public void Enqueue(WaitNode w)
{
if (_tail == null)
_head = _tail = w;
else
{
_tail.NextWaitNode = w;
_tail = w;
}
}
public void Enqueue(WaitNode w)
{
if (_tail == null)
{
_head = _tail = w;
}
else
{
_tail.NextWaitNode = w;
_tail = w;
}
}
// In backport 3.1 but not used.
//public void PutBack(WaitNode w)
//{
// w.NextWaitNode = _head;
// _head = w;
// if (_tail == null)
// _tail = w;
//}
public bool IsWaiting(Thread thread)
{
if (thread == null)
{
throw new ArgumentNullException("thread");
}
for (WaitNode node = _head; node != null; node = node.NextWaitNode)
{
if (node.IsWaiting && node.Owner == thread)
{
return(true);
}
}
return(false);
}
public WaitNode Dequeue()
{
if (_head == null)
{
return(null);
}
WaitNode w = _head;
_head = w.NextWaitNode;
if (_head == null)
{
_tail = null;
}
w.NextWaitNode = null;
return(w);
}
public WaitNode Dequeue()
{
if (_head == null) return null;
WaitNode w = _head;
_head = w.NextWaitNode;
if (_head == null) _tail = null;
w.NextWaitNode = null;
return w;
}
public override void LockInterruptibly()
{
Thread caller = Thread.CurrentThread;
lock (this)
{
if (GetHold(caller)) return;
}
WaitNode n = new WaitNode();
n.DoWait(this);
}
public override bool TryLock(TimeSpan timespan)
{
Thread caller = Thread.CurrentThread;
lock (this)
{
if (GetHold(caller)) return true;
}
WaitNode n = new WaitNode();
return n.DoTimedWait(this, timespan);
}
public void TakeOver(WaitNode node)
{
lock (this)
{
Debug.Assert(_holds == 1 && _owner == Thread.CurrentThread);
_owner = node.Owner;
}
}
public bool Recheck(WaitNode node)
{
Thread caller = Thread.CurrentThread;
lock (this)
{
if(GetHold(caller)) return true;
_wq.Enqueue(node);
return false;
}
}
public void TakeOver(WaitNode node) {}
public bool Recheck(WaitNode node) { return false; }
private void DoWait(Action<WaitNode> action)
{
int holdCount = Lock.HoldCount;
if (holdCount == 0)
{
throw new SynchronizationLockException();
}
WaitNode n = new WaitNode();
_wq.Enqueue(n);
for (int i = holdCount; i > 0; i--) Lock.Unlock();
try
{
action(n);
}
finally
{
for (int i = holdCount; i > 0; i--) Lock.Lock();
}
}
