… | |
… | |
37 | # CHILD/PID STATUS CHANGES |
37 | # CHILD/PID STATUS CHANGES |
38 | |
38 | |
39 | my $w = EV::child 666, sub { |
39 | my $w = EV::child 666, sub { |
40 | my ($w, $revents) = @_; |
40 | my ($w, $revents) = @_; |
41 | my $status = $w->rstatus; |
41 | my $status = $w->rstatus; |
|
|
42 | }; |
|
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43 | |
|
|
44 | # STAT CHANGES |
|
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45 | my $w = EV::stat "/etc/passwd", 10, sub { |
|
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46 | my ($w, $revents) = @_; |
|
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47 | warn $w->path, " has changed somehow.\n"; |
42 | }; |
48 | }; |
43 | |
49 | |
44 | # MAINLOOP |
50 | # MAINLOOP |
45 | 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 |
46 | 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 |
… | |
… | |
50 | This module provides an interface to libev |
56 | This module provides an interface to libev |
51 | (<http://software.schmorp.de/pkg/libev.html>). While the documentation |
57 | (<http://software.schmorp.de/pkg/libev.html>). While the documentation |
52 | below is comprehensive, one might also consult the documentation of |
58 | below is comprehensive, one might also consult the documentation of |
53 | libev itself (<http://cvs.schmorp.de/libev/ev.html>) for more subtle |
59 | libev itself (<http://cvs.schmorp.de/libev/ev.html>) for more subtle |
54 | details on watcher semantics or some discussion on the available |
60 | details on watcher semantics or some discussion on the available |
55 | backends, or how to force a specific backend with "LIBEV_FLAGS". |
61 | backends, or how to force a specific backend with "LIBEV_FLAGS", or just |
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62 | about in any case because it has much more detailed information. |
|
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63 | |
|
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64 | EVENT LOOPS |
|
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65 | EV supports multiple event loops: There is a single "default event loop" |
|
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66 | that can handle everything including signals and child watchers, and any |
|
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67 | number of "dynamic event loops" that can use different backends (with |
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68 | various limitations), but no child and signal watchers. |
|
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69 | |
|
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70 | You do not have to do anything to create the default event loop: When |
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71 | the module is loaded a suitable backend is selected on the premise of |
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72 | selecting a working backend (which for example rules out kqueue on most |
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73 | BSDs). Modules should, unless they have "special needs" always use the |
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74 | default loop as this is fastest (perl-wise), best supported by other |
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75 | modules (e.g. AnyEvent or Coro) and most portable event loop. |
|
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76 | |
|
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77 | For specific programs you can create additional event loops dynamically. |
|
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78 | |
|
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79 | $loop = new EV::loop [$flags] |
|
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80 | Create a new event loop as per the specified flags. Please refer to |
|
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81 | the "ev_loop_new ()" function description in the libev documentation |
|
|
82 | (<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#GLOBAL_FUNCTI |
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83 | ONS>) for more info. |
|
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84 | |
|
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85 | The loop will automatically be destroyed when it is no longer |
|
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86 | referenced by any watcher and the loop object goes out of scope. |
|
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87 | |
|
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88 | Using "EV::FLAG_FORKCHECK" is recommended, as only the default event |
|
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89 | loop is protected by this module. |
|
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90 | |
|
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91 | $loop->loop_fork |
|
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92 | Must be called after a fork in the child, before entering or |
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93 | continuing the event loop. An alternative is to use |
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94 | "EV::FLAG_FORKCHECK" which calls this fucntion automatically, at |
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95 | some performance loss (refer to the libev documentation). |
|
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96 | |
|
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97 | $loop = EV::default_loop [$flags] |
|
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98 | Return the default loop (which is a singleton object). |
56 | |
99 | |
57 | BASIC INTERFACE |
100 | BASIC INTERFACE |
58 | $EV::DIED |
101 | $EV::DIED |
59 | Must contain a reference to a function that is called when a |
102 | Must contain a reference to a function that is called when a |
60 | callback throws an exception (with $@ containing thr error). The |
