… | |
… | |
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="Tue Nov 27 11:59:06 2007" /> |
9 | <meta name="created" content="Tue Nov 27 21:38:05 2007" /> |
10 | <meta name="generator" content="Pod::Xhtml 1.57" /> |
10 | <meta name="generator" content="Pod::Xhtml 1.57" /> |
11 | <link rel="stylesheet" href="http://res.tst.eu/pod.css"/></head> |
11 | <link rel="stylesheet" href="http://res.tst.eu/pod.css"/></head> |
12 | <body> |
12 | <body> |
13 | <div class="pod"> |
13 | <div class="pod"> |
14 | <!-- INDEX START --> |
14 | <!-- INDEX START --> |
15 | <h3 id="TOP">Index</h3> |
15 | <h3 id="TOP">Index</h3> |
16 | |
16 | |
17 | <ul><li><a href="#NAME">NAME</a></li> |
17 | <ul><li><a href="#NAME">NAME</a></li> |
18 | <li><a href="#SYNOPSIS">SYNOPSIS</a></li> |
18 | <li><a href="#SYNOPSIS">SYNOPSIS</a></li> |
|
|
19 | <li><a href="#EXAMPLE_PROGRAM">EXAMPLE PROGRAM</a></li> |
19 | <li><a href="#DESCRIPTION">DESCRIPTION</a></li> |
20 | <li><a href="#DESCRIPTION">DESCRIPTION</a></li> |
20 | <li><a href="#FEATURES">FEATURES</a></li> |
21 | <li><a href="#FEATURES">FEATURES</a></li> |
21 | <li><a href="#CONVENTIONS">CONVENTIONS</a></li> |
22 | <li><a href="#CONVENTIONS">CONVENTIONS</a></li> |
22 | <li><a href="#TIME_REPRESENTATION">TIME REPRESENTATION</a></li> |
23 | <li><a href="#TIME_REPRESENTATION">TIME REPRESENTATION</a></li> |
23 | <li><a href="#GLOBAL_FUNCTIONS">GLOBAL FUNCTIONS</a></li> |
24 | <li><a href="#GLOBAL_FUNCTIONS">GLOBAL FUNCTIONS</a></li> |
… | |
… | |
59 | <li><a href="#AUTHOR">AUTHOR</a> |
60 | <li><a href="#AUTHOR">AUTHOR</a> |
60 | </li> |
61 | </li> |
61 | </ul><hr /> |
62 | </ul><hr /> |
62 | <!-- INDEX END --> |
63 | <!-- INDEX END --> |
63 | |
64 | |
64 | <h1 id="NAME">NAME</h1><p><a href="#TOP" class="toplink">Top</a></p> |
65 | <h1 id="NAME">NAME</h1> |
65 | <div id="NAME_CONTENT"> |
66 | <div id="NAME_CONTENT"> |
66 | <p>libev - a high performance full-featured event loop written in C</p> |
67 | <p>libev - a high performance full-featured event loop written in C</p> |
67 | |
68 | |
68 | </div> |
69 | </div> |
69 | <h1 id="SYNOPSIS">SYNOPSIS</h1><p><a href="#TOP" class="toplink">Top</a></p> |
70 | <h1 id="SYNOPSIS">SYNOPSIS</h1> |
70 | <div id="SYNOPSIS_CONTENT"> |
71 | <div id="SYNOPSIS_CONTENT"> |
71 | <pre> #include <ev.h> |
72 | <pre> #include <ev.h> |
72 | |
73 | |
73 | </pre> |
74 | </pre> |
74 | |
75 | |
75 | </div> |
76 | </div> |
76 | <h1 id="DESCRIPTION">DESCRIPTION</h1><p><a href="#TOP" class="toplink">Top</a></p> |
77 | <h1 id="EXAMPLE_PROGRAM">EXAMPLE PROGRAM</h1> |
|
|
78 | <div id="EXAMPLE_PROGRAM_CONTENT"> |
|
|
79 | <pre> #include <ev.h> |
|
|
80 | |
|
|
81 | ev_io stdin_watcher; |
|
|
82 | ev_timer timeout_watcher; |
|
|
83 | |
|
|
84 | /* called when data readable on stdin */ |
|
|
85 | static void |
|
|
86 | stdin_cb (EV_P_ struct ev_io *w, int revents) |
|
|
87 | { |
|
|
88 | /* puts ("stdin ready"); */ |
|
|
89 | ev_io_stop (EV_A_ w); /* just a syntax example */ |
|
|
90 | ev_unloop (EV_A_ EVUNLOOP_ALL); /* leave all loop calls */ |
|
|
91 | } |
|
|
92 | |
|
|
93 | static void |
|
|
94 | timeout_cb (EV_P_ struct ev_timer *w, int revents) |
|
|
95 | { |
|
|
96 | /* puts ("timeout"); */ |
|
|
97 | ev_unloop (EV_A_ EVUNLOOP_ONE); /* leave one loop call */ |
|
|
98 | } |
|
|
99 | |
|
|
100 | int |
|
|
101 | main (void) |
|
|
102 | { |
|
|
103 | struct ev_loop *loop = ev_default_loop (0); |
|
|
104 | |
|
|
105 | /* initialise an io watcher, then start it */ |
|
|
106 | ev_io_init (&stdin_watcher, stdin_cb, /*STDIN_FILENO*/ 0, EV_READ); |
|
|
107 | ev_io_start (loop, &stdin_watcher); |
|
|
108 | |
|
|
109 | /* simple non-repeating 5.5 second timeout */ |
|
|
110 | ev_timer_init (&timeout_watcher, timeout_cb, 5.5, 0.); |
|
|
111 | ev_timer_start (loop, &timeout_watcher); |
|
|
112 | |
|
|
113 | /* loop till timeout or data ready */ |
|
|
114 | ev_loop (loop, 0); |
|
|
115 | |
|
|
116 | return 0; |
|
|
117 | } |
|
|
118 | |
|
|
119 | </pre> |
|
|
120 | |
|
|
121 | </div> |
|
|
122 | <h1 id="DESCRIPTION">DESCRIPTION</h1> |
77 | <div id="DESCRIPTION_CONTENT"> |
123 | <div id="DESCRIPTION_CONTENT"> |
78 | <p>Libev is an event loop: you register interest in certain events (such as a |
124 | <p>Libev is an event loop: you register interest in certain events (such as a |
79 | file descriptor being readable or a timeout occuring), and it will manage |
125 | file descriptor being readable or a timeout occuring), and it will manage |
80 | these event sources and provide your program with events.</p> |
126 | these event sources and provide your program with events.</p> |
81 | <p>To do this, it must take more or less complete control over your process |
127 | <p>To do this, it must take more or less complete control over your process |
… | |
… | |
85 | watchers</i>, which are relatively small C structures you initialise with the |
131 | watchers</i>, which are relatively small C structures you initialise with the |
86 | details of the event, and then hand it over to libev by <i>starting</i> the |
132 | details of the event, and then hand it over to libev by <i>starting</i> the |
