[ViewVC] Diff of: cvs/libev/ev.html

Comparing libev/ev.html (file contents):
Revision 1.59 by root, Wed Nov 28 17:32:24 2007 UTC vs.
Revision 1.63 by root, Thu Nov 29 20:05:59 2007 UTC

 <head>
 	<title>libev</title>
 	<meta name="description" content="Pod documentation for libev" />
 	<meta name="inputfile" content="&lt;standard input&gt;" />
 	<meta name="outputfile" content="&lt;standard output&gt;" />
-	<meta name="created" content="Wed Nov 28 18:32:11 2007" />
+	<meta name="created" content="Thu Nov 29 21:05:58 2007" />
 	<meta name="generator" content="Pod::Xhtml 1.57" />
 <link rel="stylesheet" href="http://res.tst.eu/pod.css"/></head>
 <body>
 <div class="pod">
 <!-- INDEX START -->
 or setgid) then libev will <i>not</i> look at the environment variable
 <code>LIBEV_FLAGS</code>. Otherwise (the default), this environment variable will
 override the flags completely if it is found in the environment. This is
 useful to try out specific backends to test their performance, or to work
 around bugs.</p>
+				</dd>
+				<dt><code>EVFLAG_FORKCHECK</code></dt>
+				<dd>
+					<p>Instead of calling <code>ev_default_fork</code> or <code>ev_loop_fork</code> manually after
+a fork, you can also make libev check for a fork in each iteration by
+enabling this flag.</p>
+					<p>This works by calling <code>getpid ()</code> on every iteration of the loop,
+and thus this might slow down your event loop if you do a lot of loop
+iterations and little real work, but is usually not noticable (on my
+Linux system for example, <code>getpid</code> is actually a simple 5-insn sequence
+without a syscall and thus <i>very</i> fast, but my Linux system also has
+<code>pthread_atfork</code> which is even faster).</p>
+					<p>The big advantage of this flag is that you can forget about fork (and
+forget about forgetting to tell libev about forking) when you use this
+flag.</p>
+					<p>This flag setting cannot be overriden or specified in the <code>LIBEV_FLAGS</code>
+environment variable.</p>
 				</dd>
 				<dt><code>EVBACKEND_SELECT</code>  (value 1, portable select backend)</dt>
 				<dd>
 					<p>This is your standard select(2) backend. Not <i>completely</i> standard, as
 libev tries to roll its own fd_set with no limits on the number of fds,
 	</dd>
 	<dt>ev_timer_again (loop)</dt>
 	<dd>
 		<p>This will act as if the timer timed out and restart it again if it is
 repeating. The exact semantics are:</p>
+		<p>If the timer is pending, its pending status is cleared.</p>
-		<p>If the timer is started but nonrepeating, stop it.</p>
+		<p>If the timer is started but nonrepeating, stop it (as if it timed out).</p>
-		<p>If the timer is repeating, either start it if necessary (with the repeat
+		<p>If the timer is repeating, either start it if necessary (with the
-value), or reset the running timer to the repeat value.</p>
+<code>repeat</code> value), or reset the running timer to the <code>repeat</code> value.</p>
 		<p>This sounds a bit complicated, but here is a useful and typical
-example: Imagine you have a tcp connection and you want a so-called
+example: Imagine you have a tcp connection and you want a so-called idle
-idle timeout, that is, you want to be called when there have been,
+timeout, that is, you want to be called when there have been, say, 60
-say, 60 seconds of inactivity on the socket. The easiest way to do
+seconds of inactivity on the socket. The easiest way to do this is to
-this is to configure an <code>ev_timer</code> with <code>after</code>=<code>repeat</code>=<code>60</code> and calling
+configure an <code>ev_timer</code> with a <code>repeat</code> value of <code>60</code> and then call
 <code>ev_timer_again</code> each time you successfully read or write some data. If
 you go into an idle state where you do not expect data to travel on the
-socket, you can stop the timer, and again will automatically restart it if
+socket, you can <code>ev_timer_stop</code> the timer, and <code>ev_timer_again</code> will
-need be.</p>
+automatically restart it if need be.</p>
-		<p>You can also ignore the <code>after</code> value and <code>ev_timer_start</code> altogether
+		<p>That means you can ignore the <code>after</code> value and <code>ev_timer_start</code>
-and only ever use the <code>repeat</code> value:</p>