103 | callback throws an exception (with $@ containing the error). The |
61 | default prints an informative message and continues. |
104 | default prints an informative message and continues. |
62 | |
105 | |
63 | If this callback throws an exception it will be silently ignored. |
106 | If this callback throws an exception it will be silently ignored. |
|
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107 | |
|
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108 | $flags = EV::supported_backends |
|
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109 | $flags = EV::recommended_backends |
|
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110 | $flags = EV::embeddable_backends |
|
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111 | Returns the set (see "EV::BACKEND_*" flags) of backends supported by |
|
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112 | this instance of EV, the set of recommended backends (supposed to be |
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113 | good) for this platform and the set of embeddable backends (see |
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114 | EMBED WATCHERS). |
|
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115 | |
|
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116 | EV::sleep $seconds |
|
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117 | Block the process for the given number of (fractional) seconds. |
64 | |
118 | |
65 | $time = EV::time |
119 | $time = EV::time |
66 | Returns the current time in (fractional) seconds since the epoch. |
120 | Returns the current time in (fractional) seconds since the epoch. |
67 | |
121 | |
68 | $time = EV::now |
122 | $time = EV::now |
|
|
123 | $time = $loop->now |
69 | Returns the time the last event loop iteration has been started. |
124 | Returns the time the last event loop iteration has been started. |
70 | This is the time that (relative) timers are based on, and refering |
125 | This is the time that (relative) timers are based on, and refering |
71 | to it is usually faster then calling EV::time. |
126 | to it is usually faster then calling EV::time. |
72 | |
127 | |
73 | $method = EV::method |
128 | $backend = EV::backend |
|
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129 | $backend = $loop->backend |
74 | Returns an integer describing the backend used by libev |
130 | Returns an integer describing the backend used by libev |
75 | (EV::METHOD_SELECT or EV::METHOD_EPOLL). |
131 | (EV::METHOD_SELECT or EV::METHOD_EPOLL). |
76 | |
132 | |
77 | EV::loop [$flags] |
133 | EV::loop [$flags] |
|
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134 | $loop->loop ([$flags]) |
78 | Begin checking for events and calling callbacks. It returns when a |
135 | Begin checking for events and calling callbacks. It returns when a |
79 | callback calls EV::unloop. |
136 | callback calls EV::unloop. |
80 | |
137 | |
81 | The $flags argument can be one of the following: |
138 | The $flags argument can be one of the following: |
82 | |
139 | |
83 | 0 as above |
140 | 0 as above |
84 | EV::LOOP_ONESHOT block at most once (wait, but do not loop) |
141 | EV::LOOP_ONESHOT block at most once (wait, but do not loop) |
85 | EV::LOOP_NONBLOCK do not block at all (fetch/handle events but do not wait) |
142 | EV::LOOP_NONBLOCK do not block at all (fetch/handle events but do not wait) |
86 | |
143 | |
87 | EV::unloop [$how] |
144 | EV::unloop [$how] |
|
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145 | $loop->unloop ([$how]) |
88 | When called with no arguments or an argument of EV::UNLOOP_ONE, |
146 | When called with no arguments or an argument of EV::UNLOOP_ONE, |
89 | makes the innermost call to EV::loop return. |
147 | makes the innermost call to EV::loop return. |
90 | |
148 | |
91 | When called with an argument of EV::UNLOOP_ALL, all calls to |
149 | When called with an argument of EV::UNLOOP_ALL, all calls to |
92 | EV::loop will return as fast as possible. |
150 | EV::loop will return as fast as possible. |
93 | |
151 | |
|
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152 | $count = EV::loop_count |
|
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153 | $count = $loop->loop_count |
|
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154 | Return the number of times the event loop has polled for new events. |
|
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155 | Sometiems useful as a generation counter. |
|
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156 | |
94 | EV::once $fh_or_undef, $events, $timeout, $cb->($revents) |
157 | EV::once $fh_or_undef, $events, $timeout, $cb->($revents) |
|
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158 | $loop->once ($fh_or_undef, $events, $timeout, $cb->($revents)) |
95 | This function rolls together an I/O and a timer watcher for a single |
159 | This function rolls together an I/O and a timer watcher for a single |
96 | one-shot event without the need for managing a watcher object. |
160 | one-shot event without the need for managing a watcher object. |
97 | |
161 | |
98 | If $fh_or_undef is a filehandle or file descriptor, then $events |
162 | If $fh_or_undef is a filehandle or file descriptor, then $events |
99 | must be a bitset containing either "EV::READ", "EV::WRITE" or |
163 | must be a bitset containing either "EV::READ", "EV::WRITE" or |
… | |
… | |
104 | If timeout is "undef" or negative, then there will be no timeout. |
168 | If timeout is "undef" or negative, then there will be no timeout. |
105 | Otherwise a EV::timer with this value will be started. |
169 | Otherwise a EV::timer with this value will be started. |
106 | |
170 | |
107 | When an error occurs or either the timeout or I/O watcher triggers, |
171 | When an error occurs or either the timeout or I/O watcher triggers, |
108 | then the callback will be called with the received event set (in |