87 | watcher.</p> |
133 | watcher.</p> |
88 | |
134 | |
89 | </div> |
135 | </div> |
90 | <h1 id="FEATURES">FEATURES</h1><p><a href="#TOP" class="toplink">Top</a></p> |
136 | <h1 id="FEATURES">FEATURES</h1> |
91 | <div id="FEATURES_CONTENT"> |
137 | <div id="FEATURES_CONTENT"> |
92 | <p>Libev supports select, poll, the linux-specific epoll and the bsd-specific |
138 | <p>Libev supports <code>select</code>, <code>poll</code>, the linux-specific <code>epoll</code>, the |
93 | kqueue mechanisms for file descriptor events, relative timers, absolute |
139 | bsd-specific <code>kqueue</code> and the solaris-specific event port mechanisms |
94 | timers with customised rescheduling, signal events, process status change |
140 | for file descriptor events (<code>ev_io</code>), relative timers (<code>ev_timer</code>), |
95 | events (related to SIGCHLD), and event watchers dealing with the event |
141 | absolute timers with customised rescheduling (<code>ev_periodic</code>), synchronous |
96 | loop mechanism itself (idle, prepare and check watchers). It also is quite |
142 | signals (<code>ev_signal</code>), process status change events (<code>ev_child</code>), and |
|
|
143 | event watchers dealing with the event loop mechanism itself (<code>ev_idle</code>, |
|
|
144 | <code>ev_embed</code>, <code>ev_prepare</code> and <code>ev_check</code> watchers) as well as |
|
|
145 | file watchers (<code>ev_stat</code>) and even limited support for fork events |
|
|
146 | (<code>ev_fork</code>).</p> |
|
|
147 | <p>It also is quite fast (see this |
97 | fast (see this <a href="http://libev.schmorp.de/bench.html">benchmark</a> comparing |
148 | <a href="http://libev.schmorp.de/bench.html">benchmark</a> comparing it to libevent |
98 | it to libevent for example).</p> |
149 | for example).</p> |
99 | |
150 | |
100 | </div> |
151 | </div> |
101 | <h1 id="CONVENTIONS">CONVENTIONS</h1><p><a href="#TOP" class="toplink">Top</a></p> |
152 | <h1 id="CONVENTIONS">CONVENTIONS</h1> |
102 | <div id="CONVENTIONS_CONTENT"> |
153 | <div id="CONVENTIONS_CONTENT"> |
103 | <p>Libev is very configurable. In this manual the default configuration |
154 | <p>Libev is very configurable. In this manual the default configuration will |
104 | will be described, which supports multiple event loops. For more info |
155 | be described, which supports multiple event loops. For more info about |
105 | about various configuration options please have a look at the file |
156 | various configuration options please have a look at <strong>EMBED</strong> section in |
106 | <cite>README.embed</cite> in the libev distribution. If libev was configured without |
157 | this manual. If libev was configured without support for multiple event |
107 | support for multiple event loops, then all functions taking an initial |
158 | loops, then all functions taking an initial argument of name <code>loop</code> |
108 | argument of name <code>loop</code> (which is always of type <code>struct ev_loop *</code>) |
159 | (which is always of type <code>struct ev_loop *</code>) will not have this argument.</p> |
109 | will not have this argument.</p> |
|
|
110 | |
160 | |
111 | </div> |
161 | </div> |
112 | <h1 id="TIME_REPRESENTATION">TIME REPRESENTATION</h1><p><a href="#TOP" class="toplink">Top</a></p> |
162 | <h1 id="TIME_REPRESENTATION">TIME REPRESENTATION</h1> |
113 | <div id="TIME_REPRESENTATION_CONTENT"> |
163 | <div id="TIME_REPRESENTATION_CONTENT"> |
114 | <p>Libev represents time as a single floating point number, representing the |
164 | <p>Libev represents time as a single floating point number, representing the |
115 | (fractional) number of seconds since the (POSIX) epoch (somewhere near |
165 | (fractional) number of seconds since the (POSIX) epoch (somewhere near |
116 | the beginning of 1970, details are complicated, don't ask). This type is |
166 | the beginning of 1970, details are complicated, don't ask). This type is |
117 | called <code>ev_tstamp</code>, which is what you should use too. It usually aliases |
167 | called <code>ev_tstamp</code>, which is what you should use too. It usually aliases |
118 | to the <code>double</code> type in C, and when you need to do any calculations on |
168 | to the <code>double</code> type in C, and when you need to do any calculations on |
119 | it, you should treat it as such.</p> |
169 | it, you should treat it as such.</p> |
120 | |
170 | |
121 | </div> |
171 | </div> |
122 | <h1 id="GLOBAL_FUNCTIONS">GLOBAL FUNCTIONS</h1><p><a href="#TOP" class="toplink">Top</a></p> |
172 | <h1 id="GLOBAL_FUNCTIONS">GLOBAL FUNCTIONS</h1> |
123 | <div id="GLOBAL_FUNCTIONS_CONTENT"> |
173 | <div id="GLOBAL_FUNCTIONS_CONTENT"> |
124 | <p>These functions can be called anytime, even before initialising the |
174 | <p>These functions can be called anytime, even before initialising the |
125 | library in any way.</p> |
175 | library in any way.</p> |
126 | <dl> |
176 | <dl> |
127 | <dt>ev_tstamp ev_time ()</dt> |
177 | <dt>ev_tstamp ev_time ()</dt> |
… | |
… | |
