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129 | .\" ======================================================================== |
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133 | .\" |
131 | .IX Title "EV 1" |
134 | .IX Title "EV 1" |
132 | .TH EV 1 "2007-12-25" "perl v5.8.8" "User Contributed Perl Documentation" |
135 | .TH EV 1 "2008-01-28" "perl v5.10.0" "User Contributed Perl Documentation" |
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136 | .\" For nroff, turn off justification. Always turn off hyphenation; it makes |
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137 | .\" way too many mistakes in technical documents. |
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138 | .if n .ad l |
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139 | .nh |
133 | .SH "NAME" |
140 | .SH "NAME" |
134 | libev \- a high performance full\-featured event loop written in C |
141 | libev \- a high performance full\-featured event loop written in C |
135 | .SH "SYNOPSIS" |
142 | .SH "SYNOPSIS" |
136 | .IX Header "SYNOPSIS" |
143 | .IX Header "SYNOPSIS" |
137 | .Vb 1 |
144 | .Vb 1 |
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139 | .Ve |
146 | .Ve |
140 | .Sh "\s-1EXAMPLE\s0 \s-1PROGRAM\s0" |
147 | .Sh "\s-1EXAMPLE\s0 \s-1PROGRAM\s0" |
141 | .IX Subsection "EXAMPLE PROGRAM" |
148 | .IX Subsection "EXAMPLE PROGRAM" |
142 | .Vb 1 |
149 | .Vb 1 |
143 | \& #include <ev.h> |
150 | \& #include <ev.h> |
144 | .Ve |
151 | \& |
145 | .PP |
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146 | .Vb 2 |
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147 | \& ev_io stdin_watcher; |
152 | \& ev_io stdin_watcher; |
148 | \& ev_timer timeout_watcher; |
153 | \& ev_timer timeout_watcher; |
149 | .Ve |
154 | \& |
150 | .PP |
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151 | .Vb 8 |
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152 | \& /* called when data readable on stdin */ |
155 | \& /* called when data readable on stdin */ |
153 | \& static void |
156 | \& static void |
154 | \& stdin_cb (EV_P_ struct ev_io *w, int revents) |
157 | \& stdin_cb (EV_P_ struct ev_io *w, int revents) |
155 | \& { |
158 | \& { |
156 | \& /* puts ("stdin ready"); */ |
159 | \& /* puts ("stdin ready"); */ |
157 | \& ev_io_stop (EV_A_ w); /* just a syntax example */ |
160 | \& ev_io_stop (EV_A_ w); /* just a syntax example */ |
158 | \& ev_unloop (EV_A_ EVUNLOOP_ALL); /* leave all loop calls */ |
161 | \& ev_unloop (EV_A_ EVUNLOOP_ALL); /* leave all loop calls */ |
159 | \& } |
162 | \& } |
160 | .Ve |
163 | \& |
161 | .PP |
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162 | .Vb 6 |
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163 | \& static void |
164 | \& static void |
164 | \& timeout_cb (EV_P_ struct ev_timer *w, int revents) |
165 | \& timeout_cb (EV_P_ struct ev_timer *w, int revents) |
165 | \& { |
166 | \& { |
166 | \& /* puts ("timeout"); */ |
167 | \& /* puts ("timeout"); */ |
167 | \& ev_unloop (EV_A_ EVUNLOOP_ONE); /* leave one loop call */ |
168 | \& ev_unloop (EV_A_ EVUNLOOP_ONE); /* leave one loop call */ |
168 | \& } |
169 | \& } |
169 | .Ve |
170 | \& |
170 | .PP |
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171 | .Vb 4 |
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172 | \& int |
171 | \& int |
173 | \& main (void) |
172 | \& main (void) |
174 | \& { |
173 | \& { |
175 | \& struct ev_loop *loop = ev_default_loop (0); |
174 | \& struct ev_loop *loop = ev_default_loop (0); |
176 | .Ve |
175 | \& |
177 | .PP |
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178 | .Vb 3 |
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179 | \& /* initialise an io watcher, then start it */ |
176 | \& /* initialise an io watcher, then start it */ |
180 | \& ev_io_init (&stdin_watcher, stdin_cb, /*STDIN_FILENO*/ 0, EV_READ); |
177 | \& ev_io_init (&stdin_watcher, stdin_cb, /*STDIN_FILENO*/ 0, EV_READ); |
181 | \& ev_io_start (loop, &stdin_watcher); |
178 | \& ev_io_start (loop, &stdin_watcher); |
182 | .Ve |
179 | \& |
183 | .PP |
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184 | .Vb 3 |
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185 | \& /* simple non-repeating 5.5 second timeout */ |
180 | \& /* simple non\-repeating 5.5 second timeout */ |
186 | \& ev_timer_init (&timeout_watcher, timeout_cb, 5.5, 0.); |
181 | \& ev_timer_init (&timeout_watcher, timeout_cb, 5.5, 0.); |
187 | \& ev_timer_start (loop, &timeout_watcher); |
182 | \& ev_timer_start (loop, &timeout_watcher); |
188 | .Ve |
183 | \& |
189 | .PP |
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190 | .Vb 2 |
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191 | \& /* loop till timeout or data ready */ |
184 | \& /* loop till timeout or data ready */ |
192 | \& ev_loop (loop, 0); |
185 | \& ev_loop (loop, 0); |
193 | .Ve |
186 | \& |
194 | .PP |
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195 | .Vb 2 |
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196 | \& return 0; |
187 | \& return 0; |
197 | \& } |
188 | \& } |
198 | .Ve |
189 | .Ve |
199 | .SH "DESCRIPTION" |
190 | .SH "DESCRIPTION" |
200 | .IX Header "DESCRIPTION" |
191 | .IX Header "DESCRIPTION" |
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313 | (assuming you know what you are doing). This is the set of backends that |
304 | (assuming you know what you are doing). This is the set of backends that |
314 | libev will probe for if you specify no backends explicitly. |
305 | libev will probe for if you specify no backends explicitly. |
315 | .IP "unsigned int ev_embeddable_backends ()" 4 |
306 | .IP "unsigned int ev_embeddable_backends ()" 4 |
316 | .IX Item "unsigned int ev_embeddable_backends ()" |
307 | .IX Item "unsigned int ev_embeddable_backends ()" |
317 | Returns the set of backends that are embeddable in other event loops. This |
308 | Returns the set of backends that are embeddable in other event loops. This |
318 | is the theoretical, all\-platform, value. To find which backends |
309 | is the theoretical, all-platform, value. To find which backends |
319 | might be supported on the current system, you would need to look at |
310 | might be supported on the current system, you would need to look at |
320 | \&\f(CW\*(C`ev_embeddable_backends () & ev_supported_backends ()\*(C'\fR, likewise for |
311 | \&\f(CW\*(C`ev_embeddable_backends () & ev_supported_backends ()\*(C'\fR, likewise for |
321 | recommended ones. |
312 | recommended ones. |
322 | .Sp |
313 | .Sp |
323 | See the description of \f(CW\*(C`ev_embed\*(C'\fR watchers for more info. |
314 | See the description of \f(CW\*(C`ev_embed\*(C'\fR watchers for more info. |
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342 | \& persistent_realloc (void *ptr, size_t size) |
333 | \& persistent_realloc (void *ptr, size_t size) |
343 | \& { |
334 | \& { |
344 | \& for (;;) |
335 | \& for (;;) |
345 | \& { |
336 | \& { |
346 | \& void *newptr = realloc (ptr, size); |
337 | \& void *newptr = realloc (ptr, size); |
347 | .Ve |
338 | \& |
348 | .Sp |
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349 | .Vb 2 |
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350 | \& if (newptr) |
339 | \& if (newptr) |
351 | \& return newptr; |
340 | \& return newptr; |
352 | .Ve |
341 | \& |
353 | .Sp |
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354 | .Vb 3 |
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355 | \& sleep (60); |
342 | \& sleep (60); |
356 | \& } |
343 | \& } |
357 | \& } |
344 | \& } |
358 | .Ve |
345 | \& |
359 | .Sp |
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360 | .Vb 2 |
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361 | \& ... |
346 | \& ... |
362 | \& ev_set_allocator (persistent_realloc); |
347 | \& ev_set_allocator (persistent_realloc); |
363 | .Ve |
348 | .Ve |
364 | .IP "ev_set_syserr_cb (void (*cb)(const char *msg));" 4 |
349 | .IP "ev_set_syserr_cb (void (*cb)(const char *msg));" 4 |
365 | .IX Item "ev_set_syserr_cb (void (*cb)(const char *msg));" |
350 | .IX Item "ev_set_syserr_cb (void (*cb)(const char *msg));" |
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378 | \& fatal_error (const char *msg) |
363 | \& fatal_error (const char *msg) |
379 | \& { |
364 | \& { |
380 | \& perror (msg); |
365 | \& perror (msg); |
381 | \& abort (); |
366 | \& abort (); |
382 | \& } |
367 | \& } |
383 | .Ve |
368 | \& |
384 | .Sp |
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385 | .Vb 2 |
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386 | \& ... |
369 | \& ... |
387 | \& ev_set_syserr_cb (fatal_error); |
370 | \& ev_set_syserr_cb (fatal_error); |
388 | .Ve |
371 | .Ve |
389 | .SH "FUNCTIONS CONTROLLING THE EVENT LOOP" |
372 | .SH "FUNCTIONS CONTROLLING THE EVENT LOOP" |
390 | .IX Header "FUNCTIONS CONTROLLING THE EVENT LOOP" |
373 | .IX Header "FUNCTIONS CONTROLLING THE EVENT LOOP" |
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405 | false. If it already was initialised it simply returns it (and ignores the |
388 | false. If it already was initialised it simply returns it (and ignores the |
406 | flags. If that is troubling you, check \f(CW\*(C`ev_backend ()\*(C'\fR afterwards). |
389 | flags. If that is troubling you, check \f(CW\*(C`ev_backend ()\*(C'\fR afterwards). |
407 | .Sp |
390 | .Sp |
408 | If you don't know what event loop to use, use the one returned from this |
391 | If you don't know what event loop to use, use the one returned from this |
409 | function. |
392 | function. |
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393 | .Sp |
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394 | The default loop is the only loop that can handle \f(CW\*(C`ev_signal\*(C'\fR and |
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395 | \&\f(CW\*(C`ev_child\*(C'\fR watchers, and to do this, it always registers a handler |
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396 | for \f(CW\*(C`SIGCHLD\*(C'\fR. If this is a problem for your app you can either |
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397 | create a dynamic loop with \f(CW\*(C`ev_loop_new\*(C'\fR that doesn't do that, or you |
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398 | can simply overwrite the \f(CW\*(C`SIGCHLD\*(C'\fR signal handler \fIafter\fR calling |
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399 | \&\f(CW\*(C`ev_default_init\*(C'\fR. |
410 | .Sp |
400 | .Sp |
411 | The flags argument can be used to specify special behaviour or specific |
401 | The flags argument can be used to specify special behaviour or specific |
412 | backends to use, and is usually specified as \f(CW0\fR (or \f(CW\*(C`EVFLAG_AUTO\*(C'\fR). |
402 | backends to use, and is usually specified as \f(CW0\fR (or \f(CW\*(C`EVFLAG_AUTO\*(C'\fR). |
413 | .Sp |
403 | .Sp |
414 | The following flags are supported: |
404 | The following flags are supported: |
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452 | .IX Item "EVBACKEND_SELECT (value 1, portable select backend)" |
442 | .IX Item "EVBACKEND_SELECT (value 1, portable select backend)" |
453 | This is your standard \fIselect\fR\|(2) backend. Not \fIcompletely\fR standard, as |
443 | This is your standard \fIselect\fR\|(2) backend. Not \fIcompletely\fR standard, as |
454 | libev tries to roll its own fd_set with no limits on the number of fds, |
444 | libev tries to roll its own fd_set with no limits on the number of fds, |
455 | but if that fails, expect a fairly low limit on the number of fds when |
445 | but if that fails, expect a fairly low limit on the number of fds when |
456 | using this backend. It doesn't scale too well (O(highest_fd)), but its |
446 | using this backend. It doesn't scale too well (O(highest_fd)), but its |
457 | usually the fastest backend for a low number of (low\-numbered :) fds. |
447 | usually the fastest backend for a low number of (low-numbered :) fds. |
458 | .Sp |
448 | .Sp |
459 | To get good performance out of this backend you need a high amount of |
449 | To get good performance out of this backend you need a high amount of |
460 | parallelity (most of the file descriptors should be busy). If you are |
450 | parallelity (most of the file descriptors should be busy). If you are |
461 | writing a server, you should \f(CW\*(C`accept ()\*(C'\fR in a loop to accept as many |
451 | writing a server, you should \f(CW\*(C`accept ()\*(C'\fR in a loop to accept as many |
462 | connections as possible during one iteration. You might also want to have |
452 | connections as possible during one iteration. You might also want to have |
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547 | .Sp |
537 | .Sp |
548 | While this backend scales well, it requires one system call per active |
538 | While this backend scales well, it requires one system call per active |
549 | file descriptor per loop iteration. For small and medium numbers of file |
539 | file descriptor per loop iteration. For small and medium numbers of file |
