… | |
… | |
127 | .\} |
127 | .\} |
128 | .rm #[ #] #H #V #F C |
128 | .rm #[ #] #H #V #F C |
129 | .\" ======================================================================== |
129 | .\" ======================================================================== |
130 | .\" |
130 | .\" |
131 | .IX Title ""<STANDARD INPUT>" 1" |
131 | .IX Title ""<STANDARD INPUT>" 1" |
132 | .TH "<STANDARD INPUT>" 1 "2007-11-24" "perl v5.8.8" "User Contributed Perl Documentation" |
132 | .TH "<STANDARD INPUT>" 1 "2007-11-28" "perl v5.8.8" "User Contributed Perl Documentation" |
133 | .SH "NAME" |
133 | .SH "NAME" |
134 | libev \- a high performance full\-featured event loop written in C |
134 | libev \- a high performance full\-featured event loop written in C |
135 | .SH "SYNOPSIS" |
135 | .SH "SYNOPSIS" |
136 | .IX Header "SYNOPSIS" |
136 | .IX Header "SYNOPSIS" |
137 | .Vb 1 |
137 | .Vb 1 |
138 | \& #include <ev.h> |
138 | \& #include <ev.h> |
139 | .Ve |
139 | .Ve |
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140 | .SH "EXAMPLE PROGRAM" |
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141 | .IX Header "EXAMPLE PROGRAM" |
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142 | .Vb 1 |
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143 | \& #include <ev.h> |
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144 | .Ve |
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145 | .PP |
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146 | .Vb 2 |
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147 | \& ev_io stdin_watcher; |
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148 | \& ev_timer timeout_watcher; |
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149 | .Ve |
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150 | .PP |
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151 | .Vb 8 |
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152 | \& /* called when data readable on stdin */ |
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153 | \& static void |
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154 | \& stdin_cb (EV_P_ struct ev_io *w, int revents) |
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155 | \& { |
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156 | \& /* puts ("stdin ready"); */ |
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157 | \& ev_io_stop (EV_A_ w); /* just a syntax example */ |
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158 | \& ev_unloop (EV_A_ EVUNLOOP_ALL); /* leave all loop calls */ |
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159 | \& } |
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160 | .Ve |
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161 | .PP |
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162 | .Vb 6 |
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163 | \& static void |
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164 | \& timeout_cb (EV_P_ struct ev_timer *w, int revents) |
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165 | \& { |
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166 | \& /* puts ("timeout"); */ |
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167 | \& ev_unloop (EV_A_ EVUNLOOP_ONE); /* leave one loop call */ |
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168 | \& } |
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169 | .Ve |
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170 | .PP |
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171 | .Vb 4 |
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172 | \& int |
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173 | \& main (void) |
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174 | \& { |
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175 | \& struct ev_loop *loop = ev_default_loop (0); |
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176 | .Ve |
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177 | .PP |
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178 | .Vb 3 |
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179 | \& /* initialise an io watcher, then start it */ |
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180 | \& ev_io_init (&stdin_watcher, stdin_cb, /*STDIN_FILENO*/ 0, EV_READ); |
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181 | \& ev_io_start (loop, &stdin_watcher); |
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182 | .Ve |
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183 | .PP |
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184 | .Vb 3 |
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185 | \& /* simple non-repeating 5.5 second timeout */ |
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186 | \& ev_timer_init (&timeout_watcher, timeout_cb, 5.5, 0.); |
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187 | \& ev_timer_start (loop, &timeout_watcher); |
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188 | .Ve |
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189 | .PP |
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190 | .Vb 2 |
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191 | \& /* loop till timeout or data ready */ |
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192 | \& ev_loop (loop, 0); |
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193 | .Ve |
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194 | .PP |
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195 | .Vb 2 |
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196 | \& return 0; |
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197 | \& } |
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198 | .Ve |
140 | .SH "DESCRIPTION" |
199 | .SH "DESCRIPTION" |
141 | .IX Header "DESCRIPTION" |
200 | .IX Header "DESCRIPTION" |
142 | Libev is an event loop: you register interest in certain events (such as a |
201 | Libev is an event loop: you register interest in certain events (such as a |
143 | file descriptor being readable or a timeout occuring), and it will manage |
202 | file descriptor being readable or a timeout occuring), and it will manage |
144 | these event sources and provide your program with events. |
203 | these event sources and provide your program with events. |
… | |
… | |
151 | watchers\fR, which are relatively small C structures you initialise with the |
210 | watchers\fR, which are relatively small C structures you initialise with the |
152 | details of the event, and then hand it over to libev by \fIstarting\fR the |
211 | details of the event, and then hand it over to libev by \fIstarting\fR the |
153 | watcher. |
212 | watcher. |
154 | .SH "FEATURES" |
213 | .SH "FEATURES" |
155 | .IX Header "FEATURES" |
214 | .IX Header "FEATURES" |
156 | Libev supports select, poll, the linux-specific epoll and the bsd-specific |
215 | Libev supports \f(CW\*(C`select\*(C'\fR, \f(CW\*(C`poll\*(C'\fR, the Linux-specific \f(CW\*(C`epoll\*(C'\fR, the |
157 | kqueue mechanisms for file descriptor events, relative timers, absolute |
216 | BSD-specific \f(CW\*(C`kqueue\*(C'\fR and the Solaris-specific event port mechanisms |
158 | timers with customised rescheduling, signal events, process status change |
217 | for file descriptor events (\f(CW\*(C`ev_io\*(C'\fR), the Linux \f(CW\*(C`inotify\*(C'\fR interface |
159 | events (related to \s-1SIGCHLD\s0), and event watchers dealing with the event |
218 | (for \f(CW\*(C`ev_stat\*(C'\fR), relative timers (\f(CW\*(C`ev_timer\*(C'\fR), absolute timers |
160 | loop mechanism itself (idle, prepare and check watchers). It also is quite |
219 | with customised rescheduling (\f(CW\*(C`ev_periodic\*(C'\fR), synchronous signals |
161 | fast (see this benchmark comparing |
220 | (\f(CW\*(C`ev_signal\*(C'\fR), process status change events (\f(CW\*(C`ev_child\*(C'\fR), and event |
162 | it to libevent for example). |
221 | watchers dealing with the event loop mechanism itself (\f(CW\*(C`ev_idle\*(C'\fR, |
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222 | \&\f(CW\*(C`ev_embed\*(C'\fR, \f(CW\*(C`ev_prepare\*(C'\fR and \f(CW\*(C`ev_check\*(C'\fR watchers) as well as |
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223 | file watchers (\f(CW\*(C`ev_stat\*(C'\fR) and even limited support for fork events |
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224 | (\f(CW\*(C`ev_fork\*(C'\fR). |
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225 | .PP |
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226 | It also is quite fast (see this |
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227 | benchmark comparing it to libevent |
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228 | for example). |
163 | .SH "CONVENTIONS" |
229 | .SH "CONVENTIONS" |
164 | .IX Header "CONVENTIONS" |
230 | .IX Header "CONVENTIONS" |
165 | Libev is very configurable. In this manual the default configuration |
231 | Libev is very configurable. In this manual the default configuration will |
166 | will be described, which supports multiple event loops. For more info |
232 | be described, which supports multiple event loops. For more info about |
167 | about various configuration options please have a look at the file |
233 | various configuration options please have a look at \fB\s-1EMBED\s0\fR section in |
168 | \&\fI\s-1README\s0.embed\fR in the libev distribution. If libev was configured without |
234 | this manual. If libev was configured without support for multiple event |
169 | support for multiple event loops, then all functions taking an initial |
235 | loops, then all functions taking an initial argument of name \f(CW\*(C`loop\*(C'\fR |
