… | |
… | |
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 "2007-11-26" "perl v5.8.8" "User Contributed Perl Documentation" |
132 | .TH "<STANDARD INPUT>" 1 "2007-11-27" "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), relative timers (\f(CW\*(C`ev_timer\*(C'\fR), |
159 | events (related to \s-1SIGCHLD\s0), and event watchers dealing with the event |
218 | absolute timers with customised rescheduling (\f(CW\*(C`ev_periodic\*(C'\fR), synchronous |
160 | loop mechanism itself (idle, prepare and check watchers). It also is quite |
219 | signals (\f(CW\*(C`ev_signal\*(C'\fR), process status change events (\f(CW\*(C`ev_child\*(C'\fR), and |
161 | fast (see this benchmark comparing |
220 | event watchers dealing with the event loop mechanism itself (\f(CW\*(C`ev_idle\*(C'\fR, |
162 | it to libevent for example). |
221 | \&\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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222 | file watchers (\f(CW\*(C`ev_stat\*(C'\fR) and even limited support for fork events |
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223 | (\f(CW\*(C`ev_fork\*(C'\fR). |
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224 | .PP |
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225 | It also is quite fast (see this |
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226 | benchmark comparing it to libevent |
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227 | for example). |
163 | .SH "CONVENTIONS" |
228 | .SH "CONVENTIONS" |
164 | .IX Header "CONVENTIONS" |
229 | .IX Header "CONVENTIONS" |
165 | Libev is very configurable. In this manual the default configuration |
230 | Libev is very configurable. In this manual the default configuration will |
166 | will be described, which supports multiple event loops. For more info |
231 | be described, which supports multiple event loops. For more info about |
167 | about various configuration options please have a look at the file |
232 | 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 |
233 | this manual. If libev was configured without support for multiple event |
169 | support for multiple event loops, then all functions taking an initial |
234 | 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) |
235 | (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" |
236 | .SH "TIME REPRESENTATION" |
173 | .IX Header "TIME REPRESENTATION" |
237 | .IX Header "TIME REPRESENTATION" |
174 | Libev represents time as a single floating point number, representing the |
238 | Libev represents time as a single floating point number, representing the |
175 | (fractional) number of seconds since the (\s-1POSIX\s0) epoch (somewhere near |
239 | (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 |
240 | 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, |
265 | Usually, it's a good idea to terminate if the major versions mismatch, |
202 | as this indicates an incompatible change. Minor versions are usually |
266 | as this indicates an incompatible change. Minor versions are usually |
203 | compatible to older versions, so a larger minor version alone is usually |
267 | compatible to older versions, so a larger minor version alone is usually |
204 | not a problem. |
268 | not a problem. |
205 | .Sp |
269 | .Sp |
206 | Example: make sure we haven't accidentally been linked against the wrong |
270 | Example: Make sure we haven't accidentally been linked against the wrong |
207 | version: |
271 | version. |
208 | .Sp |
272 | .Sp |
209 | .Vb 3 |
273 | .Vb 3 |
210 | \& assert (("libev version mismatch", |
274 | \& assert (("libev version mismatch", |
211 | \& ev_version_major () == EV_VERSION_MAJOR |
275 | \& ev_version_major () == EV_VERSION_MAJOR |
212 | \& && ev_version_minor () >= EV_VERSION_MINOR)); |
276 | \& && ev_version_minor () >= EV_VERSION_MINOR)); |
… | |
… | |
240 | might be supported on the current system, you would need to look at |
304 | might be supported on the current system, you would need to look at |
241 | \&\f(CW\*(C`ev_embeddable_backends () & ev_supported_backends ()\*(C'\fR, likewise for |
305 | \&\f(CW\*(C`ev_embeddable_backends () & ev_supported_backends ()\*(C'\fR, likewise for |
242 | recommended ones. |
306 | recommended ones. |
243 | .Sp |
307 | .Sp |
244 | See the description of \f(CW\*(C`ev_embed\*(C'\fR watchers for more info. |
308 | 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 |
309 | .IP "ev_set_allocator (void *(*cb)(void *ptr, size_t size))" 4 |
246 | .IX Item "ev_set_allocator (void *(*cb)(void *ptr, long size))" |
310 | .IX Item "ev_set_allocator (void *(*cb)(void *ptr, size_t size))" |
247 | Sets the allocation function to use (the prototype is similar to the |
311 | Sets the allocation function to use (the prototype and semantics are |
248 | realloc C function, the semantics are identical). It is used to allocate |
312 | identical to the realloc C function). It is used to allocate and free |
249 | and free memory (no surprises here). If it returns zero when memory |
313 | memory (no surprises here). If it returns zero when memory needs to be |
250 | needs to be allocated, the library might abort or take some potentially |
314 | allocated, the library might abort or take some potentially destructive |
251 | destructive action. The default is your system realloc function. |
315 | action. The default is your system realloc function. |
252 | .Sp |
316 | .Sp |
253 | You could override this function in high-availability programs to, say, |
317 | 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, |