550 | descriptors a \*(L"slow\*(R" \f(CW\*(C`EVBACKEND_SELECT\*(C'\fR or \f(CW\*(C`EVBACKEND_POLL\*(C'\fR backend |
540 | descriptors a \*(L"slow\*(R" \f(CW\*(C`EVBACKEND_SELECT\*(C'\fR or \f(CW\*(C`EVBACKEND_POLL\*(C'\fR backend |
551 | might perform better. |
541 | might perform better. |
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542 | .Sp |
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543 | On the positive side, ignoring the spurious readyness notifications, this |
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544 | backend actually performed to specification in all tests and is fully |
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545 | embeddable, which is a rare feat among the OS-specific backends. |
552 | .ie n .IP """EVBACKEND_ALL""" 4 |
546 | .ie n .IP """EVBACKEND_ALL""" 4 |
553 | .el .IP "\f(CWEVBACKEND_ALL\fR" 4 |
547 | .el .IP "\f(CWEVBACKEND_ALL\fR" 4 |
554 | .IX Item "EVBACKEND_ALL" |
548 | .IX Item "EVBACKEND_ALL" |
555 | Try all backends (even potentially broken ones that wouldn't be tried |
549 | Try all backends (even potentially broken ones that wouldn't be tried |
556 | with \f(CW\*(C`EVFLAG_AUTO\*(C'\fR). Since this is a mask, you can do stuff such as |
550 | with \f(CW\*(C`EVFLAG_AUTO\*(C'\fR). Since this is a mask, you can do stuff such as |
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559 | It is definitely not recommended to use this flag. |
553 | It is definitely not recommended to use this flag. |
560 | .RE |
554 | .RE |
561 | .RS 4 |
555 | .RS 4 |
562 | .Sp |
556 | .Sp |
563 | If one or more of these are ored into the flags value, then only these |
557 | If one or more of these are ored into the flags value, then only these |
564 | backends will be tried (in the reverse order as given here). If none are |
558 | backends will be tried (in the reverse order as listed here). If none are |
565 | specified, most compiled-in backend will be tried, usually in reverse |
559 | specified, all backends in \f(CW\*(C`ev_recommended_backends ()\*(C'\fR will be tried. |
566 | order of their flag values :) |
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567 | .Sp |
560 | .Sp |
568 | The most typical usage is like this: |
561 | The most typical usage is like this: |
569 | .Sp |
562 | .Sp |
570 | .Vb 2 |
563 | .Vb 2 |
571 | \& if (!ev_default_loop (0)) |
564 | \& if (!ev_default_loop (0)) |
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623 | .IX Item "ev_loop_destroy (loop)" |
616 | .IX Item "ev_loop_destroy (loop)" |
624 | Like \f(CW\*(C`ev_default_destroy\*(C'\fR, but destroys an event loop created by an |
617 | Like \f(CW\*(C`ev_default_destroy\*(C'\fR, but destroys an event loop created by an |
625 | earlier call to \f(CW\*(C`ev_loop_new\*(C'\fR. |
618 | earlier call to \f(CW\*(C`ev_loop_new\*(C'\fR. |
626 | .IP "ev_default_fork ()" 4 |
619 | .IP "ev_default_fork ()" 4 |
627 | .IX Item "ev_default_fork ()" |
620 | .IX Item "ev_default_fork ()" |
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621 | This function sets a flag that causes subsequent \f(CW\*(C`ev_loop\*(C'\fR iterations |
628 | This function reinitialises the kernel state for backends that have |
622 | to reinitialise the kernel state for backends that have one. Despite the |
629 | one. Despite the name, you can call it anytime, but it makes most sense |
623 | name, you can call it anytime, but it makes most sense after forking, in |
630 | after forking, in either the parent or child process (or both, but that |
624 | the child process (or both child and parent, but that again makes little |
631 | again makes little sense). |
625 | sense). You \fImust\fR call it in the child before using any of the libev |
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626 | functions, and it will only take effect at the next \f(CW\*(C`ev_loop\*(C'\fR iteration. |
632 | .Sp |
627 | .Sp |
633 | You \fImust\fR call this function in the child process after forking if and |
628 | On the other hand, you only need to call this function in the child |
634 | only if you want to use the event library in both processes. If you just |
629 | process if and only if you want to use the event library in the child. If |
635 | fork+exec, you don't have to call it. |
630 | you just fork+exec, you don't have to call it at all. |
636 | .Sp |
631 | .Sp |
637 | The function itself is quite fast and it's usually not a problem to call |
632 | The function itself is quite fast and it's usually not a problem to call |
638 | it just in case after a fork. To make this easy, the function will fit in |
633 | it just in case after a fork. To make this easy, the function will fit in |
639 | quite nicely into a call to \f(CW\*(C`pthread_atfork\*(C'\fR: |
634 | quite nicely into a call to \f(CW\*(C`pthread_atfork\*(C'\fR: |
640 | .Sp |
635 | .Sp |
641 | .Vb 1 |
636 | .Vb 1 |
642 | \& pthread_atfork (0, 0, ev_default_fork); |
637 | \& pthread_atfork (0, 0, ev_default_fork); |
643 | .Ve |
638 | .Ve |
644 | .Sp |
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645 | At the moment, \f(CW\*(C`EVBACKEND_SELECT\*(C'\fR and \f(CW\*(C`EVBACKEND_POLL\*(C'\fR are safe to use |
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646 | without calling this function, so if you force one of those backends you |
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647 | do not need to care. |
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648 | .IP "ev_loop_fork (loop)" 4 |
639 | .IP "ev_loop_fork (loop)" 4 |
649 | .IX Item "ev_loop_fork (loop)" |
640 | .IX Item "ev_loop_fork (loop)" |
650 | Like \f(CW\*(C`ev_default_fork\*(C'\fR, but acts on an event loop created by |
641 | Like \f(CW\*(C`ev_default_fork\*(C'\fR, but acts on an event loop created by |
651 | \&\f(CW\*(C`ev_loop_new\*(C'\fR. Yes, you have to call this on every allocated event loop |
642 | \&\f(CW\*(C`ev_loop_new\*(C'\fR. Yes, you have to call this on every allocated event loop |
652 | after fork, and how you do this is entirely your own problem. |
643 | after fork, and how you do this is entirely your own problem. |
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697 | libev watchers. However, a pair of \f(CW\*(C`ev_prepare\*(C'\fR/\f(CW\*(C`ev_check\*(C'\fR watchers is |
688 | libev watchers. However, a pair of \f(CW\*(C`ev_prepare\*(C'\fR/\f(CW\*(C`ev_check\*(C'\fR watchers is |
698 | usually a better approach for this kind of thing. |
689 | usually a better approach for this kind of thing. |
699 | .Sp |
690 | .Sp |
700 | Here are the gory details of what \f(CW\*(C`ev_loop\*(C'\fR does: |
691 | Here are the gory details of what \f(CW\*(C`ev_loop\*(C'\fR does: |
701 | .Sp |
692 | .Sp |
702 | .Vb 19 |
693 | .Vb 10 |
703 | \& - Before the first iteration, call any pending watchers. |
694 | \& \- Before the first iteration, call any pending watchers. |
704 | \& * If there are no active watchers (reference count is zero), return. |
695 | \& * If EVFLAG_FORKCHECK was used, check for a fork. |
705 | \& - Queue all prepare watchers and then call all outstanding watchers. |
696 | \& \- If a fork was detected, queue and call all fork watchers. |
|
|
697 | \& \- Queue and call all prepare watchers. |
706 | \& - If we have been forked, recreate the kernel state. |
698 | \& \- If we have been forked, recreate the kernel state. |
707 | \& - Update the kernel state with all outstanding changes. |
699 | \& \- Update the kernel state with all outstanding changes. |
708 | \& - Update the "event loop time". |
700 | \& \- Update the "event loop time". |
709 | \& - Calculate for how long to block. |
701 | \& \- Calculate for how long to sleep or block, if at all |
|
|
702 | \& (active idle watchers, EVLOOP_NONBLOCK or not having |
|
|
703 | \& any active watchers at all will result in not sleeping). |
|
|
704 | \& \- Sleep if the I/O and timer collect interval say so. |
710 | \& - Block the process, waiting for any events. |
705 | \& \- Block the process, waiting for any events. |
711 | \& - Queue all outstanding I/O (fd) events. |
706 | \& \- Queue all outstanding I/O (fd) events. |
712 | \& - Update the "event loop time" and do time jump handling. |
707 | \& \- Update the "event loop time" and do time jump handling. |
713 | \& - Queue all outstanding timers. |
708 | \& \- Queue all outstanding timers. |
714 | \& - Queue all outstanding periodics. |
709 | \& \- Queue all outstanding periodics. |
715 | \& - If no events are pending now, queue all idle watchers. |
710 | \& \- If no events are pending now, queue all idle watchers. |
716 | \& - Queue all check watchers. |
711 | \& \- Queue all check watchers. |
717 | \& - Call all queued watchers in reverse order (i.e. check watchers first). |
712 | \& \- Call all queued watchers in reverse order (i.e. check watchers first). |
718 | \& Signals and child watchers are implemented as I/O watchers, and will |
713 | \& Signals and child watchers are implemented as I/O watchers, and will |
719 | \& be handled here by queueing them when their watcher gets executed. |
714 | \& be handled here by queueing them when their watcher gets executed. |
720 | \& - If ev_unloop has been called or EVLOOP_ONESHOT or EVLOOP_NONBLOCK |
715 | \& \- If ev_unloop has been called, or EVLOOP_ONESHOT or EVLOOP_NONBLOCK |
721 | \& were used, return, otherwise continue with step *. |
716 | \& were used, or there are no active watchers, return, otherwise |
|
|
717 | \& continue with step *. |
722 | .Ve |
718 | .Ve |
723 | .Sp |
719 | .Sp |
724 | Example: Queue some jobs and then loop until no events are outsanding |
720 | Example: Queue some jobs and then loop until no events are outstanding |
725 | anymore. |
721 | anymore. |
726 | .Sp |
722 | .Sp |
727 | .Vb 4 |
723 | .Vb 4 |
728 | \& ... queue jobs here, make sure they register event watchers as long |
724 | \& ... queue jobs here, make sure they register event watchers as long |
729 | \& ... as they still have work to do (even an idle watcher will do..) |
725 | \& ... as they still have work to do (even an idle watcher will do..) |
… | |
… | |
734 | .IX Item "ev_unloop (loop, how)" |
730 | .IX Item "ev_unloop (loop, how)" |
735 | Can be used to make a call to \f(CW\*(C`ev_loop\*(C'\fR return early (but only after it |
731 | Can be used to make a call to \f(CW\*(C`ev_loop\*(C'\fR return early (but only after it |
736 | has processed all outstanding events). The \f(CW\*(C`how\*(C'\fR argument must be either |
732 | has processed all outstanding events). The \f(CW\*(C`how\*(C'\fR argument must be either |
737 | \&\f(CW\*(C`EVUNLOOP_ONE\*(C'\fR, which will make the innermost \f(CW\*(C`ev_loop\*(C'\fR call return, or |
733 | \&\f(CW\*(C`EVUNLOOP_ONE\*(C'\fR, which will make the innermost \f(CW\*(C`ev_loop\*(C'\fR call return, or |
738 | \&\f(CW\*(C`EVUNLOOP_ALL\*(C'\fR, which will make all nested \f(CW\*(C`ev_loop\*(C'\fR calls return. |
734 | \&\f(CW\*(C`EVUNLOOP_ALL\*(C'\fR, which will make all nested \f(CW\*(C`ev_loop\*(C'\fR calls return. |
|
|
735 | .Sp |
|
|
736 | This \*(L"unloop state\*(R" will be cleared when entering \f(CW\*(C`ev_loop\*(C'\fR again. |
739 | .IP "ev_ref (loop)" 4 |
737 | .IP "ev_ref (loop)" 4 |
740 | .IX Item "ev_ref (loop)" |
738 | .IX Item "ev_ref (loop)" |
741 | .PD 0 |
739 | .PD 0 |
742 | .IP "ev_unref (loop)" 4 |
740 | .IP "ev_unref (loop)" 4 |
743 | .IX Item "ev_unref (loop)" |
741 | .IX Item "ev_unref (loop)" |
… | |
… | |
749 | returning, \fIev_unref()\fR after starting, and \fIev_ref()\fR before stopping it. For |
747 | returning, \fIev_unref()\fR after starting, and \fIev_ref()\fR before stopping it. For |
750 | example, libev itself uses this for its internal signal pipe: It is not |
748 | example, libev itself uses this for its internal signal pipe: It is not |
751 | visible to the libev user and should not keep \f(CW\*(C`ev_loop\*(C'\fR from exiting if |
749 | visible to the libev user and should not keep \f(CW\*(C`ev_loop\*(C'\fR from exiting if |
752 | no event watchers registered by it are active. It is also an excellent |
750 | no event watchers registered by it are active. It is also an excellent |
753 | way to do this for generic recurring timers or from within third-party |
751 | way to do this for generic recurring timers or from within third-party |
754 | libraries. Just remember to \fIunref after start\fR and \fIref before stop\fR. |
752 | libraries. Just remember to \fIunref after start\fR and \fIref before stop\fR |
|
|
753 | (but only if the watcher wasn't active before, or was active before, |
|
|
754 | respectively). |
755 | .Sp |
755 | .Sp |
756 | Example: Create a signal watcher, but keep it from keeping \f(CW\*(C`ev_loop\*(C'\fR |
756 | Example: Create a signal watcher, but keep it from keeping \f(CW\*(C`ev_loop\*(C'\fR |
757 | running when nothing else is active. |
757 | running when nothing else is active. |
758 | .Sp |
758 | .Sp |
759 | .Vb 4 |
759 | .Vb 4 |
… | |
… | |
816 | \& static void my_cb (struct ev_loop *loop, struct ev_io *w, int revents) |
816 | \& static void my_cb (struct ev_loop *loop, struct ev_io *w, int revents) |
