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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="&lt;standard input&gt;" /> 7 <meta name="inputfile" content="&lt;standard input&gt;" />
8 <meta name="outputfile" content="&lt;standard output&gt;" /> 8 <meta name="outputfile" content="&lt;standard output&gt;" />
9 <meta name="created" content="Tue Nov 27 21:14:27 2007" /> 9 <meta name="created" content="Fri Dec 7 21:19:14 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>
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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> /* this is the only header you need */
72 #include &lt;ev.h&gt; 72<pre> #include &lt;ev.h&gt;
73 73
74 /* what follows is a fully working example program */ 74</pre>
75
76</div>
77<h1 id="EXAMPLE_PROGRAM">EXAMPLE PROGRAM</h1>
78<div id="EXAMPLE_PROGRAM_CONTENT">
79<pre> #include &lt;ev.h&gt;
80
75 ev_io stdin_watcher; 81 ev_io stdin_watcher;
76 ev_timer timeout_watcher; 82 ev_timer timeout_watcher;
77 83
78 /* called when data readable on stdin */ 84 /* called when data readable on stdin */
79 static void 85 static void
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111 } 117 }
112 118
113</pre> 119</pre>
114 120
115</div> 121</div>
116<h1 id="DESCRIPTION">DESCRIPTION</h1><p><a href="#TOP" class="toplink">Top</a></p> 122<h1 id="DESCRIPTION">DESCRIPTION</h1>
117<div id="DESCRIPTION_CONTENT"> 123<div id="DESCRIPTION_CONTENT">
124<p>The newest version of this document is also available as a html-formatted
125web page you might find easier to navigate when reading it for the first
126time: <a href="http://cvs.schmorp.de/libev/ev.html">http://cvs.schmorp.de/libev/ev.html</a>.</p>
118<p>Libev is an event loop: you register interest in certain events (such as a 127<p>Libev is an event loop: you register interest in certain events (such as a
119file descriptor being readable or a timeout occuring), and it will manage 128file descriptor being readable or a timeout occuring), and it will manage
120these event sources and provide your program with events.</p> 129these event sources and provide your program with events.</p>
121<p>To do this, it must take more or less complete control over your process 130<p>To do this, it must take more or less complete control over your process
122(or thread) by executing the <i>event loop</i> handler, and will then 131(or thread) by executing the <i>event loop</i> handler, and will then
… …
125watchers</i>, which are relatively small C structures you initialise with the 134watchers</i>, which are relatively small C structures you initialise with the
126details of the event, and then hand it over to libev by <i>starting</i> the 135details of the event, and then hand it over to libev by <i>starting</i> the
127watcher.</p> 136watcher.</p>
128 137
129</div> 138</div>
130<h1 id="FEATURES">FEATURES</h1><p><a href="#TOP" class="toplink">Top</a></p> 139<h1 id="FEATURES">FEATURES</h1>
131<div id="FEATURES_CONTENT"> 140<div id="FEATURES_CONTENT">
132<p>Libev supports select, poll, the linux-specific epoll and the bsd-specific 141<p>Libev supports <code>select</code>, <code>poll</code>, the Linux-specific <code>epoll</code>, the
133kqueue mechanisms for file descriptor events, relative timers, absolute 142BSD-specific <code>kqueue</code> and the Solaris-specific event port mechanisms
134timers with customised rescheduling, signal events, process status change 143for file descriptor events (<code>ev_io</code>), the Linux <code>inotify</code> interface
135events (related to SIGCHLD), and event watchers dealing with the event 144(for <code>ev_stat</code>), relative timers (<code>ev_timer</code>), absolute timers
136loop mechanism itself (idle, prepare and check watchers). It also is quite 145with customised rescheduling (<code>ev_periodic</code>), synchronous signals
146(<code>ev_signal</code>), process status change events (<code>ev_child</code>), and event
147watchers dealing with the event loop mechanism itself (<code>ev_idle</code>,
148<code>ev_embed</code>, <code>ev_prepare</code> and <code>ev_check</code> watchers) as well as
149file watchers (<code>ev_stat</code>) and even limited support for fork events
150(<code>ev_fork</code>).</p>
151<p>It also is quite fast (see this
137fast (see this <a href="http://libev.schmorp.de/bench.html">benchmark</a> comparing 152<a href="http://libev.schmorp.de/bench.html">benchmark</a> comparing it to libevent
138it to libevent for example).</p> 153for example).</p>
139 154
140</div> 155</div>
141<h1 id="CONVENTIONS">CONVENTIONS</h1><p><a href="#TOP" class="toplink">Top</a></p> 156<h1 id="CONVENTIONS">CONVENTIONS</h1>
142<div id="CONVENTIONS_CONTENT"> 157<div id="CONVENTIONS_CONTENT">
143<p>Libev is very configurable. In this manual the default configuration 158<p>Libev is very configurable. In this manual the default configuration will
144will be described, which supports multiple event loops. For more info 159be described, which supports multiple event loops. For more info about
145about various configuration options please have a look at the file 160various configuration options please have a look at <strong>EMBED</strong> section in
146<cite>README.embed</cite> in the libev distribution. If libev was configured without 161this manual. If libev was configured without support for multiple event
147support for multiple event loops, then all functions taking an initial 162loops, then all functions taking an initial argument of name <code>loop</code>
148argument of name <code>loop</code> (which is always of type <code>struct ev_loop *</code>) 163(which is always of type <code>struct ev_loop *</code>) will not have this argument.</p>
149will not have this argument.</p>
150 164
151</div> 165</div>
152<h1 id="TIME_REPRESENTATION">TIME REPRESENTATION</h1><p><a href="#TOP" class="toplink">Top</a></p> 166<h1 id="TIME_REPRESENTATION">TIME REPRESENTATION</h1>
153<div id="TIME_REPRESENTATION_CONTENT"> 167<div id="TIME_REPRESENTATION_CONTENT">
154<p>Libev represents time as a single floating point number, representing the 168<p>Libev represents time as a single floating point number, representing the
155(fractional) number of seconds since the (POSIX) epoch (somewhere near 169(fractional) number of seconds since the (POSIX) epoch (somewhere near
156the beginning of 1970, details are complicated, don't ask). This type is 170the beginning of 1970, details are complicated, don't ask). This type is
157called <code>ev_tstamp</code>, which is what you should use too. It usually aliases 171called <code>ev_tstamp</code>, which is what you should use too. It usually aliases
158to the <code>double</code> type in C, and when you need to do any calculations on 172to the <code>double</code> type in C, and when you need to do any calculations on
159it, you should treat it as such.</p> 173it, you should treat it as such.</p>
160 174
161</div> 175</div>
162<h1 id="GLOBAL_FUNCTIONS">GLOBAL FUNCTIONS</h1><p><a href="#TOP" class="toplink">Top</a></p> 176<h1 id="GLOBAL_FUNCTIONS">GLOBAL FUNCTIONS</h1>
163<div id="GLOBAL_FUNCTIONS_CONTENT"> 177<div id="GLOBAL_FUNCTIONS_CONTENT">
164<p>These functions can be called anytime, even before initialising the 178<p>These functions can be called anytime, even before initialising the
165library in any way.</p> 179library in any way.</p>
166<dl> 180<dl>
167 <dt>ev_tstamp ev_time ()</dt> 181 <dt>ev_tstamp ev_time ()</dt>
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180version of the library your program was compiled against.</p> 194version of the library your program was compiled against.</p>
181 <p>Usually, it's a good idea to terminate if the major versions mismatch, 195 <p>Usually, it's a good idea to terminate if the major versions mismatch,
182as this indicates an incompatible change. Minor versions are usually 196as this indicates an incompatible change. Minor versions are usually
183compatible to older versions, so a larger minor version alone is usually 197compatible to older versions, so a larger minor version alone is usually
184not a problem.</p> 198not a problem.</p>
185 <p>Example: make sure we haven't accidentally been linked against the wrong 199 <p>Example: Make sure we haven't accidentally been linked against the wrong
186version:</p> 200version.</p>
187<pre> assert ((&quot;libev version mismatch&quot;, 201<pre> assert ((&quot;libev version mismatch&quot;,
188 ev_version_major () == EV_VERSION_MAJOR 202 ev_version_major () == EV_VERSION_MAJOR
189 &amp;&amp; ev_version_minor () &gt;= EV_VERSION_MINOR)); 203 &amp;&amp; ev_version_minor () &gt;= EV_VERSION_MINOR));
190 204
191</pre> 205</pre>
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219might be supported on the current system, you would need to look at 233might be supported on the current system, you would need to look at
220<code>ev_embeddable_backends () &amp; ev_supported_backends ()</code>, likewise for 234<code>ev_embeddable_backends () &amp; ev_supported_backends ()</code>, likewise for
221recommended ones.</p> 235recommended ones.</p>
222 <p>See the description of <code>ev_embed</code> watchers for more info.</p> 236 <p>See the description of <code>ev_embed</code> watchers for more info.</p>
223 </dd> 237 </dd>
224 <dt>ev_set_allocator (void *(*cb)(void *ptr, size_t size))</dt> 238 <dt>ev_set_allocator (void *(*cb)(void *ptr, long size))</dt>
225 <dd> 239 <dd>
