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Revision 1.60 by root, Wed Nov 28 18:29:29 2007 UTC vs.
Revision 1.62 by root, Thu Nov 29 17:28:13 2007 UTC

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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="Wed Nov 28 19:29:25 2007" /> 9 <meta name="created" content="Thu Nov 29 18:28:02 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 -->
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325or setgid) then libev will <i>not</i> look at the environment variable 325or setgid) then libev will <i>not</i> look at the environment variable
326<code>LIBEV_FLAGS</code>. Otherwise (the default), this environment variable will 326<code>LIBEV_FLAGS</code>. Otherwise (the default), this environment variable will
327override the flags completely if it is found in the environment. This is 327override the flags completely if it is found in the environment. This is
328useful to try out specific backends to test their performance, or to work 328useful to try out specific backends to test their performance, or to work
329around bugs.</p> 329around bugs.</p>
330 </dd>
331 <dt><code>EVFLAG_FORKCHECK</code></dt>
332 <dd>
333 <p>Instead of calling <code>ev_default_fork</code> or <code>ev_loop_fork</code> manually after
334a fork, you can also make libev check for a fork in each iteration by
335enabling this flag.</p>
336 <p>This works by calling <code>getpid ()</code> on every iteration of the loop,
337and thus this might slow down your event loop if you do a lot of loop
338iterations and little real work, but is usually not noticable (on my
339Linux system for example, <code>getpid</code> is actually a simple 5-insn sequence
340without a syscall and thus <i>very</i> fast, but my Linux system also has
341<code>pthread_atfork</code> which is even faster).</p>
342 <p>The big advantage of this flag is that you can forget about fork (and
343forget about forgetting to tell libev about forking) when you use this
344flag.</p>
345 <p>This flag setting cannot be overriden or specified in the <code>LIBEV_FLAGS</code>
346environment variable.</p>
330 </dd> 347 </dd>
331 <dt><code>EVBACKEND_SELECT</code> (value 1, portable select backend)</dt> 348 <dt><code>EVBACKEND_SELECT</code> (value 1, portable select backend)</dt>
332 <dd> 349 <dd>
333 <p>This is your standard select(2) backend. Not <i>completely</i> standard, as 350 <p>This is your standard select(2) backend. Not <i>completely</i> standard, as
334libev tries to roll its own fd_set with no limits on the number of fds, 351libev tries to roll its own fd_set with no limits on the number of fds,
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952 </dd> 969 </dd>
953 <dt>ev_timer_again (loop)</dt> 970 <dt>ev_timer_again (loop)</dt>
954 <dd> 971 <dd>
955 <p>This will act as if the timer timed out and restart it again if it is 972 <p>This will act as if the timer timed out and restart it again if it is
956repeating. The exact semantics are:</p> 973repeating. The exact semantics are:</p>
974 <p>If the timer is pending, its pending status is cleared.</p>
957 <p>If the timer is started but nonrepeating, stop it.</p> 975 <p>If the timer is started but nonrepeating, stop it (as if it timed out).</p>
958 <p>If the timer is repeating, either start it if necessary (with the repeat 976 <p>If the timer is repeating, either start it if necessary (with the
959value), or reset the running timer to the repeat value.</p> 977<code>repeat</code> value), or reset the running timer to the <code>repeat</code> value.</p>
960 <p>This sounds a bit complicated, but here is a useful and typical 978 <p>This sounds a bit complicated, but here is a useful and typical
961example: Imagine you have a tcp connection and you want a so-called 979example: Imagine you have a tcp connection and you want a so-called idle
962idle timeout, that is, you want to be called when there have been, 980timeout, that is, you want to be called when there have been, say, 60
963say, 60 seconds of inactivity on the socket. The easiest way to do 981seconds of inactivity on the socket. The easiest way to do this is to
964this is to configure an <code>ev_timer</code> with <code>after</code>=<code>repeat</code>=<code>60</code> and calling 982configure an <code>ev_timer</code> with a <code>repeat</code> value of <code>60</code> and then call
965<code>ev_timer_again</code> each time you successfully read or write some data. If 983<code>ev_timer_again</code> each time you successfully read or write some data. If
966you go into an idle state where you do not expect data to travel on the 984you go into an idle state where you do not expect data to travel on the
967socket, you can stop the timer, and again will automatically restart it if 985socket, you can <code>ev_timer_stop</code> the timer, and <code>ev_timer_again</code> will
968need be.</p> 986automatically restart it if need be.</p>
969 <p>You can also ignore the <code>after</code> value and <code>ev_timer_start</code> altogether 987 <p>That means you can ignore the <code>after</code> value and <code>ev_timer_start</code>
970and only ever use the <code>repeat</code> value:</p> 988altogether and only ever use the <code>repeat</code> value and <code>ev_timer_again</code>:</p>
971<pre> ev_timer_init (timer, callback, 0., 5.); 989<pre> ev_timer_init (timer, callback, 0., 5.);
972 ev_timer_again (loop, timer); 990 ev_timer_again (loop, timer);
973 ... 991 ...
974 timer-&gt;again = 17.; 992 timer-&gt;again = 17.;
975 ev_timer_again (loop, timer); 993 ev_timer_again (loop, timer);
976 ... 994 ...
977 timer-&gt;again = 10.; 995 timer-&gt;again = 10.;
978 ev_timer_again (loop, timer); 996 ev_timer_again (loop, timer);
979 997
980</pre> 998</pre>
981 <p>This is more efficient then stopping/starting the timer eahc time you want 999 <p>This is more slightly efficient then stopping/starting the timer each time
982to modify its timeout value.</p> 1000you want to modify its timeout value.</p>
983 </dd> 1001 </dd>
984 <dt>ev_tstamp repeat [read-write]</dt> 1002 <dt>ev_tstamp repeat [read-write]</dt>
985 <dd> 1003 <dd>
986 <p>The current <code>repeat</code> value. Will be used each time the watcher times out 1004 <p>The current <code>repeat</code> value. Will be used each time the watcher times out
987or <code>ev_timer_again</code> is called and determines the next timeout (if any), 1005or <code>ev_timer_again</code> is called and determines the next timeout (if any),

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