… | |
… | |
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 | }; |
|
|
43 | |
|
|
44 | # STAT CHANGES |
|
|
45 | my $w = EV::stat "/etc/passwd", 10, sub { |
|
|
46 | my ($w, $revents) = @_; |
|
|
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 |
|
|
62 | about in any case because it has much more detailed information. |
56 | |
63 | |
57 | BASIC INTERFACE |
64 | BASIC INTERFACE |
58 | $EV::DIED |
65 | $EV::DIED |
59 | Must contain a reference to a function that is called when a |
66 | Must contain a reference to a function that is called when a |
60 | callback throws an exception (with $@ containing thr error). The |
67 | callback throws an exception (with $@ containing thr error). The |
… | |
… | |
89 | makes the innermost call to EV::loop return. |
96 | makes the innermost call to EV::loop return. |
90 | |
97 | |
91 | When called with an argument of EV::UNLOOP_ALL, all calls to |
98 | When called with an argument of EV::UNLOOP_ALL, all calls to |
92 | EV::loop will return as fast as possible. |
99 | EV::loop will return as fast as possible. |
93 | |
100 | |
|
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101 | $count = EV::loop_count |
|
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102 | Return the number of times the event loop has polled for new events. |
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103 | Sometiems useful as a generation counter. |
|
|
104 | |
94 | EV::once $fh_or_undef, $events, $timeout, $cb->($revents) |
105 | EV::once $fh_or_undef, $events, $timeout, $cb->($revents) |
95 | This function rolls together an I/O and a timer watcher for a single |
106 | 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. |
107 | one-shot event without the need for managing a watcher object. |
97 | |
108 | |
98 | If $fh_or_undef is a filehandle or file descriptor, then $events |
109 | If $fh_or_undef is a filehandle or file descriptor, then $events |
… | |
… | |
111 | |
122 | |
112 | EV::once doesn't return anything: the watchers stay active till |
123 | EV::once doesn't return anything: the watchers stay active till |
113 | either of them triggers, then they will be stopped and freed, and |
124 | either of them triggers, then they will be stopped and freed, and |
114 | the callback invoked. |
125 | the callback invoked. |
115 | |
126 | |
116 | WATCHER |
127 | WATCHER OBJECTS |
117 | A watcher is an object that gets created to record your interest in some |
128 | 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, |
129 | event. For instance, if you want to wait for STDIN to become readable, |
119 | you would create an EV::io watcher for that: |
130 | you would create an EV::io watcher for that: |
120 | |
131 | |
121 | my $watcher = EV::io *STDIN, EV::READ, sub { |
132 | my $watcher = EV::io *STDIN, EV::READ, sub { |
… | |
… | |
129 | received events. |
140 | received events. |
130 | |
141 | |
131 | Each watcher type has its associated bit in revents, so you can use the |
142 | 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 |
143 | 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, |
144 | 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 |
145 | 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 |
146 | events (which can set both EV::READ and EV::WRITE bits), and EV::timer |
136 | (which uses EV::TIMEOUT). |
147 | (which uses EV::TIMEOUT). |
137 | |
148 | |
138 | In the rare case where one wants to create a watcher but not start it at |
149 | 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 |
150 | the same time, each constructor has a variant with a trailing "_ns" in |
… | |
… | |
145 | |
156 | |
146 | Also, all methods changing some aspect of a watcher (->set, ->priority, |
157 | 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, |
158 | ->fh and so on) automatically stop and start it again if it is active, |
148 | which means pending events get lost. |
159 | which means pending events get lost. |
149 | |
160 | |
150 | WATCHER TYPES |
161 | COMMON WATCHER METHODS |
151 | Now lets move to the existing watcher types and asociated methods. |
162 | This section lists methods common to all watchers. |
152 | |
|
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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). |
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157 | |
163 | |
158 | $w->start |
164 | $w->start |
159 | Starts a watcher if it isn't active already. Does nothing to an |
