AnyEvent/lib/AE.pm

=head1 NAME

AE - simpler/faster/newer/cooler AnyEvent API

=head1 SYNOPSIS

  use AnyEvent; # not AE

=head1 DESCRIPTION

This module documents the new simpler AnyEvent API.

The rationale for the new API is that experience with L<EV> shows that
this API actually "works", despite it's lack of extensibility, leading to
a shorter, easier and faster API.

The main difference to AnyEvent is that instead of method calls, function
calls are used, and that no named arguments are used.

This makes calls to watcher creation functions really short, which can
make a program more readable, despite the lack of named parameters.
Function calls also allow more static type checking than method calls, so
many mistakes are caught at compiletime with this API.

Also, some backends (Perl and EV) are so fast that the method call
overhead is very noticeable (with EV it increases the execution time five-
to six-fold, with Perl the method call overhead is about a factor of two).

At the moment, there will be no checking (L<AnyEvent::Strict> does not
affect his API), so the L<AnyEvent> API has a definite advantage here
still.

Note that the C<AE> API is an alternative to, not the future version of,
the AnyEvent API. Both APIs can be used interchangably and and there are
no plans to "switch", so if in doubt, feel free to use the L<AnyEvent>
API in new code.

As the AE API is complementary, not everything in the AnyEvent API is
available, so you still need to use AnyEvent for the finer stuff. Also,
you should not C<use AE> directly, C<use AnyEvent> will provide the AE
namespace.

=head2 FUNCTIONS

This section briefly describes the alternative watcher
constructors. Semantics and any methods are not described here, please
refer to the L<AnyEvent> manpage for the details.

=over 4

=cut

package AE;

use AnyEvent (); # BEGIN { AnyEvent::common_sense }

our $VERSION = $AnyEvent::VERSION;

=item $w = AE::io $fh_or_fd, $watch_write, $cb

Creates an I/O watcher that listens for read events (C<$watch_write>
false) or write events (C<$watch_write> is true) on the file handle or
file descriptor C<$fh_or_fd>.

The callback C<$cb> is invoked as soon and as long as I/O of the type
specified by C<$watch_write>) can be done on the file handle/descriptor.

Example: wait until STDIN becomes readable.

  $stdin_ready = AE::io *STDIN, 0, sub { scalar <STDIN> };

Example. wait until STDOUT becomes writable and print something.

  $stdout_ready = AE::io *STDOUT, 1, sub { print STDOUT "woaw\n" };

=item $w = AE::timer $after, $interval, $cb

Creates a timer watcher that invokes the callback C<$cb> after at least
C<$after> second have passed (C<$after> can be negative or C<0>).

If C<$interval> is C<0>, then the clalback will only be invoked once,
otherwise it must be a positive number of seconds that specified the
interval between successive invocations of the callback.

Example: print "too late" after at least one second has passed.

  $timer_once = AE::timer 1, 0, sub { print "too late\n" };

Example: print "blubb" once a second, starting as soon as possible.

  $timer_repeated = AE::timer 0, 1, sub { print "blubb\n" };

=item $w = AE::signal $signame, $cb

Invoke the callback c<$cb> each time one or more occurences of the named
signal C<$signame> are detected.

=item $w = AE::child $pid, $cb

Invokes the callbakc C<$cb> when the child with the given C<$pid> exits
(or all children, when C<$pid> is zero).

The callback will get the actual pid and exit status as arguments.

=item $w = AE::idle $cb

Invoke the callback C<$cb> each time the event loop is "idle" (has no
events outstanding), but do not prevent the event loop from polling for
more events.

=item $cv = AE::cv

=item $cv = AE::cv { BLOCK }

Create a new condition variable. The first form is identical to C<<
AnyEvent->condvar >>, the second form additionally sets the callback (as
if the C<cb> method is called on the condition variable).

=item AE::now

Returns the current event loop time (may be cached by the event loop).

=item AE::now_update

Ensures that the current event loop time is up to date.

=item AE::time

Return the current time (not cached, always consults a hardware clock).

