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2 | EV - perl interface to libev, a high performance full-featured event |
2 | EV - perl interface to libev, a high performance full-featured event |
3 | loop |
3 | loop |
4 | |
4 | |
5 | SYNOPSIS |
5 | SYNOPSIS |
6 | use EV; |
6 | use EV; |
7 | |
7 | |
8 | # TIMERS |
8 | # TIMERS |
9 | |
9 | |
10 | my $w = EV::timer 2, 0, sub { |
10 | my $w = EV::timer 2, 0, sub { |
11 | warn "is called after 2s"; |
11 | warn "is called after 2s"; |
12 | }; |
12 | }; |
13 | |
13 | |
14 | my $w = EV::timer 2, 2, sub { |
14 | my $w = EV::timer 2, 2, sub { |
15 | warn "is called roughly every 2s (repeat = 2)"; |
15 | warn "is called roughly every 2s (repeat = 2)"; |
16 | }; |
16 | }; |
17 | |
17 | |
18 | undef $w; # destroy event watcher again |
18 | undef $w; # destroy event watcher again |
19 | |
19 | |
20 | my $w = EV::periodic 0, 60, 0, sub { |
20 | my $w = EV::periodic 0, 60, 0, sub { |
21 | warn "is called every minute, on the minute, exactly"; |
21 | warn "is called every minute, on the minute, exactly"; |
22 | }; |
22 | }; |
23 | |
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24 | # IO |
23 | |
25 | |
24 | # IO |
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25 | |
26 | my $w = EV::io *STDIN, EV::READ, sub { |
26 | my $w = EV::io *STDIN, EV::READ, sub { |
27 | my ($w, $revents) = @_; # all callbacks receive the watcher and event mask |
27 | my ($w, $revents) = @_; # all callbacks receive the watcher and event mask |
28 | warn "stdin is readable, you entered: ", <STDIN>; |
28 | warn "stdin is readable, you entered: ", <STDIN>; |
29 | }; |
29 | }; |
30 | |
30 | |
31 | # SIGNALS |
31 | # SIGNALS |
32 | |
32 | |
33 | my $w = EV::signal 'QUIT', sub { |
33 | my $w = EV::signal 'QUIT', sub { |
34 | warn "sigquit received\n"; |
34 | warn "sigquit received\n"; |
35 | }; |
35 | }; |
36 | |
36 | |
37 | # CHILD/PID STATUS CHANGES |
37 | # CHILD/PID STATUS CHANGES |
38 | |
38 | |
39 | my $w = EV::child 666, sub { |
39 | my $w = EV::child 666, 0, sub { |
40 | my ($w, $revents) = @_; |
40 | my ($w, $revents) = @_; |
41 | my $status = $w->rstatus; |
41 | my $status = $w->rstatus; |
42 | }; |
42 | }; |
43 | |
43 | |
44 | # STAT CHANGES |
44 | # STAT CHANGES |
45 | my $w = EV::stat "/etc/passwd", 10, sub { |
45 | my $w = EV::stat "/etc/passwd", 10, sub { |
46 | my ($w, $revents) = @_; |
46 | my ($w, $revents) = @_; |
47 | warn $w->path, " has changed somehow.\n"; |
47 | warn $w->path, " has changed somehow.\n"; |
48 | }; |
48 | }; |
49 | |
49 | |
50 | # MAINLOOP |
50 | # MAINLOOP |
51 | EV::loop; # loop until EV::unloop is called or all watchers stop |
51 | EV::loop; # loop until EV::unloop is called or all watchers stop |
52 | EV::loop EV::LOOP_ONESHOT; # block until at least one event could be handled |
52 | EV::loop EV::LOOP_ONESHOT; # block until at least one event could be handled |
53 | EV::loop EV::LOOP_NONBLOCK; # try to handle same events, but do not block |
53 | EV::loop EV::LOOP_NONBLOCK; # try to handle same events, but do not block |
54 | |
54 | |
55 | DESCRIPTION |
55 | DESCRIPTION |
56 | This module provides an interface to libev |
56 | This module provides an interface to libev |
57 | (<http://software.schmorp.de/pkg/libev.html>). While the documentation |
57 | (<http://software.schmorp.de/pkg/libev.html>). While the documentation |
58 | below is comprehensive, one might also consult the documentation of |
58 | below is comprehensive, one might also consult the documentation of |
59 | libev itself (<http://cvs.schmorp.de/libev/ev.html>) for more subtle |
59 | libev itself (<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod>) |
60 | details on watcher semantics or some discussion on the available |
60 | for more subtle details on watcher semantics or some discussion on the |
61 | backends, or how to force a specific backend with "LIBEV_FLAGS", or just |
61 | available backends, or how to force a specific backend with |
62 | about in any case because it has much more detailed information. |
62 | "LIBEV_FLAGS", or just about in any case because it has much more |
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63 | detailed information. |
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64 | |
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65 | This module is very fast and scalable. It is actually so fast that you |
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66 | can use it through the AnyEvent module, stay portable to other event |
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67 | loops (if you don't rely on any watcher types not available through it) |
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68 | and still be faster than with any other event loop currently supported |
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69 | in Perl. |
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70 | |
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71 | EVENT LOOPS |
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72 | EV supports multiple event loops: There is a single "default event loop" |
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73 | that can handle everything including signals and child watchers, and any |
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74 | number of "dynamic event loops" that can use different backends (with |
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75 | various limitations), but no child and signal watchers. |
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76 | |
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77 | You do not have to do anything to create the default event loop: When |
