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4 | <head> |
4 | <head> |
5 | <title>libev</title> |
5 | <title>libev</title> |
6 | <meta name="description" content="Pod documentation for libev" /> |
6 | <meta name="description" content="Pod documentation for libev" /> |
7 | <meta name="inputfile" content="<standard input>" /> |
7 | <meta name="inputfile" content="<standard input>" /> |
8 | <meta name="outputfile" content="<standard output>" /> |
8 | <meta name="outputfile" content="<standard output>" /> |
9 | <meta name="created" content="Fri Nov 23 16:26:06 2007" /> |
9 | <meta name="created" content="Fri Nov 23 17:17:04 2007" /> |
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12 | <body> |
12 | <body> |
13 | <div class="pod"> |
13 | <div class="pod"> |
14 | <!-- INDEX START --> |
14 | <!-- INDEX START --> |
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96 | <div id="TIME_REPRESENTATION_CONTENT"> |
96 | <div id="TIME_REPRESENTATION_CONTENT"> |
97 | <p>Libev represents time as a single floating point number, representing the |
97 | <p>Libev represents time as a single floating point number, representing the |
98 | (fractional) number of seconds since the (POSIX) epoch (somewhere near |
98 | (fractional) number of seconds since the (POSIX) epoch (somewhere near |
99 | the beginning of 1970, details are complicated, don't ask). This type is |
99 | the beginning of 1970, details are complicated, don't ask). This type is |
100 | called <code>ev_tstamp</code>, which is what you should use too. It usually aliases |
100 | called <code>ev_tstamp</code>, which is what you should use too. It usually aliases |
101 | to the double type in C.</p> |
101 | to the <code>double</code> type in C, and when you need to do any calculations on |
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102 | it, you should treat it as such.</p> |
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103 | |
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104 | |
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105 | |
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106 | |
102 | |
107 | |
103 | </div> |
108 | </div> |
104 | <h1 id="GLOBAL_FUNCTIONS">GLOBAL FUNCTIONS</h1><p><a href="#TOP" class="toplink">Top</a></p> |
109 | <h1 id="GLOBAL_FUNCTIONS">GLOBAL FUNCTIONS</h1><p><a href="#TOP" class="toplink">Top</a></p> |
105 | <div id="GLOBAL_FUNCTIONS_CONTENT"> |
110 | <div id="GLOBAL_FUNCTIONS_CONTENT"> |
106 | <p>These functions can be called anytime, even before initialising the |
111 | <p>These functions can be called anytime, even before initialising the |
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122 | version of the library your program was compiled against.</p> |
127 | version of the library your program was compiled against.</p> |
123 | <p>Usually, it's a good idea to terminate if the major versions mismatch, |
128 | <p>Usually, it's a good idea to terminate if the major versions mismatch, |
124 | as this indicates an incompatible change. Minor versions are usually |
129 | as this indicates an incompatible change. Minor versions are usually |
125 | compatible to older versions, so a larger minor version alone is usually |
130 | compatible to older versions, so a larger minor version alone is usually |
126 | not a problem.</p> |
131 | not a problem.</p> |
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132 | <p>Example: make sure we haven't accidentally been linked against the wrong |
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133 | version:</p> |
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134 | <pre> assert (("libev version mismatch", |
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135 | ev_version_major () == EV_VERSION_MAJOR |
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136 | && ev_version_minor () >= EV_VERSION_MINOR)); |
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137 | |
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138 | </pre> |
127 | </dd> |
139 | </dd> |
128 | <dt>unsigned int ev_supported_backends ()</dt> |
140 | <dt>unsigned int ev_supported_backends ()</dt> |
129 | <dd> |
141 | <dd> |
130 | <p>Return the set of all backends (i.e. their corresponding <code>EV_BACKEND_*</code> |
142 | <p>Return the set of all backends (i.e. their corresponding <code>EV_BACKEND_*</code> |
131 | value) compiled into this binary of libev (independent of their |
143 | value) compiled into this binary of libev (independent of their |
132 | availability on the system you are running on). See <code>ev_default_loop</code> for |
144 | availability on the system you are running on). See <code>ev_default_loop</code> for |
133 | a description of the set values.</p> |
145 | a description of the set values.</p> |
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146 | <p>Example: make sure we have the epoll method, because yeah this is cool and |
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147 | a must have and can we have a torrent of it please!!!11</p> |