140 | version of the library your program was compiled against.</p> |
190 | version of the library your program was compiled against.</p> |
141 | <p>Usually, it's a good idea to terminate if the major versions mismatch, |
191 | <p>Usually, it's a good idea to terminate if the major versions mismatch, |
142 | as this indicates an incompatible change. Minor versions are usually |
192 | as this indicates an incompatible change. Minor versions are usually |
143 | compatible to older versions, so a larger minor version alone is usually |
193 | compatible to older versions, so a larger minor version alone is usually |
144 | not a problem.</p> |
194 | not a problem.</p> |
145 | <p>Example: make sure we haven't accidentally been linked against the wrong |
195 | <p>Example: Make sure we haven't accidentally been linked against the wrong |
146 | version:</p> |
196 | version.</p> |
147 | <pre> assert (("libev version mismatch", |
197 | <pre> assert (("libev version mismatch", |
148 | ev_version_major () == EV_VERSION_MAJOR |
198 | ev_version_major () == EV_VERSION_MAJOR |
149 | && ev_version_minor () >= EV_VERSION_MINOR)); |
199 | && ev_version_minor () >= EV_VERSION_MINOR)); |
150 | |
200 | |
151 | </pre> |
201 | </pre> |
… | |
… | |
179 | might be supported on the current system, you would need to look at |
229 | might be supported on the current system, you would need to look at |
180 | <code>ev_embeddable_backends () & ev_supported_backends ()</code>, likewise for |
230 | <code>ev_embeddable_backends () & ev_supported_backends ()</code>, likewise for |
181 | recommended ones.</p> |
231 | recommended ones.</p> |
182 | <p>See the description of <code>ev_embed</code> watchers for more info.</p> |
232 | <p>See the description of <code>ev_embed</code> watchers for more info.</p> |
183 | </dd> |
233 | </dd> |
184 | <dt>ev_set_allocator (void *(*cb)(void *ptr, long size))</dt> |
234 | <dt>ev_set_allocator (void *(*cb)(void *ptr, size_t size))</dt> |
185 | <dd> |
235 | <dd> |
186 | <p>Sets the allocation function to use (the prototype is similar to the |
236 | <p>Sets the allocation function to use (the prototype and semantics are |
187 | realloc C function, the semantics are identical). It is used to allocate |
237 | identical to the realloc C function). It is used to allocate and free |
188 | and free memory (no surprises here). If it returns zero when memory |
238 | memory (no surprises here). If it returns zero when memory needs to be |
189 | needs to be allocated, the library might abort or take some potentially |
239 | allocated, the library might abort or take some potentially destructive |
190 | destructive action. The default is your system realloc function.</p> |
240 | action. The default is your system realloc function.</p> |
191 | <p>You could override this function in high-availability programs to, say, |
241 | <p>You could override this function in high-availability programs to, say, |
192 | free some memory if it cannot allocate memory, to use a special allocator, |
242 | free some memory if it cannot allocate memory, to use a special allocator, |
193 | or even to sleep a while and retry until some memory is available.</p> |
243 | or even to sleep a while and retry until some memory is available.</p> |
194 | <p>Example: replace the libev allocator with one that waits a bit and then |
244 | <p>Example: Replace the libev allocator with one that waits a bit and then |
195 | retries: better than mine).</p> |
245 | retries).</p> |
196 | <pre> static void * |
246 | <pre> static void * |
197 | persistent_realloc (void *ptr, long size) |
247 | persistent_realloc (void *ptr, size_t size) |
198 | { |
248 | { |
199 | for (;;) |
249 | for (;;) |
200 | { |
250 | { |
201 | void *newptr = realloc (ptr, size); |
251 | void *newptr = realloc (ptr, size); |
202 | |
252 | |
… | |
… | |
219 | indicating the system call or subsystem causing the problem. If this |
269 | indicating the system call or subsystem causing the problem. If this |
220 | callback is set, then libev will expect it to remedy the sitution, no |
270 | callback is set, then libev will expect it to remedy the sitution, no |
221 | matter what, when it returns. That is, libev will generally retry the |
271 | matter what, when it returns. That is, libev will generally retry the |
222 | requested operation, or, if the condition doesn't go away, do bad stuff |
272 | requested operation, or, if the condition doesn't go away, do bad stuff |
223 | (such as abort).</p> |
273 | (such as abort).</p> |
224 | <p>Example: do the same thing as libev does internally:</p> |
274 | <p>Example: This is basically the same thing that libev does internally, too.</p> |
225 | <pre> static void |
275 | <pre> static void |
226 | fatal_error (const char *msg) |
276 | fatal_error (const char *msg) |
227 | { |
277 | { |
228 | perror (msg); |
278 | perror (msg); |
229 | abort (); |
279 | abort (); |
… | |
… | |
235 | </pre> |
285 | </pre> |
236 | </dd> |
286 | </dd> |
237 | </dl> |
287 | </dl> |
238 | |
288 | |
239 | </div> |
289 | </div> |