170 | argument of name \f(CW\*(C`loop\*(C'\fR (which is always of type \f(CW\*(C`struct ev_loop *\*(C'\fR) |
236 | (which is always of type \f(CW\*(C`struct ev_loop *\*(C'\fR) will not have this argument. |
171 | will not have this argument. |
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172 | .SH "TIME REPRESENTATION" |
237 | .SH "TIME REPRESENTATION" |
173 | .IX Header "TIME REPRESENTATION" |
238 | .IX Header "TIME REPRESENTATION" |
174 | Libev represents time as a single floating point number, representing the |
239 | Libev represents time as a single floating point number, representing the |
175 | (fractional) number of seconds since the (\s-1POSIX\s0) epoch (somewhere near |
240 | (fractional) number of seconds since the (\s-1POSIX\s0) epoch (somewhere near |
176 | the beginning of 1970, details are complicated, don't ask). This type is |
241 | the beginning of 1970, details are complicated, don't ask). This type is |
… | |
… | |
201 | Usually, it's a good idea to terminate if the major versions mismatch, |
266 | Usually, it's a good idea to terminate if the major versions mismatch, |
202 | as this indicates an incompatible change. Minor versions are usually |
267 | as this indicates an incompatible change. Minor versions are usually |
203 | compatible to older versions, so a larger minor version alone is usually |
268 | compatible to older versions, so a larger minor version alone is usually |
204 | not a problem. |
269 | not a problem. |
205 | .Sp |
270 | .Sp |
206 | Example: make sure we haven't accidentally been linked against the wrong |
271 | Example: Make sure we haven't accidentally been linked against the wrong |
207 | version: |
272 | version. |
208 | .Sp |
273 | .Sp |
209 | .Vb 3 |
274 | .Vb 3 |
210 | \& assert (("libev version mismatch", |
275 | \& assert (("libev version mismatch", |
211 | \& ev_version_major () == EV_VERSION_MAJOR |
276 | \& ev_version_major () == EV_VERSION_MAJOR |
212 | \& && ev_version_minor () >= EV_VERSION_MINOR)); |
277 | \& && ev_version_minor () >= EV_VERSION_MINOR)); |
… | |
… | |
242 | recommended ones. |
307 | recommended ones. |
243 | .Sp |
308 | .Sp |
244 | See the description of \f(CW\*(C`ev_embed\*(C'\fR watchers for more info. |
309 | See the description of \f(CW\*(C`ev_embed\*(C'\fR watchers for more info. |
245 | .IP "ev_set_allocator (void *(*cb)(void *ptr, long size))" 4 |
310 | .IP "ev_set_allocator (void *(*cb)(void *ptr, long size))" 4 |
246 | .IX Item "ev_set_allocator (void *(*cb)(void *ptr, long size))" |
311 | .IX Item "ev_set_allocator (void *(*cb)(void *ptr, long size))" |
247 | Sets the allocation function to use (the prototype is similar to the |
312 | Sets the allocation function to use (the prototype is similar \- the |
248 | realloc C function, the semantics are identical). It is used to allocate |
313 | semantics is identical \- to the realloc C function). It is used to |
249 | and free memory (no surprises here). If it returns zero when memory |
314 | allocate and free memory (no surprises here). If it returns zero when |
250 | needs to be allocated, the library might abort or take some potentially |
315 | memory needs to be allocated, the library might abort or take some |
251 | destructive action. The default is your system realloc function. |
316 | potentially destructive action. The default is your system realloc |
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317 | function. |
252 | .Sp |
318 | .Sp |
253 | You could override this function in high-availability programs to, say, |
319 | You could override this function in high-availability programs to, say, |
254 | free some memory if it cannot allocate memory, to use a special allocator, |
320 | free some memory if it cannot allocate memory, to use a special allocator, |
255 | or even to sleep a while and retry until some memory is available. |
321 | or even to sleep a while and retry until some memory is available. |
256 | .Sp |
322 | .Sp |
257 | Example: replace the libev allocator with one that waits a bit and then |
323 | Example: Replace the libev allocator with one that waits a bit and then |
258 | retries: better than mine). |
324 | retries). |
259 | .Sp |
325 | .Sp |
260 | .Vb 6 |
326 | .Vb 6 |
261 | \& static void * |
327 | \& static void * |
262 | \& persistent_realloc (void *ptr, long size) |
328 | \& persistent_realloc (void *ptr, size_t size) |
263 | \& { |
329 | \& { |
264 | \& for (;;) |
330 | \& for (;;) |
265 | \& { |
331 | \& { |
266 | \& void *newptr = realloc (ptr, size); |
332 | \& void *newptr = realloc (ptr, size); |
267 | .Ve |
333 | .Ve |
… | |
… | |
289 | callback is set, then libev will expect it to remedy the sitution, no |
355 | callback is set, then libev will expect it to remedy the sitution, no |
290 | matter what, when it returns. That is, libev will generally retry the |
356 | matter what, when it returns. That is, libev will generally retry the |
291 | requested operation, or, if the condition doesn't go away, do bad stuff |
357 | requested operation, or, if the condition doesn't go away, do bad stuff |
292 | (such as abort). |
358 | (such as abort). |
293 | .Sp |
359 | .Sp |
294 | Example: do the same thing as libev does internally: |
360 | Example: This is basically the same thing that libev does internally, too. |
295 | .Sp |
361 | .Sp |
296 | .Vb 6 |
362 | .Vb 6 |
297 | \& static void |
363 | \& static void |
298 | \& fatal_error (const char *msg) |
364 | \& fatal_error (const char *msg) |
299 | \& { |
365 | \& { |
… | |
… | |
448 | Similar to \f(CW\*(C`ev_default_loop\*(C'\fR, but always creates a new event loop that is |
514 | Similar to \f(CW\*(C`ev_default_loop\*(C'\fR, but always creates a new event loop that is |
449 | always distinct from the default loop. Unlike the default loop, it cannot |
515 | always distinct from the default loop. Unlike the default loop, it cannot |
450 | handle signal and child watchers, and attempts to do so will be greeted by |
516 | handle signal and child watchers, and attempts to do so will be greeted by |
451 | undefined behaviour (or a failed assertion if assertions are enabled). |
517 | undefined behaviour (or a failed assertion if assertions are enabled). |
452 | .Sp |
518 | .Sp |
453 | Example: try to create a event loop that uses epoll and nothing else. |
519 | Example: Try to create a event loop that uses epoll and nothing else. |
454 | .Sp |
520 | .Sp |
455 | .Vb 3 |
521 | .Vb 3 |
456 | \& struct ev_loop *epoller = ev_loop_new (EVBACKEND_EPOLL | EVFLAG_NOENV); |
522 | \& struct ev_loop *epoller = ev_loop_new (EVBACKEND_EPOLL | EVFLAG_NOENV); |
457 | \& if (!epoller) |
523 | \& if (!epoller) |
458 | \& fatal ("no epoll found here, maybe it hides under your chair"); |
524 | \& fatal ("no epoll found here, maybe it hides under your chair"); |
… | |
… | |
556 | \& be handled here by queueing them when their watcher gets executed. |
622 | \& be handled here by queueing them when their watcher gets executed. |
557 | \& - If ev_unloop has been called or EVLOOP_ONESHOT or EVLOOP_NONBLOCK |
623 | \& - If ev_unloop has been called or EVLOOP_ONESHOT or EVLOOP_NONBLOCK |
558 | \& were used, return, otherwise continue with step *. |
624 | \& were used, return, otherwise continue with step *. |
559 | .Ve |
625 | .Ve |
560 | .Sp |
626 | .Sp |
561 | Example: queue some jobs and then loop until no events are outsanding |
627 | Example: Queue some jobs and then loop until no events are outsanding |
562 | anymore. |
628 | anymore. |
563 | .Sp |
629 | .Sp |
564 | .Vb 4 |
630 | .Vb 4 |
565 | \& ... queue jobs here, make sure they register event watchers as long |
631 | \& ... queue jobs here, make sure they register event watchers as long |
566 | \& ... as they still have work to do (even an idle watcher will do..) |
632 | \& ... as they still have work to do (even an idle watcher will do..) |
… | |
… | |
588 | visible to the libev user and should not keep \f(CW\*(C`ev_loop\*(C'\fR from exiting if |
654 | visible to the libev user and should not keep \f(CW\*(C`ev_loop\*(C'\fR from exiting if |
589 | no event watchers registered by it are active. It is also an excellent |
655 | no event watchers registered by it are active. It is also an excellent |
590 | way to do this for generic recurring timers or from within third-party |
656 | way to do this for generic recurring timers or from within third-party |
591 | libraries. Just remember to \fIunref after start\fR and \fIref before stop\fR. |
657 | libraries. Just remember to \fIunref after start\fR and \fIref before stop\fR. |
592 | .Sp |
658 | .Sp |
593 | Example: create a signal watcher, but keep it from keeping \f(CW\*(C`ev_loop\*(C'\fR |
659 | Example: Create a signal watcher, but keep it from keeping \f(CW\*(C`ev_loop\*(C'\fR |
594 | running when nothing else is active. |
660 | running when nothing else is active. |
595 | .Sp |
661 | .Sp |
596 | .Vb 4 |
662 | .Vb 4 |
597 | \& struct dv_signal exitsig; |
663 | \& struct ev_signal exitsig; |
598 | \& ev_signal_init (&exitsig, sig_cb, SIGINT); |
664 | \& ev_signal_init (&exitsig, sig_cb, SIGINT); |
599 | \& ev_signal_start (myloop, &exitsig); |
665 | \& ev_signal_start (loop, &exitsig); |
600 | \& evf_unref (myloop); |
666 | \& evf_unref (loop); |
601 | .Ve |
667 | .Ve |
602 | .Sp |
668 | .Sp |
603 | Example: for some weird reason, unregister the above signal handler again. |
669 | Example: For some weird reason, unregister the above signal handler again. |
604 | .Sp |
670 | .Sp |
605 | .Vb 2 |
671 | .Vb 2 |
606 | \& ev_ref (myloop); |
672 | \& ev_ref (loop); |
607 | \& ev_signal_stop (myloop, &exitsig); |
673 | \& ev_signal_stop (loop, &exitsig); |
608 | .Ve |