817 | \& { |
817 | \& { |
818 | \& ev_io_stop (w); |
818 | \& ev_io_stop (w); |
819 | \& ev_unloop (loop, EVUNLOOP_ALL); |
819 | \& ev_unloop (loop, EVUNLOOP_ALL); |
820 | \& } |
820 | \& } |
821 | .Ve |
821 | \& |
822 | .PP |
|
|
823 | .Vb 6 |
|
|
824 | \& struct ev_loop *loop = ev_default_loop (0); |
822 | \& struct ev_loop *loop = ev_default_loop (0); |
825 | \& struct ev_io stdin_watcher; |
823 | \& struct ev_io stdin_watcher; |
826 | \& ev_init (&stdin_watcher, my_cb); |
824 | \& ev_init (&stdin_watcher, my_cb); |
827 | \& ev_io_set (&stdin_watcher, STDIN_FILENO, EV_READ); |
825 | \& ev_io_set (&stdin_watcher, STDIN_FILENO, EV_READ); |
828 | \& ev_io_start (loop, &stdin_watcher); |
826 | \& ev_io_start (loop, &stdin_watcher); |
… | |
… | |
1089 | In this case getting the pointer to \f(CW\*(C`my_biggy\*(C'\fR is a bit more complicated, |
1087 | In this case getting the pointer to \f(CW\*(C`my_biggy\*(C'\fR is a bit more complicated, |
1090 | you need to use \f(CW\*(C`offsetof\*(C'\fR: |
1088 | you need to use \f(CW\*(C`offsetof\*(C'\fR: |
1091 | .PP |
1089 | .PP |
1092 | .Vb 1 |
1090 | .Vb 1 |
1093 | \& #include <stddef.h> |
1091 | \& #include <stddef.h> |
1094 | .Ve |
1092 | \& |
1095 | .PP |
|
|
1096 | .Vb 6 |
|
|
1097 | \& static void |
1093 | \& static void |
1098 | \& t1_cb (EV_P_ struct ev_timer *w, int revents) |
1094 | \& t1_cb (EV_P_ struct ev_timer *w, int revents) |
1099 | \& { |
1095 | \& { |
1100 | \& struct my_biggy big = (struct my_biggy * |
1096 | \& struct my_biggy big = (struct my_biggy * |
1101 | \& (((char *)w) - offsetof (struct my_biggy, t1)); |
1097 | \& (((char *)w) \- offsetof (struct my_biggy, t1)); |
1102 | \& } |
1098 | \& } |
1103 | .Ve |
1099 | \& |
1104 | .PP |
|
|
1105 | .Vb 6 |
|
|
1106 | \& static void |
1100 | \& static void |
1107 | \& t2_cb (EV_P_ struct ev_timer *w, int revents) |
1101 | \& t2_cb (EV_P_ struct ev_timer *w, int revents) |
1108 | \& { |
1102 | \& { |
1109 | \& struct my_biggy big = (struct my_biggy * |
1103 | \& struct my_biggy big = (struct my_biggy * |
1110 | \& (((char *)w) - offsetof (struct my_biggy, t2)); |
1104 | \& (((char *)w) \- offsetof (struct my_biggy, t2)); |
1111 | \& } |
1105 | \& } |
1112 | .Ve |
1106 | .Ve |
1113 | .SH "WATCHER TYPES" |
1107 | .SH "WATCHER TYPES" |
1114 | .IX Header "WATCHER TYPES" |
1108 | .IX Header "WATCHER TYPES" |
1115 | This section describes each watcher in detail, but will not repeat |
1109 | This section describes each watcher in detail, but will not repeat |
… | |
… | |
1221 | The file descriptor being watched. |
1215 | The file descriptor being watched. |
1222 | .IP "int events [read\-only]" 4 |
1216 | .IP "int events [read\-only]" 4 |
1223 | .IX Item "int events [read-only]" |
1217 | .IX Item "int events [read-only]" |
1224 | The events being watched. |
1218 | The events being watched. |
1225 | .PP |
1219 | .PP |
|
|
1220 | \fIExamples\fR |
|
|
1221 | .IX Subsection "Examples" |
|
|
1222 | .PP |
1226 | Example: Call \f(CW\*(C`stdin_readable_cb\*(C'\fR when \s-1STDIN_FILENO\s0 has become, well |
1223 | Example: Call \f(CW\*(C`stdin_readable_cb\*(C'\fR when \s-1STDIN_FILENO\s0 has become, well |
1227 | readable, but only once. Since it is likely line\-buffered, you could |
1224 | readable, but only once. Since it is likely line-buffered, you could |
1228 | attempt to read a whole line in the callback. |
1225 | attempt to read a whole line in the callback. |
1229 | .PP |
1226 | .PP |
1230 | .Vb 6 |
1227 | .Vb 6 |
1231 | \& static void |
1228 | \& static void |
1232 | \& stdin_readable_cb (struct ev_loop *loop, struct ev_io *w, int revents) |
1229 | \& stdin_readable_cb (struct ev_loop *loop, struct ev_io *w, int revents) |
1233 | \& { |
1230 | \& { |
1234 | \& ev_io_stop (loop, w); |
1231 | \& ev_io_stop (loop, w); |
1235 | \& .. read from stdin here (or from w->fd) and haqndle any I/O errors |
1232 | \& .. read from stdin here (or from w\->fd) and haqndle any I/O errors |
1236 | \& } |
1233 | \& } |
1237 | .Ve |
1234 | \& |
1238 | .PP |
|
|
1239 | .Vb 6 |
|
|
1240 | \& ... |
1235 | \& ... |
1241 | \& struct ev_loop *loop = ev_default_init (0); |
1236 | \& struct ev_loop *loop = ev_default_init (0); |
1242 | \& struct ev_io stdin_readable; |
1237 | \& struct ev_io stdin_readable; |
1243 | \& ev_io_init (&stdin_readable, stdin_readable_cb, STDIN_FILENO, EV_READ); |
1238 | \& ev_io_init (&stdin_readable, stdin_readable_cb, STDIN_FILENO, EV_READ); |
1244 | \& ev_io_start (loop, &stdin_readable); |
1239 | \& ev_io_start (loop, &stdin_readable); |
… | |
… | |
1261 | of the event triggering whatever timeout you are modifying/starting. If |
1256 | of the event triggering whatever timeout you are modifying/starting. If |
1262 | you suspect event processing to be delayed and you \fIneed\fR to base the timeout |
1257 | you suspect event processing to be delayed and you \fIneed\fR to base the timeout |
1263 | on the current time, use something like this to adjust for this: |
1258 | on the current time, use something like this to adjust for this: |
1264 | .PP |
1259 | .PP |
1265 | .Vb 1 |
1260 | .Vb 1 |
1266 | \& ev_timer_set (&timer, after + ev_now () - ev_time (), 0.); |
1261 | \& ev_timer_set (&timer, after + ev_now () \- ev_time (), 0.); |
1267 | .Ve |
1262 | .Ve |
1268 | .PP |
1263 | .PP |
1269 | The callback is guarenteed to be invoked only when its timeout has passed, |
1264 | The callback is guarenteed to be invoked only when its timeout has passed, |
1270 | but if multiple timers become ready during the same loop iteration then |
1265 | but if multiple timers become ready during the same loop iteration then |
1271 | order of execution is undefined. |
1266 | order of execution is undefined. |
… | |
… | |
1315 | .Sp |
1310 | .Sp |
1316 | .Vb 8 |
1311 | .Vb 8 |
1317 | \& ev_timer_init (timer, callback, 0., 5.); |
1312 | \& ev_timer_init (timer, callback, 0., 5.); |
1318 | \& ev_timer_again (loop, timer); |
1313 | \& ev_timer_again (loop, timer); |
1319 | \& ... |
1314 | \& ... |
1320 | \& timer->again = 17.; |
1315 | \& timer\->again = 17.; |
1321 | \& ev_timer_again (loop, timer); |
1316 | \& ev_timer_again (loop, timer); |
1322 | \& ... |
1317 | \& ... |
1323 | \& timer->again = 10.; |
1318 | \& timer\->again = 10.; |
1324 | \& ev_timer_again (loop, timer); |
1319 | \& ev_timer_again (loop, timer); |
1325 | .Ve |
1320 | .Ve |
1326 | .Sp |
1321 | .Sp |
1327 | This is more slightly efficient then stopping/starting the timer each time |
1322 | This is more slightly efficient then stopping/starting the timer each time |
1328 | you want to modify its timeout value. |
1323 | you want to modify its timeout value. |
… | |
… | |
1330 | .IX Item "ev_tstamp repeat [read-write]" |
1325 | .IX Item "ev_tstamp repeat [read-write]" |
1331 | The current \f(CW\*(C`repeat\*(C'\fR value. Will be used each time the watcher times out |
1326 | The current \f(CW\*(C`repeat\*(C'\fR value. Will be used each time the watcher times out |
1332 | or \f(CW\*(C`ev_timer_again\*(C'\fR is called and determines the next timeout (if any), |
1327 | or \f(CW\*(C`ev_timer_again\*(C'\fR is called and determines the next timeout (if any), |
1333 | which is also when any modifications are taken into account. |
1328 | which is also when any modifications are taken into account. |
1334 | .PP |
1329 | .PP |
|
|
1330 | \fIExamples\fR |
|
|
1331 | .IX Subsection "Examples" |
|
|
1332 | .PP |
1335 | Example: Create a timer that fires after 60 seconds. |
1333 | Example: Create a timer that fires after 60 seconds. |
1336 | .PP |
1334 | .PP |
1337 | .Vb 5 |
1335 | .Vb 5 |
1338 | \& static void |
1336 | \& static void |
1339 | \& one_minute_cb (struct ev_loop *loop, struct ev_timer *w, int revents) |
1337 | \& one_minute_cb (struct ev_loop *loop, struct ev_timer *w, int revents) |
1340 | \& { |
1338 | \& { |
1341 | \& .. one minute over, w is actually stopped right here |
1339 | \& .. one minute over, w is actually stopped right here |
1342 | \& } |
1340 | \& } |
1343 | .Ve |
1341 | \& |
1344 | .PP |
|
|
1345 | .Vb 3 |
|
|
1346 | \& struct ev_timer mytimer; |
1342 | \& struct ev_timer mytimer; |
1347 | \& ev_timer_init (&mytimer, one_minute_cb, 60., 0.); |
1343 | \& ev_timer_init (&mytimer, one_minute_cb, 60., 0.); |
1348 | \& ev_timer_start (loop, &mytimer); |
1344 | \& ev_timer_start (loop, &mytimer); |
1349 | .Ve |
1345 | .Ve |
1350 | .PP |
1346 | .PP |
… | |
… | |
1355 | \& static void |
1351 | \& static void |
1356 | \& timeout_cb (struct ev_loop *loop, struct ev_timer *w, int revents) |
1352 | \& timeout_cb (struct ev_loop *loop, struct ev_timer *w, int revents) |
1357 | \& { |
1353 | \& { |
1358 | \& .. ten seconds without any activity |
1354 | \& .. ten seconds without any activity |
1359 | \& } |
1355 | \& } |
1360 | .Ve |
1356 | \& |
1361 | .PP |
|
|
1362 | .Vb 4 |
|
|
1363 | \& struct ev_timer mytimer; |
1357 | \& struct ev_timer mytimer; |
1364 | \& ev_timer_init (&mytimer, timeout_cb, 0., 10.); /* note, only repeat used */ |
1358 | \& ev_timer_init (&mytimer, timeout_cb, 0., 10.); /* note, only repeat used */ |
1365 | \& ev_timer_again (&mytimer); /* start timer */ |
1359 | \& ev_timer_again (&mytimer); /* start timer */ |
1366 | \& ev_loop (loop, 0); |
1360 | \& ev_loop (loop, 0); |
1367 | .Ve |
1361 | \& |
1368 | .PP |
|
|
1369 | .Vb 3 |
|
|
1370 | \& // and in some piece of code that gets executed on any "activity": |
1362 | \& // and in some piece of code that gets executed on any "activity": |
1371 | \& // reset the timeout to start ticking again at 10 seconds |
1363 | \& // reset the timeout to start ticking again at 10 seconds |
1372 | \& ev_timer_again (&mytimer); |
1364 | \& ev_timer_again (&mytimer); |
1373 | .Ve |
1365 | .Ve |
1374 | .ie n .Sh """ev_periodic"" \- to cron or not to cron?" |
1366 | .ie n .Sh """ev_periodic"" \- to cron or not to cron?" |
… | |
… | |
1402 | .IX Item "ev_periodic_set (ev_periodic *, ev_tstamp after, ev_tstamp repeat, reschedule_cb)" |
1394 | .IX Item "ev_periodic_set (ev_periodic *, ev_tstamp after, ev_tstamp repeat, reschedule_cb)" |
1403 | .PD |
1395 | .PD |
1404 | Lots of arguments, lets sort it out... There are basically three modes of |
1396 | Lots of arguments, lets sort it out... There are basically three modes of |
1405 | operation, and we will explain them from simplest to complex: |
1397 | operation, and we will explain them from simplest to complex: |
1406 | .RS 4 |
1398 | .RS 4 |
|
|
1399 | .IP "\(bu" 4 |
1407 | .IP "* absolute timer (at = time, interval = reschedule_cb = 0)" 4 |
1400 | absolute timer (at = time, interval = reschedule_cb = 0) |
1408 | .IX Item "absolute timer (at = time, interval = reschedule_cb = 0)" |
1401 | .Sp |
1409 | In this configuration the watcher triggers an event at the wallclock time |
1402 | In this configuration the watcher triggers an event at the wallclock time |
1410 | \&\f(CW\*(C`at\*(C'\fR and doesn't repeat. It will not adjust when a time jump occurs, |
1403 | \&\f(CW\*(C`at\*(C'\fR and doesn't repeat. It will not adjust when a time jump occurs, |
1411 | that is, if it is to be run at January 1st 2011 then it will run when the |
1404 | that is, if it is to be run at January 1st 2011 then it will run when the |
1412 | system time reaches or surpasses this time. |
1405 | system time reaches or surpasses this time. |
|
|
1406 | .IP "\(bu" 4 |
1413 | .IP "* non-repeating interval timer (at = offset, interval > 0, reschedule_cb = 0)" 4 |
1407 | non-repeating interval timer (at = offset, interval > 0, reschedule_cb = 0) |
1414 | .IX Item "non-repeating interval timer (at = offset, interval > 0, reschedule_cb = 0)" |
1408 | .Sp |
1415 | In this mode the watcher will always be scheduled to time out at the next |
1409 | In this mode the watcher will always be scheduled to time out at the next |
1416 | \&\f(CW\*(C`at + N * interval\*(C'\fR time (for some integer N, which can also be negative) |
1410 | \&\f(CW\*(C`at + N * interval\*(C'\fR time (for some integer N, which can also be negative) |
1417 | and then repeat, regardless of any time jumps. |
1411 | and then repeat, regardless of any time jumps. |
1418 | .Sp |
1412 | .Sp |
1419 | This can be used to create timers that do not drift with respect to system |
1413 | This can be used to create timers that do not drift with respect to system |
… | |
… | |
1433 | time where \f(CW\*(C`time = at (mod interval)\*(C'\fR, regardless of any time jumps. |
1427 | time where \f(CW\*(C`time = at (mod interval)\*(C'\fR, regardless of any time jumps. |
1434 | .Sp |
1428 | .Sp |
1435 | For numerical stability it is preferable that the \f(CW\*(C`at\*(C'\fR value is near |
1429 | For numerical stability it is preferable that the \f(CW\*(C`at\*(C'\fR value is near |
1436 | \&\f(CW\*(C`ev_now ()\*(C'\fR (the current time), but there is no range requirement for |
1430 | \&\f(CW\*(C`ev_now ()\*(C'\fR (the current time), but there is no range requirement for |
1437 | this value. |
1431 | this value. |
|
|
1432 | .IP "\(bu" 4 |
1438 | .IP "* manual reschedule mode (at and interval ignored, reschedule_cb = callback)" 4 |
