Linux-AIO/AIO.pm

=head1 NAME

Linux::AIO - linux-specific aio implemented using clone

=head1 SYNOPSIS

 use Linux::AIO;

=head1 DESCRIPTION

This module implements asynchroneous i/o using the means available to
linux - clone. It does not hook into the POSIX aio_* functions because
linux does not yet support these in the kernel. Instead, a number of
threads are started that execute your read/writes and signal their
completion.

=over 4

=cut

package Linux::AIO;

use base 'Exporter';

BEGIN {
   $VERSION = 0.111;

   @EXPORT = qw(aio_read aio_write aio_open aio_close aio_stat aio_lstat);
   @EXPORT_OK = qw(poll_fileno poll_cb min_parallel max_parallel nreqs);

   require XSLoader;
   XSLoader::load Linux::AIO, $VERSION;
}

=item Linux::AIO::min_parallel($nthreads)

Set the minimum number of AIO threads to $nthreads. You I<have> to call
this function with a positive number at leats once, otherwise no threads
will be started and you aio-operations will seem to hang.

=item $fileno = Linux::AIO::poll_fileno

Return the request result pipe filehandle. This filehandle must be polled
for reading. If the pipe becomes readable you have to call C<poll_cb>.

=item Linux::AIO::poll_cb

Process all outstanding events on the result pipe. You have to call this
regularly. Returns the number of events processed.

You can use Event to multiplex, e.g.:

   Event->io(fd => Linux::AIO::poll_fileno,
             poll => 'r', async => 1,
             cb => \&Linux::AIO::poll_cb );


=item Linux::AIO::nreqs

Returns the number of requests currently outstanding.

=item aio_open($pathname, $flags, $mode, $callback)

Asynchronously open or create a file and call the callback with the
filedescriptor.

=item aio_close($fh, $callback)

Asynchronously close a file and call the callback with the result code.

=item aio_read($fh,$offset,$length, $data,$dataoffset,$callback)

=item aio_write($fh,$offset,$length, $data,$dataoffset,$callback)

Reads or writes C<length> bytes from the specified C<fh> and C<offset>
into the scalar given by C<data> and offset C<dataoffset> and calls the
callback without the actual number of bytes read (or undef on error).

=item aio_stat($fh_or_path,$callback)

=item aio_lstat($fh,$callback)

Works like perl's C<stat> or C<lstat> in void context, i.e. the callback
will be called after the stat and the results will be available using
C<stat _> or C<-s _> etc...

Currently, the stats are always 64-bit-stats, i.e. instead of returning an
error when stat'ing a large file, the results will be silently truncated
unless perl itself is compiled with large file support.

=cut

END {
   max_parallel 0;
}

1;

=back

=head1 BUGS

This module has not yet been extensively tested. Watch out!

   - perl-threads/fork interaction poorly tested.
   - aio_open gives a fd, but all other functions expect a filehandle.

=head1 SEE ALSO

L<Coro>.

=head1 AUTHOR

 Marc Lehmann <pcg@goof.com>
 http://www.goof.com/pcg/marc/

=cut

Revision:	1.12
Committed:	Sat May 18 21:48:36 2002 UTC (22 years ago) by root
Branch:	MAIN
Changes since 1.11:	+1 -1 lines
Log Message:	* empty log message *
#	User	Rev	Content
1	root	1.1	=head1 NAME
2
3			Linux::AIO - linux-specific aio implemented using clone
4
5			=head1 SYNOPSIS
6
7			use Linux::AIO;
8
9			=head1 DESCRIPTION
10
11	root	1.3	This module implements asynchroneous i/o using the means available to
12			linux - clone. It does not hook into the POSIX aio_* functions because
13			linux does not yet support these in the kernel. Instead, a number of
14			threads are started that execute your read/writes and signal their
15			completion.
16
17	root	1.1	=over 4
18
19			=cut
20
21			package Linux::AIO;
22
23	root	1.2	use base 'Exporter';
24
25	root	1.1	BEGIN {
26	root	1.12	$VERSION = 0.111;
27	root	1.1
28	root	1.10	@EXPORT = qw(aio_read aio_write aio_open aio_close aio_stat aio_lstat);
29	root	1.2	@EXPORT_OK = qw(poll_fileno poll_cb min_parallel max_parallel nreqs);
30
31	root	1.1	require XSLoader;
32			XSLoader::load Linux::AIO, $VERSION;
33			}
34
35			=item Linux::AIO::min_parallel($nthreads)
36
37	root	1.3	Set the minimum number of AIO threads to $nthreads. You I<have> to call
38			this function with a positive number at leats once, otherwise no threads
39			will be started and you aio-operations will seem to hang.
40	root	1.1
41	root	1.2	=item $fileno = Linux::AIO::poll_fileno
42
43			Return the request result pipe filehandle. This filehandle must be polled
44			for reading. If the pipe becomes readable you have to call C<poll_cb>.
45
46			=item Linux::AIO::poll_cb
47
48			Process all outstanding events on the result pipe. You have to call this
49			regularly. Returns the number of events processed.
50
51	root	1.3	You can use Event to multiplex, e.g.:
52
53			Event->io(fd => Linux::AIO::poll_fileno,
54			poll => 'r', async => 1,
55			cb => \&Linux::AIO::poll_cb );
56
57
58	root	1.2	=item Linux::AIO::nreqs
59
60			Returns the number of requests currently outstanding.
61	root	1.4
62	root	1.10	=item aio_open($pathname, $flags, $mode, $callback)
63
64			Asynchronously open or create a file and call the callback with the
65			filedescriptor.
66
67			=item aio_close($fh, $callback)
68
69			Asynchronously close a file and call the callback with the result code.
70
71	root	1.4	=item aio_read($fh,$offset,$length, $data,$dataoffset,$callback)
72	root	1.9
73			=item aio_write($fh,$offset,$length, $data,$dataoffset,$callback)
74	root	1.4
75			Reads or writes C<length> bytes from the specified C<fh> and C<offset>
76			into the scalar given by C<data> and offset C<dataoffset> and calls the
77			callback without the actual number of bytes read (or undef on error).
78
79	root	1.10	=item aio_stat($fh_or_path,$callback)
80	root	1.4
81	root	1.10	=item aio_lstat($fh,$callback)
82	root	1.5
83	root	1.10	Works like perl's C<stat> or C<lstat> in void context, i.e. the callback
84			will be called after the stat and the results will be available using
85			C<stat _> or C<-s _> etc...
86	root	1.5
87	root	1.10	Currently, the stats are always 64-bit-stats, i.e. instead of returning an
88			error when stat'ing a large file, the results will be silently truncated
89			unless perl itself is compiled with large file support.
90	root	1.2
91	root	1.1	=cut
92	root	1.2
93			END {
94			max_parallel 0;
95			}
96	root	1.1
97			1;
98
99			=back
100
101			=head1 BUGS
102
103			This module has not yet been extensively tested. Watch out!
104
105	root	1.11	- perl-threads/fork interaction poorly tested.
106			- aio_open gives a fd, but all other functions expect a filehandle.
107	root	1.6
108	root	1.1	=head1 SEE ALSO
109
110			L<Coro>.
111
112			=head1 AUTHOR
113
114			Marc Lehmann <pcg@goof.com>
115			http://www.goof.com/pcg/marc/
116
117			=cut
118