public class BuddyLocker extends BasicLocker
In general, a BuddyLocker can be used whenever the primary (API) locker is in use, and we need to lock a node and release that lock before the primary locker transaction ends. In other words, for this particular lock we don't want to use two-phase locking. To accomplish that we use a separate BuddyLocker instance to hold the lock, while sharing locks with the primary locker. The BuddyLocker can be closed to release this particular lock, without releasing the other locks held by the primary locker.
In particular, a BuddyLocker is used when acquiring a RANGE_INSERT lock. RANGE_INSERT only needs to be held until the point we have inserted the new node into the BIN. A separate locker is therefore used so we can release that lock separately when the insertion into the BIN is complete. But the RANGE_INSERT lock must not conflict with locks held by the primary locker. So a BuddyLocker is used that shares locks with the primary locker.
defaultNoWait, deleteInfo, envImpl, handleLockToHandleMap, handleToHandleLockMap, id, lockManager, readUncommittedDefault, thread
Modifier | Constructor and Description |
---|---|
protected |
BuddyLocker(EnvironmentImpl env,
Locker buddy)
Creates a BuddyLocker.
|
Modifier and Type | Method and Description |
---|---|
static BuddyLocker |
createBuddyLocker(EnvironmentImpl env,
Locker buddy) |
long |
getLockTimeout()
Returns the lock timeout of the buddy locker, since this locker has no
independent timeout.
|
Txn |
getTxnLocker()
Forwards this call to the buddy locker.
|
long |
getTxnTimeout()
Returns the transaction timeout of the buddy locker, since this locker
has no independent timeout.
|
boolean |
isTimedOut()
Returns whether the buddy locker is timed out, since this locker has no
independent timeout.
|
void |
releaseNonTxnLocks()
Forwards this call to the base class and to the buddy locker.
|
void |
setLockTimeout(long timeout)
Sets the lock timeout of the buddy locker, since this locker has no
independent timeout.
|
void |
setTxnTimeout(long timeout)
Sets the transaction timeout of the buddy locker, since this locker has
no independent timeout.
|
boolean |
sharesLocksWith(Locker other)
Returns whether this locker can share locks with the given locker.
|
addLock, checkState, collectStats, createBasicLocker, createBasicLocker, createBasicLocker, createdNode, generateId, getAbortLsn, getWriteLockInfo, getWriteOwnerLocker, isReadCommittedIsolation, isSerializableIsolation, isTransactional, markDeleteAtTxnEnd, newNonTxnLocker, nonTxnOperationEnd, operationEnd, registerCursor, setHandleLockOwner, unRegisterCursor
addDeleteInfo, addToHandleMaps, demoteLock, dumpLockTable, getDefaultNoWait, getId, initApiReadLock, isHandleLockTransferrable, isReadUncommittedDefault, lock, nonBlockingLock, operationEnd, operationEnd, releaseLock, setOnlyAbortable, toString, transferHandleLock
protected BuddyLocker(EnvironmentImpl env, Locker buddy) throws DatabaseException
DatabaseException
public static BuddyLocker createBuddyLocker(EnvironmentImpl env, Locker buddy) throws DatabaseException
DatabaseException
public Txn getTxnLocker()
getTxnLocker
in class BasicLocker
public void releaseNonTxnLocks() throws DatabaseException
releaseNonTxnLocks
in class BasicLocker
DatabaseException
public boolean sharesLocksWith(Locker other)
sharesLocksWith
in class Locker
public long getLockTimeout()
getLockTimeout
in class Locker
public long getTxnTimeout()
getTxnTimeout
in class Locker
public void setLockTimeout(long timeout)
setLockTimeout
in class Locker
timeout
- The timeout value for the transaction lifetime, in
microseconds. A value of 0 disables timeouts for the transaction.public void setTxnTimeout(long timeout)
setTxnTimeout
in class Locker
timeout
- The timeout value for the transaction lifetime, in
microseconds. A value of 0 disables timeouts for the transaction.public boolean isTimedOut() throws DatabaseException
isTimedOut
in class Locker
DatabaseException