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  1. 92
      ev.3
  2. 128
      ev.html
  3. 87
      ev.pod

92
ev.3

@ -134,13 +134,16 @@
libev \- a high performance full\-featured event loop written in C
.SH "SYNOPSIS"
.IX Header "SYNOPSIS"
.Vb 2
\& /* this is the only header you need */
.Vb 1
\& #include <ev.h>
.Ve
.SH "EXAMPLE PROGRAM"
.IX Header "EXAMPLE PROGRAM"
.Vb 1
\& #include <ev.h>
.Ve
.PP
.Vb 3
\& /* what follows is a fully working example program */
.Vb 2
\& ev_io stdin_watcher;
\& ev_timer timeout_watcher;
.Ve
@ -209,22 +212,27 @@ details of the event, and then hand it over to libev by \fIstarting\fR the
watcher.
.SH "FEATURES"
.IX Header "FEATURES"
Libev supports select, poll, the linux-specific epoll and the bsd-specific
kqueue mechanisms for file descriptor events, relative timers, absolute
timers with customised rescheduling, signal events, process status change
events (related to \s-1SIGCHLD\s0), and event watchers dealing with the event
loop mechanism itself (idle, prepare and check watchers). It also is quite
fast (see this benchmark comparing
it to libevent for example).
Libev supports \f(CW\*(C`select\*(C'\fR, \f(CW\*(C`poll\*(C'\fR, the linux-specific \f(CW\*(C`epoll\*(C'\fR, the
bsd-specific \f(CW\*(C`kqueue\*(C'\fR and the solaris-specific event port mechanisms
for file descriptor events (\f(CW\*(C`ev_io\*(C'\fR), relative timers (\f(CW\*(C`ev_timer\*(C'\fR),
absolute timers with customised rescheduling (\f(CW\*(C`ev_periodic\*(C'\fR), synchronous
signals (\f(CW\*(C`ev_signal\*(C'\fR), process status change events (\f(CW\*(C`ev_child\*(C'\fR), and
event watchers dealing with the event loop mechanism itself (\f(CW\*(C`ev_idle\*(C'\fR,
\&\f(CW\*(C`ev_embed\*(C'\fR, \f(CW\*(C`ev_prepare\*(C'\fR and \f(CW\*(C`ev_check\*(C'\fR watchers) as well as
file watchers (\f(CW\*(C`ev_stat\*(C'\fR) and even limited support for fork events
(\f(CW\*(C`ev_fork\*(C'\fR).
.PP
It also is quite fast (see this
benchmark comparing it to libevent
for example).
.SH "CONVENTIONS"
.IX Header "CONVENTIONS"
Libev is very configurable. In this manual the default configuration
will be described, which supports multiple event loops. For more info
about various configuration options please have a look at the file
\&\fI\s-1README\s0.embed\fR in the libev distribution. If libev was configured without
support for multiple event loops, then all functions taking an initial
argument of name \f(CW\*(C`loop\*(C'\fR (which is always of type \f(CW\*(C`struct ev_loop *\*(C'\fR)
will not have this argument.
Libev is very configurable. In this manual the default configuration will
be described, which supports multiple event loops. For more info about
various configuration options please have a look at \fB\s-1EMBED\s0\fR section in
this manual. If libev was configured without support for multiple event
loops, then all functions taking an initial argument of name \f(CW\*(C`loop\*(C'\fR
(which is always of type \f(CW\*(C`struct ev_loop *\*(C'\fR) will not have this argument.
.SH "TIME REPRESENTATION"
.IX Header "TIME REPRESENTATION"
Libev represents time as a single floating point number, representing the
@ -259,8 +267,8 @@ as this indicates an incompatible change. Minor versions are usually
compatible to older versions, so a larger minor version alone is usually
not a problem.
.Sp
Example: make sure we haven't accidentally been linked against the wrong
version:
Example: Make sure we haven't accidentally been linked against the wrong
version.
.Sp
.Vb 3
\& assert (("libev version mismatch",
@ -310,8 +318,8 @@ You could override this function in high-availability programs to, say,
free some memory if it cannot allocate memory, to use a special allocator,
or even to sleep a while and retry until some memory is available.
.Sp
Example: replace the libev allocator with one that waits a bit and then
retries: better than mine).
Example: Replace the libev allocator with one that waits a bit and then
retries).
.Sp
.Vb 6
\& static void *
@ -347,7 +355,7 @@ matter what, when it returns. That is, libev will generally retry the
requested operation, or, if the condition doesn't go away, do bad stuff
(such as abort).
.Sp
Example: do the same thing as libev does internally:
Example: This is basically the same thing that libev does internally, too.