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78 | the module is loaded a suitable backend is selected on the premise of |
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79 | selecting a working backend (which for example rules out kqueue on most |
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80 | BSDs). Modules should, unless they have "special needs" always use the |
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81 | default loop as this is fastest (perl-wise), best supported by other |
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82 | modules (e.g. AnyEvent or Coro) and most portable event loop. |
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83 | |
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84 | For specific programs you can create additional event loops dynamically. |
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85 | |
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86 | $loop = new EV::loop [$flags] |
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87 | Create a new event loop as per the specified flags. Please refer to |
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88 | the "ev_loop_new ()" function description in the libev documentation |
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89 | (<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#GLOBAL_FUNCTI |
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90 | ONS>) for more info. |
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91 | |
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92 | The loop will automatically be destroyed when it is no longer |
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93 | referenced by any watcher and the loop object goes out of scope. |
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94 | |
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95 | Using "EV::FLAG_FORKCHECK" is recommended, as only the default event |
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96 | loop is protected by this module. |
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97 | |
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98 | $loop->loop_fork |
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99 | Must be called after a fork in the child, before entering or |
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100 | continuing the event loop. An alternative is to use |
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101 | "EV::FLAG_FORKCHECK" which calls this fucntion automatically, at |
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102 | some performance loss (refer to the libev documentation). |
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103 | |
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104 | $loop = EV::default_loop [$flags] |
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105 | Return the default loop (which is a singleton object). |
63 | |
106 | |
64 | BASIC INTERFACE |
107 | BASIC INTERFACE |
65 | $EV::DIED |
108 | $EV::DIED |
66 | Must contain a reference to a function that is called when a |
109 | Must contain a reference to a function that is called when a |
67 | callback throws an exception (with $@ containing thr error). The |
110 | callback throws an exception (with $@ containing the error). The |
68 | default prints an informative message and continues. |
111 | default prints an informative message and continues. |
69 | |
112 | |
70 | If this callback throws an exception it will be silently ignored. |
113 | If this callback throws an exception it will be silently ignored. |
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114 | |
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115 | $flags = EV::supported_backends |
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116 | $flags = EV::recommended_backends |
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117 | $flags = EV::embeddable_backends |
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118 | Returns the set (see "EV::BACKEND_*" flags) of backends supported by |
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119 | this instance of EV, the set of recommended backends (supposed to be |
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120 | good) for this platform and the set of embeddable backends (see |
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121 | EMBED WATCHERS). |
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122 | |
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123 | EV::sleep $seconds |
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124 | Block the process for the given number of (fractional) seconds. |
71 | |
125 | |
72 | $time = EV::time |
126 | $time = EV::time |
73 | Returns the current time in (fractional) seconds since the epoch. |
127 | Returns the current time in (fractional) seconds since the epoch. |
74 | |
128 | |
75 | $time = EV::now |
129 | $time = EV::now |
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130 | $time = $loop->now |
76 | Returns the time the last event loop iteration has been started. |
131 | Returns the time the last event loop iteration has been started. |
77 | This is the time that (relative) timers are based on, and refering |
132 | This is the time that (relative) timers are based on, and refering |
78 | to it is usually faster then calling EV::time. |
133 | to it is usually faster then calling EV::time. |
79 | |
134 | |
80 | $method = EV::method |
135 | $backend = EV::backend |
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136 | $backend = $loop->backend |
81 | Returns an integer describing the backend used by libev |
137 | Returns an integer describing the backend used by libev |
82 | (EV::METHOD_SELECT or EV::METHOD_EPOLL). |