674 | .Ve |
609 | .SH "ANATOMY OF A WATCHER" |
675 | .SH "ANATOMY OF A WATCHER" |
610 | .IX Header "ANATOMY OF A WATCHER" |
676 | .IX Header "ANATOMY OF A WATCHER" |
611 | A watcher is a structure that you create and register to record your |
677 | A watcher is a structure that you create and register to record your |
612 | interest in some event. For instance, if you want to wait for \s-1STDIN\s0 to |
678 | interest in some event. For instance, if you want to wait for \s-1STDIN\s0 to |
… | |
… | |
684 | The signal specified in the \f(CW\*(C`ev_signal\*(C'\fR watcher has been received by a thread. |
750 | The signal specified in the \f(CW\*(C`ev_signal\*(C'\fR watcher has been received by a thread. |
685 | .ie n .IP """EV_CHILD""" 4 |
751 | .ie n .IP """EV_CHILD""" 4 |
686 | .el .IP "\f(CWEV_CHILD\fR" 4 |
752 | .el .IP "\f(CWEV_CHILD\fR" 4 |
687 | .IX Item "EV_CHILD" |
753 | .IX Item "EV_CHILD" |
688 | The pid specified in the \f(CW\*(C`ev_child\*(C'\fR watcher has received a status change. |
754 | The pid specified in the \f(CW\*(C`ev_child\*(C'\fR watcher has received a status change. |
|
|
755 | .ie n .IP """EV_STAT""" 4 |
|
|
756 | .el .IP "\f(CWEV_STAT\fR" 4 |
|
|
757 | .IX Item "EV_STAT" |
|
|
758 | The path specified in the \f(CW\*(C`ev_stat\*(C'\fR watcher changed its attributes somehow. |
689 | .ie n .IP """EV_IDLE""" 4 |
759 | .ie n .IP """EV_IDLE""" 4 |
690 | .el .IP "\f(CWEV_IDLE\fR" 4 |
760 | .el .IP "\f(CWEV_IDLE\fR" 4 |
691 | .IX Item "EV_IDLE" |
761 | .IX Item "EV_IDLE" |
692 | The \f(CW\*(C`ev_idle\*(C'\fR watcher has determined that you have nothing better to do. |
762 | The \f(CW\*(C`ev_idle\*(C'\fR watcher has determined that you have nothing better to do. |
693 | .ie n .IP """EV_PREPARE""" 4 |
763 | .ie n .IP """EV_PREPARE""" 4 |
… | |
… | |
703 | \&\f(CW\*(C`ev_loop\*(C'\fR has gathered them, but before it invokes any callbacks for any |
773 | \&\f(CW\*(C`ev_loop\*(C'\fR has gathered them, but before it invokes any callbacks for any |
704 | received events. Callbacks of both watcher types can start and stop as |
774 | received events. Callbacks of both watcher types can start and stop as |
705 | many watchers as they want, and all of them will be taken into account |
775 | many watchers as they want, and all of them will be taken into account |
706 | (for example, a \f(CW\*(C`ev_prepare\*(C'\fR watcher might start an idle watcher to keep |
776 | (for example, a \f(CW\*(C`ev_prepare\*(C'\fR watcher might start an idle watcher to keep |
707 | \&\f(CW\*(C`ev_loop\*(C'\fR from blocking). |
777 | \&\f(CW\*(C`ev_loop\*(C'\fR from blocking). |
|
|
778 | .ie n .IP """EV_EMBED""" 4 |
|
|
779 | .el .IP "\f(CWEV_EMBED\fR" 4 |
|
|
780 | .IX Item "EV_EMBED" |
|
|
781 | The embedded event loop specified in the \f(CW\*(C`ev_embed\*(C'\fR watcher needs attention. |
|
|
782 | .ie n .IP """EV_FORK""" 4 |
|
|
783 | .el .IP "\f(CWEV_FORK\fR" 4 |
|
|
784 | .IX Item "EV_FORK" |
|
|
785 | The event loop has been resumed in the child process after fork (see |
|
|
786 | \&\f(CW\*(C`ev_fork\*(C'\fR). |
708 | .ie n .IP """EV_ERROR""" 4 |
787 | .ie n .IP """EV_ERROR""" 4 |
709 | .el .IP "\f(CWEV_ERROR\fR" 4 |
788 | .el .IP "\f(CWEV_ERROR\fR" 4 |
710 | .IX Item "EV_ERROR" |
789 | .IX Item "EV_ERROR" |
711 | An unspecified error has occured, the watcher has been stopped. This might |
790 | An unspecified error has occured, the watcher has been stopped. This might |
712 | happen because the watcher could not be properly started because libev |
791 | happen because the watcher could not be properly started because libev |
… | |
… | |
779 | Returns a true value iff the watcher is pending, (i.e. it has outstanding |
858 | Returns a true value iff the watcher is pending, (i.e. it has outstanding |
780 | events but its callback has not yet been invoked). As long as a watcher |
859 | events but its callback has not yet been invoked). As long as a watcher |
781 | is pending (but not active) you must not call an init function on it (but |
860 | is pending (but not active) you must not call an init function on it (but |
782 | \&\f(CW\*(C`ev_TYPE_set\*(C'\fR is safe) and you must make sure the watcher is available to |
861 | \&\f(CW\*(C`ev_TYPE_set\*(C'\fR is safe) and you must make sure the watcher is available to |
783 | libev (e.g. you cnanot \f(CW\*(C`free ()\*(C'\fR it). |
862 | libev (e.g. you cnanot \f(CW\*(C`free ()\*(C'\fR it). |
784 | .IP "callback = ev_cb (ev_TYPE *watcher)" 4 |
863 | .IP "callback ev_cb (ev_TYPE *watcher)" 4 |
785 | .IX Item "callback = ev_cb (ev_TYPE *watcher)" |
864 | .IX Item "callback ev_cb (ev_TYPE *watcher)" |
786 | Returns the callback currently set on the watcher. |
865 | Returns the callback currently set on the watcher. |
787 | .IP "ev_cb_set (ev_TYPE *watcher, callback)" 4 |
866 | .IP "ev_cb_set (ev_TYPE *watcher, callback)" 4 |
788 | .IX Item "ev_cb_set (ev_TYPE *watcher, callback)" |
867 | .IX Item "ev_cb_set (ev_TYPE *watcher, callback)" |
789 | Change the callback. You can change the callback at virtually any time |
868 | Change the callback. You can change the callback at virtually any time |
790 | (modulo threads). |
869 | (modulo threads). |
… | |
… | |
816 | \& struct my_io *w = (struct my_io *)w_; |
895 | \& struct my_io *w = (struct my_io *)w_; |
817 | \& ... |
896 | \& ... |
818 | \& } |
897 | \& } |
819 | .Ve |
898 | .Ve |
820 | .PP |
899 | .PP |
821 | More interesting and less C\-conformant ways of catsing your callback type |
900 | More interesting and less C\-conformant ways of casting your callback type |
822 | have been omitted.... |
901 | instead have been omitted. |
|
|
902 | .PP |
|
|
903 | Another common scenario is having some data structure with multiple |
|
|
904 | watchers: |
|
|
905 | .PP |
|
|
906 | .Vb 6 |
|
|
907 | \& struct my_biggy |
|
|
908 | \& { |
|
|
909 | \& int some_data; |
|
|
910 | \& ev_timer t1; |
|
|
911 | \& ev_timer t2; |
|
|
912 | \& } |
|
|
913 | .Ve |
|
|
914 | .PP |
|
|
915 | In this case getting the pointer to \f(CW\*(C`my_biggy\*(C'\fR is a bit more complicated, |
|
|
916 | you need to use \f(CW\*(C`offsetof\*(C'\fR: |
|
|
917 | .PP |
|
|
918 | .Vb 1 |
|
|
919 | \& #include <stddef.h> |
|
|
920 | .Ve |
|
|
921 | .PP |
|
|
922 | .Vb 6 |
|
|
923 | \& static void |
|
|
924 | \& t1_cb (EV_P_ struct ev_timer *w, int revents) |
|
|
925 | \& { |
|
|
926 | \& struct my_biggy big = (struct my_biggy * |
|
|
927 | \& (((char *)w) - offsetof (struct my_biggy, t1)); |
|
|
928 | \& } |
|
|
929 | .Ve |
|
|
930 | .PP |
|
|
931 | .Vb 6 |
|
|
932 | \& static void |
|
|
933 | \& t2_cb (EV_P_ struct ev_timer *w, int revents) |
|
|
934 | \& { |
|
|
935 | \& struct my_biggy big = (struct my_biggy * |
|
|
936 | \& (((char *)w) - offsetof (struct my_biggy, t2)); |
|
|
937 | \& } |
|
|
938 | .Ve |
823 | .SH "WATCHER TYPES" |
939 | .SH "WATCHER TYPES" |
824 | .IX Header "WATCHER TYPES" |
940 | .IX Header "WATCHER TYPES" |
825 | This section describes each watcher in detail, but will not repeat |
941 | This section describes each watcher in detail, but will not repeat |
826 | information given in the last section. |
942 | information given in the last section. Any initialisation/set macros, |
|
|
943 | functions and members specific to the watcher type are explained. |
|
|
944 | .PP |
|
|
945 | Members are additionally marked with either \fI[read\-only]\fR, meaning that, |
|
|
946 | while the watcher is active, you can look at the member and expect some |
|
|
947 | sensible content, but you must not modify it (you can modify it while the |
|
|
948 | watcher is stopped to your hearts content), or \fI[read\-write]\fR, which |
|
|
949 | means you can expect it to have some sensible content while the watcher |
|
|
950 | is active, but you can also modify it. Modifying it may not do something |
|
|
951 | sensible or take immediate effect (or do anything at all), but libev will |
|
|
952 | not crash or malfunction in any way. |
827 | .ie n .Sh """ev_io"" \- is this file descriptor readable or writable?" |
953 | .ie n .Sh """ev_io"" \- is this file descriptor readable or writable?" |
828 | .el .Sh "\f(CWev_io\fP \- is this file descriptor readable or writable?" |
954 | .el .Sh "\f(CWev_io\fP \- is this file descriptor readable or writable?" |
829 | .IX Subsection "ev_io - is this file descriptor readable or writable?" |
955 | .IX Subsection "ev_io - is this file descriptor readable or writable?" |
830 | I/O watchers check whether a file descriptor is readable or writable |
956 | I/O watchers check whether a file descriptor is readable or writable |
831 | in each iteration of the event loop, or, more precisely, when reading |
957 | in each iteration of the event loop, or, more precisely, when reading |
… | |
… | |
871 | .IX Item "ev_io_set (ev_io *, int fd, int events)" |
997 | .IX Item "ev_io_set (ev_io *, int fd, int events)" |
872 | .PD |
998 | .PD |
873 | Configures an \f(CW\*(C`ev_io\*(C'\fR watcher. The \f(CW\*(C`fd\*(C'\fR is the file descriptor to |
999 | Configures an \f(CW\*(C`ev_io\*(C'\fR watcher. The \f(CW\*(C`fd\*(C'\fR is the file descriptor to |
874 | rceeive events for and events is either \f(CW\*(C`EV_READ\*(C'\fR, \f(CW\*(C`EV_WRITE\*(C'\fR or |
1000 | rceeive events for and events is either \f(CW\*(C`EV_READ\*(C'\fR, \f(CW\*(C`EV_WRITE\*(C'\fR or |
875 | \&\f(CW\*(C`EV_READ | EV_WRITE\*(C'\fR to receive the given events. |
1001 | \&\f(CW\*(C`EV_READ | EV_WRITE\*(C'\fR to receive the given events. |
|
|
1002 | .IP "int fd [read\-only]" 4 |
|
|
1003 | .IX Item "int fd [read-only]" |
|
|
1004 | The file descriptor being watched. |
|
|
1005 | .IP "int events [read\-only]" 4 |
|
|
1006 | .IX Item "int events [read-only]" |