165 | 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 |
166 | already active watcher. By default, all watchers start out in the |
161 | active state (see the description of the "_ns" variants if you need |
167 | active state (see the description of the "_ns" variants if you need |
162 | stopped watchers). |
168 | stopped watchers). |
163 | |
169 | |
164 | $w->stop |
170 | $w->stop |
165 | Stop a watcher if it is active. Also clear any pending events |
171 | 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 |
172 | (events that have been received but that didn't yet result in a |
167 | callback invocation), regardless of wether the watcher was active or |
173 | callback invocation), regardless of whether the watcher was active |
168 | not. |
174 | or not. |
169 | |
175 | |
170 | $bool = $w->is_active |
176 | $bool = $w->is_active |
171 | Returns true if the watcher is active, false otherwise. |
177 | Returns true if the watcher is active, false otherwise. |
172 | |
178 | |
173 | $current_data = $w->data |
179 | $current_data = $w->data |
… | |
… | |
222 | returning. |
228 | returning. |
223 | |
229 | |
224 | The initial value for keepalive is true (enabled), and you cna |
230 | The initial value for keepalive is true (enabled), and you cna |
225 | change it any time. |
231 | change it any time. |
226 | |
232 | |
227 | Example: Register an IO watcher for some UDP socket but do not keep |
233 | 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. |
234 | the event loop from running just because of that watcher. |
229 | |
235 | |
230 | my $udp_socket = ... |
236 | my $udp_socket = ... |
231 | my $udp_watcher = EV::io $udp_socket, EV::READ, sub { ... }; |
237 | my $udp_watcher = EV::io $udp_socket, EV::READ, sub { ... }; |
232 | $udp_watcher->keepalive (0); |
238 | $udp_watcher->keepalive (0); |
233 | |
239 | |
|
|
240 | WATCHER TYPES |
|
|
241 | Each of the following subsections describes a single watcher type. |
|
|
242 | |
|
|
243 | I/O WATCHERS - is this file descriptor readable or writable? |
234 | $w = EV::io $fileno_or_fh, $eventmask, $callback |
244 | $w = EV::io $fileno_or_fh, $eventmask, $callback |
235 | $w = EV::io_ns $fileno_or_fh, $eventmask, $callback |
245 | $w = EV::io_ns $fileno_or_fh, $eventmask, $callback |
236 | As long as the returned watcher object is alive, call the $callback |
246 | As long as the returned watcher object is alive, call the $callback |
237 | when the events specified in $eventmask. |
247 | when at least one of events specified in $eventmask occurs. |
238 | |
248 | |
239 | The $eventmask can be one or more of these constants ORed together: |
249 | The $eventmask can be one or more of these constants ORed together: |
240 | |
250 | |
241 | EV::READ wait until read() wouldn't block anymore |
251 | EV::READ wait until read() wouldn't block anymore |
242 | EV::WRITE wait until write() wouldn't block anymore |
252 | EV::WRITE wait until write() wouldn't block anymore |
… | |
… | |
254 | |
264 | |
255 | $current_eventmask = $w->events |
265 | $current_eventmask = $w->events |
256 | $old_eventmask = $w->events ($new_eventmask) |
266 | $old_eventmask = $w->events ($new_eventmask) |
257 | Returns the previously set event mask and optionally set a new one. |
267 | Returns the previously set event mask and optionally set a new one. |
258 | |
268 | |
|
|
269 | TIMER WATCHERS - relative and optionally repeating timeouts |
259 | $w = EV::timer $after, $repeat, $callback |
270 | $w = EV::timer $after, $repeat, $callback |
260 | $w = EV::timer_ns $after, $repeat, $callback |
271 | $w = EV::timer_ns $after, $repeat, $callback |
261 | Calls the callback after $after seconds (which may be fractional). |
272 | Calls the callback after $after seconds (which may be fractional). |
262 | If $repeat is non-zero, the timer will be restarted (with the |
273 | If $repeat is non-zero, the timer will be restarted (with the |
263 | $repeat value as $after) after the callback returns. |
274 | $repeat value as $after) after the callback returns. |
… | |
… | |
277 | The "timer_ns" variant doesn't start (activate) the newly created |
288 | The "timer_ns" variant doesn't start (activate) the newly created |
278 | watcher. |
289 | watcher. |
279 | |
290 | |
280 | $w->set ($after, $repeat) |
291 | $w->set ($after, $repeat) |
281 | Reconfigures the watcher, see the constructor above for details. Can |