138 | (EV::METHOD_SELECT or EV::METHOD_EPOLL). |
83 | |
139 | |
84 | EV::loop [$flags] |
140 | EV::loop [$flags] |
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141 | $loop->loop ([$flags]) |
85 | Begin checking for events and calling callbacks. It returns when a |
142 | Begin checking for events and calling callbacks. It returns when a |
86 | callback calls EV::unloop. |
143 | callback calls EV::unloop. |
87 | |
144 | |
88 | The $flags argument can be one of the following: |
145 | The $flags argument can be one of the following: |
89 | |
146 | |
90 | 0 as above |
147 | 0 as above |
91 | EV::LOOP_ONESHOT block at most once (wait, but do not loop) |
148 | EV::LOOP_ONESHOT block at most once (wait, but do not loop) |
92 | EV::LOOP_NONBLOCK do not block at all (fetch/handle events but do not wait) |
149 | EV::LOOP_NONBLOCK do not block at all (fetch/handle events but do not wait) |
93 | |
150 | |
94 | EV::unloop [$how] |
151 | EV::unloop [$how] |
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152 | $loop->unloop ([$how]) |
95 | When called with no arguments or an argument of EV::UNLOOP_ONE, |
153 | When called with no arguments or an argument of EV::UNLOOP_ONE, |
96 | makes the innermost call to EV::loop return. |
154 | makes the innermost call to EV::loop return. |
97 | |
155 | |
98 | When called with an argument of EV::UNLOOP_ALL, all calls to |
156 | When called with an argument of EV::UNLOOP_ALL, all calls to |
99 | EV::loop will return as fast as possible. |
157 | EV::loop will return as fast as possible. |
100 | |
158 | |
101 | $count = EV::loop_count |
159 | $count = EV::loop_count |
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160 | $count = $loop->loop_count |
102 | Return the number of times the event loop has polled for new events. |
161 | Return the number of times the event loop has polled for new events. |
103 | Sometiems useful as a generation counter. |
162 | Sometiems useful as a generation counter. |
104 | |
163 | |
105 | EV::once $fh_or_undef, $events, $timeout, $cb->($revents) |
164 | EV::once $fh_or_undef, $events, $timeout, $cb->($revents) |
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165 | $loop->once ($fh_or_undef, $events, $timeout, $cb->($revents)) |
106 | This function rolls together an I/O and a timer watcher for a single |
166 | This function rolls together an I/O and a timer watcher for a single |
107 | one-shot event without the need for managing a watcher object. |
167 | one-shot event without the need for managing a watcher object. |
108 | |
168 | |
109 | If $fh_or_undef is a filehandle or file descriptor, then $events |
169 | If $fh_or_undef is a filehandle or file descriptor, then $events |
110 | must be a bitset containing either "EV::READ", "EV::WRITE" or |
170 | must be a bitset containing either "EV::READ", "EV::WRITE" or |
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115 | If timeout is "undef" or negative, then there will be no timeout. |
175 | If timeout is "undef" or negative, then there will be no timeout. |
116 | Otherwise a EV::timer with this value will be started. |
176 | Otherwise a EV::timer with this value will be started. |
117 | |
177 | |
118 | When an error occurs or either the timeout or I/O watcher triggers, |
178 | When an error occurs or either the timeout or I/O watcher triggers, |
119 | then the callback will be called with the received event set (in |
179 | then the callback will be called with the received event set (in |
120 | general you can expect it to be a combination of "EV:ERROR", |
180 | general you can expect it to be a combination of "EV::ERROR", |
121 | "EV::READ", "EV::WRITE" and "EV::TIMEOUT"). |
181 | "EV::READ", "EV::WRITE" and "EV::TIMEOUT"). |
122 | |
182 | |
123 | EV::once doesn't return anything: the watchers stay active till |
183 | EV::once doesn't return anything: the watchers stay active till |
124 | either of them triggers, then they will be stopped and freed, and |
184 | either of them triggers, then they will be stopped and freed, and |
125 | the callback invoked. |
185 | the callback invoked. |
126 | |
186 | |
127 | EV::feed_fd_event ($fd, $revents) |
187 | EV::feed_fd_event ($fd, $revents) |
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188 | $loop->feed_fd_event ($fd, $revents) |
128 | Feed an event on a file descriptor into EV. EV will react to this |
189 | Feed an event on a file descriptor into EV. EV will react to this |
129 | call as if the readyness notifications specified by $revents (a |
190 | call as if the readyness notifications specified by $revents (a |
130 | combination of "EV::READ" and "EV::WRITE") happened on the file |
191 | combination of "EV::READ" and "EV::WRITE") happened on the file |
131 | descriptor $fd. |
192 | descriptor $fd. |
132 | |
193 | |
133 | EV::feed_signal_event ($signal) |
194 | EV::feed_signal_event ($signal) |
134 | Feed a signal event into EV. EV will react to this call as if the |
195 | Feed a signal event into EV. EV will react to this call as if the |
135 | signal specified by $signal had occured. |
196 | signal specified by $signal had occured. |
136 | |
197 | |
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198 | EV::set_io_collect_interval $time |
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199 | $loop->set_io_collect_interval ($time) |
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200 | EV::set_timeout_collect_interval $time |
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201 | $loop->set_timeout_collect_interval ($time) |
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202 | These advanced functions set the minimum block interval when polling |
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203 | for I/O events and the minimum wait interval for timer events. See |
