add some small complexities section

14 years ago · 431e7d03bf
3 changed files with 86 additions and 2 deletions
--- a/ev.3
+++ b/ev.3
@ -1297,11 +1297,12 @@ pseudo-code only of course:
 \&  static ev_timer tw;
 .Ve
 .PP
-.Vb 8
+.Vb 9
 \&  static void
 \&  io_cb (ev_loop *loop, ev_io *w, int revents)
 \&  {
 \&    // set the relevant poll flags
+\&    // could also call adns_processreadable etc. here
 \&    struct pollfd *fd = (struct pollfd *)w->data;
 \&    if (revents & EV_READ ) fd->revents |= fd->events & POLLIN;
 \&    if (revents & EV_WRITE) fd->revents |= fd->events & POLLOUT;
@ -1902,6 +1903,32 @@ And a \fIev_cpp.C\fR implementation file that contains libev proper and is compi
 \&  #include "ev_cpp.h"
 \&  #include "ev.c"
 .Ve
+.SH "COMPLEXITIES"
+.IX Header "COMPLEXITIES"
+In this section the complexities of (many of) the algorithms used inside
+libev will be explained. For complexity discussions about backends see the
+documentation for \f(CW\*(C`ev_default_init\*(C'\fR.
+.RS 4
+.IP "Starting and stopping timer/periodic watchers: O(log skipped_other_timers)" 4
+.IX Item "Starting and stopping timer/periodic watchers: O(log skipped_other_timers)"
+.PD 0
+.IP "Changing timer/periodic watchers (by autorepeat, again): O(log skipped_other_timers)" 4
+.IX Item "Changing timer/periodic watchers (by autorepeat, again): O(log skipped_other_timers)"
+.IP "Starting io/check/prepare/idle/signal/child watchers: O(1)" 4
+.IX Item "Starting io/check/prepare/idle/signal/child watchers: O(1)"
+.IP "Stopping check/prepare/idle watchers: O(1)" 4
+.IX Item "Stopping check/prepare/idle watchers: O(1)"
+.IP "Stopping an io/signal/child watcher: O(number_of_watchers_for_this_(fd/signal/pid % 16))" 4
+.IX Item "Stopping an io/signal/child watcher: O(number_of_watchers_for_this_(fd/signal/pid % 16))"
+.IP "Finding the next timer per loop iteration: O(1)" 4
+.IX Item "Finding the next timer per loop iteration: O(1)"
+.IP "Each change on a file descriptor per loop iteration: O(number_of_watchers_for_this_fd)" 4
+.IX Item "Each change on a file descriptor per loop iteration: O(number_of_watchers_for_this_fd)"
+.IP "Activating one watcher: O(1)" 4
+.IX Item "Activating one watcher: O(1)"
+.RE
+.RS 4
+.PD
 .SH "AUTHOR"
 .IX Header "AUTHOR"
 Marc Lehmann <libev@schmorp.de>.
--- a/ev.html
+++ b/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="Mon Nov 26 10:52:13 2007" />
+	<meta name="created" content="Mon Nov 26 11:20:35 2007" />
 	<meta name="generator" content="Pod::Xhtml 1.57" />
 <link rel="stylesheet" href="http://res.tst.eu/pod.css"/></head>
 <body>
@ -52,6 +52,7 @@
 <li><a href="#EXAMPLES">EXAMPLES</a></li>
 </ul>
 </li>
+<li><a href="#COMPLEXITIES">COMPLEXITIES</a></li>
 <li><a href="#AUTHOR">AUTHOR</a>
 </li>
 </ul><hr />
@ -1178,6 +1179,7 @@ pseudo-code only of course:</p>
  io_cb (ev_loop *loop, ev_io *w, int revents)
  {
    // set the relevant poll flags
+    // could also call adns_processreadable etc. here
    struct pollfd *fd = (struct pollfd *)w-&gt;data;
    if (revents &amp; EV_READ ) fd-&gt;revents |= fd-&gt;events &amp; POLLIN;
    if (revents &amp; EV_WRITE) fd-&gt;revents |= fd-&gt;events &amp; POLLOUT;
@ -1755,8 +1757,34 @@ that everybody includes and which overrides some autoconf choices:</p>
 <pre>  #include &quot;ev_cpp.h&quot;
  #include &quot;ev.c&quot;

+
+
+
 </pre>

+</div>
+<h1 id="COMPLEXITIES">COMPLEXITIES</h1><p><a href="#TOP" class="toplink">Top</a></p>
+<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
+documentation for <code>ev_default_init</code>.</p>
+		<p>
+			<dl>
+				<dt>Starting and stopping timer/periodic watchers: O(log skipped_other_timers)</dt>
+				<dt>Changing timer/periodic watchers (by autorepeat, again): O(log skipped_other_timers)</dt>
+				<dt>Starting io/check/prepare/idle/signal/child watchers: O(1)</dt>
+				<dt>Stopping check/prepare/idle watchers: O(1)</dt>
+				<dt>Stopping an io/signal/child watcher: O(number_of_watchers_for_this_(fd/signal/pid % 16))</dt>
+				<dt>Finding the next timer per loop iteration: O(1)</dt>
+				<dt>Each change on a file descriptor per loop iteration: O(number_of_watchers_for_this_fd)</dt>
+				<dt>Activating one watcher: O(1)</dt>
+			</dl>
+		</p>
+
+
+
+
+
 </div>
 <h1 id="AUTHOR">AUTHOR</h1><p><a href="#TOP" class="toplink">Top</a></p>
 <div id="AUTHOR_CONTENT">
--- a/ev.pod
+++ b/ev.pod
@ -1162,6 +1162,7 @@ pseudo-code only of course:
  io_cb (ev_loop *loop, ev_io *w, int revents)
  {
    // set the relevant poll flags
+    // could also call adns_processreadable etc. here
    struct pollfd *fd = (struct pollfd *)w->data;
    if (revents & EV_READ ) fd->revents |= fd->events & POLLIN;
    if (revents & EV_WRITE) fd->revents |= fd->events & POLLOUT;
@ -1757,6 +1758,34 @@ And a F<ev_cpp.C> implementation file that contains libev proper and is compiled
  #include "ev_cpp.h"
  #include "ev.c"

+
+=head1 COMPLEXITIES
+
+In this section the complexities of (many of) the algorithms used inside
+libev will be explained. For complexity discussions about backends see the
+documentation for C<ev_default_init>.
+
+=over 4
+
+=item Starting and stopping timer/periodic watchers: O(log skipped_other_timers)
+
+=item Changing timer/periodic watchers (by autorepeat, again): O(log skipped_other_timers)
+
+=item Starting io/check/prepare/idle/signal/child watchers: O(1)
+
+=item Stopping check/prepare/idle watchers: O(1)
+
+=item Stopping an io/signal/child watcher: O(number_of_watchers_for_this_(fd/signal/pid % 16))
+
+=item Finding the next timer per loop iteration: O(1)
+
+=item Each change on a file descriptor per loop iteration: O(number_of_watchers_for_this_fd)
+
+=item Activating one watcher: O(1)
+
+=back
+
+
 =head1 AUTHOR

 Marc Lehmann <libev@schmorp.de>.