226 <p>Sets the allocation function to use (the prototype and semantics are 240 <p>Sets the allocation function to use (the prototype is similar - the
227identical to the realloc C function). It is used to allocate and free 241semantics is identical - to the realloc C function). It is used to
228memory (no surprises here). If it returns zero when memory needs to be 242allocate and free memory (no surprises here). If it returns zero when
229allocated, the library might abort or take some potentially destructive 243memory needs to be allocated, the library might abort or take some
230action. The default is your system realloc function.</p> 244potentially destructive action. The default is your system realloc
245function.</p>
231 <p>You could override this function in high-availability programs to, say, 246 <p>You could override this function in high-availability programs to, say,
232free some memory if it cannot allocate memory, to use a special allocator, 247free some memory if it cannot allocate memory, to use a special allocator,
233or even to sleep a while and retry until some memory is available.</p> 248or even to sleep a while and retry until some memory is available.</p>
234 <p>Example: replace the libev allocator with one that waits a bit and then 249 <p>Example: Replace the libev allocator with one that waits a bit and then
235retries: better than mine).</p> 250retries).</p>
236<pre> static void * 251<pre> static void *
237 persistent_realloc (void *ptr, size_t size) 252 persistent_realloc (void *ptr, size_t size)
238 { 253 {
239 for (;;) 254 for (;;)
240 { 255 {
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259indicating the system call or subsystem causing the problem. If this 274indicating the system call or subsystem causing the problem. If this
260callback is set, then libev will expect it to remedy the sitution, no 275callback is set, then libev will expect it to remedy the sitution, no
261matter what, when it returns. That is, libev will generally retry the 276matter what, when it returns. That is, libev will generally retry the
262requested operation, or, if the condition doesn't go away, do bad stuff 277requested operation, or, if the condition doesn't go away, do bad stuff
263(such as abort).</p> 278(such as abort).</p>
264 <p>Example: do the same thing as libev does internally:</p> 279 <p>Example: This is basically the same thing that libev does internally, too.</p>
265<pre> static void 280<pre> static void
266 fatal_error (const char *msg) 281 fatal_error (const char *msg)
267 { 282 {
268 perror (msg); 283 perror (msg);
269 abort (); 284 abort ();
… …
275</pre> 290</pre>
276 </dd> 291 </dd>
277</dl> 292</dl>
278 293
279</div> 294</div>
280<h1 id="FUNCTIONS_CONTROLLING_THE_EVENT_LOOP">FUNCTIONS CONTROLLING THE EVENT LOOP</h1><p><a href="#TOP" class="toplink">Top</a></p> 295<h1 id="FUNCTIONS_CONTROLLING_THE_EVENT_LOOP">FUNCTIONS CONTROLLING THE EVENT LOOP</h1>
281<div id="FUNCTIONS_CONTROLLING_THE_EVENT_LOOP-2"> 296<div id="FUNCTIONS_CONTROLLING_THE_EVENT_LOOP-2">
282<p>An event loop is described by a <code>struct ev_loop *</code>. The library knows two 297<p>An event loop is described by a <code>struct ev_loop *</code>. The library knows two
283types of such loops, the <i>default</i> loop, which supports signals and child 298types of such loops, the <i>default</i> loop, which supports signals and child
284events, and dynamically created loops which do not.</p> 299events, and dynamically created loops which do not.</p>
285<p>If you use threads, a common model is to run the default event loop 300<p>If you use threads, a common model is to run the default event loop
… …
314<code>LIBEV_FLAGS</code>. Otherwise (the default), this environment variable will 329<code>LIBEV_FLAGS</code>. Otherwise (the default), this environment variable will
315override the flags completely if it is found in the environment. This is 330override the flags completely if it is found in the environment. This is
316useful to try out specific backends to test their performance, or to work 331useful to try out specific backends to test their performance, or to work
317around bugs.</p> 332around bugs.</p>
318 </dd> 333 </dd>
334 <dt><code>EVFLAG_FORKCHECK</code></dt>
335 <dd>
336 <p>Instead of calling <code>ev_default_fork</code> or <code>ev_loop_fork</code> manually after
337a fork, you can also make libev check for a fork in each iteration by
338enabling this flag.</p>
339 <p>This works by calling <code>getpid ()</code> on every iteration of the loop,
340and thus this might slow down your event loop if you do a lot of loop
341iterations and little real work, but is usually not noticeable (on my
342Linux system for example, <code>getpid</code> is actually a simple 5-insn sequence
343without a syscall and thus <i>very</i> fast, but my Linux system also has
344<code>pthread_atfork</code> which is even faster).</p>
345 <p>The big advantage of this flag is that you can forget about fork (and
346forget about forgetting to tell libev about forking) when you use this
347flag.</p>
348 <p>This flag setting cannot be overriden or specified in the <code>LIBEV_FLAGS</code>
349environment variable.</p>
350 </dd>
319 <dt><code>EVBACKEND_SELECT</code> (value 1, portable select backend)</dt> 351 <dt><code>EVBACKEND_SELECT</code> (value 1, portable select backend)</dt>
320 <dd> 352 <dd>
321 <p>This is your standard select(2) backend. Not <i>completely</i> standard, as 353 <p>This is your standard select(2) backend. Not <i>completely</i> standard, as
322libev tries to roll its own fd_set with no limits on the number of fds, 354libev tries to roll its own fd_set with no limits on the number of fds,
323but if that fails, expect a fairly low limit on the number of fds when 355but if that fails, expect a fairly low limit on the number of fds when
… …
405 <dd> 437 <dd>
406 <p>Similar to <code>ev_default_loop</code>, but always creates a new event loop that is 438 <p>Similar to <code>ev_default_loop</code>, but always creates a new event loop that is
407always distinct from the default loop. Unlike the default loop, it cannot 439always distinct from the default loop. Unlike the default loop, it cannot
408handle signal and child watchers, and attempts to do so will be greeted by 440handle signal and child watchers, and attempts to do so will be greeted by
409undefined behaviour (or a failed assertion if assertions are enabled).</p> 441undefined behaviour (or a failed assertion if assertions are enabled).</p>
410 <p>Example: try to create a event loop that uses epoll and nothing else.</p> 442 <p>Example: Try to create a event loop that uses epoll and nothing else.</p>
411<pre> struct ev_loop *epoller = ev_loop_new (EVBACKEND_EPOLL | EVFLAG_NOENV); 443<pre> struct ev_loop *epoller = ev_loop_new (EVBACKEND_EPOLL | EVFLAG_NOENV);
412 if (!epoller) 444 if (!epoller)
413 fatal (&quot;no epoll found here, maybe it hides under your chair&quot;); 445 fatal (&quot;no epoll found here, maybe it hides under your chair&quot;);
414 446
415</pre> 447</pre>
… …
451 <dt>ev_loop_fork (loop)</dt> 483 <dt>ev_loop_fork (loop)</dt>
452 <dd> 484 <dd>
453 <p>Like <code>ev_default_fork</code>, but acts on an event loop created by 485 <p>Like <code>ev_default_fork</code>, but acts on an event loop created by
454<code>ev_loop_new</code>. Yes, you have to call this on every allocated event loop 486<code>ev_loop_new</code>. Yes, you have to call this on every allocated event loop
455after fork, and how you do this is entirely your own problem.</p> 487after fork, and how you do this is entirely your own problem.</p>
488 </dd>
489 <dt>unsigned int ev_loop_count (loop)</dt>
490 <dd>
491 <p>Returns the count of loop iterations for the loop, which is identical to
492the number of times libev did poll for new events. It starts at <code>0</code> and
493happily wraps around with enough iterations.</p>
494 <p>This value can sometimes be useful as a generation counter of sorts (it
495&quot;ticks&quot; the number of loop iterations), as it roughly corresponds with
496<code>ev_prepare</code> and <code>ev_check</code> calls.</p>
456 </dd> 497 </dd>
457 <dt>unsigned int ev_backend (loop)</dt> 498 <dt>unsigned int ev_backend (loop)</dt>
458 <dd> 499 <dd>
459 <p>Returns one of the <code>EVBACKEND_*</code> flags indicating the event backend in 500 <p>Returns one of the <code>EVBACKEND_*</code> flags indicating the event backend in
460use.</p> 501use.</p>
… …
508 be handled here by queueing them when their watcher gets executed. 549 be handled here by queueing them when their watcher gets executed.
509 - If ev_unloop has been called or EVLOOP_ONESHOT or EVLOOP_NONBLOCK 550 - If ev_unloop has been called or EVLOOP_ONESHOT or EVLOOP_NONBLOCK
510 were used, return, otherwise continue with step *. 551 were used, return, otherwise continue with step *.
511 552
512</pre> 553</pre>
513 <p>Example: queue some jobs and then loop until no events are outsanding 554 <p>Example: Queue some jobs and then loop until no events are outsanding
514anymore.</p> 555anymore.</p>
515<pre> ... queue jobs here, make sure they register event watchers as long 556<pre> ... queue jobs here, make sure they register event watchers as long
516 ... as they still have work to do (even an idle watcher will do..) 557 ... as they still have work to do (even an idle watcher will do..)
517 ev_loop (my_loop, 0); 558 ev_loop (my_loop, 0);
518 ... jobs done. yeah! 559 ... jobs done. yeah!