240 | <h1 id="FUNCTIONS_CONTROLLING_THE_EVENT_LOOP">FUNCTIONS CONTROLLING THE EVENT LOOP</h1><p><a href="#TOP" class="toplink">Top</a></p> |
290 | <h1 id="FUNCTIONS_CONTROLLING_THE_EVENT_LOOP">FUNCTIONS CONTROLLING THE EVENT LOOP</h1> |
241 | <div id="FUNCTIONS_CONTROLLING_THE_EVENT_LOOP-2"> |
291 | <div id="FUNCTIONS_CONTROLLING_THE_EVENT_LOOP-2"> |
242 | <p>An event loop is described by a <code>struct ev_loop *</code>. The library knows two |
292 | <p>An event loop is described by a <code>struct ev_loop *</code>. The library knows two |
243 | types of such loops, the <i>default</i> loop, which supports signals and child |
293 | types of such loops, the <i>default</i> loop, which supports signals and child |
244 | events, and dynamically created loops which do not.</p> |
294 | events, and dynamically created loops which do not.</p> |
245 | <p>If you use threads, a common model is to run the default event loop |
295 | <p>If you use threads, a common model is to run the default event loop |
… | |
… | |
365 | <dd> |
415 | <dd> |
366 | <p>Similar to <code>ev_default_loop</code>, but always creates a new event loop that is |
416 | <p>Similar to <code>ev_default_loop</code>, but always creates a new event loop that is |
367 | always distinct from the default loop. Unlike the default loop, it cannot |
417 | always distinct from the default loop. Unlike the default loop, it cannot |
368 | handle signal and child watchers, and attempts to do so will be greeted by |
418 | handle signal and child watchers, and attempts to do so will be greeted by |
369 | undefined behaviour (or a failed assertion if assertions are enabled).</p> |
419 | undefined behaviour (or a failed assertion if assertions are enabled).</p> |
370 | <p>Example: try to create a event loop that uses epoll and nothing else.</p> |
420 | <p>Example: Try to create a event loop that uses epoll and nothing else.</p> |
371 | <pre> struct ev_loop *epoller = ev_loop_new (EVBACKEND_EPOLL | EVFLAG_NOENV); |
421 | <pre> struct ev_loop *epoller = ev_loop_new (EVBACKEND_EPOLL | EVFLAG_NOENV); |
372 | if (!epoller) |
422 | if (!epoller) |
373 | fatal ("no epoll found here, maybe it hides under your chair"); |
423 | fatal ("no epoll found here, maybe it hides under your chair"); |
374 | |
424 | |
375 | </pre> |
425 | </pre> |
… | |
… | |
468 | be handled here by queueing them when their watcher gets executed. |
518 | be handled here by queueing them when their watcher gets executed. |
469 | - If ev_unloop has been called or EVLOOP_ONESHOT or EVLOOP_NONBLOCK |
519 | - If ev_unloop has been called or EVLOOP_ONESHOT or EVLOOP_NONBLOCK |
470 | were used, return, otherwise continue with step *. |
520 | were used, return, otherwise continue with step *. |
471 | |
521 | |
472 | </pre> |
522 | </pre> |
473 | <p>Example: queue some jobs and then loop until no events are outsanding |
523 | <p>Example: Queue some jobs and then loop until no events are outsanding |
474 | anymore.</p> |
524 | anymore.</p> |
475 | <pre> ... queue jobs here, make sure they register event watchers as long |
525 | <pre> ... queue jobs here, make sure they register event watchers as long |
476 | ... as they still have work to do (even an idle watcher will do..) |
526 | ... as they still have work to do (even an idle watcher will do..) |
477 | ev_loop (my_loop, 0); |
527 | ev_loop (my_loop, 0); |
478 | ... jobs done. yeah! |
528 | ... jobs done. yeah! |
… | |
… | |
497 | example, libev itself uses this for its internal signal pipe: It is not |
547 | example, libev itself uses this for its internal signal pipe: It is not |
498 | visible to the libev user and should not keep <code>ev_loop</code> from exiting if |
548 | visible to the libev user and should not keep <code>ev_loop</code> from exiting if |
499 | no event watchers registered by it are active. It is also an excellent |
549 | no event watchers registered by it are active. It is also an excellent |
500 | way to do this for generic recurring timers or from within third-party |
550 | way to do this for generic recurring timers or from within third-party |
501 | libraries. Just remember to <i>unref after start</i> and <i>ref before stop</i>.</p> |
551 | libraries. Just remember to <i>unref after start</i> and <i>ref before stop</i>.</p> |
502 | <p>Example: create a signal watcher, but keep it from keeping <code>ev_loop</code> |
552 | <p>Example: Create a signal watcher, but keep it from keeping <code>ev_loop</code> |
503 | running when nothing else is active.</p> |
553 | running when nothing else is active.</p> |
504 | <pre> struct dv_signal exitsig; |
554 | <pre> struct ev_signal exitsig; |
505 | ev_signal_init (&exitsig, sig_cb, SIGINT); |
555 | ev_signal_init (&exitsig, sig_cb, SIGINT); |
506 | ev_signal_start (myloop, &exitsig); |
556 | ev_signal_start (loop, &exitsig); |
507 | evf_unref (myloop); |
557 | evf_unref (loop); |
508 | |
558 | |
509 | </pre> |
559 | </pre> |
510 | <p>Example: for some weird reason, unregister the above signal handler again.</p> |
560 | <p>Example: For some weird reason, unregister the above signal handler again.</p> |
511 | <pre> ev_ref (myloop); |