318 | 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. |
319 | or even to sleep a while and retry until some memory is available. |
256 | .Sp |
320 | .Sp |
257 | Example: replace the libev allocator with one that waits a bit and then |
321 | Example: Replace the libev allocator with one that waits a bit and then |
258 | retries: better than mine). |
322 | retries). |
259 | .Sp |
323 | .Sp |
260 | .Vb 6 |
324 | .Vb 6 |
261 | \& static void * |
325 | \& static void * |
262 | \& persistent_realloc (void *ptr, long size) |
326 | \& persistent_realloc (void *ptr, size_t size) |
263 | \& { |
327 | \& { |
264 | \& for (;;) |
328 | \& for (;;) |
265 | \& { |
329 | \& { |
266 | \& void *newptr = realloc (ptr, size); |
330 | \& void *newptr = realloc (ptr, size); |
267 | .Ve |
331 | .Ve |
… | |
… | |
289 | callback is set, then libev will expect it to remedy the sitution, no |
353 | 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 |
354 | 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 |
355 | requested operation, or, if the condition doesn't go away, do bad stuff |
292 | (such as abort). |
356 | (such as abort). |
293 | .Sp |
357 | .Sp |
294 | Example: do the same thing as libev does internally: |
358 | Example: This is basically the same thing that libev does internally, too. |
295 | .Sp |
359 | .Sp |
296 | .Vb 6 |
360 | .Vb 6 |
297 | \& static void |
361 | \& static void |
298 | \& fatal_error (const char *msg) |
362 | \& fatal_error (const char *msg) |
299 | \& { |
363 | \& { |
… | |
… | |
448 | Similar to \f(CW\*(C`ev_default_loop\*(C'\fR, but always creates a new event loop that is |
512 | 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 |
513 | 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 |
514 | 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). |
515 | undefined behaviour (or a failed assertion if assertions are enabled). |
452 | .Sp |
516 | .Sp |
453 | Example: try to create a event loop that uses epoll and nothing else. |
517 | Example: Try to create a event loop that uses epoll and nothing else. |
454 | .Sp |
518 | .Sp |
455 | .Vb 3 |
519 | .Vb 3 |
456 | \& struct ev_loop *epoller = ev_loop_new (EVBACKEND_EPOLL | EVFLAG_NOENV); |
520 | \& struct ev_loop *epoller = ev_loop_new (EVBACKEND_EPOLL | EVFLAG_NOENV); |
457 | \& if (!epoller) |
521 | \& if (!epoller) |
458 | \& fatal ("no epoll found here, maybe it hides under your chair"); |
522 | \& fatal ("no epoll found here, maybe it hides under your chair"); |
… | |
… | |
556 | \& be handled here by queueing them when their watcher gets executed. |
620 | \& be handled here by queueing them when their watcher gets executed. |
557 | \& - If ev_unloop has been called or EVLOOP_ONESHOT or EVLOOP_NONBLOCK |
621 | \& - If ev_unloop has been called or EVLOOP_ONESHOT or EVLOOP_NONBLOCK |
558 | \& were used, return, otherwise continue with step *. |
622 | \& were used, return, otherwise continue with step *. |
559 | .Ve |
623 | .Ve |
560 | .Sp |
624 | .Sp |
561 | Example: queue some jobs and then loop until no events are outsanding |
625 | Example: Queue some jobs and then loop until no events are outsanding |
562 | anymore. |
626 | anymore. |
563 | .Sp |
627 | .Sp |
564 | .Vb 4 |
628 | .Vb 4 |
565 | \& ... queue jobs here, make sure they register event watchers as long |
629 | \& ... 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..) |
630 | \& ... 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 |
652 | 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 |
653 | 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 |
654 | 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. |
655 | libraries. Just remember to \fIunref after start\fR and \fIref before stop\fR. |
592 | .Sp |
656 | .Sp |
593 | Example: create a signal watcher, but keep it from keeping \f(CW\*(C`ev_loop\*(C'\fR |
657 | Example: Create a signal watcher, but keep it from keeping \f(CW\*(C`ev_loop\*(C'\fR |
594 | running when nothing else is active. |
658 | running when nothing else is active. |
595 | .Sp |
659 | .Sp |
596 | .Vb 4 |
660 | .Vb 4 |
597 | \& struct dv_signal exitsig; |
661 | \& struct ev_signal exitsig; |
598 | \& ev_signal_init (&exitsig, sig_cb, SIGINT); |
662 | \& ev_signal_init (&exitsig, sig_cb, SIGINT); |
599 | \& ev_signal_start (myloop, &exitsig); |
663 | \& ev_signal_start (loop, &exitsig); |
600 | \& evf_unref (myloop); |
664 | \& evf_unref (loop); |
601 | .Ve |
665 | .Ve |
602 | .Sp |
666 | .Sp |
603 | Example: for some weird reason, unregister the above signal handler again. |
667 | Example: For some weird reason, unregister the above signal handler again. |
604 | .Sp |
668 | .Sp |
605 | .Vb 2 |
669 | .Vb 2 |
606 | \& ev_ref (myloop); |
670 | \& ev_ref (loop); |
607 | \& ev_signal_stop (myloop, &exitsig); |
671 | \& ev_signal_stop (loop, &exitsig); |
608 | .Ve |
672 | .Ve |
609 | .SH "ANATOMY OF A WATCHER" |
673 | .SH "ANATOMY OF A WATCHER" |
610 | .IX Header "ANATOMY OF A WATCHER" |
674 | .IX Header "ANATOMY OF A WATCHER" |
611 | A watcher is a structure that you create and register to record your |
675 | 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 |
676 | 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. |
748 | 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 |
749 | .ie n .IP """EV_CHILD""" 4 |
686 | .el .IP "\f(CWEV_CHILD\fR" 4 |
750 | .el .IP "\f(CWEV_CHILD\fR" 4 |
687 | .IX Item "EV_CHILD" |
751 | .IX Item "EV_CHILD" |
688 | The pid specified in the \f(CW\*(C`ev_child\*(C'\fR watcher has received a status change. |
