Java compact1, compact2, compact3 java.util.concurrent.atomic Class AtomicStampedReference<V>（JDK8）

Constructor Detail

• AtomicStampedReference

  public AtomicStampedReference(V initialRef,
                                int initialStamp)

  Creates a new AtomicStampedReference with the given initial values.

  Parameters:

  initialRef - the initial reference

  initialStamp - the initial stamp

Method Detail

• getReference

  public V getReference()

  Returns the current value of the reference.

  Returns:

  the current value of the reference

• getStamp

  public int getStamp()

  Returns the current value of the stamp.

  Returns:

  the current value of the stamp

• get

  public V get(int[] stampHolder)

  Returns the current values of both the reference and the stamp. Typical usage is int[1] holder; ref = v.get(holder); .

  Parameters:

  stampHolder - an array of size of at least one. On return, stampholder[0] will hold the value of the stamp.

  Returns:

  the current value of the reference

• weakCompareAndSet

  public boolean weakCompareAndSet(V expectedReference,
                                   V newReference,
                                   int expectedStamp,
                                   int newStamp)

  Atomically sets the value of both the reference and stamp to the given update values if the current reference is == to the expected reference and the current stamp is equal to the expected stamp.

  May fail spuriously and does not provide ordering guarantees, so is only rarely an appropriate alternative to compareAndSet.

  Parameters:

  expectedReference - the expected value of the reference

  newReference - the new value for the reference

  expectedStamp - the expected value of the stamp

  newStamp - the new value for the stamp

  Returns:

  true if successful

• compareAndSet

  public boolean compareAndSet(V expectedReference,
                               V newReference,
                               int expectedStamp,
                               int newStamp)

  Atomically sets the value of both the reference and stamp to the given update values if the current reference is == to the expected reference and the current stamp is equal to the expected stamp.

  Parameters:

  expectedReference - the expected value of the reference

  newReference - the new value for the reference

  expectedStamp - the expected value of the stamp

  newStamp - the new value for the stamp

  Returns:

  true if successful

• set

  public void set(V newReference,
                  int newStamp)

  Unconditionally sets the value of both the reference and stamp.

  Parameters:

  newReference - the new value for the reference

  newStamp - the new value for the stamp

• attemptStamp

  public boolean attemptStamp(V expectedReference,
                              int newStamp)

  Atomically sets the value of the stamp to the given update value if the current reference is == to the expected reference. Any given invocation of this operation may fail (return false) spuriously, but repeated invocation when the current value holds the expected value and no other thread is also attempting to set the value will eventually succeed.

  Parameters:

  expectedReference - the expected value of the reference

  newStamp - the new value for the stamp

  Returns:

  true if successful