561 | <pre> ev_ref (loop); |
512 | ev_signal_stop (myloop, &exitsig); |
562 | ev_signal_stop (loop, &exitsig); |
513 | |
563 | |
514 | </pre> |
564 | </pre> |
515 | </dd> |
565 | </dd> |
516 | </dl> |
566 | </dl> |
517 | |
567 | |
518 | |
568 | |
519 | |
569 | |
520 | |
570 | |
521 | |
571 | |
522 | </div> |
572 | </div> |
523 | <h1 id="ANATOMY_OF_A_WATCHER">ANATOMY OF A WATCHER</h1><p><a href="#TOP" class="toplink">Top</a></p> |
573 | <h1 id="ANATOMY_OF_A_WATCHER">ANATOMY OF A WATCHER</h1> |
524 | <div id="ANATOMY_OF_A_WATCHER_CONTENT"> |
574 | <div id="ANATOMY_OF_A_WATCHER_CONTENT"> |
525 | <p>A watcher is a structure that you create and register to record your |
575 | <p>A watcher is a structure that you create and register to record your |
526 | interest in some event. For instance, if you want to wait for STDIN to |
576 | interest in some event. For instance, if you want to wait for STDIN to |
527 | become readable, you would create an <code>ev_io</code> watcher for that:</p> |
577 | become readable, you would create an <code>ev_io</code> watcher for that:</p> |
528 | <pre> static void my_cb (struct ev_loop *loop, struct ev_io *w, int revents) |
578 | <pre> static void my_cb (struct ev_loop *loop, struct ev_io *w, int revents) |
… | |
… | |
691 | events but its callback has not yet been invoked). As long as a watcher |
741 | events but its callback has not yet been invoked). As long as a watcher |
692 | is pending (but not active) you must not call an init function on it (but |
742 | is pending (but not active) you must not call an init function on it (but |
693 | <code>ev_TYPE_set</code> is safe) and you must make sure the watcher is available to |
743 | <code>ev_TYPE_set</code> is safe) and you must make sure the watcher is available to |
694 | libev (e.g. you cnanot <code>free ()</code> it).</p> |
744 | libev (e.g. you cnanot <code>free ()</code> it).</p> |
695 | </dd> |
745 | </dd> |
696 | <dt>callback = ev_cb (ev_TYPE *watcher)</dt> |
746 | <dt>callback ev_cb (ev_TYPE *watcher)</dt> |
697 | <dd> |
747 | <dd> |
698 | <p>Returns the callback currently set on the watcher.</p> |
748 | <p>Returns the callback currently set on the watcher.</p> |
699 | </dd> |
749 | </dd> |
700 | <dt>ev_cb_set (ev_TYPE *watcher, callback)</dt> |
750 | <dt>ev_cb_set (ev_TYPE *watcher, callback)</dt> |
701 | <dd> |
751 | <dd> |
… | |
… | |
733 | struct my_io *w = (struct my_io *)w_; |
783 | struct my_io *w = (struct my_io *)w_; |
734 | ... |
784 | ... |
735 | } |
785 | } |
736 | |
786 | |
737 | </pre> |
787 | </pre> |
738 | <p>More interesting and less C-conformant ways of catsing your callback type |
788 | <p>More interesting and less C-conformant ways of casting your callback type |
739 | have been omitted....</p> |
789 | instead have been omitted.</p> |
|
|
790 | <p>Another common scenario is having some data structure with multiple |
|
|
791 | watchers:</p> |
|
|
792 | <pre> struct my_biggy |
|
|
793 | { |
|
|
794 | int some_data; |
|
|
795 | ev_timer t1; |
|
|
796 | ev_timer t2; |
|
|
797 | } |
740 | |
798 | |
|
|
799 | </pre> |
|
|
800 | <p>In this case getting the pointer to <code>my_biggy</code> is a bit more complicated, |
|
|
801 | you need to use <code>offsetof</code>:</p> |
|
|
802 | <pre> #include <stddef.h> |
741 | |
803 | |
|
|
804 | static void |
|
|
805 | t1_cb (EV_P_ struct ev_timer *w, int revents) |
|
|
806 | { |
|
|
807 | struct my_biggy big = (struct my_biggy * |
|
|
808 | (((char *)w) - offsetof (struct my_biggy, t1)); |
|
|
809 | } |
742 | |
810 | |
|
|
811 | static void |
|
|
812 | t2_cb (EV_P_ struct ev_timer *w, int revents) |
|
|
813 | { |
|
|
814 | struct my_biggy big = (struct my_biggy * |
|
|
815 | (((char *)w) - offsetof (struct my_biggy, t2)); |
|
|
816 | } |
743 | |
817 | |
744 | |
818 | |
|
|
819 | |
|
|
820 | |
|
|
821 | </pre> |
|
|
822 | |
745 | </div> |
823 | </div> |
746 | <h1 id="WATCHER_TYPES">WATCHER TYPES</h1><p><a href="#TOP" class="toplink">Top</a></p> |
824 | <h1 id="WATCHER_TYPES">WATCHER TYPES</h1> |
747 | <div id="WATCHER_TYPES_CONTENT"> |
825 | <div id="WATCHER_TYPES_CONTENT"> |
748 | <p>This section describes each watcher in detail, but will not repeat |
826 | <p>This section describes each watcher in detail, but will not repeat |
749 | information given in the last section. Any initialisation/set macros, |
827 | information given in the last section. Any initialisation/set macros, |
750 | functions and members specific to the watcher type are explained.</p> |
828 | functions and members specific to the watcher type are explained.</p> |
751 | <p>Members are additionally marked with either <i>[read-only]</i>, meaning that, |
829 | <p>Members are additionally marked with either <i>[read-only]</i>, meaning that, |
… | |
… | |
811 | <dt>int events [read-only]</dt> |
889 | <dt>int events [read-only]</dt> |
812 | <dd> |
890 | <dd> |
813 | <p>The events being watched.</p> |
891 | <p>The events being watched.</p> |
814 | </dd> |
892 | </dd> |
815 | </dl> |
893 | </dl> |
816 | <p>Example: call <code>stdin_readable_cb</code> when STDIN_FILENO has become, well |
