public LockAttemptResult lock(
LockType requestType,
Locker locker,
boolean nonBlockingRequest,
MemoryBudget mb,
int lockTableIndex)
throws DatabaseException {
if (this.locker != null && this.locker != locker) {
/* Lock is already held by someone else so mutate. */
Lock newLock = new LockImpl(new LockInfo(this.locker, this.lockType));
return newLock.lock(requestType, locker, nonBlockingRequest, mb, lockTableIndex);
}
LockGrantType grant = null;
if (this.locker == null) {
this.locker = locker;
this.lockType = requestType;
grant = LockGrantType.NEW;
} else {
/* The requestor holds this lock. Check for upgrades. */
LockUpgrade upgrade = lockType.getUpgrade(requestType);
if (upgrade.getUpgrade() == null) {
grant = LockGrantType.EXISTING;
} else {
LockType upgradeType = upgrade.getUpgrade();
assert upgradeType != null;
this.lockType = upgradeType;
grant = (upgrade.getPromotion() ? LockGrantType.PROMOTION : LockGrantType.EXISTING);
}
}
return new LockAttemptResult(this, grant, false);
}
public boolean isOwner(Locker locker, LockType lockType) {
if (locker == this.locker) {
if (lockType == this.lockType) {
return true;
}
if (this.lockType != null) {
LockUpgrade upgrade = this.lockType.getUpgrade(lockType);
if (!upgrade.getPromotion()) {
return true;
}
}
} else {
return false;
}
return false;
}