Waitset Use Cases

Using wait-sets and conditions. More...

Using wait-sets and conditions.

Setting up a wait-set

• Create a wait-set

  WaitSet waitset = new WaitSet();

• Attach conditions

  Condition cond1 = ...;
  Condition cond2 = entity.get_statuscondition();
  Condition cond3 = reader.create_readcondition(
      SampleStateKind.NOT_READ_SAMPLE_STATE,
      ViewStateKind.ANY_VIEW_STATE,
      InstanceStateKind.ANY_INSTANCE_STATE);
  Condition cond4 = new GuardCondition();
  Condition cond5 = ...;                                             
  
  waitset.attach_condition(cond1);
  waitset.attach_condition(cond2);
  waitset.attach_condition(cond3);
  waitset.attach_condition(cond4);
  waitset.attach_condition(cond5);

Waiting for condition(s) to trigger

• Set up a wait-set

• Wait for a condition to trigger or timeout, whichever occurs first

  Duration_t timeout = new Duration_t(0, 1000000); // 1ms
  
  ConditionSeq active_conditions = new ConditionSeq(); // list of active conditions
  
  boolean is_cond1_triggered = false;
  boolean is_cond2_triggered = false;
  
  try {
      waitset.wait(active_conditions, timeout);
  
      // check if "cond1" or "cond2" are triggered:
      for (int i = 0; i < active_conditions.size(); ++i) {
          if (active_conditions.get(i) == cond1) {
              System.out.println("Cond1 was triggered!");
              is_cond1_triggered = true;
          }
          if (active_conditions.get(i) == cond2) {
              System.out.println("Cond2 was triggered!");
              is_cond2_triggered = true;
          }
      }
  
      if (is_cond1_triggered) {
          // ... do something because "cond1" was triggered ...
      }
  
      if (is_cond2_triggered) {
          // ... do something because "cond2" was triggered ...
      }
  } catch (RETCODE_TIMEOUT timed_out) {
      // timeout!
      System.out.println(
          "Wait timed out!! None of the conditions was triggered.");
  } catch (RETCODE_ERROR ex) {
      // ... check for cause of failure
       throw ex;
  }

Tearing down a wait-set

• Delete the wait-set

  waitset.delete();       
  waitset = null;
  // let the wait set be garbage collected