894 | <p>Example: Call <code>stdin_readable_cb</code> when STDIN_FILENO has become, well |
817 | readable, but only once. Since it is likely line-buffered, you could |
895 | readable, but only once. Since it is likely line-buffered, you could |
818 | attempt to read a whole line in the callback:</p> |
896 | attempt to read a whole line in the callback.</p> |
819 | <pre> static void |
897 | <pre> static void |
820 | stdin_readable_cb (struct ev_loop *loop, struct ev_io *w, int revents) |
898 | stdin_readable_cb (struct ev_loop *loop, struct ev_io *w, int revents) |
821 | { |
899 | { |
822 | ev_io_stop (loop, w); |
900 | ev_io_stop (loop, w); |
823 | .. read from stdin here (or from w->fd) and haqndle any I/O errors |
901 | .. read from stdin here (or from w->fd) and haqndle any I/O errors |
… | |
… | |
906 | <p>The current <code>repeat</code> value. Will be used each time the watcher times out |
984 | <p>The current <code>repeat</code> value. Will be used each time the watcher times out |
907 | or <code>ev_timer_again</code> is called and determines the next timeout (if any), |
985 | or <code>ev_timer_again</code> is called and determines the next timeout (if any), |
908 | which is also when any modifications are taken into account.</p> |
986 | which is also when any modifications are taken into account.</p> |
909 | </dd> |
987 | </dd> |
910 | </dl> |
988 | </dl> |
911 | <p>Example: create a timer that fires after 60 seconds.</p> |
989 | <p>Example: Create a timer that fires after 60 seconds.</p> |
912 | <pre> static void |
990 | <pre> static void |
913 | one_minute_cb (struct ev_loop *loop, struct ev_timer *w, int revents) |
991 | one_minute_cb (struct ev_loop *loop, struct ev_timer *w, int revents) |
914 | { |
992 | { |
915 | .. one minute over, w is actually stopped right here |
993 | .. one minute over, w is actually stopped right here |
916 | } |
994 | } |
… | |
… | |
918 | struct ev_timer mytimer; |
996 | struct ev_timer mytimer; |
919 | ev_timer_init (&mytimer, one_minute_cb, 60., 0.); |
997 | ev_timer_init (&mytimer, one_minute_cb, 60., 0.); |
920 | ev_timer_start (loop, &mytimer); |
998 | ev_timer_start (loop, &mytimer); |
921 | |
999 | |
922 | </pre> |
1000 | </pre> |
923 | <p>Example: create a timeout timer that times out after 10 seconds of |
1001 | <p>Example: Create a timeout timer that times out after 10 seconds of |
924 | inactivity.</p> |
1002 | inactivity.</p> |
925 | <pre> static void |
1003 | <pre> static void |
926 | timeout_cb (struct ev_loop *loop, struct ev_timer *w, int revents) |
1004 | timeout_cb (struct ev_loop *loop, struct ev_timer *w, int revents) |
927 | { |
1005 | { |
928 | .. ten seconds without any activity |
1006 | .. ten seconds without any activity |
… | |
… | |
1044 | <p>The current reschedule callback, or <code>0</code>, if this functionality is |
1122 | <p>The current reschedule callback, or <code>0</code>, if this functionality is |
1045 | switched off. Can be changed any time, but changes only take effect when |
1123 | switched off. Can be changed any time, but changes only take effect when |
1046 | the periodic timer fires or <code>ev_periodic_again</code> is being called.</p> |
1124 | the periodic timer fires or <code>ev_periodic_again</code> is being called.</p> |
1047 | </dd> |
1125 | </dd> |
1048 | </dl> |
1126 | </dl> |
1049 | <p>Example: call a callback every hour, or, more precisely, whenever the |
1127 | <p>Example: Call a callback every hour, or, more precisely, whenever the |
1050 | system clock is divisible by 3600. The callback invocation times have |
1128 | system clock is divisible by 3600. The callback invocation times have |
1051 | potentially a lot of jittering, but good long-term stability.</p> |
1129 | potentially a lot of jittering, but good long-term stability.</p> |
1052 | <pre> static void |
1130 | <pre> static void |
1053 | clock_cb (struct ev_loop *loop, struct ev_io *w, int revents) |
1131 | clock_cb (struct ev_loop *loop, struct ev_io *w, int revents) |
1054 | { |
1132 | { |
… | |
… | |
1058 | struct ev_periodic hourly_tick; |
1136 | struct ev_periodic hourly_tick; |
1059 | ev_periodic_init (&hourly_tick, clock_cb, 0., 3600., 0); |
1137 | ev_periodic_init (&hourly_tick, clock_cb, 0., 3600., 0); |
1060 | ev_periodic_start (loop, &hourly_tick); |
1138 | ev_periodic_start (loop, &hourly_tick); |
1061 | |
1139 | |
1062 | </pre> |
1140 | </pre> |
1063 | <p>Example: the same as above, but use a reschedule callback to do it:</p> |
1141 | <p>Example: The same as above, but use a reschedule callback to do it:</p> |
1064 | <pre> #include <math.h> |
1142 | <pre> #include <math.h> |
1065 | |
1143 | |
1066 | static ev_tstamp |
1144 | static ev_tstamp |
1067 | my_scheduler_cb (struct ev_periodic *w, ev_tstamp now) |
1145 | my_scheduler_cb (struct ev_periodic *w, ev_tstamp now) |
1068 | { |
1146 | { |
… | |
… | |
1070 | } |
1148 | } |
1071 | |
1149 | |
1072 | ev_periodic_init (&hourly_tick, clock_cb, 0., 0., my_scheduler_cb); |
1150 | ev_periodic_init (&hourly_tick, clock_cb, 0., 0., my_scheduler_cb); |
1073 | |