1433 | manual reschedule mode (at and interval ignored, reschedule_cb = callback) |
1439 | .IX Item "manual reschedule mode (at and interval ignored, reschedule_cb = callback)" |
1434 | .Sp |
1440 | In this mode the values for \f(CW\*(C`interval\*(C'\fR and \f(CW\*(C`at\*(C'\fR are both being |
1435 | In this mode the values for \f(CW\*(C`interval\*(C'\fR and \f(CW\*(C`at\*(C'\fR are both being |
1441 | ignored. Instead, each time the periodic watcher gets scheduled, the |
1436 | ignored. Instead, each time the periodic watcher gets scheduled, the |
1442 | reschedule callback will be called with the watcher as first, and the |
1437 | reschedule callback will be called with the watcher as first, and the |
1443 | current time as second argument. |
1438 | current time as second argument. |
1444 | .Sp |
1439 | .Sp |
… | |
… | |
1499 | .IP "ev_tstamp at [read\-only]" 4 |
1494 | .IP "ev_tstamp at [read\-only]" 4 |
1500 | .IX Item "ev_tstamp at [read-only]" |
1495 | .IX Item "ev_tstamp at [read-only]" |
1501 | When active, contains the absolute time that the watcher is supposed to |
1496 | When active, contains the absolute time that the watcher is supposed to |
1502 | trigger next. |
1497 | trigger next. |
1503 | .PP |
1498 | .PP |
|
|
1499 | \fIExamples\fR |
|
|
1500 | .IX Subsection "Examples" |
|
|
1501 | .PP |
1504 | Example: Call a callback every hour, or, more precisely, whenever the |
1502 | Example: Call a callback every hour, or, more precisely, whenever the |
1505 | system clock is divisible by 3600. The callback invocation times have |
1503 | system clock is divisible by 3600. The callback invocation times have |
1506 | potentially a lot of jittering, but good long-term stability. |
1504 | potentially a lot of jittering, but good long-term stability. |
1507 | .PP |
1505 | .PP |
1508 | .Vb 5 |
1506 | .Vb 5 |
1509 | \& static void |
1507 | \& static void |
1510 | \& clock_cb (struct ev_loop *loop, struct ev_io *w, int revents) |
1508 | \& clock_cb (struct ev_loop *loop, struct ev_io *w, int revents) |
1511 | \& { |
1509 | \& { |
1512 | \& ... its now a full hour (UTC, or TAI or whatever your clock follows) |
1510 | \& ... its now a full hour (UTC, or TAI or whatever your clock follows) |
1513 | \& } |
1511 | \& } |
1514 | .Ve |
1512 | \& |
1515 | .PP |
|
|
1516 | .Vb 3 |
|
|
1517 | \& struct ev_periodic hourly_tick; |
1513 | \& struct ev_periodic hourly_tick; |
1518 | \& ev_periodic_init (&hourly_tick, clock_cb, 0., 3600., 0); |
1514 | \& ev_periodic_init (&hourly_tick, clock_cb, 0., 3600., 0); |
1519 | \& ev_periodic_start (loop, &hourly_tick); |
1515 | \& ev_periodic_start (loop, &hourly_tick); |
1520 | .Ve |
1516 | .Ve |
1521 | .PP |
1517 | .PP |
1522 | Example: The same as above, but use a reschedule callback to do it: |
1518 | Example: The same as above, but use a reschedule callback to do it: |
1523 | .PP |
1519 | .PP |
1524 | .Vb 1 |
1520 | .Vb 1 |
1525 | \& #include <math.h> |
1521 | \& #include <math.h> |
1526 | .Ve |
1522 | \& |
1527 | .PP |
|
|
1528 | .Vb 5 |
|
|
1529 | \& static ev_tstamp |
1523 | \& static ev_tstamp |
1530 | \& my_scheduler_cb (struct ev_periodic *w, ev_tstamp now) |
1524 | \& my_scheduler_cb (struct ev_periodic *w, ev_tstamp now) |
1531 | \& { |
1525 | \& { |
1532 | \& return fmod (now, 3600.) + 3600.; |
1526 | \& return fmod (now, 3600.) + 3600.; |
1533 | \& } |
1527 | \& } |
1534 | .Ve |
1528 | \& |
1535 | .PP |
|
|
1536 | .Vb 1 |
|
|
1537 | \& ev_periodic_init (&hourly_tick, clock_cb, 0., 0., my_scheduler_cb); |
1529 | \& ev_periodic_init (&hourly_tick, clock_cb, 0., 0., my_scheduler_cb); |
1538 | .Ve |
1530 | .Ve |
1539 | .PP |
1531 | .PP |
1540 | Example: Call a callback every hour, starting now: |
1532 | Example: Call a callback every hour, starting now: |
1541 | .PP |
1533 | .PP |
… | |
… | |
1579 | Child watchers trigger when your process receives a \s-1SIGCHLD\s0 in response to |
1571 | Child watchers trigger when your process receives a \s-1SIGCHLD\s0 in response to |
1580 | some child status changes (most typically when a child of yours dies). |
1572 | some child status changes (most typically when a child of yours dies). |
1581 | .PP |
1573 | .PP |
1582 | \fIWatcher-Specific Functions and Data Members\fR |
1574 | \fIWatcher-Specific Functions and Data Members\fR |
1583 | .IX Subsection "Watcher-Specific Functions and Data Members" |
1575 | .IX Subsection "Watcher-Specific Functions and Data Members" |
1584 | .IP "ev_child_init (ev_child *, callback, int pid)" 4 |
1576 | .IP "ev_child_init (ev_child *, callback, int pid, int trace)" 4 |
1585 | .IX Item "ev_child_init (ev_child *, callback, int pid)" |
1577 | .IX Item "ev_child_init (ev_child *, callback, int pid, int trace)" |
1586 | .PD 0 |
1578 | .PD 0 |
1587 | .IP "ev_child_set (ev_child *, int pid)" 4 |
1579 | .IP "ev_child_set (ev_child *, int pid, int trace)" 4 |
1588 | .IX Item "ev_child_set (ev_child *, int pid)" |
1580 | .IX Item "ev_child_set (ev_child *, int pid, int trace)" |
1589 | .PD |
1581 | .PD |
1590 | Configures the watcher to wait for status changes of process \f(CW\*(C`pid\*(C'\fR (or |
1582 | Configures the watcher to wait for status changes of process \f(CW\*(C`pid\*(C'\fR (or |
1591 | \&\fIany\fR process if \f(CW\*(C`pid\*(C'\fR is specified as \f(CW0\fR). The callback can look |
1583 | \&\fIany\fR process if \f(CW\*(C`pid\*(C'\fR is specified as \f(CW0\fR). The callback can look |
1592 | at the \f(CW\*(C`rstatus\*(C'\fR member of the \f(CW\*(C`ev_child\*(C'\fR watcher structure to see |
1584 | at the \f(CW\*(C`rstatus\*(C'\fR member of the \f(CW\*(C`ev_child\*(C'\fR watcher structure to see |
1593 | the status word (use the macros from \f(CW\*(C`sys/wait.h\*(C'\fR and see your systems |
1585 | the status word (use the macros from \f(CW\*(C`sys/wait.h\*(C'\fR and see your systems |
1594 | \&\f(CW\*(C`waitpid\*(C'\fR documentation). The \f(CW\*(C`rpid\*(C'\fR member contains the pid of the |
1586 | \&\f(CW\*(C`waitpid\*(C'\fR documentation). The \f(CW\*(C`rpid\*(C'\fR member contains the pid of the |
1595 | process causing the status change. |
1587 | process causing the status change. \f(CW\*(C`trace\*(C'\fR must be either \f(CW0\fR (only |
|
|
1588 | activate the watcher when the process terminates) or \f(CW1\fR (additionally |
|
|
1589 | activate the watcher when the process is stopped or continued). |
1596 | .IP "int pid [read\-only]" 4 |
1590 | .IP "int pid [read\-only]" 4 |
1597 | .IX Item "int pid [read-only]" |
1591 | .IX Item "int pid [read-only]" |
1598 | The process id this watcher watches out for, or \f(CW0\fR, meaning any process id. |
1592 | The process id this watcher watches out for, or \f(CW0\fR, meaning any process id. |
1599 | .IP "int rpid [read\-write]" 4 |
1593 | .IP "int rpid [read\-write]" 4 |
1600 | .IX Item "int rpid [read-write]" |
1594 | .IX Item "int rpid [read-write]" |
… | |
… | |
1602 | .IP "int rstatus [read\-write]" 4 |
1596 | .IP "int rstatus [read\-write]" 4 |
1603 | .IX Item "int rstatus [read-write]" |
1597 | .IX Item "int rstatus [read-write]" |
1604 | The process exit/trace status caused by \f(CW\*(C`rpid\*(C'\fR (see your systems |
1598 | The process exit/trace status caused by \f(CW\*(C`rpid\*(C'\fR (see your systems |
1605 | \&\f(CW\*(C`waitpid\*(C'\fR and \f(CW\*(C`sys/wait.h\*(C'\fR documentation for details). |
1599 | \&\f(CW\*(C`waitpid\*(C'\fR and \f(CW\*(C`sys/wait.h\*(C'\fR documentation for details). |
1606 | .PP |
1600 | .PP |
|
|
1601 | \fIExamples\fR |
|
|
1602 | .IX Subsection "Examples" |
|
|
1603 | .PP |
1607 | Example: Try to exit cleanly on \s-1SIGINT\s0 and \s-1SIGTERM\s0. |
1604 | Example: Try to exit cleanly on \s-1SIGINT\s0 and \s-1SIGTERM\s0. |
1608 | .PP |
1605 | .PP |
1609 | .Vb 5 |
1606 | .Vb 5 |
1610 | \& static void |
1607 | \& static void |
1611 | \& sigint_cb (struct ev_loop *loop, struct ev_signal *w, int revents) |
1608 | \& sigint_cb (struct ev_loop *loop, struct ev_signal *w, int revents) |
1612 | \& { |
1609 | \& { |
1613 | \& ev_unloop (loop, EVUNLOOP_ALL); |
1610 | \& ev_unloop (loop, EVUNLOOP_ALL); |
1614 | \& } |
1611 | \& } |
1615 | .Ve |
1612 | \& |
1616 | .PP |
|
|
1617 | .Vb 3 |
|
|
1618 | \& struct ev_signal signal_watcher; |
1613 | \& struct ev_signal signal_watcher; |
1619 | \& ev_signal_init (&signal_watcher, sigint_cb, SIGINT); |
1614 | \& ev_signal_init (&signal_watcher, sigint_cb, SIGINT); |
1620 | \& ev_signal_start (loop, &sigint_cb); |
1615 | \& ev_signal_start (loop, &sigint_cb); |
1621 | .Ve |
1616 | .Ve |
1622 | .ie n .Sh """ev_stat"" \- did the file attributes just change?" |
1617 | .ie n .Sh """ev_stat"" \- did the file attributes just change?" |
… | |
… | |
1644 | impose a minimum interval which is currently around \f(CW0.1\fR, but thats |
1639 | impose a minimum interval which is currently around \f(CW0.1\fR, but thats |
1645 | usually overkill. |
1640 | usually overkill. |
1646 | .PP |
1641 | .PP |
1647 | This watcher type is not meant for massive numbers of stat watchers, |
1642 | This watcher type is not meant for massive numbers of stat watchers, |
1648 | as even with OS-supported change notifications, this can be |
1643 | as even with OS-supported change notifications, this can be |
1649 | resource\-intensive. |
1644 | resource-intensive. |
1650 | .PP |
1645 | .PP |
1651 | At the time of this writing, only the Linux inotify interface is |
1646 | At the time of this writing, only the Linux inotify interface is |
1652 | implemented (implementing kqueue support is left as an exercise for the |
1647 | implemented (implementing kqueue support is left as an exercise for the |
1653 | reader). Inotify will be used to give hints only and should not change the |
1648 | reader). Inotify will be used to give hints only and should not change the |
1654 | semantics of \f(CW\*(C`ev_stat\*(C'\fR watchers, which means that libev sometimes needs |
1649 | semantics of \f(CW\*(C`ev_stat\*(C'\fR watchers, which means that libev sometimes needs |
… | |
… | |
1734 | \fIExamples\fR |
1729 | \fIExamples\fR |
1735 | .IX Subsection "Examples" |
1730 | .IX Subsection "Examples" |
1736 | .PP |
1731 | .PP |
1737 | Example: Watch \f(CW\*(C`/etc/passwd\*(C'\fR for attribute changes. |
1732 | Example: Watch \f(CW\*(C`/etc/passwd\*(C'\fR for attribute changes. |
1738 | .PP |
1733 | .PP |
1739 | .Vb 15 |
1734 | .Vb 10 |
1740 | \& static void |
1735 | \& static void |
1741 | \& passwd_cb (struct ev_loop *loop, ev_stat *w, int revents) |
1736 | \& passwd_cb (struct ev_loop *loop, ev_stat *w, int revents) |
1742 | \& { |
1737 | \& { |
1743 | \& /* /etc/passwd changed in some way */ |
1738 | \& /* /etc/passwd changed in some way */ |
1744 | \& if (w->attr.st_nlink) |
1739 | \& if (w\->attr.st_nlink) |
1745 | \& { |
1740 | \& { |
1746 | \& printf ("passwd current size %ld\en", (long)w->attr.st_size); |
1741 | \& printf ("passwd current size %ld\en", (long)w\->attr.st_size); |
1747 | \& printf ("passwd current atime %ld\en", (long)w->attr.st_mtime); |
1742 | \& printf ("passwd current atime %ld\en", (long)w\->attr.st_mtime); |
1748 | \& printf ("passwd current mtime %ld\en", (long)w->attr.st_mtime); |
1743 | \& printf ("passwd current mtime %ld\en", (long)w\->attr.st_mtime); |
1749 | \& } |
1744 | \& } |
1750 | \& else |
1745 | \& else |
1751 | \& /* you shalt not abuse printf for puts */ |
1746 | \& /* you shalt not abuse printf for puts */ |
1752 | \& puts ("wow, /etc/passwd is not there, expect problems. " |
1747 | \& puts ("wow, /etc/passwd is not there, expect problems. " |
1753 | \& "if this is windows, they already arrived\en"); |
1748 | \& "if this is windows, they already arrived\en"); |
1754 | \& } |
1749 | \& } |
1755 | .Ve |
1750 | \& |
1756 | .PP |
|
|
1757 | .Vb 2 |
|
|
1758 | \& ... |
1751 | \& ... |
1759 | \& ev_stat passwd; |
1752 | \& ev_stat passwd; |
1760 | .Ve |
1753 | \& |
1761 | .PP |
|
|
1762 | .Vb 2 |
|
|
1763 | \& ev_stat_init (&passwd, passwd_cb, "/etc/passwd", 0.); |
1754 | \& ev_stat_init (&passwd, passwd_cb, "/etc/passwd", 0.); |
1764 | \& ev_stat_start (loop, &passwd); |
1755 | \& ev_stat_start (loop, &passwd); |
1765 | .Ve |
1756 | .Ve |
1766 | .PP |
1757 | .PP |
1767 | Example: Like above, but additionally use a one-second delay so we do not |
1758 | Example: Like above, but additionally use a one-second delay so we do not |
… | |
… | |
1770 | \&\f(CW\*(C`ev_timer\*(C'\fR callback invocation). |
1761 | \&\f(CW\*(C`ev_timer\*(C'\fR callback invocation). |
1771 | .PP |
1762 | .PP |
1772 | .Vb 2 |
1763 | .Vb 2 |
1773 | \& static ev_stat passwd; |
1764 | \& static ev_stat passwd; |
1774 | \& static ev_timer timer; |
1765 | \& static ev_timer timer; |
1775 | .Ve |
1766 | \& |
1776 | .PP |
|
|
1777 | .Vb 4 |
|
|
1778 | \& static void |
1767 | \& static void |
1779 | \& timer_cb (EV_P_ ev_timer *w, int revents) |
1768 | \& timer_cb (EV_P_ ev_timer *w, int revents) |
1780 | \& { |
1769 | \& { |
1781 | \& ev_timer_stop (EV_A_ w); |
1770 | \& ev_timer_stop (EV_A_ w); |
1782 | .Ve |
1771 | \& |
1783 | .PP |
|
|
1784 | .Vb 2 |
|
|
1785 | \& /* now it's one second after the most recent passwd change */ |