|
|
1007 | The events being watched. |
876 | .PP |
1008 | .PP |
877 | Example: call \f(CW\*(C`stdin_readable_cb\*(C'\fR when \s-1STDIN_FILENO\s0 has become, well |
1009 | Example: Call \f(CW\*(C`stdin_readable_cb\*(C'\fR when \s-1STDIN_FILENO\s0 has become, well |
878 | readable, but only once. Since it is likely line\-buffered, you could |
1010 | readable, but only once. Since it is likely line\-buffered, you could |
879 | attempt to read a whole line in the callback: |
1011 | attempt to read a whole line in the callback. |
880 | .PP |
1012 | .PP |
881 | .Vb 6 |
1013 | .Vb 6 |
882 | \& static void |
1014 | \& static void |
883 | \& stdin_readable_cb (struct ev_loop *loop, struct ev_io *w, int revents) |
1015 | \& stdin_readable_cb (struct ev_loop *loop, struct ev_io *w, int revents) |
884 | \& { |
1016 | \& { |
… | |
… | |
945 | .Sp |
1077 | .Sp |
946 | If the timer is repeating, either start it if necessary (with the repeat |
1078 | If the timer is repeating, either start it if necessary (with the repeat |
947 | value), or reset the running timer to the repeat value. |
1079 | value), or reset the running timer to the repeat value. |
948 | .Sp |
1080 | .Sp |
949 | This sounds a bit complicated, but here is a useful and typical |
1081 | This sounds a bit complicated, but here is a useful and typical |
950 | example: Imagine you have a tcp connection and you want a so-called idle |
1082 | example: Imagine you have a tcp connection and you want a so-called |
951 | timeout, that is, you want to be called when there have been, say, 60 |
1083 | idle timeout, that is, you want to be called when there have been, |
952 | seconds of inactivity on the socket. The easiest way to do this is to |
1084 | say, 60 seconds of inactivity on the socket. The easiest way to do |
953 | configure an \f(CW\*(C`ev_timer\*(C'\fR with after=repeat=60 and calling ev_timer_again each |
1085 | this is to configure an \f(CW\*(C`ev_timer\*(C'\fR with \f(CW\*(C`after\*(C'\fR=\f(CW\*(C`repeat\*(C'\fR=\f(CW60\fR and calling |
954 | time you successfully read or write some data. If you go into an idle |
1086 | \&\f(CW\*(C`ev_timer_again\*(C'\fR each time you successfully read or write some data. If |
955 | state where you do not expect data to travel on the socket, you can stop |
1087 | you go into an idle state where you do not expect data to travel on the |
956 | the timer, and again will automatically restart it if need be. |
1088 | socket, you can stop the timer, and again will automatically restart it if |
|
|
1089 | need be. |
|
|
1090 | .Sp |
|
|
1091 | You can also ignore the \f(CW\*(C`after\*(C'\fR value and \f(CW\*(C`ev_timer_start\*(C'\fR altogether |
|
|
1092 | and only ever use the \f(CW\*(C`repeat\*(C'\fR value: |
|
|
1093 | .Sp |
|
|
1094 | .Vb 8 |
|
|
1095 | \& ev_timer_init (timer, callback, 0., 5.); |
|
|
1096 | \& ev_timer_again (loop, timer); |
|
|
1097 | \& ... |
|
|
1098 | \& timer->again = 17.; |
|
|
1099 | \& ev_timer_again (loop, timer); |
|
|
1100 | \& ... |
|
|
1101 | \& timer->again = 10.; |
|
|
1102 | \& ev_timer_again (loop, timer); |
|
|
1103 | .Ve |
|
|
1104 | .Sp |
|
|
1105 | This is more efficient then stopping/starting the timer eahc time you want |
|
|
1106 | to modify its timeout value. |
|
|
1107 | .IP "ev_tstamp repeat [read\-write]" 4 |
|
|
1108 | .IX Item "ev_tstamp repeat [read-write]" |
|
|
1109 | The current \f(CW\*(C`repeat\*(C'\fR value. Will be used each time the watcher times out |
|
|
1110 | or \f(CW\*(C`ev_timer_again\*(C'\fR is called and determines the next timeout (if any), |
|
|
1111 | which is also when any modifications are taken into account. |
957 | .PP |
1112 | .PP |
958 | Example: create a timer that fires after 60 seconds. |
1113 | Example: Create a timer that fires after 60 seconds. |
959 | .PP |
1114 | .PP |
960 | .Vb 5 |
1115 | .Vb 5 |
961 | \& static void |
1116 | \& static void |
962 | \& one_minute_cb (struct ev_loop *loop, struct ev_timer *w, int revents) |
1117 | \& one_minute_cb (struct ev_loop *loop, struct ev_timer *w, int revents) |
963 | \& { |
1118 | \& { |
… | |
… | |
969 | \& struct ev_timer mytimer; |
1124 | \& struct ev_timer mytimer; |
970 | \& ev_timer_init (&mytimer, one_minute_cb, 60., 0.); |
1125 | \& ev_timer_init (&mytimer, one_minute_cb, 60., 0.); |
971 | \& ev_timer_start (loop, &mytimer); |
1126 | \& ev_timer_start (loop, &mytimer); |
972 | .Ve |
1127 | .Ve |
973 | .PP |
1128 | .PP |
974 | Example: create a timeout timer that times out after 10 seconds of |
1129 | Example: Create a timeout timer that times out after 10 seconds of |
975 | inactivity. |
1130 | inactivity. |
976 | .PP |
1131 | .PP |
977 | .Vb 5 |
1132 | .Vb 5 |
978 | \& static void |
1133 | \& static void |
979 | \& timeout_cb (struct ev_loop *loop, struct ev_timer *w, int revents) |
1134 | \& timeout_cb (struct ev_loop *loop, struct ev_timer *w, int revents) |
… | |
… | |
1093 | .IX Item "ev_periodic_again (loop, ev_periodic *)" |
1248 | .IX Item "ev_periodic_again (loop, ev_periodic *)" |
1094 | Simply stops and restarts the periodic watcher again. This is only useful |
1249 | Simply stops and restarts the periodic watcher again. This is only useful |
1095 | when you changed some parameters or the reschedule callback would return |
1250 | when you changed some parameters or the reschedule callback would return |
1096 | a different time than the last time it was called (e.g. in a crond like |
1251 | a different time than the last time it was called (e.g. in a crond like |
1097 | program when the crontabs have changed). |
1252 | program when the crontabs have changed). |
|
|
1253 | .IP "ev_tstamp interval [read\-write]" 4 |
|
|
1254 | .IX Item "ev_tstamp interval [read-write]" |
|
|
1255 | The current interval value. Can be modified any time, but changes only |
|
|
1256 | take effect when the periodic timer fires or \f(CW\*(C`ev_periodic_again\*(C'\fR is being |
|
|
1257 | called. |
|
|
1258 | .IP "ev_tstamp (*reschedule_cb)(struct ev_periodic *w, ev_tstamp now) [read\-write]" 4 |
|
|
1259 | .IX Item "ev_tstamp (*reschedule_cb)(struct ev_periodic *w, ev_tstamp now) [read-write]" |
|
|
1260 | The current reschedule callback, or \f(CW0\fR, if this functionality is |
|
|
1261 | switched off. Can be changed any time, but changes only take effect when |
|
|
1262 | the periodic timer fires or \f(CW\*(C`ev_periodic_again\*(C'\fR is being called. |
1098 | .PP |
1263 | .PP |
1099 | Example: call a callback every hour, or, more precisely, whenever the |
1264 | Example: Call a callback every hour, or, more precisely, whenever the |
1100 | system clock is divisible by 3600. The callback invocation times have |
1265 | system clock is divisible by 3600. The callback invocation times have |
1101 | potentially a lot of jittering, but good long-term stability. |
1266 | potentially a lot of jittering, but good long-term stability. |
1102 | .PP |
1267 | .PP |
1103 | .Vb 5 |
1268 | .Vb 5 |
1104 | \& static void |
1269 | \& static void |
… | |
… | |
1112 | \& struct ev_periodic hourly_tick; |
1277 | \& struct ev_periodic hourly_tick; |
1113 | \& ev_periodic_init (&hourly_tick, clock_cb, 0., 3600., 0); |
1278 | \& ev_periodic_init (&hourly_tick, clock_cb, 0., 3600., 0); |
1114 | \& ev_periodic_start (loop, &hourly_tick); |
1279 | \& ev_periodic_start (loop, &hourly_tick); |
1115 | .Ve |
1280 | .Ve |
1116 | .PP |
1281 | .PP |
1117 | Example: the same as above, but use a reschedule callback to do it: |
1282 | Example: The same as above, but use a reschedule callback to do it: |
1118 | .PP |
1283 | .PP |
1119 | .Vb 1 |
1284 | .Vb 1 |
1120 | \& #include <math.h> |
1285 | \& #include <math.h> |
1121 | .Ve |
1286 | .Ve |
1122 | .PP |
1287 | .PP |
… | |
… | |
1130 | .PP |
1295 | .PP |
1131 | .Vb 1 |
1296 | .Vb 1 |
1132 | \& ev_periodic_init (&hourly_tick, clock_cb, 0., 0., my_scheduler_cb); |
1297 | \& ev_periodic_init (&hourly_tick, clock_cb, 0., 0., my_scheduler_cb); |
1133 | .Ve |
1298 | .Ve |
1134 | .PP |
1299 | .PP |
1135 | Example: call a callback every hour, starting now: |
1300 | Example: Call a callback every hour, starting now: |
1136 | .PP |
1301 | .PP |
1137 | .Vb 4 |
1302 | .Vb 4 |
1138 | \& struct ev_periodic hourly_tick; |
1303 | \& struct ev_periodic hourly_tick; |
1139 | \& ev_periodic_init (&hourly_tick, clock_cb, |
1304 | \& ev_periodic_init (&hourly_tick, clock_cb, |
1140 | \& fmod (ev_now (loop), 3600.), 3600., 0); |
1305 | \& fmod (ev_now (loop), 3600.), 3600., 0); |
… | |
… | |
1160 | .IP "ev_signal_set (ev_signal *, int signum)" 4 |
1325 | .IP "ev_signal_set (ev_signal *, int signum)" 4 |
1161 | .IX Item "ev_signal_set (ev_signal *, int signum)" |
1326 | .IX Item "ev_signal_set (ev_signal *, int signum)" |
1162 | .PD |
1327 | .PD |
1163 | Configures the watcher to trigger on the given signal number (usually one |
1328 | Configures the watcher to trigger on the given signal number (usually one |
1164 | of the \f(CW\*(C`SIGxxx\*(C'\fR constants). |
1329 | of the \f(CW\*(C`SIGxxx\*(C'\fR constants). |
|
|
1330 | .IP "int signum [read\-only]" 4 |
|
|
1331 | .IX Item "int signum [read-only]" |
|
|
1332 | The signal the watcher watches out for. |
1165 | .ie n .Sh """ev_child"" \- watch out for process status changes" |
1333 | .ie n .Sh """ev_child"" \- watch out for process status changes" |
1166 | .el .Sh "\f(CWev_child\fP \- watch out for process status changes" |
1334 | .el .Sh "\f(CWev_child\fP \- watch out for process status changes" |
1167 | .IX Subsection "ev_child - watch out for process status changes" |
1335 | .IX Subsection "ev_child - watch out for process status changes" |
1168 | Child watchers trigger when your process receives a \s-1SIGCHLD\s0 in response to |