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148 | <pre> assert (("sorry, no epoll, no sex", |
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149 | ev_supported_backends () & EVBACKEND_EPOLL)); |
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150 | |
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151 | </pre> |
134 | </dd> |
152 | </dd> |
135 | <dt>unsigned int ev_recommended_backends ()</dt> |
153 | <dt>unsigned int ev_recommended_backends ()</dt> |
136 | <dd> |
154 | <dd> |
137 | <p>Return the set of all backends compiled into this binary of libev and also |
155 | <p>Return the set of all backends compiled into this binary of libev and also |
138 | recommended for this platform. This set is often smaller than the one |
156 | recommended for this platform. This set is often smaller than the one |
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149 | needs to be allocated, the library might abort or take some potentially |
167 | needs to be allocated, the library might abort or take some potentially |
150 | destructive action. The default is your system realloc function.</p> |
168 | destructive action. The default is your system realloc function.</p> |
151 | <p>You could override this function in high-availability programs to, say, |
169 | <p>You could override this function in high-availability programs to, say, |
152 | free some memory if it cannot allocate memory, to use a special allocator, |
170 | free some memory if it cannot allocate memory, to use a special allocator, |
153 | or even to sleep a while and retry until some memory is available.</p> |
171 | or even to sleep a while and retry until some memory is available.</p> |
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172 | <p>Example: replace the libev allocator with one that waits a bit and then |
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173 | retries: better than mine).</p> |
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174 | <pre> static void * |
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175 | persistent_realloc (void *ptr, long size) |
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176 | { |
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177 | for (;;) |
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178 | { |
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179 | void *newptr = realloc (ptr, size); |
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180 | |
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181 | if (newptr) |
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182 | return newptr; |
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183 | |
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184 | sleep (60); |
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185 | } |
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186 | } |
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187 | |
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188 | ... |
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189 | ev_set_allocator (persistent_realloc); |
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190 | |
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191 | </pre> |
154 | </dd> |
192 | </dd> |
155 | <dt>ev_set_syserr_cb (void (*cb)(const char *msg));</dt> |
193 | <dt>ev_set_syserr_cb (void (*cb)(const char *msg));</dt> |
156 | <dd> |
194 | <dd> |
157 | <p>Set the callback function to call on a retryable syscall error (such |
195 | <p>Set the callback function to call on a retryable syscall error (such |
158 | as failed select, poll, epoll_wait). The message is a printable string |
196 | as failed select, poll, epoll_wait). The message is a printable string |
159 | indicating the system call or subsystem causing the problem. If this |
197 | indicating the system call or subsystem causing the problem. If this |
160 | callback is set, then libev will expect it to remedy the sitution, no |
198 | callback is set, then libev will expect it to remedy the sitution, no |
161 | matter what, when it returns. That is, libev will generally retry the |
199 | matter what, when it returns. That is, libev will generally retry the |
162 | requested operation, or, if the condition doesn't go away, do bad stuff |
200 | requested operation, or, if the condition doesn't go away, do bad stuff |
163 | (such as abort).</p> |
201 | (such as abort).</p> |
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202 | <p>Example: do the same thing as libev does internally:</p> |
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203 | <pre> static void |
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204 | fatal_error (const char *msg) |
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205 | { |
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206 | perror (msg); |
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207 | abort (); |
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208 | } |