1772 | \& /* now it\*(Aqs one second after the most recent passwd change */ |
1786 | \& } |
1773 | \& } |
1787 | .Ve |
1774 | \& |
1788 | .PP |
|
|
1789 | .Vb 6 |
|
|
1790 | \& static void |
1775 | \& static void |
1791 | \& stat_cb (EV_P_ ev_stat *w, int revents) |
1776 | \& stat_cb (EV_P_ ev_stat *w, int revents) |
1792 | \& { |
1777 | \& { |
1793 | \& /* reset the one-second timer */ |
1778 | \& /* reset the one\-second timer */ |
1794 | \& ev_timer_again (EV_A_ &timer); |
1779 | \& ev_timer_again (EV_A_ &timer); |
1795 | \& } |
1780 | \& } |
1796 | .Ve |
1781 | \& |
1797 | .PP |
|
|
1798 | .Vb 4 |
|
|
1799 | \& ... |
1782 | \& ... |
1800 | \& ev_stat_init (&passwd, stat_cb, "/etc/passwd", 0.); |
1783 | \& ev_stat_init (&passwd, stat_cb, "/etc/passwd", 0.); |
1801 | \& ev_stat_start (loop, &passwd); |
1784 | \& ev_stat_start (loop, &passwd); |
1802 | \& ev_timer_init (&timer, timer_cb, 0., 1.01); |
1785 | \& ev_timer_init (&timer, timer_cb, 0., 1.01); |
1803 | .Ve |
1786 | .Ve |
… | |
… | |
1818 | The most noteworthy effect is that as long as any idle watchers are |
1801 | The most noteworthy effect is that as long as any idle watchers are |
1819 | active, the process will not block when waiting for new events. |
1802 | active, the process will not block when waiting for new events. |
1820 | .PP |
1803 | .PP |
1821 | Apart from keeping your process non-blocking (which is a useful |
1804 | Apart from keeping your process non-blocking (which is a useful |
1822 | effect on its own sometimes), idle watchers are a good place to do |
1805 | effect on its own sometimes), idle watchers are a good place to do |
1823 | \&\*(L"pseudo\-background processing\*(R", or delay processing stuff to after the |
1806 | \&\*(L"pseudo-background processing\*(R", or delay processing stuff to after the |
1824 | event loop has handled all outstanding events. |
1807 | event loop has handled all outstanding events. |
1825 | .PP |
1808 | .PP |
1826 | \fIWatcher-Specific Functions and Data Members\fR |
1809 | \fIWatcher-Specific Functions and Data Members\fR |
1827 | .IX Subsection "Watcher-Specific Functions and Data Members" |
1810 | .IX Subsection "Watcher-Specific Functions and Data Members" |
1828 | .IP "ev_idle_init (ev_signal *, callback)" 4 |
1811 | .IP "ev_idle_init (ev_signal *, callback)" 4 |
1829 | .IX Item "ev_idle_init (ev_signal *, callback)" |
1812 | .IX Item "ev_idle_init (ev_signal *, callback)" |
1830 | Initialises and configures the idle watcher \- it has no parameters of any |
1813 | Initialises and configures the idle watcher \- it has no parameters of any |
1831 | kind. There is a \f(CW\*(C`ev_idle_set\*(C'\fR macro, but using it is utterly pointless, |
1814 | kind. There is a \f(CW\*(C`ev_idle_set\*(C'\fR macro, but using it is utterly pointless, |
1832 | believe me. |
1815 | believe me. |
1833 | .PP |
1816 | .PP |
|
|
1817 | \fIExamples\fR |
|
|
1818 | .IX Subsection "Examples" |
|
|
1819 | .PP |
1834 | Example: Dynamically allocate an \f(CW\*(C`ev_idle\*(C'\fR watcher, start it, and in the |
1820 | Example: Dynamically allocate an \f(CW\*(C`ev_idle\*(C'\fR watcher, start it, and in the |
1835 | callback, free it. Also, use no error checking, as usual. |
1821 | callback, free it. Also, use no error checking, as usual. |
1836 | .PP |
1822 | .PP |
1837 | .Vb 7 |
1823 | .Vb 7 |
1838 | \& static void |
1824 | \& static void |
1839 | \& idle_cb (struct ev_loop *loop, struct ev_idle *w, int revents) |
1825 | \& idle_cb (struct ev_loop *loop, struct ev_idle *w, int revents) |
1840 | \& { |
1826 | \& { |
1841 | \& free (w); |
1827 | \& free (w); |
1842 | \& // now do something you wanted to do when the program has |
1828 | \& // now do something you wanted to do when the program has |
1843 | \& // no longer asnything immediate to do. |
1829 | \& // no longer anything immediate to do. |
1844 | \& } |
1830 | \& } |
1845 | .Ve |
1831 | \& |
1846 | .PP |
|
|
1847 | .Vb 3 |
|
|
1848 | \& struct ev_idle *idle_watcher = malloc (sizeof (struct ev_idle)); |
1832 | \& struct ev_idle *idle_watcher = malloc (sizeof (struct ev_idle)); |
1849 | \& ev_idle_init (idle_watcher, idle_cb); |
1833 | \& ev_idle_init (idle_watcher, idle_cb); |
1850 | \& ev_idle_start (loop, idle_cb); |
1834 | \& ev_idle_start (loop, idle_cb); |
1851 | .Ve |
1835 | .Ve |
1852 | .ie n .Sh """ev_prepare""\fP and \f(CW""ev_check"" \- customise your event loop!" |
1836 | .ie n .Sh """ev_prepare""\fP and \f(CW""ev_check"" \- customise your event loop!" |
… | |
… | |
1894 | priority, to ensure that they are being run before any other watchers |
1878 | priority, to ensure that they are being run before any other watchers |
1895 | after the poll. Also, \f(CW\*(C`ev_check\*(C'\fR watchers (and \f(CW\*(C`ev_prepare\*(C'\fR watchers, |
1879 | after the poll. Also, \f(CW\*(C`ev_check\*(C'\fR watchers (and \f(CW\*(C`ev_prepare\*(C'\fR watchers, |
1896 | too) should not activate (\*(L"feed\*(R") events into libev. While libev fully |
1880 | too) should not activate (\*(L"feed\*(R") events into libev. While libev fully |
1897 | supports this, they will be called before other \f(CW\*(C`ev_check\*(C'\fR watchers |
1881 | supports this, they will be called before other \f(CW\*(C`ev_check\*(C'\fR watchers |
1898 | did their job. As \f(CW\*(C`ev_check\*(C'\fR watchers are often used to embed other |
1882 | did their job. As \f(CW\*(C`ev_check\*(C'\fR watchers are often used to embed other |
1899 | (non\-libev) event loops those other event loops might be in an unusable |
1883 | (non-libev) event loops those other event loops might be in an unusable |
1900 | state until their \f(CW\*(C`ev_check\*(C'\fR watcher ran (always remind yourself to |
1884 | state until their \f(CW\*(C`ev_check\*(C'\fR watcher ran (always remind yourself to |
1901 | coexist peacefully with others). |
1885 | coexist peacefully with others). |
1902 | .PP |
1886 | .PP |
1903 | \fIWatcher-Specific Functions and Data Members\fR |
1887 | \fIWatcher-Specific Functions and Data Members\fR |
1904 | .IX Subsection "Watcher-Specific Functions and Data Members" |
1888 | .IX Subsection "Watcher-Specific Functions and Data Members" |
… | |
… | |
1910 | .PD |
1894 | .PD |
1911 | Initialises and configures the prepare or check watcher \- they have no |
1895 | Initialises and configures the prepare or check watcher \- they have no |
1912 | parameters of any kind. There are \f(CW\*(C`ev_prepare_set\*(C'\fR and \f(CW\*(C`ev_check_set\*(C'\fR |
1896 | parameters of any kind. There are \f(CW\*(C`ev_prepare_set\*(C'\fR and \f(CW\*(C`ev_check_set\*(C'\fR |
1913 | macros, but using them is utterly, utterly and completely pointless. |
1897 | macros, but using them is utterly, utterly and completely pointless. |
1914 | .PP |
1898 | .PP |
|
|
1899 | \fIExamples\fR |
|
|
1900 | .IX Subsection "Examples" |
|
|
1901 | .PP |
1915 | There are a number of principal ways to embed other event loops or modules |
1902 | There are a number of principal ways to embed other event loops or modules |
1916 | into libev. Here are some ideas on how to include libadns into libev |
1903 | into libev. Here are some ideas on how to include libadns into libev |
1917 | (there is a Perl module named \f(CW\*(C`EV::ADNS\*(C'\fR that does this, which you could |
1904 | (there is a Perl module named \f(CW\*(C`EV::ADNS\*(C'\fR that does this, which you could |
1918 | use for an actually working example. Another Perl module named \f(CW\*(C`EV::Glib\*(C'\fR |
1905 | use for an actually working example. Another Perl module named \f(CW\*(C`EV::Glib\*(C'\fR |
1919 | embeds a Glib main context into libev, and finally, \f(CW\*(C`Glib::EV\*(C'\fR embeds \s-1EV\s0 |
1906 | embeds a Glib main context into libev, and finally, \f(CW\*(C`Glib::EV\*(C'\fR embeds \s-1EV\s0 |
… | |
… | |
1926 | the callbacks for the IO/timeout watchers might not have been called yet. |
1913 | the callbacks for the IO/timeout watchers might not have been called yet. |
1927 | .PP |
1914 | .PP |
1928 | .Vb 2 |
1915 | .Vb 2 |
1929 | \& static ev_io iow [nfd]; |
1916 | \& static ev_io iow [nfd]; |
1930 | \& static ev_timer tw; |
1917 | \& static ev_timer tw; |
1931 | .Ve |
1918 | \& |
1932 | .PP |
|
|
1933 | .Vb 4 |
|
|
1934 | \& static void |
1919 | \& static void |
1935 | \& io_cb (ev_loop *loop, ev_io *w, int revents) |
1920 | \& io_cb (ev_loop *loop, ev_io *w, int revents) |
1936 | \& { |
1921 | \& { |
1937 | \& } |
1922 | \& } |
1938 | .Ve |
1923 | \& |
1939 | .PP |
|
|
1940 | .Vb 8 |
|
|
1941 | \& // create io watchers for each fd and a timer before blocking |
1924 | \& // create io watchers for each fd and a timer before blocking |
1942 | \& static void |
1925 | \& static void |
1943 | \& adns_prepare_cb (ev_loop *loop, ev_prepare *w, int revents) |
1926 | \& adns_prepare_cb (ev_loop *loop, ev_prepare *w, int revents) |
1944 | \& { |
1927 | \& { |
1945 | \& int timeout = 3600000; |
1928 | \& int timeout = 3600000; |
1946 | \& struct pollfd fds [nfd]; |
1929 | \& struct pollfd fds [nfd]; |
1947 | \& // actual code will need to loop here and realloc etc. |
1930 | \& // actual code will need to loop here and realloc etc. |
1948 | \& adns_beforepoll (ads, fds, &nfd, &timeout, timeval_from (ev_time ())); |
1931 | \& adns_beforepoll (ads, fds, &nfd, &timeout, timeval_from (ev_time ())); |
1949 | .Ve |
1932 | \& |
1950 | .PP |
|
|
1951 | .Vb 3 |
|
|
1952 | \& /* the callback is illegal, but won't be called as we stop during check */ |
1933 | \& /* the callback is illegal, but won\*(Aqt be called as we stop during check */ |
1953 | \& ev_timer_init (&tw, 0, timeout * 1e-3); |
1934 | \& ev_timer_init (&tw, 0, timeout * 1e\-3); |
1954 | \& ev_timer_start (loop, &tw); |
1935 | \& ev_timer_start (loop, &tw); |
1955 | .Ve |
1936 | \& |
1956 | .PP |
|
|
1957 | .Vb 6 |
|
|
1958 | \& // create one ev_io per pollfd |
1937 | \& // create one ev_io per pollfd |
1959 | \& for (int i = 0; i < nfd; ++i) |
1938 | \& for (int i = 0; i < nfd; ++i) |
1960 | \& { |
1939 | \& { |
1961 | \& ev_io_init (iow + i, io_cb, fds [i].fd, |
1940 | \& ev_io_init (iow + i, io_cb, fds [i].fd, |
1962 | \& ((fds [i].events & POLLIN ? EV_READ : 0) |
1941 | \& ((fds [i].events & POLLIN ? EV_READ : 0) |
1963 | \& | (fds [i].events & POLLOUT ? EV_WRITE : 0))); |
1942 | \& | (fds [i].events & POLLOUT ? EV_WRITE : 0))); |
1964 | .Ve |
1943 | \& |
1965 | .PP |
|
|
1966 | .Vb 4 |
|
|
1967 | \& fds [i].revents = 0; |
1944 | \& fds [i].revents = 0; |
1968 | \& ev_io_start (loop, iow + i); |
1945 | \& ev_io_start (loop, iow + i); |
1969 | \& } |
1946 | \& } |
1970 | \& } |
1947 | \& } |
1971 | .Ve |
1948 | \& |
1972 | .PP |
|
|
1973 | .Vb 5 |
|
|
1974 | \& // stop all watchers after blocking |
1949 | \& // stop all watchers after blocking |
1975 | \& static void |
1950 | \& static void |
1976 | \& adns_check_cb (ev_loop *loop, ev_check *w, int revents) |
1951 | \& adns_check_cb (ev_loop *loop, ev_check *w, int revents) |
1977 | \& { |
1952 | \& { |
1978 | \& ev_timer_stop (loop, &tw); |
1953 | \& ev_timer_stop (loop, &tw); |
1979 | .Ve |
1954 | \& |
1980 | .PP |
|
|
1981 | .Vb 8 |
|
|
1982 | \& for (int i = 0; i < nfd; ++i) |
1955 | \& for (int i = 0; i < nfd; ++i) |
1983 | \& { |
1956 | \& { |
1984 | \& // set the relevant poll flags |
1957 | \& // set the relevant poll flags |
1985 | \& // could also call adns_processreadable etc. here |
1958 | \& // could also call adns_processreadable etc. here |
1986 | \& struct pollfd *fd = fds + i; |
1959 | \& struct pollfd *fd = fds + i; |
1987 | \& int revents = ev_clear_pending (iow + i); |
1960 | \& int revents = ev_clear_pending (iow + i); |
1988 | \& if (revents & EV_READ ) fd->revents |= fd->events & POLLIN; |
1961 | \& if (revents & EV_READ ) fd\->revents |= fd\->events & POLLIN; |
1989 | \& if (revents & EV_WRITE) fd->revents |= fd->events & POLLOUT; |
1962 | \& if (revents & EV_WRITE) fd\->revents |= fd\->events & POLLOUT; |
1990 | .Ve |
1963 | \& |
1991 | .PP |
|
|
1992 | .Vb 3 |
|
|
1993 | \& // now stop the watcher |
1964 | \& // now stop the watcher |
1994 | \& ev_io_stop (loop, iow + i); |
1965 | \& ev_io_stop (loop, iow + i); |
1995 | \& } |
1966 | \& } |
1996 | .Ve |
1967 | \& |
1997 | .PP |
|
|
1998 | .Vb 2 |
|
|
1999 | \& adns_afterpoll (adns, fds, nfd, timeval_from (ev_now (loop)); |
1968 | \& adns_afterpoll (adns, fds, nfd, timeval_from (ev_now (loop)); |
2000 | \& } |
1969 | \& } |
2001 | .Ve |
1970 | .Ve |
2002 | .PP |
1971 | .PP |
2003 | Method 2: This would be just like method 1, but you run \f(CW\*(C`adns_afterpoll\*(C'\fR |
1972 | Method 2: This would be just like method 1, but you run \f(CW\*(C`adns_afterpoll\*(C'\fR |
… | |
… | |
2009 | .PP |
1978 | .PP |
2010 | .Vb 5 |
1979 | .Vb 5 |
2011 | \& static void |
1980 | \& static void |
2012 | \& timer_cb (EV_P_ ev_timer *w, int revents) |
1981 | \& timer_cb (EV_P_ ev_timer *w, int revents) |
2013 | \& { |
1982 | \& { |
2014 | \& adns_state ads = (adns_state)w->data; |
1983 | \& adns_state ads = (adns_state)w\->data; |
2015 | \& update_now (EV_A); |
1984 | \& update_now (EV_A); |