1336 | Child watchers trigger when your process receives a \s-1SIGCHLD\s0 in response to |
1169 | some child status changes (most typically when a child of yours dies). |
1337 | some child status changes (most typically when a child of yours dies). |
… | |
… | |
1177 | \&\fIany\fR process if \f(CW\*(C`pid\*(C'\fR is specified as \f(CW0\fR). The callback can look |
1345 | \&\fIany\fR process if \f(CW\*(C`pid\*(C'\fR is specified as \f(CW0\fR). The callback can look |
1178 | at the \f(CW\*(C`rstatus\*(C'\fR member of the \f(CW\*(C`ev_child\*(C'\fR watcher structure to see |
1346 | at the \f(CW\*(C`rstatus\*(C'\fR member of the \f(CW\*(C`ev_child\*(C'\fR watcher structure to see |
1179 | the status word (use the macros from \f(CW\*(C`sys/wait.h\*(C'\fR and see your systems |
1347 | the status word (use the macros from \f(CW\*(C`sys/wait.h\*(C'\fR and see your systems |
1180 | \&\f(CW\*(C`waitpid\*(C'\fR documentation). The \f(CW\*(C`rpid\*(C'\fR member contains the pid of the |
1348 | \&\f(CW\*(C`waitpid\*(C'\fR documentation). The \f(CW\*(C`rpid\*(C'\fR member contains the pid of the |
1181 | process causing the status change. |
1349 | process causing the status change. |
|
|
1350 | .IP "int pid [read\-only]" 4 |
|
|
1351 | .IX Item "int pid [read-only]" |
|
|
1352 | The process id this watcher watches out for, or \f(CW0\fR, meaning any process id. |
|
|
1353 | .IP "int rpid [read\-write]" 4 |
|
|
1354 | .IX Item "int rpid [read-write]" |
|
|
1355 | The process id that detected a status change. |
|
|
1356 | .IP "int rstatus [read\-write]" 4 |
|
|
1357 | .IX Item "int rstatus [read-write]" |
|
|
1358 | The process exit/trace status caused by \f(CW\*(C`rpid\*(C'\fR (see your systems |
|
|
1359 | \&\f(CW\*(C`waitpid\*(C'\fR and \f(CW\*(C`sys/wait.h\*(C'\fR documentation for details). |
1182 | .PP |
1360 | .PP |
1183 | Example: try to exit cleanly on \s-1SIGINT\s0 and \s-1SIGTERM\s0. |
1361 | Example: Try to exit cleanly on \s-1SIGINT\s0 and \s-1SIGTERM\s0. |
1184 | .PP |
1362 | .PP |
1185 | .Vb 5 |
1363 | .Vb 5 |
1186 | \& static void |
1364 | \& static void |
1187 | \& sigint_cb (struct ev_loop *loop, struct ev_signal *w, int revents) |
1365 | \& sigint_cb (struct ev_loop *loop, struct ev_signal *w, int revents) |
1188 | \& { |
1366 | \& { |
… | |
… | |
1192 | .PP |
1370 | .PP |
1193 | .Vb 3 |
1371 | .Vb 3 |
1194 | \& struct ev_signal signal_watcher; |
1372 | \& struct ev_signal signal_watcher; |
1195 | \& ev_signal_init (&signal_watcher, sigint_cb, SIGINT); |
1373 | \& ev_signal_init (&signal_watcher, sigint_cb, SIGINT); |
1196 | \& ev_signal_start (loop, &sigint_cb); |
1374 | \& ev_signal_start (loop, &sigint_cb); |
|
|
1375 | .Ve |
|
|
1376 | .ie n .Sh """ev_stat"" \- did the file attributes just change?" |
|
|
1377 | .el .Sh "\f(CWev_stat\fP \- did the file attributes just change?" |
|
|
1378 | .IX Subsection "ev_stat - did the file attributes just change?" |
|
|
1379 | This watches a filesystem path for attribute changes. That is, it calls |
|
|
1380 | \&\f(CW\*(C`stat\*(C'\fR regularly (or when the \s-1OS\s0 says it changed) and sees if it changed |
|
|
1381 | compared to the last time, invoking the callback if it did. |
|
|
1382 | .PP |
|
|
1383 | The path does not need to exist: changing from \*(L"path exists\*(R" to \*(L"path does |
|
|
1384 | not exist\*(R" is a status change like any other. The condition \*(L"path does |
|
|
1385 | not exist\*(R" is signified by the \f(CW\*(C`st_nlink\*(C'\fR field being zero (which is |
|
|
1386 | otherwise always forced to be at least one) and all the other fields of |
|
|
1387 | the stat buffer having unspecified contents. |
|
|
1388 | .PP |
|
|
1389 | The path \fIshould\fR be absolute and \fImust not\fR end in a slash. If it is |
|
|
1390 | relative and your working directory changes, the behaviour is undefined. |
|
|
1391 | .PP |
|
|
1392 | Since there is no standard to do this, the portable implementation simply |
|
|
1393 | calls \f(CW\*(C`stat (2)\*(C'\fR regularly on the path to see if it changed somehow. You |
|
|
1394 | can specify a recommended polling interval for this case. If you specify |
|
|
1395 | a polling interval of \f(CW0\fR (highly recommended!) then a \fIsuitable, |
|
|
1396 | unspecified default\fR value will be used (which you can expect to be around |
|
|
1397 | five seconds, although this might change dynamically). Libev will also |
|
|
1398 | impose a minimum interval which is currently around \f(CW0.1\fR, but thats |
|
|
1399 | usually overkill. |
|
|
1400 | .PP |
|
|
1401 | This watcher type is not meant for massive numbers of stat watchers, |
|
|
1402 | as even with OS-supported change notifications, this can be |
|
|
1403 | resource\-intensive. |
|
|
1404 | .PP |
|
|
1405 | At the time of this writing, only the Linux inotify interface is |
|
|
1406 | implemented (implementing kqueue support is left as an exercise for the |
|
|
1407 | reader). Inotify will be used to give hints only and should not change the |
|
|
1408 | semantics of \f(CW\*(C`ev_stat\*(C'\fR watchers, which means that libev sometimes needs |
|
|
1409 | to fall back to regular polling again even with inotify, but changes are |
|
|
1410 | usually detected immediately, and if the file exists there will be no |
|
|
1411 | polling. |
|
|
1412 | .IP "ev_stat_init (ev_stat *, callback, const char *path, ev_tstamp interval)" 4 |
|
|
1413 | .IX Item "ev_stat_init (ev_stat *, callback, const char *path, ev_tstamp interval)" |
|
|
1414 | .PD 0 |
|
|
1415 | .IP "ev_stat_set (ev_stat *, const char *path, ev_tstamp interval)" 4 |
|
|
1416 | .IX Item "ev_stat_set (ev_stat *, const char *path, ev_tstamp interval)" |
|
|
1417 | .PD |
|
|
1418 | Configures the watcher to wait for status changes of the given |
|
|
1419 | \&\f(CW\*(C`path\*(C'\fR. The \f(CW\*(C`interval\*(C'\fR is a hint on how quickly a change is expected to |
|
|
1420 | be detected and should normally be specified as \f(CW0\fR to let libev choose |
|
|
1421 | a suitable value. The memory pointed to by \f(CW\*(C`path\*(C'\fR must point to the same |
|
|
1422 | path for as long as the watcher is active. |
|
|
1423 | .Sp |
|
|
1424 | The callback will be receive \f(CW\*(C`EV_STAT\*(C'\fR when a change was detected, |
|
|
1425 | relative to the attributes at the time the watcher was started (or the |
|
|
1426 | last change was detected). |
|
|
1427 | .IP "ev_stat_stat (ev_stat *)" 4 |
|
|
1428 | .IX Item "ev_stat_stat (ev_stat *)" |
|
|
1429 | Updates the stat buffer immediately with new values. If you change the |
|
|
1430 | watched path in your callback, you could call this fucntion to avoid |
|
|
1431 | detecting this change (while introducing a race condition). Can also be |
|
|
1432 | useful simply to find out the new values. |
|
|
1433 | .IP "ev_statdata attr [read\-only]" 4 |
|
|
1434 | .IX Item "ev_statdata attr [read-only]" |
|
|
1435 | The most-recently detected attributes of the file. Although the type is of |
|
|
1436 | \&\f(CW\*(C`ev_statdata\*(C'\fR, this is usually the (or one of the) \f(CW\*(C`struct stat\*(C'\fR types |
|
|
1437 | suitable for your system. If the \f(CW\*(C`st_nlink\*(C'\fR member is \f(CW0\fR, then there |
|
|
1438 | was some error while \f(CW\*(C`stat\*(C'\fRing the file. |
|
|
1439 | .IP "ev_statdata prev [read\-only]" 4 |
|
|
1440 | .IX Item "ev_statdata prev [read-only]" |
|
|
1441 | The previous attributes of the file. The callback gets invoked whenever |
|
|
1442 | \&\f(CW\*(C`prev\*(C'\fR != \f(CW\*(C`attr\*(C'\fR. |
|
|
1443 | .IP "ev_tstamp interval [read\-only]" 4 |
|
|
1444 | .IX Item "ev_tstamp interval [read-only]" |
|
|
1445 | The specified interval. |
|
|
1446 | .IP "const char *path [read\-only]" 4 |
|
|
1447 | .IX Item "const char *path [read-only]" |
|
|
1448 | The filesystem path that is being watched. |
|
|
1449 | .PP |
|
|
1450 | Example: Watch \f(CW\*(C`/etc/passwd\*(C'\fR for attribute changes. |
|
|
1451 | .PP |
|
|
1452 | .Vb 15 |
|
|
1453 | \& static void |
|
|
1454 | \& passwd_cb (struct ev_loop *loop, ev_stat *w, int revents) |
|
|
1455 | \& { |
|
|
1456 | \& /* /etc/passwd changed in some way */ |
|
|
1457 | \& if (w->attr.st_nlink) |
|
|
1458 | \& { |
|
|
1459 | \& printf ("passwd current size %ld\en", (long)w->attr.st_size); |
|
|
1460 | \& printf ("passwd current atime %ld\en", (long)w->attr.st_mtime); |
|
|
1461 | \& printf ("passwd current mtime %ld\en", (long)w->attr.st_mtime); |
|
|
1462 | \& } |
|
|
1463 | \& else |
|
|
1464 | \& /* you shalt not abuse printf for puts */ |
|
|
1465 | \& puts ("wow, /etc/passwd is not there, expect problems. " |
|
|
1466 | \& "if this is windows, they already arrived\en"); |
|
|
1467 | \& } |
|
|
1468 | .Ve |
|
|
1469 | .PP |
|
|
1470 | .Vb 2 |
|
|
1471 | \& ... |
|
|
1472 | \& ev_stat passwd; |
|
|
1473 | .Ve |
|
|
1474 | .PP |
|
|
1475 | .Vb 2 |
|
|
1476 | \& ev_stat_init (&passwd, passwd_cb, "/etc/passwd"); |
|
|
1477 | \& ev_stat_start (loop, &passwd); |
1197 | .Ve |
1478 | .Ve |
1198 | .ie n .Sh """ev_idle"" \- when you've got nothing better to do..." |
1479 | .ie n .Sh """ev_idle"" \- when you've got nothing better to do..." |
1199 | .el .Sh "\f(CWev_idle\fP \- when you've got nothing better to do..." |
1480 | .el .Sh "\f(CWev_idle\fP \- when you've got nothing better to do..." |
1200 | .IX Subsection "ev_idle - when you've got nothing better to do..." |
1481 | .IX Subsection "ev_idle - when you've got nothing better to do..." |
1201 | Idle watchers trigger events when there are no other events are pending |
1482 | Idle watchers trigger events when there are no other events are pending |
… | |
… | |
1217 | .IX Item "ev_idle_init (ev_signal *, callback)" |
