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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 | }; |
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23 | |
23 | |
24 | # IO |
24 | # IO |
25 | |
25 | |
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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, 0, 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::run; # loop until EV::break is called or all watchers stop |
52 | EV::loop EV::LOOP_ONESHOT; # block until at least one event could be handled |
52 | EV::run EV::RUN_ONCE; # 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::run EV::RUN_NOWAIT; # try to handle same events, but do not block |
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54 | |
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55 | BEFORE YOU START USING THIS MODULE |
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56 | If you only need timer, I/O, signal, child and idle watchers and not the |
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57 | advanced functionality of this module, consider using AnyEvent instead, |
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58 | specifically the simplified API described in AE. |
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59 | |
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60 | When used with EV as backend, the AE API is as fast as the native EV |
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61 | API, but your programs/modules will still run with many other event |
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62 | loops. |
54 | |
63 | |
55 | DESCRIPTION |
64 | DESCRIPTION |
56 | This module provides an interface to libev |
65 | This module provides an interface to libev |
57 | (<http://software.schmorp.de/pkg/libev.html>). While the documentation |
66 | (<http://software.schmorp.de/pkg/libev.html>). While the documentation |
58 | below is comprehensive, one might also consult the documentation of |
67 | below is comprehensive, one might also consult the documentation of |
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66 | can use it through the AnyEvent module, stay portable to other event |
75 | can use it through the AnyEvent module, stay portable to other event |
67 | loops (if you don't rely on any watcher types not available through it) |
76 | loops (if you don't rely on any watcher types not available through it) |
68 | and still be faster than with any other event loop currently supported |
77 | and still be faster than with any other event loop currently supported |
69 | in Perl. |
78 | in Perl. |
70 | |
79 | |
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80 | PORTING FROM EV 3.X to 4.X |
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81 | EV version 4 introduces a number of incompatible changes summarised |
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82 | here. According to the depreciation strategy used by libev, there is a |
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83 | compatibility layer in place so programs should continue to run |
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84 | unchanged (the XS interface lacks this layer, so programs using that one |
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85 | need to be updated). |
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86 | |
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87 | This compatibility layer will be switched off in some future release. |
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88 | |
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89 | All changes relevant to Perl are renames of symbols, functions and |
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90 | methods: |
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91 | |
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92 | EV::loop => EV::run |
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93 | EV::LOOP_NONBLOCK => EV::RUN_NOWAIT |
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94 | EV::LOOP_ONESHOT => EV::RUN_ONCE |
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95 | |
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96 | EV::unloop => EV::break |
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97 | EV::UNLOOP_CANCEL => EV::BREAK_CANCEL |
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98 | EV::UNLOOP_ONE => EV::BREAK_ONE |
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99 | EV::UNLOOP_ALL => EV::BREAK_ALL |
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100 | |
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101 | EV::TIMEOUT => EV::TIMER |
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102 | |
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103 | EV::loop_count => EV::iteration |
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104 | EV::loop_depth => EV::depth |
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105 | EV::loop_verify => EV::verify |
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106 | |
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107 | The loop object methods corresponding to the functions above have been |
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108 | similarly renamed. |
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109 | |
71 | MODULE EXPORTS |
110 | MODULE EXPORTS |
72 | This module does not export any symbols. |
111 | This module does not export any symbols. |
73 | |
112 | |
74 | EVENT LOOPS |
113 | EVENT LOOPS |
75 | EV supports multiple event loops: There is a single "default event loop" |