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204 | the libev documentation at |
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205 | <http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#FUNCTIONS_CONT |
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206 | ROLLING_THE_EVENT_LOOP> for a more detailed discussion. |
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207 | |
137 | WATCHER OBJECTS |
208 | WATCHER OBJECTS |
138 | A watcher is an object that gets created to record your interest in some |
209 | A watcher is an object that gets created to record your interest in some |
139 | event. For instance, if you want to wait for STDIN to become readable, |
210 | event. For instance, if you want to wait for STDIN to become readable, |
140 | you would create an EV::io watcher for that: |
211 | you would create an EV::io watcher for that: |
141 | |
212 | |
142 | my $watcher = EV::io *STDIN, EV::READ, sub { |
213 | my $watcher = EV::io *STDIN, EV::READ, sub { |
143 | my ($watcher, $revents) = @_; |
214 | my ($watcher, $revents) = @_; |
144 | warn "yeah, STDIN should not be readable without blocking!\n" |
215 | warn "yeah, STDIN should now be readable without blocking!\n" |
145 | }; |
216 | }; |
146 | |
217 | |
147 | All watchers can be active (waiting for events) or inactive (paused). |
218 | All watchers can be active (waiting for events) or inactive (paused). |
148 | Only active watchers will have their callbacks invoked. All callbacks |
219 | Only active watchers will have their callbacks invoked. All callbacks |
149 | will be called with at least two arguments: the watcher and a bitmask of |
220 | will be called with at least two arguments: the watcher and a bitmask of |
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220 | $w->feed_event ($revents) |
291 | $w->feed_event ($revents) |
221 | Feed some events on this watcher into EV. EV will react to this call |
292 | Feed some events on this watcher into EV. EV will react to this call |
222 | as if the watcher had received the given $revents mask. |
293 | as if the watcher had received the given $revents mask. |
223 | |
294 | |
224 | $revents = $w->clear_pending |
295 | $revents = $w->clear_pending |
225 | If the watcher is pending, this function returns clears its pending |
296 | If the watcher is pending, this function clears its pending status |
226 | status and returns its $revents bitset (as if its callback was |
297 | and returns its $revents bitset (as if its callback was invoked). If |
227 | invoked). If the watcher isn't pending it does nothing and returns |
298 | the watcher isn't pending it does nothing and returns 0. |
228 | 0. |
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229 | |
299 | |
230 | $previous_state = $w->keepalive ($bool) |
300 | $previous_state = $w->keepalive ($bool) |
231 | Normally, "EV::loop" will return when there are no active watchers |
301 | Normally, "EV::loop" will return when there are no active watchers |
232 | (which is a "deadlock" because no progress can be made anymore). |
302 | (which is a "deadlock" because no progress can be made anymore). |
233 | This is convinient because it allows you to start your watchers (and |
303 | This is convinient because it allows you to start your watchers (and |
234 | your jobs), call "EV::loop" once and when it returns you know that |
304 | your jobs), call "EV::loop" once and when it returns you know that |
235 | all your jobs are finished (or they forgot to register some watchers |
305 | all your jobs are finished (or they forgot to register some watchers |
236 | for their task :). |
306 | for their task :). |
237 | |
307 | |
238 | Sometimes, however, this gets in your way, for example when you the |
308 | Sometimes, however, this gets in your way, for example when the |
239 | module that calls "EV::loop" (usually the main program) is not the |
309 | module that calls "EV::loop" (usually the main program) is not the |
240 | same module as a long-living watcher (for example a DNS client |
310 | same module as a long-living watcher (for example a DNS client |
241 | module written by somebody else even). Then you might want any |
311 | module written by somebody else even). Then you might want any |
242 | outstanding requests to be handled, but you would not want to keep |
312 | outstanding requests to be handled, but you would not want to keep |
243 | "EV::loop" from returning just because you happen to have this |
313 | "EV::loop" from returning just because you happen to have this |
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253 | Example: Register an I/O watcher for some UDP socket but do not keep |
323 | Example: Register an I/O watcher for some UDP socket but do not keep |
254 | the event loop from running just because of that watcher. |
324 | the event loop from running just because of that watcher. |
255 | |
325 | |
256 | my $udp_socket = ... |
326 | my $udp_socket = ... |
257 | my $udp_watcher = EV::io $udp_socket, EV::READ, sub { ... }; |
327 | my $udp_watcher = EV::io $udp_socket, EV::READ, sub { ... }; |
258 | $udp_watcher->keepalive (0); |
328 | $1000udp_watcher->keepalive (0); |
259 | |
329 | |
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330 | $loop = $w->loop |
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331 | Return the loop that this watcher is attached to. |
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332 | |
260 | WATCHER TYPES |
333 | WATCHER TYPES |
261 | Each of the following subsections describes a single watcher type. |
334 | Each of the following subsections describes a single watcher type. |
262 | |
335 | |
