/// <summary>
/// 11/7/2011
/// Checks whether a write lock requests conflicts with existing locks.
/// In the case that the item is locked due to recovery, we unlock the item and return false i.e. there are no conflicts.
/// </summary>
/// <param name = "requestedLock">The requested lock.</param>
/// <param name = "entry">The lock table entry to test.</param>
/// <returns>True if the requested write lock conflicts with any existing locks</returns>
/// <remarks>
/// Side effect: if the lock was held by the LM due to recovery, the lock will be removed
/// </remarks>
private bool WriteLockConflicts(Lock requestedLock, LockManagerTableEntry entry)
{
int? conflictingTransaction = entry.FindConflictsToWriteLock(requestedLock.TransactionId);
if (conflictingTransaction == null)
return false;
if (conflictingTransaction == int.MinValue)
{
entry.RemoveLock(int.MinValue);
return false;
}
return true;
}
/// <summary>
/// Date: 10/16/2011
/// Removes all locks which a transaction holds on a data item
/// </summary>
/// <param name = "entry">The lock entry.</param>
/// <param name = "transId">The transaction'd ID.</param>
/// <remarks>
/// Side effects: All locks held by this transaction for this data item are removed
/// </remarks>
private static void RemoveLock(LockManagerTableEntry entry, int transId)
{
entry.RemoveLock(transId);
}