package Examples;


/* This class exposes a weakness in the current coverage sensor: the handling of loops.
 * There is only one path through the class, but each time the loop is entered
 * Sensor.tick is called again.
 * 
 * E.g. if the loop is executed 25 times, the observed path will have 78 nodes:
 * 0 
 * 4 1 3 4 1 2 }
 * ...         } pattern repeats 12 times total: 12x6 = 72 nodes
 * 4 1 3 4 1 2 }
 * 4 1 3 
 * 4 5 
 * 
 * If the loop is repeated even 50 times, the Sensor will crash because
 * the heap grows too large.
 * 
 * This presents a real problem if an instrumented class where to have a inner loop that executed 50+ times.
 * 
 * A potential - but unsatisfying - solution would be to sense whether loops are entered
 * and then to not sense within the loop themselves.
 * This example also shows that multiple paths are possible within a loop, so such a solution would 
 * be inadequate.
 * 
 * To solve this we need to store observed edges in a set, not a list.
 * 
 * Or: we need to observe prime paths, not whole paths.
 * 
 * PROBLEM solved with TrieSensor
 * 
 */


public class ExponentialLoop {
	
	public int loop() {
		int node = 0;
		int count = 0;
		while(count++<25) { 
			if(count % 2 == 0)
				node = 1;
			else
				node = 2;
		}
		return node;
	}
}