114 | EV supports multiple event loops: There is a single "default event loop" |
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91 | *embed* a kqueue loop into the default loop: running the default loop |
130 | *embed* a kqueue loop into the default loop: running the default loop |
92 | will then also service the kqueue loop to some extent. See the example |
131 | will then also service the kqueue loop to some extent. See the example |
93 | in the section about embed watchers for an example on how to achieve |
132 | in the section about embed watchers for an example on how to achieve |
94 | that. |
133 | that. |
95 | |
134 | |
96 | $loop = new EV::loop [$flags] |
135 | $loop = new EV::Loop [$flags] |
97 | Create a new event loop as per the specified flags. Please refer to |
136 | Create a new event loop as per the specified flags. Please refer to |
98 | the "ev_loop_new ()" function description in the libev documentation |
137 | the "ev_loop_new ()" function description in the libev documentation |
99 | (<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#GLOBAL_FUNCTI |
138 | (<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#GLOBAL_FUNCTI |
100 | ONS>, or locally-installed as EV::libev manpage) for more info. |
139 | ONS>, or locally-installed as EV::libev manpage) for more info. |
101 | |
140 | |
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112 | Must be called after a fork in the child, before entering or |
151 | Must be called after a fork in the child, before entering or |
113 | continuing the event loop. An alternative is to use |
152 | continuing the event loop. An alternative is to use |
114 | "EV::FLAG_FORKCHECK" which calls this function automatically, at |
153 | "EV::FLAG_FORKCHECK" which calls this function automatically, at |
115 | some performance loss (refer to the libev documentation). |
154 | some performance loss (refer to the libev documentation). |
116 | |
155 | |
117 | $loop->loop_verify |
156 | $loop->verify |
118 | Calls "ev_verify" to make internal consistency checks (for debugging |
157 | Calls "ev_verify" to make internal consistency checks (for debugging |
119 | libev) and abort the program if any data structures were found to be |
158 | libev) and abort the program if any data structures were found to be |
120 | corrupted. |
159 | corrupted. |
121 | |
160 | |
122 | $loop = EV::default_loop [$flags] |
161 | $loop = EV::default_loop [$flags] |
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152 | $time = $loop->now |
191 | $time = $loop->now |
153 | Returns the time the last event loop iteration has been started. |
192 | Returns the time the last event loop iteration has been started. |
154 | This is the time that (relative) timers are based on, and referring |
193 | This is the time that (relative) timers are based on, and referring |
155 | to it is usually faster then calling EV::time. |
194 | to it is usually faster then calling EV::time. |
156 | |
195 | |
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196 | EV::now_update |
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197 | $loop->now_update |
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198 | Establishes the current time by querying the kernel, updating the |
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199 | time returned by "EV::now" in the progress. This is a costly |
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200 | operation and is usually done automatically within "EV::run". |
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201 | |
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202 | This function is rarely useful, but when some event callback runs |
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203 | for a very long time without entering the event loop, updating |
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204 | libev's idea of the current time is a good idea. |
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205 | |
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206 | EV::suspend |
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207 | $loop->suspend |
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208 | EV::resume |
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209 | $loop->resume |
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210 | These two functions suspend and resume a loop, for use when the loop |
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211 | is not used for a while and timeouts should not be processed. |
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212 | |
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213 | A typical use case would be an interactive program such as a game: |
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214 | When the user presses "^Z" to suspend the game and resumes it an |
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215 | hour later it would be best to handle timeouts as if no time had |
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216 | actually passed while the program was suspended. This can be |
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217 | achieved by calling "suspend" in your "SIGTSTP" handler, sending |
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218 | yourself a "SIGSTOP" and calling "resume" directly afterwards to |
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219 | resume timer processing. |
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220 | |
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221 | Effectively, all "timer" watchers will be delayed by the time spend |
