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--- getting_started:tutorials:tasking1 [2020/11/26 15:53] – created ursgraf
+++ getting_started:tutorials:tasking1 [2021/03/31 17:27] (current) – [Main Task with Several Harmonic Tasks] ursgraf
@@ Line 1: / Line 1: @@
 ====== Harmonic Tasks ======
-The [[eeros_architecture:control_system:executor|]] runs the time domains of the control system and the safety system. The time domains are handled by harmonic tasks.
+The [[eeros_architecture:control_system:executor|]] runs the time domains of the control system and the safety system. The time domains are handled by harmonic tasks. The following examples demonstrate the use of such harmonic tasks.
+===== Main task with one Harmonic =====
+In the EEROS library you will find a directory with examples. For this example see [[https://github.com/eeros-project/eeros-framework/blob/master/examples/task/PeriodicExample1.cpp|PeriodicExample1.cpp]].
+Open a shell in the build directory of your EEROS library and run
+<code>
+$ sudo ./examples/task/periodicExample1
+</code>
-In the EEROS library you will find a directory with examples. Open a shell in the build directory of your EEROS library and run ''examples/controlsystem/PeriodicExample1''.
 This examples does:
-  * Creates a main task //ss// with an execution period of five milliseconds. The task itself is defined of type ''Lambda'' with a run method given by an empty lambda function.
+  * Creates a main task //mainTask// with an execution period of 10ms. The task itself is defined of type ''Lambda'' with a run method given by an empty lambda function.
-  * Creates a time domain //t1// with a period of five milliseconds.
+  * Creates a time domain //harmonicTask// with a period of 2s.
-Both harmonic tasks have a periodic counter which measure its periods and run times. Once every 1000th run the results are logged. The results are printed in units of seconds.
+Both harmonic tasks have a periodic counter which measure its periods and run times. Once every 200th run the results of the main task are logged. The harmonic task logs every time it runs. The results are printed in units of seconds.
 Additionally both harmonics have a default monitor function added. This monitor function logs a warning if the measured period differs more than 5%. Depending on your hardware platform and realtime support of your operating system you might get no warnings, several or many warnings.
+===== Harmonic with no Main Task =====
+If you don't specify a main task, the executor will create a default main task, which does nothing, see [[https://github.com/eeros-project/eeros-framework/blob/master/examples/task/PeriodicExample2.cpp|PeriodicExample2.cpp]].
+Run
+<code>
+$ sudo ./examples/task/periodicExample2
+</code>
+This examples does:
+  * Creates a time domain //harmonicTask// with a period of 2s.
+The tasks has a periodic counter which measure its periods and run times. The harmonic task logs every time it runs. The results are printed in units of seconds.
+===== Main Task with Several Harmonic Tasks =====
+An example with many tasks can be found under [[https://github.com/eeros-project/eeros-framework/blob/master/examples/task/PeriodicExample3.cpp|PeriodicExample3.cpp]].
+Run
+<code>
+$ sudo ./examples/task/periodicExample3
+</code>
+This examples does:
+  * Creates a main task //mainTask// with an execution period of one second. The task itself is defined of type ''Lambda'' with a run method given by a lambda function. It prints out two messages with a short delay in between.
+  * Creates a periodic //t1// with a period of one second. Its run method prints out some messages with a short delay in between. //t1// runs concurrently to //mainTask//.
+  * Creates a periodic //t2// with a period of two seconds. Its run method prints out some messages with a short delay in between. //t2// runs after //t1// has finished.
+  * Creates a periodic //t4// with a period of four seconds. Its run method prints out some messages with a short delay in between. //t4// runs after //t2// has finished.
+  * Creates a periodic //t3// with a period of five seconds. Its run method prints out some messages with a short delay in between. //t3// runs after //t1// has finished but concurrently to //t2//.
+  * Creates a periodic //t5// with a period of three seconds. Its run method prints out some messages with a short delay in between. //t5// runs concurrently to //t1//.
+All of the harmonic tasks have a periodic counter which measure its periods and run times. Once every 10th run the results are logged. The results are printed in milliseconds.