=back

=head1 AUTHOR

 Marc Lehmann <schmorp@schmorp.de>
 http://home.schmorp.de/

=cut

1

Revision:	1.6
Committed:	Wed Mar 24 21:22:57 2010 UTC (14 years, 3 months ago) by root
Branch:	MAIN
Changes since 1.5:	+4 -3 lines
Log Message:	* empty log message *
#	User	Rev	Content
1	root	1.1	=head1 NAME
2
3			AE - simpler/faster/newer/cooler AnyEvent API
4
5			=head1 SYNOPSIS
6
7	root	1.2	use AnyEvent; # not AE
8	root	1.1
9			=head1 DESCRIPTION
10
11	root	1.2	This module documents the new simpler AnyEvent API.
12	root	1.1
13			The rationale for the new API is that experience with L<EV> shows that
14	root	1.3	this API actually "works", despite it's lack of extensibility, leading to
15			a shorter, easier and faster API.
16	root	1.1
17	root	1.2	The main difference to AnyEvent is that instead of method calls, function
18			calls are used, and that no named arguments are used.
19
20			This makes calls to watcher creation functions really short, which can
21			make a program more readable, despite the lack of named parameters.
22			Function calls also allow more static type checking than method calls, so
23			many mistakes are caught at compiletime with this API.
24
25			Also, some backends (Perl and EV) are so fast that the method call
26	root	1.6	overhead is very noticeable (with EV it increases the execution time five-
27			to six-fold, with Perl the method call overhead is about a factor of two).
28	root	1.2
29			At the moment, there will be no checking (L<AnyEvent::Strict> does not
30			affect his API), so the L<AnyEvent> API has a definite advantage here
31			still.
32
33			Note that the C<AE> API is an alternative to, not the future version of,
34			the AnyEvent API. Both APIs can be used interchangably and and there are
35	root	1.6	no plans to "switch", so if in doubt, feel free to use the L<AnyEvent>
36			API in new code.
37	root	1.2
38			As the AE API is complementary, not everything in the AnyEvent API is
39			available, so you still need to use AnyEvent for the finer stuff. Also,
40			you should not C<use AE> directly, C<use AnyEvent> will provide the AE
41			namespace.
42
43			=head2 FUNCTIONS
44
45			This section briefly describes the alternative watcher
46			constructors. Semantics and any methods are not described here, please
47			refer to the L<AnyEvent> manpage for the details.
48
49			=over 4
50	root	1.1
51			=cut
52
53			package AE;
54
55			use AnyEvent (); # BEGIN { AnyEvent::common_sense }
56
57	root	1.4	our $VERSION = $AnyEvent::VERSION;
58
59	root	1.2	=item $w = AE::io $fh_or_fd, $watch_write, $cb
60
61			Creates an I/O watcher that listens for read events (C<$watch_write>
62			false) or write events (C<$watch_write> is true) on the file handle or
63			file descriptor C<$fh_or_fd>.
64
65			The callback C<$cb> is invoked as soon and as long as I/O of the type
66			specified by C<$watch_write>) can be done on the file handle/descriptor.
67
68			Example: wait until STDIN becomes readable.
69
70			$stdin_ready = AE::io *STDIN, 0, sub { scalar <STDIN> };
71
72			Example. wait until STDOUT becomes writable and print something.
73
74			$stdout_ready = AE::io *STDOUT, 1, sub { print STDOUT "woaw\n" };
75
76			=item $w = AE::timer $after, $interval, $cb
77
78			Creates a timer watcher that invokes the callback C<$cb> after at least
79			C<$after> second have passed (C<$after> can be negative or C<0>).
80
81			If C<$interval> is C<0>, then the clalback will only be invoked once,
82			otherwise it must be a positive number of seconds that specified the
83			interval between successive invocations of the callback.
84
85			Example: print "too late" after at least one second has passed.
86
87			$timer_once = AE::timer 1, 0, sub { print "too late\n" };
88
89			Example: print "blubb" once a second, starting as soon as possible.
90
91			$timer_repeated = AE::timer 0, 1, sub { print "blubb\n" };
92
93			=item $w = AE::signal $signame, $cb
94
95			Invoke the callback c<$cb> each time one or more occurences of the named
96			signal C<$signame> are detected.
97
98			=item $w = AE::child $pid, $cb
99
100			Invokes the callbakc C<$cb> when the child with the given C<$pid> exits
101			(or all children, when C<$pid> is zero).
102
103			The callback will get the actual pid and exit status as arguments.
104
105			=item $w = AE::idle $cb
106
107			Invoke the callback C<$cb> each time the event loop is "idle" (has no
108			events outstanding), but do not prevent the event loop from polling for
109			more events.
110
111			=item $cv = AE::cv
112
113			=item $cv = AE::cv { BLOCK }
114
115			Create a new condition variable. The first form is identical to C<<
116			AnyEvent->condvar >>, the second form additionally sets the callback (as
117			if the C<cb> method is called on the condition variable).
118
119			=item AE::now
120
121			Returns the current event loop time (may be cached by the event loop).
122
123			=item AE::now_update
124
125			Ensures that the current event loop time is up to date.
126
127			=item AE::time
128
129			Return the current time (not cached, always consults a hardware clock).
130
131			=back
132	root	1.1
133			=head1 AUTHOR
134
135			Marc Lehmann <schmorp@schmorp.de>
136			http://home.schmorp.de/
137
138			=cut
139
140	root	1.2	1
141