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209 | |
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210 | ... |
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211 | ev_set_syserr_cb (fatal_error); |
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212 | |
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213 | </pre> |
164 | </dd> |
214 | </dd> |
165 | </dl> |
215 | </dl> |
166 | |
216 | |
167 | </div> |
217 | </div> |
168 | <h1 id="FUNCTIONS_CONTROLLING_THE_EVENT_LOOP">FUNCTIONS CONTROLLING THE EVENT LOOP</h1><p><a href="#TOP" class="toplink">Top</a></p> |
218 | <h1 id="FUNCTIONS_CONTROLLING_THE_EVENT_LOOP">FUNCTIONS CONTROLLING THE EVENT LOOP</h1><p><a href="#TOP" class="toplink">Top</a></p> |
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293 | <dd> |
343 | <dd> |
294 | <p>Similar to <code>ev_default_loop</code>, but always creates a new event loop that is |
344 | <p>Similar to <code>ev_default_loop</code>, but always creates a new event loop that is |
295 | always distinct from the default loop. Unlike the default loop, it cannot |
345 | always distinct from the default loop. Unlike the default loop, it cannot |
296 | handle signal and child watchers, and attempts to do so will be greeted by |
346 | handle signal and child watchers, and attempts to do so will be greeted by |
297 | undefined behaviour (or a failed assertion if assertions are enabled).</p> |
347 | undefined behaviour (or a failed assertion if assertions are enabled).</p> |
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348 | <p>Example: try to create a event loop that uses epoll and nothing else.</p> |
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349 | <pre> struct ev_loop *epoller = ev_loop_new (EVBACKEND_EPOLL | EVFLAG_NOENV); |
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350 | if (!epoller) |
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351 | fatal ("no epoll found here, maybe it hides under your chair"); |
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352 | |
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353 | </pre> |
298 | </dd> |
354 | </dd> |
299 | <dt>ev_default_destroy ()</dt> |
355 | <dt>ev_default_destroy ()</dt> |
300 | <dd> |
356 | <dd> |
301 | <p>Destroys the default loop again (frees all memory and kernel state |
357 | <p>Destroys the default loop again (frees all memory and kernel state |
302 | etc.). This stops all registered event watchers (by not touching them in |
358 | etc.). This stops all registered event watchers (by not touching them in |
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338 | use.</p> |
394 | use.</p> |
339 | </dd> |
395 | </dd> |
340 | <dt>ev_tstamp ev_now (loop)</dt> |
396 | <dt>ev_tstamp ev_now (loop)</dt> |
341 | <dd> |
397 | <dd> |
342 | <p>Returns the current "event loop time", which is the time the event loop |
398 | <p>Returns the current "event loop time", which is the time the event loop |
343 | got events and started processing them. This timestamp does not change |
399 | received events and started processing them. This timestamp does not |
344 | as long as callbacks are being processed, and this is also the base time |
400 | change as long as callbacks are being processed, and this is also the base |
345 | used for relative timers. You can treat it as the timestamp of the event |
401 | time used for relative timers. You can treat it as the timestamp of the |
346 | occuring (or more correctly, the mainloop finding out about it).</p> |
402 | event occuring (or more correctly, libev finding out about it).</p> |
347 | </dd> |
403 | </dd> |
348 | <dt>ev_loop (loop, int flags)</dt> |
404 | <dt>ev_loop (loop, int flags)</dt> |
349 | <dd> |
405 | <dd> |
350 | <p>Finally, this is it, the event handler. This function usually is called |
406 | <p>Finally, this is it, the event handler. This function usually is called |
351 | after you initialised all your watchers and you want to start handling |
407 | after you initialised all your watchers and you want to start handling |
352 | events.</p> |
408 | events.</p> |
353 | <p>If the flags argument is specified as <code>0</code>, it will not return until |
409 | <p>If the flags argument is specified as <code>0</code>, it will not return until |
354 | either no event watchers are active anymore or <code>ev_unloop</code> was called.</p> |
410 | either no event watchers are active anymore or <code>ev_unloop</code> was called.</p> |
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411 | <p>Please note that an explicit <code>ev_unloop</code> is usually better than |
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412 | relying on all watchers to be stopped when deciding when a program has |
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413 | finished (especially in interactive programs), but having a program that |
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414 | automatically loops as long as it has to and no longer by virtue of |
