C#使用信号量 SemaphoreSlim 实现锁

同时刻只允许1个线程且最多只能有1个线程进入此逻辑

public async Task DoSomething()
{
    var slimlock = new SemaphoreSlim(1, 1);

    await slimlock.WaitAsync();

    try
    {
        // Do Something...
    }
    finally
    {
        slimlock.Release();
    }
}