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eeros_architecture:sequencer:define_sequence

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eeros_architecture:sequencer:define_sequence [2019/03/21 07:54] – [Write your own Class] grafeeros_architecture:sequencer:define_sequence [2023/02/26 00:25] (current) – [Add Parameters] ursgraf
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 </code> </code>
  
-If you define a main sequence which has no calling sequence and which must be nonblocking per default, you can make use of a simpler constructor by calling+If you define a main sequence which has no calling sequence and which must be nonblocking per default, you can make use of another constructor by calling
 <code cpp> <code cpp>
 class MainSequence : public Sequence { class MainSequence : public Sequence {
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     step2();     step2();
     step3();     step3();
 +    return 0;
   }   }
 </code> </code>
-Its mandatory to implement this function. If not, no work is done and the step or sequence terminates immediately. \\+Its mandatory to implement this function. If not, no work is done and the step or sequence terminates immediately.  
 +A step or blocking sequence can return a value of type ''int''. This can be useful to hand back basic information to the calling sequence.  \\ 
 There might be sequences which should never stop. This must be done as shown below: There might be sequences which should never stop. This must be done as shown below:
 <code cpp> <code cpp>
 public: public:
   int action() {   int action() {
-    while (Sequencer::running) step1();+    while (state == SequenceState::running) step1();
     // while (true) step1();  // WRONG!     // while (true) step1();  // WRONG!
 +    return 0;
   }   }
 </code> </code>
-This guarantees that the sequence could be stopped by the main program due to some external event such as a signal.+This guarantees that the sequence could be aborted, resumed or restarted due to exception sequences.
 ===== Define Preconditions ===== ===== Define Preconditions =====
 You may want to start a sequence or step only if a certain precondition is met. Override the function //checkPreCondition()//, e.g.: You may want to start a sequence or step only if a certain precondition is met. Override the function //checkPreCondition()//, e.g.:
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 <code cpp> <code cpp>
   int operator() (double x, double y) {   int operator() (double x, double y) {
-    this.x = x; // store the first parameter into a local variable for further use +    this->x = x; // store the first parameter into a local variable for further use 
-    this.y = y; // store the second parameter into a local variable for further use +    this->y = y; // store the second parameter into a local variable for further use 
     return start();  // this will start the step or sequence     return start();  // this will start the step or sequence
   }   }
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 As mentioned before you should never wait by using //sleep// in a action method. However, quite often it is desirable to wait for some time to pass when running sequences. How to do properly? Use the predefined step ''Wait''. Study the examples in [[getting_started:tutorials:start|]]. Contrary to a simple //sleep// it does not block the sequencer and the checking of monitors of this step or sequence continues unhindered. As mentioned before you should never wait by using //sleep// in a action method. However, quite often it is desirable to wait for some time to pass when running sequences. How to do properly? Use the predefined step ''Wait''. Study the examples in [[getting_started:tutorials:start|]]. Contrary to a simple //sleep// it does not block the sequencer and the checking of monitors of this step or sequence continues unhindered.
  
-===== Returning Values ===== +
-A step or blocking sequence can return a value of type ''int''. This can be useful to hand back basic information to the calling sequence.+
eeros_architecture/sequencer/define_sequence.1553151246.txt.gz · Last modified: 2019/03/21 07:54 by graf