C#

JoeRip wrote:

Are changes to booleans already threadsafe?

Mark Churchill wrote:

Declare it as volatile

Daniel Grunwald wrote:

However, if you use the boolean for things like "run this code only once", then you have to lock/use Interlocked.CompareExchange to ensure that only the first thread to set the boolean to true runs the "run only once" code.

JoeRip wrote:

You can use an INT and treat it like a boolean, but that's pretty inelegant.

public struct MyBoolean
{
	public static readonly MyBoolean False = new MyBoolean(0);
	public static readonly MyBoolean True = new MyBoolean(1);
	
	int val;
	
	private MyBoolean(int val) {
		this.val = val;
	}
	
	public MyBoolean CompareExchange(MyBoolean value, MyBoolean comparand)
	{
		return new MyBoolean(Interlocked.CompareExchange(ref val, value.val, comparand.val));
	}
	
	public static implicit bool(MyBoolean a)
	{
		return a.val != 0;
	}
	
	public static implicit MyBoolean(bool a)
	{
		return a ? True : False;
	}
	
	public static bool operator ==(MyBoolean a, MyBoolean b)
	{
		return a.val == b.val;
	}
	// and the other operators...
}

if (ActiveMdiChild == null) return;
            var child = ActiveMdiChild as childformclass;
            child.isPoly = toolbarButton.Checked;

if (ActiveMdiChild == null) return;
            var child = ActiveMdiChild as childformclass;
            toolbarButton.Checked = child.isPoly;

ianhunt01 wrote:

I have got a MDI app where one of the childforms must be able to see the status of a RadioButton on a docked panel on the MDI from.