A fast mutex struct

LightMutex.cs

using System;
using System.Threading;

struct LightMutex {
	private volatile Int32 inUse;
	
	public void Lock() {
		var spinWait = new SpinWait();
		while (Interlocked.Exchange(ref inUse, 1) == 1)
			spinWait.SpinOnce();
	}
	
	public void Unlock() {
		Interlocked.Exchange(ref inUse, 0);
	}
	
	public void Guard(Action body) {
		Lock();
		try {
			body();
		}
		finally {
			Unlock();
		}
	}
	
	public T Guard<T>(Func<T> body) {
		Lock();
		try {
			return body();
		}
		finally {
			Unlock();
		}
	}
}