.Sp
.Vb 6
\& static void
@ -506,7 +514,7 @@ always distinct from the default loop. Unlike the default loop, it cannot
handle signal and child watchers, and attempts to do so will be greeted by
undefined behaviour (or a failed assertion if assertions are enabled).
.Sp
Example: try to create a event loop that uses epoll and nothing else.
Example: Try to create a event loop that uses epoll and nothing else.
.Sp
.Vb 3
\& struct ev_loop *epoller = ev_loop_new (EVBACKEND_EPOLL | EVFLAG_NOENV);
@ -614,7 +622,7 @@ Here are the gory details of what \f(CW\*(C`ev_loop\*(C'\fR does:
\& were used, return, otherwise continue with step *.
.Ve
.Sp
Example: queue some jobs and then loop until no events are outsanding
Example: Queue some jobs and then loop until no events are outsanding
anymore.
.Sp
.Vb 4
@ -646,21 +654,21 @@ no event watchers registered by it are active. It is also an excellent
way to do this for generic recurring timers or from within third-party
libraries. Just remember to \fIunref after start\fR and \fIref before stop\fR.
.Sp
Example: create a signal watcher, but keep it from keeping \f(CW\*(C`ev_loop\*(C'\fR
Example: Create a signal watcher, but keep it from keeping \f(CW\*(C`ev_loop\*(C'\fR
running when nothing else is active.
.Sp
.Vb 4
\& struct dv_signal exitsig;
\& struct ev_signal exitsig;
\& ev_signal_init (&exitsig, sig_cb, SIGINT);
\& ev_signal_start (myloop, &exitsig);
\& evf_unref (myloop);
\& ev_signal_start (loop, &exitsig);
\& evf_unref (loop);
.Ve
.Sp
Example: for some weird reason, unregister the above signal handler again.
Example: For some weird reason, unregister the above signal handler again.
.Sp
.Vb 2
\& ev_ref (myloop);
\& ev_signal_stop (myloop, &exitsig);
\& ev_ref (loop);
\& ev_signal_stop (loop, &exitsig);
.Ve
.SH "ANATOMY OF A WATCHER"
.IX Header "ANATOMY OF A WATCHER"
@ -959,9 +967,9 @@ The file descriptor being watched.
.IX Item "int events [read-only]"
The events being watched.
.PP
Example: call \f(CW\*(C`stdin_readable_cb\*(C'\fR when \s-1STDIN_FILENO\s0 has become, well
Example: Call \f(CW\*(C`stdin_readable_cb\*(C'\fR when \s-1STDIN_FILENO\s0 has become, well
readable, but only once. Since it is likely line\-buffered, you could
attempt to read a whole line in the callback:
attempt to read a whole line in the callback.
.PP
.Vb 6
\& static void
@ -1063,7 +1071,7 @@ The current \f(CW\*(C`repeat\*(C'\fR value. Will be used each time the watcher t
or \f(CW\*(C`ev_timer_again\*(C'\fR is called and determines the next timeout (if any),
which is also when any modifications are taken into account.
.PP
Example: create a timer that fires after 60 seconds.
Example: Create a timer that fires after 60 seconds.
.PP
.Vb 5
\& static void
@ -1079,7 +1087,7 @@ Example: create a timer that fires after 60 seconds.
\& ev_timer_start (loop, &mytimer);
.Ve
.PP
Example: create a timeout timer that times out after 10 seconds of
Example: Create a timeout timer that times out after 10 seconds of
inactivity.
.PP
.Vb 5
@ -1214,7 +1222,7 @@ The current reschedule callback, or \f(CW0\fR, if this functionality is
switched off. Can be changed any time, but changes only take effect when
the periodic timer fires or \f(CW\*(C`ev_periodic_again\*(C'\fR is being called.
.PP
Example: call a callback every hour, or, more precisely, whenever the
Example: Call a callback every hour, or, more precisely, whenever the
system clock is divisible by 3600. The callback invocation times have
potentially a lot of jittering, but good long-term stability.
.PP
@ -1232,7 +1240,7 @@ potentially a lot of jittering, but good long-term stability.
\& ev_periodic_start (loop, &hourly_tick);
.Ve
.PP
Example: the same as above, but use a reschedule callback to do it:
Example: The same as above, but use a reschedule callback to do it:
.PP
.Vb 1
\& #include <math.h>
@ -1250,7 +1258,7 @@ Example: the same as above, but use a reschedule callback to do it:
\& ev_periodic_init (&hourly_tick, clock_cb, 0., 0., my_scheduler_cb);
.Ve
.PP
Example: call a callback every hour, starting now:
Example: Call a callback every hour, starting now:
.PP
.Vb 4
\& struct ev_periodic hourly_tick;
@ -1311,7 +1319,7 @@ The process id that detected a status change.