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415 | relying on its watchers stopping correctly is a thing of beauty.</p> |
355 | <p>A flags value of <code>EVLOOP_NONBLOCK</code> will look for new events, will handle |
416 | <p>A flags value of <code>EVLOOP_NONBLOCK</code> will look for new events, will handle |
356 | those events and any outstanding ones, but will not block your process in |
417 | those events and any outstanding ones, but will not block your process in |
357 | case there are no events and will return after one iteration of the loop.</p> |
418 | case there are no events and will return after one iteration of the loop.</p> |
358 | <p>A flags value of <code>EVLOOP_ONESHOT</code> will look for new events (waiting if |
419 | <p>A flags value of <code>EVLOOP_ONESHOT</code> will look for new events (waiting if |
359 | neccessary) and will handle those and any outstanding ones. It will block |
420 | neccessary) and will handle those and any outstanding ones. It will block |
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381 | be handled here by queueing them when their watcher gets executed. |
442 | be handled here by queueing them when their watcher gets executed. |
382 | - If ev_unloop has been called or EVLOOP_ONESHOT or EVLOOP_NONBLOCK |
443 | - If ev_unloop has been called or EVLOOP_ONESHOT or EVLOOP_NONBLOCK |
383 | were used, return, otherwise continue with step *. |
444 | were used, return, otherwise continue with step *. |
384 | |
445 | |
385 | </pre> |
446 | </pre> |
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447 | <p>Example: queue some jobs and then loop until no events are outsanding |
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448 | anymore.</p> |
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449 | <pre> ... queue jobs here, make sure they register event watchers as long |
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450 | ... as they still have work to do (even an idle watcher will do..) |
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451 | ev_loop (my_loop, 0); |
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452 | ... jobs done. yeah! |
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453 | |
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454 | </pre> |
386 | </dd> |
455 | </dd> |
387 | <dt>ev_unloop (loop, how)</dt> |
456 | <dt>ev_unloop (loop, how)</dt> |
388 | <dd> |
457 | <dd> |
389 | <p>Can be used to make a call to <code>ev_loop</code> return early (but only after it |
458 | <p>Can be used to make a call to <code>ev_loop</code> return early (but only after it |
390 | has processed all outstanding events). The <code>how</code> argument must be either |
459 | has processed all outstanding events). The <code>how</code> argument must be either |
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402 | example, libev itself uses this for its internal signal pipe: It is not |
471 | example, libev itself uses this for its internal signal pipe: It is not |
403 | visible to the libev user and should not keep <code>ev_loop</code> from exiting if |
472 | visible to the libev user and should not keep <code>ev_loop</code> from exiting if |
404 | no event watchers registered by it are active. It is also an excellent |
473 | no event watchers registered by it are active. It is also an excellent |
405 | way to do this for generic recurring timers or from within third-party |
474 | way to do this for generic recurring timers or from within third-party |
406 | libraries. Just remember to <i>unref after start</i> and <i>ref before stop</i>.</p> |
475 | libraries. Just remember to <i>unref after start</i> and <i>ref before stop</i>.</p> |
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476 | <p>Example: create a signal watcher, but keep it from keeping <code>ev_loop</code> |
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477 | running when nothing else is active.</p> |
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478 | <pre> struct dv_signal exitsig; |
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479 | ev_signal_init (&exitsig, sig_cb, SIGINT); |
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480 | ev_signal_start (myloop, &exitsig); |
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481 | evf_unref (myloop); |
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482 | |
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483 | </pre> |
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484 | <p>Example: for some weird reason, unregister the above signal handler again.</p> |
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485 | <pre> ev_ref (myloop); |
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486 | ev_signal_stop (myloop, &exitsig); |
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487 | |
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488 | </pre> |
407 | </dd> |
489 | </dd> |
408 | </dl> |
490 | </dl> |
409 | |
491 | |
410 | </div> |
492 | </div> |
