We have a serial port which is connected to hundreds of physical devices on the same wire. We have protocols like Modbus and Hart to handle the request and response between the application and devices. The question is related to managing the reference count of the channel. When no device is using the channel, the channel should be closed.

public class SerialPortChannel
{ 
   int refCount = 0;
   public void AddReference()
   {
      refCount++;
   }   


   public void ReleaseReference()
   {
      refCount--;
      if (refCount <= 0)
           this.ReleasePort(); //This close the serial port
   }   

}

For each device connected, we create a object for the device like

  device = new Device();
  device.Attach(channel);    //this calls channel.AddReference()

When the device disconnect,

  device.Detach(channel); //this calls channel.ReleaseReference()

I am not convinced by the reference count model. Are there any better way to handle this problem in .NET World?