The process exit/trace status caused by \f(CW\*(C`rpid\*(C'\fR (see your systems
\&\f(CW\*(C`waitpid\*(C'\fR and \f(CW\*(C`sys/wait.h\*(C'\fR documentation for details).
.PP
Example: try to exit cleanly on \s-1SIGINT\s0 and \s-1SIGTERM\s0.
Example: Try to exit cleanly on \s-1SIGINT\s0 and \s-1SIGTERM\s0.
.PP
.Vb 5
\& static void
@ -1445,8 +1453,8 @@ Initialises and configures the idle watcher \- it has no parameters of any
kind. There is a \f(CW\*(C`ev_idle_set\*(C'\fR macro, but using it is utterly pointless,
believe me.
.PP
Example: dynamically allocate an \f(CW\*(C`ev_idle\*(C'\fR, start it, and in the
callback, free it. Alos, use no error checking, as usual.
Example: Dynamically allocate an \f(CW\*(C`ev_idle\*(C'\fR watcher, start it, and in the
callback, free it. Also, use no error checking, as usual.
.PP
.Vb 7
\& static void

128
ev.html

@ -6,7 +6,7 @@
<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="Tue Nov 27 21:14:27 2007" />
<meta name="created" content="Tue Nov 27 21:29:04 2007" />
<meta name="generator" content="Pod::Xhtml 1.57" />
<link rel="stylesheet" href="http://res.tst.eu/pod.css"/></head>
<body>
@ -16,6 +16,7 @@
<ul><li><a href="#NAME">NAME</a></li>
<li><a href="#SYNOPSIS">SYNOPSIS</a></li>
<li><a href="#EXAMPLE_PROGRAM">EXAMPLE PROGRAM</a></li>
<li><a href="#DESCRIPTION">DESCRIPTION</a></li>
<li><a href="#FEATURES">FEATURES</a></li>
<li><a href="#CONVENTIONS">CONVENTIONS</a></li>
@ -61,17 +62,22 @@
</ul><hr />
<!-- INDEX END -->
<h1 id="NAME">NAME</h1><p><a href="#TOP" class="toplink">Top</a></p>
<h1 id="NAME">NAME</h1>
<div id="NAME_CONTENT">
<p>libev - a high performance full-featured event loop written in C</p>
</div>
<h1 id="SYNOPSIS">SYNOPSIS</h1><p><a href="#TOP" class="toplink">Top</a></p>
<h1 id="SYNOPSIS">SYNOPSIS</h1>
<div id="SYNOPSIS_CONTENT">
<pre> /* this is the only header you need */
#include &lt;ev.h&gt;
<pre> #include &lt;ev.h&gt;
</pre>
</div>
<h1 id="EXAMPLE_PROGRAM">EXAMPLE PROGRAM</h1>
<div id="EXAMPLE_PROGRAM_CONTENT">
<pre> #include &lt;ev.h&gt;
/* what follows is a fully working example program */
ev_io stdin_watcher;
ev_timer timeout_watcher;
@ -113,7 +119,7 @@
</pre>
</div>
<h1 id="DESCRIPTION">DESCRIPTION</h1><p><a href="#TOP" class="toplink">Top</a></p>
<h1 id="DESCRIPTION">DESCRIPTION</h1>
<div id="DESCRIPTION_CONTENT">
<p>Libev is an event loop: you register interest in certain events (such as a
file descriptor being readable or a timeout occuring), and it will manage
@ -127,29 +133,33 @@ details of the event, and then hand it over to libev by <i>starting</i> the
watcher.</p>
</div>
<h1 id="FEATURES">FEATURES</h1><p><a href="#TOP" class="toplink">Top</a></p>
<h1 id="FEATURES">FEATURES</h1>
<div id="FEATURES_CONTENT">
<p>Libev supports select, poll, the linux-specific epoll and the bsd-specific
kqueue mechanisms for file descriptor events, relative timers, absolute
timers with customised rescheduling, signal events, process status change
events (related to SIGCHLD), and event watchers dealing with the event
loop mechanism itself (idle, prepare and check watchers). It also is quite
fast (see this <a href="http://libev.schmorp.de/bench.html">benchmark</a> comparing
it to libevent for example).</p>
<p>Libev supports <code>select</code>, <code>poll</code>, the linux-specific <code>epoll</code>, the
bsd-specific <code>kqueue</code> and the solaris-specific event port mechanisms
for file descriptor events (<code>ev_io</code>), relative timers (<code>ev_timer</code>),
absolute timers with customised rescheduling (<code>ev_periodic</code>), synchronous
signals (<code>ev_signal</code>), process status change events (<code>ev_child</code>), and
event watchers dealing with the event loop mechanism itself (<code>ev_idle</code>,
<code>ev_embed</code>, <code>ev_prepare</code> and <code>ev_check</code> watchers) as well as
file watchers (<code>ev_stat</code>) and even limited support for fork events
(<code>ev_fork</code>).</p>
<p>It also is quite fast (see this
<a href="http://libev.schmorp.de/bench.html">benchmark</a> comparing it to libevent
for example).</p>
</div>
<h1 id="CONVENTIONS">CONVENTIONS</h1><p><a href="#TOP" class="toplink">Top</a></p>
<h1 id="CONVENTIONS">CONVENTIONS</h1>
<div id="CONVENTIONS_CONTENT">
<p>Libev is very configurable. In this manual the default configuration
will be described, which supports multiple event loops. For more info
