var unsafeBuffer = MessagePackSerializer.SerializeUnsafe(foo);

            // simulate some work done on this same thread.
            //some other thread may use the MessagePackSerializer while this is going on.
            // is it safe to use unsafeBuffer later in this same thread?
            System.Threading.Thread.Sleep(1000);

            var safeBuffer = ArrayPool<byte>.Shared.Rent(unsafeBuffer.Count);
            try
            {
                unsafeBuffer.CopyTo(safeBuffer);
                // use the safe buffer...
            }
            finally
            {
                // after safe buffer is no more needed return it to pool
                ArrayPool<byte>.Shared.Return(safeBuffer);
            }