<meta name="description" content="Pod documentation for libev" />
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- <meta name="created" content="Tue Nov 27 09:11:42 2007" />
+ <meta name="created" content="Tue Nov 27 20:23:27 2007" />
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<li><a href="#code_ev_idle_code_when_you_ve_got_no"><code>ev_idle</code> - when you've got nothing better to do...</a></li>
<li><a href="#code_ev_prepare_code_and_code_ev_che"><code>ev_prepare</code> and <code>ev_check</code> - customise your event loop!</a></li>
<li><a href="#code_ev_embed_code_when_one_backend_"><code>ev_embed</code> - when one backend isn't enough...</a></li>
+<li><a href="#code_ev_fork_code_the_audacity_to_re"><code>ev_fork</code> - the audacity to resume the event loop after a fork</a></li>
</ul>
</li>
<li><a href="#OTHER_FUNCTIONS">OTHER FUNCTIONS</a></li>
<li><a href="#LIBEVENT_EMULATION">LIBEVENT EMULATION</a></li>
<li><a href="#C_SUPPORT">C++ SUPPORT</a></li>
+<li><a href="#MACRO_MAGIC">MACRO MAGIC</a></li>
<li><a href="#EMBEDDING">EMBEDDING</a>
<ul><li><a href="#FILESETS">FILESETS</a>
<ul><li><a href="#CORE_EVENT_LOOP">CORE EVENT LOOP</a></li>
to the <code>double</code> type in C, and when you need to do any calculations on
it, you should treat it as such.</p>
-
-
-
-
</div>
<h1 id="GLOBAL_FUNCTIONS">GLOBAL FUNCTIONS</h1><p><a href="#TOP" class="toplink">Top</a></p>
<div id="GLOBAL_FUNCTIONS_CONTENT">
many watchers as they want, and all of them will be taken into account
(for example, a <code>ev_prepare</code> watcher might start an idle watcher to keep
<code>ev_loop</code> from blocking).</p>
+ </dd>
+ <dt><code>EV_EMBED</code></dt>
+ <dd>
+ <p>The embedded event loop specified in the <code>ev_embed</code> watcher needs attention.</p>
+ </dd>
+ <dt><code>EV_FORK</code></dt>
+ <dd>
+ <p>The event loop has been resumed in the child process after fork (see
+<code>ev_fork</code>).</p>
</dd>
<dt><code>EV_ERROR</code></dt>
<dd>
+</div>
+<h2 id="code_ev_fork_code_the_audacity_to_re"><code>ev_fork</code> - the audacity to resume the event loop after a fork</h2>
+<div id="code_ev_fork_code_the_audacity_to_re-2">
+<p>Fork watchers are called when a <code>fork ()</code> was detected (usually because
+whoever is a good citizen cared to tell libev about it by calling
+<code>ev_default_fork</code> or <code>ev_loop_fork</code>). The invocation is done before the
+event loop blocks next and before <code>ev_check</code> watchers are being called,
+and only in the child after the fork. If whoever good citizen calling
+<code>ev_default_fork</code> cheats and calls it in the wrong process, the fork
+handlers will be invoked, too, of course.</p>
+<dl>
+ <dt>ev_fork_init (ev_signal *, callback)</dt>
+ <dd>
+ <p>Initialises and configures the fork watcher - it has no parameters of any
+kind. There is a <code>ev_fork_set</code> macro, but using it is utterly pointless,
+believe me.</p>
+ </dd>
+</dl>
+
+
+
+
+
</div>
<h1 id="OTHER_FUNCTIONS">OTHER FUNCTIONS</h1><p><a href="#TOP" class="toplink">Top</a></p>
<div id="OTHER_FUNCTIONS_CONTENT">
<dd>
<p>Invokes <code>ev_embed_sweep</code>.</p>
</dd>
+ <dt>w->update () <code>ev::stat</code> only</dt>
+ <dd>
+ <p>Invokes <code>ev_stat_stat</code>.</p>
+ </dd>
</dl>
</p>
</dd>
io.start (fd, ev::READ);
}
+
+
+
+</pre>
+
+</div>
+<h1 id="MACRO_MAGIC">MACRO MAGIC</h1><p><a href="#TOP" class="toplink">Top</a></p>
+<div id="MACRO_MAGIC_CONTENT">
+<p>Libev can be compiled with a variety of options, the most fundemantal is
+<code>EV_MULTIPLICITY</code>. This option determines wether (most) functions and
+callbacks have an initial <code>struct ev_loop *</code> argument.</p>
+<p>To make it easier to write programs that cope with either variant, the
+following macros are defined:</p>
+<dl>
+ <dt><code>EV_A</code>, <code>EV_A_</code></dt>
+ <dd>
+ <p>This provides the loop <i>argument</i> for functions, if one is required ("ev
+loop argument"). The <code>EV_A</code> form is used when this is the sole argument,
+<code>EV_A_</code> is used when other arguments are following. Example:</p>
+<pre> ev_unref (EV_A);
+ ev_timer_add (EV_A_ watcher);
+ ev_loop (EV_A_ 0);
+
+</pre>
+ <p>It assumes the variable <code>loop</code> of type <code>struct ev_loop *</code> is in scope,
+which is often provided by the following macro.</p>
+ </dd>
+ <dt><code>EV_P</code>, <code>EV_P_</code></dt>
+ <dd>
+ <p>This provides the loop <i>parameter</i> for functions, if one is required ("ev
+loop parameter"). The <code>EV_P</code> form is used when this is the sole parameter,
+<code>EV_P_</code> is used when other parameters are following. Example:</p>
+<pre> // this is how ev_unref is being declared
+ static void ev_unref (EV_P);
+
+ // this is how you can declare your typical callback
+ static void cb (EV_P_ ev_timer *w, int revents)
+
+</pre>
+ <p>It declares a parameter <code>loop</code> of type <code>struct ev_loop *</code>, quite
+suitable for use with <code>EV_A</code>.</p>
+ </dd>
+ <dt><code>EV_DEFAULT</code>, <code>EV_DEFAULT_</code></dt>
+ <dd>
+ <p>Similar to the other two macros, this gives you the value of the default
+loop, if multiple loops are supported ("ev loop default").</p>
+ </dd>
+</dl>
+<p>Example: Declare and initialise a check watcher, working 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 (&check, check_cb);
+ ev_check_start (EV_DEFAULT_ &check);
+ ev_loop (EV_DEFAULT_ 0);
+
+
+
+
</pre>
</div>
<dt>EV_STAT_ENABLE</dt>
<dd>
<p>If undefined or defined to be <code>1</code>, then stat watchers are supported. If
+defined to be <code>0</code>, then they are not.</p>
+ </dd>
+ <dt>EV_FORK_ENABLE</dt>
+ <dd>
+ <p>If undefined or defined to be <code>1</code>, then fork watchers are supported. If
defined to be <code>0</code>, then they are not.</p>
</dd>
<dt>EV_MINIMAL</dt>
<p>If you need to shave off some kilobytes of code at the expense of some
speed, define this symbol to <code>1</code>. Currently only used for gcc to override
some inlining decisions, saves roughly 30% codesize of amd64.</p>
+ </dd>
+ <dt>EV_PID_HASHSIZE</dt>
+ <dd>
+ <p><code>ev_child</code> watchers use a small hash table to distribute workload by
+pid. The default size is <code>16</code> (or <code>1</code> with <code>EV_MINIMAL</code>), usually more
+than enough. If you need to manage thousands of children you might want to
+increase this value.</p>
</dd>
<dt>EV_COMMON</dt>
<dd>
projects / software / libev.git / blobdiff