about various configuration options please have a look at the file
<cite>README.embed</cite> in the libev distribution. If libev was configured without
support for multiple event loops, then all functions taking an initial
argument of name <code>loop</code> (which is always of type <code>struct ev_loop *</code>)
will not have this argument.</p>
<p>Libev is very configurable. In this manual the default configuration will
be described, which supports multiple event loops. For more info about
various configuration options please have a look at <strong>EMBED</strong> section in
this manual. If libev was configured without support for multiple event
loops, then all functions taking an initial argument of name <code>loop</code>
(which is always of type <code>struct ev_loop *</code>) will not have this argument.</p>
</div>
<h1 id="TIME_REPRESENTATION">TIME REPRESENTATION</h1><p><a href="#TOP" class="toplink">Top</a></p>
<h1 id="TIME_REPRESENTATION">TIME REPRESENTATION</h1>
<div id="TIME_REPRESENTATION_CONTENT">
<p>Libev represents time as a single floating point number, representing the
(fractional) number of seconds since the (POSIX) epoch (somewhere near
@ -159,7 +169,7 @@ to the <code>double</code> type in C, and when you need to do any calculations o
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>
<h1 id="GLOBAL_FUNCTIONS">GLOBAL FUNCTIONS</h1>
<div id="GLOBAL_FUNCTIONS_CONTENT">
<p>These functions can be called anytime, even before initialising the
library in any way.</p>
@ -182,8 +192,8 @@ version of the library your program was compiled against.</p>
as this indicates an incompatible change. Minor versions are usually
compatible to older versions, so a larger minor version alone is usually
not a problem.</p>
<p>Example: make sure we haven't accidentally been linked against the wrong
version:</p>
<p>Example: Make sure we haven't accidentally been linked against the wrong
version.</p>
<pre> assert ((&quot;libev version mismatch&quot;,
ev_version_major () == EV_VERSION_MAJOR
&amp;&amp; ev_version_minor () &gt;= EV_VERSION_MINOR));
@ -231,8 +241,8 @@ action. The default is your system realloc function.</p>
<p>You could override this function in high-availability programs to, say,
free some memory if it cannot allocate memory, to use a special allocator,
or even to sleep a while and retry until some memory is available.</p>
<p>Example: replace the libev allocator with one that waits a bit and then
retries: better than mine).</p>
<p>Example: Replace the libev allocator with one that waits a bit and then
retries).</p>
<pre> static void *
persistent_realloc (void *ptr, size_t size)
{
@ -261,7 +271,7 @@ callback is set, then libev will expect it to remedy the sitution, no
matter what, when it returns. That is, libev will generally retry the
requested operation, or, if the condition doesn't go away, do bad stuff
(such as abort).</p>
<p>Example: do the same thing as libev does internally:</p>
<p>Example: This is basically the same thing that libev does internally, too.</p>
<pre> static void
fatal_error (const char *msg)
{
@ -277,7 +287,7 @@ requested operation, or, if the condition doesn't go away, do bad stuff
</dl>
</div>
<h1 id="FUNCTIONS_CONTROLLING_THE_EVENT_LOOP">FUNCTIONS CONTROLLING THE EVENT LOOP</h1><p><a href="#TOP" class="toplink">Top</a></p>
<h1 id="FUNCTIONS_CONTROLLING_THE_EVENT_LOOP">FUNCTIONS CONTROLLING THE EVENT LOOP</h1>
<div id="FUNCTIONS_CONTROLLING_THE_EVENT_LOOP-2">
<p>An event loop is described by a <code>struct ev_loop *</code>. The library knows two
types of such loops, the <i>default</i> loop, which supports signals and child
@ -407,7 +417,7 @@ event loop and only if you know the OS supports your types of fds):</p>
always distinct from the default loop. Unlike the default loop, it cannot
handle signal and child watchers, and attempts to do so will be greeted by
undefined behaviour (or a failed assertion if assertions are enabled).</p>
<p>Example: try to create a event loop that uses epoll and nothing else.</p>
<p>Example: Try to create a event loop that uses epoll and nothing else.</p>
<pre> struct ev_loop *epoller = ev_loop_new (EVBACKEND_EPOLL | EVFLAG_NOENV);
if (!epoller)
fatal (&quot;no epoll found here, maybe it hides under your chair&quot;);
@ -510,7 +520,7 @@ usually a better approach for this kind of thing.</p>
were used, return, otherwise continue with step *.