1151 | |
1074 | </pre> |
1152 | </pre> |
1075 | <p>Example: call a callback every hour, starting now:</p> |
1153 | <p>Example: Call a callback every hour, starting now:</p> |
1076 | <pre> struct ev_periodic hourly_tick; |
1154 | <pre> struct ev_periodic hourly_tick; |
1077 | ev_periodic_init (&hourly_tick, clock_cb, |
1155 | ev_periodic_init (&hourly_tick, clock_cb, |
1078 | fmod (ev_now (loop), 3600.), 3600., 0); |
1156 | fmod (ev_now (loop), 3600.), 3600., 0); |
1079 | ev_periodic_start (loop, &hourly_tick); |
1157 | ev_periodic_start (loop, &hourly_tick); |
1080 | |
1158 | |
… | |
… | |
1141 | <dd> |
1219 | <dd> |
1142 | <p>The process exit/trace status caused by <code>rpid</code> (see your systems |
1220 | <p>The process exit/trace status caused by <code>rpid</code> (see your systems |
1143 | <code>waitpid</code> and <code>sys/wait.h</code> documentation for details).</p> |
1221 | <code>waitpid</code> and <code>sys/wait.h</code> documentation for details).</p> |
1144 | </dd> |
1222 | </dd> |
1145 | </dl> |
1223 | </dl> |
1146 | <p>Example: try to exit cleanly on SIGINT and SIGTERM.</p> |
1224 | <p>Example: Try to exit cleanly on SIGINT and SIGTERM.</p> |
1147 | <pre> static void |
1225 | <pre> static void |
1148 | sigint_cb (struct ev_loop *loop, struct ev_signal *w, int revents) |
1226 | sigint_cb (struct ev_loop *loop, struct ev_signal *w, int revents) |
1149 | { |
1227 | { |
1150 | ev_unloop (loop, EVUNLOOP_ALL); |
1228 | ev_unloop (loop, EVUNLOOP_ALL); |
1151 | } |
1229 | } |
… | |
… | |
1274 | <p>Initialises and configures the idle watcher - it has no parameters of any |
1352 | <p>Initialises and configures the idle watcher - it has no parameters of any |
1275 | kind. There is a <code>ev_idle_set</code> macro, but using it is utterly pointless, |
1353 | kind. There is a <code>ev_idle_set</code> macro, but using it is utterly pointless, |
1276 | believe me.</p> |
1354 | believe me.</p> |
1277 | </dd> |
1355 | </dd> |
1278 | </dl> |
1356 | </dl> |
1279 | <p>Example: dynamically allocate an <code>ev_idle</code>, start it, and in the |
1357 | <p>Example: Dynamically allocate an <code>ev_idle</code> watcher, start it, and in the |
1280 | callback, free it. Alos, use no error checking, as usual.</p> |
1358 | callback, free it. Also, use no error checking, as usual.</p> |
1281 | <pre> static void |
1359 | <pre> static void |
1282 | idle_cb (struct ev_loop *loop, struct ev_idle *w, int revents) |
1360 | idle_cb (struct ev_loop *loop, struct ev_idle *w, int revents) |
1283 | { |
1361 | { |
1284 | free (w); |
1362 | free (w); |
1285 | // now do something you wanted to do when the program has |
1363 | // now do something you wanted to do when the program has |
… | |
… | |
1510 | |
1588 | |
1511 | |
1589 | |
1512 | |
1590 | |
1513 | |
1591 | |
1514 | </div> |
1592 | </div> |
1515 | <h1 id="OTHER_FUNCTIONS">OTHER FUNCTIONS</h1><p><a href="#TOP" class="toplink">Top</a></p> |
1593 | <h1 id="OTHER_FUNCTIONS">OTHER FUNCTIONS</h1> |
1516 | <div id="OTHER_FUNCTIONS_CONTENT"> |
1594 | <div id="OTHER_FUNCTIONS_CONTENT"> |
1517 | <p>There are some other functions of possible interest. Described. Here. Now.</p> |
1595 | <p>There are some other functions of possible interest. Described. Here. Now.</p> |
1518 | <dl> |
1596 | <dl> |
1519 | <dt>ev_once (loop, int fd, int events, ev_tstamp timeout, callback)</dt> |
1597 | <dt>ev_once (loop, int fd, int events, ev_tstamp timeout, callback)</dt> |
1520 | <dd> |
1598 | <dd> |
… | |
… | |
1567 | |
1645 | |
1568 | |
1646 | |
1569 | |
1647 | |
1570 | |
1648 | |
1571 | </div> |
1649 | </div> |
1572 | <h1 id="LIBEVENT_EMULATION">LIBEVENT EMULATION</h1><p><a href="#TOP" class="toplink">Top</a></p> |
1650 | <h1 id="LIBEVENT_EMULATION">LIBEVENT EMULATION</h1> |
1573 | <div id="LIBEVENT_EMULATION_CONTENT"> |
1651 | <div id="LIBEVENT_EMULATION_CONTENT"> |
1574 | <p>Libev offers a compatibility emulation layer for libevent. It cannot |
1652 | <p>Libev offers a compatibility emulation layer for libevent. It cannot |
1575 | emulate the internals of libevent, so here are some usage hints:</p> |
1653 | emulate the internals of libevent, so here are some usage hints:</p> |
1576 | <dl> |
1654 | <dl> |
1577 | <dt>* Use it by including <event.h>, as usual.</dt> |
1655 | <dt>* Use it by including <event.h>, as usual.</dt> |
… | |
… | |
1587 | <dt>* The libev emulation is <i>not</i> ABI compatible to libevent, you need |
1665 | <dt>* The libev emulation is <i>not</i> ABI compatible to libevent, you need |
1588 | to use the libev header file and library.</dt> |
1666 | to use the libev header file and library.</dt> |
1589 | </dl> |
1667 | </dl> |
1590 | |
1668 | |
1591 | </div> |
1669 | </div> |
1592 | <h1 id="C_SUPPORT">C++ SUPPORT</h1><p><a href="#TOP" class="toplink">Top</a></p> |
1670 | <h1 id="C_SUPPORT">C++ SUPPORT</h1> |
1593 | <div id="C_SUPPORT_CONTENT"> |
1671 | <div id="C_SUPPORT_CONTENT"> |
1594 | <p>Libev comes with some simplistic wrapper classes for C++ that mainly allow |
1672 | <p>Libev comes with some simplistic wrapper classes for C++ that mainly allow |