263 | I/O WATCHERS - is this file descriptor readable or writable? |
336 | I/O WATCHERS - is this file descriptor readable or writable? |
264 | $w = EV::io $fileno_or_fh, $eventmask, $callback |
337 | $w = EV::io $fileno_or_fh, $eventmask, $callback |
265 | $w = EV::io_ns $fileno_or_fh, $eventmask, $callback |
338 | $w = EV::io_ns $fileno_or_fh, $eventmask, $callback |
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339 | $w = $loop->io ($fileno_or_fh, $eventmask, $callback) |
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340 | $w = $loop->io_ns ($fileno_or_fh, $eventmask, $callback) |
266 | As long as the returned watcher object is alive, call the $callback |
341 | As long as the returned watcher object is alive, call the $callback |
267 | when at least one of events specified in $eventmask occurs. |
342 | when at least one of events specified in $eventmask occurs. |
268 | |
343 | |
269 | The $eventmask can be one or more of these constants ORed together: |
344 | The $eventmask can be one or more of these constants ORed together: |
270 | |
345 | |
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287 | Returns the previously set event mask and optionally set a new one. |
362 | Returns the previously set event mask and optionally set a new one. |
288 | |
363 | |
289 | TIMER WATCHERS - relative and optionally repeating timeouts |
364 | TIMER WATCHERS - relative and optionally repeating timeouts |
290 | $w = EV::timer $after, $repeat, $callback |
365 | $w = EV::timer $after, $repeat, $callback |
291 | $w = EV::timer_ns $after, $repeat, $callback |
366 | $w = EV::timer_ns $after, $repeat, $callback |
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367 | $w = $loop->timer ($after, $repeat, $callback) |
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368 | $w = $loop->timer_ns ($after, $repeat, $callback) |
292 | Calls the callback after $after seconds (which may be fractional). |
369 | Calls the callback after $after seconds (which may be fractional). |
293 | If $repeat is non-zero, the timer will be restarted (with the |
370 | If $repeat is non-zero, the timer will be restarted (with the |
294 | $repeat value as $after) after the callback returns. |
371 | $repeat value as $after) after the callback returns. |
295 | |
372 | |
296 | This means that the callback would be called roughly after $after |
373 | This means that the callback would be called roughly after $after |
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332 | method on the timeout. |
409 | method on the timeout. |
333 | |
410 | |
334 | PERIODIC WATCHERS - to cron or not to cron? |
411 | PERIODIC WATCHERS - to cron or not to cron? |
335 | $w = EV::periodic $at, $interval, $reschedule_cb, $callback |
412 | $w = EV::periodic $at, $interval, $reschedule_cb, $callback |
336 | $w = EV::periodic_ns $at, $interval, $reschedule_cb, $callback |
413 | $w = EV::periodic_ns $at, $interval, $reschedule_cb, $callback |
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414 | $w = $loop->periodic ($at, $interval, $reschedule_cb, $callback) |
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415 | $w = $loop->periodic_ns ($at, $interval, $reschedule_cb, $callback) |
337 | Similar to EV::timer, but is not based on relative timeouts but on |
416 | Similar to EV::timer, but is not based on relative timeouts but on |
338 | absolute times. Apart from creating "simple" timers that trigger |
417 | absolute times. Apart from creating "simple" timers that trigger |
339 | "at" the specified time, it can also be used for non-drifting |
418 | "at" the specified time, it can also be used for non-drifting |
340 | absolute timers and more complex, cron-like, setups that are not |
419 | absolute timers and more complex, cron-like, setups that are not |
341 | adversely affected by time jumps (i.e. when the system clock is |
420 | adversely affected by time jumps (i.e. when the system clock is |
342 | changed by explicit date -s or other means such as ntpd). It is also |
421 | changed by explicit date -s or other means such as ntpd). It is also |
343 | the most complex watcher type in EV. |
422 | the most complex watcher type in EV. |
344 | |
423 | |
345 | It has three distinct "modes": |
424 | It has three distinct "modes": |
346 | |
425 | |
347 | * absolute timer ($interval = $reschedule_cb = 0) |
426 | * absolute timer ($interval = $reschedule_cb = 0) |
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427 | |
348 | This time simply fires at the wallclock time $at and doesn't |
428 | This time simply fires at the wallclock time $at and doesn't |
349 | repeat. It will not adjust when a time jump occurs, that is, if |
429 | repeat. It will not adjust when a time jump occurs, that is, if |
350 | it is to be run at January 1st 2011 then it will run when the |
430 | it is to be run at January 1st 2011 then it will run when the |
351 | system time reaches or surpasses this time. |
431 | system time reaches or surpasses this time. |
352 | |
432 | |
353 | * non-repeating interval timer ($interval > 0, $reschedule_cb = 0) |
433 | * repeating interval timer ($interval > 0, $reschedule_cb = 0) |
|
|
434 | |
354 | In this mode the watcher will always be scheduled to time out at |
435 | In this mode the watcher will always be scheduled to time out at |
355 | the next "$at + N * $interval" time (for some integer N) and |
436 | the next "$at + N * $interval" time (for some integer N) and |
356 | then repeat, regardless of any time jumps. |
437 | then repeat, regardless of any time jumps. |
357 | |
438 | |
358 | This can be used to create timers that do not drift with respect |
439 | This can be used to create timers that do not drift with respect |
… | |
… | |