292 | Reconfigures the watcher, see the constructor above for details. Can |
282 | be at any time. |
293 | be called at any time. |
283 | |
294 | |
284 | $w->again |
295 | $w->again |
285 | Similar to the "start" method, but has special semantics for |
296 | Similar to the "start" method, but has special semantics for |
286 | repeating timers: |
297 | repeating timers: |
287 | |
298 | |
… | |
… | |
298 | This behaviour is useful when you have a timeout for some IO |
309 | 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 |
310 | 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" |
311 | and $repeat, and then, in the read/write watcher, run the "again" |
301 | method on the timeout. |
312 | method on the timeout. |
302 | |
313 | |
|
|
314 | PERIODIC WATCHERS - to cron or not to cron? |
303 | $w = EV::periodic $at, $interval, $reschedule_cb, $callback |
315 | $w = EV::periodic $at, $interval, $reschedule_cb, $callback |
304 | $w = EV::periodic_ns $at, $interval, $reschedule_cb, $callback |
316 | $w = EV::periodic_ns $at, $interval, $reschedule_cb, $callback |
305 | Similar to EV::timer, but is not based on relative timeouts but on |
317 | Similar to EV::timer, but is not based on relative timeouts but on |
306 | absolute times. Apart from creating "simple" timers that trigger |
318 | absolute times. Apart from creating "simple" timers that trigger |
307 | "at" the specified time, it can also be used for non-drifting |
319 | "at" the specified time, it can also be used for non-drifting |
… | |
… | |
372 | The "periodic_ns" variant doesn't start (activate) the newly created |
384 | The "periodic_ns" variant doesn't start (activate) the newly created |
373 | watcher. |
385 | watcher. |
374 | |
386 | |
375 | $w->set ($at, $interval, $reschedule_cb) |
387 | $w->set ($at, $interval, $reschedule_cb) |
376 | Reconfigures the watcher, see the constructor above for details. Can |
388 | Reconfigures the watcher, see the constructor above for details. Can |
377 | be at any time. |
389 | be called at any time. |
378 | |
390 | |
379 | $w->again |
391 | $w->again |
380 | Simply stops and starts the watcher again. |
392 | Simply stops and starts the watcher again. |
381 | |
393 | |
|
|
394 | SIGNAL WATCHERS - signal me when a signal gets signalled! |
382 | $w = EV::signal $signal, $callback |
395 | $w = EV::signal $signal, $callback |
383 | $w = EV::signal_ns $signal, $callback |
396 | $w = EV::signal_ns $signal, $callback |
384 | Call the callback when $signal is received (the signal can be |
397 | Call the callback when $signal is received (the signal can be |
385 | specified by number or by name, just as with kill or %SIG). |
398 | specified by number or by name, just as with "kill" or %SIG). |
386 | |
399 | |
387 | EV will grab the signal for the process (the kernel only allows one |
400 | 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 |
401 | 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 |
402 | watcher, and removes it again when you stop it. Perl does the same |
390 | when you add/remove callbacks to %SIG, so watch out. |
403 | when you add/remove callbacks to %SIG, so watch out. |
… | |
… | |
394 | The "signal_ns" variant doesn't start (activate) the newly created |
407 | The "signal_ns" variant doesn't start (activate) the newly created |
395 | watcher. |
408 | watcher. |
396 | |
409 | |
397 | $w->set ($signal) |
410 | $w->set ($signal) |
398 | Reconfigures the watcher, see the constructor above for details. Can |
411 | Reconfigures the watcher, see the constructor above for details. Can |
399 | be at any time. |
412 | be called at any time. |
400 | |
413 | |
401 | $current_signum = $w->signal |
414 | $current_signum = $w->signal |
402 | $old_signum = $w->signal ($new_signal) |
415 | $old_signum = $w->signal ($new_signal) |
403 | Returns the previously set signal (always as a number not name) and |
416 | Returns the previously set signal (always as a number not name) and |
404 | optionally set a new one. |
417 | optionally set a new one. |
405 | |
418 | |
|
|
419 | CHILD WATCHERS - watch out for process status changes |
406 | $w = EV::child $pid, $callback |
420 | $w = EV::child $pid, $callback |
407 | $w = EV::child_ns $pid, $callback |
421 | $w = EV::child_ns $pid, $callback |
408 | Call the callback when a status change for pid $pid (or any pid if |
422 | 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 |
423 | $pid is 0) has been received. More precisely: when the process |