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222 | between "suspend" and "resume", and all "periodic" watchers will be |
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223 | rescheduled (that is, they will lose any events that would have |
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224 | occured while suspended). |
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225 | |
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226 | After calling "suspend" you must not call *any* function on the |
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227 | given loop other than "resume", and you must not call "resume" |
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228 | without a previous call to "suspend". |
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229 | |
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230 | Calling "suspend"/"resume" has the side effect of updating the event |
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231 | loop time (see "now_update"). |
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232 | |
157 | $backend = EV::backend |
233 | $backend = EV::backend |
158 | $backend = $loop->backend |
234 | $backend = $loop->backend |
159 | Returns an integer describing the backend used by libev |
235 | Returns an integer describing the backend used by libev |
160 | (EV::BACKEND_SELECT or EV::BACKEND_EPOLL). |
236 | (EV::BACKEND_SELECT or EV::BACKEND_EPOLL). |
161 | |
237 | |
162 | EV::loop [$flags] |
238 | $active = EV::run [$flags] |
163 | $loop->loop ([$flags]) |
239 | $active = $loop->run ([$flags]) |
164 | Begin checking for events and calling callbacks. It returns when a |
240 | Begin checking for events and calling callbacks. It returns when a |
165 | callback calls EV::unloop. |
241 | callback calls EV::break or the flags are nonzero (in which case the |
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242 | return value is true) or when there are no active watchers which |
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243 | reference the loop (keepalive is true), in which case the return |
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244 | value will be false. The return value can generally be interpreted |
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245 | as "if true, there is more work left to do". |
166 | |
246 | |
167 | The $flags argument can be one of the following: |
247 | The $flags argument can be one of the following: |
168 | |
248 | |
169 | 0 as above |
249 | 0 as above |
170 | EV::LOOP_ONESHOT block at most once (wait, but do not loop) |
250 | EV::RUN_ONCE block at most once (wait, but do not loop) |
171 | EV::LOOP_NONBLOCK do not block at all (fetch/handle events but do not wait) |
251 | EV::RUN_NOWAIT do not block at all (fetch/handle events but do not wait) |
172 | |
252 | |
173 | EV::unloop [$how] |
253 | EV::break [$how] |
174 | $loop->unloop ([$how]) |
254 | $loop->break ([$how]) |
175 | When called with no arguments or an argument of EV::UNLOOP_ONE, |
255 | When called with no arguments or an argument of EV::BREAK_ONE, makes |
176 | makes the innermost call to EV::loop return. |
256 | the innermost call to EV::run return. |
177 | |
257 | |
178 | When called with an argument of EV::UNLOOP_ALL, all calls to |
258 | When called with an argument of EV::BREAK_ALL, all calls to EV::run |
179 | EV::loop will return as fast as possible. |
259 | will return as fast as possible. |
180 | |
260 | |
181 | $count = EV::loop_count |
261 | When called with an argument of EV::BREAK_CANCEL, any pending break |
182 | $count = $loop->loop_count |
262 | will be cancelled. |
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263 | |
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264 | $count = EV::iteration |
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265 | $count = $loop->iteration |
183 | Return the number of times the event loop has polled for new events. |
266 | Return the number of times the event loop has polled for new events. |
184 | Sometimes useful as a generation counter. |
267 | Sometimes useful as a generation counter. |
185 | |
268 | |
186 | EV::once $fh_or_undef, $events, $timeout, $cb->($revents) |
269 | EV::once $fh_or_undef, $events, $timeout, $cb->($revents) |
187 | $loop->once ($fh_or_undef, $events, $timeout, $cb->($revents)) |
270 | $loop->once ($fh_or_undef, $events, $timeout, $cb->($revents)) |
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193 | "EV::READ | EV::WRITE", indicating the type of I/O event you want to |
276 | "EV::READ | EV::WRITE", indicating the type of I/O event you want to |
194 | wait for. If you do not want to wait for some I/O event, specify |
277 | wait for. If you do not want to wait for some I/O event, specify |
195 | "undef" for $fh_or_undef and 0 for $events). |
278 | "undef" for $fh_or_undef and 0 for $events). |
196 | |
279 | |
197 | If timeout is "undef" or negative, then there will be no timeout. |
280 | If timeout is "undef" or negative, then there will be no timeout. |
198 | Otherwise a EV::timer with this value will be started. |
281 | Otherwise an "EV::timer" with this value will be started. |
199 | |
282 | |
200 | When an error occurs or either the timeout or I/O watcher triggers, |
283 | When an error occurs or either the timeout or I/O watcher triggers, |
201 | then the callback will be called with the received event set (in |
284 | then the callback will be called with the received event set (in |
202 | general you can expect it to be a combination of "EV::ERROR", |