172 | then the callback will be called with the received event set (in |
109 | general you can expect it to be a combination of "EV:ERROR", |
173 | general you can expect it to be a combination of "EV::ERROR", |
110 | "EV::READ", "EV::WRITE" and "EV::TIMEOUT"). |
174 | "EV::READ", "EV::WRITE" and "EV::TIMEOUT"). |
111 | |
175 | |
112 | EV::once doesn't return anything: the watchers stay active till |
176 | EV::once doesn't return anything: the watchers stay active till |
113 | either of them triggers, then they will be stopped and freed, and |
177 | either of them triggers, then they will be stopped and freed, and |
114 | the callback invoked. |
178 | the callback invoked. |
115 | |
179 | |
116 | WATCHER |
180 | EV::feed_fd_event ($fd, $revents) |
|
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181 | $loop->feed_fd_event ($fd, $revents) |
|
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182 | Feed an event on a file descriptor into EV. EV will react to this |
|
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183 | call as if the readyness notifications specified by $revents (a |
|
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184 | combination of "EV::READ" and "EV::WRITE") happened on the file |
|
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185 | descriptor $fd. |
|
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186 | |
|
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187 | EV::feed_signal_event ($signal) |
|
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188 | Feed a signal event into EV. EV will react to this call as if the |
|
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189 | signal specified by $signal had occured. |
|
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190 | |
|
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191 | EV::set_io_collect_interval $time |
|
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192 | $loop->set_io_collect_interval ($time) |
|
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193 | EV::set_timeout_collect_interval $time |
|
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194 | $loop->set_timeout_collect_interval ($time) |
|
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195 | These advanced functions set the minimum block interval when polling |
|
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196 | for I/O events and the minimum wait interval for timer events. See |
|
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197 | the libev documentation at |
|
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198 | <http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#FUNCTIONS_CONT |
|
|
199 | ROLLING_THE_EVENT_LOOP> for a more detailed discussion. |
|
|
200 | |
|
|
201 | WATCHER OBJECTS |
117 | A watcher is an object that gets created to record your interest in some |
202 | A watcher is an object that gets created to record your interest in some |
118 | event. For instance, if you want to wait for STDIN to become readable, |
203 | event. For instance, if you want to wait for STDIN to become readable, |
119 | you would create an EV::io watcher for that: |
204 | you would create an EV::io watcher for that: |
120 | |
205 | |
121 | my $watcher = EV::io *STDIN, EV::READ, sub { |
206 | my $watcher = EV::io *STDIN, EV::READ, sub { |
122 | my ($watcher, $revents) = @_; |
207 | my ($watcher, $revents) = @_; |
123 | warn "yeah, STDIN should not be readable without blocking!\n" |
208 | warn "yeah, STDIN should now be readable without blocking!\n" |
124 | }; |
209 | }; |
125 | |
210 | |
126 | All watchers can be active (waiting for events) or inactive (paused). |
211 | All watchers can be active (waiting for events) or inactive (paused). |
127 | Only active watchers will have their callbacks invoked. All callbacks |
212 | Only active watchers will have their callbacks invoked. All callbacks |
128 | will be called with at least two arguments: the watcher and a bitmask of |
213 | will be called with at least two arguments: the watcher and a bitmask of |
129 | received events. |
214 | received events. |
130 | |
215 | |
131 | Each watcher type has its associated bit in revents, so you can use the |
216 | Each watcher type has its associated bit in revents, so you can use the |
132 | same callback for multiple watchers. The event mask is named after the |
217 | same callback for multiple watchers. The event mask is named after the |
133 | type, i..e. EV::child sets EV::CHILD, EV::prepare sets EV::PREPARE, |
218 | type, i..e. EV::child sets EV::CHILD, EV::prepare sets EV::PREPARE, |
134 | EV::periodic sets EV::PERIODIC and so on, with the exception of IO |
219 | EV::periodic sets EV::PERIODIC and so on, with the exception of I/O |
135 | events (which can set both EV::READ and EV::WRITE bits), and EV::timer |
220 | events (which can set both EV::READ and EV::WRITE bits), and EV::timer |
136 | (which uses EV::TIMEOUT). |
221 | (which uses EV::TIMEOUT). |
137 | |
222 | |
138 | In the rare case where one wants to create a watcher but not start it at |
223 | In the rare case where one wants to create a watcher but not start it at |
139 | the same time, each constructor has a variant with a trailing "_ns" in |
224 | the same time, each constructor has a variant with a trailing "_ns" in |
… | |
… | |
145 | |
230 | |
146 | Also, all methods changing some aspect of a watcher (->set, ->priority, |
231 | Also, all methods changing some aspect of a watcher (->set, ->priority, |
147 | ->fh and so on) automatically stop and start it again if it is active, |
232 | ->fh and so on) automatically stop and start it again if it is active, |
148 | which means pending events get lost. |
233 | which means pending events get lost. |
149 | |
234 | |
150 | WATCHER TYPES |
235 | COMMON WATCHER METHODS |
151 | Now lets move to the existing watcher types and asociated methods. |