411 | <h1 id="ANATOMY_OF_A_WATCHER">ANATOMY OF A WATCHER</h1><p><a href="#TOP" class="toplink">Top</a></p> |
493 | <h1 id="ANATOMY_OF_A_WATCHER">ANATOMY OF A WATCHER</h1><p><a href="#TOP" class="toplink">Top</a></p> |
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547 | <h1 id="WATCHER_TYPES">WATCHER TYPES</h1><p><a href="#TOP" class="toplink">Top</a></p> |
629 | <h1 id="WATCHER_TYPES">WATCHER TYPES</h1><p><a href="#TOP" class="toplink">Top</a></p> |
548 | <div id="WATCHER_TYPES_CONTENT"> |
630 | <div id="WATCHER_TYPES_CONTENT"> |
549 | <p>This section describes each watcher in detail, but will not repeat |
631 | <p>This section describes each watcher in detail, but will not repeat |
550 | information given in the last section.</p> |
632 | information given in the last section.</p> |
551 | |
633 | |
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634 | |
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635 | |
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636 | |
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637 | |
552 | </div> |
638 | </div> |
553 | <h2 id="code_ev_io_code_is_this_file_descrip"><code>ev_io</code> - is this file descriptor readable or writable</h2> |
639 | <h2 id="code_ev_io_code_is_this_file_descrip"><code>ev_io</code> - is this file descriptor readable or writable</h2> |
554 | <div id="code_ev_io_code_is_this_file_descrip-2"> |
640 | <div id="code_ev_io_code_is_this_file_descrip-2"> |
555 | <p>I/O watchers check whether a file descriptor is readable or writable |
641 | <p>I/O watchers check whether a file descriptor is readable or writable |
556 | in each iteration of the event loop (This behaviour is called |
642 | in each iteration of the event loop (This behaviour is called |
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586 | when the readyness condition is no longer valid even when employing |
672 | when the readyness condition is no longer valid even when employing |
587 | typical ways of handling events, so its a good idea to use non-blocking |
673 | typical ways of handling events, so its a good idea to use non-blocking |
588 | I/O unconditionally.</p> |
674 | I/O unconditionally.</p> |
589 | </dd> |
675 | </dd> |
590 | </dl> |
676 | </dl> |
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677 | <p>Example: call <code>stdin_readable_cb</code> when STDIN_FILENO has become, well |
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678 | readable, but only once. Since it is likely line-buffered, you could |
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679 | attempt to read a whole line in the callback:</p> |
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680 | <pre> static void |
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681 | stdin_readable_cb (struct ev_loop *loop, struct ev_io *w, int revents) |
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682 | { |
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683 | ev_io_stop (loop, w); |
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684 | .. read from stdin here (or from w->fd) and haqndle any I/O errors |
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685 | } |
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686 | |
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687 | ... |
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688 | struct ev_loop *loop = ev_default_init (0); |
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689 | struct ev_io stdin_readable; |
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690 | ev_io_init (&stdin_readable, stdin_readable_cb, STDIN_FILENO, EV_READ); |
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691 | ev_io_start (loop, &stdin_readable); |
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692 | ev_loop (loop, 0); |
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693 | |
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694 | |
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695 | |
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696 | |
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697 | </pre> |
591 | |
698 | |
592 | </div> |
699 | </div> |
593 | <h2 id="code_ev_timer_code_relative_and_opti"><code>ev_timer</code> - relative and optionally recurring timeouts</h2> |
700 | <h2 id="code_ev_timer_code_relative_and_opti"><code>ev_timer</code> - relative and optionally recurring timeouts</h2> |
594 | <div id="code_ev_timer_code_relative_and_opti-2"> |
701 | <div id="code_ev_timer_code_relative_and_opti-2"> |
595 | <p>Timer watchers are simple relative timers that generate an event after a |
702 | <p>Timer watchers are simple relative timers that generate an event after a |
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639 | time you successfully read or write some data. If you go into an idle |
746 | time you successfully read or write some data. If you go into an idle |
640 | state where you do not expect data to travel on the socket, you can stop |
