Transient persestant memory-begin abort transaction-arraycopynonatomic

Question

If array defined as transient, then abort doesnt make any sense, chages are not rolled back.(Both for arrayCopy and arraycopyNonAtomic functions)
     public void AtomicNonatomic()
byte hello[] = {'H','E','L','L','O'};
          byte[] key_buffer = JCSystem.makeTransientByteArray((byte)16, JCSystem.CLEAR_ON_RESET);
          //byte[] key_buffer = new byte[16];
          JCSystem.beginTransaction();
          //Util.arrayCopy(hello, (short)0, key_buffer, (short)0, (short)5);
          Util.arrayCopyNonAtomic(hello,(short)0, key_buffer, (short)0, (short)5);
          for(byte i =0; i<2; i++)
          key_buffer=0; //This types of assigning values are atomic operations, so can be thougth as arrayCopy
          JCSystem.abortTransaction();          
If array not defined as transient and if arrayCopy is used then abort works
If array not defined as transient and if arrayCopyNonatomic is used then abort not works
     public void AtomicNonatomic()
          //byte[] key_buffer = JCSystem.makeTransientByteArray((byte)16, JCSystem.CLEAR_ON_RESET);
          byte[] key_buffer = new byte[16];
          JCSystem.beginTransaction();
          //Util.arrayCopy(hello, (short)0, key_buffer, (short)0, (short)5);
          Util.arrayCopyNonAtomic(hello,(short)0, key_buffer, (short)0, (short)5);
          for(byte i =0; i<2; i++)
          key_buffer[i]=0;
          JCSystem.abortTransaction();          
As a result begin-abort-commit should be used with non-transient arrays and without arrayCopyNonatomic function.
Edited by: simeranya_00 on Aug 7, 2010 6:51 AM
Edited by: simeranya_00 on Aug 7, 2010 6:56 AM

Answer 1

Check out JCRE specification. Therein you will find what is (not) part of a transaction.
1. All global arrays are not part of a transaction
2. All transient fields/arrays/keys are not part of a transaction
3. OwnerPIN object is not part of a transaction
4. All Java Card API methods are transactional, except arrayCopyNonAtomic and arrayFillNonAtomic
Lifetime of a transaction
begin <--> commit
begin <--> abort < -- rollback
begin <--> JCRE context (process method exit) < -- abort transaction (done by JCRE) < -- rollback
begin <--> uncaught exception < -- abort < -- rollback
begin <--> tear/reset < -- rollback