236 | This section lists methods common to all watchers. |
152 | |
|
|
153 | The following methods are available for all watchers. Then followes a |
|
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154 | description of each watcher constructor (EV::io, EV::timer, |
|
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155 | EV::periodic, EV::signal, EV::child, EV::idle, EV::prepare and |
|
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156 | EV::check), followed by any type-specific methods (if any). |
|
|
157 | |
237 | |
158 | $w->start |
238 | $w->start |
159 | Starts a watcher if it isn't active already. Does nothing to an |
239 | Starts a watcher if it isn't active already. Does nothing to an |
160 | already active watcher. By default, all watchers start out in the |
240 | already active watcher. By default, all watchers start out in the |
161 | active state (see the description of the "_ns" variants if you need |
241 | active state (see the description of the "_ns" variants if you need |
162 | stopped watchers). |
242 | stopped watchers). |
163 | |
243 | |
164 | $w->stop |
244 | $w->stop |
165 | Stop a watcher if it is active. Also clear any pending events |
245 | Stop a watcher if it is active. Also clear any pending events |
166 | (events that have been received but that didn't yet result in a |
246 | (events that have been received but that didn't yet result in a |
167 | callback invocation), regardless of wether the watcher was active or |
247 | callback invocation), regardless of whether the watcher was active |
168 | not. |
248 | or not. |
169 | |
249 | |
170 | $bool = $w->is_active |
250 | $bool = $w->is_active |
171 | Returns true if the watcher is active, false otherwise. |
251 | Returns true if the watcher is active, false otherwise. |
172 | |
252 | |
173 | $current_data = $w->data |
253 | $current_data = $w->data |
… | |
… | |
196 | The default priority of any newly-created watcher is 0. |
276 | The default priority of any newly-created watcher is 0. |
197 | |
277 | |
198 | Note that the priority semantics have not yet been fleshed out and |
278 | Note that the priority semantics have not yet been fleshed out and |
199 | are subject to almost certain change. |
279 | are subject to almost certain change. |
200 | |
280 | |
201 | $w->trigger ($revents) |
281 | $w->invoke ($revents) |
202 | Call the callback *now* with the given event mask. |
282 | Call the callback *now* with the given event mask. |
|
|
283 | |
|
|
284 | $w->feed_event ($revents) |
|
|
285 | Feed some events on this watcher into EV. EV will react to this call |
|
|
286 | as if the watcher had received the given $revents mask. |
|
|
287 | |
|
|
288 | $revents = $w->clear_pending |
|
|
289 | If the watcher is pending, this function clears its pending status |
|
|
290 | and returns its $revents bitset (as if its callback was invoked). If |
|
|
291 | the watcher isn't pending it does nothing and returns 0. |
203 | |
292 | |
204 | $previous_state = $w->keepalive ($bool) |
293 | $previous_state = $w->keepalive ($bool) |
205 | Normally, "EV::loop" will return when there are no active watchers |
294 | Normally, "EV::loop" will return when there are no active watchers |
206 | (which is a "deadlock" because no progress can be made anymore). |
295 | (which is a "deadlock" because no progress can be made anymore). |
207 | This is convinient because it allows you to start your watchers (and |
296 | This is convinient because it allows you to start your watchers (and |
208 | your jobs), call "EV::loop" once and when it returns you know that |
297 | your jobs), call "EV::loop" once and when it returns you know that |
209 | all your jobs are finished (or they forgot to register some watchers |
298 | all your jobs are finished (or they forgot to register some watchers |
210 | for their task :). |
299 | for their task :). |
211 | |
300 | |
212 | Sometimes, however, this gets in your way, for example when you the |
301 | Sometimes, however, this gets in your way, for example when the |
213 | module that calls "EV::loop" (usually the main program) is not the |
302 | module that calls "EV::loop" (usually the main program) is not the |
214 | same module as a long-living watcher (for example a DNS client |
303 | same module as a long-living watcher (for example a DNS client |
215 | module written by somebody else even). Then you might want any |
304 | module written by somebody else even). Then you might want any |
216 | outstanding requests to be handled, but you would not want to keep |
305 | outstanding requests to be handled, but you would not want to keep |
217 | "EV::loop" from returning just because you happen to have this |
306 | "EV::loop" from returning just because you happen to have this |
… | |
… | |
222 | returning. |
311 | returning. |
223 | |
312 | |
224 | The initial value for keepalive is true (enabled), and you cna |
313 | The initial value for keepalive is true (enabled), and you cna |
225 | change it any time. |
314 | change it any time. |
226 | |
315 | |
227 | Example: Register an IO watcher for some UDP socket but do not keep |
316 | Example: Register an I/O watcher for some UDP socket but do not keep |
228 | the event loop from running just because of that watcher. |
317 | the event loop from running just because of that watcher. |
229 | |
318 | |
230 | my $udp_socket = ... |
319 | my $udp_socket = ... |
231 | my $udp_watcher = EV::io $udp_socket, EV::READ, sub { ... }; |
320 | my $udp_watcher = EV::io $udp_socket, EV::READ, sub { ... }; |
232 | $udp_watcher->keepalive (0); |
321 | $1000udp_watcher->keepalive (0); |
233 | |
322 | |
|
|
323 | $loop = $w->loop |
|
|
324 | Return the loop that this watcher is attached to. |
|
|
325 | |
|
|
326 | WATCHER TYPES |
|
|
327 | Each of the following subsections describes a single watcher type. |
|
|
328 | |
|
|
329 | I/O WATCHERS - is this file descriptor readable or writable? |