410 | receives a SIGCHLD, EV will fetch the outstanding exit/wait status |
424 | receives a "SIGCHLD", EV will fetch the outstanding exit/wait status |
411 | for all changed/zombie children and call the callback. |
425 | for all changed/zombie children and call the callback. |
412 | |
426 | |
413 | You can access both status and pid by using the "rstatus" and "rpid" |
427 | It is valid (and fully supported) to install a child watcher after a |
|
|
428 | child has exited but before the event loop has started its next |
|
|
429 | iteration (for example, first you "fork", then the new child process |
|
|
430 | might exit, and only then do you install a child watcher in the |
|
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431 | parent for the new pid). |
|
|
432 | |
|
|
433 | You can access both exit (or tracing) status and pid by using the |
414 | methods on the watcher object. |
434 | "rstatus" and "rpid" methods on the watcher object. |
415 | |
435 | |
416 | You can have as many pid watchers per pid as you want. |
436 | You can have as many pid watchers per pid as you want, they will all |
|
|
437 | be called. |
417 | |
438 | |
418 | The "child_ns" variant doesn't start (activate) the newly created |
439 | The "child_ns" variant doesn't start (activate) the newly created |
419 | watcher. |
440 | watcher. |
420 | |
441 | |
421 | $w->set ($pid) |
442 | $w->set ($pid) |
422 | Reconfigures the watcher, see the constructor above for details. Can |
443 | Reconfigures the watcher, see the constructor above for details. Can |
423 | be at any time. |
444 | be called at any time. |
424 | |
445 | |
425 | $current_pid = $w->pid |
446 | $current_pid = $w->pid |
426 | $old_pid = $w->pid ($new_pid) |
447 | $old_pid = $w->pid ($new_pid) |
427 | Returns the previously set process id and optionally set a new one. |
448 | Returns the previously set process id and optionally set a new one. |
428 | |
449 | |
… | |
… | |
432 | |
453 | |
433 | $pid = $w->rpid |
454 | $pid = $w->rpid |
434 | Return the pid of the awaited child (useful when you have installed |
455 | Return the pid of the awaited child (useful when you have installed |
435 | a watcher for all pids). |
456 | a watcher for all pids). |
436 | |
457 | |
|
|
458 | STAT WATCHERS - did the file attributes just change? |
|
|
459 | $w = EV::stat $path, $interval, $callback |
|
|
460 | $w = EV::stat_ns $path, $interval, $callback |
|
|
461 | Call the callback when a file status change has been detected on |
|
|
462 | $path. The $path does not need to exist, changing from "path exists" |
|
|
463 | to "path does not exist" is a status change like any other. |
|
|
464 | |
|
|
465 | The $interval is a recommended polling interval for systems where |
|
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466 | OS-supported change notifications don't exist or are not supported. |
|
|
467 | If you use 0 then an unspecified default is used (which is highly |
|
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468 | recommended!), which is to be expected to be around five seconds |
|
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469 | usually. |
|
|
470 | |
|
|
471 | This watcher type is not meant for massive numbers of stat watchers, |
|
|
472 | as even with OS-supported change notifications, this can be |
|
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473 | resource-intensive. |
|
|
474 | |
|
|
475 | The "stat_ns" variant doesn't start (activate) the newly created |
|
|
476 | watcher. |
|
|
477 | |
|
|
478 | ... = $w->stat |
|
|
479 | This call is very similar to the perl "stat" built-in: It stats |
|
|
480 | (using "lstat") the path specified in the watcher and sets perls |
|
|
481 | stat cache (as well as EV's idea of the current stat values) to the |
|
|
482 | values found. |
|
|
483 | |
|
|
484 | In scalar context, a boolean is return indicating success or failure |
|
|
485 | of the stat. In list context, the same 13-value list as with stat is |
|
|
486 | returned (except that the blksize and blocks fields are not |
|
|
487 | reliable). |
|
|
488 | |
|
|
489 | In the case of an error, errno is set to "ENOENT" (regardless of the |
|
|
490 | actual error value) and the "nlink" value is forced to zero (if the |
|
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491 | stat was successful then nlink is guaranteed to be non-zero). |
|
|
492 | |
|
|
