| 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
org.apache.derby.impl.store.raw.xact.RowLocking1
| RowLocking1 | | public class RowLocking1 extends RowLocking2 (Code) | | A locking policy that implements row level locking with isolation degree 1.
This is an implementation of Gray's degree 1 isolation, read uncommitted,
or often referred to as dirty reads. Basically read operations are
done with no locking.
This locking policy is only to be used for read operations.
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.
This implementation will still get table level intent locks. This is to
prevent hard cases where the container otherwise could be deleted while
read uncommitted reader is still accessing it. In order to not get table
level intent locks some sort of other ddl level lock would have to be
implemented.
All "read" row locks will be not be requested.
Note that write operations extend from the RowLocking3 implementations.
See Also: org.apache.derby.iapi.store.raw.LockingPolicy |
| Method Summary | |
| public boolean | lockRecordForRead(Transaction t, ContainerHandle container_handle, RecordHandle record, boolean waitForLock, boolean forUpdate)
Obtain lock on record being read.
Assumes that a table level IS has been acquired. | | public void | lockRecordForRead(Latch latch, RecordHandle record, boolean forUpdate)
Obtain lock on record being read while holding a latch.
Assumes that a table level IS has been acquired. | | public void | unlockRecordAfterRead(Transaction t, ContainerHandle container_handle, RecordHandle record, boolean forUpdate, boolean row_qualified)
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| lockRecordForRead | | public boolean lockRecordForRead(Transaction t, ContainerHandle container_handle, RecordHandle record, boolean waitForLock, boolean forUpdate) throws StandardException(Code) | | 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.
Parameters:
t - The transaction to associate the lock with.
Parameters:
record - The record to be locked.
Parameters:
waitForLock - Should lock request wait until granted?
Parameters:
forUpdate - Whether to open for read or write access. true if the lock was granted, false if waitForLock was false and the lock could not be granted.
exception:
StandardException - Standard exception policy. |
| lockRecordForRead | | public void lockRecordForRead(Latch latch, RecordHandle record, boolean forUpdate) throws StandardException(Code) | | 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.
Parameters:
latch - The latch being held.
Parameters:
record - The record to be locked.
Parameters:
forUpdate - Whether to open for read or write access.
exception:
StandardException - Standard exception policy. |
| Methods inherited from org.apache.derby.impl.store.raw.xact.RowLocking2 | public boolean lockContainer(Transaction t, ContainerHandle container, boolean waitForLock, boolean forUpdate) throws StandardException(Code)(Java Doc)
public boolean lockRecordForRead(Transaction t, ContainerHandle container_handle, RecordHandle record, boolean waitForLock, boolean forUpdate) throws StandardException(Code)(Java Doc)
public void lockRecordForRead(Latch latch, RecordHandle record, boolean forUpdate) throws StandardException(Code)(Java Doc)
public void unlockContainer(Transaction t, ContainerHandle container_handle)(Code)(Java Doc)
public void unlockRecordAfterRead(Transaction t, ContainerHandle container_handle, RecordHandle record, boolean forUpdate, boolean row_qualified) throws StandardException(Code)(Java Doc)
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| Methods inherited from org.apache.derby.impl.store.raw.xact.RowLocking3 | public int getMode()(Code)(Java Doc)
protected RowLock getReadLockType()(Code)(Java Doc)
protected RowLock getUpdateLockType()(Code)(Java Doc)
protected RowLock getWriteLockType()(Code)(Java Doc)
public boolean lockContainer(Transaction t, ContainerHandle container, boolean waitForLock, boolean forUpdate) throws StandardException(Code)(Java Doc)
public boolean lockRecordForRead(Transaction t, ContainerHandle container_handle, RecordHandle record, boolean waitForLock, boolean forUpdate) throws StandardException(Code)(Java Doc)
public void lockRecordForRead(Latch latch, RecordHandle record, boolean forUpdate) throws StandardException(Code)(Java Doc)
public boolean lockRecordForWrite(Transaction t, RecordHandle record, boolean lockForInsert, boolean waitForLock) throws StandardException(Code)(Java Doc)
public void lockRecordForWrite(Latch latch, RecordHandle record) throws StandardException(Code)(Java Doc)
public boolean zeroDurationLockRecordForWrite(Transaction t, RecordHandle record, boolean lockForInsertPreviousKey, boolean waitForLock) throws StandardException(Code)(Java Doc)
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| Methods inherited from org.apache.derby.impl.store.raw.xact.NoLocking | public int getMode()(Code)(Java Doc)
public boolean lockContainer(Transaction t, ContainerHandle container, boolean waitForLock, boolean forUpdate) throws StandardException(Code)(Java Doc)
public boolean lockRecordForRead(Transaction t, ContainerHandle container, RecordHandle record, boolean waitForLock, boolean forUpdate) throws StandardException(Code)(Java Doc)
public void lockRecordForRead(Latch latch, RecordHandle record, boolean forUpdate) throws StandardException(Code)(Java Doc)
public boolean lockRecordForWrite(Transaction t, RecordHandle record, boolean lockForInsert, boolean waitForLock) throws StandardException(Code)(Java Doc)
public void lockRecordForWrite(Latch latch, RecordHandle record) throws StandardException(Code)(Java Doc)
public void unlockContainer(Transaction t, ContainerHandle container)(Code)(Java Doc)
public void unlockRecordAfterRead(Transaction t, ContainerHandle container, RecordHandle record, boolean forUpdate, boolean row_qualified) throws StandardException(Code)(Java Doc)
public boolean zeroDurationLockRecordForWrite(Transaction t, RecordHandle record, boolean lockForPreviousKey, boolean waitForLock) throws StandardException(Code)(Java Doc)
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