752 | The pid specified in the \f(CW\*(C`ev_child\*(C'\fR watcher has received a status change. |
|
|
753 | .ie n .IP """EV_STAT""" 4 |
|
|
754 | .el .IP "\f(CWEV_STAT\fR" 4 |
|
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755 | .IX Item "EV_STAT" |
|
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756 | The path specified in the \f(CW\*(C`ev_stat\*(C'\fR watcher changed its attributes somehow. |
689 | .ie n .IP """EV_IDLE""" 4 |
757 | .ie n .IP """EV_IDLE""" 4 |
690 | .el .IP "\f(CWEV_IDLE\fR" 4 |
758 | .el .IP "\f(CWEV_IDLE\fR" 4 |
691 | .IX Item "EV_IDLE" |
759 | .IX Item "EV_IDLE" |
692 | The \f(CW\*(C`ev_idle\*(C'\fR watcher has determined that you have nothing better to do. |
760 | 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 |
761 | .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 |
771 | \&\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 |
772 | 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 |
773 | 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 |
774 | (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). |
775 | \&\f(CW\*(C`ev_loop\*(C'\fR from blocking). |
|
|
776 | .ie n .IP """EV_EMBED""" 4 |
|
|
777 | .el .IP "\f(CWEV_EMBED\fR" 4 |
|
|
778 | .IX Item "EV_EMBED" |
|
|
779 | The embedded event loop specified in the \f(CW\*(C`ev_embed\*(C'\fR watcher needs attention. |
|
|
780 | .ie n .IP """EV_FORK""" 4 |
|
|
781 | .el .IP "\f(CWEV_FORK\fR" 4 |
|
|
782 | .IX Item "EV_FORK" |
|
|
783 | The event loop has been resumed in the child process after fork (see |
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|
784 | \&\f(CW\*(C`ev_fork\*(C'\fR). |
708 | .ie n .IP """EV_ERROR""" 4 |
785 | .ie n .IP """EV_ERROR""" 4 |
709 | .el .IP "\f(CWEV_ERROR\fR" 4 |
786 | .el .IP "\f(CWEV_ERROR\fR" 4 |
710 | .IX Item "EV_ERROR" |
787 | .IX Item "EV_ERROR" |
711 | An unspecified error has occured, the watcher has been stopped. This might |
788 | An unspecified error has occured, the watcher has been stopped. This might |
712 | happen because the watcher could not be properly started because libev |
789 | happen because the watcher could not be properly started because libev |
… | |
… | |
821 | More interesting and less C\-conformant ways of catsing your callback type |
898 | More interesting and less C\-conformant ways of catsing your callback type |
822 | have been omitted.... |
899 | have been omitted.... |
823 | .SH "WATCHER TYPES" |
900 | .SH "WATCHER TYPES" |
824 | .IX Header "WATCHER TYPES" |
901 | .IX Header "WATCHER TYPES" |
825 | This section describes each watcher in detail, but will not repeat |
902 | This section describes each watcher in detail, but will not repeat |
826 | information given in the last section. |
903 | information given in the last section. Any initialisation/set macros, |
|
|
904 | functions and members specific to the watcher type are explained. |
|
|
905 | .PP |
|
|
906 | Members are additionally marked with either \fI[read\-only]\fR, meaning that, |
|
|
907 | while the watcher is active, you can look at the member and expect some |
|
|
908 | sensible content, but you must not modify it (you can modify it while the |
|
|
909 | watcher is stopped to your hearts content), or \fI[read\-write]\fR, which |
|
|
910 | means you can expect it to have some sensible content while the watcher |
|
|
911 | is active, but you can also modify it. Modifying it may not do something |
|
|
912 | sensible or take immediate effect (or do anything at all), but libev will |
|
|
913 | not crash or malfunction in any way. |
827 | .ie n .Sh """ev_io"" \- is this file descriptor readable or writable?" |
914 | .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?" |
915 | .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?" |
916 | .IX Subsection "ev_io - is this file descriptor readable or writable?" |
830 | I/O watchers check whether a file descriptor is readable or writable |
917 | 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 |
918 | in each iteration of the event loop, or, more precisely, when reading |
… | |
… | |
871 | .IX Item "ev_io_set (ev_io *, int fd, int events)" |
958 | .IX Item "ev_io_set (ev_io *, int fd, int events)" |
872 | .PD |
959 | .PD |
873 | Configures an \f(CW\*(C`ev_io\*(C'\fR watcher. The \f(CW\*(C`fd\*(C'\fR is the file descriptor to |
960 | 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 |
961 | 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. |
962 | \&\f(CW\*(C`EV_READ | EV_WRITE\*(C'\fR to receive the given events. |
|
|
963 | .IP "int fd [read\-only]" 4 |
|
|
964 | .IX Item "int fd [read-only]" |
|
|
965 | The file descriptor being watched. |
|
|
966 | .IP "int events [read\-only]" 4 |
|
|
967 | .IX Item "int events [read-only]" |
|
|
968 | The events being watched. |
876 | .PP |
969 | .PP |
877 | Example: call \f(CW\*(C`stdin_readable_cb\*(C'\fR when \s-1STDIN_FILENO\s0 has become, well |
970 | 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 |
971 | readable, but only once. Since it is likely line\-buffered, you could |
879 | attempt to read a whole line in the callback: |
972 | attempt to read a whole line in the callback. |
880 | .PP |
973 | .PP |
881 | .Vb 6 |
974 | .Vb 6 |
882 | \& static void |
975 | \& static void |
883 | \& stdin_readable_cb (struct ev_loop *loop, struct ev_io *w, int revents) |
976 | \& stdin_readable_cb (struct ev_loop *loop, struct ev_io *w, int revents) |
884 | \& { |
977 | \& { |
… | |
… | |
945 | .Sp |
1038 | .Sp |
946 | If the timer is repeating, either start it if necessary (with the repeat |