234 | $w = EV::io $fileno_or_fh, $eventmask, $callback |
330 | $w = EV::io $fileno_or_fh, $eventmask, $callback |
235 | $w = EV::io_ns $fileno_or_fh, $eventmask, $callback |
331 | $w = EV::io_ns $fileno_or_fh, $eventmask, $callback |
|
|
332 | $w = $loop->io ($fileno_or_fh, $eventmask, $callback) |
|
|
333 | $w = $loop->io_ns ($fileno_or_fh, $eventmask, $callback) |
236 | As long as the returned watcher object is alive, call the $callback |
334 | As long as the returned watcher object is alive, call the $callback |
237 | when the events specified in $eventmask. |
335 | when at least one of events specified in $eventmask occurs. |
238 | |
336 | |
239 | The $eventmask can be one or more of these constants ORed together: |
337 | The $eventmask can be one or more of these constants ORed together: |
240 | |
338 | |
241 | EV::READ wait until read() wouldn't block anymore |
339 | EV::READ wait until read() wouldn't block anymore |
242 | EV::WRITE wait until write() wouldn't block anymore |
340 | EV::WRITE wait until write() wouldn't block anymore |
… | |
… | |
254 | |
352 | |
255 | $current_eventmask = $w->events |
353 | $current_eventmask = $w->events |
256 | $old_eventmask = $w->events ($new_eventmask) |
354 | $old_eventmask = $w->events ($new_eventmask) |
257 | Returns the previously set event mask and optionally set a new one. |
355 | Returns the previously set event mask and optionally set a new one. |
258 | |
356 | |
|
|
357 | TIMER WATCHERS - relative and optionally repeating timeouts |
259 | $w = EV::timer $after, $repeat, $callback |
358 | $w = EV::timer $after, $repeat, $callback |
260 | $w = EV::timer_ns $after, $repeat, $callback |
359 | $w = EV::timer_ns $after, $repeat, $callback |
|
|
360 | $w = $loop->timer ($after, $repeat, $callback) |
|
|
361 | $w = $loop->timer_ns ($after, $repeat, $callback) |
261 | Calls the callback after $after seconds (which may be fractional). |
362 | Calls the callback after $after seconds (which may be fractional). |
262 | If $repeat is non-zero, the timer will be restarted (with the |
363 | If $repeat is non-zero, the timer will be restarted (with the |
263 | $repeat value as $after) after the callback returns. |
364 | $repeat value as $after) after the callback returns. |
264 | |
365 | |
265 | This means that the callback would be called roughly after $after |
366 | This means that the callback would be called roughly after $after |
… | |
… | |
277 | The "timer_ns" variant doesn't start (activate) the newly created |
378 | The "timer_ns" variant doesn't start (activate) the newly created |
278 | watcher. |
379 | watcher. |
279 | |
380 | |
280 | $w->set ($after, $repeat) |
381 | $w->set ($after, $repeat) |
281 | Reconfigures the watcher, see the constructor above for details. Can |
382 | Reconfigures the watcher, see the constructor above for details. Can |
282 | be at any time. |
383 | be called at any time. |
283 | |
384 | |
284 | $w->again |
385 | $w->again |
285 | Similar to the "start" method, but has special semantics for |
386 | Similar to the "start" method, but has special semantics for |
286 | repeating timers: |
387 | repeating timers: |
287 | |
388 | |
… | |
… | |
298 | This behaviour is useful when you have a timeout for some IO |
399 | This behaviour is useful when you have a timeout for some IO |
299 | operation. You create a timer object with the same value for $after |
400 | operation. You create a timer object with the same value for $after |
300 | and $repeat, and then, in the read/write watcher, run the "again" |
401 | and $repeat, and then, in the read/write watcher, run the "again" |
301 | method on the timeout. |
402 | method on the timeout. |
302 | |
403 | |
|
|
404 | PERIODIC WATCHERS - to cron or not to cron? |
303 | $w = EV::periodic $at, $interval, $reschedule_cb, $callback |
405 | $w = EV::periodic $at, $interval, $reschedule_cb, $callback |
304 | $w = EV::periodic_ns $at, $interval, $reschedule_cb, $callback |
406 | $w = EV::periodic_ns $at, $interval, $reschedule_cb, $callback |
|
|
407 | $w = $loop->periodic ($at, $interval, $reschedule_cb, $callback) |
|
|
408 | $w = $loop->periodic_ns ($at, $interval, $reschedule_cb, $callback) |
305 | Similar to EV::timer, but is not based on relative timeouts but on |
409 | Similar to EV::timer, but is not based on relative timeouts but on |
306 | absolute times. Apart from creating "simple" timers that trigger |
410 | absolute times. Apart from creating "simple" timers that trigger |
307 | "at" the specified time, it can also be used for non-drifting |
411 | "at" the specified time, it can also be used for non-drifting |
308 | absolute timers and more complex, cron-like, setups that are not |
412 | absolute timers and more complex, cron-like, setups that are not |
309 | adversely affected by time jumps (i.e. when the system clock is |
413 | adversely affected by time jumps (i.e. when the system clock is |
… | |
… | |
372 | The "periodic_ns" variant doesn't start (activate) the newly created |
476 | The "periodic_ns" variant doesn't start (activate) the newly created |
373 | watcher. |
477 | watcher. |
374 | |
478 | |
375 | $w->set ($at, $interval, $reschedule_cb) |
479 | $w->set ($at, $interval, $reschedule_cb) |
376 | Reconfigures the watcher, see the constructor above for details. Can |
480 | Reconfigures the watcher, see the constructor above for details. Can |
377 | be at any time. |
481 | be called at any time. |
378 | |
482 | |
379 | $w->again |
483 | $w->again |
380 | Simply stops and starts the watcher again. |
484 | Simply stops and starts the watcher again. |
381 | |
485 | |
|
|
486 | $time = $w->at |
|
|
487 | Return the time that the watcher is expected to trigger next. |
|
|
488 | |
|
|
489 | SIGNAL WATCHERS - signal me when a signal gets signalled! |
382 | $w = EV::signal $signal, $callback |
490 | $w = EV::signal $signal, $callback |