285 | general you can expect it to be a combination of "EV::ERROR", |
203 | "EV::READ", "EV::WRITE" and "EV::TIMEOUT"). |
286 | "EV::READ", "EV::WRITE" and "EV::TIMER"). |
204 | |
287 | |
205 | EV::once doesn't return anything: the watchers stay active till |
288 | EV::once doesn't return anything: the watchers stay active till |
206 | either of them triggers, then they will be stopped and freed, and |
289 | either of them triggers, then they will be stopped and freed, and |
207 | the callback invoked. |
290 | the callback invoked. |
208 | |
291 | |
209 | EV::feed_fd_event ($fd, $revents) |
292 | EV::feed_fd_event $fd, $revents |
210 | $loop->feed_fd_event ($fd, $revents) |
293 | $loop->feed_fd_event ($fd, $revents) |
211 | Feed an event on a file descriptor into EV. EV will react to this |
294 | Feed an event on a file descriptor into EV. EV will react to this |
212 | call as if the readyness notifications specified by $revents (a |
295 | call as if the readyness notifications specified by $revents (a |
213 | combination of "EV::READ" and "EV::WRITE") happened on the file |
296 | combination of "EV::READ" and "EV::WRITE") happened on the file |
214 | descriptor $fd. |
297 | descriptor $fd. |
215 | |
298 | |
216 | EV::feed_signal_event ($signal) |
299 | EV::feed_signal_event $signal |
217 | Feed a signal event into EV. EV will react to this call as if the |
300 | Feed a signal event into the default loop. EV will react to this |
218 | signal specified by $signal had occured. |
301 | call as if the signal specified by $signal had occured. |
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302 | |
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303 | EV::feed_signal $signal |
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304 | Feed a signal event into EV - unlike "EV::feed_signal_event", this |
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305 | works regardless of which loop has registered the signal, and is |
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306 | mainly useful fro custom signal implementations. |
219 | |
307 | |
220 | EV::set_io_collect_interval $time |
308 | EV::set_io_collect_interval $time |
221 | $loop->set_io_collect_interval ($time) |
309 | $loop->set_io_collect_interval ($time) |
222 | EV::set_timeout_collect_interval $time |
310 | EV::set_timeout_collect_interval $time |
223 | $loop->set_timeout_collect_interval ($time) |
311 | $loop->set_timeout_collect_interval ($time) |
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226 | the libev documentation at |
314 | the libev documentation at |
227 | <http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#FUNCTIONS_CONT |
315 | <http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#FUNCTIONS_CONT |
228 | ROLLING_THE_EVENT_LOOP> (locally installed as EV::libev) for a more |
316 | ROLLING_THE_EVENT_LOOP> (locally installed as EV::libev) for a more |
229 | detailed discussion. |
317 | detailed discussion. |
230 | |
318 | |
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319 | $count = EV::pending_count |
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320 | $count = $loop->pending_count |
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321 | Returns the number of currently pending watchers. |
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322 | |
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323 | EV::invoke_pending |
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324 | $loop->invoke_pending |
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325 | Invoke all currently pending watchers. |
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326 | |
231 | WATCHER OBJECTS |
327 | WATCHER OBJECTS |
232 | A watcher is an object that gets created to record your interest in some |
328 | A watcher is an object that gets created to record your interest in some |
233 | event. For instance, if you want to wait for STDIN to become readable, |
329 | event. For instance, if you want to wait for STDIN to become readable, |
234 | you would create an EV::io watcher for that: |
330 | you would create an EV::io watcher for that: |
235 | |
331 | |
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245 | |
341 | |
246 | Each watcher type has its associated bit in revents, so you can use the |
342 | Each watcher type has its associated bit in revents, so you can use the |
247 | same callback for multiple watchers. The event mask is named after the |
343 | same callback for multiple watchers. The event mask is named after the |
248 | type, i.e. EV::child sets EV::CHILD, EV::prepare sets EV::PREPARE, |
344 | type, i.e. EV::child sets EV::CHILD, EV::prepare sets EV::PREPARE, |
249 | EV::periodic sets EV::PERIODIC and so on, with the exception of I/O |
345 | EV::periodic sets EV::PERIODIC and so on, with the exception of I/O |
250 | events (which can set both EV::READ and EV::WRITE bits), and EV::timer |
346 | events (which can set both EV::READ and EV::WRITE bits). |
251 | (which uses EV::TIMEOUT). |
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252 | |
347 | |
253 | In the rare case where one wants to create a watcher but not start it at |
348 | In the rare case where one wants to create a watcher but not start it at |
254 | the same time, each constructor has a variant with a trailing "_ns" in |
349 | the same time, each constructor has a variant with a trailing "_ns" in |
255 | its name, e.g. EV::io has a non-starting variant EV::io_ns and so on. |
350 | its name, e.g. EV::io has a non-starting variant EV::io_ns and so on. |
256 | |