1039 | If the timer is repeating, either start it if necessary (with the repeat |
947 | value), or reset the running timer to the repeat value. |
1040 | value), or reset the running timer to the repeat value. |
948 | .Sp |
1041 | .Sp |
949 | This sounds a bit complicated, but here is a useful and typical |
1042 | 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 |
1043 | 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 |
1044 | 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 |
1045 | 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 |
1046 | 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 |
1047 | \&\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 |
1048 | 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. |
1049 | socket, you can stop the timer, and again will automatically restart it if |
|
|
1050 | need be. |
|
|
1051 | .Sp |
|
|
1052 | You can also ignore the \f(CW\*(C`after\*(C'\fR value and \f(CW\*(C`ev_timer_start\*(C'\fR altogether |
|
|
1053 | and only ever use the \f(CW\*(C`repeat\*(C'\fR value: |
|
|
1054 | .Sp |
|
|
1055 | .Vb 8 |
|
|
1056 | \& ev_timer_init (timer, callback, 0., 5.); |
|
|
1057 | \& ev_timer_again (loop, timer); |
|
|
1058 | \& ... |
|
|
1059 | \& timer->again = 17.; |
|
|
1060 | \& ev_timer_again (loop, timer); |
|
|
1061 | \& ... |
|
|
1062 | \& timer->again = 10.; |
|
|
1063 | \& ev_timer_again (loop, timer); |
|
|
1064 | .Ve |
|
|
1065 | .Sp |
|
|
1066 | This is more efficient then stopping/starting the timer eahc time you want |
|
|
1067 | to modify its timeout value. |
|
|
1068 | .IP "ev_tstamp repeat [read\-write]" 4 |
|
|
1069 | .IX Item "ev_tstamp repeat [read-write]" |
|
|
1070 | The current \f(CW\*(C`repeat\*(C'\fR value. Will be used each time the watcher times out |
|
|
1071 | or \f(CW\*(C`ev_timer_again\*(C'\fR is called and determines the next timeout (if any), |
|
|
1072 | which is also when any modifications are taken into account. |
957 | .PP |
1073 | .PP |
958 | Example: create a timer that fires after 60 seconds. |
1074 | Example: Create a timer that fires after 60 seconds. |
959 | .PP |
1075 | .PP |
960 | .Vb 5 |
1076 | .Vb 5 |
961 | \& static void |
1077 | \& static void |
962 | \& one_minute_cb (struct ev_loop *loop, struct ev_timer *w, int revents) |
1078 | \& one_minute_cb (struct ev_loop *loop, struct ev_timer *w, int revents) |
963 | \& { |
1079 | \& { |
… | |
… | |
969 | \& struct ev_timer mytimer; |
1085 | \& struct ev_timer mytimer; |
970 | \& ev_timer_init (&mytimer, one_minute_cb, 60., 0.); |
1086 | \& ev_timer_init (&mytimer, one_minute_cb, 60., 0.); |
971 | \& ev_timer_start (loop, &mytimer); |
1087 | \& ev_timer_start (loop, &mytimer); |
972 | .Ve |
1088 | .Ve |
973 | .PP |
1089 | .PP |
974 | Example: create a timeout timer that times out after 10 seconds of |
1090 | Example: Create a timeout timer that times out after 10 seconds of |
975 | inactivity. |
1091 | inactivity. |
976 | .PP |
1092 | .PP |
977 | .Vb 5 |
1093 | .Vb 5 |
978 | \& static void |
1094 | \& static void |
979 | \& timeout_cb (struct ev_loop *loop, struct ev_timer *w, int revents) |
1095 | \& timeout_cb (struct ev_loop *loop, struct ev_timer *w, int revents) |
… | |
… | |
1093 | .IX Item "ev_periodic_again (loop, ev_periodic *)" |
1209 | .IX Item "ev_periodic_again (loop, ev_periodic *)" |
1094 | Simply stops and restarts the periodic watcher again. This is only useful |
1210 | Simply stops and restarts the periodic watcher again. This is only useful |
1095 | when you changed some parameters or the reschedule callback would return |
1211 | 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 |
1212 | a different time than the last time it was called (e.g. in a crond like |
1097 | program when the crontabs have changed). |
1213 | program when the crontabs have changed). |
|
|
1214 | .IP "ev_tstamp interval [read\-write]" 4 |
|
|
1215 | .IX Item "ev_tstamp interval [read-write]" |
|
|
1216 | The current interval value. Can be modified any time, but changes only |
|
|
1217 | take effect when the periodic timer fires or \f(CW\*(C`ev_periodic_again\*(C'\fR is being |
|
|
1218 | called. |
|
|
1219 | .IP "ev_tstamp (*reschedule_cb)(struct ev_periodic *w, ev_tstamp now) [read\-write]" 4 |
|
|
1220 | .IX Item "ev_tstamp (*reschedule_cb)(struct ev_periodic *w, ev_tstamp now) [read-write]" |
|
|
1221 | The current reschedule callback, or \f(CW0\fR, if this functionality is |
|
|
1222 | switched off. Can be changed any time, but changes only take effect when |
|
|
1223 | the periodic timer fires or \f(CW\*(C`ev_periodic_again\*(C'\fR is being called. |
1098 | .PP |
1224 | .PP |
1099 | Example: call a callback every hour, or, more precisely, whenever the |
1225 | Example: Call a callback every hour, or, more precisely, whenever the |
1100 | system clock is divisible by 3600. The callback invocation times have |
1226 | system clock is divisible by 3600. The callback invocation times have |
1101 | potentially a lot of jittering, but good long-term stability. |
1227 | potentially a lot of jittering, but good long-term stability. |
1102 | .PP |
1228 | .PP |
1103 | .Vb 5 |
1229 | .Vb 5 |
1104 | \& static void |
1230 | \& static void |
… | |
… | |
1112 | \& struct ev_periodic hourly_tick; |
1238 | \& struct ev_periodic hourly_tick; |
1113 | \& ev_periodic_init (&hourly_tick, clock_cb, 0., 3600., 0); |
1239 | \& ev_periodic_init (&hourly_tick, clock_cb, 0., 3600., 0); |
1114 | \& ev_periodic_start (loop, &hourly_tick); |
1240 | \& ev_periodic_start (loop, &hourly_tick); |
1115 | .Ve |
1241 | .Ve |
1116 | .PP |
1242 | .PP |
