private bool ReadInProgress()
{
for (int i = 0; i < _readIndicator.Length; ++i)
{
if (RUnordered.Read(ref _readIndicator[i]) != 0)
{
return(true);
}
}
return(false);
}
internal void Enter()
{
if (RUnordered.Read(ref _isHeld) == 1)
{
int currentThreadId = Environment.CurrentManagedThreadId;
if (RUnordered.Read(ref _holdingThreadId) == currentThreadId)
{
return;
}
}
EnterSlow();
}
internal void EnterWriteLock()
{
RMonitor.Enter(_lockObj);
RUnordered.Write(ref _writerActive, 1);
RInterlocked.MemoryBarrierProcessWide();
while (ReadInProgress())
{
RE.Yield();
}
_snoop.BeginWrite();
return;
}
private void EnterSlow()
{
RMonitor.Enter(_lockObj);
RUnordered.Write(ref _holdingThreadId, Environment.CurrentManagedThreadId);
RInterlocked.MemoryBarrierProcessWide();
while (RUnordered.Read(ref _isHeld) == 1)
{
RE.Yield();
}
RUnordered.Write(ref _isHeld, 1);
RMonitor.Exit(_lockObj);
return;
}
internal void EnterReadLock()
{
var idx = GetReaderIndex();
RUnordered.Write(ref _readIndicator[idx], 1);
if (RUnordered.Read(ref _writerActive) == 1)
{
RUnordered.Write(ref _readIndicator[idx], 0);
RMonitor.Enter(_lockObj);
RUnordered.Write(ref _readIndicator[idx], 1);
RMonitor.Exit(_lockObj);
}
_snoop.BeginRead();
}
private LockCookie EnterSlow()
{
RMonitor.Enter(_lockObj);
var oldEntry = RUnordered.Read(ref _current);
RUnordered.Write(ref _current, new LockCookie(Environment.CurrentManagedThreadId));
RInterlocked.MemoryBarrierProcessWide();
while (oldEntry != null && RUnordered.Read(ref oldEntry.Taken) == 1)
{
RE.Yield();
}
var current = RUnordered.Read(ref _current);
RUnordered.Write(ref current.Taken, 1);
RMonitor.Exit(_lockObj);
return(current);
}
internal LockCookie Enter()
{
int currentThreadId = Environment.CurrentManagedThreadId;
LockCookie entry = RUnordered.Read(ref _current);
if (entry?.ThreadId == currentThreadId)
{
RUnordered.Write(ref entry.Taken, 1);
if (RVolatile.Read(ref _current) == entry)
{
return(entry);
}
RUnordered.Write(ref entry.Taken, 0);
}
return(EnterSlow());
}
public void Exit()
{
RUnordered.Write(ref _isHeld, 0);
}
public void Exit()
{
RUnordered.Write(ref Taken, 0);
}
internal LockCookie(int threadId)
{
ThreadId = threadId;
RUnordered.Write(ref Taken, 1);
}
internal void ExitReadLock()
{
RUnordered.Write(ref _readIndicator[_thisReaderIndex.Value], 0);
_snoop.EndRead();
}
internal void ExitWriteLock()
{
RUnordered.Write(ref _writerActive, 0);
_snoop.EndWrite();
RMonitor.Exit(_lockObj);
}
public int this[int idx] => RUnordered.Read(ref _data)[idx];
