C# key-based locks

LockManager.cs

public class LockManager
{
    private readonly SemaphoreSlim[] _semaphores;

    public LockManager()
    {
        _semaphores = new SemaphoreSlim[1000];

        for(var i = 0; i < _semaphores.Length; i++)
        {
            _semaphores[i] = new SemaphoreSlim(1);
        }
    }

    public async Task<T> WaitForLockAsync<T>(string key, Func<Task<T>> func)
    {
        var semaphore = _semaphores[CalculateHash(key)];

        try
        {
            await semaphore.WaitAsync();
            return await func.Invoke();
        }
        finally
        {
            semaphore.Release();
        }
    }

    private uint CalculateHash(string key)
    {
        return (uint)key.GetHashCode() % (uint)_semaphores.Length;
    }
}