351 | |
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319 | If the watcher is pending, this function clears its pending status |
414 | If the watcher is pending, this function clears its pending status |
320 | and returns its $revents bitset (as if its callback was invoked). If |
415 | and returns its $revents bitset (as if its callback was invoked). If |
321 | the watcher isn't pending it does nothing and returns 0. |
416 | the watcher isn't pending it does nothing and returns 0. |
322 | |
417 | |
323 | $previous_state = $w->keepalive ($bool) |
418 | $previous_state = $w->keepalive ($bool) |
324 | Normally, "EV::loop" will return when there are no active watchers |
419 | Normally, "EV::run" will return when there are no active watchers |
325 | (which is a "deadlock" because no progress can be made anymore). |
420 | (which is a "deadlock" because no progress can be made anymore). |
326 | This is convinient because it allows you to start your watchers (and |
421 | This is convenient because it allows you to start your watchers (and |
327 | your jobs), call "EV::loop" once and when it returns you know that |
422 | your jobs), call "EV::run" once and when it returns you know that |
328 | all your jobs are finished (or they forgot to register some watchers |
423 | all your jobs are finished (or they forgot to register some watchers |
329 | for their task :). |
424 | for their task :). |
330 | |
425 | |
331 | Sometimes, however, this gets in your way, for example when the |
426 | Sometimes, however, this gets in your way, for example when the |
332 | module that calls "EV::loop" (usually the main program) is not the |
427 | module that calls "EV::run" (usually the main program) is not the |
333 | same module as a long-living watcher (for example a DNS client |
428 | same module as a long-living watcher (for example a DNS client |
334 | module written by somebody else even). Then you might want any |
429 | module written by somebody else even). Then you might want any |
335 | outstanding requests to be handled, but you would not want to keep |
430 | outstanding requests to be handled, but you would not want to keep |
336 | "EV::loop" from returning just because you happen to have this |
431 | "EV::run" from returning just because you happen to have this |
337 | long-running UDP port watcher. |
432 | long-running UDP port watcher. |
338 | |
433 | |
339 | In this case you can clear the keepalive status, which means that |
434 | In this case you can clear the keepalive status, which means that |
340 | even though your watcher is active, it won't keep "EV::loop" from |
435 | even though your watcher is active, it won't keep "EV::run" from |
341 | returning. |
436 | returning. |
342 | |
437 | |
343 | The initial value for keepalive is true (enabled), and you can |
438 | The initial value for keepalive is true (enabled), and you can |
344 | change it any time. |
439 | change it any time. |
345 | |
440 | |
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387 | TIMER WATCHERS - relative and optionally repeating timeouts |
482 | TIMER WATCHERS - relative and optionally repeating timeouts |
388 | $w = EV::timer $after, $repeat, $callback |
483 | $w = EV::timer $after, $repeat, $callback |
389 | $w = EV::timer_ns $after, $repeat, $callback |
484 | $w = EV::timer_ns $after, $repeat, $callback |
390 | $w = $loop->timer ($after, $repeat, $callback) |
485 | $w = $loop->timer ($after, $repeat, $callback) |
391 | $w = $loop->timer_ns ($after, $repeat, $callback) |
486 | $w = $loop->timer_ns ($after, $repeat, $callback) |
392 | Calls the callback after $after seconds (which may be fractional). |
487 | Calls the callback after $after seconds (which may be fractional or |
393 | If $repeat is non-zero, the timer will be restarted (with the |
488 | negative). If $repeat is non-zero, the timer will be restarted (with |
394 | $repeat value as $after) after the callback returns. |
489 | the $repeat value as $after) after the callback returns. |
395 | |
490 | |
396 | This means that the callback would be called roughly after $after |
491 | This means that the callback would be called roughly after $after |
397 | seconds, and then every $repeat seconds. The timer does his best not |
492 | seconds, and then every $repeat seconds. The timer does his best not |
398 | to drift, but it will not invoke the timer more often then once per |
493 | to drift, but it will not invoke the timer more often then once per |
399 | event loop iteration, and might drift in other cases. If that isn't |
494 | event loop iteration, and might drift in other cases. If that isn't |
… | |
… | |
406 | the same time. |
501 | the same time. |
407 | |
502 | |
408 | The "timer_ns" variant doesn't start (activate) the newly created |
503 | The "timer_ns" variant doesn't start (activate) the newly created |
409 | watcher. |
504 | watcher. |
410 | |
505 | |
411 | $w->set ($after, $repeat) |
506 | $w->set ($after, $repeat = 0) |
412 | Reconfigures the watcher, see the constructor above for details. Can |
507 | Reconfigures the watcher, see the constructor above for details. Can |
413 | be called at any time. |
508 | be called at any time. |
414 | |
509 | |
415 | $w->again |
510 | $w->again |
|
|
511 | $w->again ($repeat) |
416 | Similar to the "start" method, but has special semantics for |
512 | Similar to the "start" method, but has special semantics for |
417 | repeating timers: |
513 | repeating timers: |
418 | |
514 | |
419 | If the timer is active and non-repeating, it will be stopped. |
515 | If the timer is active and non-repeating, it will be stopped. |
