// Allows one readLock to upgrade to a writeLock even if
// there are other readLocks as long as all other
// readLocks are also blocked in this method:
internal virtual void UpgradeReadToWrite()
{
lock (this)
{
System.Diagnostics.Debug.Assert(readCount > 0);
upgradeCount++;
while (readCount > upgradeCount || writeThread != null)
{
DoWait();
}
writeThread = ThreadClass.Current();
readCount--;
upgradeCount--;
}
}
internal virtual void AcquireWrite()
{
lock (this)
{
System.Diagnostics.Debug.Assert(writeThread != ThreadClass.Current());
while (writeThread != null || readCount > 0)
DoWait();
// We could have been closed while we were waiting:
EnsureOpen();
writeThread = ThreadClass.Current();
}
}
internal virtual void ReleaseWrite()
{
lock (this)
{
System.Diagnostics.Debug.Assert(ThreadClass.Current() == writeThread);
writeThread = null;
System.Threading.Monitor.PulseAll(this);
}
}
/// <summary>
/// Gets the currently running thread
/// </summary>
/// <returns>The currently running thread</returns>
public static ThreadClass Current()
{
if (This == null)
{
This = new ThreadClass();
This.Instance = Thread.CurrentThread;
}
return This;
}