+altogether and only ever use the <code>repeat</code> value and <code>ev_timer_again</code>:</p>
 <pre>   ev_timer_init (timer, callback, 0., 5.);
    ev_timer_again (loop, timer);
    ...
    timer-&gt;again = 17.;
    ev_timer_again (loop, timer);
    ...
    timer-&gt;again = 10.;
    ev_timer_again (loop, timer);
 </pre>
-		<p>This is more efficient then stopping/starting the timer eahc time you want
+		<p>This is more slightly efficient then stopping/starting the timer each time
-to modify its timeout value.</p>
+you want to modify its timeout value.</p>
 	</dd>
 	<dt>ev_tstamp repeat [read-write]</dt>
 	<dd>
 		<p>The current <code>repeat</code> value. Will be used each time the watcher times out
 or <code>ev_timer_again</code> is called and determines the next timeout (if any),
 <p>The path does not need to exist: changing from &quot;path exists&quot; to &quot;path does
 not exist&quot; is a status change like any other. The condition &quot;path does
 not exist&quot; is signified by the <code>st_nlink</code> field being zero (which is
 otherwise always forced to be at least one) and all the other fields of
 the stat buffer having unspecified contents.</p>
+<p>The path <i>should</i> be absolute and <i>must not</i> end in a slash. If it is
+relative and your working directory changes, the behaviour is undefined.</p>
 <p>Since there is no standard to do this, the portable implementation simply
 calls <code>stat (2)</code> regularly on the path to see if it changed somehow. You
 can specify a recommended polling interval for this case. If you specify
 a polling interval of <code>0</code> (highly recommended!) then a <i>suitable,
 unspecified default</i> value will be used (which you can expect to be around
 	<dd>
 		<p>Similar to the other two macros, this gives you the value of the default
 loop, if multiple loops are supported (&quot;ev loop default&quot;).</p>
 	</dd>
 </dl>
-<p>Example: Declare and initialise a check watcher, working regardless of
+<p>Example: Declare and initialise a check watcher, utilising the above
-wether multiple loops are supported or not.</p>
+macros so it will work regardless of wether multiple loops are supported
+or not.</p>
 <pre>  static void
   check_cb (EV_P_ ev_timer *w, int revents)
   {
     ev_check_stop (EV_A_ w);
   }
   ev_check check;
   ev_check_init (&amp;check, check_cb);
   ev_check_start (EV_DEFAULT_ &amp;check);
   ev_loop (EV_DEFAULT_ 0);
 </pre>
 </div>
 <h1 id="EMBEDDING">EMBEDDING</h1>
   ev_vars.h
   ev_wrap.h
   ev_win32.c      required on win32 platforms only
-  ev_select.c     only when select backend is enabled (which is by default)
+  ev_select.c     only when select backend is enabled (which is enabled by default)
   ev_poll.c       only when poll backend is enabled (disabled by default)
   ev_epoll.c      only when the epoll backend is enabled (disabled by default)
   ev_kqueue.c     only when the kqueue backend is enabled (disabled by default)
   ev_port.c       only when the solaris port backend is enabled (disabled by default)
 the <cite>libev/</cite> subdirectory and includes them in the <cite>EV/EVAPI.h</cite> (public
 interface) and <cite>EV.xs</cite> (implementation) files. Only the <cite>EV.xs</cite> file
 will be compiled. It is pretty complex because it provides its own header
 file.</p>
 		<p>The usage in rxvt-unicode is simpler. It has a <cite>ev_cpp.h</cite> header file
-that everybody includes and which overrides some autoconf choices:</p>
+that everybody includes and which overrides some configure choices:</p>
+<pre>  #define EV_MINIMAL 1
-<pre>  #define EV_USE_POLL 0
+  #define EV_USE_POLL 0
   #define EV_MULTIPLICITY 0
-  #define EV_PERIODICS 0
+  #define EV_PERIODIC_ENABLE 0
+  #define EV_STAT_ENABLE 0
+  #define EV_FORK_ENABLE 0
   #define EV_CONFIG_H &lt;config.h&gt;
+  #define EV_MINPRI 0
+  #define EV_MAXPRI 0
   #include &quot;ev++.h&quot;
 </pre>
 		<p>And a <cite>ev_cpp.C</cite> implementation file that contains libev proper and is compiled:</p>

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Comparing libev/ev.html (file contents): Revision 1.59 by root, Wed Nov 28 17:32:24 2007 UTC vs. Revision 1.63 by root, Thu Nov 29 20:05:59 2007 UTC

Diff Legend

Comparing libev/ev.html (file contents):
Revision 1.59 by root, Wed Nov 28 17:32:24 2007 UTC vs.
Revision 1.63 by root, Thu Nov 29 20:05:59 2007 UTC