2016 | .Ve |
1985 | \& |
2017 | .PP |
|
|
2018 | .Vb 2 |
|
|
2019 | \& adns_processtimeouts (ads, &tv_now); |
1986 | \& adns_processtimeouts (ads, &tv_now); |
2020 | \& } |
1987 | \& } |
2021 | .Ve |
1988 | \& |
2022 | .PP |
|
|
2023 | .Vb 5 |
|
|
2024 | \& static void |
1989 | \& static void |
2025 | \& io_cb (EV_P_ ev_io *w, int revents) |
1990 | \& io_cb (EV_P_ ev_io *w, int revents) |
2026 | \& { |
1991 | \& { |
2027 | \& adns_state ads = (adns_state)w->data; |
1992 | \& adns_state ads = (adns_state)w\->data; |
2028 | \& update_now (EV_A); |
1993 | \& update_now (EV_A); |
2029 | .Ve |
1994 | \& |
2030 | .PP |
|
|
2031 | .Vb 3 |
|
|
2032 | \& if (revents & EV_READ ) adns_processreadable (ads, w->fd, &tv_now); |
1995 | \& if (revents & EV_READ ) adns_processreadable (ads, w\->fd, &tv_now); |
2033 | \& if (revents & EV_WRITE) adns_processwriteable (ads, w->fd, &tv_now); |
1996 | \& if (revents & EV_WRITE) adns_processwriteable (ads, w\->fd, &tv_now); |
2034 | \& } |
1997 | \& } |
2035 | .Ve |
1998 | \& |
2036 | .PP |
|
|
2037 | .Vb 1 |
|
|
2038 | \& // do not ever call adns_afterpoll |
1999 | \& // do not ever call adns_afterpoll |
2039 | .Ve |
2000 | .Ve |
2040 | .PP |
2001 | .PP |
2041 | Method 4: Do not use a prepare or check watcher because the module you |
2002 | Method 4: Do not use a prepare or check watcher because the module you |
2042 | want to embed is too inflexible to support it. Instead, youc na override |
2003 | want to embed is too inflexible to support it. Instead, youc na override |
… | |
… | |
2047 | .Vb 4 |
2008 | .Vb 4 |
2048 | \& static gint |
2009 | \& static gint |
2049 | \& event_poll_func (GPollFD *fds, guint nfds, gint timeout) |
2010 | \& event_poll_func (GPollFD *fds, guint nfds, gint timeout) |
2050 | \& { |
2011 | \& { |
2051 | \& int got_events = 0; |
2012 | \& int got_events = 0; |
2052 | .Ve |
2013 | \& |
2053 | .PP |
|
|
2054 | .Vb 2 |
|
|
2055 | \& for (n = 0; n < nfds; ++n) |
2014 | \& for (n = 0; n < nfds; ++n) |
2056 | \& // create/start io watcher that sets the relevant bits in fds[n] and increment got_events |
2015 | \& // create/start io watcher that sets the relevant bits in fds[n] and increment got_events |
2057 | .Ve |
2016 | \& |
2058 | .PP |
|
|
2059 | .Vb 2 |
|
|
2060 | \& if (timeout >= 0) |
2017 | \& if (timeout >= 0) |
2061 | \& // create/start timer |
2018 | \& // create/start timer |
2062 | .Ve |
2019 | \& |
2063 | .PP |
|
|
2064 | .Vb 2 |
|
|
2065 | \& // poll |
2020 | \& // poll |
2066 | \& ev_loop (EV_A_ 0); |
2021 | \& ev_loop (EV_A_ 0); |
2067 | .Ve |
2022 | \& |
2068 | .PP |
|
|
2069 | .Vb 3 |
|
|
2070 | \& // stop timer again |
2023 | \& // stop timer again |
2071 | \& if (timeout >= 0) |
2024 | \& if (timeout >= 0) |
2072 | \& ev_timer_stop (EV_A_ &to); |
2025 | \& ev_timer_stop (EV_A_ &to); |
2073 | .Ve |
2026 | \& |
2074 | .PP |
|
|
2075 | .Vb 3 |
|
|
2076 | \& // stop io watchers again - their callbacks should have set |
2027 | \& // stop io watchers again \- their callbacks should have set |
2077 | \& for (n = 0; n < nfds; ++n) |
2028 | \& for (n = 0; n < nfds; ++n) |
2078 | \& ev_io_stop (EV_A_ iow [n]); |
2029 | \& ev_io_stop (EV_A_ iow [n]); |
2079 | .Ve |
2030 | \& |
2080 | .PP |
|
|
2081 | .Vb 2 |
|
|
2082 | \& return got_events; |
2031 | \& return got_events; |
2083 | \& } |
2032 | \& } |
2084 | .Ve |
2033 | .Ve |
2085 | .ie n .Sh """ev_embed"" \- when one backend isn't enough..." |
2034 | .ie n .Sh """ev_embed"" \- when one backend isn't enough..." |
2086 | .el .Sh "\f(CWev_embed\fP \- when one backend isn't enough..." |
2035 | .el .Sh "\f(CWev_embed\fP \- when one backend isn't enough..." |
… | |
… | |
2130 | portable one. |
2079 | portable one. |
2131 | .PP |
2080 | .PP |
2132 | So when you want to use this feature you will always have to be prepared |
2081 | So when you want to use this feature you will always have to be prepared |
2133 | that you cannot get an embeddable loop. The recommended way to get around |
2082 | that you cannot get an embeddable loop. The recommended way to get around |
2134 | this is to have a separate variables for your embeddable loop, try to |
2083 | this is to have a separate variables for your embeddable loop, try to |
2135 | create it, and if that fails, use the normal loop for everything: |
2084 | create it, and if that fails, use the normal loop for everything. |
2136 | .PP |
|
|
2137 | .Vb 3 |
|
|
2138 | \& struct ev_loop *loop_hi = ev_default_init (0); |
|
|
2139 | \& struct ev_loop *loop_lo = 0; |
|
|
2140 | \& struct ev_embed embed; |
|
|
2141 | .Ve |
|
|
2142 | .PP |
|
|
2143 | .Vb 5 |
|
|
2144 | \& // see if there is a chance of getting one that works |
|
|
2145 | \& // (remember that a flags value of 0 means autodetection) |
|
|
2146 | \& loop_lo = ev_embeddable_backends () & ev_recommended_backends () |
|
|
2147 | \& ? ev_loop_new (ev_embeddable_backends () & ev_recommended_backends ()) |
|
|
2148 | \& : 0; |
|
|
2149 | .Ve |
|
|
2150 | .PP |
|
|
2151 | .Vb 8 |
|
|
2152 | \& // if we got one, then embed it, otherwise default to loop_hi |
|
|
2153 | \& if (loop_lo) |
|
|
2154 | \& { |
|
|
2155 | \& ev_embed_init (&embed, 0, loop_lo); |
|
|
2156 | \& ev_embed_start (loop_hi, &embed); |
|
|
2157 | \& } |
|
|
2158 | \& else |
|
|
2159 | \& loop_lo = loop_hi; |
|
|
2160 | .Ve |
|
|
2161 | .PP |
2085 | .PP |
2162 | \fIWatcher-Specific Functions and Data Members\fR |
2086 | \fIWatcher-Specific Functions and Data Members\fR |
2163 | .IX Subsection "Watcher-Specific Functions and Data Members" |
2087 | .IX Subsection "Watcher-Specific Functions and Data Members" |
2164 | .IP "ev_embed_init (ev_embed *, callback, struct ev_loop *embedded_loop)" 4 |
2088 | .IP "ev_embed_init (ev_embed *, callback, struct ev_loop *embedded_loop)" 4 |
2165 | .IX Item "ev_embed_init (ev_embed *, callback, struct ev_loop *embedded_loop)" |
2089 | .IX Item "ev_embed_init (ev_embed *, callback, struct ev_loop *embedded_loop)" |
… | |
… | |
2178 | similarly to \f(CW\*(C`ev_loop (embedded_loop, EVLOOP_NONBLOCK)\*(C'\fR, but in the most |
2102 | similarly to \f(CW\*(C`ev_loop (embedded_loop, EVLOOP_NONBLOCK)\*(C'\fR, but in the most |
2179 | apropriate way for embedded loops. |
2103 | apropriate way for embedded loops. |
2180 | .IP "struct ev_loop *other [read\-only]" 4 |
2104 | .IP "struct ev_loop *other [read\-only]" 4 |
2181 | .IX Item "struct ev_loop *other [read-only]" |
2105 | .IX Item "struct ev_loop *other [read-only]" |
2182 | The embedded event loop. |
2106 | The embedded event loop. |
|
|
2107 | .PP |
|
|
2108 | \fIExamples\fR |
|
|
2109 | .IX Subsection "Examples" |
|
|
2110 | .PP |
|
|
2111 | Example: Try to get an embeddable event loop and embed it into the default |
|
|
2112 | event loop. If that is not possible, use the default loop. The default |
|
|
2113 | loop is stored in \f(CW\*(C`loop_hi\*(C'\fR, while the mebeddable loop is stored in |
|
|
2114 | \&\f(CW\*(C`loop_lo\*(C'\fR (which is \f(CW\*(C`loop_hi\*(C'\fR in the acse no embeddable loop can be |
|
|
2115 | used). |
|
|
2116 | .PP |
|
|
2117 | .Vb 3 |
|
|
2118 | \& struct ev_loop *loop_hi = ev_default_init (0); |
|
|
2119 | \& struct ev_loop *loop_lo = 0; |
|
|
2120 | \& struct ev_embed embed; |
|
|
2121 | \& |
|
|
2122 | \& // see if there is a chance of getting one that works |
|
|
2123 | \& // (remember that a flags value of 0 means autodetection) |
|
|
2124 | \& loop_lo = ev_embeddable_backends () & ev_recommended_backends () |
|
|
2125 | \& ? ev_loop_new (ev_embeddable_backends () & ev_recommended_backends ()) |
|
|
2126 | \& : 0; |
|
|
2127 | \& |
|
|
2128 | \& // if we got one, then embed it, otherwise default to loop_hi |
|
|
2129 | \& if (loop_lo) |
|
|
2130 | \& { |
|
|
2131 | \& ev_embed_init (&embed, 0, loop_lo); |
|
|
2132 | \& ev_embed_start (loop_hi, &embed); |
|
|
2133 | \& } |
|
|
2134 | \& else |
|
|
2135 | \& loop_lo = loop_hi; |
|
|
2136 | .Ve |
|
|
2137 | .PP |
|
|
2138 | Example: Check if kqueue is available but not recommended and create |
|
|
2139 | a kqueue backend for use with sockets (which usually work with any |
|
|
2140 | kqueue implementation). Store the kqueue/socket\-only event loop in |
|
|
2141 | \&\f(CW\*(C`loop_socket\*(C'\fR. (One might optionally use \f(CW\*(C`EVFLAG_NOENV\*(C'\fR, too). |
|
|
2142 | .PP |
|
|
2143 | .Vb 3 |
|
|
2144 | \& struct ev_loop *loop = ev_default_init (0); |
|
|
2145 | \& struct ev_loop *loop_socket = 0; |
|
|
2146 | \& struct ev_embed embed; |
|
|
2147 | \& |
|
|
2148 | \& if (ev_supported_backends () & ~ev_recommended_backends () & EVBACKEND_KQUEUE) |
|
|
2149 | \& if ((loop_socket = ev_loop_new (EVBACKEND_KQUEUE)) |
|
|
2150 | \& { |
|
|
2151 | \& ev_embed_init (&embed, 0, loop_socket); |
|
|
2152 | \& ev_embed_start (loop, &embed); |
|
|
2153 | \& } |
|
|
2154 | \& |
|
|
2155 | \& if (!loop_socket) |
|
|
2156 | \& loop_socket = loop; |
|
|
2157 | \& |
|
|
2158 | \& // now use loop_socket for all sockets, and loop for everything else |
|
|
2159 | .Ve |
2183 | .ie n .Sh """ev_fork"" \- the audacity to resume the event loop after a fork" |
2160 | .ie n .Sh """ev_fork"" \- the audacity to resume the event loop after a fork" |
2184 | .el .Sh "\f(CWev_fork\fP \- the audacity to resume the event loop after a fork" |
2161 | .el .Sh "\f(CWev_fork\fP \- the audacity to resume the event loop after a fork" |
2185 | .IX Subsection "ev_fork - the audacity to resume the event loop after a fork" |
2162 | .IX Subsection "ev_fork - the audacity to resume the event loop after a fork" |
2186 | Fork watchers are called when a \f(CW\*(C`fork ()\*(C'\fR was detected (usually because |
2163 | Fork watchers are called when a \f(CW\*(C`fork ()\*(C'\fR was detected (usually because |
2187 | whoever is a good citizen cared to tell libev about it by calling |
2164 | whoever is a good citizen cared to tell libev about it by calling |
… | |
… | |
2229 | \& if (revents & EV_TIMEOUT) |
2206 | \& if (revents & EV_TIMEOUT) |
2230 | \& /* doh, nothing entered */; |
2207 | \& /* doh, nothing entered */; |
2231 | \& else if (revents & EV_READ) |
2208 | \& else if (revents & EV_READ) |
2232 | \& /* stdin might have data for us, joy! */; |
2209 | \& /* stdin might have data for us, joy! */; |
2233 | \& } |
2210 | \& } |
2234 | .Ve |
2211 | \& |
2235 | .Sp |
|
|
2236 | .Vb 1 |
|
|
2237 | \& ev_once (STDIN_FILENO, EV_READ, 10., stdin_ready, 0); |
2212 | \& ev_once (STDIN_FILENO, EV_READ, 10., stdin_ready, 0); |
2238 | .Ve |
2213 | .Ve |
2239 | .IP "ev_feed_event (ev_loop *, watcher *, int revents)" 4 |
2214 | .IP "ev_feed_event (ev_loop *, watcher *, int revents)" 4 |
2240 | .IX Item "ev_feed_event (ev_loop *, watcher *, int revents)" |
2215 | .IX Item "ev_feed_event (ev_loop *, watcher *, int revents)" |
2241 | Feeds the given event set into the event loop, as if the specified event |
2216 | Feeds the given event set into the event loop, as if the specified event |
… | |
… | |
2251 | loop!). |
2226 | loop!). |
2252 | .SH "LIBEVENT EMULATION" |
2227 | .SH "LIBEVENT EMULATION" |
2253 | .IX Header "LIBEVENT EMULATION" |
2228 | .IX Header "LIBEVENT EMULATION" |
2254 | Libev offers a compatibility emulation layer for libevent. It cannot |
2229 | Libev offers a compatibility emulation layer for libevent. It cannot |
2255 | emulate the internals of libevent, so here are some usage hints: |
2230 | emulate the internals of libevent, so here are some usage hints: |
|
|
2231 | .IP "\(bu" 4 |
2256 | .IP "* Use it by including <event.h>, as usual." 4 |
2232 | Use it by including <event.h>, as usual. |
2257 | .IX Item "Use it by including <event.h>, as usual." |
2233 | .IP "\(bu" 4 |
2258 | .PD 0 |
2234 | The following members are fully supported: ev_base, ev_callback, |
2259 | .IP "* The following members are fully supported: ev_base, ev_callback, ev_arg, ev_fd, ev_res, ev_events." 4 |
2235 | ev_arg, ev_fd, ev_res, ev_events. |
2260 | .IX Item "The following members are fully supported: ev_base, ev_callback, ev_arg, ev_fd, ev_res, ev_events." |
2236 | .IP "\(bu" 4 |
2261 | .IP "* Avoid using ev_flags and the EVLIST_*\-macros, while it is maintained by libev, it does not work exactly the same way as in libevent (consider it a private \s-1API\s0)." 4 |
2237 | Avoid using ev_flags and the EVLIST_*\-macros, while it is |
2262 | .IX Item "Avoid using ev_flags and the EVLIST_*-macros, while it is maintained by libev, it does not work exactly the same way as in libevent (consider it a private API)." |
2238 | maintained by libev, it does not work exactly the same way as in libevent (consider |
2263 | .IP "* Priorities are not currently supported. Initialising priorities will fail and all watchers will have the same priority, even though there is an ev_pri field." 4 |
2239 | it a private \s-1API\s0). |
2264 | .IX Item "Priorities are not currently supported. Initialising priorities will fail and all watchers will have the same priority, even though there is an ev_pri field." |
2240 | .IP "\(bu" 4 |
|
|
2241 | Priorities are not currently supported. Initialising priorities |
|
|