383 | $w = EV::signal_ns $signal, $callback |
491 | $w = EV::signal_ns $signal, $callback |
384 | Call the callback when $signal is received (the signal can be |
492 | Call the callback when $signal is received (the signal can be |
385 | specified by number or by name, just as with kill or %SIG). |
493 | specified by number or by name, just as with "kill" or %SIG). |
386 | |
494 | |
387 | EV will grab the signal for the process (the kernel only allows one |
495 | EV will grab the signal for the process (the kernel only allows one |
388 | component to receive a signal at a time) when you start a signal |
496 | component to receive a signal at a time) when you start a signal |
389 | watcher, and removes it again when you stop it. Perl does the same |
497 | watcher, and removes it again when you stop it. Perl does the same |
390 | when you add/remove callbacks to %SIG, so watch out. |
498 | when you add/remove callbacks to %SIG, so watch out. |
… | |
… | |
394 | The "signal_ns" variant doesn't start (activate) the newly created |
502 | The "signal_ns" variant doesn't start (activate) the newly created |
395 | watcher. |
503 | watcher. |
396 | |
504 | |
397 | $w->set ($signal) |
505 | $w->set ($signal) |
398 | Reconfigures the watcher, see the constructor above for details. Can |
506 | Reconfigures the watcher, see the constructor above for details. Can |
399 | be at any time. |
507 | be called at any time. |
400 | |
508 | |
401 | $current_signum = $w->signal |
509 | $current_signum = $w->signal |
402 | $old_signum = $w->signal ($new_signal) |
510 | $old_signum = $w->signal ($new_signal) |
403 | Returns the previously set signal (always as a number not name) and |
511 | Returns the previously set signal (always as a number not name) and |
404 | optionally set a new one. |
512 | optionally set a new one. |
405 | |
513 | |
|
|
514 | CHILD WATCHERS - watch out for process status changes |
406 | $w = EV::child $pid, $callback |
515 | $w = EV::child $pid, $callback |
407 | $w = EV::child_ns $pid, $callback |
516 | $w = EV::child_ns $pid, $callback |
|
|
517 | $w = $loop->child ($pid, $callback) |
|
|
518 | $w = $loop->child_ns ($pid, $callback) |
408 | Call the callback when a status change for pid $pid (or any pid if |
519 | Call the callback when a status change for pid $pid (or any pid if |
409 | $pid is 0) has been received. More precisely: when the process |
520 | $pid is 0) has been received. More precisely: when the process |
410 | receives a SIGCHLD, EV will fetch the outstanding exit/wait status |
521 | receives a "SIGCHLD", EV will fetch the outstanding exit/wait status |
411 | for all changed/zombie children and call the callback. |
522 | for all changed/zombie children and call the callback. |
412 | |
523 | |
413 | You can access both status and pid by using the "rstatus" and "rpid" |
524 | It is valid (and fully supported) to install a child watcher after a |
|
|
525 | child has exited but before the event loop has started its next |
|
|
526 | iteration (for example, first you "fork", then the new child process |
|
|
527 | might exit, and only then do you install a child watcher in the |
|
|
528 | parent for the new pid). |
|
|
529 | |
|
|
530 | You can access both exit (or tracing) status and pid by using the |
414 | methods on the watcher object. |
531 | "rstatus" and "rpid" methods on the watcher object. |
415 | |
532 | |
416 | You can have as many pid watchers per pid as you want. |
533 | You can have as many pid watchers per pid as you want, they will all |
|
|
534 | be called. |
417 | |
535 | |
418 | The "child_ns" variant doesn't start (activate) the newly created |
536 | The "child_ns" variant doesn't start (activate) the newly created |
419 | watcher. |
537 | watcher. |
420 | |
538 | |
421 | $w->set ($pid) |
539 | $w->set ($pid) |
422 | Reconfigures the watcher, see the constructor above for details. Can |
540 | Reconfigures the watcher, see the constructor above for details. Can |
423 | be at any time. |
541 | be called at any time. |
424 | |
542 | |
425 | $current_pid = $w->pid |
543 | $current_pid = $w->pid |
426 | $old_pid = $w->pid ($new_pid) |
544 | $old_pid = $w->pid ($new_pid) |
427 | Returns the previously set process id and optionally set a new one. |
545 | Returns the previously set process id and optionally set a new one. |
428 | |
546 | |
… | |
… | |
432 | |
550 | |
433 | $pid = $w->rpid |
551 | $pid = $w->rpid |
434 | Return the pid of the awaited child (useful when you have installed |
552 | Return the pid of the awaited child (useful when you have installed |
435 | a watcher for all pids). |
553 | a watcher for all pids). |
436 | |
554 | |
|
|
555 | STAT WATCHERS - did the file attributes just change? |
|
|
556 | $w = EV::stat $path, $interval, $callback |
|
|
557 | $w = EV::stat_ns $path, $interval, $callback |
|
|
558 | $w = $loop->stat ($path, $interval, $callback) |
|
|
559 | $w = $loop->stat_ns ($path, $interval, $callback) |
|
|
560 | Call the callback when a file status change has been detected on |
|
|
561 | $path. The $path does not need to exist, changing from "path exists" |
|
|
562 | to "path does not exist" is a status change like any other. |
|
|
563 | |
|
|
564 | The $interval is a recommended polling interval for systems where |
|
|
565 | OS-supported change notifications don't exist or are not supported. |
|
|
566 | If you use 0 then an unspecified default is used (which is highly |
|
|
567 | recommended!), which is to be expected to be around five seconds |
|
|
568 | usually. |
|
|
569 | |
|
|
570 | This watcher type is not meant for massive numbers of stat watchers, |
|
|
571 | as even with OS-supported change notifications, this can be |
|
|
572 | resource-intensive. |
|
|
573 | |
|
|
574 | The "stat_ns" variant doesn't start (activate) the newly created |
|
|
575 | watcher. |
|
|
576 | |
|
|
577 | ... = $w->stat |
|
|
578 | This call is very similar to the perl "stat" built-in: It stats |
