java.lang.Object
org.apache.derby.impl.store.raw.xact.NoLocking
org.apache.derby.impl.store.raw.xact.RowLocking3
org.apache.derby.impl.store.raw.xact.RowLockingRR
org.apache.derby.impl.store.raw.xact.RowLocking2
- All Implemented Interfaces:
- org.apache.derby.iapi.store.raw.LockingPolicy
- Direct Known Subclasses:
- RowLocking1, RowLocking2nohold
- public class RowLocking2
- extends RowLockingRR
A locking policy that implements row level locking with isolation degree 2.
The approach is to place all "write" container and row locks on the
transaction group lock list. Locks on this group will last until end
of transaction. All "read" container and row locks will be placed
on a group list, key'd by the ContainerId of the lock. Locks on this
list will either be released explicitly by the caller, or will be released
as a group when the unlockContainer() call is made.
Note that write operations extend from the RowLocking3 implementations.
| Fields inherited from class org.apache.derby.impl.store.raw.xact.RowLocking3 |
lf |
|
Method Summary |
boolean |
lockContainer(org.apache.derby.iapi.store.raw.Transaction t,
org.apache.derby.iapi.store.raw.ContainerHandle container,
boolean waitForLock,
boolean forUpdate)
Obtain container level intent lock. |
void |
lockRecordForRead(org.apache.derby.iapi.services.locks.Latch latch,
org.apache.derby.iapi.store.raw.RecordHandle record,
boolean forUpdate)
Obtain lock on record being read while holding a latch. |
boolean |
lockRecordForRead(org.apache.derby.iapi.store.raw.Transaction t,
org.apache.derby.iapi.store.raw.ContainerHandle container_handle,
org.apache.derby.iapi.store.raw.RecordHandle record,
boolean waitForLock,
boolean forUpdate)
Obtain lock on record being read. |
void |
unlockContainer(org.apache.derby.iapi.store.raw.Transaction t,
org.apache.derby.iapi.store.raw.ContainerHandle container_handle)
Unlock read locks. |
void |
unlockRecordAfterRead(org.apache.derby.iapi.store.raw.Transaction t,
org.apache.derby.iapi.store.raw.ContainerHandle container_handle,
org.apache.derby.iapi.store.raw.RecordHandle record,
boolean forUpdate,
boolean row_qualified)
Unlock a record after it has been locked for read. |
| Methods inherited from class java.lang.Object |
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait |
NO_LOCK
private static final org.apache.derby.iapi.store.raw.LockingPolicy NO_LOCK
RowLocking2
protected RowLocking2(org.apache.derby.iapi.services.locks.LockFactory lf)
lockContainer
public boolean lockContainer(org.apache.derby.iapi.store.raw.Transaction t,
org.apache.derby.iapi.store.raw.ContainerHandle container,
boolean waitForLock,
boolean forUpdate)
throws org.apache.derby.iapi.error.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.
Read locks are put in a separate "group" from the transaction, so that
when the container is closed it can release these read locks.
- Specified by:
lockContainer in interface org.apache.derby.iapi.store.raw.LockingPolicy- Overrides:
lockContainer in class RowLocking3
lockRecordForRead
public boolean lockRecordForRead(org.apache.derby.iapi.store.raw.Transaction t,
org.apache.derby.iapi.store.raw.ContainerHandle container_handle,
org.apache.derby.iapi.store.raw.RecordHandle record,
boolean waitForLock,
boolean forUpdate)
throws org.apache.derby.iapi.error.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 placed on separate group from transaction.
- Specified by:
lockRecordForRead in interface org.apache.derby.iapi.store.raw.LockingPolicy- Overrides:
lockRecordForRead in class RowLocking3
lockRecordForRead
public void lockRecordForRead(org.apache.derby.iapi.services.locks.Latch latch,
org.apache.derby.iapi.store.raw.RecordHandle record,
boolean forUpdate)
throws org.apache.derby.iapi.error.StandardException
- Obtain lock on record being read while holding a latch.
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 org.apache.derby.iapi.store.raw.LockingPolicy- Overrides:
lockRecordForRead in class RowLocking3
unlockRecordAfterRead
public void unlockRecordAfterRead(org.apache.derby.iapi.store.raw.Transaction t,
org.apache.derby.iapi.store.raw.ContainerHandle container_handle,
org.apache.derby.iapi.store.raw.RecordHandle record,
boolean forUpdate,
boolean row_qualified)
throws org.apache.derby.iapi.error.StandardException
- 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 org.apache.derby.iapi.store.raw.LockingPolicy- Overrides:
unlockRecordAfterRead in class RowLockingRR
unlockContainer
public void unlockContainer(org.apache.derby.iapi.store.raw.Transaction t,
org.apache.derby.iapi.store.raw.ContainerHandle container_handle)
- Unlock read locks.
In Cursor stability release all read locks obtained. unlockContainer()
will be called when the container is closed.
- Specified by:
unlockContainer in interface org.apache.derby.iapi.store.raw.LockingPolicy- Overrides:
unlockContainer in class NoLocking
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