</pre>
<p>Example: queue some jobs and then loop until no events are outsanding
<p>Example: Queue some jobs and then loop until no events are outsanding
anymore.</p>
<pre> ... queue jobs here, make sure they register event watchers as long
... as they still have work to do (even an idle watcher will do..)
@ -539,17 +549,17 @@ visible to the libev user and should not keep <code>ev_loop</code> from exiting
no event watchers registered by it are active. It is also an excellent
way to do this for generic recurring timers or from within third-party
libraries. Just remember to <i>unref after start</i> and <i>ref before stop</i>.</p>
<p>Example: create a signal watcher, but keep it from keeping <code>ev_loop</code>
<p>Example: Create a signal watcher, but keep it from keeping <code>ev_loop</code>
running when nothing else is active.</p>
<pre> struct dv_signal exitsig;
<pre> struct ev_signal exitsig;
ev_signal_init (&amp;exitsig, sig_cb, SIGINT);
ev_signal_start (myloop, &amp;exitsig);
evf_unref (myloop);
ev_signal_start (loop, &amp;exitsig);
evf_unref (loop);
</pre>
<p>Example: for some weird reason, unregister the above signal handler again.</p>
<pre> ev_ref (myloop);
ev_signal_stop (myloop, &amp;exitsig);
<p>Example: For some weird reason, unregister the above signal handler again.</p>
<pre> ev_ref (loop);
ev_signal_stop (loop, &amp;exitsig);
</pre>
</dd>
@ -560,7 +570,7 @@ running when nothing else is active.</p>
</div>
<h1 id="ANATOMY_OF_A_WATCHER">ANATOMY OF A WATCHER</h1><p><a href="#TOP" class="toplink">Top</a></p>
<h1 id="ANATOMY_OF_A_WATCHER">ANATOMY OF A WATCHER</h1>
<div id="ANATOMY_OF_A_WATCHER_CONTENT">
<p>A watcher is a structure that you create and register to record your
interest in some event. For instance, if you want to wait for STDIN to
@ -783,7 +793,7 @@ have been omitted....</p>
</div>
<h1 id="WATCHER_TYPES">WATCHER TYPES</h1><p><a href="#TOP" class="toplink">Top</a></p>
<h1 id="WATCHER_TYPES">WATCHER TYPES</h1>
<div id="WATCHER_TYPES_CONTENT">
<p>This section describes each watcher in detail, but will not repeat
information given in the last section. Any initialisation/set macros,
@ -853,9 +863,9 @@ rceeive events for and events is either <code>EV_READ</code>, <code>EV_WRITE</co
<p>The events being watched.</p>
</dd>
</dl>
<p>Example: call <code>stdin_readable_cb</code> when STDIN_FILENO has become, well
<p>Example: Call <code>stdin_readable_cb</code> when STDIN_FILENO has become, well
readable, but only once. Since it is likely line-buffered, you could
attempt to read a whole line in the callback:</p>
attempt to read a whole line in the callback.</p>
<pre> static void
stdin_readable_cb (struct ev_loop *loop, struct ev_io *w, int revents)
{
@ -948,7 +958,7 @@ or <code>ev_timer_again</code> is called and determines the next timeout (if any
which is also when any modifications are taken into account.</p>
</dd>
</dl>
<p>Example: create a timer that fires after 60 seconds.</p>
<p>Example: Create a timer that fires after 60 seconds.</p>
<pre> static void
one_minute_cb (struct ev_loop *loop, struct ev_timer *w, int revents)
{
@ -960,7 +970,7 @@ which is also when any modifications are taken into account.</p>
ev_timer_start (loop, &amp;mytimer);
</pre>
<p>Example: create a timeout timer that times out after 10 seconds of
<p>Example: Create a timeout timer that times out after 10 seconds of
inactivity.</p>
<pre> static void
timeout_cb (struct ev_loop *loop, struct ev_timer *w, int revents)
@ -1086,7 +1096,7 @@ switched off. Can be changed any time, but changes only take effect when
the periodic timer fires or <code>ev_periodic_again</code> is being called.</p>
</dd>
</dl>
<p>Example: call a callback every hour, or, more precisely, whenever the
<p>Example: Call a callback every hour, or, more precisely, whenever the
system clock is divisible by 3600. The callback invocation times have
potentially a lot of jittering, but good long-term stability.</p>