493 | See also the next two entries for more info. |
|
|
494 | |
|
|
495 | ... = $w->attr |
|
|
496 | Just like "$w->stat", but without the initial stat'ing: this returns |
|
|
497 | the values most recently detected by EV. See the next entry for more |
|
|
498 | info. |
|
|
499 | |
|
|
500 | ... = $w->prev |
|
|
501 | Just like "$w->stat", but without the initial stat'ing: this returns |
|
|
502 | the previous set of values, before the change. |
|
|
503 | |
|
|
504 | That is, when the watcher callback is invoked, "$w->prev" will be |
|
|
505 | set to the values found *before* a change was detected, while |
|
|
506 | "$w->attr" returns the values found leading to the change detection. |
|
|
507 | The difference (if any) between "prev" and "attr" is what triggered |
|
|
508 | the callback. |
|
|
509 | |
|
|
510 | If you did something to the filesystem object and do not want to |
|
|
511 | trigger yet another change, you can call "stat" to update EV's idea |
|
|
512 | of what the current attributes are. |
|
|
513 | |
|
|
514 | $w->set ($path, $interval) |
|
|
515 | Reconfigures the watcher, see the constructor above for details. Can |
|
|
516 | be called at any time. |
|
|
517 | |
|
|
518 | $current_path = $w->path |
|
|
519 | $old_path = $w->path ($new_path) |
|
|
520 | Returns the previously set path and optionally set a new one. |
|
|
521 | |
|
|
522 | $current_interval = $w->interval |
|
|
523 | $old_interval = $w->interval ($new_interval) |
|
|
524 | Returns the previously set interval and optionally set a new one. |
|
|
525 | Can be used to query the actual interval used. |
|
|
526 | |
|
|
527 | IDLE WATCHERS - when you've got nothing better to do... |
437 | $w = EV::idle $callback |
528 | $w = EV::idle $callback |
438 | $w = EV::idle_ns $callback |
529 | $w = EV::idle_ns $callback |
439 | Call the callback when there are no pending io, timer/periodic, |
530 | Call the callback when there are no other pending watchers of the |
440 | signal or child events, i.e. when the process is idle. |
531 | same or higher priority (excluding check, prepare and other idle |
|
|
532 | watchers of the same or lower priority, of course). They are called |
|
|
533 | idle watchers because when the watcher is the highest priority |
|
|
534 | pending event in the process, the process is considered to be idle |
|
|
535 | at that priority. |
|
|
536 | |
|
|
537 | If you want a watcher that is only ever called when *no* other |
|
|
538 | events are outstanding you have to set the priority to "EV::MINPRI". |
441 | |
539 | |
442 | The process will not block as long as any idle watchers are active, |
540 | The process will not block as long as any idle watchers are active, |
443 | and they will be called repeatedly until stopped. |
541 | and they will be called repeatedly until stopped. |
444 | |
542 | |
|
|
543 | For example, if you have idle watchers at priority 0 and 1, and an |
|
|
544 | I/O watcher at priority 0, then the idle watcher at priority 1 and |
|
|
545 | the I/O watcher will always run when ready. Only when the idle |
|
|
546 | watcher at priority 1 is stopped and the I/O watcher at priority 0 |
|
|
547 | is not pending with the 0-priority idle watcher be invoked. |
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548 | |
445 | The "idle_ns" variant doesn't start (activate) the newly created |
549 | The "idle_ns" variant doesn't start (activate) the newly created |
446 | watcher. |
550 | watcher. |
447 | |
551 | |
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552 | PREPARE WATCHERS - customise your event loop! |
448 | $w = EV::prepare $callback |
553 | $w = EV::prepare $callback |
449 | $w = EV::prepare_ns $callback |
554 | $w = EV::prepare_ns $callback |
450 | Call the callback just before the process would block. You can still |
555 | Call the callback just before the process would block. You can still |
451 | create/modify any watchers at this point. |
556 | create/modify any watchers at this point. |
452 | |
557 | |
453 | See the EV::check watcher, below, for explanations and an example. |
558 | See the EV::check watcher, below, for explanations and an example. |
454 | |
559 | |
455 | The "prepare_ns" variant doesn't start (activate) the newly created |
560 | The "prepare_ns" variant doesn't start (activate) the newly created |
456 | watcher. |
561 | watcher. |
457 | |
562 | |
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563 | CHECK WATCHERS - customise your event loop even more! |