… …
537example, libev itself uses this for its internal signal pipe: It is not 578example, libev itself uses this for its internal signal pipe: It is not
538visible to the libev user and should not keep <code>ev_loop</code> from exiting if 579visible to the libev user and should not keep <code>ev_loop</code> from exiting if
539no event watchers registered by it are active. It is also an excellent 580no event watchers registered by it are active. It is also an excellent
540way to do this for generic recurring timers or from within third-party 581way to do this for generic recurring timers or from within third-party
541libraries. Just remember to <i>unref after start</i> and <i>ref before stop</i>.</p> 582libraries. Just remember to <i>unref after start</i> and <i>ref before stop</i>.</p>
542 <p>Example: create a signal watcher, but keep it from keeping <code>ev_loop</code> 583 <p>Example: Create a signal watcher, but keep it from keeping <code>ev_loop</code>
543running when nothing else is active.</p> 584running when nothing else is active.</p>
544<pre> struct dv_signal exitsig; 585<pre> struct ev_signal exitsig;
545 ev_signal_init (&amp;exitsig, sig_cb, SIGINT); 586 ev_signal_init (&amp;exitsig, sig_cb, SIGINT);
546 ev_signal_start (myloop, &amp;exitsig); 587 ev_signal_start (loop, &amp;exitsig);
547 evf_unref (myloop); 588 evf_unref (loop);
548 589
549</pre> 590</pre>
550 <p>Example: for some weird reason, unregister the above signal handler again.</p> 591 <p>Example: For some weird reason, unregister the above signal handler again.</p>
551<pre> ev_ref (myloop); 592<pre> ev_ref (loop);
552 ev_signal_stop (myloop, &amp;exitsig); 593 ev_signal_stop (loop, &amp;exitsig);
553 594
554</pre> 595</pre>
555 </dd> 596 </dd>
556</dl> 597</dl>
557 598
558 599
559 600
560 601
561 602
562</div> 603</div>
563<h1 id="ANATOMY_OF_A_WATCHER">ANATOMY OF A WATCHER</h1><p><a href="#TOP" class="toplink">Top</a></p> 604<h1 id="ANATOMY_OF_A_WATCHER">ANATOMY OF A WATCHER</h1>
564<div id="ANATOMY_OF_A_WATCHER_CONTENT"> 605<div id="ANATOMY_OF_A_WATCHER_CONTENT">
565<p>A watcher is a structure that you create and register to record your 606<p>A watcher is a structure that you create and register to record your
566interest in some event. For instance, if you want to wait for STDIN to 607interest in some event. For instance, if you want to wait for STDIN to
567become readable, you would create an <code>ev_io</code> watcher for that:</p> 608become readable, you would create an <code>ev_io</code> watcher for that:</p>
568<pre> static void my_cb (struct ev_loop *loop, struct ev_io *w, int revents) 609<pre> static void my_cb (struct ev_loop *loop, struct ev_io *w, int revents)
… …
731events but its callback has not yet been invoked). As long as a watcher 772events but its callback has not yet been invoked). As long as a watcher
732is pending (but not active) you must not call an init function on it (but 773is pending (but not active) you must not call an init function on it (but
733<code>ev_TYPE_set</code> is safe) and you must make sure the watcher is available to 774<code>ev_TYPE_set</code> is safe) and you must make sure the watcher is available to
734libev (e.g. you cnanot <code>free ()</code> it).</p> 775libev (e.g. you cnanot <code>free ()</code> it).</p>
735 </dd> 776 </dd>
736 <dt>callback = ev_cb (ev_TYPE *watcher)</dt> 777 <dt>callback ev_cb (ev_TYPE *watcher)</dt>
737 <dd> 778 <dd>
738 <p>Returns the callback currently set on the watcher.</p> 779 <p>Returns the callback currently set on the watcher.</p>
739 </dd> 780 </dd>
740 <dt>ev_cb_set (ev_TYPE *watcher, callback)</dt> 781 <dt>ev_cb_set (ev_TYPE *watcher, callback)</dt>
741 <dd> 782 <dd>
742 <p>Change the callback. You can change the callback at virtually any time 783 <p>Change the callback. You can change the callback at virtually any time
743(modulo threads).</p> 784(modulo threads).</p>
785 </dd>
786 <dt>ev_set_priority (ev_TYPE *watcher, priority)</dt>
787 <dt>int ev_priority (ev_TYPE *watcher)</dt>
788 <dd>
789 <p>Set and query the priority of the watcher. The priority is a small
790integer between <code>EV_MAXPRI</code> (default: <code>2</code>) and <code>EV_MINPRI</code>
791(default: <code>-2</code>). Pending watchers with higher priority will be invoked
792before watchers with lower priority, but priority will not keep watchers
793from being executed (except for <code>ev_idle</code> watchers).</p>
794 <p>This means that priorities are <i>only</i> used for ordering callback
795invocation after new events have been received. This is useful, for
796example, to reduce latency after idling, or more often, to bind two
797watchers on the same event and make sure one is called first.</p>
798 <p>If you need to suppress invocation when higher priority events are pending
799you need to look at <code>ev_idle</code> watchers, which provide this functionality.</p>
800 <p>The default priority used by watchers when no priority has been set is
801always <code>0</code>, which is supposed to not be too high and not be too low :).</p>
802 <p>Setting a priority outside the range of <code>EV_MINPRI</code> to <code>EV_MAXPRI</code> is
803fine, as long as you do not mind that the priority value you query might
804or might not have been adjusted to be within valid range.</p>
744 </dd> 805 </dd>
745</dl> 806</dl>
746 807
747 808
748 809
… …
773 struct my_io *w = (struct my_io *)w_; 834 struct my_io *w = (struct my_io *)w_;
774 ... 835 ...
775 } 836 }
776 837
777</pre> 838</pre>
778<p>More interesting and less C-conformant ways of catsing your callback type 839<p>More interesting and less C-conformant ways of casting your callback type
779have been omitted....</p> 840instead have been omitted.</p>
841<p>Another common scenario is having some data structure with multiple
842watchers:</p>
843<pre> struct my_biggy
844 {
845 int some_data;
846 ev_timer t1;
847 ev_timer t2;
848 }
780 849
850</pre>
851<p>In this case getting the pointer to <code>my_biggy</code> is a bit more complicated,
852you need to use <code>offsetof</code>:</p>
853<pre> #include &lt;stddef.h&gt;
781 854
855 static void
856 t1_cb (EV_P_ struct ev_timer *w, int revents)
857 {
858 struct my_biggy big = (struct my_biggy *
859 (((char *)w) - offsetof (struct my_biggy, t1));
860 }
782 861
862 static void
863 t2_cb (EV_P_ struct ev_timer *w, int revents)
864 {
865 struct my_biggy big = (struct my_biggy *
866 (((char *)w) - offsetof (struct my_biggy, t2));
867 }
783 868
784 869
870
871
872</pre>
873
785</div> 874</div>
786<h1 id="WATCHER_TYPES">WATCHER TYPES</h1><p><a href="#TOP" class="toplink">Top</a></p> 875<h1 id="WATCHER_TYPES">WATCHER TYPES</h1>
787<div id="WATCHER_TYPES_CONTENT"> 876<div id="WATCHER_TYPES_CONTENT">
788<p>This section describes each watcher in detail, but will not repeat 877<p>This section describes each watcher in detail, but will not repeat
789information given in the last section. Any initialisation/set macros, 878information given in the last section. Any initialisation/set macros,
790functions and members specific to the watcher type are explained.</p> 879functions and members specific to the watcher type are explained.</p>
791<p>Members are additionally marked with either <i>[read-only]</i>, meaning that, 880<p>Members are additionally marked with either <i>[read-only]</i>, meaning that,
… …
831this situation even with a relatively standard program structure. Thus 920this situation even with a relatively standard program structure. Thus
832it is best to always use non-blocking I/O: An extra <code>read</code>(2) returning 921it is best to always use non-blocking I/O: An extra <code>read</code>(2) returning
833<code>EAGAIN</code> is far preferable to a program hanging until some data arrives.</p> 922<code>EAGAIN</code> is far preferable to a program hanging until some data arrives.</p>
834<p>If you cannot run the fd in non-blocking mode (for example you should not 923<p>If you cannot run the fd in non-blocking mode (for example you should not
835play around with an Xlib connection), then you have to seperately re-test 924play around with an Xlib connection), then you have to seperately re-test
836wether a file descriptor is really ready with a known-to-be good interface 925whether a file descriptor is really ready with a known-to-be good interface
837such as poll (fortunately in our Xlib example, Xlib already does this on 926such as poll (fortunately in our Xlib example, Xlib already does this on
838its own, so its quite safe to use).</p> 927its own, so its quite safe to use).</p>
839<dl> 928<dl>
840 <dt>ev_io_init (ev_io *, callback, int fd, int events)</dt> 929 <dt>ev_io_init (ev_io *, callback, int fd, int events)</dt>
841 <dt>ev_io_set (ev_io *, int fd, int events)</dt> 930 <dt>ev_io_set (ev_io *, int fd, int events)</dt>
… …
851 <dt>int events [read-only]</dt> 940 <dt>int events [read-only]</dt>
852 <dd> 941 <dd>
853 <p>The events being watched.</p> 942 <p>The events being watched.</p>
854 </dd> 943 </dd>
855</dl> 944</dl>
856<p>Example: call <code>stdin_readable_cb</code> when STDIN_FILENO has become, well 945<p>Example: Call <code>stdin_readable_cb</code> when STDIN_FILENO has become, well
857readable, but only once. Since it is likely line-buffered, you could 946readable, but only once. Since it is likely line-buffered, you could
858attempt to read a whole line in the callback:</p> 947attempt to read a whole line in the callback.</p>
859<pre> static void 948<pre> static void
860 stdin_readable_cb (struct ev_loop *loop, struct ev_io *w, int revents) 949 stdin_readable_cb (struct ev_loop *loop, struct ev_io *w, int revents)
861 { 950 {
862 ev_io_stop (loop, w); 951 ev_io_stop (loop, w);
863 .. read from stdin here (or from w-&gt;fd) and haqndle any I/O errors 952 .. read from stdin here (or from w-&gt;fd) and haqndle any I/O errors
… …
912 </dd> 1001 </dd>
913 <dt>ev_timer_again (loop)</dt> 1002 <dt>ev_timer_again (loop)</dt>
914 <dd> 1003 <dd>
915 <p>This will act as if the timer timed out and restart it again if it is 1004 <p>This will act as if the timer timed out and restart it again if it is
916repeating. The exact semantics are:</p> 1005repeating. The exact semantics are:</p>
1006 <p>If the timer is pending, its pending status is cleared.</p>
917 <p>If the timer is started but nonrepeating, stop it.</p> 1007 <p>If the timer is started but nonrepeating, stop it (as if it timed out).</p>
918 <p>If the timer is repeating, either start it if necessary (with the repeat 1008 <p>If the timer is repeating, either start it if necessary (with the
919value), or reset the running timer to the repeat value.</p> 1009<code>repeat</code> value), or reset the running timer to the <code>repeat</code> value.</p>
920 <p>This sounds a bit complicated, but here is a useful and typical 1010 <p>This sounds a bit complicated, but here is a useful and typical
921example: Imagine you have a tcp connection and you want a so-called 1011example: Imagine you have a tcp connection and you want a so-called idle
922idle timeout, that is, you want to be called when there have been, 1012timeout, that is, you want to be called when there have been, say, 60
923say, 60 seconds of inactivity on the socket. The easiest way to do 1013seconds of inactivity on the socket. The easiest way to do this is to
924this is to configure an <code>ev_timer</code> with <code>after</code>=<code>repeat</code>=<code>60</code> and calling 1014configure an <code>ev_timer</code> with a <code>repeat</code> value of <code>60</code> and then call
925<code>ev_timer_again</code> each time you successfully read or write some data. If 1015<code>ev_timer_again</code> each time you successfully read or write some data. If
926you go into an idle state where you do not expect data to travel on the 1016you go into an idle state where you do not expect data to travel on the
927socket, you can stop the timer, and again will automatically restart it if 1017socket, you can <code>ev_timer_stop</code> the timer, and <code>ev_timer_again</code> will
928need be.</p> 1018automatically restart it if need be.</p>
929 <p>You can also ignore the <code>after</code> value and <code>ev_timer_start</code> altogether 1019 <p>That means you can ignore the <code>after</code> value and <code>ev_timer_start</code>
930and only ever use the <code>repeat</code> value:</p> 1020altogether and only ever use the <code>repeat</code> value and <code>ev_timer_again</code>:</p>
931<pre> ev_timer_init (timer, callback, 0., 5.); 1021<pre> ev_timer_init (timer, callback, 0., 5.);
932 ev_timer_again (loop, timer); 1022 ev_timer_again (loop, timer);
933 ... 1023 ...
934 timer-&gt;again = 17.; 1024 timer-&gt;again = 17.;
935 ev_timer_again (loop, timer); 1025 ev_timer_again (loop, timer);
936 ... 1026 ...
937 timer-&gt;again = 10.; 1027 timer-&gt;again = 10.;
938 ev_timer_again (loop, timer); 1028 ev_timer_again (loop, timer);
939 1029
940</pre> 1030</pre>
941 <p>This is more efficient then stopping/starting the timer eahc time you want 1031 <p>This is more slightly efficient then stopping/starting the timer each time
942to modify its timeout value.</p> 1032you want to modify its timeout value.</p>
943 </dd> 1033 </dd>
944 <dt>ev_tstamp repeat [read-write]</dt> 1034 <dt>ev_tstamp repeat [read-write]</dt>
945 <dd> 1035 <dd>
946 <p>The current <code>repeat</code> value. Will be used each time the watcher times out 1036 <p>The current <code>repeat</code> value. Will be used each time the watcher times out
947or <code>ev_timer_again</code> is called and determines the next timeout (if any), 1037or <code>ev_timer_again</code> is called and determines the next timeout (if any),
948which is also when any modifications are taken into account.</p> 1038which is also when any modifications are taken into account.</p>
949 </dd> 1039 </dd>
950</dl> 1040</dl>
951<p>Example: create a timer that fires after 60 seconds.</p> 1041<p>Example: Create a timer that fires after 60 seconds.</p>
952<pre> static void 1042<pre> static void
953 one_minute_cb (struct ev_loop *loop, struct ev_timer *w, int revents) 1043 one_minute_cb (struct ev_loop *loop, struct ev_timer *w, int revents)
954 { 1044 {
955 .. one minute over, w is actually stopped right here 1045 .. one minute over, w is actually stopped right here
956 } 1046 }
… …
958 struct ev_timer mytimer; 1048 struct ev_timer mytimer;
959 ev_timer_init (&amp;mytimer, one_minute_cb, 60., 0.); 1049 ev_timer_init (&amp;mytimer, one_minute_cb, 60., 0.);
960 ev_timer_start (loop, &amp;mytimer); 1050 ev_timer_start (loop, &amp;mytimer);
961 1051
962</pre> 1052</pre>
963<p>Example: create a timeout timer that times out after 10 seconds of 1053<p>Example: Create a timeout timer that times out after 10 seconds of
964inactivity.</p> 1054inactivity.</p>
965<pre> static void 1055<pre> static void
966 timeout_cb (struct ev_loop *loop, struct ev_timer *w, int revents) 1056 timeout_cb (struct ev_loop *loop, struct ev_timer *w, int revents)
967 { 1057 {
968 .. ten seconds without any activity 1058 .. ten seconds without any activity
… …
1084 <p>The current reschedule callback, or <code>0</code>, if this functionality is 1174 <p>The current reschedule callback, or <code>0</code>, if this functionality is
1085switched off. Can be changed any time, but changes only take effect when 1175switched off. Can be changed any time, but changes only take effect when
1086the periodic timer fires or <code>ev_periodic_again</code> is being called.</p> 1176the periodic timer fires or <code>ev_periodic_again</code> is being called.</p>
1087 </dd> 1177 </dd>
1088</dl> 1178</dl>
1089<p>Example: call a callback every hour, or, more precisely, whenever the 1179<p>Example: Call a callback every hour, or, more precisely, whenever the
1090system clock is divisible by 3600. The callback invocation times have 1180system clock is divisible by 3600. The callback invocation times have
1091potentially a lot of jittering, but good long-term stability.</p> 1181potentially a lot of jittering, but good long-term stability.</p>
1092<pre> static void 1182<pre> static void
1093 clock_cb (struct ev_loop *loop, struct ev_io *w, int revents) 1183 clock_cb (struct ev_loop *loop, struct ev_io *w, int revents)
1094 { 1184 {
… …
1098 struct ev_periodic hourly_tick; 1188 struct ev_periodic hourly_tick;
1099 ev_periodic_init (&amp;hourly_tick, clock_cb, 0., 3600., 0); 1189 ev_periodic_init (&amp;hourly_tick, clock_cb, 0., 3600., 0);
1100 ev_periodic_start (loop, &amp;hourly_tick); 1190 ev_periodic_start (loop, &amp;hourly_tick);
1101 1191
1102</pre> 1192</pre>
1103<p>Example: the same as above, but use a reschedule callback to do it:</p> 1193<p>Example: The same as above, but use a reschedule callback to do it:</p>
1104<pre> #include &lt;math.h&gt; 1194<pre> #include &lt;math.h&gt;
1105 1195
1106 static ev_tstamp 1196 static ev_tstamp
1107 my_scheduler_cb (struct ev_periodic *w, ev_tstamp now) 1197 my_scheduler_cb (struct ev_periodic *w, ev_tstamp now)
1108 { 1198 {
… …
1110 } 1200 }
1111 1201
1112 ev_periodic_init (&amp;hourly_tick, clock_cb, 0., 0., my_scheduler_cb); 1202 ev_periodic_init (&amp;hourly_tick, clock_cb, 0., 0., my_scheduler_cb);
1113 1203
1114</pre> 1204</pre>
1115<p>Example: call a callback every hour, starting now:</p> 1205<p>Example: Call a callback every hour, starting now:</p>
1116<pre> struct ev_periodic hourly_tick; 1206<pre> struct ev_periodic hourly_tick;
