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- <meta name="created" content="Fri Dec 7 20:07:44 2007" />
+ <meta name="created" content="Fri Dec 7 20:23:46 2007" />
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<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>All of the following are about amortised time: If an array needs to be
+extended, libev needs to realloc and move the whole array, but this
+happens asymptotically never with higher number of elements, so O(1) might
+mean it might do a lengthy realloc operation in rare cases, but on average
+it is much faster and asymptotically approaches constant time.</p>
<p>
<dl>
<dt>Starting and stopping timer/periodic watchers: O(log skipped_other_timers)</dt>
</dd>
<dt>Starting io/check/prepare/idle/signal/child watchers: O(1)</dt>
<dd>
- <p>These just add the watcher into an array or at the head of a list. If
-the array needs to be extended libev needs to realloc and move the whole
-array, but this happen asymptotically less and less with more watchers,
-thus amortised O(1).</p>
+ <p>These just add the watcher into an array or at the head of a list.
+=item Stopping check/prepare/idle watchers: O(1)</p>
</dd>
- <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 % EV_PID_HASHSIZE))</dt>
<dd>
<p>These watchers are stored in lists then need to be walked to find the
projects / software / libev.git / blobdiff