747 | state where you do not expect data to travel on the socket, you can stop |
641 | the timer, and again will automatically restart it if need be.</p> |
748 | the timer, and again will automatically restart it if need be.</p> |
642 | </dd> |
749 | </dd> |
643 | </dl> |
750 | </dl> |
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751 | <p>Example: create a timer that fires after 60 seconds.</p> |
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752 | <pre> static void |
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753 | one_minute_cb (struct ev_loop *loop, struct ev_timer *w, int revents) |
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754 | { |
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755 | .. one minute over, w is actually stopped right here |
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756 | } |
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757 | |
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758 | struct ev_timer mytimer; |
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759 | ev_timer_init (&mytimer, one_minute_cb, 60., 0.); |
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760 | ev_timer_start (loop, &mytimer); |
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761 | |
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762 | </pre> |
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763 | <p>Example: create a timeout timer that times out after 10 seconds of |
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764 | inactivity.</p> |
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765 | <pre> static void |
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766 | timeout_cb (struct ev_loop *loop, struct ev_timer *w, int revents) |
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767 | { |
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768 | .. ten seconds without any activity |
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769 | } |
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770 | |
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771 | struct ev_timer mytimer; |
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772 | ev_timer_init (&mytimer, timeout_cb, 0., 10.); /* note, only repeat used */ |
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773 | ev_timer_again (&mytimer); /* start timer */ |
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774 | ev_loop (loop, 0); |
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775 | |
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776 | // and in some piece of code that gets executed on any "activity": |
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777 | // reset the timeout to start ticking again at 10 seconds |
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778 | ev_timer_again (&mytimer); |
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779 | |
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780 | |
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781 | |
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782 | |
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783 | </pre> |
644 | |
784 | |
645 | </div> |
785 | </div> |
646 | <h2 id="code_ev_periodic_code_to_cron_or_not"><code>ev_periodic</code> - to cron or not to cron</h2> |
786 | <h2 id="code_ev_periodic_code_to_cron_or_not"><code>ev_periodic</code> - to cron or not to cron</h2> |
647 | <div id="code_ev_periodic_code_to_cron_or_not-2"> |
787 | <div id="code_ev_periodic_code_to_cron_or_not-2"> |
648 | <p>Periodic watchers are also timers of a kind, but they are very versatile |
788 | <p>Periodic watchers are also timers of a kind, but they are very versatile |
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732 | when you changed some parameters or the reschedule callback would return |
872 | when you changed some parameters or the reschedule callback would return |
733 | a different time than the last time it was called (e.g. in a crond like |
873 | a different time than the last time it was called (e.g. in a crond like |
734 | program when the crontabs have changed).</p> |
874 | program when the crontabs have changed).</p> |
735 | </dd> |
875 | </dd> |
736 | </dl> |
876 | </dl> |
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|
877 | <p>Example: call a callback every hour, or, more precisely, whenever the |
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878 | system clock is divisible by 3600. The callback invocation times have |
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879 | potentially a lot of jittering, but good long-term stability.</p> |
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|
880 | <pre> static void |
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881 | clock_cb (struct ev_loop *loop, struct ev_io *w, int revents) |
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882 | { |
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883 | ... its now a full hour (UTC, or TAI or whatever your clock follows) |
