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authorroot <root>2007-11-28 11:27:29 +0000
committerroot <root>2007-11-28 11:27:29 +0000
commit71217f48ea498d7292ca3bf17b8bffe1ab97e642 (patch)
treed086a523b9d7b0922655db81e1e97694cf3d140b /ev.html
parent4ebe9e295b974622f802229ca8e371ee6df9525a (diff)
*** empty log message ***
Diffstat (limited to 'ev.html')
-rw-r--r--ev.html31
1 files changed, 25 insertions, 6 deletions
diff --git a/ev.html b/ev.html
index a107da8..ec6eb1b 100644
--- 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="Tue Nov 27 21:38:05 2007" />
+ <meta name="created" content="Wed Nov 28 12:27:27 2007" />
<meta name="generator" content="Pod::Xhtml 1.57" />
<link rel="stylesheet" href="http://res.tst.eu/pod.css"/></head>
<body>
@@ -1249,7 +1249,7 @@ not exist&quot; is signified by the <code>st_nlink</code> field being zero (whic
otherwise always forced to be at least one) and all the other fields of
the stat buffer having unspecified contents.</p>
<p>Since there is no standard to do this, the portable implementation simply
-calls <code>stat (2)</code> regulalry on the path to see if it changed somehow. You
+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
@@ -1259,8 +1259,13 @@ usually overkill.</p>
<p>This watcher type is not meant for massive numbers of stat watchers,
as even with OS-supported change notifications, this can be
resource-intensive.</p>
-<p>At the time of this writing, no specific OS backends are implemented, but
-if demand increases, at least a kqueue and inotify backend will be added.</p>
+<p>At the time of this writing, only the Linux inotify interface is
+implemented (implementing kqueue support is left as an exercise for the
+reader). Inotify will be used to give hints only and should not change the
+semantics of <code>ev_stat</code> watchers, which means that libev sometimes needs
+to fall back to regular polling again even with inotify, but changes are
+usually detected immediately, and if the file exists there will be no
+polling.</p>
<dl>
<dt>ev_stat_init (ev_stat *, callback, const char *path, ev_tstamp interval)</dt>
<dt>ev_stat_set (ev_stat *, const char *path, ev_tstamp interval)</dt>
@@ -2017,6 +2022,12 @@ backend for Solaris 10 systems.</p>
<dd>
<p>reserved for future expansion, works like the USE symbols above.</p>
</dd>
+ <dt>EV_USE_INOTIFY</dt>
+ <dd>
+ <p>If defined to be <code>1</code>, libev will compile in support for the Linux inotify
+interface to speed up <code>ev_stat</code> watchers. Its actual availability will
+be detected at runtime.</p>
+ </dd>
<dt>EV_H</dt>
<dd>
<p>The name of the <cite>ev.h</cite> header file used to include it. The default if
@@ -2081,7 +2092,15 @@ some inlining decisions, saves roughly 30% codesize of amd64.</p>
<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>
+increase this value (<i>must</i> be a power of two).</p>
+ </dd>
+ <dt>EV_INOTIFY_HASHSIZE</dt>
+ <dd>
+ <p><code>ev_staz</code> watchers use a small hash table to distribute workload by
+inotify watch id. 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 <code>ev_stat</code>
+watchers you might want to increase this value (<i>must</i> be a power of
+two).</p>
</dd>
<dt>EV_COMMON</dt>
<dd>
@@ -2148,7 +2167,7 @@ documentation for <code>ev_default_init</code>.</p>
<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>Stopping an io/signal/child watcher: O(number_of_watchers_for_this_(fd/signal/pid % EV_PID_HASHSIZE))</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>