<pre> static void
@ -1100,7 +1110,7 @@ potentially a lot of jittering, but good long-term stability.</p>
ev_periodic_start (loop, &amp;hourly_tick);
</pre>
<p>Example: the same as above, but use a reschedule callback to do it:</p>
<p>Example: The same as above, but use a reschedule callback to do it:</p>
<pre> #include &lt;math.h&gt;
static ev_tstamp
@ -1112,7 +1122,7 @@ potentially a lot of jittering, but good long-term stability.</p>
ev_periodic_init (&amp;hourly_tick, clock_cb, 0., 0., my_scheduler_cb);
</pre>
<p>Example: call a callback every hour, starting now:</p>
<p>Example: Call a callback every hour, starting now:</p>
<pre> struct ev_periodic hourly_tick;
ev_periodic_init (&amp;hourly_tick, clock_cb,
fmod (ev_now (loop), 3600.), 3600., 0);
@ -1183,7 +1193,7 @@ process causing the status change.</p>
<code>waitpid</code> and <code>sys/wait.h</code> documentation for details).</p>
</dd>
</dl>
<p>Example: try to exit cleanly on SIGINT and SIGTERM.</p>
<p>Example: Try to exit cleanly on SIGINT and SIGTERM.</p>
<pre> static void
sigint_cb (struct ev_loop *loop, struct ev_signal *w, int revents)
{
@ -1316,8 +1326,8 @@ kind. There is a <code>ev_idle_set</code> macro, but using it is utterly pointle
believe me.</p>
</dd>
</dl>
<p>Example: dynamically allocate an <code>ev_idle</code>, start it, and in the
callback, free it. Alos, use no error checking, as usual.</p>
<p>Example: Dynamically allocate an <code>ev_idle</code> watcher, start it, and in the
callback, free it. Also, use no error checking, as usual.</p>
<pre> static void
idle_cb (struct ev_loop *loop, struct ev_idle *w, int revents)
{
@ -1552,7 +1562,7 @@ believe me.</p>
</div>
<h1 id="OTHER_FUNCTIONS">OTHER FUNCTIONS</h1><p><a href="#TOP" class="toplink">Top</a></p>
<h1 id="OTHER_FUNCTIONS">OTHER FUNCTIONS</h1>
<div id="OTHER_FUNCTIONS_CONTENT">
<p>There are some other functions of possible interest. Described. Here. Now.</p>
<dl>
@ -1609,7 +1619,7 @@ loop!).</p>
</div>
<h1 id="LIBEVENT_EMULATION">LIBEVENT EMULATION</h1><p><a href="#TOP" class="toplink">Top</a></p>
<h1 id="LIBEVENT_EMULATION">LIBEVENT EMULATION</h1>
<div id="LIBEVENT_EMULATION_CONTENT">
<p>Libev offers a compatibility emulation layer for libevent. It cannot
emulate the internals of libevent, so here are some usage hints:</p>
@ -1629,7 +1639,7 @@ to use the libev header file and library.</dt>
</dl>
</div>
<h1 id="C_SUPPORT">C++ SUPPORT</h1><p><a href="#TOP" class="toplink">Top</a></p>
<h1 id="C_SUPPORT">C++ SUPPORT</h1>
<div id="C_SUPPORT_CONTENT">
<p>Libev comes with some simplistic wrapper classes for C++ that mainly allow
you to use some convinience methods to start/stop watchers and also change
@ -1734,7 +1744,7 @@ the constructor.</p>
</pre>
</div>
<h1 id="MACRO_MAGIC">MACRO MAGIC</h1><p><a href="#TOP" class="toplink">Top</a></p>
<h1 id="MACRO_MAGIC">MACRO MAGIC</h1>
<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
@ -1795,7 +1805,7 @@ wether multiple loops are supported or not.</p>
</pre>
</div>
<h1 id="EMBEDDING">EMBEDDING</h1><p><a href="#TOP" class="toplink">Top</a></p>
<h1 id="EMBEDDING">EMBEDDING</h1>
<div id="EMBEDDING_CONTENT">
<p>Libev can (and often is) directly embedded into host
applications. Examples of applications that embed it include the Deliantra
@ -2099,7 +2109,7 @@ that everybody includes and which overrides some autoconf choices:</p>
</pre>
</div>
<h1 id="COMPLEXITIES">COMPLEXITIES</h1><p><a href="#TOP" class="toplink">Top</a></p>
<h1 id="COMPLEXITIES">COMPLEXITIES</h1>
<div id="COMPLEXITIES_CONTENT">
<p>In this section the complexities of (many of) the algorithms used inside
libev will be explained. For complexity discussions about backends see the
@ -2122,7 +2132,7 @@ documentation for <code>ev_default_init</code>.</p>
</div>
<h1 id="AUTHOR">AUTHOR</h1><p><a href="#TOP" class="toplink">Top</a></p>
<h1 id="AUTHOR">AUTHOR</h1>
<div id="AUTHOR_CONTENT">
<p>Marc Lehmann &lt;libev@schmorp.de&gt;.</p>

