… | |
… | |
2 | AnyEvent - provide framework for multiple event loops |
2 | AnyEvent - provide framework for multiple event loops |
3 | |
3 | |
4 | Event, Coro, Glib, Tk - various supported event loops |
4 | Event, Coro, Glib, Tk - various supported event loops |
5 | |
5 | |
6 | SYNOPSIS |
6 | SYNOPSIS |
7 | use AnyEvent; |
7 | use AnyEvent; |
8 | |
8 | |
9 | my $w = AnyEvent->io (fh => ..., poll => "[rw]+", cb => sub { |
9 | my $w = AnyEvent->io (fh => ..., poll => "[rw]+", cb => sub { |
10 | my ($poll_got) = @_; |
10 | my ($poll_got) = @_; |
11 | ... |
11 | ... |
12 | }); |
12 | }); |
13 | |
13 | |
14 | - only one io watcher per $fh and $poll type is allowed (i.e. on a |
14 | * only one io watcher per $fh and $poll type is allowed (i.e. on a |
15 | socket you can have one r + one w or one rw watcher, not any more. |
15 | socket you can have one r + one w or one rw watcher, not any more |
|
|
16 | (limitation by Tk). |
16 | |
17 | |
|
|
18 | * the $poll_got passed to the handler needs to be checked by looking for |
|
|
19 | single characters (e.g. with a regex), as it can contain more event |
|
|
20 | types than were requested (e.g. a 'w' watcher might generate 'rw' |
|
|
21 | events, limitation by Glib). |
|
|
22 | |
17 | - AnyEvent will keep filehandles alive, so as long as the watcher |
23 | * AnyEvent will keep filehandles alive, so as long as the watcher |
18 | exists, the filehandle exists. |
24 | exists, the filehandle exists. |
19 | |
25 | |
20 | my $w = AnyEvent->timer (after => $seconds, cb => sub { |
26 | my $w = AnyEvent->timer (after => $seconds, cb => sub { |
21 | ... |
27 | ... |
22 | }); |
28 | }); |
23 | |
29 | |
24 | - io and time watchers get canceled whenever $w is destroyed, so keep a |
30 | * io and time watchers get canceled whenever $w is destroyed, so keep a |
25 | copy |
31 | copy |
26 | |
32 | |
27 | - timers can only be used once and must be recreated for repeated |
33 | * timers can only be used once and must be recreated for repeated |
28 | operation |
34 | operation (limitation by Glib and Tk). |
29 | |
35 | |
30 | my $w = AnyEvent->condvar; # kind of main loop replacement |
36 | my $w = AnyEvent->condvar; # kind of main loop replacement |
31 | $w->wait; # enters main loop till $condvar gets ->broadcast |
37 | $w->wait; # enters main loop till $condvar gets ->broadcast |
32 | $w->broadcast; # wake up current and all future wait's |
38 | $w->broadcast; # wake up current and all future wait's |
33 | |
39 | |
34 | - condvars are used to give blocking behaviour when neccessary. Create a |
40 | * condvars are used to give blocking behaviour when neccessary. Create a |
35 | condvar for any "request" or "event" your module might create, |
41 | condvar for any "request" or "event" your module might create, |
36 | "->broadcast" it when the event happens and provide a function that |
42 | "->broadcast" it when the event happens and provide a function that |
37 | calls "->wait" for it. See the examples below. |
43 | calls "->wait" for it. See the examples below. |
38 | |
44 | |
39 | DESCRIPTION |
45 | DESCRIPTION |
… | |
… | |
50 | modules is loaded: Coro::Event, Event, Glib, Tk. The first one found is |
56 | modules is loaded: Coro::Event, Event, Glib, Tk. The first one found is |
51 | used. If none is found, the module tries to load these modules in the |
57 | used. If none is found, the module tries to load these modules in the |
52 | order given. The first one that could be successfully loaded will be |
58 | order given. The first one that could be successfully loaded will be |
53 | used. If still none could be found, it will issue an error. |
59 | used. If still none could be found, it will issue an error. |
54 | |
60 | |
|
|
61 | SUPPLYING YOUR OWN EVENT MODEL INTERFACE |
|
|
62 | If you need to support another event library which isn't directly |
|
|
63 | supported by AnyEvent, you can supply your own interface to it by |
|
|
64 | pushing, before the first watch gets created, the package name of the |
|
|
65 | event module and the package name of the interface to use onto |