1117 | Example: the same as above, but use a reschedule callback to do it: |
1243 | Example: The same as above, but use a reschedule callback to do it: |
1118 | .PP |
1244 | .PP |
1119 | .Vb 1 |
1245 | .Vb 1 |
1120 | \& #include <math.h> |
1246 | \& #include <math.h> |
1121 | .Ve |
1247 | .Ve |
1122 | .PP |
1248 | .PP |
… | |
… | |
1130 | .PP |
1256 | .PP |
1131 | .Vb 1 |
1257 | .Vb 1 |
1132 | \& ev_periodic_init (&hourly_tick, clock_cb, 0., 0., my_scheduler_cb); |
1258 | \& ev_periodic_init (&hourly_tick, clock_cb, 0., 0., my_scheduler_cb); |
1133 | .Ve |
1259 | .Ve |
1134 | .PP |
1260 | .PP |
1135 | Example: call a callback every hour, starting now: |
1261 | Example: Call a callback every hour, starting now: |
1136 | .PP |
1262 | .PP |
1137 | .Vb 4 |
1263 | .Vb 4 |
1138 | \& struct ev_periodic hourly_tick; |
1264 | \& struct ev_periodic hourly_tick; |
1139 | \& ev_periodic_init (&hourly_tick, clock_cb, |
1265 | \& ev_periodic_init (&hourly_tick, clock_cb, |
1140 | \& fmod (ev_now (loop), 3600.), 3600., 0); |
1266 | \& fmod (ev_now (loop), 3600.), 3600., 0); |
… | |
… | |
1160 | .IP "ev_signal_set (ev_signal *, int signum)" 4 |
1286 | .IP "ev_signal_set (ev_signal *, int signum)" 4 |
1161 | .IX Item "ev_signal_set (ev_signal *, int signum)" |
1287 | .IX Item "ev_signal_set (ev_signal *, int signum)" |
1162 | .PD |
1288 | .PD |
1163 | Configures the watcher to trigger on the given signal number (usually one |
1289 | Configures the watcher to trigger on the given signal number (usually one |
1164 | of the \f(CW\*(C`SIGxxx\*(C'\fR constants). |
1290 | of the \f(CW\*(C`SIGxxx\*(C'\fR constants). |
|
|
1291 | .IP "int signum [read\-only]" 4 |
|
|
1292 | .IX Item "int signum [read-only]" |
|
|
1293 | The signal the watcher watches out for. |
1165 | .ie n .Sh """ev_child"" \- watch out for process status changes" |
1294 | .ie n .Sh """ev_child"" \- watch out for process status changes" |
1166 | .el .Sh "\f(CWev_child\fP \- watch out for process status changes" |
1295 | .el .Sh "\f(CWev_child\fP \- watch out for process status changes" |
1167 | .IX Subsection "ev_child - watch out for process status changes" |
1296 | .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 |
1297 | 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). |
1298 | 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 |
1306 | \&\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 |
1307 | 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 |
1308 | 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 |
1309 | \&\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. |
1310 | process causing the status change. |
|
|
1311 | .IP "int pid [read\-only]" 4 |
|
|
1312 | .IX Item "int pid [read-only]" |
|
|
1313 | The process id this watcher watches out for, or \f(CW0\fR, meaning any process id. |
|
|
1314 | .IP "int rpid [read\-write]" 4 |
|
|
1315 | .IX Item "int rpid [read-write]" |
|
|
1316 | The process id that detected a status change. |
|
|
1317 | .IP "int rstatus [read\-write]" 4 |
|
|
1318 | .IX Item "int rstatus [read-write]" |
|
|
1319 | The process exit/trace status caused by \f(CW\*(C`rpid\*(C'\fR (see your systems |
|
|
1320 | \&\f(CW\*(C`waitpid\*(C'\fR and \f(CW\*(C`sys/wait.h\*(C'\fR documentation for details). |
1182 | .PP |
1321 | .PP |
1183 | Example: try to exit cleanly on \s-1SIGINT\s0 and \s-1SIGTERM\s0. |
1322 | Example: Try to exit cleanly on \s-1SIGINT\s0 and \s-1SIGTERM\s0. |
1184 | .PP |
1323 | .PP |
1185 | .Vb 5 |
1324 | .Vb 5 |
1186 | \& static void |
1325 | \& static void |
1187 | \& sigint_cb (struct ev_loop *loop, struct ev_signal *w, int revents) |
1326 | \& sigint_cb (struct ev_loop *loop, struct ev_signal *w, int revents) |
1188 | \& { |
1327 | \& { |
… | |
… | |
1192 | .PP |
1331 | .PP |
1193 | .Vb 3 |
1332 | .Vb 3 |
1194 | \& struct ev_signal signal_watcher; |
1333 | \& struct ev_signal signal_watcher; |
1195 | \& ev_signal_init (&signal_watcher, sigint_cb, SIGINT); |
1334 | \& ev_signal_init (&signal_watcher, sigint_cb, SIGINT); |
1196 | \& ev_signal_start (loop, &sigint_cb); |
1335 | \& ev_signal_start (loop, &sigint_cb); |
|
|
1336 | .Ve |
|
|
1337 | .ie n .Sh """ev_stat"" \- did the file attributes just change?" |
|
|
1338 | .el .Sh "\f(CWev_stat\fP \- did the file attributes just change?" |
|
|
1339 | .IX Subsection "ev_stat - did the file attributes just change?" |
|
|
1340 | This watches a filesystem path for attribute changes. That is, it calls |
|
|
1341 | \&\f(CW\*(C`stat\*(C'\fR regularly (or when the \s-1OS\s0 says it changed) and sees if it changed |
|
|
1342 | compared to the last time, invoking the callback if it did. |
|
|
1343 | .PP |
|
|
1344 | The path does not need to exist: changing from \*(L"path exists\*(R" to \*(L"path does |
|
|
1345 | not exist\*(R" is a status change like any other. The condition \*(L"path does |
|
|
1346 | not exist\*(R" is signified by the \f(CW\*(C`st_nlink\*(C'\fR field being zero (which is |
|
|
1347 | otherwise always forced to be at least one) and all the other fields of |
|
|
1348 | the stat buffer having unspecified contents. |
|
|
1349 | .PP |
|
|
1350 | Since there is no standard to do this, the portable implementation simply |
|
|
1351 | calls \f(CW\*(C`stat (2)\*(C'\fR regulalry on the path to see if it changed somehow. You |
|
|
1352 | can specify a recommended polling interval for this case. If you specify |
|
|
1353 | a polling interval of \f(CW0\fR (highly recommended!) then a \fIsuitable, |
|
|
1354 | unspecified default\fR value will be used (which you can expect to be around |
|
|