367 | Another way to think about it (for the mathematically inclined) |
448 | Another way to think about it (for the mathematically inclined) |
368 | is that EV::periodic will try to run the callback in this mode |
449 | is that EV::periodic will try to run the callback in this mode |
369 | at the next possible time where "$time = $at (mod $interval)", |
450 | at the next possible time where "$time = $at (mod $interval)", |
370 | regardless of any time jumps. |
451 | regardless of any time jumps. |
371 | |
452 | |
372 | * manual reschedule mode ($reschedule_cb = coderef) |
453 | * manual reschedule mode ($reschedule_cb = coderef) |
|
|
454 | |
373 | In this mode $interval and $at are both being ignored. Instead, |
455 | In this mode $interval and $at are both being ignored. Instead, |
374 | each time the periodic watcher gets scheduled, the reschedule |
456 | each time the periodic watcher gets scheduled, the reschedule |
375 | callback ($reschedule_cb) will be called with the watcher as |
457 | callback ($reschedule_cb) will be called with the watcher as |
376 | first, and the current time as second argument. |
458 | first, and the current time as second argument. |
377 | |
459 | |
378 | *This callback MUST NOT stop or destroy this or any other |
460 | *This callback MUST NOT stop or destroy this or any other |
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|
461 | periodic watcher, ever, and MUST NOT call any event loop |
379 | periodic watcher, ever*. If you need to stop it, return 1e30 and |
462 | functions or methods*. If you need to stop it, return 1e30 and |
380 | stop it afterwards. |
463 | stop it afterwards. You may create and start a "EV::prepare" |
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|
464 | watcher for this task. |
381 | |
465 | |
382 | It must return the next time to trigger, based on the passed |
466 | It must return the next time to trigger, based on the passed |
383 | time value (that is, the lowest time value larger than to the |
467 | time value (that is, the lowest time value larger than or equal |
384 | second argument). It will usually be called just before the |
468 | to to the second argument). It will usually be called just |
385 | callback will be triggered, but might be called at other times, |
469 | before the callback will be triggered, but might be called at |
386 | too. |
470 | other times, too. |
387 | |
471 | |
388 | This can be used to create very complex timers, such as a timer |
472 | This can be used to create very complex timers, such as a timer |
389 | that triggers on each midnight, local time (actually 24 hours |
473 | that triggers on each midnight, local time (actually 24 hours |
390 | after the last midnight, to keep the example simple. If you know |
474 | after the last midnight, to keep the example simple. If you know |
391 | a way to do it correctly in about the same space (without |
475 | a way to do it correctly in about the same space (without |
… | |
… | |
409 | be called at any time. |
493 | be called at any time. |
410 | |
494 | |
411 | $w->again |
495 | $w->again |
412 | Simply stops and starts the watcher again. |
496 | Simply stops and starts the watcher again. |
413 | |
497 | |
|
|
498 | $time = $w->at |
|
|
499 | Return the time that the watcher is expected to trigger next. |
|
|
500 | |
414 | SIGNAL WATCHERS - signal me when a signal gets signalled! |
501 | SIGNAL WATCHERS - signal me when a signal gets signalled! |
415 | $w = EV::signal $signal, $callback |
502 | $w = EV::signal $signal, $callback |
416 | $w = EV::signal_ns $signal, $callback |
503 | $w = EV::signal_ns $signal, $callback |
417 | Call the callback when $signal is received (the signal can be |
504 | Call the callback when $signal is received (the signal can be |
418 | specified by number or by name, just as with "kill" or %SIG). |
505 | specified by number or by name, just as with "kill" or %SIG). |
… | |
… | |
435 | $old_signum = $w->signal ($new_signal) |
522 | $old_signum = $w->signal ($new_signal) |
436 | Returns the previously set signal (always as a number not name) and |
523 | Returns the previously set signal (always as a number not name) and |
437 | optionally set a new one. |
524 | optionally set a new one. |
438 | |
525 | |
439 | CHILD WATCHERS - watch out for process status changes |
526 | CHILD WATCHERS - watch out for process status changes |
440 | $w = EV::child $pid, $callback |
527 | $w = EV::child $pid, $trace, $callback |
441 | $w = EV::child_ns $pid, $callback |
528 | $w = EV::child_ns $pid, $trace, $callback |
|
|
529 | $w = $loop->child ($pid, $trace, $callback) |
|
|
530 | $w = $loop->child_ns ($pid, $trace, $callback) |
442 | Call the callback when a status change for pid $pid (or any pid if |
531 | Call the callback when a status change for pid $pid (or any pid if |
443 | $pid is 0) has been received. More precisely: when the process |
532 | $pid is 0) has been received (a status change happens when the |
|
|
533 | process terminates or is killed, or, when trace is true, |
|
|
534 | additionally when it is stopped or continued). More precisely: when |
444 | receives a "SIGCHLD", EV will fetch the outstanding exit/wait status |
535 | the process receives a "SIGCHLD", EV will fetch the outstanding |
445 | for all changed/zombie children and call the callback. |
536 | exit/wait status for all changed/zombie children and call the |
|
|
537 | callback. |
446 | |
538 | |
447 | It is valid (and fully supported) to install a child watcher after a |
539 | It is valid (and fully supported) to install a child watcher after a |
448 | child has exited but before the event loop has started its next |
540 | child has exited but before the event loop has started its next |
