Class RowLocking3

java.lang.Object
org.apache.derby.impl.store.raw.xact.NoLocking
org.apache.derby.impl.store.raw.xact.RowLocking3
All Implemented Interfaces:
LockingPolicy
Direct Known Subclasses:
RowLockingRR

public class RowLocking3 extends NoLocking
A locking policy that implements row level locking with isolation degree 3.
See Also:
  • Field Details

  • Constructor Details

  • Method Details

    • getReadLockType

      protected RowLock getReadLockType()
      Get type of lock to get while reading data.

      This routine is provided so that class's like RowLockingRR can override just this routine to get RS2 locks vs RS3 locks, and still reuse all the other code in this class.

      Returns:
      The lock type of a shared lock for this locking policy.
    • getUpdateLockType

      protected RowLock getUpdateLockType()
      Get type of lock to get while requesting "update" lock.

      This routine is provided so that class's like RowLockingRR can override just this routine to get RU2 locks vs RU3 locks, and still reuse all the other code in this class.

      Returns:
      The lock type of a shared lock for this locking policy.
    • getWriteLockType

      protected RowLock getWriteLockType()
      Get type of lock to get while writing data.

      This routine is provided so that class's like RowLockingRR can override just this routine to get RX2 locks vs RX3 locks, and still reuse all the other code in this class.

      Returns:
      The lock type of a shared lock for this locking policy.
    • lockContainer

      public boolean lockContainer(Transaction t, ContainerHandle container, boolean waitForLock, boolean forUpdate) throws StandardException
      Obtain container level intent lock.

      This implementation of row locking is 2 level, ie. table and row locking. It will interact correctly with tables opened with ContainerLocking3 locking mode.

      Updater's will get table level IX locks, and X row locks.

      Reader's will get table level IS locks, and S row locks.

      Specified by:
      lockContainer in interface LockingPolicy
      Overrides:
      lockContainer in class NoLocking
      Parameters:
      t - Transaction to associate lock with.
      container - Container to lock.
      waitForLock - Should lock request wait until granted?
      forUpdate - Should container be locked for update, or read?
      Returns:
      true if the lock was obtained, false if it wasn't. False should only be returned if the waitForLock policy was set to "false," and the lock was unavailable.
      Throws:
      StandardException - Standard exception policy.
      See Also:
    • 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.

      Specified by:
      lockRecordForRead in interface LockingPolicy
      Overrides:
      lockRecordForRead in class NoLocking
      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:
    • zeroDurationLockRecordForWrite

      public boolean zeroDurationLockRecordForWrite(Transaction t, RecordHandle record, boolean lockForInsertPreviousKey, boolean waitForLock) throws StandardException
      Obtain lock on record being written.

      Assumes that a table level IX has been acquired. Will acquire an Exclusive (X) lock on the row.

      Specified by:
      zeroDurationLockRecordForWrite in interface LockingPolicy
      Overrides:
      zeroDurationLockRecordForWrite in class NoLocking
      Parameters:
      t - transaction to associate the lock with.
      record - The record to be locked.
      lockForInsertPreviousKey - Lock is for a previous key of a insert.
      waitForLock - Should lock request wait until granted?
      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:
    • lockRecordForWrite

      public boolean lockRecordForWrite(Transaction t, RecordHandle record, boolean lockForInsert, boolean waitForLock) throws StandardException
      Obtain lock on record being written.

      Assumes that a table level IX has been acquired. Will acquire an Exclusive (X) lock on the row.

      Specified by:
      lockRecordForWrite in interface LockingPolicy
      Overrides:
      lockRecordForWrite in class NoLocking
      Parameters:
      t - The transaction to associate the lock with.
      record - The record to be locked.
      lockForInsert - Lock is for an insert.
      waitForLock - Should lock request wait until granted?
      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:
    • getMode

      public int getMode()
      Description copied from interface: LockingPolicy
      Get the mode of this policy
      Specified by:
      getMode in interface LockingPolicy
      Overrides:
      getMode in class NoLocking