1117 ev_periodic_init (&amp;hourly_tick, clock_cb, 1207 ev_periodic_init (&amp;hourly_tick, clock_cb,
1118 fmod (ev_now (loop), 3600.), 3600., 0); 1208 fmod (ev_now (loop), 3600.), 3600., 0);
1119 ev_periodic_start (loop, &amp;hourly_tick); 1209 ev_periodic_start (loop, &amp;hourly_tick);
1120 1210
… …
1181 <dd> 1271 <dd>
1182 <p>The process exit/trace status caused by <code>rpid</code> (see your systems 1272 <p>The process exit/trace status caused by <code>rpid</code> (see your systems
1183<code>waitpid</code> and <code>sys/wait.h</code> documentation for details).</p> 1273<code>waitpid</code> and <code>sys/wait.h</code> documentation for details).</p>
1184 </dd> 1274 </dd>
1185</dl> 1275</dl>
1186<p>Example: try to exit cleanly on SIGINT and SIGTERM.</p> 1276<p>Example: Try to exit cleanly on SIGINT and SIGTERM.</p>
1187<pre> static void 1277<pre> static void
1188 sigint_cb (struct ev_loop *loop, struct ev_signal *w, int revents) 1278 sigint_cb (struct ev_loop *loop, struct ev_signal *w, int revents)
1189 { 1279 {
1190 ev_unloop (loop, EVUNLOOP_ALL); 1280 ev_unloop (loop, EVUNLOOP_ALL);
1191 } 1281 }
… …
1208<p>The path does not need to exist: changing from &quot;path exists&quot; to &quot;path does 1298<p>The path does not need to exist: changing from &quot;path exists&quot; to &quot;path does
1209not exist&quot; is a status change like any other. The condition &quot;path does 1299not exist&quot; is a status change like any other. The condition &quot;path does
1210not exist&quot; is signified by the <code>st_nlink</code> field being zero (which is 1300not exist&quot; is signified by the <code>st_nlink</code> field being zero (which is
1211otherwise always forced to be at least one) and all the other fields of 1301otherwise always forced to be at least one) and all the other fields of
1212the stat buffer having unspecified contents.</p> 1302the stat buffer having unspecified contents.</p>
1303<p>The path <i>should</i> be absolute and <i>must not</i> end in a slash. If it is
1304relative and your working directory changes, the behaviour is undefined.</p>
1213<p>Since there is no standard to do this, the portable implementation simply 1305<p>Since there is no standard to do this, the portable implementation simply
1214calls <code>stat (2)</code> regulalry on the path to see if it changed somehow. You 1306calls <code>stat (2)</code> regularly on the path to see if it changed somehow. You
1215can specify a recommended polling interval for this case. If you specify 1307can specify a recommended polling interval for this case. If you specify
1216a polling interval of <code>0</code> (highly recommended!) then a <i>suitable, 1308a polling interval of <code>0</code> (highly recommended!) then a <i>suitable,
1217unspecified default</i> value will be used (which you can expect to be around 1309unspecified default</i> value will be used (which you can expect to be around
1218five seconds, although this might change dynamically). Libev will also 1310five seconds, although this might change dynamically). Libev will also
1219impose a minimum interval which is currently around <code>0.1</code>, but thats 1311impose a minimum interval which is currently around <code>0.1</code>, but thats
1220usually overkill.</p> 1312usually overkill.</p>
1221<p>This watcher type is not meant for massive numbers of stat watchers, 1313<p>This watcher type is not meant for massive numbers of stat watchers,
1222as even with OS-supported change notifications, this can be 1314as even with OS-supported change notifications, this can be
1223resource-intensive.</p> 1315resource-intensive.</p>
1224<p>At the time of this writing, no specific OS backends are implemented, but 1316<p>At the time of this writing, only the Linux inotify interface is
1225if demand increases, at least a kqueue and inotify backend will be added.</p> 1317implemented (implementing kqueue support is left as an exercise for the
1318reader). Inotify will be used to give hints only and should not change the
1319semantics of <code>ev_stat</code> watchers, which means that libev sometimes needs
1320to fall back to regular polling again even with inotify, but changes are
1321usually detected immediately, and if the file exists there will be no
1322polling.</p>
1226<dl> 1323<dl>
1227 <dt>ev_stat_init (ev_stat *, callback, const char *path, ev_tstamp interval)</dt> 1324 <dt>ev_stat_init (ev_stat *, callback, const char *path, ev_tstamp interval)</dt>
1228 <dt>ev_stat_set (ev_stat *, const char *path, ev_tstamp interval)</dt> 1325 <dt>ev_stat_set (ev_stat *, const char *path, ev_tstamp interval)</dt>
1229 <dd> 1326 <dd>
1230 <p>Configures the watcher to wait for status changes of the given 1327 <p>Configures the watcher to wait for status changes of the given
… …
1293</pre> 1390</pre>
1294 1391
1295</div> 1392</div>
1296<h2 id="code_ev_idle_code_when_you_ve_got_no"><code>ev_idle</code> - when you've got nothing better to do...</h2> 1393<h2 id="code_ev_idle_code_when_you_ve_got_no"><code>ev_idle</code> - when you've got nothing better to do...</h2>
1297<div id="code_ev_idle_code_when_you_ve_got_no-2"> 1394<div id="code_ev_idle_code_when_you_ve_got_no-2">
1298<p>Idle watchers trigger events when there are no other events are pending 1395<p>Idle watchers trigger events when no other events of the same or higher
1299(prepare, check and other idle watchers do not count). That is, as long 1396priority are pending (prepare, check and other idle watchers do not
1300as your process is busy handling sockets or timeouts (or even signals, 1397count).</p>
1301imagine) it will not be triggered. But when your process is idle all idle 1398<p>That is, as long as your process is busy handling sockets or timeouts
1302watchers are being called again and again, once per event loop iteration - 1399(or even signals, imagine) of the same or higher priority it will not be
1400triggered. But when your process is idle (or only lower-priority watchers
1401are pending), the idle watchers are being called once per event loop
1303until stopped, that is, or your process receives more events and becomes 1402iteration - until stopped, that is, or your process receives more events
1304busy.</p> 1403and becomes busy again with higher priority stuff.</p>
1305<p>The most noteworthy effect is that as long as any idle watchers are 1404<p>The most noteworthy effect is that as long as any idle watchers are
1306active, the process will not block when waiting for new events.</p> 1405active, the process will not block when waiting for new events.</p>
1307<p>Apart from keeping your process non-blocking (which is a useful 1406<p>Apart from keeping your process non-blocking (which is a useful
1308effect on its own sometimes), idle watchers are a good place to do 1407effect on its own sometimes), idle watchers are a good place to do
1309&quot;pseudo-background processing&quot;, or delay processing stuff to after the 1408&quot;pseudo-background processing&quot;, or delay processing stuff to after the
… …
1314 <p>Initialises and configures the idle watcher - it has no parameters of any 1413 <p>Initialises and configures the idle watcher - it has no parameters of any
1315kind. There is a <code>ev_idle_set</code> macro, but using it is utterly pointless, 1414kind. There is a <code>ev_idle_set</code> macro, but using it is utterly pointless,
1316believe me.</p> 1415believe me.</p>
1317 </dd> 1416 </dd>
1318</dl> 1417</dl>
1319<p>Example: dynamically allocate an <code>ev_idle</code>, start it, and in the 1418<p>Example: Dynamically allocate an <code>ev_idle</code> watcher, start it, and in the
1320callback, free it. Alos, use no error checking, as usual.</p> 1419callback, free it. Also, use no error checking, as usual.</p>
1321<pre> static void 1420<pre> static void
1322 idle_cb (struct ev_loop *loop, struct ev_idle *w, int revents) 1421 idle_cb (struct ev_loop *loop, struct ev_idle *w, int revents)
1323 { 1422 {
1324 free (w); 1423 free (w);
1325 // now do something you wanted to do when the program has 1424 // now do something you wanted to do when the program has
… …
1399 1498
1400 // create io watchers for each fd and a timer before blocking 1499 // create io watchers for each fd and a timer before blocking
1401 static void 1500 static void
1402 adns_prepare_cb (ev_loop *loop, ev_prepare *w, int revents) 1501 adns_prepare_cb (ev_loop *loop, ev_prepare *w, int revents)
1403 { 1502 {
1404 int timeout = 3600000;truct pollfd fds [nfd]; 1503 int timeout = 3600000;
1504 struct pollfd fds [nfd];
1405 // actual code will need to loop here and realloc etc. 1505 // actual code will need to loop here and realloc etc.