420 | |
516 | |
… | |
… | |
428 | |
524 | |
429 | This behaviour is useful when you have a timeout for some IO |
525 | This behaviour is useful when you have a timeout for some IO |
430 | operation. You create a timer object with the same value for $after |
526 | operation. You create a timer object with the same value for $after |
431 | and $repeat, and then, in the read/write watcher, run the "again" |
527 | and $repeat, and then, in the read/write watcher, run the "again" |
432 | method on the timeout. |
528 | method on the timeout. |
|
|
529 | |
|
|
530 | If called with a $repeat argument, then it uses this a timer repeat |
|
|
531 | value. |
|
|
532 | |
|
|
533 | $after = $w->remaining |
|
|
534 | Calculates and returns the remaining time till the timer will fire. |
433 | |
535 | |
434 | PERIODIC WATCHERS - to cron or not to cron? |
536 | PERIODIC WATCHERS - to cron or not to cron? |
435 | $w = EV::periodic $at, $interval, $reschedule_cb, $callback |
537 | $w = EV::periodic $at, $interval, $reschedule_cb, $callback |
436 | $w = EV::periodic_ns $at, $interval, $reschedule_cb, $callback |
538 | $w = EV::periodic_ns $at, $interval, $reschedule_cb, $callback |
437 | $w = $loop->periodic ($at, $interval, $reschedule_cb, $callback) |
539 | $w = $loop->periodic ($at, $interval, $reschedule_cb, $callback) |
… | |
… | |
454 | system time reaches or surpasses this time. |
556 | system time reaches or surpasses this time. |
455 | |
557 | |
456 | * repeating interval timer ($interval > 0, $reschedule_cb = 0) |
558 | * repeating interval timer ($interval > 0, $reschedule_cb = 0) |
457 | |
559 | |
458 | In this mode the watcher will always be scheduled to time out at |
560 | In this mode the watcher will always be scheduled to time out at |
459 | the next "$at + N * $interval" time (for some integer N) and |
561 | the next "$at + N * $interval" time (for the lowest integer N) |
460 | then repeat, regardless of any time jumps. |
562 | and then repeat, regardless of any time jumps. Note that, since |
|
|
563 | "N" can be negative, the first trigger can happen before $at. |
461 | |
564 | |
462 | This can be used to create timers that do not drift with respect |
565 | This can be used to create timers that do not drift with respect |
463 | to system time: |
566 | to system time: |
464 | |
567 | |
465 | my $hourly = EV::periodic 0, 3600, 0, sub { print "once/hour\n" }; |
568 | my $hourly = EV::periodic 0, 3600, 0, sub { print "once/hour\n" }; |
466 | |
569 | |
467 | That doesn't mean there will always be 3600 seconds in between |
570 | That doesn't mean there will always be 3600 seconds in between |
468 | triggers, but only that the the clalback will be called when the |
571 | triggers, but only that the the callback will be called when the |
469 | system time shows a full hour (UTC). |
572 | system time shows a full hour (UTC). |
470 | |
573 | |
471 | Another way to think about it (for the mathematically inclined) |
574 | Another way to think about it (for the mathematically inclined) |
472 | is that EV::periodic will try to run the callback in this mode |
575 | is that EV::periodic will try to run the callback in this mode |
473 | at the next possible time where "$time = $at (mod $interval)", |
576 | at the next possible time where "$time = $at (mod $interval)", |
… | |
… | |
481 | first, and the current time as second argument. |
584 | first, and the current time as second argument. |
482 | |
585 | |
483 | *This callback MUST NOT stop or destroy this or any other |
586 | *This callback MUST NOT stop or destroy this or any other |
484 | periodic watcher, ever, and MUST NOT call any event loop |
587 | periodic watcher, ever, and MUST NOT call any event loop |
485 | functions or methods*. If you need to stop it, return 1e30 and |
588 | functions or methods*. If you need to stop it, return 1e30 and |
486 | stop it afterwards. You may create and start a "EV::prepare" |
589 | stop it afterwards. You may create and start an "EV::prepare" |
487 | watcher for this task. |
590 | watcher for this task. |
488 | |
591 | |
489 | It must return the next time to trigger, based on the passed |
592 | It must return the next time to trigger, based on the passed |
490 | time value (that is, the lowest time value larger than or equal |
593 | time value (that is, the lowest time value larger than or equal |
491 | to to the second argument). It will usually be called just |
594 | to to the second argument). It will usually be called just |
492 | before the callback will be triggered, but might be called at |
595 | before the callback will be triggered, but might be called at |
493 | other times, too. |
596 | other times, too. |
494 | |
597 | |
495 | This can be used to create very complex timers, such as a timer |
598 | This can be used to create very complex timers, such as a timer |
496 | that triggers on each midnight, local time (actually 24 hours |
599 | that triggers on each midnight, local time (actually one day |
497 | after the last midnight, to keep the example simple. If you know |
600 | after the last midnight, to keep the example simple): |
498 | a way to do it correctly in about the same space (without |
|
|
499 | requiring elaborate modules), drop me a note :): |
|
|
500 | |
601 | |
501 | my $daily = EV::periodic 0, 0, sub { |
602 | my $daily = EV::periodic 0, 0, sub { |
502 | my ($w, $now) = @_; |
603 | my ($w, $now) = @_; |
503 | |
604 | |
504 | use Time::Local (); |
605 | use Time::Local (); |
505 | my (undef, undef, undef, $d, $m, $y) = localtime $now; |