|
|
579 | (using "lstat") the path specified in the watcher and sets perls |
|
|
580 | stat cache (as well as EV's idea of the current stat values) to the |
|
|
581 | values found. |
|
|
582 | |
|
|
583 | In scalar context, a boolean is return indicating success or failure |
|
|
584 | of the stat. In list context, the same 13-value list as with stat is |
|
|
585 | returned (except that the blksize and blocks fields are not |
|
|
586 | reliable). |
|
|
587 | |
|
|
588 | In the case of an error, errno is set to "ENOENT" (regardless of the |
|
|
589 | actual error value) and the "nlink" value is forced to zero (if the |
|
|
590 | stat was successful then nlink is guaranteed to be non-zero). |
|
|
591 | |
|
|
592 | See also the next two entries for more info. |
|
|
593 | |
|
|
594 | ... = $w->attr |
|
|
595 | Just like "$w->stat", but without the initial stat'ing: this returns |
|
|
596 | the values most recently detected by EV. See the next entry for more |
|
|
597 | info. |
|
|
598 | |
|
|
599 | ... = $w->prev |
|
|
600 | Just like "$w->stat", but without the initial stat'ing: this returns |
|
|
601 | the previous set of values, before the change. |
|
|
602 | |
|
|
603 | That is, when the watcher callback is invoked, "$w->prev" will be |
|
|
604 | set to the values found *before* a change was detected, while |
|
|
605 | "$w->attr" returns the values found leading to the change detection. |
|
|
606 | The difference (if any) between "prev" and "attr" is what triggered |
|
|
607 | the callback. |
|
|
608 | |
|
|
609 | If you did something to the filesystem object and do not want to |
|
|
610 | trigger yet another change, you can call "stat" to update EV's idea |
|
|
611 | of what the current attributes are. |
|
|
612 | |
|
|
613 | $w->set ($path, $interval) |
|
|
614 | Reconfigures the watcher, see the constructor above for details. Can |
|
|
615 | be called at any time. |
|
|
616 | |
|
|
617 | $current_path = $w->path |
|
|
618 | $old_path = $w->path ($new_path) |
|
|
619 | Returns the previously set path and optionally set a new one. |
|
|
620 | |
|
|
621 | $current_interval = $w->interval |
|
|
622 | $old_interval = $w->interval ($new_interval) |
|
|
623 | Returns the previously set interval and optionally set a new one. |
|
|
624 | Can be used to query the actual interval used. |
|
|
625 | |
|
|
626 | IDLE WATCHERS - when you've got nothing better to do... |
437 | $w = EV::idle $callback |
627 | $w = EV::idle $callback |
438 | $w = EV::idle_ns $callback |
628 | $w = EV::idle_ns $callback |
|
|
629 | $w = $loop->idle ($callback) |
|
|
630 | $w = $loop->idle_ns ($callback) |
439 | Call the callback when there are no pending io, timer/periodic, |
631 | Call the callback when there are no other pending watchers of the |
440 | signal or child events, i.e. when the process is idle. |
632 | same or higher priority (excluding check, prepare and other idle |
|
|
633 | watchers of the same or lower priority, of course). They are called |
|
|
634 | idle watchers because when the watcher is the highest priority |
|
|
635 | pending event in the process, the process is considered to be idle |
|
|
636 | at that priority. |
|
|
637 | |
|
|
638 | If you want a watcher that is only ever called when *no* other |
|
|
639 | events are outstanding you have to set the priority to "EV::MINPRI". |
441 | |
640 | |
442 | The process will not block as long as any idle watchers are active, |
641 | The process will not block as long as any idle watchers are active, |
443 | and they will be called repeatedly until stopped. |
642 | and they will be called repeatedly until stopped. |
444 | |
643 | |
|
|
644 | For example, if you have idle watchers at priority 0 and 1, and an |
|
|
645 | I/O watcher at priority 0, then the idle watcher at priority 1 and |
|
|
646 | the I/O watcher will always run when ready. Only when the idle |
|
|
647 | watcher at priority 1 is stopped and the I/O watcher at priority 0 |
|
|
648 | is not pending with the 0-priority idle watcher be invoked. |
|
|
649 | |
445 | The "idle_ns" variant doesn't start (activate) the newly created |
650 | The "idle_ns" variant doesn't start (activate) the newly created |
446 | watcher. |
651 | watcher. |
447 | |
652 | |
|
|
653 | PREPARE WATCHERS - customise your event loop! |
448 | $w = EV::prepare $callback |
654 | $w = EV::prepare $callback |
449 | $w = EV::prepare_ns $callback |
655 | $w = EV::prepare_ns $callback |
|
|
656 | $w = $loop->prepare ($callback) |
|
|
657 | $w = $loop->prepare_ns ($callback) |
450 | Call the callback just before the process would block. You can still |
658 | Call the callback just before the process would block. You can still |
451 | create/modify any watchers at this point. |
659 | create/modify any watchers at this point. |
452 | |
660 | |
453 | See the EV::check watcher, below, for explanations and an example. |
661 | See the EV::check watcher, below, for explanations and an example. |
454 | |
662 | |
455 | The "prepare_ns" variant doesn't start (activate) the newly created |
663 | The "prepare_ns" variant doesn't start (activate) the newly created |
456 | watcher. |
664 | watcher. |
457 | |
665 | |
|
|
666 | CHECK WATCHERS - customise your event loop even more! |
458 | $w = EV::check $callback |
667 | $w = EV::check $callback |
459 | $w = EV::check_ns $callback |
668 | $w = EV::check_ns $callback |
|
|
669 | $w = $loop->check ($callback) |
|
|
670 | $w = $loop->check_ns ($callback) |
460 | Call the callback just after the process wakes up again (after it |
671 | Call the callback just after the process wakes up again (after it |
461 | has gathered events), but before any other callbacks have been |
672 | has gathered events), but before any other callbacks have been |
462 | invoked. |
673 | invoked. |
463 | |
674 | |
464 | This is used to integrate other event-based software into the EV |