1355 | five seconds, although this might change dynamically). Libev will also |
|
|
1356 | impose a minimum interval which is currently around \f(CW0.1\fR, but thats |
|
|
1357 | usually overkill. |
|
|
1358 | .PP |
|
|
1359 | This watcher type is not meant for massive numbers of stat watchers, |
|
|
1360 | as even with OS-supported change notifications, this can be |
|
|
1361 | resource\-intensive. |
|
|
1362 | .PP |
|
|
1363 | At the time of this writing, no specific \s-1OS\s0 backends are implemented, but |
|
|
1364 | if demand increases, at least a kqueue and inotify backend will be added. |
|
|
1365 | .IP "ev_stat_init (ev_stat *, callback, const char *path, ev_tstamp interval)" 4 |
|
|
1366 | .IX Item "ev_stat_init (ev_stat *, callback, const char *path, ev_tstamp interval)" |
|
|
1367 | .PD 0 |
|
|
1368 | .IP "ev_stat_set (ev_stat *, const char *path, ev_tstamp interval)" 4 |
|
|
1369 | .IX Item "ev_stat_set (ev_stat *, const char *path, ev_tstamp interval)" |
|
|
1370 | .PD |
|
|
1371 | Configures the watcher to wait for status changes of the given |
|
|
1372 | \&\f(CW\*(C`path\*(C'\fR. The \f(CW\*(C`interval\*(C'\fR is a hint on how quickly a change is expected to |
|
|
1373 | be detected and should normally be specified as \f(CW0\fR to let libev choose |
|
|
1374 | a suitable value. The memory pointed to by \f(CW\*(C`path\*(C'\fR must point to the same |
|
|
1375 | path for as long as the watcher is active. |
|
|
1376 | .Sp |
|
|
1377 | The callback will be receive \f(CW\*(C`EV_STAT\*(C'\fR when a change was detected, |
|
|
1378 | relative to the attributes at the time the watcher was started (or the |
|
|
1379 | last change was detected). |
|
|
1380 | .IP "ev_stat_stat (ev_stat *)" 4 |
|
|
1381 | .IX Item "ev_stat_stat (ev_stat *)" |
|
|
1382 | Updates the stat buffer immediately with new values. If you change the |
|
|
1383 | watched path in your callback, you could call this fucntion to avoid |
|
|
1384 | detecting this change (while introducing a race condition). Can also be |
|
|
1385 | useful simply to find out the new values. |
|
|
1386 | .IP "ev_statdata attr [read\-only]" 4 |
|
|
1387 | .IX Item "ev_statdata attr [read-only]" |
|
|
1388 | The most-recently detected attributes of the file. Although the type is of |
|
|
1389 | \&\f(CW\*(C`ev_statdata\*(C'\fR, this is usually the (or one of the) \f(CW\*(C`struct stat\*(C'\fR types |
|
|
1390 | suitable for your system. If the \f(CW\*(C`st_nlink\*(C'\fR member is \f(CW0\fR, then there |
|
|
1391 | was some error while \f(CW\*(C`stat\*(C'\fRing the file. |
|
|
1392 | .IP "ev_statdata prev [read\-only]" 4 |
|
|
1393 | .IX Item "ev_statdata prev [read-only]" |
|
|
1394 | The previous attributes of the file. The callback gets invoked whenever |
|
|
1395 | \&\f(CW\*(C`prev\*(C'\fR != \f(CW\*(C`attr\*(C'\fR. |
|
|
1396 | .IP "ev_tstamp interval [read\-only]" 4 |
|
|
1397 | .IX Item "ev_tstamp interval [read-only]" |
|
|
1398 | The specified interval. |
|
|
1399 | .IP "const char *path [read\-only]" 4 |
|
|
1400 | .IX Item "const char *path [read-only]" |
|
|
1401 | The filesystem path that is being watched. |
|
|
1402 | .PP |
|
|
1403 | Example: Watch \f(CW\*(C`/etc/passwd\*(C'\fR for attribute changes. |
|
|
1404 | .PP |
|
|
1405 | .Vb 15 |
|
|
1406 | \& static void |
|
|
1407 | \& passwd_cb (struct ev_loop *loop, ev_stat *w, int revents) |
|
|
1408 | \& { |
|
|
1409 | \& /* /etc/passwd changed in some way */ |
|
|
1410 | \& if (w->attr.st_nlink) |
|
|
1411 | \& { |
|
|
1412 | \& printf ("passwd current size %ld\en", (long)w->attr.st_size); |
|
|
1413 | \& printf ("passwd current atime %ld\en", (long)w->attr.st_mtime); |
|
|
1414 | \& printf ("passwd current mtime %ld\en", (long)w->attr.st_mtime); |
|
|
1415 | \& } |
|
|
1416 | \& else |
|
|
1417 | \& /* you shalt not abuse printf for puts */ |
|
|
1418 | \& puts ("wow, /etc/passwd is not there, expect problems. " |
|
|
1419 | \& "if this is windows, they already arrived\en"); |
|
|
1420 | \& } |
|
|
1421 | .Ve |
|
|
1422 | .PP |
|
|
1423 | .Vb 2 |
|
|
1424 | \& ... |
|
|
1425 | \& ev_stat passwd; |
|
|
1426 | .Ve |
|
|
1427 | .PP |
|
|
1428 | .Vb 2 |
|
|
1429 | \& ev_stat_init (&passwd, passwd_cb, "/etc/passwd"); |
|
|
1430 | \& ev_stat_start (loop, &passwd); |
1197 | .Ve |
1431 | .Ve |
1198 | .ie n .Sh """ev_idle"" \- when you've got nothing better to do..." |
1432 | .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..." |
1433 | .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..." |
1434 | .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 |
1435 | Idle watchers trigger events when there are no other events are pending |
… | |
… | |
1217 | .IX Item "ev_idle_init (ev_signal *, callback)" |
1451 | .IX Item "ev_idle_init (ev_signal *, callback)" |
1218 | Initialises and configures the idle watcher \- it has no parameters of any |
1452 | 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, |
1453 | kind. There is a \f(CW\*(C`ev_idle_set\*(C'\fR macro, but using it is utterly pointless, |
1220 | believe me. |
1454 | believe me. |
1221 | .PP |
1455 | .PP |
1222 | Example: dynamically allocate an \f(CW\*(C`ev_idle\*(C'\fR, start it, and in the |
1456 | 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. |
1457 | callback, free it. Also, use no error checking, as usual. |
1224 | .PP |
1458 | .PP |
1225 | .Vb 7 |
1459 | .Vb 7 |
1226 | \& static void |
1460 | \& static void |
1227 | \& idle_cb (struct ev_loop *loop, struct ev_idle *w, int revents) |
1461 | \& idle_cb (struct ev_loop *loop, struct ev_idle *w, int revents) |