606 | my (undef, undef, undef, $d, $m, $y) = localtime $now; |
506 | 86400 + Time::Local::timelocal 0, 0, 0, $d, $m, $y |
607 | Time::Local::timelocal_nocheck 0, 0, 0, $d + 1, $m, $y |
507 | }, sub { |
608 | }, sub { |
508 | print "it's midnight or likely shortly after, now\n"; |
609 | print "it's midnight or likely shortly after, now\n"; |
509 | }; |
610 | }; |
510 | |
611 | |
511 | The "periodic_ns" variant doesn't start (activate) the newly created |
612 | The "periodic_ns" variant doesn't start (activate) the newly created |
… | |
… | |
522 | Return the time that the watcher is expected to trigger next. |
623 | Return the time that the watcher is expected to trigger next. |
523 | |
624 | |
524 | SIGNAL WATCHERS - signal me when a signal gets signalled! |
625 | SIGNAL WATCHERS - signal me when a signal gets signalled! |
525 | $w = EV::signal $signal, $callback |
626 | $w = EV::signal $signal, $callback |
526 | $w = EV::signal_ns $signal, $callback |
627 | $w = EV::signal_ns $signal, $callback |
|
|
628 | $w = $loop->signal ($signal, $callback) |
|
|
629 | $w = $loop->signal_ns ($signal, $callback) |
527 | Call the callback when $signal is received (the signal can be |
630 | Call the callback when $signal is received (the signal can be |
528 | specified by number or by name, just as with "kill" or %SIG). |
631 | specified by number or by name, just as with "kill" or %SIG). |
|
|
632 | |
|
|
633 | Only one event loop can grab a given signal - attempting to grab the |
|
|
634 | same signal from two EV loops will crash the program immediately or |
|
|
635 | cause data corruption. |
529 | |
636 | |
530 | EV will grab the signal for the process (the kernel only allows one |
637 | EV will grab the signal for the process (the kernel only allows one |
531 | component to receive a signal at a time) when you start a signal |
638 | component to receive a signal at a time) when you start a signal |
532 | watcher, and removes it again when you stop it. Perl does the same |
639 | watcher, and removes it again when you stop it. Perl does the same |
533 | when you add/remove callbacks to %SIG, so watch out. |
640 | when you add/remove callbacks to %SIG, so watch out. |
… | |
… | |
707 | $w = $loop->check_ns ($callback) |
814 | $w = $loop->check_ns ($callback) |
708 | Call the callback just after the process wakes up again (after it |
815 | Call the callback just after the process wakes up again (after it |
709 | has gathered events), but before any other callbacks have been |
816 | has gathered events), but before any other callbacks have been |
710 | invoked. |
817 | invoked. |
711 | |
818 | |
712 | This is used to integrate other event-based software into the EV |
819 | This can be used to integrate other event-based software into the EV |
713 | mainloop: You register a prepare callback and in there, you create |
820 | mainloop: You register a prepare callback and in there, you create |
714 | io and timer watchers as required by the other software. Here is a |
821 | io and timer watchers as required by the other software. Here is a |
715 | real-world example of integrating Net::SNMP (with some details left |
822 | real-world example of integrating Net::SNMP (with some details left |
716 | out): |
823 | out): |
717 | |
824 | |
… | |
… | |
753 | watchers are destroyed before this can happen (remember EV::check |
860 | watchers are destroyed before this can happen (remember EV::check |
754 | gets called first). |
861 | gets called first). |
755 | |
862 | |
756 | The "check_ns" variant doesn't start (activate) the newly created |
863 | The "check_ns" variant doesn't start (activate) the newly created |
757 | watcher. |
864 | watcher. |
|
|
865 | |
|
|
866 | EV::CHECK constant issues |
|
|
867 | Like all other watcher types, there is a bitmask constant for use in |
|
|
868 | $revents and other places. The "EV::CHECK" is special as it has the |
|
|
869 | same name as the "CHECK" sub called by Perl. This doesn't cause big |
|
|
870 | issues on newer perls (beginning with 5.8.9), but it means thatthe |
|
|
871 | constant must be *inlined*, i.e. runtime calls will not work. That |
|
|
872 | means that as long as you always "use EV" and then "EV::CHECK" you |
|
|
873 | are on the safe side. |
758 | |
874 | |
759 | FORK WATCHERS - the audacity to resume the event loop after a fork |
875 | FORK WATCHERS - the audacity to resume the event loop after a fork |
760 | Fork watchers are called when a "fork ()" was detected. The invocation |
876 | Fork watchers are called when a "fork ()" was detected. The invocation |
761 | is done before the event loop blocks next and before "check" watchers |
877 | is done before the event loop blocks next and before "check" watchers |
762 | are being called, and only in the child after the fork. |
878 | are being called, and only in the child after the fork. |
… | |
… | |
783 | |
899 | |
784 | In short, this watcher is most useful on BSD systems without working |
900 | In short, this watcher is most useful on BSD systems without working |
785 | kqueue to still be able to handle a large number of sockets: |
901 | kqueue to still be able to handle a large number of sockets: |
786 | |
902 | |
787 | my $socket_loop; |
903 | my $socket_loop; |
788 | |
904 | |
789 | # check wether we use SELECT or POLL _and_ KQUEUE is supported |
905 | # check wether we use SELECT or POLL _and_ KQUEUE is supported |
790 | if ( |
906 | if ( |
791 | (EV::backend & (EV::BACKEND_POLL | EV::BACKEND_SELECT)) |
907 | (EV::backend & (EV::BACKEND_POLL | EV::BACKEND_SELECT)) |
792 | && (EV::supported_backends & EV::embeddable_backends & EV::BACKEND_KQUEUE) |
