private static readonly ReaderWriterLockSlim _cacheLocker = new ReaderWriterLockSlim(LockRecursionPolicy);
private static Dictionary<Type, ILog> _loggerCache = new Dictionary<Type, ILog>();


public static ILog GetLogger(Type type)
{
    ILog logger;

    _cacheLocker.EnterReadLock();

    try
    {
        if (_loggerCache.TryGetValue(type, out logger))
        {
            return logger;
        }
    }
    finally
    {
        _cacheLocker.ExitReadLock();
    }

    _cacheLocker.EnterWriteLock();
    try
    {
        // double check, as while the read-lock was released, the dictionary could have been modified
        if (_loggerCache.TryGetValue(type, out logger))
        {
            return logger;
        }

        logger = CreateLoggerForType(type);
        _loggerCache.Add(type, logger);
        return logger;
    }
    finally
    {
        _cacheLocker.ExitWriteLock();
    }
}