1498 | .IX Item "ev_idle_init (ev_signal *, callback)" |
1218 | Initialises and configures the idle watcher \- it has no parameters of any |
1499 | Initialises and configures the idle watcher \- it has no parameters of any |
1219 | kind. There is a \f(CW\*(C`ev_idle_set\*(C'\fR macro, but using it is utterly pointless, |
1500 | kind. There is a \f(CW\*(C`ev_idle_set\*(C'\fR macro, but using it is utterly pointless, |
1220 | believe me. |
1501 | believe me. |
1221 | .PP |
1502 | .PP |
1222 | Example: dynamically allocate an \f(CW\*(C`ev_idle\*(C'\fR, start it, and in the |
1503 | Example: Dynamically allocate an \f(CW\*(C`ev_idle\*(C'\fR watcher, start it, and in the |
1223 | callback, free it. Alos, use no error checking, as usual. |
1504 | callback, free it. Also, use no error checking, as usual. |
1224 | .PP |
1505 | .PP |
1225 | .Vb 7 |
1506 | .Vb 7 |
1226 | \& static void |
1507 | \& static void |
1227 | \& idle_cb (struct ev_loop *loop, struct ev_idle *w, int revents) |
1508 | \& idle_cb (struct ev_loop *loop, struct ev_idle *w, int revents) |
1228 | \& { |
1509 | \& { |
… | |
… | |
1242 | .IX Subsection "ev_prepare and ev_check - customise your event loop!" |
1523 | .IX Subsection "ev_prepare and ev_check - customise your event loop!" |
1243 | Prepare and check watchers are usually (but not always) used in tandem: |
1524 | Prepare and check watchers are usually (but not always) used in tandem: |
1244 | prepare watchers get invoked before the process blocks and check watchers |
1525 | prepare watchers get invoked before the process blocks and check watchers |
1245 | afterwards. |
1526 | afterwards. |
1246 | .PP |
1527 | .PP |
|
|
1528 | You \fImust not\fR call \f(CW\*(C`ev_loop\*(C'\fR or similar functions that enter |
|
|
1529 | the current event loop from either \f(CW\*(C`ev_prepare\*(C'\fR or \f(CW\*(C`ev_check\*(C'\fR |
|
|
1530 | watchers. Other loops than the current one are fine, however. The |
|
|
1531 | rationale behind this is that you do not need to check for recursion in |
|
|
1532 | those watchers, i.e. the sequence will always be \f(CW\*(C`ev_prepare\*(C'\fR, blocking, |
|
|
1533 | \&\f(CW\*(C`ev_check\*(C'\fR so if you have one watcher of each kind they will always be |
|
|
1534 | called in pairs bracketing the blocking call. |
|
|
1535 | .PP |
1247 | Their main purpose is to integrate other event mechanisms into libev and |
1536 | Their main purpose is to integrate other event mechanisms into libev and |
1248 | their use is somewhat advanced. This could be used, for example, to track |
1537 | their use is somewhat advanced. This could be used, for example, to track |
1249 | variable changes, implement your own watchers, integrate net-snmp or a |
1538 | variable changes, implement your own watchers, integrate net-snmp or a |
1250 | coroutine library and lots more. |
1539 | coroutine library and lots more. They are also occasionally useful if |
|
|
1540 | you cache some data and want to flush it before blocking (for example, |
|
|
1541 | in X programs you might want to do an \f(CW\*(C`XFlush ()\*(C'\fR in an \f(CW\*(C`ev_prepare\*(C'\fR |
|
|
1542 | watcher). |
1251 | .PP |
1543 | .PP |
1252 | This is done by examining in each prepare call which file descriptors need |
1544 | This is done by examining in each prepare call which file descriptors need |
1253 | to be watched by the other library, registering \f(CW\*(C`ev_io\*(C'\fR watchers for |
1545 | to be watched by the other library, registering \f(CW\*(C`ev_io\*(C'\fR watchers for |
1254 | them and starting an \f(CW\*(C`ev_timer\*(C'\fR watcher for any timeouts (many libraries |
1546 | them and starting an \f(CW\*(C`ev_timer\*(C'\fR watcher for any timeouts (many libraries |
1255 | provide just this functionality). Then, in the check watcher you check for |
1547 | provide just this functionality). Then, in the check watcher you check for |
… | |
… | |
1274 | .PD |
1566 | .PD |
1275 | Initialises and configures the prepare or check watcher \- they have no |
1567 | Initialises and configures the prepare or check watcher \- they have no |
1276 | parameters of any kind. There are \f(CW\*(C`ev_prepare_set\*(C'\fR and \f(CW\*(C`ev_check_set\*(C'\fR |
1568 | parameters of any kind. There are \f(CW\*(C`ev_prepare_set\*(C'\fR and \f(CW\*(C`ev_check_set\*(C'\fR |
1277 | macros, but using them is utterly, utterly and completely pointless. |
1569 | macros, but using them is utterly, utterly and completely pointless. |
1278 | .PP |
1570 | .PP |
1279 | Example: *TODO*. |
1571 | Example: To include a library such as adns, you would add \s-1IO\s0 watchers |
|
|
1572 | and a timeout watcher in a prepare handler, as required by libadns, and |
|
|
1573 | in a check watcher, destroy them and call into libadns. What follows is |
|
|
1574 | pseudo-code only of course: |
|
|
1575 | .PP |
|
|
1576 | .Vb 2 |
|
|
1577 | \& static ev_io iow [nfd]; |
|
|
1578 | \& static ev_timer tw; |
|
|
1579 | .Ve |
|
|
1580 | .PP |
|
|
1581 | .Vb 9 |
|
|
1582 | \& static void |
|
|
1583 | \& io_cb (ev_loop *loop, ev_io *w, int revents) |
|
|
1584 | \& { |
|
|
1585 | \& // set the relevant poll flags |
|
|
1586 | \& // could also call adns_processreadable etc. here |
|
|
1587 | \& struct pollfd *fd = (struct pollfd *)w->data; |
|
|
1588 | \& if (revents & EV_READ ) fd->revents |= fd->events & POLLIN; |
|
|
1589 | \& if (revents & EV_WRITE) fd->revents |= fd->events & POLLOUT; |
|
|
1590 | \& } |
|
|
1591 | .Ve |
|
|
1592 | .PP |
|
|
1593 | .Vb 7 |
|
|
1594 | \& // create io watchers for each fd and a timer before blocking |
|
|
1595 | \& static void |
|
|
1596 | \& adns_prepare_cb (ev_loop *loop, ev_prepare *w, int revents) |
|
|
1597 | \& { |
|
|
1598 | \& int timeout = 3600000;truct pollfd fds [nfd]; |
|
|
1599 | \& // actual code will need to loop here and realloc etc. |
|
|
1600 | \& adns_beforepoll (ads, fds, &nfd, &timeout, timeval_from (ev_time ())); |
|
|
1601 | .Ve |
|
|
1602 | .PP |
|
|
1603 | .Vb 3 |
|
|
1604 | \& /* the callback is illegal, but won't be called as we stop during check */ |
|
|
1605 | \& ev_timer_init (&tw, 0, timeout * 1e-3); |
|
|
1606 | \& ev_timer_start (loop, &tw); |
|
|
1607 | .Ve |
|
|
1608 | .PP |
|
|
1609 | .Vb 6 |
|
|
1610 | \& // create on ev_io per pollfd |
|
|
1611 | \& for (int i = 0; i < nfd; ++i) |
|
|
1612 | \& { |
|
|
1613 | \& ev_io_init (iow + i, io_cb, fds [i].fd, |
|
|
1614 | \& ((fds [i].events & POLLIN ? EV_READ : 0) |
|
|
1615 | \& | (fds [i].events & POLLOUT ? EV_WRITE : 0))); |
|
|
1616 | .Ve |
|
|
1617 | .PP |
|
|
1618 | .Vb 5 |
|
|
1619 | \& fds [i].revents = 0; |
|
|
1620 | \& iow [i].data = fds + i; |
|
|
1621 | \& ev_io_start (loop, iow + i); |
|
|
1622 | \& } |
|
|
1623 | \& } |
|
|
1624 | .Ve |
|
|
1625 | .PP |
|
|
1626 | .Vb 5 |
|
|
1627 | \& // stop all watchers after blocking |
|
|
1628 | \& static void |
|
|
1629 | \& adns_check_cb (ev_loop *loop, ev_check *w, int revents) |
|
|
1630 | \& { |
|
|
1631 | \& ev_timer_stop (loop, &tw); |
|
|
1632 | .Ve |
|
|
1633 | .PP |
|
|
1634 | .Vb 2 |
|
|
1635 | \& for (int i = 0; i < nfd; ++i) |
|
|
1636 | \& ev_io_stop (loop, iow + i); |
|
|
1637 | .Ve |
|
|
1638 | .PP |
|
|
1639 | .Vb 2 |
|
|
1640 | \& adns_afterpoll (adns, fds, nfd, timeval_from (ev_now (loop)); |
|
|
1641 | \& } |
|
|
1642 | .Ve |
1280 | .ie n .Sh """ev_embed"" \- when one backend isn't enough..." |
1643 | .ie n .Sh """ev_embed"" \- when one backend isn't enough..." |
1281 | .el .Sh "\f(CWev_embed\fP \- when one backend isn't enough..." |
1644 | .el .Sh "\f(CWev_embed\fP \- when one backend isn't enough..." |
1282 | .IX Subsection "ev_embed - when one backend isn't enough..." |
1645 | .IX Subsection "ev_embed - when one backend isn't enough..." |
1283 | This is a rather advanced watcher type that lets you embed one event loop |
1646 | This is a rather advanced watcher type that lets you embed one event loop |
1284 | into another (currently only \f(CW\*(C`ev_io\*(C'\fR events are supported in the embedded |
1647 | into another (currently only \f(CW\*(C`ev_io\*(C'\fR events are supported in the embedded |
… | |
… | |
1367 | .IP "ev_embed_sweep (loop, ev_embed *)" 4 |
1730 | .IP "ev_embed_sweep (loop, ev_embed *)" 4 |
1368 | .IX Item "ev_embed_sweep (loop, ev_embed *)" |
1731 | .IX Item "ev_embed_sweep (loop, ev_embed *)" |
1369 | Make a single, non-blocking sweep over the embedded loop. This works |
1732 | Make a single, non-blocking sweep over the embedded loop. This works |
1370 | similarly to \f(CW\*(C`ev_loop (embedded_loop, EVLOOP_NONBLOCK)\*(C'\fR, but in the most |
1733 | similarly to \f(CW\*(C`ev_loop (embedded_loop, EVLOOP_NONBLOCK)\*(C'\fR, but in the most |
1371 | apropriate way for embedded loops. |
1734 | apropriate way for embedded loops. |
|
|
1735 | .IP "struct ev_loop *loop [read\-only]" 4 |
|
|
1736 | .IX Item "struct ev_loop *loop [read-only]" |
|
|
1737 | The embedded event loop. |
|
|
1738 | .ie n .Sh """ev_fork"" \- the audacity to resume the event loop after a fork" |
|
|
1739 | .el .Sh "\f(CWev_fork\fP \- the audacity to resume the event loop after a fork" |
|
|
1740 | .IX Subsection "ev_fork - the audacity to resume the event loop after a fork" |
|
|
1741 | Fork watchers are called when a \f(CW\*(C`fork ()\*(C'\fR was detected (usually because |
|
|
1742 | whoever is a good citizen cared to tell libev about it by calling |
|
|
1743 | \&\f(CW\*(C`ev_default_fork\*(C'\fR or \f(CW\*(C`ev_loop_fork\*(C'\fR). The invocation is done before the |
|
|
1744 | event loop blocks next and before \f(CW\*(C`ev_check\*(C'\fR watchers are being called, |
|
|
1745 | and only in the child after the fork. If whoever good citizen calling |
|
|