2242 | will fail and all watchers will have the same priority, even though there |
|
|
2243 | is an ev_pri field. |
|
|
2244 | .IP "\(bu" 4 |
2265 | .IP "* Other members are not supported." 4 |
2245 | Other members are not supported. |
2266 | .IX Item "Other members are not supported." |
2246 | .IP "\(bu" 4 |
2267 | .IP "* The libev emulation is \fInot\fR \s-1ABI\s0 compatible to libevent, you need to use the libev header file and library." 4 |
2247 | The libev emulation is \fInot\fR \s-1ABI\s0 compatible to libevent, you need |
2268 | .IX Item "The libev emulation is not ABI compatible to libevent, you need to use the libev header file and library." |
2248 | to use the libev header file and library. |
2269 | .PD |
|
|
2270 | .SH "\*(C+ SUPPORT" |
2249 | .SH "\*(C+ SUPPORT" |
2271 | .IX Header " SUPPORT" |
2250 | .IX Header " SUPPORT" |
2272 | Libev comes with some simplistic wrapper classes for \*(C+ that mainly allow |
2251 | Libev comes with some simplistic wrapper classes for \*(C+ that mainly allow |
2273 | you to use some convinience methods to start/stop watchers and also change |
2252 | you to use some convinience methods to start/stop watchers and also change |
2274 | the callback model to a model using method callbacks on objects. |
2253 | the callback model to a model using method callbacks on objects. |
… | |
… | |
2354 | .Vb 4 |
2333 | .Vb 4 |
2355 | \& struct myclass |
2334 | \& struct myclass |
2356 | \& { |
2335 | \& { |
2357 | \& void io_cb (ev::io &w, int revents) { } |
2336 | \& void io_cb (ev::io &w, int revents) { } |
2358 | \& } |
2337 | \& } |
2359 | .Ve |
2338 | \& |
2360 | .Sp |
|
|
2361 | .Vb 3 |
|
|
2362 | \& myclass obj; |
2339 | \& myclass obj; |
2363 | \& ev::io iow; |
2340 | \& ev::io iow; |
2364 | \& iow.set <myclass, &myclass::io_cb> (&obj); |
2341 | \& iow.set <myclass, &myclass::io_cb> (&obj); |
2365 | .Ve |
2342 | .Ve |
2366 | .IP "w\->set<function> (void *data = 0)" 4 |
2343 | .IP "w\->set<function> (void *data = 0)" 4 |
… | |
… | |
2417 | the constructor. |
2394 | the constructor. |
2418 | .PP |
2395 | .PP |
2419 | .Vb 4 |
2396 | .Vb 4 |
2420 | \& class myclass |
2397 | \& class myclass |
2421 | \& { |
2398 | \& { |
2422 | \& ev_io io; void io_cb (ev::io &w, int revents); |
2399 | \& ev::io io; void io_cb (ev::io &w, int revents); |
2423 | \& ev_idle idle void idle_cb (ev::idle &w, int revents); |
2400 | \& ev:idle idle void idle_cb (ev::idle &w, int revents); |
2424 | .Ve |
2401 | \& |
2425 | .PP |
|
|
2426 | .Vb 2 |
|
|
2427 | \& myclass (); |
2402 | \& myclass (int fd) |
2428 | \& } |
|
|
2429 | .Ve |
|
|
2430 | .PP |
|
|
2431 | .Vb 4 |
|
|
2432 | \& myclass::myclass (int fd) |
|
|
2433 | \& { |
2403 | \& { |
2434 | \& io .set <myclass, &myclass::io_cb > (this); |
2404 | \& io .set <myclass, &myclass::io_cb > (this); |
2435 | \& idle.set <myclass, &myclass::idle_cb> (this); |
2405 | \& idle.set <myclass, &myclass::idle_cb> (this); |
2436 | .Ve |
2406 | \& |
2437 | .PP |
|
|
2438 | .Vb 2 |
|
|
2439 | \& io.start (fd, ev::READ); |
2407 | \& io.start (fd, ev::READ); |
|
|
2408 | \& } |
2440 | \& } |
2409 | \& }; |
2441 | .Ve |
2410 | .Ve |
2442 | .SH "MACRO MAGIC" |
2411 | .SH "MACRO MAGIC" |
2443 | .IX Header "MACRO MAGIC" |
2412 | .IX Header "MACRO MAGIC" |
2444 | Libev can be compiled with a variety of options, the most fundamantal |
2413 | Libev can be compiled with a variety of options, the most fundamantal |
2445 | of which is \f(CW\*(C`EV_MULTIPLICITY\*(C'\fR. This option determines whether (most) |
2414 | of which is \f(CW\*(C`EV_MULTIPLICITY\*(C'\fR. This option determines whether (most) |
… | |
… | |
2470 | \&\f(CW\*(C`EV_P_\*(C'\fR is used when other parameters are following. Example: |
2439 | \&\f(CW\*(C`EV_P_\*(C'\fR is used when other parameters are following. Example: |
2471 | .Sp |
2440 | .Sp |
2472 | .Vb 2 |
2441 | .Vb 2 |
2473 | \& // this is how ev_unref is being declared |
2442 | \& // this is how ev_unref is being declared |
2474 | \& static void ev_unref (EV_P); |
2443 | \& static void ev_unref (EV_P); |
2475 | .Ve |
2444 | \& |
2476 | .Sp |
|
|
2477 | .Vb 2 |
|
|
2478 | \& // this is how you can declare your typical callback |
2445 | \& // this is how you can declare your typical callback |
2479 | \& static void cb (EV_P_ ev_timer *w, int revents) |
2446 | \& static void cb (EV_P_ ev_timer *w, int revents) |
2480 | .Ve |
2447 | .Ve |
2481 | .Sp |
2448 | .Sp |
2482 | It declares a parameter \f(CW\*(C`loop\*(C'\fR of type \f(CW\*(C`struct ev_loop *\*(C'\fR, quite |
2449 | It declares a parameter \f(CW\*(C`loop\*(C'\fR of type \f(CW\*(C`struct ev_loop *\*(C'\fR, quite |
… | |
… | |
2495 | \& static void |
2462 | \& static void |
2496 | \& check_cb (EV_P_ ev_timer *w, int revents) |
2463 | \& check_cb (EV_P_ ev_timer *w, int revents) |
2497 | \& { |
2464 | \& { |
2498 | \& ev_check_stop (EV_A_ w); |
2465 | \& ev_check_stop (EV_A_ w); |
2499 | \& } |
2466 | \& } |
2500 | .Ve |
2467 | \& |
2501 | .PP |
|
|
2502 | .Vb 4 |
|
|
2503 | \& ev_check check; |
2468 | \& ev_check check; |
2504 | \& ev_check_init (&check, check_cb); |
2469 | \& ev_check_init (&check, check_cb); |
2505 | \& ev_check_start (EV_DEFAULT_ &check); |
2470 | \& ev_check_start (EV_DEFAULT_ &check); |
2506 | \& ev_loop (EV_DEFAULT_ 0); |
2471 | \& ev_loop (EV_DEFAULT_ 0); |
2507 | .Ve |
2472 | .Ve |
2508 | .SH "EMBEDDING" |
2473 | .SH "EMBEDDING" |
2509 | .IX Header "EMBEDDING" |
2474 | .IX Header "EMBEDDING" |
2510 | Libev can (and often is) directly embedded into host |
2475 | Libev can (and often is) directly embedded into host |
2511 | applications. Examples of applications that embed it include the Deliantra |
2476 | applications. Examples of applications that embed it include the Deliantra |
2512 | Game Server, the \s-1EV\s0 perl module, the \s-1GNU\s0 Virtual Private Ethernet (gvpe) |
2477 | Game Server, the \s-1EV\s0 perl module, the \s-1GNU\s0 Virtual Private Ethernet (gvpe) |
2513 | and rxvt\-unicode. |
2478 | and rxvt-unicode. |
2514 | .PP |
2479 | .PP |
2515 | The goal is to enable you to just copy the necessary files into your |
2480 | The goal is to enable you to just copy the necessary files into your |
2516 | source directory without having to change even a single line in them, so |
2481 | source directory without having to change even a single line in them, so |
2517 | you can easily upgrade by simply copying (or having a checked-out copy of |
2482 | you can easily upgrade by simply copying (or having a checked-out copy of |
2518 | libev somewhere in your source tree). |
2483 | libev somewhere in your source tree). |
… | |
… | |
2553 | .Vb 4 |
2518 | .Vb 4 |
2554 | \& ev.h |
2519 | \& ev.h |
2555 | \& ev.c |
2520 | \& ev.c |
2556 | \& ev_vars.h |
2521 | \& ev_vars.h |
2557 | \& ev_wrap.h |
2522 | \& ev_wrap.h |
2558 | .Ve |
2523 | \& |
2559 | .PP |
|
|
2560 | .Vb 1 |
|
|
2561 | \& ev_win32.c required on win32 platforms only |
2524 | \& ev_win32.c required on win32 platforms only |
2562 | .Ve |
2525 | \& |
2563 | .PP |
|
|
2564 | .Vb 5 |
|
|
2565 | \& ev_select.c only when select backend is enabled (which is enabled by default) |
2526 | \& ev_select.c only when select backend is enabled (which is enabled by default) |
2566 | \& ev_poll.c only when poll backend is enabled (disabled by default) |
2527 | \& ev_poll.c only when poll backend is enabled (disabled by default) |
2567 | \& ev_epoll.c only when the epoll backend is enabled (disabled by default) |
2528 | \& ev_epoll.c only when the epoll backend is enabled (disabled by default) |
2568 | \& ev_kqueue.c only when the kqueue backend is enabled (disabled by default) |
2529 | \& ev_kqueue.c only when the kqueue backend is enabled (disabled by default) |
2569 | \& ev_port.c only when the solaris port backend is enabled (disabled by default) |
2530 | \& ev_port.c only when the solaris port backend is enabled (disabled by default) |
… | |
… | |
2664 | wants osf handles on win32 (this is the case when the select to |
2625 | wants osf handles on win32 (this is the case when the select to |
2665 | be used is the winsock select). This means that it will call |
2626 | be used is the winsock select). This means that it will call |
2666 | \&\f(CW\*(C`_get_osfhandle\*(C'\fR on the fd to convert it to an \s-1OS\s0 handle. Otherwise, |
2627 | \&\f(CW\*(C`_get_osfhandle\*(C'\fR on the fd to convert it to an \s-1OS\s0 handle. Otherwise, |
2667 | it is assumed that all these functions actually work on fds, even |
2628 | it is assumed that all these functions actually work on fds, even |
2668 | on win32. Should not be defined on non\-win32 platforms. |
2629 | on win32. Should not be defined on non\-win32 platforms. |
|
|
2630 | .IP "\s-1EV_FD_TO_WIN32_HANDLE\s0" 4 |
|
|
2631 | .IX Item "EV_FD_TO_WIN32_HANDLE" |
|
|
2632 | If \f(CW\*(C`EV_SELECT_IS_WINSOCKET\*(C'\fR is enabled, then libev needs a way to map |
|
|
2633 | file descriptors to socket handles. When not defining this symbol (the |
|
|
2634 | default), then libev will call \f(CW\*(C`_get_osfhandle\*(C'\fR, which is usually |
|
|
2635 | correct. In some cases, programs use their own file descriptor management, |
|
|
2636 | in which case they can provide this function to map fds to socket handles. |
2669 | .IP "\s-1EV_USE_POLL\s0" 4 |
2637 | .IP "\s-1EV_USE_POLL\s0" 4 |
2670 | .IX Item "EV_USE_POLL" |
2638 | .IX Item "EV_USE_POLL" |
2671 | If defined to be \f(CW1\fR, libev will compile in support for the \f(CW\*(C`poll\*(C'\fR(2) |
2639 | If defined to be \f(CW1\fR, libev will compile in support for the \f(CW\*(C`poll\*(C'\fR(2) |
2672 | backend. Otherwise it will be enabled on non\-win32 platforms. It |
2640 | backend. Otherwise it will be enabled on non\-win32 platforms. It |
2673 | takes precedence over select. |
2641 | takes precedence over select. |
… | |
… | |
2703 | interface to speed up \f(CW\*(C`ev_stat\*(C'\fR watchers. Its actual availability will |
2671 | interface to speed up \f(CW\*(C`ev_stat\*(C'\fR watchers. Its actual availability will |
2704 | be detected at runtime. |
2672 | be detected at runtime. |
2705 | .IP "\s-1EV_H\s0" 4 |
2673 | .IP "\s-1EV_H\s0" 4 |
2706 | .IX Item "EV_H" |
2674 | .IX Item "EV_H" |
2707 | The name of the \fIev.h\fR header file used to include it. The default if |
2675 | The name of the \fIev.h\fR header file used to include it. The default if |
2708 | undefined is \f(CW"ev.h"\fR in \fIevent.h\fR and \fIev.c\fR. This can be used to |
2676 | undefined is \f(CW"ev.h"\fR in \fIevent.h\fR, \fIev.c\fR and \fIev++.h\fR. This can be |
2709 | virtually rename the \fIev.h\fR header file in case of conflicts. |
2677 | used to virtually rename the \fIev.h\fR header file in case of conflicts. |
2710 | .IP "\s-1EV_CONFIG_H\s0" 4 |
2678 | .IP "\s-1EV_CONFIG_H\s0" 4 |
2711 | .IX Item "EV_CONFIG_H" |
2679 | .IX Item "EV_CONFIG_H" |
2712 | If \f(CW\*(C`EV_STANDALONE\*(C'\fR isn't \f(CW1\fR, this variable can be used to override |
2680 | If \f(CW\*(C`EV_STANDALONE\*(C'\fR isn't \f(CW1\fR, this variable can be used to override |
2713 | \&\fIev.c\fR's idea of where to find the \fIconfig.h\fR file, similarly to |
2681 | \&\fIev.c\fR's idea of where to find the \fIconfig.h\fR file, similarly to |
2714 | \&\f(CW\*(C`EV_H\*(C'\fR, above. |
2682 | \&\f(CW\*(C`EV_H\*(C'\fR, above. |
2715 | .IP "\s-1EV_EVENT_H\s0" 4 |
2683 | .IP "\s-1EV_EVENT_H\s0" 4 |
2716 | .IX Item "EV_EVENT_H" |
2684 | .IX Item "EV_EVENT_H" |
2717 | Similarly to \f(CW\*(C`EV_H\*(C'\fR, this macro can be used to override \fIevent.c\fR's idea |
2685 | Similarly to \f(CW\*(C`EV_H\*(C'\fR, this macro can be used to override \fIevent.c\fR's idea |
2718 | of how the \fIevent.h\fR header can be found, the dfeault is \f(CW"event.h"\fR. |
2686 | of how the \fIevent.h\fR header can be found, the default is \f(CW"event.h"\fR. |
2719 | .IP "\s-1EV_PROTOTYPES\s0" 4 |
2687 | .IP "\s-1EV_PROTOTYPES\s0" 4 |
2720 | .IX Item "EV_PROTOTYPES" |
2688 | .IX Item "EV_PROTOTYPES" |
2721 | If defined to be \f(CW0\fR, then \fIev.h\fR will not define any function |
2689 | If defined to be \f(CW0\fR, then \fIev.h\fR will not define any function |
2722 | prototypes, but still define all the structs and other symbols. This is |
2690 | prototypes, but still define all the structs and other symbols. This is |
2723 | occasionally useful if you want to provide your own wrapper functions |
2691 | occasionally useful if you want to provide your own wrapper functions |
… | |
… | |
2818 | .Sh "\s-1EXPORTED\s0 \s-1API\s0 \s-1SYMBOLS\s0" |
2786 | .Sh "\s-1EXPORTED\s0 \s-1API\s0 \s-1SYMBOLS\s0" |
2819 | .IX Subsection "EXPORTED API SYMBOLS" |
2787 | .IX Subsection "EXPORTED API SYMBOLS" |
2820 | If you need to re-export the \s-1API\s0 (e.g. via a dll) and you need a list of |
2788 | If you need to re-export the \s-1API\s0 (e.g. via a dll) and you need a list of |
2821 | exported symbols, you can use the provided \fISymbol.*\fR files which list |
2789 | exported symbols, you can use the provided \fISymbol.*\fR files which list |
2822 | all public symbols, one per line: |
2790 | all public symbols, one per line: |
2823 | .Sp |
2791 | .PP |