1228 | \& { |
1462 | \& { |
… | |
… | |
1449 | .IP "ev_embed_sweep (loop, ev_embed *)" 4 |
1683 | .IP "ev_embed_sweep (loop, ev_embed *)" 4 |
1450 | .IX Item "ev_embed_sweep (loop, ev_embed *)" |
1684 | .IX Item "ev_embed_sweep (loop, ev_embed *)" |
1451 | Make a single, non-blocking sweep over the embedded loop. This works |
1685 | Make a single, non-blocking sweep over the embedded loop. This works |
1452 | similarly to \f(CW\*(C`ev_loop (embedded_loop, EVLOOP_NONBLOCK)\*(C'\fR, but in the most |
1686 | similarly to \f(CW\*(C`ev_loop (embedded_loop, EVLOOP_NONBLOCK)\*(C'\fR, but in the most |
1453 | apropriate way for embedded loops. |
1687 | apropriate way for embedded loops. |
|
|
1688 | .IP "struct ev_loop *loop [read\-only]" 4 |
|
|
1689 | .IX Item "struct ev_loop *loop [read-only]" |
|
|
1690 | The embedded event loop. |
|
|
1691 | .ie n .Sh """ev_fork"" \- the audacity to resume the event loop after a fork" |
|
|
1692 | .el .Sh "\f(CWev_fork\fP \- the audacity to resume the event loop after a fork" |
|
|
1693 | .IX Subsection "ev_fork - the audacity to resume the event loop after a fork" |
|
|
1694 | Fork watchers are called when a \f(CW\*(C`fork ()\*(C'\fR was detected (usually because |
|
|
1695 | whoever is a good citizen cared to tell libev about it by calling |
|
|
1696 | \&\f(CW\*(C`ev_default_fork\*(C'\fR or \f(CW\*(C`ev_loop_fork\*(C'\fR). The invocation is done before the |
|
|
1697 | event loop blocks next and before \f(CW\*(C`ev_check\*(C'\fR watchers are being called, |
|
|
1698 | and only in the child after the fork. If whoever good citizen calling |
|
|
1699 | \&\f(CW\*(C`ev_default_fork\*(C'\fR cheats and calls it in the wrong process, the fork |
|
|
1700 | handlers will be invoked, too, of course. |
|
|
1701 | .IP "ev_fork_init (ev_signal *, callback)" 4 |
|
|
1702 | .IX Item "ev_fork_init (ev_signal *, callback)" |
|
|
1703 | Initialises and configures the fork watcher \- it has no parameters of any |
|
|
1704 | kind. There is a \f(CW\*(C`ev_fork_set\*(C'\fR macro, but using it is utterly pointless, |
|
|
1705 | believe me. |
1454 | .SH "OTHER FUNCTIONS" |
1706 | .SH "OTHER FUNCTIONS" |
1455 | .IX Header "OTHER FUNCTIONS" |
1707 | .IX Header "OTHER FUNCTIONS" |
1456 | There are some other functions of possible interest. Described. Here. Now. |
1708 | There are some other functions of possible interest. Described. Here. Now. |
1457 | .IP "ev_once (loop, int fd, int events, ev_tstamp timeout, callback)" 4 |
1709 | .IP "ev_once (loop, int fd, int events, ev_tstamp timeout, callback)" 4 |
1458 | .IX Item "ev_once (loop, int fd, int events, ev_tstamp timeout, callback)" |
1710 | .IX Item "ev_once (loop, int fd, int events, ev_tstamp timeout, callback)" |
… | |
… | |
1597 | \&\f(CW\*(C`ev_TYPE_again\*(C'\fR function. |
1849 | \&\f(CW\*(C`ev_TYPE_again\*(C'\fR function. |
1598 | .ie n .IP "w\->sweep () ""ev::embed"" only" 4 |
1850 | .ie n .IP "w\->sweep () ""ev::embed"" only" 4 |
1599 | .el .IP "w\->sweep () \f(CWev::embed\fR only" 4 |
1851 | .el .IP "w\->sweep () \f(CWev::embed\fR only" 4 |
1600 | .IX Item "w->sweep () ev::embed only" |
1852 | .IX Item "w->sweep () ev::embed only" |
1601 | Invokes \f(CW\*(C`ev_embed_sweep\*(C'\fR. |
1853 | Invokes \f(CW\*(C`ev_embed_sweep\*(C'\fR. |
|
|
1854 | .ie n .IP "w\->update () ""ev::stat"" only" 4 |
|
|
1855 | .el .IP "w\->update () \f(CWev::stat\fR only" 4 |
|
|
1856 | .IX Item "w->update () ev::stat only" |
|
|
1857 | Invokes \f(CW\*(C`ev_stat_stat\*(C'\fR. |
1602 | .RE |
1858 | .RE |
1603 | .RS 4 |
1859 | .RS 4 |
1604 | .RE |
1860 | .RE |
1605 | .PP |
1861 | .PP |
1606 | Example: Define a class with an \s-1IO\s0 and idle watcher, start one of them in |
1862 | Example: Define a class with an \s-1IO\s0 and idle watcher, start one of them in |
… | |
… | |
1623 | \& : io (this, &myclass::io_cb), |
1879 | \& : io (this, &myclass::io_cb), |
1624 | \& idle (this, &myclass::idle_cb) |
1880 | \& idle (this, &myclass::idle_cb) |
1625 | \& { |
1881 | \& { |
1626 | \& io.start (fd, ev::READ); |
1882 | \& io.start (fd, ev::READ); |
1627 | \& } |
1883 | \& } |
|
|
1884 | .Ve |
|
|
1885 | .SH "MACRO MAGIC" |
|
|
1886 | .IX Header "MACRO MAGIC" |
|
|
1887 | Libev can be compiled with a variety of options, the most fundemantal is |
|
|
1888 | \&\f(CW\*(C`EV_MULTIPLICITY\*(C'\fR. This option determines wether (most) functions and |
|
|
1889 | callbacks have an initial \f(CW\*(C`struct ev_loop *\*(C'\fR argument. |
|
|
1890 | .PP |
|
|
1891 | To make it easier to write programs that cope with either variant, the |
|
|
1892 | following macros are defined: |
|
|
1893 | .ie n .IP """EV_A""\fR, \f(CW""EV_A_""" 4 |
|
|
1894 | .el .IP "\f(CWEV_A\fR, \f(CWEV_A_\fR" 4 |
|
|
1895 | .IX Item "EV_A, EV_A_" |
|
|
1896 | This provides the loop \fIargument\fR for functions, if one is required (\*(L"ev |
|
|
1897 | loop argument\*(R"). The \f(CW\*(C`EV_A\*(C'\fR form is used when this is the sole argument, |
|
|
1898 | \&\f(CW\*(C`EV_A_\*(C'\fR is used when other arguments are following. Example: |
|
|
1899 | .Sp |
|
|
1900 | .Vb 3 |
|
|
1901 | \& ev_unref (EV_A); |
|
|
1902 | \& ev_timer_add (EV_A_ watcher); |
|
|
1903 | \& ev_loop (EV_A_ 0); |
|
|
1904 | .Ve |
|
|
1905 | .Sp |
|
|
1906 | It assumes the variable \f(CW\*(C`loop\*(C'\fR of type \f(CW\*(C`struct ev_loop *\*(C'\fR is in scope, |
|
|
1907 | which is often provided by the following macro. |
|
|
1908 | .ie n .IP """EV_P""\fR, \f(CW""EV_P_""" 4 |
|
|
1909 | .el .IP "\f(CWEV_P\fR, \f(CWEV_P_\fR" 4 |
|
|
1910 | .IX Item "EV_P, EV_P_" |
|
|
