/**
* Returns true if the LN at the given bin/index slot is permanently deleted. Returns false if it
* is not deleted, or if it is deleted but part of an unclosed, resurrected txn.
*
* <p>Enter/leave with bin field latched.
*/
private boolean isLNDeleted(BIN checkBin, int checkIndex) {
if (!checkBin.isEntryKnownDeleted(checkIndex) && !checkBin.isEntryPendingDeleted(checkIndex)) {
/* Not deleted. */
return false;
}
final long lsn = checkBin.getLsn(checkIndex);
if (lsn == DbLsn.NULL_LSN) {
/* Can discard a NULL_LSN entry without locking. */
return true;
}
/* Lock LSN to guarantee deletedness. */
final BasicLocker lockingTxn = BasicLocker.createBasicLocker(envImpl);
/* Don't allow this short-lived lock to be preempted/stolen. */
lockingTxn.setPreemptable(false);
try {
final LockResult lockRet =
lockingTxn.nonBlockingLock(
lsn, LockType.READ, false /*jumpAheadOfWaiters*/, checkBin.getDatabase());
if (lockRet.getLockGrant() == LockGrantType.DENIED) {
/* Is locked by a resurrected txn. */
return false;
}
return true;
} finally {
lockingTxn.operationEnd();
}
}