449 | iteration (for example, first you "fork", then the new child process |
541 | iteration (for example, first you "fork", then the new child process |
450 | might exit, and only then do you install a child watcher in the |
542 | might exit, and only then do you install a child watcher in the |
… | |
… | |
457 | be called. |
549 | be called. |
458 | |
550 | |
459 | The "child_ns" variant doesn't start (activate) the newly created |
551 | The "child_ns" variant doesn't start (activate) the newly created |
460 | watcher. |
552 | watcher. |
461 | |
553 | |
462 | $w->set ($pid) |
554 | $w->set ($pid, $trace) |
463 | Reconfigures the watcher, see the constructor above for details. Can |
555 | Reconfigures the watcher, see the constructor above for details. Can |
464 | be called at any time. |
556 | be called at any time. |
465 | |
557 | |
466 | $current_pid = $w->pid |
558 | $current_pid = $w->pid |
467 | $old_pid = $w->pid ($new_pid) |
|
|
468 | Returns the previously set process id and optionally set a new one. |
559 | Returns the previously set process id and optionally set a new one. |
469 | |
560 | |
470 | $exit_status = $w->rstatus |
561 | $exit_status = $w->rstatus |
471 | Return the exit/wait status (as returned by waitpid, see the waitpid |
562 | Return the exit/wait status (as returned by waitpid, see the waitpid |
472 | entry in perlfunc). |
563 | entry in perlfunc). |
… | |
… | |
476 | a watcher for all pids). |
567 | a watcher for all pids). |
477 | |
568 | |
478 | STAT WATCHERS - did the file attributes just change? |
569 | STAT WATCHERS - did the file attributes just change? |
479 | $w = EV::stat $path, $interval, $callback |
570 | $w = EV::stat $path, $interval, $callback |
480 | $w = EV::stat_ns $path, $interval, $callback |
571 | $w = EV::stat_ns $path, $interval, $callback |
|
|
572 | $w = $loop->stat ($path, $interval, $callback) |
|
|
573 | $w = $loop->stat_ns ($path, $interval, $callback) |
481 | Call the callback when a file status change has been detected on |
574 | Call the callback when a file status change has been detected on |
482 | $path. The $path does not need to exist, changing from "path exists" |
575 | $path. The $path does not need to exist, changing from "path exists" |
483 | to "path does not exist" is a status change like any other. |
576 | to "path does not exist" is a status change like any other. |
484 | |
577 | |
485 | The $interval is a recommended polling interval for systems where |
578 | The $interval is a recommended polling interval for systems where |
… | |
… | |
545 | Can be used to query the actual interval used. |
638 | Can be used to query the actual interval used. |
546 | |
639 | |
547 | IDLE WATCHERS - when you've got nothing better to do... |
640 | IDLE WATCHERS - when you've got nothing better to do... |
548 | $w = EV::idle $callback |
641 | $w = EV::idle $callback |
549 | $w = EV::idle_ns $callback |
642 | $w = EV::idle_ns $callback |
|
|
643 | $w = $loop->idle ($callback) |
|
|
644 | $w = $loop->idle_ns ($callback) |
550 | Call the callback when there are no other pending watchers of the |
645 | Call the callback when there are no other pending watchers of the |
551 | same or higher priority (excluding check, prepare and other idle |
646 | same or higher priority (excluding check, prepare and other idle |
552 | watchers of the same or lower priority, of course). They are called |
647 | watchers of the same or lower priority, of course). They are called |
553 | idle watchers because when the watcher is the highest priority |
648 | idle watchers because when the watcher is the highest priority |
554 | pending event in the process, the process is considered to be idle |
649 | pending event in the process, the process is considered to be idle |
… | |
… | |
570 | watcher. |
665 | watcher. |
571 | |
666 | |
572 | PREPARE WATCHERS - customise your event loop! |
667 | PREPARE WATCHERS - customise your event loop! |
573 | $w = EV::prepare $callback |
668 | $w = EV::prepare $callback |
574 | $w = EV::prepare_ns $callback |
669 | $w = EV::prepare_ns $callback |
|
|
670 | $w = $loop->prepare ($callback) |
|
|
671 | $w = $loop->prepare_ns ($callback) |
575 | Call the callback just before the process would block. You can still |
672 | Call the callback just before the process would block. You can still |
576 | create/modify any watchers at this point. |
673 | create/modify any watchers at this point. |
577 | |
674 | |
578 | See the EV::check watcher, below, for explanations and an example. |
675 | See the EV::check watcher, below, for explanations and an example. |
579 | |
676 | |
… | |
… | |
581 | watcher. |
678 | watcher. |
582 | |
679 | |
583 | CHECK WATCHERS - customise your event loop even more! |
680 | CHECK WATCHERS - customise your event loop even more! |
584 | $w = EV::check $callback |
681 | $w = EV::check $callback |
585 | $w = EV::check_ns $callback |
682 | $w = EV::check_ns $callback |
|
|
683 | $w = $loop->check ($callback) |
|
|
684 | $w = $loop->check_ns ($callback) |
586 | Call the callback just after the process wakes up again (after it |
685 | Call the callback just after the process wakes up again (after it |
587 | has gathered events), but before any other callbacks have been |
686 | has gathered events), but before any other callbacks have been |
588 | invoked. |
687 | invoked. |
589 | |
688 | |
590 | This is used to integrate other event-based software into the EV |
689 | This is used to integrate other event-based software into the EV |
… | |
… | |
639 | is done before the event loop blocks next and before "check" watchers |
738 | is done before the event loop blocks next and before "check" watchers |
640 | are being called, and only in the child after the fork. |
