
		637	=item * You must not add requests to a group from within the group callback (or
		638	any later time).
		639
		640	=item * This does not harmonise well with C<max_outstanding>, so best do
		641	not combine C<aio_group> with it. Groups and feeders are recommended for
		642	this kind of concurrency-limiting.
		643
		644	=back
594		645
595	Their lifetime, simplified, looks like this: when they are empty, they	646	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	647	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	648	C<done> state, they will also finish. Otherwise they will continue to
598	exist.	649	exist.
599		650
		651	That means after creating a group you have some time to add requests. And
		652	in the callbacks of those requests, you can add further requests to the
		653	group. And only when all those requests have finished will the the group
		654	itself finish.
		655
600	=over 4	656	=over 4
601		657
		658	=item add $grp ...
		659
602	=item $grp->add (...)	660	=item $grp->add (...)
603		661
604	=item add $grp ...	662	Add one or more requests to the group. Any type of L<IO::AIO::REQ> can
		663	be added, including other groups, as long as you do not create circular
		664	dependencies.
605		665
606	Add one or more	666	Returns all its arguments.
607	Cancels the request, if possible. Has the effect of skipping execution	667
608	when entering the B<execute> state and skipping calling the callback when	668	=item $grp->result (...)
609	entering the the B<result> state, but will leave the request otherwise	669
610	untouched. That means that requests that currently execute will not be	670	Set the result value(s) that will be passed to the group callback when all
611	stopped and resources held by the request will not be freed prematurely.	671	subrequests have finished. By default, no argument will be passed.
		672
		673	=item feed $grp $callback->($grp)
		674
		675	[VERY EXPERIMENTAL]
		676
		677	Sets a feeder/generator on this group: every group can have an attached
		678	generator that generates requests if idle. The idea behind this is that,
		679	although you could just queue as many requests as you want in a group,
		680	this might starve other requests for a potentially long time. For
		681	example, C<aio_scandir> might generate hundreds of thousands C<aio_stat>
		682	requests, delaying any later requests for a long time.
		683
		684	To avoid this, and allow incremental generation of requests, you can
		685	instead a group and set a feeder on it that generates those requests. The
		686	feed callback will be called whenever there are few enough (see C<feed_limit>,
		687	below) requests active in the group itself and is expected to queue more
		688	requests.
		689
		690	The feed can queue as many requests as it likes (i.e. C<add> does not
		691	impose any limits).
		692
		693	If the feed does not queue more requests when called, it will be
		694	automatically removed from the group.
		695
		696	If the feed limit is C<0>, it will be set to C<2> automatically.
		697
		698	Example:
		699
		700	# stat all files in @files, but only ever use four aio requests concurrently:
		701
		702	my $grp = aio_group sub { print "finished\n" };
		703	feed_limit $grp 4;
		704	feed $grp sub {
		705	my $file = pop @files
		706	or return;
		707
		708	add $grp aio_stat $file, sub { ... };
		709	};
		710
		711	=item feed_limit $grp $num
		712
		713	Sets the feeder limit for the group: The feeder will be called whenever
		714	the group contains less than this many requests.
		715
		716	Setting the limit to C<0> will pause the feeding process.
612		717
613	=back	718	=back
614		719
615	=head2 SUPPORT FUNCTIONS	720	=head2 SUPPORT FUNCTIONS
616		721
…		…
674	IO::AIO::poll_wait, IO::AIO::poll_cb	779	IO::AIO::poll_wait, IO::AIO::poll_cb
675	if IO::AIO::nreqs;	780	if IO::AIO::nreqs;
676		781
677	=item IO::AIO::min_parallel $nthreads	782	=item IO::AIO::min_parallel $nthreads
678		783
679	Set the minimum number of AIO threads to C<$nthreads>. The current default	784	Set the minimum number of AIO threads to C<$nthreads>. The current
680	is C<4>, which means four asynchronous operations can be done at one time	785	default is C<8>, which means eight asynchronous operations can execute
681	(the number of outstanding operations, however, is unlimited).	786	concurrently at any one time (the number of outstanding requests,
		787	however, is unlimited).