458 | $w = EV::check $callback |
564 | $w = EV::check $callback |
459 | $w = EV::check_ns $callback |
565 | $w = EV::check_ns $callback |
460 | Call the callback just after the process wakes up again (after it |
566 | Call the callback just after the process wakes up again (after it |
461 | has gathered events), but before any other callbacks have been |
567 | has gathered events), but before any other callbacks have been |
462 | invoked. |
568 | invoked. |
… | |
… | |
475 | or return; |
581 | or return; |
476 | |
582 | |
477 | # make the dispatcher handle any outstanding stuff |
583 | # make the dispatcher handle any outstanding stuff |
478 | ... not shown |
584 | ... not shown |
479 | |
585 | |
480 | # create an IO watcher for each and every socket |
586 | # create an I/O watcher for each and every socket |
481 | @snmp_watcher = ( |
587 | @snmp_watcher = ( |
482 | (map { EV::io $_, EV::READ, sub { } } |
588 | (map { EV::io $_, EV::READ, sub { } } |
483 | keys %{ $dispatcher->{_descriptors} }), |
589 | keys %{ $dispatcher->{_descriptors} }), |
484 | |
590 | |
485 | EV::timer +($event->[Net::SNMP::Dispatcher::_ACTIVE] |
591 | EV::timer +($event->[Net::SNMP::Dispatcher::_ACTIVE] |
… | |
… | |
505 | watchers are destroyed before this cna happen (remember EV::check |
611 | watchers are destroyed before this cna happen (remember EV::check |
506 | gets called first). |
612 | gets called first). |
507 | |
613 | |
508 | The "check_ns" variant doesn't start (activate) the newly created |
614 | The "check_ns" variant doesn't start (activate) the newly created |
509 | watcher. |
615 | watcher. |
|
|
616 | |
|
|
617 | FORK WATCHERS - the audacity to resume the event loop after a fork |
|
|
618 | Fork watchers are called when a "fork ()" was detected. The invocation |
|
|
619 | is done before the event loop blocks next and before "check" watchers |
|
|
620 | are being called, and only in the child after the fork. |
|
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621 | |
|
|
622 | $w = EV::fork $callback |
|
|
623 | $w = EV::fork_ns $callback |
|
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624 | Call the callback before the event loop is resumed in the child |
|
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625 | process after a fork. |
|
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626 | |
|
|
627 | The "fork_ns" variant doesn't start (activate) the newly created |
|
|
628 | watcher. |
|
|
629 | |
|
|
630 | PERL SIGNALS |
|
|
631 | While Perl signal handling (%SIG) is not affected by EV, the behaviour |
|
|
632 | with EV is as the same as any other C library: Perl-signals will only be |
|
|
633 | handled when Perl runs, which means your signal handler might be invoked |
|
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634 | only the next time an event callback is invoked. |
|
|
635 | |
|
|
636 | The solution is to use EV signal watchers (see "EV::signal"), which will |
|
|
637 | ensure proper operations with regards to other event watchers. |
|
|
638 | |
|
|
639 | If you cannot do this for whatever reason, you can also force a watcher |
|
|
640 | to be called on every event loop iteration by installing a "EV::check" |
|
|
641 | watcher: |
|
|
642 | |
|
|
643 | my $async_check = EV::check sub { }; |
|
|
644 | |
|
|
645 | This ensures that perl shortly gets into control for a short time, and |
|
|
646 | also ensures slower overall operation. |
510 | |
647 | |
511 | THREADS |
648 | THREADS |
512 | Threads are not supported by this module in any way. Perl pseudo-threads |
649 | 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 |
650 | is evil stuff and must die. As soon as Perl gains real threads I will |
514 | work on thread support for it. |
651 | work on thread support for it. |
… | |
… | |
529 | |
666 | |
530 | On win32, there is no notion of fork so all this doesn't apply, of |
667 | On win32, there is no notion of fork so all this doesn't apply, of |
531 | course. |
668 | course. |
532 | |
669 | |
533 | SEE ALSO |
670 | SEE ALSO |
534 | L<EV::DNS>. |
671 | EV::ADNS (asynchronous dns), Glib::EV (makes Glib/Gtk2 use EV as event |
|
|
672 | loop), Coro::EV (efficient coroutines with EV). |
535 | |
673 | |
536 | AUTHOR |
674 | AUTHOR |
537 | Marc Lehmann <schmorp@schmorp.de> |
675 | Marc Lehmann <schmorp@schmorp.de> |
538 | http://home.schmorp.de/ |
676 | http://home.schmorp.de/ |
539 | |
677 | |