1406 adns_beforepoll (ads, fds, &amp;nfd, &amp;timeout, timeval_from (ev_time ())); 1506 adns_beforepoll (ads, fds, &amp;nfd, &amp;timeout, timeval_from (ev_time ()));
1407 1507
1408 /* the callback is illegal, but won't be called as we stop during check */ 1508 /* the callback is illegal, but won't be called as we stop during check */
1409 ev_timer_init (&amp;tw, 0, timeout * 1e-3); 1509 ev_timer_init (&amp;tw, 0, timeout * 1e-3);
… …
1550 1650
1551 1651
1552 1652
1553 1653
1554</div> 1654</div>
1555<h1 id="OTHER_FUNCTIONS">OTHER FUNCTIONS</h1><p><a href="#TOP" class="toplink">Top</a></p> 1655<h1 id="OTHER_FUNCTIONS">OTHER FUNCTIONS</h1>
1556<div id="OTHER_FUNCTIONS_CONTENT"> 1656<div id="OTHER_FUNCTIONS_CONTENT">
1557<p>There are some other functions of possible interest. Described. Here. Now.</p> 1657<p>There are some other functions of possible interest. Described. Here. Now.</p>
1558<dl> 1658<dl>
1559 <dt>ev_once (loop, int fd, int events, ev_tstamp timeout, callback)</dt> 1659 <dt>ev_once (loop, int fd, int events, ev_tstamp timeout, callback)</dt>
1560 <dd> 1660 <dd>
… …
1607 1707
1608 1708
1609 1709
1610 1710
1611</div> 1711</div>
1612<h1 id="LIBEVENT_EMULATION">LIBEVENT EMULATION</h1><p><a href="#TOP" class="toplink">Top</a></p> 1712<h1 id="LIBEVENT_EMULATION">LIBEVENT EMULATION</h1>
1613<div id="LIBEVENT_EMULATION_CONTENT"> 1713<div id="LIBEVENT_EMULATION_CONTENT">
1614<p>Libev offers a compatibility emulation layer for libevent. It cannot 1714<p>Libev offers a compatibility emulation layer for libevent. It cannot
1615emulate the internals of libevent, so here are some usage hints:</p> 1715emulate the internals of libevent, so here are some usage hints:</p>
1616<dl> 1716<dl>
1617 <dt>* Use it by including &lt;event.h&gt;, as usual.</dt> 1717 <dt>* Use it by including &lt;event.h&gt;, as usual.</dt>
… …
1627 <dt>* The libev emulation is <i>not</i> ABI compatible to libevent, you need 1727 <dt>* The libev emulation is <i>not</i> ABI compatible to libevent, you need
1628to use the libev header file and library.</dt> 1728to use the libev header file and library.</dt>
1629</dl> 1729</dl>
1630 1730
1631</div> 1731</div>
1632<h1 id="C_SUPPORT">C++ SUPPORT</h1><p><a href="#TOP" class="toplink">Top</a></p> 1732<h1 id="C_SUPPORT">C++ SUPPORT</h1>
1633<div id="C_SUPPORT_CONTENT"> 1733<div id="C_SUPPORT_CONTENT">
1634<p>Libev comes with some simplistic wrapper classes for C++ that mainly allow 1734<p>Libev comes with some simplistic wrapper classes for C++ that mainly allow
1635you to use some convinience methods to start/stop watchers and also change 1735you to use some convinience methods to start/stop watchers and also change
1636the callback model to a model using method callbacks on objects.</p> 1736the callback model to a model using method callbacks on objects.</p>
1637<p>To use it,</p> 1737<p>To use it,</p>
1638<pre> #include &lt;ev++.h&gt; 1738<pre> #include &lt;ev++.h&gt;
1639 1739
1640</pre> 1740</pre>
1641<p>(it is not installed by default). This automatically includes <cite>ev.h</cite> 1741<p>This automatically includes <cite>ev.h</cite> and puts all of its definitions (many
1642and puts all of its definitions (many of them macros) into the global 1742of them macros) into the global namespace. All C++ specific things are
1643namespace. All C++ specific things are put into the <code>ev</code> namespace.</p> 1743put into the <code>ev</code> namespace. It should support all the same embedding
1644<p>It should support all the same embedding options as <cite>ev.h</cite>, most notably 1744options as <cite>ev.h</cite>, most notably <code>EV_MULTIPLICITY</code>.</p>
1645<code>EV_MULTIPLICITY</code>.</p> 1745<p>Care has been taken to keep the overhead low. The only data member the C++
1746classes add (compared to plain C-style watchers) is the event loop pointer
1747that the watcher is associated with (or no additional members at all if
1748you disable <code>EV_MULTIPLICITY</code> when embedding libev).</p>
1749<p>Currently, functions, and static and non-static member functions can be
1750used as callbacks. Other types should be easy to add as long as they only
1751need one additional pointer for context. If you need support for other
1752types of functors please contact the author (preferably after implementing
1753it).</p>
1646<p>Here is a list of things available in the <code>ev</code> namespace:</p> 1754<p>Here is a list of things available in the <code>ev</code> namespace:</p>
1647<dl> 1755<dl>
1648 <dt><code>ev::READ</code>, <code>ev::WRITE</code> etc.</dt> 1756 <dt><code>ev::READ</code>, <code>ev::WRITE</code> etc.</dt>
1649 <dd> 1757 <dd>
1650 <p>These are just enum values with the same values as the <code>EV_READ</code> etc. 1758 <p>These are just enum values with the same values as the <code>EV_READ</code> etc.
… …
1661which is called <code>ev::sig</code> to avoid clashes with the <code>signal</code> macro 1769which is called <code>ev::sig</code> to avoid clashes with the <code>signal</code> macro
1662defines by many implementations.</p> 1770defines by many implementations.</p>
1663 <p>All of those classes have these methods:</p> 1771 <p>All of those classes have these methods:</p>
1664 <p> 1772 <p>
1665 <dl> 1773 <dl>
1666 <dt>ev::TYPE::TYPE (object *, object::method *)</dt> 1774 <dt>ev::TYPE::TYPE ()</dt>
1667 <dt>ev::TYPE::TYPE (object *, object::method *, struct ev_loop *)</dt> 1775 <dt>ev::TYPE::TYPE (struct ev_loop *)</dt>
1668 <dt>ev::TYPE::~TYPE</dt> 1776 <dt>ev::TYPE::~TYPE</dt>
1669 <dd> 1777 <dd>
1670 <p>The constructor takes a pointer to an object and a method pointer to 1778 <p>The constructor (optionally) takes an event loop to associate the watcher
1671the event handler callback to call in this class. The constructor calls 1779with. If it is omitted, it will use <code>EV_DEFAULT</code>.</p>
1672<code>ev_init</code> for you, which means you have to call the <code>set</code> method 1780 <p>The constructor calls <code>ev_init</code> for you, which means you have to call the
1673before starting it. If you do not specify a loop then the constructor 1781<code>set</code> method before starting it.</p>
1674automatically associates the default loop with this watcher.</p> 1782 <p>It will not set a callback, however: You have to call the templated <code>set</code>
1783method to set a callback before you can start the watcher.</p>
1784 <p>(The reason why you have to use a method is a limitation in C++ which does
1785not allow explicit template arguments for constructors).</p>
1675 <p>The destructor automatically stops the watcher if it is active.</p> 1786 <p>The destructor automatically stops the watcher if it is active.</p>
1787 </dd>
1788 <dt>w-&gt;set&lt;class, &amp;class::method&gt; (object *)</dt>
1789 <dd>
1790 <p>This method sets the callback method to call. The method has to have a
1791signature of <code>void (*)(ev_TYPE &amp;, int)</code>, it receives the watcher as
1792first argument and the <code>revents</code> as second. The object must be given as
1793parameter and is stored in the <code>data</code> member of the watcher.</p>
1794 <p>This method synthesizes efficient thunking code to call your method from
1795the C callback that libev requires. If your compiler can inline your
1796callback (i.e. it is visible to it at the place of the <code>set</code> call and
1797your compiler is good :), then the method will be fully inlined into the
1798thunking function, making it as fast as a direct C callback.</p>
1799 <p>Example: simple class declaration and watcher initialisation</p>
1800<pre> struct myclass
1801 {
1802 void io_cb (ev::io &amp;w, int revents) { }
1803 }
1804
1805 myclass obj;
1806 ev::io iow;
1807 iow.set &lt;myclass, &amp;myclass::io_cb&gt; (&amp;obj);
1808
1809</pre>
1810 </dd>
1811 <dt>w-&gt;set (void (*function)(watcher &amp;w, int), void *data = 0)</dt>
1812 <dd>
1813 <p>Also sets a callback, but uses a static method or plain function as
1814callback. The optional <code>data</code> argument will be stored in the watcher's
1815<code>data</code> member and is free for you to use.</p>
1816 <p>See the method-<code>set</code> above for more details.</p>
1676 </dd> 1817 </dd>
1677 <dt>w-&gt;set (struct ev_loop *)</dt> 1818 <dt>w-&gt;set (struct ev_loop *)</dt>
1678 <dd> 1819 <dd>
1679 <p>Associates a different <code>struct ev_loop</code> with this watcher. You can only 1820 <p>Associates a different <code>struct ev_loop</code> with this watcher. You can only