87
ev.pod

@ -4,10 +4,12 @@ libev - a high performance full-featured event loop written in C
=head1 SYNOPSIS
/* this is the only header you need */
#include <ev.h>
/* what follows is a fully working example program */
=head1 EXAMPLE PROGRAM
#include <ev.h>
ev_io stdin_watcher;
ev_timer timeout_watcher;
@ -63,23 +65,28 @@ watcher.
=head1 FEATURES
Libev supports select, poll, the linux-specific epoll and the bsd-specific
kqueue mechanisms for file descriptor events, relative timers, absolute
timers with customised rescheduling, signal events, process status change
events (related to SIGCHLD), and event watchers dealing with the event
loop mechanism itself (idle, prepare and check watchers). It also is quite
fast (see this L<benchmark|http://libev.schmorp.de/bench.html> comparing
it to libevent for example).
Libev supports C<select>, C<poll>, the linux-specific C<epoll>, the
bsd-specific C<kqueue> and the solaris-specific event port mechanisms
for file descriptor events (C<ev_io>), relative timers (C<ev_timer>),
absolute timers with customised rescheduling (C<ev_periodic>), synchronous
signals (C<ev_signal>), process status change events (C<ev_child>), and
event watchers dealing with the event loop mechanism itself (C<ev_idle>,
C<ev_embed>, C<ev_prepare> and C<ev_check> watchers) as well as
file watchers (C<ev_stat>) and even limited support for fork events
(C<ev_fork>).
It also is quite fast (see this
L<benchmark|http://libev.schmorp.de/bench.html> comparing it to libevent
for example).
=head1 CONVENTIONS
Libev is very configurable. In this manual the default configuration
will be described, which supports multiple event loops. For more info
about various configuration options please have a look at the file
F<README.embed> in the libev distribution. If libev was configured without
support for multiple event loops, then all functions taking an initial
argument of name C<loop> (which is always of type C<struct ev_loop *>)
will not have this argument.
Libev is very configurable. In this manual the default configuration will
be described, which supports multiple event loops. For more info about
various configuration options please have a look at B<EMBED> section in
this manual. If libev was configured without support for multiple event
loops, then all functions taking an initial argument of name C<loop>
(which is always of type C<struct ev_loop *>) will not have this argument.
=head1 TIME REPRESENTATION
@ -118,8 +125,8 @@ as this indicates an incompatible change. Minor versions are usually
compatible to older versions, so a larger minor version alone is usually
not a problem.
Example: make sure we haven't accidentally been linked against the wrong
version:
Example: Make sure we haven't accidentally been linked against the wrong
version.
assert (("libev version mismatch",
ev_version_major () == EV_VERSION_MAJOR
@ -169,8 +176,8 @@ You could override this function in high-availability programs to, say,
free some memory if it cannot allocate memory, to use a special allocator,
or even to sleep a while and retry until some memory is available.
Example: replace the libev allocator with one that waits a bit and then
retries: better than mine).
Example: Replace the libev allocator with one that waits a bit and then
retries).
static void *
persistent_realloc (void *ptr, size_t size)
@ -199,7 +206,7 @@ matter what, when it returns. That is, libev will generally retry the
requested operation, or, if the condition doesn't go away, do bad stuff
(such as abort).
Example: do the same thing as libev does internally:
Example: This is basically the same thing that libev does internally, too.
static void
fatal_error (const char *msg)
@ -355,7 +362,7 @@ always distinct from the default loop. Unlike the default loop, it cannot
handle signal and child watchers, and attempts to do so will be greeted by
undefined behaviour (or a failed assertion if assertions are enabled).