1911 | This provides the loop \fIparameter\fR for functions, if one is required (\*(L"ev |
|
|
1912 | loop parameter\*(R"). The \f(CW\*(C`EV_P\*(C'\fR form is used when this is the sole parameter, |
|
|
1913 | \&\f(CW\*(C`EV_P_\*(C'\fR is used when other parameters are following. Example: |
|
|
1914 | .Sp |
|
|
1915 | .Vb 2 |
|
|
1916 | \& // this is how ev_unref is being declared |
|
|
1917 | \& static void ev_unref (EV_P); |
|
|
1918 | .Ve |
|
|
1919 | .Sp |
|
|
1920 | .Vb 2 |
|
|
1921 | \& // this is how you can declare your typical callback |
|
|
1922 | \& static void cb (EV_P_ ev_timer *w, int revents) |
|
|
1923 | .Ve |
|
|
1924 | .Sp |
|
|
1925 | It declares a parameter \f(CW\*(C`loop\*(C'\fR of type \f(CW\*(C`struct ev_loop *\*(C'\fR, quite |
|
|
1926 | suitable for use with \f(CW\*(C`EV_A\*(C'\fR. |
|
|
1927 | .ie n .IP """EV_DEFAULT""\fR, \f(CW""EV_DEFAULT_""" 4 |
|
|
1928 | .el .IP "\f(CWEV_DEFAULT\fR, \f(CWEV_DEFAULT_\fR" 4 |
|
|
1929 | .IX Item "EV_DEFAULT, EV_DEFAULT_" |
|
|
1930 | Similar to the other two macros, this gives you the value of the default |
|
|
1931 | loop, if multiple loops are supported (\*(L"ev loop default\*(R"). |
|
|
1932 | .PP |
|
|
1933 | Example: Declare and initialise a check watcher, working regardless of |
|
|
1934 | wether multiple loops are supported or not. |
|
|
1935 | .PP |
|
|
1936 | .Vb 5 |
|
|
1937 | \& static void |
|
|
1938 | \& check_cb (EV_P_ ev_timer *w, int revents) |
|
|
1939 | \& { |
|
|
1940 | \& ev_check_stop (EV_A_ w); |
|
|
1941 | \& } |
|
|
1942 | .Ve |
|
|
1943 | .PP |
|
|
1944 | .Vb 4 |
|
|
1945 | \& ev_check check; |
|
|
1946 | \& ev_check_init (&check, check_cb); |
|
|
1947 | \& ev_check_start (EV_DEFAULT_ &check); |
|
|
1948 | \& ev_loop (EV_DEFAULT_ 0); |
1628 | .Ve |
1949 | .Ve |
1629 | .SH "EMBEDDING" |
1950 | .SH "EMBEDDING" |
1630 | .IX Header "EMBEDDING" |
1951 | .IX Header "EMBEDDING" |
1631 | Libev can (and often is) directly embedded into host |
1952 | Libev can (and often is) directly embedded into host |
1632 | applications. Examples of applications that embed it include the Deliantra |
1953 | applications. Examples of applications that embed it include the Deliantra |
… | |
… | |
1839 | If undefined or defined to \f(CW1\fR, then all event-loop-specific functions |
2160 | If undefined or defined to \f(CW1\fR, then all event-loop-specific functions |
1840 | will have the \f(CW\*(C`struct ev_loop *\*(C'\fR as first argument, and you can create |
2161 | will have the \f(CW\*(C`struct ev_loop *\*(C'\fR as first argument, and you can create |
1841 | additional independent event loops. Otherwise there will be no support |
2162 | additional independent event loops. Otherwise there will be no support |
1842 | for multiple event loops and there is no first event loop pointer |
2163 | for multiple event loops and there is no first event loop pointer |
1843 | argument. Instead, all functions act on the single default loop. |
2164 | argument. Instead, all functions act on the single default loop. |
1844 | .IP "\s-1EV_PERIODICS\s0" 4 |
2165 | .IP "\s-1EV_PERIODIC_ENABLE\s0" 4 |
1845 | .IX Item "EV_PERIODICS" |
2166 | .IX Item "EV_PERIODIC_ENABLE" |
1846 | If undefined or defined to be \f(CW1\fR, then periodic timers are supported, |
2167 | If undefined or defined to be \f(CW1\fR, then periodic timers are supported. If |
1847 | otherwise not. This saves a few kb of code. |
2168 | defined to be \f(CW0\fR, then they are not. Disabling them saves a few kB of |
|
|
2169 | code. |
|
|
2170 | .IP "\s-1EV_EMBED_ENABLE\s0" 4 |
|
|
2171 | .IX Item "EV_EMBED_ENABLE" |
|
|
2172 | If undefined or defined to be \f(CW1\fR, then embed watchers are supported. If |
|
|
2173 | defined to be \f(CW0\fR, then they are not. |
|
|
2174 | .IP "\s-1EV_STAT_ENABLE\s0" 4 |
|
|
2175 | .IX Item "EV_STAT_ENABLE" |
|
|
2176 | If undefined or defined to be \f(CW1\fR, then stat watchers are supported. If |
|
|
2177 | defined to be \f(CW0\fR, then they are not. |
|
|
2178 | .IP "\s-1EV_FORK_ENABLE\s0" 4 |
|
|
2179 | .IX Item "EV_FORK_ENABLE" |
|
|
2180 | If undefined or defined to be \f(CW1\fR, then fork watchers are supported. If |
|
|
2181 | defined to be \f(CW0\fR, then they are not. |
|
|
2182 | .IP "\s-1EV_MINIMAL\s0" 4 |
|
|
2183 | .IX Item "EV_MINIMAL" |
|
|
2184 | If you need to shave off some kilobytes of code at the expense of some |
|
|
2185 | speed, define this symbol to \f(CW1\fR. Currently only used for gcc to override |
|
|
2186 | some inlining decisions, saves roughly 30% codesize of amd64. |
|
|
2187 | .IP "\s-1EV_PID_HASHSIZE\s0" 4 |
|
|
2188 | .IX Item "EV_PID_HASHSIZE" |
|
|
2189 | \&\f(CW\*(C`ev_child\*(C'\fR watchers use a small hash table to distribute workload by |
|
|
2190 | pid. The default size is \f(CW16\fR (or \f(CW1\fR with \f(CW\*(C`EV_MINIMAL\*(C'\fR), usually more |
|
|
2191 | than enough. If you need to manage thousands of children you might want to |
|
|
2192 | increase this value. |
1848 | .IP "\s-1EV_COMMON\s0" 4 |
2193 | .IP "\s-1EV_COMMON\s0" 4 |
1849 | .IX Item "EV_COMMON" |
2194 | .IX Item "EV_COMMON" |
1850 | By default, all watchers have a \f(CW\*(C`void *data\*(C'\fR member. By redefining |
2195 | By default, all watchers have a \f(CW\*(C`void *data\*(C'\fR member. By redefining |
1851 | this macro to a something else you can include more and other types of |
2196 | this macro to a something else you can include more and other types of |
1852 | members. You have to define it each time you include one of the files, |
2197 | members. You have to define it each time you include one of the files, |