1680do this when the watcher is inactive (and not pending either).</p> 1821do this when the watcher is inactive (and not pending either).</p>
1681 </dd> 1822 </dd>
1682 <dt>w-&gt;set ([args])</dt> 1823 <dt>w-&gt;set ([args])</dt>
1683 <dd> 1824 <dd>
1684 <p>Basically the same as <code>ev_TYPE_set</code>, with the same args. Must be 1825 <p>Basically the same as <code>ev_TYPE_set</code>, with the same args. Must be
1685called at least once. Unlike the C counterpart, an active watcher gets 1826called at least once. Unlike the C counterpart, an active watcher gets
1686automatically stopped and restarted.</p> 1827automatically stopped and restarted when reconfiguring it with this
1828method.</p>
1687 </dd> 1829 </dd>
1688 <dt>w-&gt;start ()</dt> 1830 <dt>w-&gt;start ()</dt>
1689 <dd> 1831 <dd>
1690 <p>Starts the watcher. Note that there is no <code>loop</code> argument as the 1832 <p>Starts the watcher. Note that there is no <code>loop</code> argument, as the
1691constructor already takes the loop.</p> 1833constructor already stores the event loop.</p>
1692 </dd> 1834 </dd>
1693 <dt>w-&gt;stop ()</dt> 1835 <dt>w-&gt;stop ()</dt>
1694 <dd> 1836 <dd>
1695 <p>Stops the watcher if it is active. Again, no <code>loop</code> argument.</p> 1837 <p>Stops the watcher if it is active. Again, no <code>loop</code> argument.</p>
1696 </dd> 1838 </dd>
… …
1720 1862
1721 myclass (); 1863 myclass ();
1722 } 1864 }
1723 1865
1724 myclass::myclass (int fd) 1866 myclass::myclass (int fd)
1725 : io (this, &amp;myclass::io_cb),
1726 idle (this, &amp;myclass::idle_cb)
1727 { 1867 {
1868 io .set &lt;myclass, &amp;myclass::io_cb &gt; (this);
1869 idle.set &lt;myclass, &amp;myclass::idle_cb&gt; (this);
1870
1728 io.start (fd, ev::READ); 1871 io.start (fd, ev::READ);
1729 } 1872 }
1730 1873
1731 1874
1732 1875
1733 1876
1734</pre> 1877</pre>
1735 1878
1736</div> 1879</div>
1737<h1 id="MACRO_MAGIC">MACRO MAGIC</h1><p><a href="#TOP" class="toplink">Top</a></p> 1880<h1 id="MACRO_MAGIC">MACRO MAGIC</h1>
1738<div id="MACRO_MAGIC_CONTENT"> 1881<div id="MACRO_MAGIC_CONTENT">
1739<p>Libev can be compiled with a variety of options, the most fundemantal is 1882<p>Libev can be compiled with a variety of options, the most fundemantal is
1740<code>EV_MULTIPLICITY</code>. This option determines wether (most) functions and 1883<code>EV_MULTIPLICITY</code>. This option determines whether (most) functions and
1741callbacks have an initial <code>struct ev_loop *</code> argument.</p> 1884callbacks have an initial <code>struct ev_loop *</code> argument.</p>
1742<p>To make it easier to write programs that cope with either variant, the 1885<p>To make it easier to write programs that cope with either variant, the
1743following macros are defined:</p> 1886following macros are defined:</p>
1744<dl> 1887<dl>
1745 <dt><code>EV_A</code>, <code>EV_A_</code></dt> 1888 <dt><code>EV_A</code>, <code>EV_A_</code></dt>
… …
1774 <dd> 1917 <dd>
1775 <p>Similar to the other two macros, this gives you the value of the default 1918 <p>Similar to the other two macros, this gives you the value of the default
1776loop, if multiple loops are supported (&quot;ev loop default&quot;).</p> 1919loop, if multiple loops are supported (&quot;ev loop default&quot;).</p>
1777 </dd> 1920 </dd>
1778</dl> 1921</dl>
1779<p>Example: Declare and initialise a check watcher, working regardless of 1922<p>Example: Declare and initialise a check watcher, utilising the above
1780wether multiple loops are supported or not.</p> 1923macros so it will work regardless of whether multiple loops are supported
1924or not.</p>
1781<pre> static void 1925<pre> static void
1782 check_cb (EV_P_ ev_timer *w, int revents) 1926 check_cb (EV_P_ ev_timer *w, int revents)
1783 { 1927 {
1784 ev_check_stop (EV_A_ w); 1928 ev_check_stop (EV_A_ w);
1785 } 1929 }
… …
1787 ev_check check; 1931 ev_check check;
1788 ev_check_init (&amp;check, check_cb); 1932 ev_check_init (&amp;check, check_cb);
1789 ev_check_start (EV_DEFAULT_ &amp;check); 1933 ev_check_start (EV_DEFAULT_ &amp;check);
1790 ev_loop (EV_DEFAULT_ 0); 1934 ev_loop (EV_DEFAULT_ 0);
1791 1935
1792
1793
1794
1795</pre> 1936</pre>
1796 1937
1797</div> 1938</div>
1798<h1 id="EMBEDDING">EMBEDDING</h1><p><a href="#TOP" class="toplink">Top</a></p> 1939<h1 id="EMBEDDING">EMBEDDING</h1>
1799<div id="EMBEDDING_CONTENT"> 1940<div id="EMBEDDING_CONTENT">
1800<p>Libev can (and often is) directly embedded into host 1941<p>Libev can (and often is) directly embedded into host
1801applications. Examples of applications that embed it include the Deliantra 1942applications. Examples of applications that embed it include the Deliantra
1802Game Server, the EV perl module, the GNU Virtual Private Ethernet (gvpe) 1943Game Server, the EV perl module, the GNU Virtual Private Ethernet (gvpe)
1803and rxvt-unicode.</p> 1944and rxvt-unicode.</p>
… …
1840 ev_vars.h 1981 ev_vars.h
1841 ev_wrap.h 1982 ev_wrap.h
1842 1983
1843 ev_win32.c required on win32 platforms only 1984 ev_win32.c required on win32 platforms only
1844 1985
1845 ev_select.c only when select backend is enabled (which is by default) 1986 ev_select.c only when select backend is enabled (which is enabled by default)
1846 ev_poll.c only when poll backend is enabled (disabled by default) 1987 ev_poll.c only when poll backend is enabled (disabled by default)
1847 ev_epoll.c only when the epoll backend is enabled (disabled by default) 1988 ev_epoll.c only when the epoll backend is enabled (disabled by default)
1848 ev_kqueue.c only when the kqueue backend is enabled (disabled by default) 1989 ev_kqueue.c only when the kqueue backend is enabled (disabled by default)
1849 ev_port.c only when the solaris port backend is enabled (disabled by default) 1990 ev_port.c only when the solaris port backend is enabled (disabled by default)
1850 1991
… …
1977 </dd> 2118 </dd>
1978 <dt>EV_USE_DEVPOLL</dt> 2119 <dt>EV_USE_DEVPOLL</dt>
1979 <dd> 2120 <dd>
1980 <p>reserved for future expansion, works like the USE symbols above.</p> 2121 <p>reserved for future expansion, works like the USE symbols above.</p>
1981 </dd> 2122 </dd>
2123 <dt>EV_USE_INOTIFY</dt>
2124 <dd>
2125 <p>If defined to be <code>1</code>, libev will compile in support for the Linux inotify
2126interface to speed up <code>ev_stat</code> watchers. Its actual availability will
2127be detected at runtime.</p>
2128 </dd>
1982 <dt>EV_H</dt> 2129 <dt>EV_H</dt>
1983 <dd> 2130 <dd>
1984 <p>The name of the <cite>ev.h</cite> header file used to include it. The default if 2131 <p>The name of the <cite>ev.h</cite> header file used to include it. The default if
1985undefined is <code>&lt;ev.h&gt;</code> in <cite>event.h</cite> and <code>&quot;ev.h&quot;</code> in <cite>ev.c</cite>. This 2132undefined is <code>&lt;ev.h&gt;</code> in <cite>event.h</cite> and <code>&quot;ev.h&quot;</code> in <cite>ev.c</cite>. This
1986can be used to virtually rename the <cite>ev.h</cite> header file in case of conflicts.</p> 2133can be used to virtually rename the <cite>ev.h</cite> header file in case of conflicts.</p>
… …
2009will have the <code>struct ev_loop *</code> as first argument, and you can create 2156will have the <code>struct ev_loop *</code> as first argument, and you can create
2010additional independent event loops. Otherwise there will be no support 2157additional independent event loops. Otherwise there will be no support
2011for multiple event loops and there is no first event loop pointer 2158for multiple event loops and there is no first event loop pointer
2012argument. Instead, all functions act on the single default loop.</p> 2159argument. Instead, all functions act on the single default loop.</p>
2013 </dd> 2160 </dd>
2161 <dt>EV_MINPRI</dt>
2162 <dt>EV_MAXPRI</dt>
2163 <dd>
2164 <p>The range of allowed priorities. <code>EV_MINPRI</code> must be smaller or equal to
2165<code>EV_MAXPRI</code>, but otherwise there are no non-obvious limitations. You can
2166provide for more priorities by overriding those symbols (usually defined
2167to be <code>-2</code> and <code>2</code>, respectively).</p>
2168 <p>When doing priority-based operations, libev usually has to linearly search
2169all the priorities, so having many of them (hundreds) uses a lot of space
2170and time, so using the defaults of five priorities (-2 .. +2) is usually
2171fine.</p>
2172 <p>If your embedding app does not need any priorities, defining these both to
2173<code>0</code> will save some memory and cpu.</p>
