Class RowLocking2nohold

All Implemented Interfaces:
LockingPolicy

public class RowLocking2nohold extends RowLocking2
A locking policy that implements row level locking with isolation degree 2, never holding read locks after they are granted. Exactly the same as RowLocking2, except that read locks are acquired using zeroDuration locks, which are immediately released by the lock manager after they are granted.
See Also:
  • Constructor Details

    • RowLocking2nohold

      protected RowLocking2nohold(LockFactory lf)
  • Method Details

    • lockRecordForRead

      public boolean lockRecordForRead(Transaction t, ContainerHandle container_handle, RecordHandle record, boolean waitForLock, boolean forUpdate) throws StandardException
      Obtain lock on record being read.

      Assumes that a table level IS has been acquired. Will acquire a Shared or Update lock on the row, depending on the "forUpdate" parameter.

      Read lock will be acquired using zeroDuration lock.

      Specified by:
      lockRecordForRead in interface LockingPolicy
      Overrides:
      lockRecordForRead in class RowLocking2
      Parameters:
      t - The transaction to associate the lock with.
      container_handle - Open Container used to get record. Will be used to row locks by the container they belong to.
      record - The record to be locked.
      waitForLock - Should lock request wait until granted?
      forUpdate - Whether to open for read or write access.
      Returns:
      true if the lock was granted, false if waitForLock was false and the lock could not be granted.
      Throws:
      StandardException - Standard exception policy.
      See Also:
    • unlockRecordAfterRead

      public void unlockRecordAfterRead(Transaction t, ContainerHandle container_handle, RecordHandle record, boolean forUpdate, boolean row_qualified)
      Description copied from class: RowLockingRR
      Unlock a record after it has been locked for read.

      In repeatable read only unlock records which "did not qualify". For example in a query like "select * from foo where a = 1" on a table with no index it is only necessary to hold locks on rows where a=1, but in the process of finding those rows the system will get locks on other rows to verify they are committed before applying the qualifier. Those locks can be released under repeatable read isolation.

      Specified by:
      unlockRecordAfterRead in interface LockingPolicy
      Overrides:
      unlockRecordAfterRead in class RowLocking2
      See Also: