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Diffstat (limited to 'ev.html')
| -rw-r--r-- | ev.html | 31 |
1 files changed, 25 insertions, 6 deletions
@@ -6,7 +6,7 @@ <meta name="description" content="Pod documentation for libev" /> <meta name="inputfile" content="<standard input>" /> <meta name="outputfile" content="<standard output>" /> - <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" 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> |