2174 </dd>
2014 <dt>EV_PERIODIC_ENABLE</dt> 2175 <dt>EV_PERIODIC_ENABLE</dt>
2015 <dd> 2176 <dd>
2016 <p>If undefined or defined to be <code>1</code>, then periodic timers are supported. If 2177 <p>If undefined or defined to be <code>1</code>, then periodic timers are supported. If
2017defined to be <code>0</code>, then they are not. Disabling them saves a few kB of 2178defined to be <code>0</code>, then they are not. Disabling them saves a few kB of
2018code.</p> 2179code.</p>
2019 </dd> 2180 </dd>
2181 <dt>EV_IDLE_ENABLE</dt>
2182 <dd>
2183 <p>If undefined or defined to be <code>1</code>, then idle watchers are supported. If
2184defined to be <code>0</code>, then they are not. Disabling them saves a few kB of
2185code.</p>
2186 </dd>
2020 <dt>EV_EMBED_ENABLE</dt> 2187 <dt>EV_EMBED_ENABLE</dt>
2021 <dd> 2188 <dd>
2022 <p>If undefined or defined to be <code>1</code>, then embed watchers are supported. If 2189 <p>If undefined or defined to be <code>1</code>, then embed watchers are supported. If
2023defined to be <code>0</code>, then they are not.</p> 2190defined to be <code>0</code>, then they are not.</p>
2024 </dd> 2191 </dd>
… …
2041 <dt>EV_PID_HASHSIZE</dt> 2208 <dt>EV_PID_HASHSIZE</dt>
2042 <dd> 2209 <dd>
2043 <p><code>ev_child</code> watchers use a small hash table to distribute workload by 2210 <p><code>ev_child</code> watchers use a small hash table to distribute workload by
2044pid. The default size is <code>16</code> (or <code>1</code> with <code>EV_MINIMAL</code>), usually more 2211pid. The default size is <code>16</code> (or <code>1</code> with <code>EV_MINIMAL</code>), usually more
2045than enough. If you need to manage thousands of children you might want to 2212than enough. If you need to manage thousands of children you might want to
2046increase this value.</p> 2213increase this value (<i>must</i> be a power of two).</p>
2214 </dd>
2215 <dt>EV_INOTIFY_HASHSIZE</dt>
2216 <dd>
2217 <p><code>ev_staz</code> watchers use a small hash table to distribute workload by
2218inotify watch id. The default size is <code>16</code> (or <code>1</code> with <code>EV_MINIMAL</code>),
2219usually more than enough. If you need to manage thousands of <code>ev_stat</code>
2220watchers you might want to increase this value (<i>must</i> be a power of
2221two).</p>
2047 </dd> 2222 </dd>
2048 <dt>EV_COMMON</dt> 2223 <dt>EV_COMMON</dt>
2049 <dd> 2224 <dd>
2050 <p>By default, all watchers have a <code>void *data</code> member. By redefining 2225 <p>By default, all watchers have a <code>void *data</code> member. By redefining
2051this macro to a something else you can include more and other types of 2226this macro to a something else you can include more and other types of
… …
2078the <cite>libev/</cite> subdirectory and includes them in the <cite>EV/EVAPI.h</cite> (public 2253the <cite>libev/</cite> subdirectory and includes them in the <cite>EV/EVAPI.h</cite> (public
2079interface) and <cite>EV.xs</cite> (implementation) files. Only the <cite>EV.xs</cite> file 2254interface) and <cite>EV.xs</cite> (implementation) files. Only the <cite>EV.xs</cite> file
2080will be compiled. It is pretty complex because it provides its own header 2255will be compiled. It is pretty complex because it provides its own header
2081file.</p> 2256file.</p>
2082 <p>The usage in rxvt-unicode is simpler. It has a <cite>ev_cpp.h</cite> header file 2257 <p>The usage in rxvt-unicode is simpler. It has a <cite>ev_cpp.h</cite> header file
2083that everybody includes and which overrides some autoconf choices:</p> 2258that everybody includes and which overrides some configure choices:</p>
2259<pre> #define EV_MINIMAL 1
2084<pre> #define EV_USE_POLL 0 2260 #define EV_USE_POLL 0
2085 #define EV_MULTIPLICITY 0 2261 #define EV_MULTIPLICITY 0
2086 #define EV_PERIODICS 0 2262 #define EV_PERIODIC_ENABLE 0
2263 #define EV_STAT_ENABLE 0
2264 #define EV_FORK_ENABLE 0
2087 #define EV_CONFIG_H &lt;config.h&gt; 2265 #define EV_CONFIG_H &lt;config.h&gt;
2266 #define EV_MINPRI 0
2267 #define EV_MAXPRI 0
2088 2268
2089 #include &quot;ev++.h&quot; 2269 #include &quot;ev++.h&quot;
2090 2270
2091</pre> 2271</pre>
2092 <p>And a <cite>ev_cpp.C</cite> implementation file that contains libev proper and is compiled:</p> 2272 <p>And a <cite>ev_cpp.C</cite> implementation file that contains libev proper and is compiled:</p>
… …
2097 2277
2098 2278
2099</pre> 2279</pre>
2100 2280
2101</div> 2281</div>
2102<h1 id="COMPLEXITIES">COMPLEXITIES</h1><p><a href="#TOP" class="toplink">Top</a></p> 2282<h1 id="COMPLEXITIES">COMPLEXITIES</h1>
2103<div id="COMPLEXITIES_CONTENT"> 2283<div id="COMPLEXITIES_CONTENT">
2104 <p>In this section the complexities of (many of) the algorithms used inside 2284 <p>In this section the complexities of (many of) the algorithms used inside
2105libev will be explained. For complexity discussions about backends see the 2285libev will be explained. For complexity discussions about backends see the
2106documentation for <code>ev_default_init</code>.</p> 2286documentation for <code>ev_default_init</code>.</p>
2287 <p>All of the following are about amortised time: If an array needs to be
2288extended, libev needs to realloc and move the whole array, but this
2289happens asymptotically never with higher number of elements, so O(1) might
2290mean it might do a lengthy realloc operation in rare cases, but on average
2291it is much faster and asymptotically approaches constant time.</p>
2107 <p> 2292 <p>
2108 <dl> 2293 <dl>
2109 <dt>Starting and stopping timer/periodic watchers: O(log skipped_other_timers)</dt> 2294 <dt>Starting and stopping timer/periodic watchers: O(log skipped_other_timers)</dt>
2295 <dd>
2296 <p>This means that, when you have a watcher that triggers in one hour and
2297there are 100 watchers that would trigger before that then inserting will
2298have to skip those 100 watchers.</p>
2299 </dd>
2110 <dt>Changing timer/periodic watchers (by autorepeat, again): O(log skipped_other_timers)</dt> 2300 <dt>Changing timer/periodic watchers (by autorepeat, again): O(log skipped_other_timers)</dt>
2301 <dd>
2302 <p>That means that for changing a timer costs less than removing/adding them
2303as only the relative motion in the event queue has to be paid for.</p>
2304 </dd>
2111 <dt>Starting io/check/prepare/idle/signal/child watchers: O(1)</dt> 2305 <dt>Starting io/check/prepare/idle/signal/child watchers: O(1)</dt>
2306 <dd>
2307 <p>These just add the watcher into an array or at the head of a list.
2112 <dt>Stopping check/prepare/idle watchers: O(1)</dt> 2308=item Stopping check/prepare/idle watchers: O(1)</p>
2309 </dd>
2113 <dt>Stopping an io/signal/child watcher: O(number_of_watchers_for_this_(fd/signal/pid % 16))</dt> 2310 <dt>Stopping an io/signal/child watcher: O(number_of_watchers_for_this_(fd/signal/pid % EV_PID_HASHSIZE))</dt>
2311 <dd>
2312 <p>These watchers are stored in lists then need to be walked to find the
2313correct watcher to remove. The lists are usually short (you don't usually
2314have many watchers waiting for the same fd or signal).</p>
2315 </dd>
2114 <dt>Finding the next timer per loop iteration: O(1)</dt> 2316 <dt>Finding the next timer per loop iteration: O(1)</dt>
2115 <dt>Each change on a file descriptor per loop iteration: O(number_of_watchers_for_this_fd)</dt> 2317 <dt>Each change on a file descriptor per loop iteration: O(number_of_watchers_for_this_fd)</dt>
2318 <dd>
2319 <p>A change means an I/O watcher gets started or stopped, which requires
2320libev to recalculate its status (and possibly tell the kernel).</p>
2321 </dd>
2116 <dt>Activating one watcher: O(1)</dt> 2322 <dt>Activating one watcher: O(1)</dt>
2323 <dt>Priority handling: O(number_of_priorities)</dt>
2324 <dd>
2325 <p>Priorities are implemented by allocating some space for each
2326priority. When doing priority-based operations, libev usually has to
2327linearly search all the priorities.</p>
2328 </dd>
2117 </dl> 2329 </dl>
2118 </p> 2330 </p>
2119 2331
2120 2332
2121 2333
2122 2334
2123 2335
2124</div> 2336</div>
2125<h1 id="AUTHOR">AUTHOR</h1><p><a href="#TOP" class="toplink">Top</a></p> 2337<h1 id="AUTHOR">AUTHOR</h1>
2126<div id="AUTHOR_CONTENT"> 2338<div id="AUTHOR_CONTENT">
2127 <p>Marc Lehmann &lt;libev@schmorp.de&gt;.</p> 2339 <p>Marc Lehmann &lt;libev@schmorp.de&gt;.</p>
2128 2340
2129</div> 2341</div>
2130</div></body> 2342</div></body>

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