ojb.odmg.locking
Interface LockStrategy

All Known Implementing Classes:

AbstractLockStrategy

public interface LockStrategy

this interface defines method that a Locking Strategy must implement according to the transaction isolation level it represents. *

Method Summary

boolean	checkRead(TransactionImpl tx, java.lang.Object obj) checks whether the specified Object obj is read-locked by Transaction tx.
boolean	checkWrite(TransactionImpl tx, java.lang.Object obj) checks whether the specified Object obj is write-locked by Transaction tx.
boolean	readLock(TransactionImpl tx, java.lang.Object obj) acquire a read lock on Object obj for Transaction tx.
boolean	releaseLock(TransactionImpl tx, java.lang.Object obj) release a lock on Object obj for Transaction tx.
boolean	upgradeLock(TransactionImpl tx, java.lang.Object obj) acquire a lock upgrade (from read to write) lock on Object obj for Transaction tx.
boolean	writeLock(TransactionImpl tx, java.lang.Object obj) acquire a write lock on Object obj for Transaction tx.

Method Detail

readLock

public boolean readLock(TransactionImpl tx,
                        java.lang.Object obj)

acquire a read lock on Object obj for Transaction tx.

Parameters:

tx - the transaction requesting the lock

obj - the Object to be locked

Returns:

true if successful, else false

writeLock

public boolean writeLock(TransactionImpl tx,
                         java.lang.Object obj)

acquire a write lock on Object obj for Transaction tx.

Parameters:

tx - the transaction requesting the lock

obj - the Object to be locked

Returns:

true if successful, else false

upgradeLock

public boolean upgradeLock(TransactionImpl tx,
                           java.lang.Object obj)

acquire a lock upgrade (from read to write) lock on Object obj for Transaction tx.

Parameters:

tx - the transaction requesting the lock

obj - the Object to be locked

Returns:

true if successful, else false

releaseLock

public boolean releaseLock(TransactionImpl tx,
                           java.lang.Object obj)

release a lock on Object obj for Transaction tx.

Parameters:

tx - the transaction releasing the lock

obj - the Object to be unlocked

Returns:

true if successful, else false

checkRead

public boolean checkRead(TransactionImpl tx,
                         java.lang.Object obj)

checks whether the specified Object obj is read-locked by Transaction tx.

Parameters:

tx - the transaction

obj - the Object to be checked

Returns:

true if lock exists, else false

checkWrite

public boolean checkWrite(TransactionImpl tx,
                          java.lang.Object obj)

checks whether the specified Object obj is write-locked by Transaction tx.

Parameters:

tx - the transaction

obj - the Object to be checked

Returns:

true if lock exists, else false