|
|
66 | @AnyEvent::REGISTRY. You can do that before and even without loading |
|
|
67 | AnyEvent. |
|
|
68 | |
|
|
69 | Example: |
|
|
70 | |
|
|
71 | push @AnyEvent::REGISTRY, [urxvt => urxvt::anyevent::]; |
|
|
72 | |
|
|
73 | This tells AnyEvent to (literally) use the "urxvt::anyevent::" module |
|
|
74 | when it finds the "urxvt" module is loaded. When AnyEvent is loaded and |
|
|
75 | requested to find a suitable event model, it will first check for the |
|
|
76 | urxvt module. |
|
|
77 | |
|
|
78 | The above isn't fictitious, the *rxvt-unicode* (a.k.a. urxvt) uses the |
|
|
79 | above line exactly. An interface isn't included in AnyEvent because it |
|
|
80 | doesn't make sense outside the embedded interpreter inside |
|
|
81 | *rxvt-unicode*, and it is updated and maintained as part of the |
|
|
82 | *rxvt-unicode* distribution. |
|
|
83 | |
|
|
84 | ENVIRONMENT VARIABLES |
|
|
85 | The following environment variables are used by this module: |
|
|
86 | |
|
|
87 | "PERL_ANYEVENT_VERBOSE" when set to 2 or higher, reports which event |
|
|
88 | model gets used. |
|
|
89 | |
55 | EXAMPLE |
90 | EXAMPLE |
56 | The following program uses an io watcher to read data from stdin, a |
91 | The following program uses an io watcher to read data from stdin, a |
57 | timer to display a message once per second, and a condvar to exit the |
92 | timer to display a message once per second, and a condvar to exit the |
58 | program when the user enters quit: |
93 | program when the user enters quit: |
59 | |
94 | |
… | |
… | |
116 | connect $txn->{fh}, ... |
151 | connect $txn->{fh}, ... |
117 | and !$!{EWOULDBLOCK} |
152 | and !$!{EWOULDBLOCK} |
118 | and !$!{EINPROGRESS} |
153 | and !$!{EINPROGRESS} |
119 | and Carp::croak "unable to connect: $!\n"; |
154 | and Carp::croak "unable to connect: $!\n"; |
120 | |
155 | |
121 | Then it creates a write-watcher which gets called wehnever an error |
156 | Then it creates a write-watcher which gets called whenever an error |
122 | occurs or the connection succeeds: |
157 | occurs or the connection succeeds: |
123 | |
158 | |
124 | $txn->{w} = AnyEvent->io (fh => $txn->{fh}, poll => 'w', cb => sub { $txn->fh_ready_w }); |
159 | $txn->{w} = AnyEvent->io (fh => $txn->{fh}, poll => 'w', cb => sub { $txn->fh_ready_w }); |
125 | |
160 | |
126 | And returns this transaction object. The "fh_ready_w" callback gets |
161 | And returns this transaction object. The "fh_ready_w" callback gets |
… | |
… | |
143 | sysread $txn->{fh}, $txn->{buf}, length $txn->{$buf}; |
178 | sysread $txn->{fh}, $txn->{buf}, length $txn->{$buf}; |
144 | |
179 | |
145 | if (end-of-file or data complete) { |
180 | if (end-of-file or data complete) { |
146 | $txn->{result} = $txn->{buf}; |
181 | $txn->{result} = $txn->{buf}; |
147 | $txn->{finished}->broadcast; |
182 | $txn->{finished}->broadcast; |
|
|
183 | $txb->{cb}->($txn) of $txn->{cb}; # also call callback |
148 | } |
184 | } |
149 | |
185 | |
150 | The "result" method, finally, just waits for the finished signal (if the |
186 | The "result" method, finally, just waits for the finished signal (if the |
151 | request was already finished, it doesn't wait, of course, and returns |
187 | request was already finished, it doesn't wait, of course, and returns |
152 | the data: |
188 | the data: |
153 | |
189 | |
154 | $txn->{finished}->wait; |
190 | $txn->{finished}->wait; |
155 | return $txn->{buf}; |
191 | return $txn->{result}; |
156 | |
192 | |
157 | The actual code goes further and collects all errors ("die"s, |
193 | The actual code goes further and collects all errors ("die"s, |
158 | exceptions) that occured during request processing. The "result" method |
194 | exceptions) that occured during request processing. The "result" method |
159 | detects wether an exception as thrown (it is stored inside the $txn |
195 | detects wether an exception as thrown (it is stored inside the $txn |
160 | object) and just throws the exception, which means connection errors and |
196 | object) and just throws the exception, which means connection errors and |