2824 | .Vb 2 |
2792 | .Vb 2 |
2825 | \& Symbols.ev for libev proper |
2793 | \& Symbols.ev for libev proper |
2826 | \& Symbols.event for the libevent emulation |
2794 | \& Symbols.event for the libevent emulation |
2827 | .Ve |
2795 | .Ve |
2828 | .Sp |
2796 | .PP |
2829 | This can also be used to rename all public symbols to avoid clashes with |
2797 | This can also be used to rename all public symbols to avoid clashes with |
2830 | multiple versions of libev linked together (which is obviously bad in |
2798 | multiple versions of libev linked together (which is obviously bad in |
2831 | itself, but sometimes it is inconvinient to avoid this). |
2799 | itself, but sometimes it is inconvinient to avoid this). |
2832 | .Sp |
2800 | .PP |
2833 | A sed command like this will create wrapper \f(CW\*(C`#define\*(C'\fR's that you need to |
2801 | A sed command like this will create wrapper \f(CW\*(C`#define\*(C'\fR's that you need to |
2834 | include before including \fIev.h\fR: |
2802 | include before including \fIev.h\fR: |
2835 | .Sp |
2803 | .PP |
2836 | .Vb 1 |
2804 | .Vb 1 |
2837 | \& <Symbols.ev sed -e "s/.*/#define & myprefix_&/" >wrap.h |
2805 | \& <Symbols.ev sed \-e "s/.*/#define & myprefix_&/" >wrap.h |
2838 | .Ve |
2806 | .Ve |
2839 | .Sp |
2807 | .PP |
2840 | This would create a file \fIwrap.h\fR which essentially looks like this: |
2808 | This would create a file \fIwrap.h\fR which essentially looks like this: |
2841 | .Sp |
2809 | .PP |
2842 | .Vb 4 |
2810 | .Vb 4 |
2843 | \& #define ev_backend myprefix_ev_backend |
2811 | \& #define ev_backend myprefix_ev_backend |
2844 | \& #define ev_check_start myprefix_ev_check_start |
2812 | \& #define ev_check_start myprefix_ev_check_start |
2845 | \& #define ev_check_stop myprefix_ev_check_stop |
2813 | \& #define ev_check_stop myprefix_ev_check_stop |
2846 | \& ... |
2814 | \& ... |
… | |
… | |
2852 | (<http://software.schmorp.de/pkg/EV.html>). It has the libev files in |
2820 | (<http://software.schmorp.de/pkg/EV.html>). It has the libev files in |
2853 | the \fIlibev/\fR subdirectory and includes them in the \fI\s-1EV/EVAPI\s0.h\fR (public |
2821 | the \fIlibev/\fR subdirectory and includes them in the \fI\s-1EV/EVAPI\s0.h\fR (public |
2854 | interface) and \fI\s-1EV\s0.xs\fR (implementation) files. Only the \fI\s-1EV\s0.xs\fR file |
2822 | interface) and \fI\s-1EV\s0.xs\fR (implementation) files. Only the \fI\s-1EV\s0.xs\fR file |
2855 | will be compiled. It is pretty complex because it provides its own header |
2823 | will be compiled. It is pretty complex because it provides its own header |
2856 | file. |
2824 | file. |
2857 | .Sp |
2825 | .PP |
2858 | The usage in rxvt-unicode is simpler. It has a \fIev_cpp.h\fR header file |
2826 | The usage in rxvt-unicode is simpler. It has a \fIev_cpp.h\fR header file |
2859 | that everybody includes and which overrides some configure choices: |
2827 | that everybody includes and which overrides some configure choices: |
2860 | .Sp |
2828 | .PP |
2861 | .Vb 9 |
2829 | .Vb 9 |
2862 | \& #define EV_MINIMAL 1 |
2830 | \& #define EV_MINIMAL 1 |
2863 | \& #define EV_USE_POLL 0 |
2831 | \& #define EV_USE_POLL 0 |
2864 | \& #define EV_MULTIPLICITY 0 |
2832 | \& #define EV_MULTIPLICITY 0 |
2865 | \& #define EV_PERIODIC_ENABLE 0 |
2833 | \& #define EV_PERIODIC_ENABLE 0 |
2866 | \& #define EV_STAT_ENABLE 0 |
2834 | \& #define EV_STAT_ENABLE 0 |
2867 | \& #define EV_FORK_ENABLE 0 |
2835 | \& #define EV_FORK_ENABLE 0 |
2868 | \& #define EV_CONFIG_H <config.h> |
2836 | \& #define EV_CONFIG_H <config.h> |
2869 | \& #define EV_MINPRI 0 |
2837 | \& #define EV_MINPRI 0 |
2870 | \& #define EV_MAXPRI 0 |
2838 | \& #define EV_MAXPRI 0 |
2871 | .Ve |
2839 | \& |
2872 | .Sp |
|
|
2873 | .Vb 1 |
|
|
2874 | \& #include "ev++.h" |
2840 | \& #include "ev++.h" |
2875 | .Ve |
2841 | .Ve |
2876 | .Sp |
2842 | .PP |
2877 | And a \fIev_cpp.C\fR implementation file that contains libev proper and is compiled: |
2843 | And a \fIev_cpp.C\fR implementation file that contains libev proper and is compiled: |
2878 | .Sp |
2844 | .PP |
2879 | .Vb 2 |
2845 | .Vb 2 |
2880 | \& #include "ev_cpp.h" |
2846 | \& #include "ev_cpp.h" |
2881 | \& #include "ev.c" |
2847 | \& #include "ev.c" |
2882 | .Ve |
2848 | .Ve |
2883 | .SH "COMPLEXITIES" |
2849 | .SH "COMPLEXITIES" |
2884 | .IX Header "COMPLEXITIES" |
2850 | .IX Header "COMPLEXITIES" |
2885 | In this section the complexities of (many of) the algorithms used inside |
2851 | In this section the complexities of (many of) the algorithms used inside |
2886 | libev will be explained. For complexity discussions about backends see the |
2852 | libev will be explained. For complexity discussions about backends see the |
2887 | documentation for \f(CW\*(C`ev_default_init\*(C'\fR. |
2853 | documentation for \f(CW\*(C`ev_default_init\*(C'\fR. |
2888 | .Sp |
2854 | .PP |
2889 | All of the following are about amortised time: If an array needs to be |
2855 | All of the following are about amortised time: If an array needs to be |
2890 | extended, libev needs to realloc and move the whole array, but this |
2856 | extended, libev needs to realloc and move the whole array, but this |
2891 | happens asymptotically never with higher number of elements, so O(1) might |
2857 | happens asymptotically never with higher number of elements, so O(1) might |
2892 | mean it might do a lengthy realloc operation in rare cases, but on average |
2858 | mean it might do a lengthy realloc operation in rare cases, but on average |
2893 | it is much faster and asymptotically approaches constant time. |
2859 | it is much faster and asymptotically approaches constant time. |
2894 | .RS 4 |
|
|
2895 | .IP "Starting and stopping timer/periodic watchers: O(log skipped_other_timers)" 4 |
2860 | .IP "Starting and stopping timer/periodic watchers: O(log skipped_other_timers)" 4 |
2896 | .IX Item "Starting and stopping timer/periodic watchers: O(log skipped_other_timers)" |
2861 | .IX Item "Starting and stopping timer/periodic watchers: O(log skipped_other_timers)" |
2897 | This means that, when you have a watcher that triggers in one hour and |
2862 | This means that, when you have a watcher that triggers in one hour and |
2898 | there are 100 watchers that would trigger before that then inserting will |
2863 | there are 100 watchers that would trigger before that then inserting will |
2899 | have to skip roughly seven (\f(CW\*(C`ld 100\*(C'\fR) of these watchers. |
2864 | have to skip roughly seven (\f(CW\*(C`ld 100\*(C'\fR) of these watchers. |
… | |
… | |
2930 | .PD |
2895 | .PD |
2931 | Priorities are implemented by allocating some space for each |
2896 | Priorities are implemented by allocating some space for each |
2932 | priority. When doing priority-based operations, libev usually has to |
2897 | priority. When doing priority-based operations, libev usually has to |
2933 | linearly search all the priorities, but starting/stopping and activating |
2898 | linearly search all the priorities, but starting/stopping and activating |
2934 | watchers becomes O(1) w.r.t. prioritiy handling. |
2899 | watchers becomes O(1) w.r.t. prioritiy handling. |
2935 | .RE |
2900 | .SH "Win32 platform limitations and workarounds" |
2936 | .RS 4 |
2901 | .IX Header "Win32 platform limitations and workarounds" |
|
|
2902 | Win32 doesn't support any of the standards (e.g. \s-1POSIX\s0) that libev |
|
|
2903 | requires, and its I/O model is fundamentally incompatible with the \s-1POSIX\s0 |
|
|
2904 | model. Libev still offers limited functionality on this platform in |
|
|
2905 | the form of the \f(CW\*(C`EVBACKEND_SELECT\*(C'\fR backend, and only supports socket |
|
|
2906 | descriptors. This only applies when using Win32 natively, not when using |
|
|
2907 | e.g. cygwin. |
|
|
2908 | .PP |
|
|
2909 | There is no supported compilation method available on windows except |
|
|
2910 | embedding it into other applications. |
|
|
2911 | .PP |
|
|
2912 | Due to the many, low, and arbitrary limits on the win32 platform and the |
|
|
2913 | abysmal performance of winsockets, using a large number of sockets is not |
|
|
2914 | recommended (and not reasonable). If your program needs to use more than |
|
|
2915 | a hundred or so sockets, then likely it needs to use a totally different |
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2916 | implementation for windows, as libev offers the \s-1POSIX\s0 model, which cannot |
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2917 | be implemented efficiently on windows (microsoft monopoly games). |
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2918 | .IP "The winsocket select function" 4 |
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2919 | .IX Item "The winsocket select function" |
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2920 | The winsocket \f(CW\*(C`select\*(C'\fR function doesn't follow \s-1POSIX\s0 in that it requires |
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2921 | socket \fIhandles\fR and not socket \fIfile descriptors\fR. This makes select |
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2922 | very inefficient, and also requires a mapping from file descriptors |
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|
2923 | to socket handles. See the discussion of the \f(CW\*(C`EV_SELECT_USE_FD_SET\*(C'\fR, |
|
|
2924 | \&\f(CW\*(C`EV_SELECT_IS_WINSOCKET\*(C'\fR and \f(CW\*(C`EV_FD_TO_WIN32_HANDLE\*(C'\fR preprocessor |
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|
2925 | symbols for more info. |
|
|
2926 | .Sp |
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2927 | The configuration for a \*(L"naked\*(R" win32 using the microsoft runtime |
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2928 | libraries and raw winsocket select is: |
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|
2929 | .Sp |
|
|
2930 | .Vb 2 |
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|
2931 | \& #define EV_USE_SELECT 1 |
|
|
2932 | \& #define EV_SELECT_IS_WINSOCKET 1 /* forces EV_SELECT_USE_FD_SET, too */ |
|
|
2933 | .Ve |
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|
2934 | .Sp |
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|
2935 | Note that winsockets handling of fd sets is O(n), so you can easily get a |
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2936 | complexity in the O(nA\*^X) range when using win32. |
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2937 | .IP "Limited number of file descriptors" 4 |
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|
2938 | .IX Item "Limited number of file descriptors" |
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|
2939 | Windows has numerous arbitrary (and low) limits on things. Early versions |
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|
2940 | of winsocket's select only supported waiting for a max. of \f(CW64\fR handles |
|
|
2941 | (probably owning to the fact that all windows kernels can only wait for |
|
|
2942 | \&\f(CW64\fR things at the same time internally; microsoft recommends spawning a |
|
|
2943 | chain of threads and wait for 63 handles and the previous thread in each). |
|
|
2944 | .Sp |
|
|
2945 | Newer versions support more handles, but you need to define \f(CW\*(C`FD_SETSIZE\*(C'\fR |
|
|
2946 | to some high number (e.g. \f(CW2048\fR) before compiling the winsocket select |
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2947 | call (which might be in libev or elsewhere, for example, perl does its own |
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|
2948 | select emulation on windows). |
|
|
2949 | .Sp |
|
|
2950 | Another limit is the number of file descriptors in the microsoft runtime |
|
|
2951 | libraries, which by default is \f(CW64\fR (there must be a hidden \fI64\fR fetish |
|
|
2952 | or something like this inside microsoft). You can increase this by calling |
|
|
2953 | \&\f(CW\*(C`_setmaxstdio\*(C'\fR, which can increase this limit to \f(CW2048\fR (another |
|
|
2954 | arbitrary limit), but is broken in many versions of the microsoft runtime |
|
|
2955 | libraries. |
|
|
2956 | .Sp |
|
|
2957 | This might get you to about \f(CW512\fR or \f(CW2048\fR sockets (depending on |
|
|
2958 | windows version and/or the phase of the moon). To get more, you need to |
|
|
2959 | wrap all I/O functions and provide your own fd management, but the cost of |
|
|
2960 | calling select (O(nA\*^X)) will likely make this unworkable. |
2937 | .SH "AUTHOR" |
2961 | .SH "AUTHOR" |
2938 | .IX Header "AUTHOR" |
2962 | .IX Header "AUTHOR" |
2939 | Marc Lehmann <libev@schmorp.de>. |
2963 | Marc Lehmann <libev@schmorp.de>. |
|
|
2964 | .SH "POD ERRORS" |
|
|
2965 | .IX Header "POD ERRORS" |
|
|
2966 | Hey! \fBThe above document had some coding errors, which are explained below:\fR |
|
|
2967 | .IP "Around line 2686:" 4 |
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|
2968 | .IX Item "Around line 2686:" |
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|
2969 | You forgot a '=back' before '=head2' |