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--- for_developers:timing_measurement [2016/08/15 16:43] – [Accuracy of the measurement] gehrig
+++ for_developers:timing_measurement [2016/09/13 14:03] – [How the timer works] gehrig
@@ Line 2: / Line 2: @@
 ===== How the timer works =====
-The timer function is included in the Executer object. It measures the time each start of a cycle (//counter.tick()//). Additionally it measures the run time of all threads with //counter.tock()//. The timer keeps track of previous measurements and calculates after each //counter.tock// minimal value, maximal value, mean value and the variance of the period time and run time as well.
+The timer function is included in the Executer object. It registers the system time each time the executor executes its list of tasks (//counter.tick()//). When all tasks are done the system time is registered again (//counter.tock()//). The timer keeps track of the previous measurement and calculates the run time in between consecutive runs as well as period and jitter.
+  * run time: counter.tock() - counter.tick()
+  * period: counter.tick()[t=n] - counter.tick()[t=n-1]
+  * jitter: |actual period - set period|
+Of these three measurements the minimal value, maximal value, mean value and the variance are calculated.
+Implementation in //Execurot.cpp//:
+<code cpp>
+...
+loop {
+    counter.tick();
+    //code under test (list.run();)
+    counter.tock();
+}
+...
+</code>
 ===== Influence of the measurement on the real time performance of the system =====