1595 | you to use some convinience methods to start/stop watchers and also change |
1673 | you to use some convinience methods to start/stop watchers and also change |
1596 | the callback model to a model using method callbacks on objects.</p> |
1674 | the callback model to a model using method callbacks on objects.</p> |
1597 | <p>To use it,</p> |
1675 | <p>To use it,</p> |
… | |
… | |
1692 | |
1770 | |
1693 | |
1771 | |
1694 | </pre> |
1772 | </pre> |
1695 | |
1773 | |
1696 | </div> |
1774 | </div> |
1697 | <h1 id="MACRO_MAGIC">MACRO MAGIC</h1><p><a href="#TOP" class="toplink">Top</a></p> |
1775 | <h1 id="MACRO_MAGIC">MACRO MAGIC</h1> |
1698 | <div id="MACRO_MAGIC_CONTENT"> |
1776 | <div id="MACRO_MAGIC_CONTENT"> |
1699 | <p>Libev can be compiled with a variety of options, the most fundemantal is |
1777 | <p>Libev can be compiled with a variety of options, the most fundemantal is |
1700 | <code>EV_MULTIPLICITY</code>. This option determines wether (most) functions and |
1778 | <code>EV_MULTIPLICITY</code>. This option determines wether (most) functions and |
1701 | callbacks have an initial <code>struct ev_loop *</code> argument.</p> |
1779 | callbacks have an initial <code>struct ev_loop *</code> argument.</p> |
1702 | <p>To make it easier to write programs that cope with either variant, the |
1780 | <p>To make it easier to write programs that cope with either variant, the |
… | |
… | |
1753 | |
1831 | |
1754 | |
1832 | |
1755 | </pre> |
1833 | </pre> |
1756 | |
1834 | |
1757 | </div> |
1835 | </div> |
1758 | <h1 id="EMBEDDING">EMBEDDING</h1><p><a href="#TOP" class="toplink">Top</a></p> |
1836 | <h1 id="EMBEDDING">EMBEDDING</h1> |
1759 | <div id="EMBEDDING_CONTENT"> |
1837 | <div id="EMBEDDING_CONTENT"> |
1760 | <p>Libev can (and often is) directly embedded into host |
1838 | <p>Libev can (and often is) directly embedded into host |
1761 | applications. Examples of applications that embed it include the Deliantra |
1839 | applications. Examples of applications that embed it include the Deliantra |
1762 | Game Server, the EV perl module, the GNU Virtual Private Ethernet (gvpe) |
1840 | Game Server, the EV perl module, the GNU Virtual Private Ethernet (gvpe) |
1763 | and rxvt-unicode.</p> |
1841 | and rxvt-unicode.</p> |
… | |
… | |
1995 | <dt>EV_MINIMAL</dt> |
2073 | <dt>EV_MINIMAL</dt> |
1996 | <dd> |
2074 | <dd> |
1997 | <p>If you need to shave off some kilobytes of code at the expense of some |
2075 | <p>If you need to shave off some kilobytes of code at the expense of some |
1998 | speed, define this symbol to <code>1</code>. Currently only used for gcc to override |
2076 | speed, define this symbol to <code>1</code>. Currently only used for gcc to override |
1999 | some inlining decisions, saves roughly 30% codesize of amd64.</p> |
2077 | some inlining decisions, saves roughly 30% codesize of amd64.</p> |
|
|
2078 | </dd> |
|
|
2079 | <dt>EV_PID_HASHSIZE</dt> |
|
|
2080 | <dd> |
|
|
2081 | <p><code>ev_child</code> watchers use a small hash table to distribute workload by |
|
|
2082 | pid. The default size is <code>16</code> (or <code>1</code> with <code>EV_MINIMAL</code>), usually more |
|
|
2083 | than enough. If you need to manage thousands of children you might want to |
|
|
2084 | increase this value.</p> |
2000 | </dd> |
2085 | </dd> |
2001 | <dt>EV_COMMON</dt> |
2086 | <dt>EV_COMMON</dt> |
2002 | <dd> |
2087 | <dd> |
2003 | <p>By default, all watchers have a <code>void *data</code> member. By redefining |
2088 | <p>By default, all watchers have a <code>void *data</code> member. By redefining |
2004 | this macro to a something else you can include more and other types of |
2089 | this macro to a something else you can include more and other types of |
… | |
… | |
2050 | |
2135 | |
2051 | |
2136 | |
2052 | </pre> |
2137 | </pre> |
2053 | |
2138 | |
2054 | </div> |
2139 | </div> |
2055 | <h1 id="COMPLEXITIES">COMPLEXITIES</h1><p><a href="#TOP" class="toplink">Top</a></p> |
2140 | <h1 id="COMPLEXITIES">COMPLEXITIES</h1> |
2056 | <div id="COMPLEXITIES_CONTENT"> |
2141 | <div id="COMPLEXITIES_CONTENT"> |
2057 | <p>In this section the complexities of (many of) the algorithms used inside |
2142 | <p>In this section the complexities of (many of) the algorithms used inside |
2058 | libev will be explained. For complexity discussions about backends see the |
2143 | libev will be explained. For complexity discussions about backends see the |
2059 | documentation for <code>ev_default_init</code>.</p> |
2144 | documentation for <code>ev_default_init</code>.</p> |
2060 | <p> |
2145 | <p> |
… | |
… | |
2073 | |
2158 | |
2074 | |
2159 | |
2075 | |
2160 | |
2076 | |
2161 | |
2077 | </div> |
2162 | </div> |
2078 | <h1 id="AUTHOR">AUTHOR</h1><p><a href="#TOP" class="toplink">Top</a></p> |
2163 | <h1 id="AUTHOR">AUTHOR</h1> |
2079 | <div id="AUTHOR_CONTENT"> |
2164 | <div id="AUTHOR_CONTENT"> |
2080 | <p>Marc Lehmann <libev@schmorp.de>.</p> |
2165 | <p>Marc Lehmann <libev@schmorp.de>.</p> |
2081 | |
2166 | |
2082 | </div> |
2167 | </div> |
2083 | </div></body> |
2168 | </div></body> |