908 | && (EV::supported_backends & EV::embeddable_backends & EV::BACKEND_KQUEUE) |
793 | ) { |
909 | ) { |
794 | # use kqueue for sockets |
910 | # use kqueue for sockets |
795 | $socket_loop = new EV::Loop EV::BACKEND_KQUEUE | EV::FLAG_NOENV; |
911 | $socket_loop = new EV::Loop EV::BACKEND_KQUEUE | EV::FLAG_NOENV; |
796 | } |
912 | } |
797 | |
913 | |
798 | # use the default loop otherwise |
914 | # use the default loop otherwise |
799 | $socket_loop ||= EV::default_loop; |
915 | $socket_loop ||= EV::default_loop; |
800 | |
916 | |
801 | $w = EV::embed $otherloop[, $callback] |
917 | $w = EV::embed $otherloop[, $callback] |
802 | $w = EV::embed_ns $otherloop[, $callback] |
918 | $w = EV::embed_ns $otherloop[, $callback] |
803 | $w = $loop->embed ($otherloop[, $callback]) |
919 | $w = $loop->embed ($otherloop[, $callback]) |
… | |
… | |
810 | The "embed_ns" variant doesn't start (activate) the newly created |
926 | The "embed_ns" variant doesn't start (activate) the newly created |
811 | watcher. |
927 | watcher. |
812 | |
928 | |
813 | ASYNC WATCHERS - how to wake up another event loop |
929 | ASYNC WATCHERS - how to wake up another event loop |
814 | Async watchers are provided by EV, but have little use in perl directly, |
930 | Async watchers are provided by EV, but have little use in perl directly, |
815 | as perl neither supports threads nor direct access to signal handlers or |
931 | as perl neither supports threads running in parallel nor direct access |
816 | other contexts where they could be of value. |
932 | to signal handlers or other contexts where they could be of value. |
817 | |
933 | |
818 | It is, however, possible to use them from the XS level. |
934 | It is, however, possible to use them from the XS level. |
819 | |
935 | |
820 | Please see the libev documentation for further details. |
936 | Please see the libev documentation for further details. |
821 | |
937 | |
822 | $w = EV::async $callback |
938 | $w = EV::async $callback |
823 | $w = EV::async_ns $callback |
939 | $w = EV::async_ns $callback |
|
|
940 | $w = $loop->async ($callback) |
|
|
941 | $w = $loop->async_ns ($callback) |
824 | $w->send |
942 | $w->send |
825 | $bool = $w->async_pending |
943 | $bool = $w->async_pending |
|
|
944 | |
|
|
945 | CLEANUP WATCHERS - how to clean up when the event loop goes away |
|
|
946 | Cleanup watchers are not supported on the Perl level, they can only be |
|
|
947 | used via XS currently. |
826 | |
948 | |
827 | PERL SIGNALS |
949 | PERL SIGNALS |
828 | While Perl signal handling (%SIG) is not affected by EV, the behaviour |
950 | While Perl signal handling (%SIG) is not affected by EV, the behaviour |
829 | with EV is as the same as any other C library: Perl-signals will only be |
951 | with EV is as the same as any other C library: Perl-signals will only be |
830 | handled when Perl runs, which means your signal handler might be invoked |
952 | handled when Perl runs, which means your signal handler might be invoked |
… | |
… | |
840 | my $async_check = EV::check sub { }; |
962 | my $async_check = EV::check sub { }; |
841 | |
963 | |
842 | This ensures that perl gets into control for a short time to handle any |
964 | This ensures that perl gets into control for a short time to handle any |
843 | pending signals, and also ensures (slightly) slower overall operation. |
965 | pending signals, and also ensures (slightly) slower overall operation. |
844 | |
966 | |
845 | THREADS |
967 | ITHREADS |
846 | Threads are not supported by this module in any way. Perl pseudo-threads |
968 | Ithreads are not supported by this module in any way. Perl |
847 | is evil stuff and must die. As soon as Perl gains real threads I will |
969 | pseudo-threads is evil stuff and must die. Real threads as provided by |
848 | work on thread support for it. |
970 | Coro are fully supported (and enhanced support is available via |
|
|
971 | Coro::EV). |
849 | |
972 | |
850 | FORK |
973 | FORK |
851 | Most of the "improved" event delivering mechanisms of modern operating |
974 | Most of the "improved" event delivering mechanisms of modern operating |
852 | systems have quite a few problems with fork(2) (to put it bluntly: it is |
975 | systems have quite a few problems with fork(2) (to put it bluntly: it is |
853 | not supported and usually destructive). Libev makes it possible to work |
976 | not supported and usually destructive). Libev makes it possible to work |
… | |
… | |
863 | |
986 | |
864 | On win32, there is no notion of fork so all this doesn't apply, of |
987 | On win32, there is no notion of fork so all this doesn't apply, of |
865 | course. |
988 | course. |
866 | |
989 | |
867 | SEE ALSO |
990 | SEE ALSO |
868 | EV::ADNS (asynchronous DNS), Glib::EV (makes Glib/Gtk2 use EV as event |
991 | EV::MakeMaker - MakeMaker interface to XS API, EV::ADNS (asynchronous |
869 | loop), EV::Glib (embed Glib into EV), Coro::EV (efficient coroutines |
992 | DNS), Glib::EV (makes Glib/Gtk2 use EV as event loop), EV::Glib (embed |
870 | with EV), Net::SNMP::EV (asynchronous SNMP), AnyEvent for event-loop |
993 | Glib into EV), Coro::EV (efficient thread integration), Net::SNMP::EV |
871 | agnostic and portable event driven programming. |
994 | (asynchronous SNMP), AnyEvent for event-loop agnostic and portable event |
|
|
995 | driven programming. |
872 | |
996 | |
873 | AUTHOR |
997 | AUTHOR |
874 | Marc Lehmann <schmorp@schmorp.de> |
998 | Marc Lehmann <schmorp@schmorp.de> |
875 | http://home.schmorp.de/ |
999 | http://home.schmorp.de/ |
876 | |
1000 | |