/// <summary>
/// Releases the write lock held by the provided tx. If it is null then an
/// attempt to acquire the current transaction from the transaction manager
/// will be made. This is to make safe calling this method as an
/// <code>afterCompletion()</code> hook where the transaction context is not
/// necessarily available. If write count is zero and there are waiting
/// transactions in the queue they will be interrupted if they can acquire
/// the lock.
/// </summary>
//JAVA TO C# CONVERTER WARNING: Method 'throws' clauses are not available in C#:
//ORIGINAL LINE: synchronized void releaseWriteLock(Object tx) throws LockNotFoundException
internal virtual void ReleaseWriteLock(object tx)
{
lock (this)
{
TxLockElement tle = GetLockElement(tx);
if (tle.WriteCount == 0)
{
throw new LockNotFoundException("" + tx + " don't have writeLock");
}
_totalWriteCount = MathUtil.decrementExactNotPastZero(_totalWriteCount);
tle.WriteCount = MathUtil.decrementExactNotPastZero(tle.WriteCount);
if (tle.Free)
{
_ragManager.lockReleased(this, tx);
if (tle.HasNoRequests())
{
_txLockElementMap.Remove(tx);
}
}
// the threads in the waitingList cannot be currentThread
// so we only have to wake other elements if writeCount is down to zero
// (that is: If writeCount > 0 a waiting thread in the queue cannot be
// the thread that holds the write locks because then it would never
// have been put into wait mode)
if (_totalWriteCount == 0 && _waitingThreadList.Count > 0)
{
// wake elements in queue until a write lock is found or queue is
// empty
do
{
LockRequest lockRequest = _waitingThreadList.RemoveLast();
lockRequest.WaitingThread.Interrupt();
if (lockRequest.LockType == LockType.WRITE)
{
break;
}
} while (_waitingThreadList.Count > 0);
}
}
}
/// <summary>
/// Releases the read lock held by the provided transaction. If it is null then
/// an attempt to acquire the current transaction will be made. This is to
/// make safe calling the method from the context of an
/// <code>afterCompletion()</code> hook where the tx is locally stored and
/// not necessarily available through the tm. If there are waiting
/// transactions in the queue they will be interrupted if they can acquire
/// the lock.
/// </summary>
//JAVA TO C# CONVERTER WARNING: Method 'throws' clauses are not available in C#:
//ORIGINAL LINE: synchronized void releaseReadLock(Object tx) throws LockNotFoundException
internal virtual void ReleaseReadLock(object tx)
{
lock (this)
{
TxLockElement tle = GetLockElement(tx);
if (tle.ReadCount == 0)
{
throw new LockNotFoundException("" + tx + " don't have readLock");
}
_totalReadCount = MathUtil.decrementExactNotPastZero(_totalReadCount);
tle.ReadCount = MathUtil.decrementExactNotPastZero(tle.ReadCount);
if (tle.Free)
{
_ragManager.lockReleased(this, tx);
if (tle.HasNoRequests())
{
_txLockElementMap.Remove(tx);
}
}
if (_waitingThreadList.Count > 0)
{
LockRequest lockRequest = _waitingThreadList.Last.Value;
if (lockRequest.LockType == LockType.WRITE)
{
// this one is tricky...
// if readCount > 0 lockRequest either have to find a waiting read lock
// in the queue or a waiting write lock that has all read
// locks, if none of these are found it means that there
// is a (are) thread(s) that will release read lock(s) in the
// near future...
if (_totalReadCount == lockRequest.Element.readCount)
{
// found a write lock with all read locks
_waitingThreadList.RemoveLast();
lockRequest.WaitingThread.Interrupt();
}
else
{
IEnumerator <LockRequest> listItr = _waitingThreadList.listIterator(_waitingThreadList.LastIndexOf(lockRequest));
// hm am I doing the first all over again?
// think I am if cursor is at lastIndex + 0.5 oh well...
while (listItr.hasPrevious())
{
lockRequest = listItr.previous();
if (lockRequest.LockType == LockType.WRITE && _totalReadCount == lockRequest.Element.readCount)
{
// found a write lock with all read locks
//JAVA TO C# CONVERTER TODO TASK: .NET enumerators are read-only:
listItr.remove();
lockRequest.WaitingThread.Interrupt();
break;
}
else if (lockRequest.LockType == LockType.READ)
{
// found a read lock, let it do the job...
//JAVA TO C# CONVERTER TODO TASK: .NET enumerators are read-only:
listItr.remove();
lockRequest.WaitingThread.Interrupt();
}
}
}
}
else
{
// some thread may have the write lock and released a read lock
// if writeCount is down to zero lockRequest can interrupt the waiting
// read lock
if (_totalWriteCount == 0)
{
_waitingThreadList.RemoveLast();
lockRequest.WaitingThread.Interrupt();
}
}
}
}
}
