1. Rhapsody in C++ Tool Training "Essential" © I-Logix 1999-2000 v3.0 1/29/2001 Adv-1 Section 4 Advanced Mutexes

2. Rhapsody in C++ Tool Training "Essential" © I-Logix 1999-2000 v3.0 1/29/2001 Adv-2 Mutexes Rhapsody provides OMProtected which is a mutex (or binary semaphore) for protecting consecutive access to devices. OMProtected can be used as follows: –attribute OMProtected myMutex; –free myMutex.free(); –lock myMutex.lock();

3. Rhapsody in C++ Tool Training "Essential" © I-Logix 1999-2000 v3.0 1/29/2001 Adv-3 Animating Mutexes Rhapsody cannot display in animation, the value of attributes of type OMProtected. In order to use animation, the property AnimateAttributes for the attribute must be set to FALSE.

4. Rhapsody in C++ Tool Training "Essential" © I-Logix 1999-2000 v3.0 1/29/2001 Adv-4 Animating Attributes For animating attributes of a user defined type, the same problem can occur. To allow animation: –either set the property AnimateAttributes to FALSE –or add a global function operator<< for the user defined type –Or use the InstrumentationFunctionName ostream& operator<<(ostream& out, const tDate& d) { out << d.day << "/" << d.month << "/" << d.year; return out; };

5. Rhapsody in C++ Tool Training "Essential" © I-Logix 1999-2000 v3.0 1/29/2001 Adv-5 Instrumentation Function Name I To animate an attribute of type tTempUnits that is an enum of CELSIUS and FAHRENHEIT : Add a function showTempUnits as follows :

6. Rhapsody in C++ Tool Training "Essential" © I-Logix 1999-2000 v3.0 1/29/2001 Adv-6 Instrumentation Function Name II Set the Animate and AnimateArguments properties for this function to False :

7. Rhapsody in C++ Tool Training "Essential" © I-Logix 1999-2000 v3.0 1/29/2001 Adv-7 Instrumentation Function Name III For each attribute of type tTempUnits, set the InstrumentationFunctionName to showTempUnits

8. Rhapsody in C++ Tool Training "Essential" © I-Logix 1999-2000 v3.0 1/29/2001 Adv-8 Instrumentation Function Name IV To generate this operation only during animation, the following properties can be set for this function. New line

9. Rhapsody in C++ Tool Training "Essential" © I-Logix 1999-2000 v3.0 1/29/2001 Adv-9 Instrumentation Function Name V

10. Rhapsody in C++ Tool Training "Essential" © I-Logix 1999-2000 v3.0 1/29/2001 Adv-10 Unguarded Access to Adc::read() In the following example, each Sensor calls the Adc::read() operation to measure Voltage / Temperature or Pressure. The read operation selects the appropriate multiplexor input and does eight serial reads on DataIn.

11. Rhapsody in C++ Tool Training "Essential" © I-Logix 1999-2000 v3.0 1/29/2001 Adv-11 Unguarded Behavior Current read() operation is interrupted by another.

12. Rhapsody in C++ Tool Training "Essential" © I-Logix 1999-2000 v3.0 1/29/2001 Adv-12 Guarding Operations Rhapsody can use the mutex OMProtected to guard access to a particular operation to stop concurrent access. This can be done by setting the property concurrency from sequential to guarded. All operations in a same class, that are guarded will be guarded by the same mutex.

13. Rhapsody in C++ Tool Training "Essential" © I-Logix 1999-2000 v3.0 1/29/2001 Adv-13 Guarded Behavior Concurrent read() operation is blocked by mutex and is executed when current read() ends.

14. Rhapsody in C++ Tool Training "Essential" © I-Logix 1999-2000 v3.0 1/29/2001 Adv-14 Guarded Operation : Code

15. Rhapsody in C++ Tool Training "Essential" © I-Logix 1999-2000 v3.0 1/29/2001 Adv-15 Guarding Relations Rhapsody can also use the mutex OMProtected to guard access to a particular relation to stop concurrent access. This can be done by setting the property isGuarded from none to all ( mutator & accessor operations ) or just mutator.