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884 | } |
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885 | |
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886 | struct ev_periodic hourly_tick; |
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887 | ev_periodic_init (&hourly_tick, clock_cb, 0., 3600., 0); |
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888 | ev_periodic_start (loop, &hourly_tick); |
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889 | |
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|
890 | </pre> |
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|
891 | <p>Example: the same as above, but use a reschedule callback to do it:</p> |
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|
892 | <pre> #include <math.h> |
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893 | |
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894 | static ev_tstamp |
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895 | my_scheduler_cb (struct ev_periodic *w, ev_tstamp now) |
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896 | { |
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897 | return fmod (now, 3600.) + 3600.; |
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898 | } |
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899 | |
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900 | ev_periodic_init (&hourly_tick, clock_cb, 0., 0., my_scheduler_cb); |
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901 | |
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|
902 | </pre> |
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|
903 | <p>Example: call a callback every hour, starting now:</p> |
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|
904 | <pre> struct ev_periodic hourly_tick; |
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905 | ev_periodic_init (&hourly_tick, clock_cb, |
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906 | fmod (ev_now (loop), 3600.), 3600., 0); |
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907 | ev_periodic_start (loop, &hourly_tick); |
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908 | |
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909 | |
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910 | |
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911 | |
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912 | </pre> |
737 | |
913 | |
738 | </div> |
914 | </div> |
739 | <h2 id="code_ev_signal_code_signal_me_when_a"><code>ev_signal</code> - signal me when a signal gets signalled</h2> |
915 | <h2 id="code_ev_signal_code_signal_me_when_a"><code>ev_signal</code> - signal me when a signal gets signalled</h2> |
740 | <div id="code_ev_signal_code_signal_me_when_a-2"> |
916 | <div id="code_ev_signal_code_signal_me_when_a-2"> |
741 | <p>Signal watchers will trigger an event when the process receives a specific |
917 | <p>Signal watchers will trigger an event when the process receives a specific |
… | |
… | |
772 | the status word (use the macros from <code>sys/wait.h</code> and see your systems |
948 | the status word (use the macros from <code>sys/wait.h</code> and see your systems |
773 | <code>waitpid</code> documentation). The <code>rpid</code> member contains the pid of the |
949 | <code>waitpid</code> documentation). The <code>rpid</code> member contains the pid of the |
774 | process causing the status change.</p> |
950 | process causing the status change.</p> |
775 | </dd> |
951 | </dd> |
776 | </dl> |
952 | </dl> |
|
|
953 | <p>Example: try to exit cleanly on SIGINT and SIGTERM.</p> |
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|
954 | <pre> static void |
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955 | sigint_cb (struct ev_loop *loop, struct ev_signal *w, int revents) |
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956 | { |
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957 | ev_unloop (loop, EVUNLOOP_ALL); |
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958 | } |
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959 | |
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|
960 | struct ev_signal signal_watcher; |
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961 | ev_signal_init (&signal_watcher, sigint_cb, SIGINT); |
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|
962 | ev_signal_start (loop, &sigint_cb); |
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963 | |
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|
964 | |
|
|
965 | |
|
|
966 | |
|
|
967 | </pre> |
777 | |
968 | |
778 | </div> |
969 | </div> |
779 | <h2 id="code_ev_idle_code_when_you_ve_got_no"><code>ev_idle</code> - when you've got nothing better to do</h2> |
970 | <h2 id="code_ev_idle_code_when_you_ve_got_no"><code>ev_idle</code> - when you've got nothing better to do</h2> |
780 | <div id="code_ev_idle_code_when_you_ve_got_no-2"> |
