Field Detail

• NONE

  public static final long NONE

  Represents no value, or not set.

  See Also:

  Constant Field Values

• FIXED_SIZE

  public static final long FIXED_SIZE

Constructor Detail

• MultiVersionConcurrencyControl

  public MultiVersionConcurrencyControl()

• MultiVersionConcurrencyControl

  public MultiVersionConcurrencyControl(long startPoint)

  Construct and set read point. Write point is uninitialized.

Method Detail

• advanceTo

  public void advanceTo(long newStartPoint)

  Step the MVCC forward on to a new read/write basis.

  Parameters:

  newStartPoint -

• begin

  public MultiVersionConcurrencyControl.WriteEntry begin()

  Call begin(Runnable) with an empty Runnable.

• begin

  public MultiVersionConcurrencyControl.WriteEntry begin(Runnable action)

  Start a write transaction. Create a new MultiVersionConcurrencyControl.WriteEntry with a new write number and add it to our queue of ongoing writes. Return this WriteEntry instance. To complete the write transaction and wait for it to be visible, call completeAndWait(WriteEntry). If the write failed, call complete(WriteEntry) so we can clean up AFTER removing ALL trace of the failed write transaction.

  The action will be executed under the lock which means it can keep the same order with mvcc.

  See Also:

  complete(WriteEntry), completeAndWait(WriteEntry)

• await

  public void await()

  Wait until the read point catches up to the write point; i.e. wait on all outstanding mvccs to complete.

• completeAndWait

  public void completeAndWait(MultiVersionConcurrencyControl.WriteEntry e)

  Complete a MultiVersionConcurrencyControl.WriteEntry that was created by begin() then wait until the read point catches up to our write. At the end of this call, the global read point is at least as large as the write point of the passed in WriteEntry. Thus, the write is visible to MVCC readers.

• complete

  public boolean complete(MultiVersionConcurrencyControl.WriteEntry writeEntry)

  Mark the MultiVersionConcurrencyControl.WriteEntry as complete and advance the read point as much as possible. Call this even if the write has FAILED (AFTER backing out the write transaction changes completely) so we can clean up the outstanding transaction. How much is the read point advanced? Let S be the set of all write numbers that are completed. Set the read point to the highest numbered write of S.

  Parameters:

  writeEntry -

  Returns:

  true if e is visible to MVCC readers (that is, readpoint >= e.writeNumber)

• toString

  public String toString()

  Overrides:

  toString in class Object

• getReadPoint

  public long getReadPoint()

• getWritePoint

  public long getWritePoint()