675 | This is used to integrate other event-based software into the EV |
… | |
… | |
475 | or return; |
686 | or return; |
476 | |
687 | |
477 | # make the dispatcher handle any outstanding stuff |
688 | # make the dispatcher handle any outstanding stuff |
478 | ... not shown |
689 | ... not shown |
479 | |
690 | |
480 | # create an IO watcher for each and every socket |
691 | # create an I/O watcher for each and every socket |
481 | @snmp_watcher = ( |
692 | @snmp_watcher = ( |
482 | (map { EV::io $_, EV::READ, sub { } } |
693 | (map { EV::io $_, EV::READ, sub { } } |
483 | keys %{ $dispatcher->{_descriptors} }), |
694 | keys %{ $dispatcher->{_descriptors} }), |
484 | |
695 | |
485 | EV::timer +($event->[Net::SNMP::Dispatcher::_ACTIVE] |
696 | EV::timer +($event->[Net::SNMP::Dispatcher::_ACTIVE] |
… | |
… | |
505 | watchers are destroyed before this cna happen (remember EV::check |
716 | watchers are destroyed before this cna happen (remember EV::check |
506 | gets called first). |
717 | gets called first). |
507 | |
718 | |
508 | The "check_ns" variant doesn't start (activate) the newly created |
719 | The "check_ns" variant doesn't start (activate) the newly created |
509 | watcher. |
720 | watcher. |
|
|
721 | |
|
|
722 | FORK WATCHERS - the audacity to resume the event loop after a fork |
|
|
723 | Fork watchers are called when a "fork ()" was detected. The invocation |
|
|
724 | is done before the event loop blocks next and before "check" watchers |
|
|
725 | are being called, and only in the child after the fork. |
|
|
726 | |
|
|
727 | $w = EV::fork $callback |
|
|
728 | $w = EV::fork_ns $callback |
|
|
729 | $w = $loop->fork ($callback) |
|
|
730 | $w = $loop->fork_ns ($callback) |
|
|
731 | Call the callback before the event loop is resumed in the child |
|
|
732 | process after a fork. |
|
|
733 | |
|
|
734 | The "fork_ns" variant doesn't start (activate) the newly created |
|
|
735 | watcher. |
|
|
736 | |
|
|
737 | EMBED WATCHERS - when one backend isn't enough... |
|
|
738 | This is a rather advanced watcher type that lets you embed one event |
|
|
739 | loop into another (currently only IO events are supported in the |
|
|
740 | embedded loop, other types of watchers might be handled in a delayed or |
|
|
741 | incorrect fashion and must not be used). |
|
|
742 | |
|
|
743 | See the libev documentation at |
|
|
744 | <http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#code_ev_embed_code |
|
|
745 | _when_one_backend_> for more details. |
|
|
746 | |
|
|
747 | In short, this watcher is most useful on BSD systems without working |
|
|
748 | kqueue to still be able to handle a large number of sockets: |
|
|
749 | |
|
|
750 | my $socket_loop; |
|
|
751 | |
|
|
752 | # check wether we use SELECT or POLL _and_ KQUEUE is supported |
|
|
753 | if ( |
|
|
754 | (EV::backend & (EV::BACKEND_POLL | EV::BACKEND_SELECT)) |
|
|
755 | && (EV::supported_backends & EV::embeddable_backends & EV::BACKEND_KQUEUE) |
|
|
756 | ) { |
|
|
757 | # use kqueue for sockets |
|
|
758 | $socket_loop = new EV::Loop EV::BACKEND_KQUEUE | EV::FLAG_NOENV; |
|
|
759 | } |
|
|
760 | |
|
|
761 | # use the default loop otherwise |
|
|
762 | $socket_loop ||= EV::default_loop; |
|
|
763 | |
|
|
764 | $w = EV::embed $otherloop, $callback |
|
|
765 | $w = EV::embed_ns $otherloop, $callback |
|
|
766 | $w = $loop->embed ($otherloop, $callback) |
|
|
767 | $w = $loop->embed_ns ($otherloop, $callback) |
|
|
768 | Call the callback when the embedded event loop ($otherloop) has any |
|
|
769 | I/O activity. The $callback should alwas be specified as "undef" in |
|
|
770 | this version of EV, which means the embedded event loop will be |
|
|
771 | managed automatically. |
|
|
772 | |
|
|
773 | The "embed_ns" variant doesn't start (activate) the newly created |
|
|
774 | watcher. |
|
|
775 | |
|
|
776 | PERL SIGNALS |
|
|
777 | While Perl signal handling (%SIG) is not affected by EV, the behaviour |
|
|
778 | with EV is as the same as any other C library: Perl-signals will only be |
|
|
779 | handled when Perl runs, which means your signal handler might be invoked |
|
|
780 | only the next time an event callback is invoked. |
|
|
781 | |
|
|
782 | The solution is to use EV signal watchers (see "EV::signal"), which will |
|
|
783 | ensure proper operations with regards to other event watchers. |
|
|
784 | |
|
|
785 | If you cannot do this for whatever reason, you can also force a watcher |
|
|
786 | to be called on every event loop iteration by installing a "EV::check" |
|
|
787 | watcher: |
|
|
788 | |
|
|
789 | my $async_check = EV::check sub { }; |
|
|
790 | |
|
|
791 | This ensures that perl gets into control for a short time to handle any |
|
|
792 | pending signals, and also ensures (slightly) slower overall operation. |
510 | |
793 | |
511 | THREADS |
794 | THREADS |
512 | Threads are not supported by this module in any way. Perl pseudo-threads |
795 | Threads are not supported by this module in any way. Perl pseudo-threads |
513 | is evil stuff and must die. As soon as Perl gains real threads I will |
796 | is evil stuff and must die. As soon as Perl gains real threads I will |
514 | work on thread support for it. |
797 | work on thread support for it. |
… | |
… | |
529 | |
812 | |
530 | On win32, there is no notion of fork so all this doesn't apply, of |
813 | On win32, there is no notion of fork so all this doesn't apply, of |
531 | course. |
814 | course. |
532 | |
815 | |
533 | SEE ALSO |
816 | SEE ALSO |
534 | L<EV::DNS>. |
817 | EV::ADNS (asynchronous DNS), Glib::EV (makes Glib/Gtk2 use EV as event |
|
|
818 | loop), EV::Glib (embed Glib into EV), Coro::EV (efficient coroutines |
|
|
819 | with EV), Net::SNMP::EV (asynchronous SNMP). |
535 | |
820 | |
536 | AUTHOR |
821 | AUTHOR |
537 | Marc Lehmann <schmorp@schmorp.de> |
822 | Marc Lehmann <schmorp@schmorp.de> |
538 | http://home.schmorp.de/ |
823 | http://home.schmorp.de/ |
539 | |
824 | |