Example: try to create a event loop that uses epoll and nothing else.
Example: Try to create a event loop that uses epoll and nothing else.
struct ev_loop *epoller = ev_loop_new (EVBACKEND_EPOLL | EVFLAG_NOENV);
if (!epoller)
@ -464,7 +471,7 @@ Here are the gory details of what C<ev_loop> does:
- If ev_unloop has been called or EVLOOP_ONESHOT or EVLOOP_NONBLOCK
were used, return, otherwise continue with step *.
Example: queue some jobs and then loop until no events are outsanding
Example: Queue some jobs and then loop until no events are outsanding
anymore.
... queue jobs here, make sure they register event watchers as long
@ -494,18 +501,18 @@ no event watchers registered by it are active. It is also an excellent
way to do this for generic recurring timers or from within third-party
libraries. Just remember to I<unref after start> and I<ref before stop>.
Example: create a signal watcher, but keep it from keeping C<ev_loop>
Example: Create a signal watcher, but keep it from keeping C<ev_loop>
running when nothing else is active.
struct dv_signal exitsig;
struct ev_signal exitsig;
ev_signal_init (&exitsig, sig_cb, SIGINT);
ev_signal_start (myloop, &exitsig);
evf_unref (myloop);
ev_signal_start (loop, &exitsig);
evf_unref (loop);
Example: for some weird reason, unregister the above signal handler again.
Example: For some weird reason, unregister the above signal handler again.
ev_ref (myloop);
ev_signal_stop (myloop, &exitsig);
ev_ref (loop);
ev_signal_stop (loop, &exitsig);
=back
@ -816,9 +823,9 @@ The events being watched.
=back
Example: call C<stdin_readable_cb> when STDIN_FILENO has become, well
Example: Call C<stdin_readable_cb> when STDIN_FILENO has become, well
readable, but only once. Since it is likely line-buffered, you could
attempt to read a whole line in the callback:
attempt to read a whole line in the callback.
static void
stdin_readable_cb (struct ev_loop *loop, struct ev_io *w, int revents)
@ -918,7 +925,7 @@ which is also when any modifications are taken into account.
=back
Example: create a timer that fires after 60 seconds.
Example: Create a timer that fires after 60 seconds.
static void
one_minute_cb (struct ev_loop *loop, struct ev_timer *w, int revents)
@ -930,7 +937,7 @@ Example: create a timer that fires after 60 seconds.
ev_timer_init (&mytimer, one_minute_cb, 60., 0.);
ev_timer_start (loop, &mytimer);
Example: create a timeout timer that times out after 10 seconds of
Example: Create a timeout timer that times out after 10 seconds of
inactivity.
static void
@ -1065,7 +1072,7 @@ the periodic timer fires or C<ev_periodic_again> is being called.
=back
Example: call a callback every hour, or, more precisely, whenever the
Example: Call a callback every hour, or, more precisely, whenever the
system clock is divisible by 3600. The callback invocation times have
potentially a lot of jittering, but good long-term stability.
@ -1079,7 +1086,7 @@ potentially a lot of jittering, but good long-term stability.
ev_periodic_init (&hourly_tick, clock_cb, 0., 3600., 0);
ev_periodic_start (loop, &hourly_tick);
Example: the same as above, but use a reschedule callback to do it:
Example: The same as above, but use a reschedule callback to do it:
#include <math.h>
@ -1091,7 +1098,7 @@ Example: the same as above, but use a reschedule callback to do it:
ev_periodic_init (&hourly_tick, clock_cb, 0., 0., my_scheduler_cb);
Example: call a callback every hour, starting now:
Example: Call a callback every hour, starting now:
struct ev_periodic hourly_tick;
ev_periodic_init (&hourly_tick, clock_cb,
@ -1162,7 +1169,7 @@ C<waitpid> and C<sys/wait.h> documentation for details).
=back
Example: try to exit cleanly on SIGINT and SIGTERM.
Example: Try to exit cleanly on SIGINT and SIGTERM.
static void
sigint_cb (struct ev_loop *loop, struct ev_signal *w, int revents)
@ -1301,8 +1308,8 @@ believe me.
=back
Example: dynamically allocate an C<ev_idle>, start it, and in the
callback, free it. Alos, use no error checking, as usual.
Example: Dynamically allocate an C<ev_idle> watcher, start it, and in the
callback, free it. Also, use no error checking, as usual.
static void
idle_cb (struct ev_loop *loop, struct ev_idle *w, int revents)

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