971 | <div id="code_ev_idle_code_when_you_ve_got_no-2"> |
781 | <p>Idle watchers trigger events when there are no other events are pending |
972 | <p>Idle watchers trigger events when there are no other events are pending |
… | |
… | |
797 | <p>Initialises and configures the idle watcher - it has no parameters of any |
988 | <p>Initialises and configures the idle watcher - it has no parameters of any |
798 | kind. There is a <code>ev_idle_set</code> macro, but using it is utterly pointless, |
989 | kind. There is a <code>ev_idle_set</code> macro, but using it is utterly pointless, |
799 | believe me.</p> |
990 | believe me.</p> |
800 | </dd> |
991 | </dd> |
801 | </dl> |
992 | </dl> |
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|
993 | <p>Example: dynamically allocate an <code>ev_idle</code>, start it, and in the |
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994 | callback, free it. Alos, use no error checking, as usual.</p> |
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|
995 | <pre> static void |
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996 | idle_cb (struct ev_loop *loop, struct ev_idle *w, int revents) |
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997 | { |
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|
998 | free (w); |
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999 | // now do something you wanted to do when the program has |
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|
1000 | // no longer asnything immediate to do. |
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|
1001 | } |
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1002 | |
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|
1003 | struct ev_idle *idle_watcher = malloc (sizeof (struct ev_idle)); |
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|
1004 | ev_idle_init (idle_watcher, idle_cb); |
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|
1005 | ev_idle_start (loop, idle_cb); |
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|
1006 | |
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1007 | |
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|
1008 | |
|
|
1009 | |
|
|
1010 | </pre> |
802 | |
1011 | |
803 | </div> |
1012 | </div> |
804 | <h2 id="code_ev_prepare_code_and_code_ev_che"><code>ev_prepare</code> and <code>ev_check</code> - customise your event loop</h2> |
1013 | <h2 id="code_ev_prepare_code_and_code_ev_che"><code>ev_prepare</code> and <code>ev_check</code> - customise your event loop</h2> |
805 | <div id="code_ev_prepare_code_and_code_ev_che-2"> |
1014 | <div id="code_ev_prepare_code_and_code_ev_che-2"> |
806 | <p>Prepare and check watchers are usually (but not always) used in tandem: |
1015 | <p>Prepare and check watchers are usually (but not always) used in tandem: |
… | |
… | |
832 | <p>Initialises and configures the prepare or check watcher - they have no |
1041 | <p>Initialises and configures the prepare or check watcher - they have no |
833 | parameters of any kind. There are <code>ev_prepare_set</code> and <code>ev_check_set</code> |
1042 | parameters of any kind. There are <code>ev_prepare_set</code> and <code>ev_check_set</code> |
834 | macros, but using them is utterly, utterly and completely pointless.</p> |
1043 | macros, but using them is utterly, utterly and completely pointless.</p> |
835 | </dd> |
1044 | </dd> |
836 | </dl> |
1045 | </dl> |
|
|
1046 | <p>Example: *TODO*.</p> |
|
|
1047 | |
|
|
1048 | |
|
|
1049 | |
|
|
1050 | |
837 | |
1051 | |
838 | </div> |
1052 | </div> |
839 | <h1 id="OTHER_FUNCTIONS">OTHER FUNCTIONS</h1><p><a href="#TOP" class="toplink">Top</a></p> |
1053 | <h1 id="OTHER_FUNCTIONS">OTHER FUNCTIONS</h1><p><a href="#TOP" class="toplink">Top</a></p> |
840 | <div id="OTHER_FUNCTIONS_CONTENT"> |
1054 | <div id="OTHER_FUNCTIONS_CONTENT"> |
841 | <p>There are some other functions of possible interest. Described. Here. Now.</p> |
1055 | <p>There are some other functions of possible interest. Described. Here. Now.</p> |
… | |
… | |
885 | <dd> |
1099 | <dd> |
886 | <p>Feed an event as if the given signal occured (loop must be the default loop!).</p> |
1100 | <p>Feed an event as if the given signal occured (loop must be the default loop!).</p> |
887 | </dd> |
1101 | </dd> |
888 | </dl> |
1102 | </dl> |
889 | |
1103 | |
|
|
1104 | |
|
|
1105 | |
|
|
1106 | |
|
|
1107 | |
890 | </div> |
1108 | </div> |
891 | <h1 id="LIBEVENT_EMULATION">LIBEVENT EMULATION</h1><p><a href="#TOP" class="toplink">Top</a></p> |
1109 | <h1 id="LIBEVENT_EMULATION">LIBEVENT EMULATION</h1><p><a href="#TOP" class="toplink">Top</a></p> |
892 | <div id="LIBEVENT_EMULATION_CONTENT"> |
1110 | <div id="LIBEVENT_EMULATION_CONTENT"> |
893 | <p>Libev offers a compatibility emulation layer for libevent. It cannot |
1111 | <p>Libev offers a compatibility emulation layer for libevent. It cannot |
894 | emulate the internals of libevent, so here are some usage hints:</p> |
1112 | emulate the internals of libevent, so here are some usage hints:</p> |