1746 | \&\f(CW\*(C`ev_default_fork\*(C'\fR cheats and calls it in the wrong process, the fork |
|
|
1747 | handlers will be invoked, too, of course. |
|
|
1748 | .IP "ev_fork_init (ev_signal *, callback)" 4 |
|
|
1749 | .IX Item "ev_fork_init (ev_signal *, callback)" |
|
|
1750 | Initialises and configures the fork watcher \- it has no parameters of any |
|
|
1751 | kind. There is a \f(CW\*(C`ev_fork_set\*(C'\fR macro, but using it is utterly pointless, |
|
|
1752 | believe me. |
1372 | .SH "OTHER FUNCTIONS" |
1753 | .SH "OTHER FUNCTIONS" |
1373 | .IX Header "OTHER FUNCTIONS" |
1754 | .IX Header "OTHER FUNCTIONS" |
1374 | There are some other functions of possible interest. Described. Here. Now. |
1755 | There are some other functions of possible interest. Described. Here. Now. |
1375 | .IP "ev_once (loop, int fd, int events, ev_tstamp timeout, callback)" 4 |
1756 | .IP "ev_once (loop, int fd, int events, ev_tstamp timeout, callback)" 4 |
1376 | .IX Item "ev_once (loop, int fd, int events, ev_tstamp timeout, callback)" |
1757 | .IX Item "ev_once (loop, int fd, int events, ev_tstamp timeout, callback)" |
… | |
… | |
1515 | \&\f(CW\*(C`ev_TYPE_again\*(C'\fR function. |
1896 | \&\f(CW\*(C`ev_TYPE_again\*(C'\fR function. |
1516 | .ie n .IP "w\->sweep () ""ev::embed"" only" 4 |
1897 | .ie n .IP "w\->sweep () ""ev::embed"" only" 4 |
1517 | .el .IP "w\->sweep () \f(CWev::embed\fR only" 4 |
1898 | .el .IP "w\->sweep () \f(CWev::embed\fR only" 4 |
1518 | .IX Item "w->sweep () ev::embed only" |
1899 | .IX Item "w->sweep () ev::embed only" |
1519 | Invokes \f(CW\*(C`ev_embed_sweep\*(C'\fR. |
1900 | Invokes \f(CW\*(C`ev_embed_sweep\*(C'\fR. |
|
|
1901 | .ie n .IP "w\->update () ""ev::stat"" only" 4 |
|
|
1902 | .el .IP "w\->update () \f(CWev::stat\fR only" 4 |
|
|
1903 | .IX Item "w->update () ev::stat only" |
|
|
1904 | Invokes \f(CW\*(C`ev_stat_stat\*(C'\fR. |
1520 | .RE |
1905 | .RE |
1521 | .RS 4 |
1906 | .RS 4 |
1522 | .RE |
1907 | .RE |
1523 | .PP |
1908 | .PP |
1524 | Example: Define a class with an \s-1IO\s0 and idle watcher, start one of them in |
1909 | Example: Define a class with an \s-1IO\s0 and idle watcher, start one of them in |
… | |
… | |
1541 | \& : io (this, &myclass::io_cb), |
1926 | \& : io (this, &myclass::io_cb), |
1542 | \& idle (this, &myclass::idle_cb) |
1927 | \& idle (this, &myclass::idle_cb) |
1543 | \& { |
1928 | \& { |
1544 | \& io.start (fd, ev::READ); |
1929 | \& io.start (fd, ev::READ); |
1545 | \& } |
1930 | \& } |
|
|
1931 | .Ve |
|
|
1932 | .SH "MACRO MAGIC" |
|
|
1933 | .IX Header "MACRO MAGIC" |
|
|
1934 | Libev can be compiled with a variety of options, the most fundemantal is |
|
|
1935 | \&\f(CW\*(C`EV_MULTIPLICITY\*(C'\fR. This option determines wether (most) functions and |
|
|
1936 | callbacks have an initial \f(CW\*(C`struct ev_loop *\*(C'\fR argument. |
|
|
1937 | .PP |
|
|
1938 | To make it easier to write programs that cope with either variant, the |
|
|
1939 | following macros are defined: |
|
|
1940 | .ie n .IP """EV_A""\fR, \f(CW""EV_A_""" 4 |
|
|
1941 | .el .IP "\f(CWEV_A\fR, \f(CWEV_A_\fR" 4 |
|
|
1942 | .IX Item "EV_A, EV_A_" |
|
|
1943 | This provides the loop \fIargument\fR for functions, if one is required (\*(L"ev |
|
|
1944 | loop argument\*(R"). The \f(CW\*(C`EV_A\*(C'\fR form is used when this is the sole argument, |
|
|
1945 | \&\f(CW\*(C`EV_A_\*(C'\fR is used when other arguments are following. Example: |
|
|
1946 | .Sp |
|
|
1947 | .Vb 3 |
|
|
1948 | \& ev_unref (EV_A); |
|
|
1949 | \& ev_timer_add (EV_A_ watcher); |
|
|
1950 | \& ev_loop (EV_A_ 0); |
|
|
1951 | .Ve |
|
|
1952 | .Sp |
|
|
1953 | It assumes the variable \f(CW\*(C`loop\*(C'\fR of type \f(CW\*(C`struct ev_loop *\*(C'\fR is in scope, |
|
|
1954 | which is often provided by the following macro. |
|
|
1955 | .ie n .IP """EV_P""\fR, \f(CW""EV_P_""" 4 |
|
|
1956 | .el .IP "\f(CWEV_P\fR, \f(CWEV_P_\fR" 4 |
|
|
1957 | .IX Item "EV_P, EV_P_" |
|
|
1958 | This provides the loop \fIparameter\fR for functions, if one is required (\*(L"ev |
|
|
1959 | loop parameter\*(R"). The \f(CW\*(C`EV_P\*(C'\fR form is used when this is the sole parameter, |
|
|
1960 | \&\f(CW\*(C`EV_P_\*(C'\fR is used when other parameters are following. Example: |
|
|
1961 | .Sp |
|
|
1962 | .Vb 2 |
|
|
1963 | \& // this is how ev_unref is being declared |
|
|
1964 | \& static void ev_unref (EV_P); |
|
|
1965 | .Ve |
|
|
1966 | .Sp |
|
|
1967 | .Vb 2 |
|
|
1968 | \& // this is how you can declare your typical callback |
|
|
1969 | \& static void cb (EV_P_ ev_timer *w, int revents) |
|
|
1970 | .Ve |
|
|
1971 | .Sp |
|
|
1972 | It declares a parameter \f(CW\*(C`loop\*(C'\fR of type \f(CW\*(C`struct ev_loop *\*(C'\fR, quite |
|
|
1973 | suitable for use with \f(CW\*(C`EV_A\*(C'\fR. |
|
|
1974 | .ie n .IP """EV_DEFAULT""\fR, \f(CW""EV_DEFAULT_""" 4 |
|
|
1975 | .el .IP "\f(CWEV_DEFAULT\fR, \f(CWEV_DEFAULT_\fR" 4 |
|
|
1976 | .IX Item "EV_DEFAULT, EV_DEFAULT_" |
|
|
1977 | Similar to the other two macros, this gives you the value of the default |
|
|
1978 | loop, if multiple loops are supported (\*(L"ev loop default\*(R"). |
|
|
1979 | .PP |
|
|
1980 | Example: Declare and initialise a check watcher, working regardless of |
|
|
1981 | wether multiple loops are supported or not. |
|
|
1982 | .PP |
|
|
1983 | .Vb 5 |
|
|
1984 | \& static void |
|
|
1985 | \& check_cb (EV_P_ ev_timer *w, int revents) |
|
|
1986 | \& { |
|
|
1987 | \& ev_check_stop (EV_A_ w); |
|
|
1988 | \& } |
|
|
1989 | .Ve |
|
|
1990 | .PP |
|
|
1991 | .Vb 4 |
|
|
1992 | \& ev_check check; |
|
|
1993 | \& ev_check_init (&check, check_cb); |
|
|
1994 | \& ev_check_start (EV_DEFAULT_ &check); |
|
|
1995 | \& ev_loop (EV_DEFAULT_ 0); |
1546 | .Ve |
1996 | .Ve |
1547 | .SH "EMBEDDING" |
1997 | .SH "EMBEDDING" |
1548 | .IX Header "EMBEDDING" |
1998 | .IX Header "EMBEDDING" |
1549 | Libev can (and often is) directly embedded into host |
1999 | Libev can (and often is) directly embedded into host |
1550 | applications. Examples of applications that embed it include the Deliantra |
2000 | applications. Examples of applications that embed it include the Deliantra |
… | |
… | |
1730 | otherwise another method will be used as fallback. This is the preferred |
2180 | otherwise another method will be used as fallback. This is the preferred |
1731 | backend for Solaris 10 systems. |
2181 | backend for Solaris 10 systems. |
1732 | .IP "\s-1EV_USE_DEVPOLL\s0" 4 |
2182 | .IP "\s-1EV_USE_DEVPOLL\s0" 4 |
1733 | .IX Item "EV_USE_DEVPOLL" |
2183 | .IX Item "EV_USE_DEVPOLL" |
1734 | reserved for future expansion, works like the \s-1USE\s0 symbols above. |
2184 | reserved for future expansion, works like the \s-1USE\s0 symbols above. |
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2185 | .IP "\s-1EV_USE_INOTIFY\s0" 4 |
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2186 | .IX Item "EV_USE_INOTIFY" |
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2187 | If defined to be \f(CW1\fR, libev will compile in support for the Linux inotify |
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2188 | interface to speed up \f(CW\*(C`ev_stat\*(C'\fR watchers. Its actual availability will |
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2189 | be detected at runtime. |
1735 | .IP "\s-1EV_H\s0" 4 |
2190 | .IP "\s-1EV_H\s0" 4 |
1736 | .IX Item "EV_H" |
2191 | .IX Item "EV_H" |
1737 | The name of the \fIev.h\fR header file used to include it. The default if |
2192 | The name of the \fIev.h\fR header file used to include it. The default if |
1738 | undefined is \f(CW\*(C`<ev.h>\*(C'\fR in \fIevent.h\fR and \f(CW"ev.h"\fR in \fIev.c\fR. This |
2193 | undefined is \f(CW\*(C`<ev.h>\*(C'\fR in \fIevent.h\fR and \f(CW"ev.h"\fR in \fIev.c\fR. This |
1739 | can be used to virtually rename the \fIev.h\fR header file in case of conflicts. |
2194 | can be used to virtually rename the \fIev.h\fR header file in case of conflicts. |
… | |
… | |
1757 | If undefined or defined to \f(CW1\fR, then all event-loop-specific functions |
2212 | If undefined or defined to \f(CW1\fR, then all event-loop-specific functions |
1758 | will have the \f(CW\*(C`struct ev_loop *\*(C'\fR as first argument, and you can create |
2213 | will have the \f(CW\*(C`struct ev_loop *\*(C'\fR as first argument, and you can create |
1759 | additional independent event loops. Otherwise there will be no support |
2214 | additional independent event loops. Otherwise there will be no support |
1760 | for multiple event loops and there is no first event loop pointer |
2215 | for multiple event loops and there is no first event loop pointer |
1761 | argument. Instead, all functions act on the single default loop. |
2216 | argument. Instead, all functions act on the single default loop. |
1762 | .IP "\s-1EV_PERIODICS\s0" 4 |
2217 | .IP "\s-1EV_PERIODIC_ENABLE\s0" 4 |
1763 | .IX Item "EV_PERIODICS" |
2218 | .IX Item "EV_PERIODIC_ENABLE" |
1764 | If undefined or defined to be \f(CW1\fR, then periodic timers are supported, |
2219 | If undefined or defined to be \f(CW1\fR, then periodic timers are supported. If |
1765 | otherwise not. This saves a few kb of code. |
2220 | defined to be \f(CW0\fR, then they are not. Disabling them saves a few kB of |
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2221 | code. |
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2222 | .IP "\s-1EV_EMBED_ENABLE\s0" 4 |
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2223 | .IX Item "EV_EMBED_ENABLE" |
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2224 | If undefined or defined to be \f(CW1\fR, then embed watchers are supported. If |
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2225 | defined to be \f(CW0\fR, then they are not. |
