private void EnterLock()
{
if (_mode == LockMode.Read)
{
_logger.LogTrace(_pre + "Requested ReadLock");
if (!_lock.IsReadLockHeld && !_lock.IsWriteLockHeld && !_lock.IsUpgradeableReadLockHeld)
{
_logger.LogTrace(_pre + "Acquiring Readlock");
_dispose = () => { _lock.ExitReadLock(); };
_lock.EnterReadLock();
}
else
{
_logger.LogTrace(_pre + "Already holds {lock}", _lock.GetCurrentHeldLocks());
}
}
else if (_mode == LockMode.UpgradeableRead)
{
_logger.LogTrace(_pre + "Requested UpgradeableReadLock");
if (_lock.IsReadLockHeld)
{
var ex = new InvalidOperationException("The thread currently holds a readlock that prevents acquiring a upgradeable lock");
_logger.LogError(ex, _pre + "Cannot acquire UpgradeableReadLock");
throw ex;
}
else if (!_lock.IsUpgradeableReadLockHeld && !_lock.IsWriteLockHeld)
{
_logger.LogTrace(_pre + "Acquiring UpgradeableReadLock");
_dispose = () => _lock.ExitUpgradeableReadLock();
_lock.EnterUpgradeableReadLock();
}
else
{
_logger.LogTrace(_pre + "Already holds {lock}", _lock.GetCurrentHeldLocks());
}
}
else if (_mode == LockMode.Write)
{
_logger.LogTrace(_pre + "Requested WriteLock");
if (!_lock.IsReadLockHeld && !_lock.IsWriteLockHeld && !_lock.IsUpgradeableReadLockHeld)
{
_logger.LogTrace(_pre + "Acquiring WriteLock");
_dispose = () => _lock.ExitWriteLock();
_lock.EnterWriteLock();
}
else if (_lock.IsReadLockHeld)
{
var ex = new InvalidOperationException("The thread currently holds a readlock that is not upgradeable");
_logger.LogError(ex, _pre + "Cannot acquire WriteLock");
throw ex;
}
else if (_lock.IsUpgradeableReadLockHeld && !_lock.IsWriteLockHeld)
{
_logger.LogTrace(_pre + "Upgrading UpgradeableReadLock to WriteLock");
_dispose = () => _lock.ExitWriteLock();
_lock.EnterWriteLock();
}
else
{
_logger.LogTrace(_pre + "Already holds {lock}", _lock.GetCurrentHeldLocks());
}
}
else
{
var ex = new ArgumentException("Lockmode must either be Read, UpgradeableRead or Write", "mode");
_logger.LogError(ex, _pre + "Requested mode {mode}", _mode);
throw ex;
}
}