739 | are being called, and only in the child after the fork. |
641 | |
740 | |
642 | $w = EV::fork $callback |
741 | $w = EV::fork $callback |
643 | $w = EV::fork_ns $callback |
742 | $w = EV::fork_ns $callback |
|
|
743 | $w = $loop->fork ($callback) |
|
|
744 | $w = $loop->fork_ns ($callback) |
644 | Call the callback before the event loop is resumed in the child |
745 | Call the callback before the event loop is resumed in the child |
645 | process after a fork. |
746 | process after a fork. |
646 | |
747 | |
647 | The "fork_ns" variant doesn't start (activate) the newly created |
748 | The "fork_ns" variant doesn't start (activate) the newly created |
648 | watcher. |
749 | watcher. |
|
|
750 | |
|
|
751 | EMBED WATCHERS - when one backend isn't enough... |
|
|
752 | This is a rather advanced watcher type that lets you embed one event |
|
|
753 | loop into another (currently only IO events are supported in the |
|
|
754 | embedded loop, other types of watchers might be handled in a delayed or |
|
|
755 | incorrect fashion and must not be used). |
|
|
756 | |
|
|
757 | See the libev documentation at |
|
|
758 | <http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#code_ev_embed_code |
|
|
759 | _when_one_backend_> for more details. |
|
|
760 | |
|
|
761 | In short, this watcher is most useful on BSD systems without working |
|
|
762 | kqueue to still be able to handle a large number of sockets: |
|
|
763 | |
|
|
764 | my $socket_loop; |
|
|
765 | |
|
|
766 | # check wether we use SELECT or POLL _and_ KQUEUE is supported |
|
|
767 | if ( |
|
|
768 | (EV::backend & (EV::BACKEND_POLL | EV::BACKEND_SELECT)) |
|
|
769 | && (EV::supported_backends & EV::embeddable_backends & EV::BACKEND_KQUEUE) |
|
|
770 | ) { |
|
|
771 | # use kqueue for sockets |
|
|
772 | $socket_loop = new EV::Loop EV::BACKEND_KQUEUE | EV::FLAG_NOENV; |
|
|
773 | } |
|
|
774 | |
|
|
775 | # use the default loop otherwise |
|
|
776 | $socket_loop ||= EV::default_loop; |
|
|
777 | |
|
|
778 | $w = EV::embed $otherloop, $callback |
|
|
779 | $w = EV::embed_ns $otherloop, $callback |
|
|
780 | $w = $loop->embed ($otherloop, $callback) |
|
|
781 | $w = $loop->embed_ns ($otherloop, $callback) |
|
|
782 | Call the callback when the embedded event loop ($otherloop) has any |
|
|
783 | I/O activity. The $callback should alwas be specified as "undef" in |
|
|
784 | this version of EV, which means the embedded event loop will be |
|
|
785 | managed automatically. |
|
|
786 | |
|
|
787 | The "embed_ns" variant doesn't start (activate) the newly created |
|
|
788 | watcher. |
|
|
789 | |
|
|
790 | ASYNC WATCHERS - how to wake up another event loop |
|
|
791 | Async watchers are provided by EV, but have little use in perl directly, |
|
|
792 | as perl neither supports threads nor direct access to signal handlers or |
|
|
793 | other contexts where they could be of value. |
|
|
794 | |
|
|
795 | It is, however, possible to use them from the XS level. |
|
|
796 | |
|
|
797 | Please see the libev documentation for further details. |
|
|
798 | |
|
|
799 | $w = EV::async $callback |
|
|
800 | $w = EV::async_ns $callback |
|
|
801 | $w->send |
|
|
802 | $bool = $w->async_pending |
649 | |
803 | |
650 | PERL SIGNALS |
804 | PERL SIGNALS |
651 | While Perl signal handling (%SIG) is not affected by EV, the behaviour |
805 | While Perl signal handling (%SIG) is not affected by EV, the behaviour |
652 | with EV is as the same as any other C library: Perl-signals will only be |
806 | with EV is as the same as any other C library: Perl-signals will only be |
653 | handled when Perl runs, which means your signal handler might be invoked |
807 | handled when Perl runs, which means your signal handler might be invoked |
… | |
… | |
660 | to be called on every event loop iteration by installing a "EV::check" |
814 | to be called on every event loop iteration by installing a "EV::check" |
661 | watcher: |
815 | watcher: |
662 | |
816 | |
663 | my $async_check = EV::check sub { }; |
817 | my $async_check = EV::check sub { }; |
664 | |
818 | |
665 | This ensures that perl shortly gets into control for a short time, and |
819 | This ensures that perl gets into control for a short time to handle any |
666 | also ensures slower overall operation. |
820 | pending signals, and also ensures (slightly) slower overall operation. |
667 | |
821 | |
668 | THREADS |
822 | THREADS |
669 | Threads are not supported by this module in any way. Perl pseudo-threads |
823 | Threads are not supported by this module in any way. Perl pseudo-threads |
670 | is evil stuff and must die. As soon as Perl gains real threads I will |
824 | is evil stuff and must die. As soon as Perl gains real threads I will |
671 | work on thread support for it. |
825 | work on thread support for it. |
… | |
… | |
686 | |
840 | |
687 | On win32, there is no notion of fork so all this doesn't apply, of |
841 | On win32, there is no notion of fork so all this doesn't apply, of |
688 | course. |
842 | course. |
689 | |
843 | |
690 | SEE ALSO |
844 | SEE ALSO |
691 | EV::ADNS (asynchronous dns), Glib::EV (makes Glib/Gtk2 use EV as event |
845 | EV::ADNS (asynchronous DNS), Glib::EV (makes Glib/Gtk2 use EV as event |
692 | loop), Coro::EV (efficient coroutines with EV). |
846 | loop), EV::Glib (embed Glib into EV), Coro::EV (efficient coroutines |
|
|
847 | with EV), Net::SNMP::EV (asynchronous SNMP), AnyEvent for event-loop |
|
|
848 | agnostic and portable event driven programming. |
693 | |
849 | |
694 | AUTHOR |
850 | AUTHOR |
695 | Marc Lehmann <schmorp@schmorp.de> |
851 | Marc Lehmann <schmorp@schmorp.de> |
696 | http://home.schmorp.de/ |
852 | http://home.schmorp.de/ |
697 | |
853 | |