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2226 | .IP "\s-1EV_STAT_ENABLE\s0" 4 |
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2227 | .IX Item "EV_STAT_ENABLE" |
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2228 | If undefined or defined to be \f(CW1\fR, then stat watchers are supported. If |
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2229 | defined to be \f(CW0\fR, then they are not. |
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2230 | .IP "\s-1EV_FORK_ENABLE\s0" 4 |
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2231 | .IX Item "EV_FORK_ENABLE" |
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2232 | If undefined or defined to be \f(CW1\fR, then fork watchers are supported. If |
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2233 | defined to be \f(CW0\fR, then they are not. |
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2234 | .IP "\s-1EV_MINIMAL\s0" 4 |
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2235 | .IX Item "EV_MINIMAL" |
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2236 | If you need to shave off some kilobytes of code at the expense of some |
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2237 | speed, define this symbol to \f(CW1\fR. Currently only used for gcc to override |
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2238 | some inlining decisions, saves roughly 30% codesize of amd64. |
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2239 | .IP "\s-1EV_PID_HASHSIZE\s0" 4 |
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2240 | .IX Item "EV_PID_HASHSIZE" |
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2241 | \&\f(CW\*(C`ev_child\*(C'\fR watchers use a small hash table to distribute workload by |
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2242 | pid. The default size is \f(CW16\fR (or \f(CW1\fR with \f(CW\*(C`EV_MINIMAL\*(C'\fR), usually more |
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2243 | than enough. If you need to manage thousands of children you might want to |
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2244 | increase this value (\fImust\fR be a power of two). |
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2245 | .IP "\s-1EV_INOTIFY_HASHSIZE\s0" 4 |
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2246 | .IX Item "EV_INOTIFY_HASHSIZE" |
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2247 | \&\f(CW\*(C`ev_staz\*(C'\fR watchers use a small hash table to distribute workload by |
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2248 | inotify watch id. The default size is \f(CW16\fR (or \f(CW1\fR with \f(CW\*(C`EV_MINIMAL\*(C'\fR), |
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2249 | usually more than enough. If you need to manage thousands of \f(CW\*(C`ev_stat\*(C'\fR |
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2250 | watchers you might want to increase this value (\fImust\fR be a power of |
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2251 | two). |
1766 | .IP "\s-1EV_COMMON\s0" 4 |
2252 | .IP "\s-1EV_COMMON\s0" 4 |
1767 | .IX Item "EV_COMMON" |
2253 | .IX Item "EV_COMMON" |
1768 | By default, all watchers have a \f(CW\*(C`void *data\*(C'\fR member. By redefining |
2254 | By default, all watchers have a \f(CW\*(C`void *data\*(C'\fR member. By redefining |
1769 | this macro to a something else you can include more and other types of |
2255 | this macro to a something else you can include more and other types of |
1770 | members. You have to define it each time you include one of the files, |
2256 | members. You have to define it each time you include one of the files, |
… | |
… | |
1775 | .Vb 3 |
2261 | .Vb 3 |
1776 | \& #define EV_COMMON \e |
2262 | \& #define EV_COMMON \e |
1777 | \& SV *self; /* contains this struct */ \e |
2263 | \& SV *self; /* contains this struct */ \e |
1778 | \& SV *cb_sv, *fh /* note no trailing ";" */ |
2264 | \& SV *cb_sv, *fh /* note no trailing ";" */ |
1779 | .Ve |
2265 | .Ve |
1780 | .IP "\s-1EV_CB_DECLARE\s0(type)" 4 |
2266 | .IP "\s-1EV_CB_DECLARE\s0 (type)" 4 |
1781 | .IX Item "EV_CB_DECLARE(type)" |
2267 | .IX Item "EV_CB_DECLARE (type)" |
1782 | .PD 0 |
2268 | .PD 0 |
1783 | .IP "\s-1EV_CB_INVOKE\s0(watcher,revents)" 4 |
2269 | .IP "\s-1EV_CB_INVOKE\s0 (watcher, revents)" 4 |
1784 | .IX Item "EV_CB_INVOKE(watcher,revents)" |
2270 | .IX Item "EV_CB_INVOKE (watcher, revents)" |
1785 | .IP "ev_set_cb(ev,cb)" 4 |
2271 | .IP "ev_set_cb (ev, cb)" 4 |
1786 | .IX Item "ev_set_cb(ev,cb)" |
2272 | .IX Item "ev_set_cb (ev, cb)" |
1787 | .PD |
2273 | .PD |
1788 | Can be used to change the callback member declaration in each watcher, |
2274 | Can be used to change the callback member declaration in each watcher, |
1789 | and the way callbacks are invoked and set. Must expand to a struct member |
2275 | and the way callbacks are invoked and set. Must expand to a struct member |
1790 | definition and a statement, respectively. See the \fIev.v\fR header file for |
2276 | definition and a statement, respectively. See the \fIev.v\fR header file for |
1791 | their default definitions. One possible use for overriding these is to |
2277 | their default definitions. One possible use for overriding these is to |
1792 | avoid the ev_loop pointer as first argument in all cases, or to use method |
2278 | avoid the \f(CW\*(C`struct ev_loop *\*(C'\fR as first argument in all cases, or to use |
1793 | calls instead of plain function calls in \*(C+. |
2279 | method calls instead of plain function calls in \*(C+. |
1794 | .Sh "\s-1EXAMPLES\s0" |
2280 | .Sh "\s-1EXAMPLES\s0" |
1795 | .IX Subsection "EXAMPLES" |
2281 | .IX Subsection "EXAMPLES" |
1796 | For a real-world example of a program the includes libev |
2282 | For a real-world example of a program the includes libev |
1797 | verbatim, you can have a look at the \s-1EV\s0 perl module |
2283 | verbatim, you can have a look at the \s-1EV\s0 perl module |
1798 | (<http://software.schmorp.de/pkg/EV.html>). It has the libev files in |
2284 | (<http://software.schmorp.de/pkg/EV.html>). It has the libev files in |
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… | |
1819 | .Sp |
2305 | .Sp |
1820 | .Vb 2 |
2306 | .Vb 2 |
1821 | \& #include "ev_cpp.h" |
2307 | \& #include "ev_cpp.h" |
1822 | \& #include "ev.c" |
2308 | \& #include "ev.c" |
1823 | .Ve |
2309 | .Ve |
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2310 | .SH "COMPLEXITIES" |
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2311 | .IX Header "COMPLEXITIES" |
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2312 | In this section the complexities of (many of) the algorithms used inside |
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2313 | libev will be explained. For complexity discussions about backends see the |
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2314 | documentation for \f(CW\*(C`ev_default_init\*(C'\fR. |
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2315 | .RS 4 |
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2316 | .IP "Starting and stopping timer/periodic watchers: O(log skipped_other_timers)" 4 |
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2317 | .IX Item "Starting and stopping timer/periodic watchers: O(log skipped_other_timers)" |
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2318 | .PD 0 |
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2319 | .IP "Changing timer/periodic watchers (by autorepeat, again): O(log skipped_other_timers)" 4 |
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2320 | .IX Item "Changing timer/periodic watchers (by autorepeat, again): O(log skipped_other_timers)" |
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2321 | .IP "Starting io/check/prepare/idle/signal/child watchers: O(1)" 4 |
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2322 | .IX Item "Starting io/check/prepare/idle/signal/child watchers: O(1)" |
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2323 | .IP "Stopping check/prepare/idle watchers: O(1)" 4 |
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2324 | .IX Item "Stopping check/prepare/idle watchers: O(1)" |
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2325 | .IP "Stopping an io/signal/child watcher: O(number_of_watchers_for_this_(fd/signal/pid % \s-1EV_PID_HASHSIZE\s0))" 4 |
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2326 | .IX Item "Stopping an io/signal/child watcher: O(number_of_watchers_for_this_(fd/signal/pid % EV_PID_HASHSIZE))" |
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2327 | .IP "Finding the next timer per loop iteration: O(1)" 4 |
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2328 | .IX Item "Finding the next timer per loop iteration: O(1)" |
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2329 | .IP "Each change on a file descriptor per loop iteration: O(number_of_watchers_for_this_fd)" 4 |
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2330 | .IX Item "Each change on a file descriptor per loop iteration: O(number_of_watchers_for_this_fd)" |
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2331 | .IP "Activating one watcher: O(1)" 4 |
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2332 | .IX Item "Activating one watcher: O(1)" |
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2333 | .RE |
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2334 | .RS 4 |
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2335 | .PD |
1824 | .SH "AUTHOR" |
2336 | .SH "AUTHOR" |
1825 | .IX Header "AUTHOR" |
2337 | .IX Header "AUTHOR" |
1826 | Marc Lehmann <libev@schmorp.de>. |
2338 | Marc Lehmann <libev@schmorp.de>. |