682		788
683	IO::AIO starts threads only on demand, when an AIO request is queued and	789	IO::AIO starts threads only on demand, when an AIO request is queued and
684	no free thread exists.	790	no free thread exists.
685		791
686	It is recommended to keep the number of threads low, as some Linux	792	It is recommended to keep the number of threads relatively low, as some
687	kernel versions will scale negatively with the number of threads (higher	793	Linux kernel versions will scale negatively with the number of threads
688	parallelity => MUCH higher latency). With current Linux 2.6 versions, 4-32	794	(higher parallelity => MUCH higher latency). With current Linux 2.6
689	threads should be fine.	795	versions, 4-32 threads should be fine.
690		796
691	Under most circumstances you don't need to call this function, as the	797	Under most circumstances you don't need to call this function, as the
692	module selects a default that is suitable for low to moderate load.	798	module selects a default that is suitable for low to moderate load.
693		799
694	=item IO::AIO::max_parallel $nthreads	800	=item IO::AIO::max_parallel $nthreads
…		…
705		811
706	Under normal circumstances you don't need to call this function.	812	Under normal circumstances you don't need to call this function.
707		813
708	=item $oldnreqs = IO::AIO::max_outstanding $nreqs	814	=item $oldnreqs = IO::AIO::max_outstanding $nreqs
709		815
		816	[DEPRECATED]
		817
710	Sets the maximum number of outstanding requests to C<$nreqs>. If you	818	Sets the maximum number of outstanding requests to C<$nreqs>. If you
711	try to queue up more than this number of requests, the caller will block until	819	try to queue up more than this number of requests, the caller will block until
712	some requests have been handled.	820	some requests have been handled.
713		821
714	The default is very large, so normally there is no practical limit. If you	822	The default is very large, so normally there is no practical limit. If you
715	queue up many requests in a loop it often improves speed if you set	823	queue up many requests in a loop it often improves speed if you set
716	this to a relatively low number, such as C<100>.	824	this to a relatively low number, such as C<100>.
		825
		826	This function does not work well together with C<aio_group>'s, and their
		827	feeder interface is better suited to limiting concurrency, so do not use
		828	this function.
717		829
718	Under normal circumstances you don't need to call this function.	830	Under normal circumstances you don't need to call this function.
719		831
720	=back	832	=back
721		833
…		…
735	or return undef;	847	or return undef;
736		848
737	*$sym	849	*$sym
738	}	850	}
739		851
740	min_parallel 4;	852	min_parallel 8;
741		853
742	END {	854	END {
743	max_parallel 0;	855	max_parallel 0;
744	}	856	}
745		857
…		…
759		871
760	In short: the parent will, after a short pause, continue as if fork had	872	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	873	not been called, while the child will act as if IO::AIO has not been used
762	yet.	874	yet.
763		875
		876	=head2 MEMORY USAGE
		877
		878	Each aio request uses - depending on your architecture - around 128 bytes
		879	of memory. In addition, stat requests need a stat buffer (possibly a few
		880	hundred bytes). Perl scalars and other data passed into aio requests will
		881	also be locked.
		882
		883	This is now awfully much, so queuing lots of requests is not usually a
		884	problem.
		885
		886	Each thread needs a stack area which is usually around 16k, sometimes much
		887	larger, depending on the OS.
		888
764	=head1 SEE ALSO	889	=head1 SEE ALSO
765		890
766	L<Coro>, L<Linux::AIO> (obsolete).	891	L<Coro>, L<Linux::AIO> (obsolete).
767		892
768	=head1 AUTHOR	893	=head1 AUTHOR

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Comparing IO-AIO/AIO.pm (file contents): Revision 1.55 by root, Sun Oct 22 00:49:29 2006 UTC vs. Revision 1.67 by root, Tue Oct 24 02:25:16 2006 UTC

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Comparing IO-AIO/AIO.pm (file contents):
Revision 1.55 by root, Sun Oct 22 00:49:29 2006 UTC vs.
Revision 1.67 by root, Tue Oct 24 02:25:16 2006 UTC